Nitrile rubbers

FIELD: chemistry.

SUBSTANCE: invention relates to nitrile rubber, method of its obtaining and products, obtained from it. Claimed nitrile rubber contains structure repeat units of, at least, one α,β- unsaturated nitrile and, at least, one conjugated diene, and has ion indicator in range 0-60 ppm×mole/g. Nitrile rubber is obtained by emulsion polymerisation. Obtained latex, which contains nitrile rubber, is subjected to coagulation, and then coagulated nitrile rubber is washed. Polymerisation is carried out in presence of, at least, one alkylthiolate. Before coagulation value of latex pH is set at level, at least, 6, and then is coagulated in presence of, at least, one magnesium salt. Temperature of latex before adding at least one salt of magnesium is set at value 45°C. Obtained nitrile rubber is applied for obtaining capable of vulcanisation mixtures, which contain claimed rubber, at least, one linking agent and, if necessary, additional target additives to rubbers. Capable of vulcanisation mixtures are vulcanised by casting with obtaining cast products.

EFFECT: claimed nitrile rubbers have exclusive speed of vulcanisation, as well as exclusive properties of vulcanisates.

24 cl, 13 tbl, 17 ex

 

This invention relates to nitrile rubber, method thereof, mixtures, capable of vulcanization is based on the nitrile rubber, in addition to the method of production of vulcanizates of these mixtures, as well as any resulting vulcanizate.

Under nitrile rubbers, abbreviated also referred to as "NBR", understood as rubber, in which case we are talking about co - or terpolymer of at least one α, β-unsaturated nitrile, at least one conjugated diene and optionally one or more further copolymerizing monomers.

Such nitrile rubbers and the method of obtaining such rubbers are known, see for example W. Hofmann, Rubber Chem Technol, 36 (1963) 1 and Ullmann''s Encyclopedia of Industrial Chemtstry, VCH Verlagsgesellschaft, Weinheim, 1993, str-261. In these publications are not given indications of whether, and if so, in what way, can influence the rate of vulcanization of such rubbers and a set of properties, and in particular on the level of the module.

NBR receive by emulsion polymerization, and the first receive NBR-latex. Solid NBR-material extracted from this latex using coagulation. For coagulation are used salt and acid. About coagulation of the latex with the aid of metal salts known that for monovalent metal ions, for example in the form of sodium chloride, you must explicitly more electrolyte, is it for polyvalent metal ions, for example in the form of calcium chloride, magnesium chloride or aluminum sulfate (Kolloid-Z 154, 154 (1957)). From Houben-Weyl (1961), Methods der Org. Chemie, Makromolekulare Stoffe 1, str it is also known that the use of polyvalent metal ions leads to a more or less large inclusion of emulsifier in the product. According to Houben-Weyl (1961), Methods der Org. Chemie, Makromolekulare Stoffe 1, str "should be carefully washed not only used electrolytes, but also the final product must be free from catalysts and emulsifiers initial mixture. Already small remnants of electrolytes give eventually dull and muddy tin ware and cast products, spoil electrical properties and increase the absorptivity of the final product" (quote). In Houben-Weyl is not given indications as to be processed latex, to obtain a nitrile rubbers, which are vulcanized quickly and after vulcanization, have a high level module.

From DD 154702 known way radical copolymerization of butadiene and Acrylonitrile in the emulsion, which is regulated by special, accordingly computerized program dosing monomers, and the molecular weight regulator, such as tert-dodecylmercaptan, and who obtained latexes are processed by coagulation in an acidic environment in solid rubber. As the main advantage of the TBA method is specified, what is used as the rosin emulsifier and/or imokalee soap remains in the rubber resulting from the application of acids during coagulation, in other words, not washed, as in other ways. This in addition to the benefits of useful properties of NBR, specially advertised to improve the economic performance of the method and prevention of pollution through discharge of emulsifier wastewater. For the resulting butadiene-Acrylonitrile of copolymerization with 10-30 wt. -%, Acrylonitrile indicated that they have good elastic and low-temperature properties in combination with high resistance to swelling and favorable processability. Activities through which you can influence the rate of vulcanization of nitrile rubber and a set of properties of a vulcanized NBR, in the technical solution of this patent are not given.

Japanese patent JP 27902/73 (application 69 32, 322) it is known that using amines the coagulation of the latex with magnesium salts, for example by means of a combination of Diethylenetriamine and magnesium chloride decreased rate of premature vulcanization, and thus can improve the resistance to premature vulcanization of nitrile rubbers. From this prior art cannot be made then the following conclusions.

From German patent application DE-OS 23 32 096 famous is, that rubber can stand out from their aqueous dispersions using methyl cellulose and water soluble salts of alkali metals, alkaline earth metals, aluminum or zinc. As the preferred water-soluble salt is sodium chloride. As advantages of this method is described that coagulate receive almost entirely free from impurities, such as emulsifiers, catalysts and the like, since these impurities are removed with the water in the separation of coagulate, while still remaining in a small amount remains fully washed with additional water. Evidence on the rate of vulcanization of such rubbers obtained is not found. In the German patent application DE-OS 24 25 441 when electrolytic coagulation of rubber latex as an aid instead of methyl cellulose used is 0.1-10 wt. -%, (based on rubber) water-soluble alkylaryl with 2-4 carbon atoms or hydroxyethylcellulose in combination with 0.02 to 10 wt. -%, (based on rubber) water-soluble salts of alkali metals, alkaline earth metals, aluminum or zinc. Here is also used as the preferred water-soluble salt is sodium chloride. The coagulate is separated mechanically, if necessary, washed with water, and residual water is removed. Here is specified, h is about impurities in fact completely removed, as in the German patent application DE-OS 23 32 096, together with water in the separation of coagulate, while still remaining in a small amount remains completely washed out by flushing more water.

In the German patent application DE-OS 27 51 786 found that the selection and isolation rubbers from their aqueous dispersions is carried out with a low number (hydroxy)alkylaryl, if you are using a 0.02 to 0.25 wt. -%, water-soluble calcium salts. Again described as benefits that, according to this method turns out extremely clean coagulate, which is actually completely free of impurities, such as emulsifiers, catalysts and the like. These impurities are removed with the water in the separation of coagulate, while still remaining in a small amount of residues can be completely washed out with water. Also indicates that coagulation with calcium salt does not influence negatively on the properties of isolated rubber. Moreover, it turns out the rubber, which has the properties of vulcanization is not inflicted harm, and they fully satisfy the requirements. This is unexpected because the damage to the properties of the rubber were often observed when the polymer was separated from the dispersion by using a multivalent metal ions such as calcium ions or aluminum. As proof of the last statement is the example Houben-Weyl (1961), Methods der Org. Chemie, Makromolekulare line 1, str/485. Rubber from the patent DE-OS 27 51 786 opposite have no signs of inhibition or degradation of, for example, when premature vulcanization and/or when a complete cure.

None of the German application DE-OS 23 32 096, DE-OS 24 25 441 and DE-OS 27 51 786 data does not, what activities should be undertaken in order to achieve fast vulcanization and good properties of the vulcanizates.

As described in the above patents, the purpose of the German patent application DE-OS 30 43 688 is also more severe reductions necessary for coagulation of the latex, the amount of electrolyte. This is achieved according to the technical solution of the German patent DE-OS 30 43 688, where electrolytic coagulation of latex in addition to inorganic coagulate as an auxiliary means are used, or obtained from plant protein materials, or polysaccharides, such as starch, and optionally water-soluble polyamine connection. As inorganic coagulants are described preferably salts of alkaline or alkaline-earth metals. With the help of special additives is possible to reduce the need for quantitative coagulation of the latex, the amount of salt. In the German patent application DE-OS 3 043 688 not given instructions as receiving and/or processing of the nitrile to the of Ochakov can be achieved fast vulcanization.

In U.S. patent US-A-4, 920, 176 described and confirmed using experimental data that the coagulation of the nitrile rubber latexes using inorganic salts, such as sodium chloride or calcium chloride, is still very high in sodium, potassium and calcium, and also emulsifiers in nitrile rubber. This, however, is undesirable and in order to obtain the most pure nitrile rubber according to the patent US-A-4, 920, 176 in coagulation nitriloacetic latex instead of inorganic salts are water-soluble cationic polymers. Here it is, for example those based on epichlorohydrin and dimethylamine. Using this auxiliary means of achieving the goal is a significant reduction in the amount of salts remaining in the product. Resulting vulcanizates have a low swelling during storage in water, and high electrical resistance. In the description of the patent mentioned improved properties exclusively qualitatively explains the minimal content remaining in the product cations. Further explanation of the observed phenomena is not given. Also in U.S. patent US-A-4, 920, 176 does not meet the assumptions can, and if Yes, how by obtaining and processing nitrile rubbers to regulate the speed of vulcanization and the level of the module.

the spruce European patent application EP-A-1 369 436 is to produce the nitrile rubbers of high purity. In particular, the content of the remaining emulsifiers greatly reduced. Is very low specific cations as sodium, potassium, magnesium or calcium. Nitrile rubbers receive emulsion polymerization in the presence of salts of fatty acids and/or salts of resin acids as emulsifiers, and then carrying out the coagulation of the latex with an acid, optionally with the addition of precipitating agent. As acids can be used all mineral and organic acids, which allow you to set the desired pH value. As an additional precipitating agents used are usually alkali metal salts of organic acids. Then obtained by acid exposure fatty and resin acids are washed with an aqueous solution of alkali, and the polymer is exposed in conclusion, shear deformation, to establish a residual moisture content of less than or equal to 20%. European patent application EP-A-1 369 436 does not provide guidance for obtaining nitrile rubbers, which are fast curing and high modulus after vulcanization.

In the European patent applications EP-A-0 692 496, EP-A-0 779 301 and EP-A-0 779 300 in each case describes a nitrile rubber-based unsaturated nitrile and the conjugated dienos for all nitrile rubbers, is that all they have 10-60 wt. -%, unsaturated nitrile and a Mooney viscosity in the range of 15-150 or according to the European application EP-A-0 692 496 from 15-65, and all contain at least 0.03 mol alkylthio with 12-16 carbon atoms is 100 mol monomer structural units, and these ancilliary include at least three carbon atoms and one sulfur atom, which is directly connected with at least one tertiary carbon atom.

Getting nitrile rubber is carried out in each case in the presence of one suitably arranged alkylthiol with 12-16 carbon atoms as molecular weight regulator, which acts as the agent of the transfer chain ("Chain transfer agent") and thus is embedded as an end group in the polymer chain.

For nitrile rubber according to the European patent application EP-A-0 779 300 indicates that the width "AAN" (AN=Acrylonitrile) distribution of the composition of the unsaturated nitrile in the copolymer is from 3 to 20. The retrieval method is different from those described in European application EP-A-0 692 496 the fact that only 30-80 wt. -%, the total number of monomer is used to start the polymerization and the remaining amount of monomer is added only when the degree of progress of the polymerization in 20-70% of the mass.

For nitrile rubber according to European patent EP-A-0 79 301 is specified, they have 3-20 wt. -%, fractions with low molecular weight (srednekislye molecular mass Mnis less than 35.000). The retrieval method is different from those described in European application EP-A-0 692 496 the fact that only 10-95 wt. -%, alkylthiol added before the polymerization mixture of monomers, and the remaining amount alkylthiol is added only when the degree of progress of the polymerization in 20-70% of the mass.

In relation to the coagulation of the latex in all three European patent applications EP-A-0 692 496, EP-A-0 779 301 and EP-A-0 779 300 is described that can be used any coagulants. As inorganic coagulants are mentioned and used calcium chloride and aluminium chloride. According to EP-A-0 779 301 and EP-A-0 779 300 preferred form of execution is nitrile rubber, which is mainly halogen-free and is obtained by carrying out the coagulation of the latex in the presence of nonionic surface-active auxiliary means and with the use of metal salts, halogen-free, such as aluminum sulfate, magnesium sulfate and sodium sulfate. As the preferred specified coagulation using aluminum sulfate or magnesium sulfate. The obtained nitrile rubber, mainly halogen-free, has a halogen content constituting Maxim is 3 ppm

In comparative example 6 of European patent application EP-A-779 300 or comparative example 7 application EP-A-0 779 301 coagulation of the latex is carried out with a mixture of NaCl and CaCl2and CaCl2used in large quantities and the mass ratio of NaCl and CaCl2is 1:0.75 in. In relation to the time of premature vulcanization and the voltage level at 100% elongation is not detected significant difference in comparison with the other examples given in the respective tables 12 or 13.

To obtain these nitrile rubbers is essential according to the European patent applications EP-A-0 692 496, EP-A-0 779 300 and EP-A-0 779 301 that as the molecular weight regulator used alkylthiol in the form of compounds 2,2,4,6,6-pentamethylheptane-4-thiol and 2,2,4,6,6,8,8-heptamethylnonane-4-thiol. Here clearly indicates that when using conventional known tert-dodecylmercaptan as transfer agent chain nitrile rubbers obtained with inferior properties.

Received in European application EP-A-0 692 496, EP-A-0 779 300, and also in EP-A-0 779 301 nitrile rubber ensures that they have a useful set of properties that promote good machinability rubber mixtures and low pollution forms during processing. The resulting vulcanizates must have a good comb the nation of cold resistance and oil resistance, and possess good mechanical properties. In addition, make sure that when getting nitrile rubbers by a high degree of leakage of polymerization is more than 75%, preferably more than 80%, can be achieved with high productivity, and high-speed vulcanization during vulcanization with sulfur or with peroxides, in particular in the case of varieties NBR for processing by injection molding. Moreover, it is specified that the nitrile rubbers have a short time premature vulcanization and high density knitting. As evidence of rapid vulcanization is obtained according to the European application EP-A-0 692 496, EP-A-0 779 300 and EP-A-0 779 301 nitrile rubbers resort to time-premature vulcanization (the so-called "Scorch time" (measured as T5")), which is only one criterion of the rate of premature vulcanization. Regarding the overall speed of vulcanization and how, if necessary, it can affect not found any instructions. The density of crosslinking is described only by the maximum twisting (measured as Vmax).

In practice a short time premature vulcanization in General is not desirable, since the corresponding rubber mixtures according to the reason for such rapid premature vulcanization is not stable during processing. Fast who I am is premature vulcanization is not satisfactory when processed by injection molding. Crucial for cost-effective processing is the establishment of a short time cycles. For a short time cycles decisive is the difference in the rate of complete cure and premature vulcanization. It is measured as t90-t10where t90the time to reach 90% of the final vulcanization and t10the time, 10% of the final vulcanization. Through the application used in European applications EP-A-0 692 496, EP-A-0 779 300 and EP-A-0 779 301 controller 2,2,4,6,6-pentamethylheptane-4-thiol and 2,2,4,6,6,8,8-heptamethylnonane-4-thiol is absolutely impossible to install the fast speed of vulcanization, as well as high-level module.

In European application EP-A-0 692 496 inter alia States that to establish high-speed vulcanization already proposed many methods, such as using the minimum amount of emulsifier and the precipitating agent, so in NBR only the minimum amount of emulsifier and riveting tools. According to the European application EP-A-0 692 496 of these events, however, is not enough (page 2, line 22-28).

We can summarize the following that despite the large number of literary sources, to date, has not been described in any one way, which makes possible impact on the overall speed of vulcanization of nitrile to the of Ochakov, and in particular the impact on the speed difference of a complete cure and premature vulcanization (t90-t10). without harming the important properties of nitrile rubber, in particular the properties of the vulcanizates.

The objective of the invention is to provide a method by which receive nitrile rubbers, which in the further processing allows rapid and premature complete crosslinking, and thus lead to vulcanizates with good set of properties.

Unexpectedly, it was found that nitrile rubbers obtained with excellent speed vulcanization, as well as exceptional properties of vulcanizates, when emulsion polymerization is carried out with the special choice of the molecular weight regulator, and at the same time the coagulation of the latex is carried out in a special way, subject to the application, at least one magnesium salt as a coagulant, so that the nitrile rubbers because of these various measures how different special cations.

The subject of this invention, moreover, is a method for nitrile rubbers by emulsion polymerization of at least one α, β-unsaturated nitrile, at least one conjugated diene and at neobhodimosti or more further copolymerizing monomers, moreover, first obtained by polymerization containing a nitrile rubber latex is subjected to coagulation, and then the coagulated nitrile rubber is washed, characterized in that

(i) the emulsion polymerization is carried out in the presence of at least one alkylthiol, which contains 12 to 16 carbon atoms and at least three tertiary carbon atom, and a sulfur atom directly connected to one tertiary carbon atom, and

(ii) before coagulation pH value of the latex obtained by emulsion polymerization set at a level at least 6, and the temperature of the latex before adding the magnesium salt is set at the value of less than 45°C.

The subject of this invention is as nitrile rubber, which contains recurring structural units of at least one α, β-unsaturated nitrile, at least one conjugated diene and optionally one or more further copolymerizing monomers and has an ion index ("IKZ") of General formula (I) in the field 0-60 ppm×g/mol,

IKZ=3[c(Ca2+)40g/mol+c(Mg 2+)24g/mol]-[c(Na+)23g/mol+c(K+)39g/mol](I)

where c(CA2+), c(Mg2+), c(Na+) and c (+- the concentration of ions of calcium, magnesium, sodium and potassium in the nitrile rubber is indicated in ppm, and the concentration of magnesium ions(Mg2+) lies in the area of 50-250 ppm

These nitrile rubbers according to the invention have a high rate of vulcanization, characterized by a time difference of a complete cure and premature vulcanization (t90-t10), as well as the vulcanizates have good properties (in particular, high values of the module).

Such nitrile rubbers have hitherto not known from the prior art.

In the examples of European application EP-A-1 369 436 indicates the cations described for nitrile to the of Ochakov. Based on these data can be calculated ion indicators. They lie outside the observed values for the nitrile rubber according to the invention: example 1 of European application EP-A-1 369 436 ion indicator is to 12.4 ppm×mol/g, and in example 2 ion indicator equal to 7.8 ppm×mol/g at the same time, the European application EP-A-1 369 436 does not contain evidence that a mixture of cations has an impact on the overall speed of vulcanization, not to mention the fact that in EP-A-1 369 436, there is no indication, as a mixture of cations should look to nitrile rubber could be obtained with the desired high speeds premature and full vulcanization with simultaneous good set of properties.

In the examples of U.S. application US-A-4,920,176 processed nitrile rubber latexes with different precipitating means. For examples A-D, the latexes obtained in use as a coagulant NaCl, respectively CaCl2, which implies extremely low magnesium content. For examples E-l U.S. patent US-A-4, 920, 176 receive or ion indicator, which is much larger than that of the present invention, or a magnesium content, which lies below or above installed in this invention the field.

None of the examples of European applications EP-A-0 692 496, EP-A-0 779 300 and EP-A-0 779 301 salt is not used, the magician is Oia for coagulation of the latex. Without the use of magnesium salts in the coagulation magnesium content in the range of 50-250 ppm is not reachable.

Determination of cations:

For measurement of the content of cations to determine the ion indicator IKZ according to this invention, the following method has proved effective and has been applied: 0.5 g of nitrile rubber is subjected to decomposition by dry ashing at 550°C in a platinum crucible, followed by the dissolution of carbon black in hydrochloric acid. After appropriate dilution of the reaction solution with deionized water to determine the concentration of metals by means of optical emission spectrometry with inductively coupled plasma ICP-OES (inductively coupled plasma - optical emission spectrometry) at the following wavelengths:

calcium:317,933 nm
magnesium:285,213 nm
potassium:766,491 nm
sodium:589,592 nm

in relation to agreed with the acid matrix of the calibration solutions. Depending on the element concentration in the reaction solution or sensitivity of the measuring device is adjusted concentration tested and is controlled solutions used in each case, the wavelength in the linear region of the calibration (.Welz "Atomic Absorption Spectrometry", 2nd Ed., Verlag Chemie, Weinheim 1985)

Ion indicator according to the formula (I) metal content divided by the atomic weight of the corresponding metal. For this reason, the dimension IKZ is [ppm×mol/g].

Preferably the value of the ion indicator lies in the area of 10-55 ppm × mol/g, particularly preferably in the region of 10-50 ppm × mol/g

Nitrile rubber:

According to the invention nitrile rubbers contain recurring structural units of at least one α, β-unsaturated nitrile, at least one conjugated diene and optionally one or more further copolymerizing monomers.

The conjugated diene may be of different nature. Preferably used conjugate diene with 4-6 carbon atoms. Especially preferred are 1,3-butadiene, isoprene, 2,3-dimethylbutadiene, piperylene, 1,3-pentadiene or mixtures thereof. Especially preferred are 1,3-butadiene and isoprene or mixtures thereof. Highly preferred is 1,3-butadiene.

As the α, β-unsaturated nitrile may be used any known α, β-unsaturated nitrile, preferred are α, β-unsaturated NITRILES with 3-5 carbon atoms, such as Acrylonitrile, Methacrylonitrile, 1-chloroacrylonitrile, ethacrynate or mixtures thereof. Especially preferred is Acrylonitrile.

So the m way particularly preferred nitrile rubber is a copolymer of Acrylonitrile and 1,3-butadiene.

In addition to the conjugated diene and the α, β-unsaturated nitrile may be used one or more further copolymerizing monomers, such as α, β-unsaturated mono or dicarboxylic acids, their esters or amides. Such nitrile rubbers are referred to generally as karboksilirovanie nitrile rubbers, or also abbreviated "XNBR".

As the α, β-unsaturated mono or dicarboxylic acids can be used, such as fumaric acid, maleic acid, acrylic and methacrylic acid, crotonic and taconova acid. While preferred are maleic acid, acrylic and methacrylic acid and taconova acid.

As a complex ester of α, β-unsaturated carboxylic acids are used, such as complex alkilany ether complex alkoxyalkyl ether complex hydroxyalkyloxy ether or a mixture of them.

Particularly preferred complex alkylamino esters of α, β-ninasimone carboxylic acids are methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, n-butyl(meth)acrylate, t-butyl(meth)acrylate, hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, octyl(meth)acrylate and lauryl(meth)acrylate. In particular applies n-butyl acrylate.

Especially preferred is sustained fashion complex alkoxyalkyl esters of α, β-ninasimone carboxylic acids are methoxyethyl(meth)acrylate, ethoxyethyl(meth)acrylate and methoxyethyl(meth)acrylate. In particular applies methoxyethylamine.

Particularly preferred complex hydroxyalkylated esters of α, β-ninasimone carboxylic acids are hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate and hydroxybutyl(meth)acrylate.

As a complex ester of α, β-ninasimone carboxylic acids also are used, such as polyethylene glycol(meth)acrylate, polypropyleneglycol(meth)acrylate, glycidyl(meth)acrylate, epoxy(meth)acrylate and urethane(meth)acrylate.

Further monomers are vinylaromatic compounds such as styrene, α-methylsterols and vinylpyridine.

The proportion of the conjugated diene and the α, β-unsaturated nitrile in the nitrile rubber according to the invention can vary within wide limits. The proportion of the amount or amounts of conjugated dienes typically ranges from 20 to 95 wt. -%, preferably in the range from 40 to 90 wt. -%, particularly preferably in the range from 60 to 85% by mass, based on the entire polymer. The share of the sum or sums of α, β-unsaturated nitrile lies usually about 5 to 80 wt. -%, preferably about 10 to 60 wt. -%, especially preferably about 15 to 40 wt. -%, in the calculation on the entire polymer. The proportion of the monomers are added in each case to 100% of the mass.

Will complement the global monomers can find in quantities of from 0 to 40 wt%, preferably 0.1 to 40 wt. -%, particularly preferably 1-30 wt. -%, in the calculation on the entire polymer. In this case, the respective shares of conjugate(s) of the diene(s) and/or α, β-unsaturated(s) nitrile(s) are replaced with shares of this additional monomer, and share all monomers forth in each case stacks up to 100% of the mass.

If additional monomer used an ester of (meth)acrylic acid, the substitution is carried out usually in amounts from 1 to 25 wt. -%

If the additional monomer is used α, β-unsaturated mono or dicarboxylic acid, the substitution is carried out usually in amounts less than 10% of the mass.

The nitrogen content of the nitrile rubber according to the invention is determined according to DIN 53 625 by Kjeldahl method. Because of the content of polar comonomers nitrile rubbers are usually soluble in methyl ethyl ketone at 20°C for ≥85% of the mass.

Nitrile rubbers are the values of the Mooney viscosity (ML(1+4 @100°C) from 10 to 150, preferably from 20 to 100 units Mooney. Determine the value of Mooney viscosity (ML 1+4@100°C) is performed using a rheometer with parallel disks in accordance with DIN 53523/3 or ASTM D 1646 at 100°C.

The glass transition temperature nitrile rubbers are in the field from - 70°C to +10°C, mainly in the region of from 60°C to 0°.

Preferred are n trinnie rubbers according to the invention, having recurring structural units of Acrylonitrile, 1,3-butadiene, and optionally one or more further copolymerizing monomers. Also preferred are nitrile rubbers having recurring structural units of Acrylonitrile, 1,3-butadiene and one or more α, β-unsaturated mono or dicarboxylic acids, their esters or amides, and particularly preferred repeating structural units of the complex Olkiluoto ester of α, β-unsaturated carboxylic acids, highly preferred repeating units of methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, n-butyl(meth)acrylate, t-butyl(meth)acrylate, hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, octyl(meth)acrylate or lauryl(meth)acrylate.

The method of obtaining nitrile rubber:

Getting nitrile rubber is carried out according to the invention by emulsion polymerization method.

As emulsifiers can be used water-soluble salts of anionic emulsifiers or neutral emulsifiers. Preferably used anionic emulsifiers.

As anionic emulsifiers can be used, modified resin acids obtained by dimerization, disproportionation, hydrogenation and modification of mixtures of resin acids containing AB is tenovuo acid, neoabietic acid, Polustrovo acid, levopimaric acid. Particularly preferred modified resin acid is disproportionately resin acid (Ullmann''s Encyclopedia of Industrial Chemistry, 6. Edition, Band 31, str-355).

As anionic emulsifiers can also be used fatty acids. They contain from 6 to 22 carbon atoms per molecule. They can be completely saturated or contain one or more double bonds in the molecule. Examples of fatty acids are Caproic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid. Carboxylic acids are usually oils or fats, specific origin, such as castor oil, cotton seed, peanut oil, linseed oil, coconut oil, palm kernel oil, olive oil, rapeseed oil, soya oil, fish oil and beef fat, and so forth. (Ullmann''s Encyclopedia of Industrial Chemistry, 6. Edition, Band 13, p.75-108). Preferred carboxylic acids come from coconut oil, and beef fat, and are partially or fully gidrirovanie.

Such carboxylic acid-based modified resin acids or of fatty acids are used as soluble in the e lithium salts, sodium, potassium and ammonium. Sodium and potassium salts are preferred.

Anionic emulsifiers are, in addition, sulfonates, sulfates and phosphates, which are connected with organic residue. As organic residues are considered aliphatic, aromatic, alkylated aromatic compounds, condensed aromatic compounds, as connected through a methylene bridge aromatic compounds, and connected through a methylene bridge and condensed aromatic compounds can be optionally alkylated. The length of the alkyl chain comprises from 6 to 25 carbon atoms. The length of the alkyl chain connected with aromatic compounds lies between 3 and 12 carbon atoms.

Sulfates, sulfonates and phosphates are used as salts of lithium, sodium, potassium and ammonium. Preferred are salts of sodium, potassium and ammonium.

Examples of such sulfonates, sulfates and phosphates are sodium lauryl sulfate, alkylsulfonate sodium, alkylarylsulfonate sodium, sodium salt connected via a methylene bridge arylsulfonate, sodium salt of alkyl

naphthalenesulfonates, as well as those of sodium salt connected via a methylene bridge of naphthalenesulfonates, which can also be oligomerisation, and the degree of olig is merisalo lies in the area between 2-10. Usually alkylated naphthalenesulfonic acid and the United methylene bridge (optionally alkylated) naphthalenesulfonate acid are in the form of mixtures of isomers, which can contain more than 1 alphagroup (2-3 sulfopropyl) in the molecule. Especially preferred are laurilsulfate sodium, a mixture of sodium alkyl sulphonates, with 12-18 carbon atoms in the alkyl, alkylarylsulfonate sodium, diisobutyldimethoxysilane sodium, United methylene bridge mix polynaphthalene as the United methylene bridge mix arylsulfonate.

Neutral emulsifiers derived from products join ethylenoxide and propylenoxide to compounds with sufficiently acidic hydrogen. They belong, for example phenol, alkilirovanny phenol and alkylated amines. The average degree of polymerization of epoxides lies in the area between 2-20. Examples of neutral emulsifiers are ethoxylated nonylphenols with 8, 10 and 12 units of ethylene oxide. Neutral emulsifiers are usually not separately, and in combination with anionic emulsifiers.

Preferred are the sodium and potassium salts disproportionately abietic acids and partially hydrogenated fatty acids, fats, and mixtures thereof, sodium lauryl sulfate, alkylsulfonate sodium, alkylenes sulfonate sodium, as well as alkylated and connected through a methylene bridge naphthalenesulfonate acid.

Emulsifiers are used in amounts of from 0.2 to 15 wt., parts, preferably 0.5 to 12.5 mass., parts, particularly preferably 1.0 to 10 wt., parts per 100 mass., parts of the Monomeric mixture.

Emulsion polymerization is carried out with the use of these emulsifiers. If after completion of polymerization of the obtained latexes, which due to certain instability are prone to premature samokopiujace, also called emulsifiers can be used for additional stabilization of the latex. This may be necessary in particular to remove unreacted monomer by treatment with water vapor, and before storage of the latex.

To regulate the molecular weight of the obtained nitrile rubber is used, at least one alkylthiol, with 12-16 carbon atoms and containing at least three tertiary carbon atom, and a sulfur atom is directly linked to this tertiary carbon atom. These mercaptans may be used either individually or in mixtures. Suitable is, for example, the product of the joining of hydrogen sulfide to oligomerization propylene, in particular to the tetramer of propylene, or to oligomerization the isobutylene, about what bennoti to the trimer of isobutylene, which in the literature are commonly referred to as the tertiary dodecylmercaptan ("t-DDIVT).

Such alkylthiol or (isomeric mixtures of alkylthiols, either commercially available or can be obtained in specialist ways sufficiently described in the literature (see for example Japanese patent JP 07-316126, JP 07-316127 and JP 07-316128, and British application GB 823, 823 and GB 823, 824.)

A preferred example alkylthiol, which corresponds named above criteria, is 2,2,4,6,6,8,8-pentamethylheptane-4-thiol.

Especially preferred is also a new mixture of mercaptans with a 12-carbon atoms containing

- 2,2,4,6,6-pentamethylheptane-4,

- 2,4,4,6,6-pentamethylheptane-2,

- 2,3,4,6,6-pentamethylheptane-2 and

- 2,3,4,6,6-pentamethylheptane-3,

together with its preparation is described in the application filed on the same day the application of Lanxess Deutschland GmbH.

The preferred way these special new mix get through interaction of hydrogen sulfide with triisobutylene continuous manner at a temperature ranging from 0°C to -60°C, and

(a) the hydrogen sulfide before the interaction is being dried,

(b) used triisobutylene has a water content of at most 70 ppm,

(c) as the catalyst used boron TRIFLUORIDE in number to a maximum of 1.5 wt. -%, per used triisobutylene,

(d interaction is carried out in the absence of complexing with the boron TRIFLUORIDE compounds, and

(e) the reaction mixture to complete the interaction is mixed with the aqueous alkali solution, and remove the catalyst.

The molecular weight regulator is used in an amount of 0.05-3 wt., parts, preferably 0.1 to 1.5 mass., parts per 100 mass. parts of the Monomeric mixture. Be used as separate controllers, and a mixture of different regulators.

The dosage regulator molecular weight or a mixture of molecular weight regulators is carried out either at the beginning of the polymerization or in portions during the polymerization, and adding portions of the whole or of individual components of the mixture regulator during polymerization is preferred.

The molecular weight regulator can be because of their actions to a certain extent in the form of end groups in the nitrile rubber, i.e. nitrile rubber is known as end ancilliary. If using the previously described new mixture of mercaptans to 12 carbon atoms, thus we are talking about a respective end tigraph contained in the mixture of regulators thiols, i.e. end 2,2,4,6,6-pentamethylheptane-4-thio - and/or 2,4,4,6,6-pentamethylheptane-2-thio and/or 2,3,4,6,6 - pentamethylheptane-2-thio and/or 2,3,4,6,6-pentamethylheptane-3-thio-group.

To initiate emulsion polymerization using initiators polymer is saved, which dissociate with the formation of radicals. These include compounds containing a structural unit (peroxidase) or-N=N - structural unit (azo compounds).

To paracaseinate include peroxide, peroxodisulfate, peroxodisulfate, hydroperoxides, percolate, esters of percolat, anhydrides of percolat and peroxides with two organic residues. As salts nadkarni acid and adposting acid may be used salts of sodium, potassium and ammonium. Suitable hydroperoxides are, for example t-butylhydroperoxide, cumonherface and p-managedoperation. Suitable peroxides with two organic residues are Dibenzoyl peroxide, 2,4-dichlorobenzophenone, di-t-butylperoxide, dicumylperoxide, t-butylperbenzoate, t-butylmercaptan etc. Suitable azo compounds are azo-bis-isobutyronitrile, azo-bis-valeronitrile and azo-bis-cyclohexanediol.

Hydrogen peroxide, hydroperoxides, percolate, esters of percolat, persulfate and peroxodisulfate be used in combination with a reducing agent. Suitable reducing agents are sulfinate, sulfonate, sulfoxylate, dithionite, sulfite, metabisulfite, disulfit, sugar, urea, thiourea, xanthates, thioxanthene, salts of hydrazine, amines and derivatives AMI is a, such as aniline, dimethylaniline, monoethanolamine, diethanolamine or triethanolamine. Initiating system consisting of oxidant and reductant, called redox systems. When using redox systems are used often for more salts of compounds of transition metals such as iron, cobalt or Nickel in combination with a suitable complexing agents as sodium ethylenediaminetetraacetate, nitrilotriacetate sodium, as well as trisodium phosphate or tetracene diphosphate.

Preferred redox systems are, for example: 1) potassium peroxodisulfate in combination with triethanolamine, 2) ammonium peroxodisulfate in combination with sodium metabisulphite (Na2S2O5), 3) p-managedoperation / sodium formaldehydeinduced in combination with Fe-II-sulfate (FeSO4*H2O), sodium ethylenediaminetetra and trisodium phosphate; 4) cumonherface / sodium formaldehydeinduced in combination with Fe-II-sulfate (FeSO4*H2O), sodium ethylenediaminetetra and trisodium phosphate.

The amount of oxidizing agent is 0.001-1 wt., parts per 100 mass., parts of monomer. The molar amount of reducing agent is in the area between 50%-500% (based on the molar amount of the oxidizing agent.

Mol is th number of complexing agents depends on the amount used of the transition material, and is usually equimolar him.

For carrying out the polymerization of all or individual components of the initiator system is added at the beginning of the polymerization or during the polymerization.

Batch adding of all, as well as the individual components of the initiating system during polymerization is preferred. By successive addition is governed by the reaction rate.

The time of polymerization is in the range from 5 to 15 hours, and depends largely on the content of Acrylonitrile in the monomer mixture and the polymerization temperature.

The temperature of polymerization ranges from 0-30°C, preferably in the range from 5 to 25°C.

Upon reaching a conversion in the range of 50-90%, preferably in the range from 70 to 85% of the polymerization stops.

This is added to the reaction mixture breaker polymerization. For this purpose, suitable are, for example, dimethyldithiocarbamate, sodium nitrite, the mixture of dimethyldithiocarbamate and sodium nitrite, hydrazine and hydroxylamine and their derivatives salts such as hydrazine sulfate, hydroxylammonium sulfate, diethylhydroxylamine, diisopropylethylamine, water-soluble salt of hydroquinone, sodium dithionite, phenyl-α-naphtylamine and aromatic phenols, such as tert-butylpyrocatechol, or phenothiazine.

Used when emulsion the second polymerization amount of water lies in the range from between 100 and 900 mass., parts, preferably in the region from 120 to 500 mass parts, particularly preferably in the range from 150-400 mass., parts of water per 100 mass., parts of the Monomeric mixture.

The emulsion polymerization may be added to the salt water phase, to reduce the viscosity during the polymerization, for regulating the pH value, as well as to maintain at a certain level the pH-value. For this purpose usually salts of monovalent metals in the form of hydroxides of potassium and sodium, sodium sulfate, sodium carbonate, sodium hydrogen carbonate, lithium chloride, sodium chloride and potassium chloride. Preferred are sodium hydroxide and potassium, sodium bicarbonate and potassium chloride. The amount of this electrolyte is in the range of 0-1 wt., parts, preferably 0-0,5 wt., parts per 100 mass., parts of the Monomeric mixture.

The polymerization can be conducted either discretely or continuously in a cascade reactor with stirring.

To ensure an even flow of polymerization for the start of polymerization is used only part of the initiating system, and the remainder is added during the polymerization. Usually start the polymerization with 10-80 wt. -%, preferably 30-50% of the mass. the total amount of initiator. Is also possible to further add the individual components of the initiating system.

If Ho is it to obtain a chemically homogeneous products, the Acrylonitrile or butadiene add additionally, if the composition is outside the azeotrope butadiene/Acrylonitrile ratios. Additional dosing is preferred in the case of varieties nitrilebutadiene rubber containing Acrylonitrile, from 10 to 34, as well as for varieties with 40-50 wt. -%, Acrylonitrile (W. Hofmann, Rubber Chem. Technol. 36 (1963) 1). Additional dosing of conduct, as specified in the German patent application DD 154 702, preferably with computer-based management of a computing utility.

To remove unused monomers and volatile components of the final reaction, the latex is subjected to steam distillation. Using a temperature in the range from 70°C to 150°C, and at temperatures of <100°C reduce the pressure.

Before removing volatile components may be additional stabilization of the latex emulsifier. It is reasonable to use the above-mentioned emulsifiers in amounts of from 0.1 to 2.5 wt. -%, preferably 0.5 to 2.0,% wt., per 100 mass., parts of nitrile rubber.

Coagulation of the latex:

Before or during coagulation of the latex may be added to the latex one or more inhibitors of aging. Appropriate phenol, amine, and other inhibitors of aging.

Suitable phenolic inhibitor is mi ageing are alkylated phenols, modified styrene phenol, steric phenols employed as 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol (BHT), 2,6-di-tert-butyl-4-ethylphenol containing ester groups sterically difficult phenols containing simple thioether steric employed phenol, 2,2'-methylene-bis-(4-methyl-6-tert-butylphenol) (national Department of standardization), and steric employed thiobisphenol.

If staining rubber doesn't matter, used as amine inhibitors of aging, for example, a mixture of diaryl-p-phenylenediamines (DTPD), acceleratory diphenylamine (ODPA), phenyl-α-naphtylamine (PAN), phenyl-β-naphtylamine (PBN), preferred such on the basis of phenylenediamine. Examples for phenylendiamine are N-isopropyl-N'-phenyl-p-phenylenediamine, N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine (6PPD), N-1,4-dimethylpentyl-N'-phenyl-p-phenylenediamine (7PPD), N,N'-bis-1,4-(1,4-dimethylpentyl)-p-phenylenediamine (77PD) and so on.

Other inhibitors of aging include phosphites as Tris-(nonylphenyl)FOSFA, polymerized 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), 2-mercaptobenzimidazole (MBI), methyl-2-mercaptobenzimidazole (MMBI), zinc methylmercaptopurine (ZMMBI). The phosphites are mainly used in combination with phenolic inhibitors of aging. TMQ, MBI and MMBI are used primarily for grades nitrilebutadiene rubbers, which are vulcanized using p is reconyx connections.

For coagulation is used latex with a pH value of at least 6, preferably >6. If necessary, this pH value is adjusted by adding a base, preferably ammonia or sodium hydroxide or potassium.

Coagulation of the latex is carried out using at least one magnesium salt. Suitable, for example, is the use of magnesium chloride, magnesium sulphate and/or magnesium nitrate. Preferred is the use of magnesium chloride.

In addition to the use of at least one magnesium salt, preferably in the form of magnesium chloride, it is possible to use for coagulation also up to 5 wt%, of one or more other salts of one or more other divalent metals, based on the total number of all used for coagulation of salts.

Additionally, you may use up to X% of the mass, salts of monovalent metal, based on the total number of all used for coagulation salts, where X% of the mass, is 50 wt%, net wt. -%, the number of one or more salts of one or more other divalent metals, if any.

If no other salts of divalent metals are not present in coagulation, can be used thus for example up to 50 wt. -%, potassium salts, predpochtitel what about potassium chloride, and/or sodium salts, preferably sodium chloride, based on the total amount of salts used. Impurities in the form of calcium salts or supplements calcium salt, preferably calcium chloride, should not exceed 5 wt. -%, in the calculation of the total amount of all salts used, and through the presence of such calcium salts, respectively, decreases % mass amount of monovalent metal salts.

For coagulation of the latex is applied from 0.1 to 10 wt. -%, preferably from 0.5 to 5 wt%, of at least one salt of magnesium per nitrile rubber. The preferred way applied directly such salts of magnesium, which is necessary for complete coagulation of nitrile rubber, and which are determined primarily by aliquot part of a number of coagulation of the latex.

The concentration of the magnesium salt solution, preferably a solution of magnesium chloride, is usually from 0.1 to 35 wt. -%, mostly 0.5 to 30 wt. -%

An aqueous solution of at least one magnesium salt, preferably magnesium chloride, get with deionized water or not deionized, and thus containing calcium ions with water. When using calcium ions water is necessary to pay attention to the fact that the number of calcium from (a) possible impurities in mA is a silicon salt and (b) water used does not exceed in the amount of 5 wt. -%, mainly 1 wt. -%, in the calculation of the total amount of salts used.

Before coagulation of the latex, the pH of the latex is adjusted by adding base level, at least 6, preferably >6. To regulate the pH value is used, for example ammonia, sodium hydroxide and potassium.

Coagulation of the latex can be achieved by adding a salt solution to the latex, or alternative latex flow and the addition of the salt solution. Coagulation of the latex is carried out intermittently or continuously. The preferred coagulation is intermittently carried out using nozzles.

Is important for the method according to the invention that the temperature of the latex before adding the magnesium salt is set at the value of 45°C. Only in this case it is guaranteed that at the time of filing of salt latex forms a very fine coagulant. After adding salt can mix, if desired, be heated to a temperature of 100°C, preferably to a temperature in the range from 50 to 90°C. this heated up to higher temperatures produces large particles that can be filtered, with a diameter of >5 mm

In addition, the previously described salt or salts as electrolytes in coagulation can also be used precipitating agent. As precipitating means are considered, for example R is stormie polymers in water. They are non-ionic, anionic or cationic.

Examples of non-ionic polymer precipitating means are modified cellulose, such as hydroxyl Kil cellulose or methyl cellulose, and adducts of ethylene oxide and of propylene oxide with compounds with acidic hydrogen. Examples of compounds with acidic hydrogen are fatty acids, sugars such as sorbitol, monoglyceride and diglyceride fatty acids, phenol, alkylated phenols, (alkyl)phenol/formaldehyde condensates, etc. the addition Products of ethylene oxide and propylene oxide to these compounds may have a statistical distribution or in blocks. These products are preferred those in which with a decrease in temperature decreases the solubility. Characteristic of cloud temperature range from 0 to 100°C, in particular in the range from 20 to 70°C.

Examples of anionic polymer precipitating funds are Homo-and copolymers of (meth)acrylic acid, maleic acid, maleic anhydride, etc. Preferred is the sodium salt of polyacrylic acid.

Cationic polymer precipitating means usually based on polyamines, and Homo-and copolymers of (meth)acrylamide. Preferred are polymethacrylamide and polyamine, in particular on the basis of epichlorohydrin and dimethylamine is.

The amount of polymer precipitating means is 0.01-5 wt., parts, preferably 0.05 to 2.5 wt., parts per 100 mass., parts of nitrile rubber.

It is also possible to use other precipitating agents. It should however be noted that it is possible without problems to carry out the method according to the invention with the desired outcome in the absence of additional precipitating means, and, in particular, in the absence of alkylaryl with 1 to 4 atoms of carbon, hydroxyethylcellulose derived from plant protein materials, or polysaccharides, such as starch or a water-soluble compound polyamine.

Used for coagulation of the latex from the point of view of expediency has a concentration of solids in the range of 1% to 40%, preferably in the range from 5% - 35% and particularly preferably in the range of 15-30% of the mass.

The washing of the coagulated nitrile rubber:

After the coagulated nitrile rubber is usually presented in the form of so-called crumbs. Therefore, washing of the coagulated nitrile butadiene rubber is denoted as "rinse crumbs" (Krumelwasche). For washing these coagulated crumbs can be used with either deionized water, jet, or not deionized water, HB. If the coagulation of the latex, at least one magnesium salt no salt of calcium, the amount is the firmness of the possible areas (up to 5 wt. -%, of all the salts), has been effective in that when washing the coagulated NBR should be applied not deionized, and thus containing calcium ions water.

Washing is carried out at a temperature in the range from 15 to 90°C, preferably at a temperature in the range of 45 to 70°C.

The amount of wash water is 0.5-20 mass., parts, preferably 1-10 wt., parts and particularly preferably 1 to 5 mass parts per 100 mass., parts of nitrile rubber.

Preferably, rubber powder is subjected to multi-stage leaching, and between the individual washing stages from rubber crumbs partially drained water. Residual moisture crumbs between the individual washing stages is in the range of 5-50 wt%, preferably in the range of 7-25% of the mass. The number of washing stages is usually 1-7, preferably 1-3. Rinsing is carried out discretely and continuously. Preferably use a multi-stage, continuous way, and for the careful handling of water is preferred countercurrent rinsing.

The removal of water and drying:

After washing is usually dehydration nitriloacetate crumbs. The procedure usually do in two stages. In the first stage, the rubber crumb is subjected to mechanical pre-the Oia water. In the second stage, the remaining water is evaporated. As a preliminary removal of water and drying are preferably continuously. For mechanical preliminary removal of water suited / tube sheet screw presses, which water is squeezed sideways through the filter cracks or screws, and in which the mechanical dewatering is carried out against the flow of product (sealing principle).

On the regulation of the content of the remaining nitrile rubber cations optional and can be influenced by the degree of mechanical preliminary removal of water. This is effective particularly when applied to the so-called inefficient washing. Effective washing supplies already appropriate cations. The water content after mechanical removal of water is in the range from 5 to 25% of the mass. To regulate the remaining product mixture of cations was found to be suitable, if the water content after mechanical pre-dehydration is 5-15 wt. -%, in particular 5-10% of the mass.

Drying pre-dehydrated nitrile rubber is carried out in the drying oven with pseudosignal layer or in Plato-air dryer. Drying temperature range from 80 to 150°C. is Preferred drying setup temperatures the mode, and at the end of the drying process the temperature is reduced.

In an unexpected way nitrile rubbers according to the invention, which show the special content of cations, and thus ion indicator in the region, as well as special content of magnesium, have the desired high speed of vulcanization (the difference between full time and premature vulcanization) and the resulting vulcanizates have very good module.

The subject of the invention is therefore also the use of nitrile rubbers according to the invention for the manufacture capable of vulcanization mixtures containing at least one rubber according to the invention, at least one crosslinking agent and optionally further additives.

The manufacture of these are capable of vulcanization of the mixtures is carried out by mixing at least one nitrile rubber according to the invention, at least one cross-linking agent and optionally further additives.

As a cross-linking agent suitable are, for example, peroxide cross-linking agents, such as bis(2,4-dichlorobenzyl)peroxide, Dibenzoyl peroxide, bis(4-chlorobenzoyl)peroxide, 1,1-bis(t-BUTYLPEROXY)-3,3,5-trimethylcyclohexane, tert-butylperbenzoate, 2,2-bis(t-BUTYLPEROXY) - butene, 4,4-di-tert-butyl, peroxide valerat, dicumylperoxide, 2,5-dimethyl-2,5-di(t-BUTYLPEROXY)-hexane, tert-butylcumylperoxide, 1,3-bis(t-BUTYLPEROXY isopropyl)benzene, di-t-butylperoxide and 2,5-dimethyl-2,5-di(t-BUTYLPEROXY)-hexyne-3.

It may be advantageous, in addition of peroxide cross-linking agent to use further additives, which can be increased the efficiency of crosslinking. For this approach, for example, triallylisocyanurate, treelistener, trimethylolpropane three(meth)acrylate, triallylamine, etilenglikolevykh, potentialtheorie, trimethylolpropane, diacrylate zinc, zinc dimethacrylate, 1,2-polybutadiene or N,N-'m-phenylenedimaleimide.

The total number of cross-linking agent or cross-linking agents usually lies in the range from 1 to 20 mass 100 mass mixture, preferably in the range from 1.5 to 15 mass 100 mass mixture and particularly preferably in the range from 2 to 10 mass 100 mass mixture, based on the nitrile rubber.

As a cross-linking agent can also be used for sulfur in elemental soluble or insoluble forms or a sulfur donor.

As a donor sulfur consider, for example, discorporeality (DTDM), 2-morpholinobutyrophenone (MBSS), caprolactamate, dipentaerythrityl (DPTT), and tetramethylthiuramdisulphide (TMTD).

When the sulfur vulcanization of nitrile what's rubbers according to the invention, you can use additional additives which can be used to increase the efficiency of crosslinking. Fundamentally stapling can be done only sulfur or sulfur donor.

And contrast stitching nitrile rubbers according to the invention may be carried out only in the presence of the above additives, i.e. without the addition of elemental sulfur or sulfur donors.

As additives which can be used to increase the efficiency of crosslinking, suitable for example dithiocarbamate, tirami, thiazole, sulfenamide, xanthates, guanidine derivatives, caprolactam and thiourea derivatives.

As dithiocarbamates can be used, for example: ammonia dimethyldithiocarbamate, sodium diethyldithiocarbamate (of sdec), sodium dibutil-dithiocarbamate (SDBC), zinc dimethyldithiocarbamate (ZDMC), zinc diethyldithiocarbamate (ZDEC), zinc dibutyldithiocarbamate (ZDBC), zinc ethylenedicarboxylic (ZEPC), zinc dibenzyldithiocarbamate (ZBEC), zinc pentamethyldisiloxane (Z5MC), the tellurium diethyldithiocarbamate, Nickel dibutyldithiocarbamate, Nickel dimethyldithiocarbamate and zinc diisononylphthalate.

As Turnov can be used, for example: tetramethylthiuram disulfide (TMTD), tetramethylthiuram monosulfide (TMTM), diethyldiphenylurea disulfide, tetrabenzylthiuram disulfide, dipentylester tetras hid and tetraethylthiuram disulfide (TETD).

As thiazolo can for example be used: 2-mercaptobenzothiazoles (MW), dibenzothiazepine (MBTS), zinc mercaptobenzothiazoles (ZMBT) and copper 2-mercaptobenzothiazoles.

As sulfenamide derivatives may, for example, be used: N-cyclohexyl-2-benzothiazolesulfenamide (CBS), N-tert-butyl-2-benzothiazolesulfenamide (TBBS), N,N'-DICYCLOHEXYL-2-benzothiazolesulfenamide (DCBS), 2-morphosyntactical (MBS), N-oxydiethylene-N-tert-butylsulfonyl and oxydiethylene-N-acetylanthranilic.

As the xanthates can be used, for example: sodium dibutylaniline, zinc isopropylthioxanthone and zinc dibutylaniline.

As guanidine derivatives can be used, for example: diphenylguanidine (DPG), di-o-tolylguanidine (DOTG) and o-tolylboronic (OTBG).

As dithiophosphates can be used, for example: zinc dialkyldithiophosphate (chain length alkyl residues 2-16 of the atoms of the hydrocarbon), copper dialkyldithiophosphate (chain length alkyl residues 2-16 of the atoms of a hydrocarbon) and dithiophosphinate.

As caprolactam can be used, for example, dithio-bis-caprolactam.

As derivatives of thiourea can be used, for example N,N'-diphenylthiophene (DPTU), diethyltoluamide (DETU) and ethylendiamine (ETU).

As well as additives, where the Yat, for example: zinc diamondvision, hexamethylenetetramine, 1,3-bis(citratesildenafil)benzene and cyclic disulfide.

Named supplements as a means of stitching can be used both separately and in mixtures. Preferably used are the following substances for stitching nitrile rubber: sulfur, 2-mercaptobenzthiazole, tetramethylthiuram disulfide, tetramethylthiuram monosulfide, zinc dibenzyldithiocarbamate, dipentylester tetrasulfide, zinkdialkyldithiophosphates, discorporeality, the tellurium diethyldithiocarbamate, Nickel dibutyldithiocarbamate, zinc dibutyldithiocarbamate, zinc dimethyldithiocarbamate, dithio-bis-caprolactam.

The tool chain and the previously mentioned additives can in each case be used in the amount from about 0.05 to 10 mass 100 mass mixture, preferably from 0.1 to 8 mass 100 mass mixture, and particularly preferably 0.5 to 5 mass 100 mass mixture (individual dosing, in each case calculated on the active substance).

When grey stitching according to the invention optionally has a meaning in addition to the tool chain and the above-mentioned additives, the use of further inorganic or organic substances, such as zinc oxide, zinc carbonate, lead oxide, the oxide is magic, saturated or unsaturated organic fatty the acids and their zinc salts, polyhydric alcohols, aminoalcohols, such as triethanolamine, and also amines, such as dibutylamine, dicyclohexylamine, cyclohexylethylamine and polyetheramines.

Along with this can also be applied inhibitors of premature vulcanization. These include cyclohexylthiophthalimide (P), N,N' dinitrosopentamethylenetetramine (DNPT), phthalic anhydride (MOUTH) and diphenylnitrosamine. It is preferable to cyclohexylthiophthalimide (P).

In addition to adding a cross-linking agent or agents nitrile rubber according to the invention can also be mixed with other conventional additives for rubbers.

They include, for example, a typical and fairly well-known specialists substances, such as fillers, activators filling, antiozonant, aging inhibitor, antioxidant, technological modifier, softening oil, a plasticizer, a reinforcing material and a lubricant.

As fillers can be used, for example carbon black, silicic acid, barium sulfate, titanium dioxide, zinc oxide, calcium oxide, calcium carbonate, magnesium oxide, aluminum silicate, diatomaceous earth, talc, kaolin, bentonite, carbon nanotubes, Teflon, (the latter preferably in powder form) or silicates.

As activators filling taken into account especially organic silanes, such as, for example, the R VINYLTRIMETHOXYSILANE, vinylimidazoles, vinyltriethoxysilane, vinyltris(2-methoxy-ethoxy)silane, N-cyclohexyl-3-aminopropyltrimethoxysilane, 3-aminopropyl-trimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, dimethyldiethoxysilane, trimethylaluminium, isooctylmercaptoacetate, isooctylmercaptoacetate, hexadecyltrimethylammonium or (octadecyl)metaldimension. Further activators filling stand out, for example, surfactants such as triethanolamine and etilenglikoli with a molecular weight of from 74 to 10000 g/mol. The number of activators is usually 0-10 mass, including, per 100 mass nitrile rubber.

As an inhibitor of aging capable of vulcanization of the mixture may be added to substances that have already been disclosed in this application in the context of describing latex coagulation. They are used usually in amounts of from about 0 to 5 wt, hours, preferably from 0.5 to 3 mass, per 100 mass nitrile rubber.

As lubricants are suitable: saturated or partially unsaturated fatty acids and oleic acid and their derivatives (esters of fatty acids, salts of fatty acids, aliphatic alcohols, amides of fatty acids), which are preferably used as components of the mixture, and then the products are applied on the surface p of the ECC-shape, such as, for example, products based on low molecular weight compounds, silicone-based products of fluoropolymers, as well as products based on phenolic resins.

The lubricant is applied as a component of a mixture in amounts of from about 0-10 mass, preferably 0.5 to 5 mass per 100 mass nitrile rubber.

It is also possible reinforcement frame (fibers) of glass, according to the American patent application US-A-4, 826, 721, as well as the reinforcement with the help of cord fabric, of fibers of aliphatic and aromatic polyamides (nylon®, aramid®), polyesters, and natural fiber products.

The subject of the invention is, furthermore, a method of manufacturing molded products on the basis of at least one nitrile rubber according to the invention, which differs from that previously described is capable of vulcanization mixture vulcanizer by molding, preferably using injection molding.

The subject of the invention is, however, a special molded product, which can be obtained through the above-mentioned method of vulcanization.

Using this method can produce a large number of molded products such as a gasket, cap, hose, or membrane. Especially nitrile rubbers according to the invention with a special ion until what motor are suitable for the production of O-ring gaskets flat gaskets, rings, shaft seal, seal, seal cap, protective dust cap, plug seal, insulating hose (with and without the addition of PVC)hose, oil cooler, intake hose, hose, servo steering or pumping membrane.

Alternative to the direct production of molded parts based on the nitrile rubber according to the invention is possible when getting nitrile rubber according to the invention to add either (I) the reaction of metathesis or (ii) a metathesis reaction and subsequent hydrogenation or (iii) only the hydrogenation. Data metathesis reaction or hydrogenation enough known in the art and described in literature.

The metathesis reaction is known, for example, international application WO-A-02/100941 and WO-A-02/100905.

The hydrogenation can be carried out using homogeneous or heterogeneous hydrogenation catalysts. It is also possible to carry out the hydrogenation in situ, meaning in the same reaction vessel in which optionally has previously been destructive metathesis and without the necessity to isolate the degraded nitrile rubber. The catalytic hydrogenation just added to the reaction vessel.

Used catalysts are based usually on radii, PN is the situation or titanium, but it can also be platinum, iridium, palladium, rhenium, ruthenium, osmium, cobalt or copper, either in the form of metal, or preferably in the form of metal compounds (see for example patent application US-A-3, 700, 637, DE-A-25 39 132, EP-A-0 134 023, DE-OS 35 41 689, DE-OS 35 40 918, EP-A-0 298 386, DE-OS 35 29 252, DE-OS-34 33 392, US-A-4, 464, 515 and US-A-4, 503, 196)

Suitable catalysts and solvents for hydrogenation in the homogeneous phase are described in further, and it is also known from German application DE-A-25 39 132 and European application EP-A-0 471 250.

Selective hydrogenation can be achieved, for example, in the presence of a rhodium - or ruthenium-containing catalyst. Suitable for use is, for example, a catalyst of the General formula

(R1mB)lMXn,

where

M is ruthenium or rhodium,

R1are the same or different, and represent an alkyl group with 1-8 atoms of the hydrocarbon cycloalkyl group with 4-8 atoms of the hydrocarbon, aryl group with 6 to 15 atoms, hydrocarbon or aracelio group with 7 to 15 atoms of the hydrocarbon.

B is phosphorus, arsenic, sulfur or sulfoxide group S=O,

X represents hydrogen or an anion, preferably halogen or particularly preferably chlorine or bromine,

l is 2, 3 or 4,

m is 2 or 3, and

n is a number 1, 2 or 3, preferably 1 or 3. The preferred catalysts are Tris(Trifan fastin)-rhodium(1)chloride, Tris(triphenylphosphine)-rhodium(III)-chloride, Tris(dimethyl sulfoxide)-rhodium(III)chloride and tetrakis(triphenylphosphine)-rhodium-hydride of the formula (C6H5)3P)4RhH and the corresponding compounds in which the triphenylphosphine partly or completely replaced by tricyclohexylphosphine. The catalyst can be used in small quantities. Appropriate is a number in the range from 0.01 to 1 wt. -%, preferably in the range from 0.03 to 0.5 wt. -%, and particularly preferably in the range from 0.1 to 0.3 wt%, based on the weight of the polymer.

It usually makes sense to use the catalyst in conjunction with a co-catalyst, which is a ligand of the formula R1mB, and R1and have previously specified for catalyst values. Preferably m is 3, mean phosphorus, and the remainder R1may be the same or different. Preferably we are talking about co-catalysts with trialkylamine, tricyclohexyltin, triarylamine, trialkylamine, diaryl-monoalkylamines, diaryl-monocyclohexyl, dialkyl-manualnyj, dialkyl-monocyclohexyl, bicycloalkyl-manualnyj and bicycloalkyl-manualnyj remains.

Examples of co-catalysts, for example, in the American patent application US-A-4, 631, 315. The preferred co-catalyst is triphenylphosphine. Co-catalyst is used, preferred is considerable in amount of from 0.3 to 5 wt. -%, preferably from 0.5 to 4 wt. -%, based on the weight of hydrogenated nitrile rubber. Preferably the mass ratio registergui catalysts with co-catalyst is from 1:3 and 1:55, particularly preferably in the range from 1:5 to 1:45. Per 100 mass parts of hydrogenated nitrile rubber are applied respectively 0.1 to 33 mass parts of a co-catalyst, preferably 0.5 to 20 and particularly preferably 1-5 mass parts, in particular more than 2 but less than 5 mass parts of catalyst per 100 mass parts of hydrogenated nitrile rubber.

Practical implementation of this hydrogenation is quite well-known professionals from the American patent application US-A-6,683,136. The hydrogenation is usually carried out as follows: to gidriruemyi nitrile rubber in a solvent such as toluene or monochlorobenzene, 2-10 hours served hydrogen at a temperature in the range from 100 to 150°C and a pressure in the range from 50 to 150 bar.

Under hydrogenation in the context of this invention refers to the conversion of at least 50%, preferably 70-100%, particularly preferably 80-100% of the original nitrile rubber double bonds.

When using heterogeneous catalysts it is usually caused catalysts based on palladium, which caused for example n the coal, silicic acid, calcium carbonate or barium sulfate.

Obtained by the reaction of metathesis and/or hydrogenation of nitrile rubbers according to the invention, or optionally hydrogenated nitrile rubbers can be made as similar to nitrile rubber according to the invention is capable of vulcanization of the composition, and used to obtain vulcanizates and molded on the basis of such vulcanizates. These optionally hydrogenated nitrile rubbers have a Mooney viscosity (ML(1+4 @100°C.)) of 1-50, preferably 1-40 units Mooney.

Examples

General information:

I Determination of cations for ion indicator

For determination of cations 0.5 g of nitrile rubber is subjected to decomposition by dry ashing at 550°C in a platinum crucible, followed by the dissolution of carbon black in hydrochloric acid. After appropriate dilution of the reaction solution with deionized water to determine the concentration of metals by means of optical emission spectrometry with inductively coupled plasma ICP-OES (inductively coupled plasma - optical emission spectrometry) at the following wavelengths:

calcium:317,933 nm
magnesium:285,213 nm
potassium:766,491 nm
sodium:589,592 nm

in relation to agreed with the acid matrix of the calibration solutions. Depending on the element concentration in the reaction solution or sensitivity of the measuring device is adjusted concentrations of test solutions used in each case, the wavelength in the linear region of the calibration (B. Welz "Atomic Absorption Spectrometry", 2nd Ed., Verlag Chemie, Weinheim 1985)

II the Rate of premature vulcanization and the speed of vulcanization

The rate of premature vulcanization (Mooneyscorch) is determined by using a rheometer with parallel disks in accordance with DIN 53 523 at 120°C. is used To define a small rotor (S). MS 5 (120°C) mean time in minutes during which the Muni index increases by 5 units Mooney in relation to the minimum value.

The rate of vulcanization is determined according to DIN 53 529, part 3 at a temperature of 160°C by using a rheometer (Monsanto company (MDR 2000E) as the difference between t90-t10where t10and t90the time of vulcanization, in which the degree of the final vulcanization 10%, or 90%.

The parameters of vulcanization of the mixtures are determined by a rheometer at a temperature of 160°C in accordance with DIN 53 529. That is they way to determine the characteristic time of vulcanization t 10and t90.

III Mechanical properties

The mechanical properties of rubbers (such as voltage magnitude at different strain, ultimate tensile strength and ultimate elongation) of the vulcanizates are determined in accordance with DIN 53 504.

A Production of NBR by emulsion polymerization

On the basis given in the following table 1 formulations made two NBR-rubber latex, A and B. All the substances applied are specified in the mass parts per 100 mass parts of the monomer mixture. The polymerization is carried out at a temperature of 13°C, duration of 13.5 hours to achieve the degree of polymerization of 80%.

Table 1:
Latex - no.AB
Butadiene7373
Acrylnitrile2727
The total amount of water220220
Erkantol® BXG1)to 3.67to 3.67
Baykanol® PQ2} 1,101,10
Potassium salt of fatty acid of coconut oil0,730,73
KON0,050,05
t-DDM7)0,24/0,240,24/0,24
Cliperectile3)0,39/0,190,39/0,19
Tris-(α-hydroxyethyl)-amine4)0,550,55
Sodium-dithionite5)1,191,0
Diethylhydroxylamine00,5
The potassium hydroxide1,281,28
Vulkanox® KB6)1,251,25
1)the sodium salt of mono and desulfonatronum naphthalenesulfonic acids, which contain isobutyleneisoprene residues (Erkantol® BXG)
2)the sodium salt of IU is safe bis-naphthalenesulfonate (Baykanol® PQ; Lanxess Deutschland GmbH)
3)catalogue number Aldrich: 21,622-4
4)catalogue number Aldrich: T5, 830-0
5)catalogue number Aldrich: 15,795-3
6)2,6-di-tert-butyl-p-basal; Lanxess Deutschland GmbH
7)t-DDM: (tertiary dodecylmercaptan): a mixture of mercaptans from 12 carbon atoms to Lanxess Deutschland GmbH

In the above table 1, one of the lines for nitrile rubbers A and B are two values, this means that the total number of relevant applied substances were not added in one portion, and the first part was added at the start of polymerization and the second part was added later. The conversion, which was implemented additional dosing, are given next.

Receipt NBR-latex was carried out periodic manner in an autoclave with stirrer volume of 2 m3. When loading the autoclave in each case used 350 kg of the monomer mixture and the total amount of water in the amount of 700 kg. of this amount of water was loaded into the autoclave 609 kg with emulsifiers (Erkantol® BXG (12,85 kg), Baykanol® PQ (3,85 kg) and potassium salt of fatty acids of coconut oil (2,56 kg) and 84 g of potassium hydroxide and blew the shock of nitrogen. After purging with nitrogen was added to the reactor destabilized monomers (255,5 kg of butadiene 94.5 kg Acrylonitrile) and the first installation of the regulator of the molecular weight of t-DDM (0,84 kg). Then the reactor was closed. The remaining amount of water (161 kg) were used to produce an aqueous solution of Tris-(α-hydroxyethyl)-amine, potassium of peroxodisulfate and stopping the reaction solution. By adding an aqueous solution 1,365 kg of potassium peroxodisulfate (corresponding to 0.39 wt., parts according to table 1) and 1,925 kg Tris-(α-hydroxyethyl)-amine (corresponding to 0.55 mass., parts according to table 1) was launched polymerization at 17°C, and at all times maintained this temperature. The progress of the polymerization was followed by gravimetric determination of the conversion. When the degree of progress of the polymerization of 15% was subsequently added 0,84 kg regulator of t-DDM (corresponding to 0.24 mass., parts according to table 1) and 0,665 kg of potassium peroxodisulfate (corresponding to 0.19 mass., parts according to table 1). Upon reaching a conversion of 80% (13.5 hours) the polymerization was stopped by adding aqueous solution of sodium dithionite and potassium hydroxide (latex A) or, respectively, the sodium dithionite/(N,N-diethylhydroxylamine (DEHA) and potassium hydroxide (latex B). Unreacted monomers and other volatile component parts is removed by distillation with steam.

Characteristics of both latexes combined in the following table 2.

Latex - no.AB
Particle diameter (d50) [nm]360370
Solid content [wt. -%]18,920,4
PH8,9the 9.7
The content of Acrylonitrile [wt. -%]28,928,0

Before coagulation of the corresponding NBR-latex was mixed in each case with a 50%dispersion of Vulkanox®KB (1.25% of the mass Vulkanox®KB per solid NBR-latex). Vulkanox®-KB-dispersion was obtained in advance by using Ultraturrax at 95-98°C and the programme consisted of:

360 g of deionized water ("LW water")

40 g of ethoxylated Nonylphenol (NP10 Lanxess

Deutschland GmbH)

400 g of Vulkanox®KB Lanxess Deutschland GmbH

B Processing latex

The concentration of the salt solution and used for the deposition amount of salt is calculated in each case excluding water of crystallization. Used for coagulation lat the KSA salt, the concentration of salt solutions, the amount of salts used in the calculation of the NBR rubber, the temperature of coagulation temperature when washing, as well as the duration of leaching are indicated in the following tables.

The amount of salt in each case was determined so that the rubber powder obtained by coagulation of the latex, was more than 5 mm, so that in the subsequent rinsing it didn't wash away wash stream. In each case processed 25 kg of latex in the solid. Coagulation of the latex was carried out intermittently in mixing, open vessel with a volume of 100 liters. This latex was placed in a container for coagulation, and then heated to temperatures shown in tables 3 and 4 in line 6, if the latex was kept at a temperature above 20°C, then added with stirring an aqueous salt solution at the same temperature, and then the reaction mixture was heated to the temperature data in tables 3 and 4 in line 7. For leaching rubber crumbs used 100 liter capacity is operating the inlet and outlet channel. On the inner side of the tank were two guides, so before flushing the drain could be blocked by the filter (the size of the holes 2 mm), so that the coagulated crumb when washing is not washed out. Leaching was carried out described the experiments here with a constant throughput of water 200 l/h For washing used as deionized (DL)and normal tap water (HB).

In most experiments before washing obtained by precipitation of the latex liquid phase is removed from the vessel to coagulate before washing, i.e. latex liquid phase was removed by diluting the wash.

Used when washing the rubber crumbs standard conditions (water temperature washing time, washing and so on) are provided in the following tables.

In each case, the conditions applied for processing latex nitrile rubbers a and b are collected in tables 3, 4 and 5.

In column 4 of tables 3, 4 and 5 under the concentration salt solution are indicated by letters "DV" or "HB" characterizing the type of water that was used for the salt solution.

NV
Table 3:
Examples 1-8 according to the invention (coagulation of the latex with MgCl2)
ExampleProperties of latexDeposition conditionsTerms of flush
Type latexpH The type of saltThe concentration of the salt solution [wt. -%]The amount of salt per NBR [wt. -%]The temperature of the latex by adding salt [°C]Tcmperature dispersion of rubber crumbs after heating [°C]The type of waterT [°C]Time [h]
1inthe 9.7MgCl20,8/NV82020NV205
2inthe 9.7MgCl20,8/NV82020LW205
3Inthe 9.7MgCl21,6/NV162020205
4And8,4MgCl220/LW1,94545NV605
5Inthe 9.7MgCl220/NR2,372045NV608
6Inthe 9.7MgCl220/NR2,372070NV608
7Inthe 9.7MgCl220/NR2,372080608
8Inthe 9.7MgCl220/NR2,372090NV608

Table 4:
Comparative examples 9-13 (coagulation of the latex with MgCl2but the temperature of the latex by adding the salt solution to 60°C)
ExampleProperties of latexDeposition conditionsTerms of flush
Type latexpHThe type of saltThe concentration of salt solution [wt. -%]The amount of salt per NBR [wt. -%]The temperature of the latex by adding salt [°C]The temperature dispersion of rubber crumbs after heating [°C] Temperature [°C]Time
9A8,4MgCl230/LW1,9 16060NV602,5
10A8,4MgCl230/LW1.96060NV202,5
11A8,4MgCl230/LW1,96060NV205,0
12A8,4MgCl215/LW1,960 60NV452,5
13Bthe 9.7MgCl215/LW1,96069NV455,0

Table 5:
Comparative examples 14-18 (coagulation of the latex with CaCl2
ExampleProperties of latexDeposition conditionsTerms of flush
Type latexpHThe type of saltThe concentration of salt solution [wt. -%]The amount of salt per NBR [wt. -%]The temperature of the latex by adding salt [°C]The temperature dispersion of rubber crumbs after heating [°C]The type of water Temperature [°C]Time [hours]
14A8,4CaCl20,332020LW20the 3.8
15A8,4CaCl20,662020LW20the 3.8
16A8,4CaCl21,2122020LW203,5
17Aof 5.81CaCl21,2122020The 203,4
1)Determination of pH was carried out in the latex by adding HCl before adding CaCl2

After washing the rubber crumb was removed using a sieve, and sealing screw previously obezvozhivani to a residual moisture content of 5-15% of the mass.

Final drying pre-dehydrated samples of rubber were breaks in a ventilated oven at 70°C to a residual moisture content of <1.5% of the mass.

For determination of cations aliquot part of the rubber sample solely in accordance with DIN 53 568 and measured by atomic absorption spectroscopy in accordance with DIN 51401.

The cations and ionic comparative indicator according to the invention or nitrile rubbers from tables 3, 4 and 5 are given in tables 7, 8 and 9.

Table 7:
The content of the cation / Ion NBR indicator according to the invention from table 3
ExampleThe type of saltThe cations
Ca [ppm] Mg [ppm]Na [ppm]K [ppm]IKZ
1MgCl24909810548
2MgCl21631646332
3MgCl243013616748
4MgCl257557642047
5MgCl24008329839
6MgCl2215101 471426
7MgCl2225107511628
8MgCl2171111361125

Table 8:
The content of the cation / Ion indicator comparative NBR table 4
ExampleThe type of saltThe cations
Ca [ppm]Mg [ppm]Na [ppm]K [ppm]IKZ
9MgCl24502454212 62
10MgCl2455270622065
11MgCl2475220411461
12MgCl2345440812277
13MgCl2475365511579
Table 9:
The content of the cation / Ion indicator comparative NBR 1 of table 5
ExampleThe type with whom Lee The cations
Ca [ppm]Mg [ppm]Na [ppm]K [ppm]IKZ
14CaCl21190617189
15CaCl21290312197
16CaCl2124026193
17CaCl21235281 93

On the basis described in tables 3, 4 and 5 nitrile rubbers are manufactured in a laboratory mixer with a capacity of 1.5 liters according to table 10 rubber mix, and separate components of a mixture are mixed in the specified in the table order. All component parts of the mixture are indicated in mass., parts per 100 mass., parts of nitrile rubber.

Table 10:
The composition of the rubber mixtures
An integral part of mixtureQuantity in mass, units
NBR100,0
Stearic acid2,0
Zinc oxide:5,0
Carbon black N33040,0
The phenol/formaldehyde resin (Plastikator® FH)5,0
N-cyclohexyl-benzothiazolesulfenamide (Vulkacit® CZ)0,9
Sulfur1,5

The rate of vulcanization of the mixtures are defined in the rheometer at a temperature of 160°C in accordance with DIN 53 529 using the and rheometer company Monsanto MDR 2000TH. In this way defined characteristic vulcanization time t10and t90.

In accordance with DIN 53 529, part 3, means:

t10: the time to reach 10% conversion

t90: time to reach 90% conversion

Obtaining required for further measurements experienced a vulcanized products were made under pressure from the hydraulic pressure 120 bar 30 min at 160°C. the vulcanizates were determined using tensile test in accordance with DIN 53504 the voltage at 300% strain (ATO), ultimate tensile stress (σmax) and ultimate elongation (εb).

Table 11:
The parameters of vulcanization and properties of nitrile rubber vulcanizates according to the invention from table 3
ExampleThe type of saltIKZVulcanizationProperties of vulcanizates
MS 5 (120°C) [min]t10[c]t90[c]t90-t10[with]σ300[MPa]σ max[MPa]εb[%]
1MgCl248486,511,55,08,123,2616
2MgCl232476,511,75,28,222,7600
3MgCl248476,511,75,2822,6612
4MgCl24746711,9a 4.97,822,1610
5 MgCl239467,312,2a 4.98,221,7576
6MgCl226437,111,94,88,623,4595
7MgCl228416,611,5a 4.98,723,1577
8MgCl225426,912,25,38,820,8538

Table 12:
Couples who points vulcanization and properties of vulcanizates comparative nitrile rubbers table 4
ExampleThe type of saltIKZVulcanizationProperties of vulcanizates
MS 5 (120°C) [min]t10[c]t90[c]t90-t10[c]σ300[MPa]σmax[MPa]εb[%]
9MgCl262527,914,26,37,422,0622
10MgCl265547,914,16,27,321,8627
11 MgCl261537,514,57,07,321,3621
12MgCl277548,515,16,66,923,0666
13MgCl279547,814,66,87,122,1641
Table 13:
The parameters of vulcanization and properties of vulcanizates sravnitelnyh nitrile rubbers from table 5
ExampleThe type of salt IKZVulcanizationProperties of vulcanizates
MS 5 (120°C) [min]t10[c]t90[c]t90-t10[c]σ300[MPa]σmax[MPa]εb[%]
14CaCl289567,114,77,67,421,0608
15CaCl297598,216,78,57,1a 21.5649
16CaCl293568,0 18,210,27,121,6648
17CaCl293628,717,68,97,021,6651

In tables 11, 12 and 13 shows that the rate of premature vulcanization, the speed of vulcanization (t90-t10) and the properties of the vulcanizates, in particular the voltage value at 300% elongation (σ300) essentially depend on the concentrations and relative ratios of cations in nitrile rubber. Properties of nitrile rubbers is determined by ion indicator and magnesium content. Also it is shown that the NBR-latex coagulated with magnesium chloride according to the invention have a low rate of premature vulcanization, short reaction time and high voltage value at 300% elongation than comparative nitrile rubbers.

1. Nitrile rubber, which contains recurring structural units of at least one α,β-unsaturated nitrile with shares, make up is she from 5 to 80 wt.%, and at least one conjugated diene with a share constituting from 20 to 95 wt.%, and has an ion index "IKZ" the General formula (I) in the field 0-60 ppm·mol/g
IKZ=3[c(Ca2+)40g/mol+c(Mg2+)24g/mol]-[c(Na+)23g/mol+c(K+)39g/mol],(I)
where(CA2+), c(Mg2+), c(Na+) and(K+- the concentration of ions of calcium, magnesium, sodium and potassium in the nitrile rubber is indicated in ppm, and the concentration of ions
magnesium c(Mg2+) lies in the area of 50-250 ppm

2. Nitrile rubber according to claim 1 with a value of ion indicators of the I, lying in the field 10-55 ppm·mol/g, preferably in the region of 10-50 ppm·mol/g

3. Nitrile rubber according to claim 1, which has recurring structural units of Acrylonitrile, 1,3-butadiene, and optionally, if necessary, one or more further copolymerizing monomers.

4. Nitrile rubber according to claim 1, which has a value of Mooney viscosity (L(1+4 @100°C) from 10 to 150, preferably from 20 to 100 units Mooney.

5. Nitrile rubber according to one of claims 1 to 4, which has a glass transition temperature ranging from -70°C to +10°C, mostly in the range from -60°C to 0°.

6. Way to obtain the nitrile rubber according to claim 1 by emulsion polymerization of at least one α, β-unsaturated nitrile with a share constituting from 5 to 80 wt.%, and at least one conjugated diene with a share constituting from 20 to 95 wt.%, moreover, first obtained by polymerization containing a nitrile rubber latex is subjected to coagulation, and then the coagulated nitrile rubber is washed, characterized in that
(i) the emulsion polymerization is carried out in the presence of at least one alkylthiol, which contains 12 to 16 carbon atoms and at least three tertiary carbon atom, and a sulfur atom directly connected to one tertiary carbon atom, and
(ii) before coagulation pH value of the latex is, obtained by emulsion polymerization, set at the level of at least 6, coagulation of the latex is carried out using at least one magnesium salt, and the temperature of the latex to add at least one magnesium salt is set at the value of less than 45°C.

7. The method according to claim 6, and emulsion polymerization is carried out either periodically or continuously in a cascade reactor with stirring.

8. The method according to claim 6, and containing a nitrile rubber latex is added before or during coagulation of one or more inhibitors of aging.

9. The method according to claim 6, and for coagulation of the latex used magnesium chloride, magnesium sulphate and/or nitrate magnesium.

10. The method according to claim 6, in which the coagulation of the latex in addition to the use of at least one magnesium salt, preferably in the form of magnesium chloride, used optionally up to 5 wt.% one or more other salts of one or more other divalent metals in the calculation of the total number of all used for coagulation of salts.

11. The method according to claim 6, in which the coagulation of the latex in addition to the use of at least one magnesium salt is used to X wt.% salts of monovalent metal per total number of all used for coagulation salts, and X wt.% 50 wt.% net wt.% number one or is escolca other salts of one or more other divalent metals, if any.

12. The method according to claim 6, in which the coagulation of the latex is applied from 0.1 to 10 wt.%, preferably from 0.5 to 5 wt.%, at least one salt of magnesium per nitrile rubber.

13. The method according to claim 6, in which the coagulation of the latex is applied directly to such amounts, at least one salt of magnesium, which is necessary for complete coagulation of nitrile rubber.

14. The method according to claim 6, and at least one salt of magnesium, preferably magnesium chloride, used in the form of 0.1-35%by weight, mostly 0.5 to 30%by weight of the solution.

15. The method according to claim 6, and used for coagulation of the latex has a concentration of solids in the range of 1% to 40%, preferably within 5% - 35% and particularly preferably in the range of 15-30 wt.%.

16. The method according to claim 6, whereby the latex after adding at least one salt of magnesium is heated to a temperature of 100°C, preferably to a temperature in the range from 50 to 90°C.

17. The method according to claim 6, and for washing the coagulated nitrile rubber use deionized water or nedenominirovannyh water, preferably nedenominirovannyh water, if the coagulation of the latex, at least one magnesium salt no salt of calcium in the number of possible areas of up to 5 wt.% of all the salts.

18. The method according to one and p-17, moreover, leaching of coagulated nitrile rubber is carried out at a temperature in the range from 15 to 90°C., preferably at a temperature in the range of 45 to 70°C.

19. The use of nitrile rubber on one or more of claims 1 to 5 to obtain capable of vulcanizing the mixture.

20. Capable of curing a mixture containing at least one nitrile rubber according to one of claims 1 to 5, at least one crosslinking agent and, optionally, further additives target to the rubber.

21. The method of obtaining capable of vulcanization of the mixture according to claim 20, in which is mixed, at least one nitrile rubber according to one of claims 1 to 5, at least one crosslinking agent and optionally further additives target to the rubber.

22. A method of manufacturing a molded product based on the nitrile rubber according to one of claims 1 to 5, which is capable of vulcanizing the mixture according to claim 20, vulcanizer by molding, preferably using injection molding.

23. A molded product obtained by the method according to item 22.

24. Molded product according to item 23, characterized in that it is a gasket, cap, hose or the membrane, and in particular O-ring gasket, flat gasket rotary shaft seal, gasket, seal cap, protective dust cap, plug seal, t is Rosolini hose with and without the addition of PVC, hose oil cooler, air intake hose, air hose, servo steering or pump diaphragm.



 

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Polymer composition // 2476460

FIELD: chemistry.

SUBSTANCE: invention relates to composite polymer materials based on a butadiene-acrylonitrile elastomer, which are widely used in cable production and footwear industry. The composition contains a butadiene-acrylonitrile elastomer SKN-26, polyvinyl chloride, sulphur, captax, thiuram, stearine and technical carbon. Components are in the following ratio, pts.wt: butadiene-acrylonitrile elastomer SKN-26-80, polyvinyl chloride 20, sulphur 1.8, captax 1, thiuram 0.2, stearine 0.2, technical carbon 0.1-5.37. The polymer composition is modified by technical carbon nanoparticles with average particle size of 20-30 nm, the amount of which is determined using the following formula: c=0.1en, where n=0, 1, 2, 3, 4, e=2.7. The invention can be used in producing vulcanisates with high tensile strength, tear resistance, good dynamic properties and heat-ageing resistance.

EFFECT: articles made from the composition are characterised by such vital physical properties as strength, work of adhesion, permittivity, modulus of elasticity, mechanical and dielectric losses.

9 dwg, 1 tbl, 6 ex

Rubber mixture // 2476459

FIELD: chemistry.

SUBSTANCE: invention relates to rubber mixtures based on butadiene-acrylonitrile rubber. The rubber mixture contains the following, pts.wt: butadiene-acrylonitrile rubber SKN-26-95 and polyvinyl chloride 5, sulphur 1.9, captax 1.19, thiuram 0.24, stearine 0.95, technical carbon 0.1-5.37. The amount of technical carbon is calculated using the formula c=0.1en, where n= 0,1,2,3,4, e=2.7.

EFFECT: disclosed rubber mixture has high operational characteristics: strength, longevity, modulus of elasticity, loss-angle tangent.

4 dwg, 1 tbl

Nitrile rubber // 2470950

FIELD: chemistry.

SUBSTANCE: nitrile rubber contains repeating structural units of at least one α,β-unsaturated nitrile, at least one conjugated diene and optionally one or more further copolymerisable monomers and (i) has calcium content of at least 150 ppm with respect to nitrile rubber, and chlorine content of at least 40 ppm with respect to nitrile rubber, and (ii) contains terminal 2,2,4,6,6-pentamethylheptane-4-thio- and 2,4,4,6,6-pentamethylheptane-2-thio- and 2,3,4,6,6-pentamethylheptane-2-thio and 2,3,4,6,6-pentamethylheptane-3-thio- groups. Also disclosed is a method of producing nitrile rubber, use thereof, vulcanisable mixtures and method for production thereof, method of producing moulded articles and a moulded article.

EFFECT: obtaining rubber with special content of calcium and chlorine; the rubber has very high stability during storage.

21 cl, 6 tbl, 36 ex

FIELD: chemistry.

SUBSTANCE: composite layered rubberised fabric protective material based on butadiene-nitrile rubber with barrier layer is made three-layered and consisting of middle reinforcing layer, on both sides of which outer covering layers are located, and middle reinforcing layer is made in form of fabric from highly strong polyester fibre with thread of linear density 9-12 tex, with specific breaking load not lower than 610 mN/tex and number of coils 180-220 twists/m, or highly strong aramid fibre or their mixture, highly strong aramid thread with linear density 6.3-14.3 tex, specific breaking load not lower than 200 cN/tex and number of coils 90-130 twists/m being used in the fabric, and threads are used in form of two-component combined thread, whose first component in form of rod represents aramid and/or polyester complex thread or yarn, and second component of two-component combined thread in form of rod braid with number of coils 600-900 twists/m represents modified fire-proof viscose thread or yarn with linear density 10-30 tex, in aramid thread or yarn also used are polyparaphenylene terephthalamide, polymetaphenylene terephthalamide, copolyparaphenylene terephthalamide or copolyparaphenylene benzimidazole terephthalamide fibres. Outer covering layers are made from rubber composition, containing butadiene-nitrile rubber, accelerator of vulcanisation - zinc oxide and thiuram "D", sulphur, regulator of vulcanization rate - additionally zinc oxide, white soot and technical carbon, stearic acid, fire retardants - antimony trioxide, chloroparaffin and melamine cyanurate, pigment - titanium white, antioxidant - polymerised 1,2-dihydro-2,2,4-trimethyl quinoline. On the surface of material from one or two sides of outer covering layer applied is barrier film material from five successively located with respect to surface of outer covering layers, made with total thickness 18-36 mcm in the following succession: first layer from polyolefin, second layer from oriented polypropylene copolymer, third layer from polyvinyl alcohol, fourth layer from oriented polypropylene copolymer and fifth layer from polyolefin. Ratio of thicknesses of barrier layer layers is selected equal (0.18-0.22):(0.23-0.27):0.1:(0.23-0.27):(0.18-0.22). From both sides of third layer of barrier film material located are adhesive layers, made from copolymer of ethylene with vinyl alcohol and maleic anhydride, or from copolymer of ethylene with vinylacetate and maleic anhydride or from copolymer of ethylene with maleic anhydride.

EFFECT: invention makes it possible to provide reliable protection of human skin against aerosol and drop penetration of liquid chemical and harmful substances, preserving higher incombustibility and low surface density, and preserve high drapeability of material and its high tensile and tear strength.

10 cl, 6 ex

Nitrile rubber // 2479591

FIELD: chemistry.

SUBSTANCE: nitrile rubber contains repeating units of at least one α,β-unsaturated nitrile and at least one conjugated diene and has ionic index in the range of 7-26 ppm×mol/g. The nitrile rubber is obtained by emulsion polymerisation. The obtained latex, which contains nitrile rubber, is coagulated and the coagulated nitrile rubber is washed. Polymerisation is carried out in the presence of at least one alkylthiol. Before coagulation, the pH of the latex is set to at least 6, and coagulation is then carried out in the presence of at least one salt of a monovalent metal. The latex coagulation temperature ranges from 60 to 90°C and the washing temperature ranges from 50 to 90°C. The obtained nitrile rubber is used to obtain curable mixtures which contain said rubber and at least one cross-linking agent. The curable mixtures are cured by moulding to obtain moulded articles.

EFFECT: nitrile rubber has excellent curing rate and exceptional properties of cured products.

26 cl, 7 tbl, 13 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing fine polytetrafluoroethylene powder, as well as fine powder obtained using said method. The method of producing fine polytetrafluoroethylene powder involves emulsion polymerisation of tetrafluoroethylene in the presence of an aqueous medium, a fluorinated surfactant and a radical polymerisation initiator to obtain an aqueous emulsion of polytetrafluoroethylene and coagulation thereof in the presence of at least one apparent density-reducing compound selected from a group consisting of ammonia, an ammonium salt and urea, in amount ranging from 0.4 to 10 pts.wt per 100 pts.wt polytetrafluoroethylene. The fine polytetrafluoroethylene powder obtained using said method has standard specific mass from 2.140 to 2.180 and paste extrusion pressure from 10 to 25 MPa.

EFFECT: method of obtaining fine polytetrafluoroethylene powder which is capable of paste extrusion at low pressure using a simple method.

10 cl, 1 tbl, 10 ex

FIELD: chemistry.

SUBSTANCE: described is nitrile rubber which contains repeating units of at least one α,β-unsaturated nitrile and at least one conjugated diene and has chlorine content in the range of 4 to 25 ppm with respect to nitrile rubber. Described is a method of producing said nitrile rubber by emulsion polymerisation of at least one α,β-unsaturated nitrile, at least one conjugated diene and optionally one or more other copolymerisable monomers selected from a group comprising α,β-unsaturated mono- or dicarboxylic acids, esters and amides thereof, in the presence of a molecular weight regulator, with the latex which is obtained during polymerisation and contains nitrile rubber being subjected to coagulation and the coagulated nitrile rubber subsequently being washed, wherein (i) the latex obtained during emulsion polymerisation has a pH of at least 6 before the coagulation, (ii) coagulation of the latex is carried out using at least one salt of a mono-, di- or trivalent metal, which is optionally a chloride, as precipitant, (iii) coagulation of the latex is carried out in the presence of polyvinyl acetate, which is optionally partially or fully saponified, as coprecipitant, and (iv) coagulation of latex and/or treatment of the coagulated latex is carried out using water containing chloride ions under the condition that the salt of the mono-, di- or trivalent metal (ii) is not a chloride. A method of treating nitrile rubber obtained using the method described above is described, wherein nitrile rubber is subjected to (i) either a metathesis reaction only or (ii) a metathesis reaction and subsequent hydrogenation, or (iii) hydrogenation only, to obtain optionally hydrogenated nitrile rubber. Described is use of said nitrile rubber, optionally hydrogenated nitrile rubber, to obtain vulcanised mixtures, obtained by mixing at least one nitrile rubber or at least one optionally hydrogenated nitrile rubber, at least one cross-linking agent and optionally other additives. Described is a method of making moulded articles in form of a seal, a cap, a hose or a diaphragm, in particular an O-ring seal, a flat seal, a dynamic seal, a sealing sleeve, a sealing cap, an oil cooler hose, a hydraulic booster hose, an air conditioner hose, a thermal insulation hose, a diaphragm for hydro bearings or a diaphragm for a diaphragm pump, through vulcanisation during moulding, preferably via pressure casting of said vulcanised mixture.

EFFECT: nitrile rubber characterised by high stability during storage and high rate of vulcanisation are obtained, as well as with a preferable profile of properties, mainly with respect to contact of moulded articles based on such vulcanised rubber with metal structural components.

25 cl, 15 tbl, 5 dwg, 5 ex

FIELD: chemistry.

SUBSTANCE: described is nitrile rubber which contains repeating units of at least one α,β-unsaturated nitrile and at least one conjugated diene, and also contains magnesium ions in concentration of 100-180 ppm and calcium ions in concentration of 50-145 ppm, respectively, with respect to nitrile rubber. Described is a method of producing said nitrile rubber via emulsion polymerisation of at least one α,β-unsaturated nitrile, at least one conjugated diene and optionally one or more other copolymerisable monomers selected from a group comprising α,β-unsaturated mono- or dicarboxylic acids, esters and amides thereof, in the presence of at least one molecular weight regulator, with the latex which is obtained during polymerisation and contains nitrile rubber being subjected to coagulation and the coagulated nitrile rubber subsequently being washed, wherein (i) the latex obtained during emulsion polymerisation has a pH of at least 6 before the coagulation, (ii) coagulation of the latex is carried out using at least one magnesium salt, up to 40 wt % of which is optionally replaced with a calcium salt, as precipitant, (iii) the coprecipitant used during coagulation of latex is gelatine, (iv) temperature of latex before reacting with the coprecipitant (iii) is kept higher than 50°C, and then raised to 100°C, and (v) coagulation of latex and/or treatment of the coagulated latex is carried out using water containing calcium ions, under the condition that coagulation is carried out without a calcium salt as a precipitant. Treatment of nitrile rubber obtained using the method described above is described, wherein nitrile rubber is subjected to (i) either a metathesis reaction only or (ii) a metathesis reaction and subsequent hydrogenation, or (iii) hydrogenation only, to obtain optionally hydrogenated nitrile rubber. Described is use of said nitrile rubber, optionally hydrogenated nitrile rubber, to obtain vulcanised mixtures, obtained by mixing at least one nitrile rubber or at least one optionally hydrogenated nitrile rubber, at least one cross-linking agent and optionally other additives. Described is a method of making moulded articles, such as a seal, a cap, a hose or a diaphragm, in particular an O-ring seal, a flat seal, a dynamic seal, a sealing sleeve, a sealing cap, a cap for protection from dust, a plug seal, a thermal insulation hose (with or without a PVC additive), an oil cooler hose, an air hose, a servo control hose or a pump diaphragm, through vulcanisation during moulding, via pressure casting of said vulcanised mixture.

EFFECT: special nitrile rubber, characterised by high stability during storage and high rate of vulcanisation is obtained.

25 cl, 15 tbl, 38 ex

FIELD: chemistry.

SUBSTANCE: method of extracting butadiene-nitrile rubber from latex is carried out by feeding sodium sulphite or sodium bisulphite or sodium pyrosulphite in amount of 0.05-0.8 wt % per latex, into a stream of latex degassed beforehand, into which an antioxidant emulsion is also fed. Further, the stream of latex, containing sulphite, is directed into a coagulation apparatus into which aqueous sulphuric acid and an organic amine coagulant in form of a quaternary polymer ammonium salt are also simultaneously fed, said salt being selected from: polydimethyl diallyl ammonium chloride, a methacrylamide and dimethyl aminoethyl methacrylate hydrochloride copolymer, and polydiethyl aminoethyl methacrylate hydrochloride. The amount of the polymer ammonium salt varies from 0.2-0.5 wt %, per rubber, depending on content of leukanol content in latex in the range of 0.1-0.4 wt %, per rubber, at coagulation pH 3-6 and temperature 30-70°C.

EFFECT: invention improves environmental friendliness of the process, specifically reduces content of unreacted monomer - free acrylic acid nitrile, avoids excess synthetic coagulant and the amount of salt used for coagulation.

3 tbl, 7 ex

FIELD: chemistry.

SUBSTANCE: rubber is extracted from latex continuously by mixing latex with a coagulant. Consumption of coagulant is varied depending on the given turbidity value of serum (primary serum), which is maintained by the amount of coagulant fed. The given turbidity value of primary serum is adjusted depending on the turbidity of the serum released (secondary serum) towards the minimum consumption of coagulant to obtain minimum turbidity of the released serum.

EFFECT: method of controlling the coagulation process enables to reduce contamination of waste water through loss of partially coagulated latex with minimum consumption of coagulants.

2 dwg, 6 ex

FIELD: chemistry.

SUBSTANCE: present invention refers to emulsion rubber recovery from latex and can be used in chemical rubber industry. There is disclosed method of emulsion rubber recovery from latex through coagulation with using bivalent metal salts from magnesium chloride, magnesium sulphate, calcium chloride. Thereafter rubber crumb is separated from serum, it is followed with wringing and drying, differing that mixing latex and bivalent metal salt is preceded with pre-acidification of latex with diluted sulphuric acid concentrated 0.3-4% to pH 2.5-7.0 units. Within mixing range of acidulous latex and bivalent metal salt, concentration of the latter is kept within 0.05-0.8%, while produced rubber crumb is wrung out thus maintaining pH of wringing water within 2.5-6.9 units with sulphuric acid supplied to pre-acidification of latex.

EFFECT: making uniform rubber compatible with the requirements of related GOST and rubber TOR specifications in characteristics - mass fraction of organic acid soaps and mass fraction of organic acids, improved technological effectiveness and ecological compatibility of process.

2 cl, 1 tbl, 14 ex

FIELD: polymers, chemical technology.

SUBSTANCE: invention relates to the continuous method for preparing polytetrafluoroethylene (PTFE) or modified PTFE finely divided powders. The continuous method for preparing PTFE or modified PTFE finely divided powders involves the following steps: (a1) dilution of PTFE-latex of modified PTFE-latex prepared in polymerization in the dispersion-emulsion to the concentration from 5 to 25 wt.-% of PTFE or modified PTFE with possible filtration of the prepared diluted latex; (b1) molding latex with inert gas to the relative pressure with respect to atmosphere pressure in the range 3-40 kg/cm2 (0.3-4 MPa); (c1) addition of acid electrolyte solution to latex in the line-flow mixer at pH value 1-4; (d1) feeding the latex flow from the mixer through capillary tube under condition of turbulent current with the Reynolds number above 3000; (e1) gel prepared at step (d1) is coagulated onto granules at mechanical stirring with the specific power 1.5-10 kWt/m3 and stirring is maintained up to flotation of finely divided powder; (f1) below water is separated from the finely divided powder. PTFE of modified PTFE finely divided powders that can't be processed by thermal method prepared by abovementioned method show the following indices: apparent density is ≥ 470 g/l; average diameter of particles (D50) is above 200 mcm; distribution of particles by diameter determined as ratio between particles mass with diameter from 0.7 to 1.3 times with respect to average particles diameter and the total particles mass above 50%. Invention provides preparing powders without using the complex and expensive equipment, and powders possess the improved fluidity and show the apparent density and narrow distribution of particles by the diameter index.

EFFECT: improved preparing method.

9 cl, 1 tbl, 1 dwg, 6 ex

FIELD: polymer materials.

SUBSTANCE: invention is dealing, in particular, with thermally processed tetrafluoroethylene copolymers having predominantly spherical shape for at least 95 wt % of material. Median microsphere size lies within a range of 25 μm to 2 mm and bulk density between 0.5 and 1.1 g/cm3. Invention also concerns coagulation apparatus and microsphere preparation process.

EFFECT: enabled preparation microspheres of thermally processed tetrafluoroethylene copolymer characterized by specified morphology, controlled size, and improved fluidity.

18 cl, 2 tbl, 14 ex

The invention relates to the production of emulsion rubbers in powdered form and can be used in the synthetic rubber industry

Nitrile rubber // 2479591

FIELD: chemistry.

SUBSTANCE: nitrile rubber contains repeating units of at least one α,β-unsaturated nitrile and at least one conjugated diene and has ionic index in the range of 7-26 ppm×mol/g. The nitrile rubber is obtained by emulsion polymerisation. The obtained latex, which contains nitrile rubber, is coagulated and the coagulated nitrile rubber is washed. Polymerisation is carried out in the presence of at least one alkylthiol. Before coagulation, the pH of the latex is set to at least 6, and coagulation is then carried out in the presence of at least one salt of a monovalent metal. The latex coagulation temperature ranges from 60 to 90°C and the washing temperature ranges from 50 to 90°C. The obtained nitrile rubber is used to obtain curable mixtures which contain said rubber and at least one cross-linking agent. The curable mixtures are cured by moulding to obtain moulded articles.

EFFECT: nitrile rubber has excellent curing rate and exceptional properties of cured products.

26 cl, 7 tbl, 13 ex

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