Nitrile rubber

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

 

This invention relates to nitrile rubber, method thereof, mixtures, capable of curing 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 well known, see, for example, W. Hofmann, Rubber Chem Technol, 36 (1963) 1 and Ullmann''s Encyclopedia of Industrial Chemistry, 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 than for polyvalent metal ions, for example in the form of calcium chloride, magnesium chloride or aluminum sulfate (Kolloid-Z. 154, 154 (1957)). It is also known that the use of polyvalent metal ions leads to a more or less large inclusion of emulsifier in the product" (Houben-Weyl (1961), Methods der Org, Chemie, Makromolekulare Stoffe 1, str). 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 primary becoming the VA 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 2332096 known, h is about rubbers can stand out from their aqueous dispersions using methyl cellulose and water soluble salts of alkali metals, alkaline earth metal, 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 2425441 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 the residual water is removed. It also indicates that impurities in fact completely removed, as in the German patent application DE-OS 2332096, together with water in the separation of the coagulate, and all of the e remaining in a small amount remains completely washed out by flushing more water.

In the German patent application DE-OS 2751786 found that the selection and isolation rubbers from their aqueous dispersions is carried out with a low number (hydroxy)alkylaryl, if used 0,02-0,25% 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 an example Houben-Weyl (1961), Methods der Org. Chemie, Makromolekulare line 1, str/485. Rubber from the patent DE-OS 2751786 opposite have no signs of inhibition or degradation of, for example, when premature vulcanization and/iliri a complete cure.

None of the German application DE-OS 2332096, DE-OS 2425441 and DE-OS 2751786 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 3043688 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 3043688 which, when electrolytic coagulation of latex in addition to inorganic coagulate as an auxiliary means are used or derived 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 3043688 not given instructions as receiving and/or processing of the nitrile rubbers can be achieved fast vulcanization.

In U.S. patent US-A-4,920,176 described and confirmed using experimental data that the coagulation of nitriloacetic latexes using inorganic with the her as for example, sodium chloride or calcium chloride, is still very high in sodium, potassium and calcium, and as 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 when 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 not common assumptions, whether, and if so, in what way, by obtaining and processing nitrile rubbers to regulate the speed of vulcanization and the level of the module.

The aim of the European patent application EP-A-1369436 is to produce the nitrile rubbers of high purity. In particular, the content of the remaining emulsifiers greatly reduce the O. Also a 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-1369436 does not provide guidance for obtaining nitrile rubbers, which are fast curing and high modulus after vulcanization.

In the European patent applications EP-A-0692496, EP-A-0779301 and EP-A-0779300 in each case describes a nitrile rubber-based unsaturated nitrile and a conjugated diene. Common to all of nitrile rubbers is that they all have 10-60 wt.% unsaturated nitrile and a Mooney viscosity in PR the cases from 15-150 or according to the European application EP-A-0692496 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-0779300 indicates that the width "ΔAN (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-0692496 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 wt.%.

For nitrile rubber according to European patent EP-A-0779301 indicated that they have 3-20 wt.% fractions with low molecular weight (srednekislye molecular mass Mnis less than 35.000) the retrieval Method differs from those described in European application EP-A-0692496 fact, 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 wt.%.

In relation to the coagulation of the latex in all three European patent applications EP-A-0692496, EP-A-0779301 and EP-A-0779300 described that can be used any coagulants. As inorganic coagulants are mentioned and used calcium chloride and aluminium chloride. According to EP-A-0779301 and EP-A-0779300 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, amounting to a maximum of 3 ppm

In comparative example 6 of European patent application EP-A-779300 or comparative example 7 application EP-A-0779301 coagulation of the latex is carried out with a mixture of NaCl and CaCl2and CaCl2and what is in the large number and the mass ratio of NaCl and CaCl 2is 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-0692496, EP-A-0779300, as well as EP-A-0779301 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 combination 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 reach the I high productivity, as well as high-speed vulcanization during vulcanization with sulfur or with peroxides, in particular in the case of varieties NBR intended 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-0692496, EP-A-0779300 and EP-A-0779301 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 premature vulcanization is not satisfactory when processed by injection molding. Crucial for cost-effective processing is the establishment of a short time, qi is the fishing. 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 t10- time to reach 10% of the final vulcanization. Through the application used in European applications EP-A-0692496, EP-A-0779300 and EP-A-0779301 regulator 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-0692496 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-0692496 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 rubbers, and particularly the impact on the speed difference of a complete cure and premature vulcanizer and (t 90-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 so that the nitrile rubbers of different special cations.

The subject of this invention is a method for nitrile rubbers by emulsion polymerization of at least one α,β-unsaturated nitrile, at least one conjugated diene and optionally one or more further copolymerizing monomers, and 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) Alsina polymerization is conducted 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 is directly linked to one tertiary carbon atom,

(ii) before coagulation pH value of the latex obtained by emulsion polymerization, set at the level of at least 6 and then coagulated in the presence of at least one salt of a monovalent metal, and the coagulation of the valid presence of a maximum of 5 wt.% salts of divalent metals, based on the total number of all used for coagulation salts, and

(iii) as the coagulation of the latex, and further washed in each case the temperature of at least 50°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 7-26 ppm × g/mol,

moreover, c(Ca2+), c(Na+) and(K+- the concentration of ions of calcium, sodium and potassium in the nitrile rubber is indicated in ppm

Nitrile rubbers with ion indicator in these boundaries is going to high-speed vulcanization, characterized by a time difference of a complete cure and premature vulcanization (t90-t10), and 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-1369436 indicates the cations described for nitrile rubbers. Based on these data can be calculated ion indicators in accordance with the above equation (I). They are clearly outside the observed values for the nitrile rubber according to the invention: example 1 of European application EP-A-1369436 ion rate is 12,5 ppm ×mol/g, and in example 2 ion indicator, equal to 7.9 ppm ×mol/hodnoceno European application EP-A-1369436 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-1369436 there are no indications, 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 for nitrile rubbers is specified as the content of cations. On the basis of these data according to the above equation (I) can R scitebase ion indicators. If coagulation of the latex is used NaCl as described in the prior art US-A-4,920,176 receive ion rate lying in the range from 26.5 to a 44.2 ppm ×mol/g, and thus lies above the ion indicator nitrile rubber according to the invention. If according to USA-4,920,176 used as described polymer precipitating means according to the invention, receive ion rates of less than 3,8 ppm ×mol/g, and thus very clearly lie below the ion indicators nitrile rubbers of this invention. In the case of MgSO4the coagulation of the latex of technical solutions application US-A-4,920,176 obtained ion indicator 5,7 6,5 or ppm ×mol/g, that is, these values are clearly below the ion indicator according to the invention. When using calcium chloride as a precipitating means in accordance with the application US-A-4,920,176 obtained ion indicators from 63 to 135 ppm×mol/g, i.e. clearly above the ion indicator according to the invention.

In the examples of EP-A-0692496, EP-A-0779300, EP-A-0779301 for coagulation of the latex used calcium chloride, aluminum sulfate and magnesium sulfate. When using sodium chloride in comparative example 6 of European application EP-A-779300 or, respectively, in comparative example 7 of EP-A-0779301 used to 0.75 mass parts of calcium chloride on the mass part of sodium chloride. As with the actual content of the calcium ions included in the ion indicator with factor 3, for these experiments comes from the fact that the obtained nitrile rubbers have very high ion indicators (see US-A-4,920,176). Additionally, the description of the patent does not give the source of data on how and in what form the remaining set of cations in nitrile rubber affect the properties of the vulcanization.

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 concentrations of test solutions used in each case, the wavelengths of the linear region of the calibration (Century. 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 8-26 ppm×mol/g, particularly preferably in the field 10-26 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 a Smoot is ontril.

Thus, 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 complex ecrire 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, for example, a 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.

the particularly preferred 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, for example, polyethylene glycol(meth)acrylate, polypropylene bags-lepicol(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 wt.%, in the calculation 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 wt.%.

Additional monomers can find in quantities of from 0 to 40 wt.%, preferably is 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 wt.%.

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 wt.%.

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 wt.%.

Nitrile rubbers are the values of the Mooney viscosity (ML (1+4@100°C.)) of 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 nitrile rubbers and according to the finding, 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 AMA 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 water the salts of lithium, 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 oligomerization, while the degree of oligomer is Itachi 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 mass. parts, preferably 0.5 to 12.5 mass. parts, particularly preferably 1.0 to 10 mass. 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, on the feature of 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 are described in the filed on the same day the application of Lanxess Deutschland GmbH. Preferably 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) wsimages the procession 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 to 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-O-O - structural unit (peroxidase) or-N≡N is a 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 tertBUTYLPEROXY or phenothiazin.

Used in emulsion polymerization, the amount of water Le is it in the area of between 100 and 900 mass. parts, preferably in the region from 120 to 500 mass. parts, particularly preferably in the range from 150-400 masses. 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 to control the pH and 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 0-1 masses. parts, preferably 0-0,5 mass. 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 wt.% the total amount of initiator. Is also possible to further add the individual components of the initiating system.

If at is to obtain 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 154702, 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 inhibitors with the e 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.

For coagulation of the latex is used, at least one salt of a monovalent metal, preferably at least one salt of sodium and potassium.

Suitable are, for example, halides of monovalent metal, such as sodium chloride and potassium chloride, nitrates monovalent metal, such as sodium nitrate and potassium nitrate or sulphate monovalent metal, such as sodium sulfate and potassium sulfate.

Preferably applies salt of monovalent metallation with monovalent anion. Especially preferred is sodium chloride.

It is also possible to use mixtures of two or more salts of monovalent metals. Thus we can talk about how different the same salts of monovalent metals or various various salts of monovalent metals.

The coagulation of the latex valid the presence of a maximum of 5 wt.% salts of divalent metals in the calculation of the total number of all used for coagulation salts, preferably the maximum number of less than 5 wt.% and particularly preferably a maximum number of less than 3 wt.%.

The EU and as a salt of monovalent metal is applied only sodium chloride, in the method according to the invention, the calcium chloride may be contained in amounts up to 5 wt.%, preferably in quantities of less than 5 wt.% and especially preferably in amounts of less than 3 wt.%.

If coagulation NBR addition of sodium chloride is also used potassium chloride, the amount of potassium chloride is preferably X wt.%, moreover, the number of X wt.% is the difference of 40 wt.% less any existing wt.% the number of CaCl2.

The concentration of the salt solution is usually 3-30 wt.%. To obtain a salt solution can be used with either deionized water (in practice often shortened to "BO")or not deionized water, which contains calcium ions (in practice often shortened to "NV"). DW usually get from HB by processing ion exchange substance, or by means of distillation. If used for saline deionized water, was instrumental in the subsequent washing of the coagulated nitrile rubber to use wash water containing calcium ions. To obtain a salt solution during coagulation is used preferably water containing calcium ions, NV.

The right amount of salt or monovalent metal salts for coagulation of the latex is 1-200 masses. parts, preferably 5-50 mass. parts, particularly preferably 10-100 wt. parts per 100 mass. parts of nitrile rubber.

Coagulation of the latex can be achieved by adding a salt solution in latex, or alternatively, prior to adding latex and then adding the salt solution. Coagulation of the latex is carried out discretely or continuously. Preferred is a continuous coagulation, which is carried out by means of nozzles.

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, water-soluble polymers. They are non-ionic, anionic or cationic.

Examples of non-ionic polymer precipitating means are modified cellulose, such as hydroxyethylcellulose or methylcellulose, 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. Of these PR the products preferred by those have with a decrease in temperature decreases the solubility. Characteristic of cloud temperature range from 0 to 100°C., in particular 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.

The amount of polymer precipitating means is 0.01-5 wt. parts, preferably 0.05 to 2.5 mass. 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 Celes the imagery has a concentration of solids in the range of 1%-40%, preferably in the range of 5-35%, and particularly preferably in the range of 15-30 wt.%.

Coagulation of the latex is carried out at a temperature more than 50°C, preferably at a temperature in the range from 50 to 100°C. and especially preferably in the range from 55 to 90°C., highly preferably at a temperature in the range from 60 to 90°C. When carrying out the coagulation of the latex is also possible joint adding latex and solution at least one monovalent salt of a first metal at a temperature <50°C, it is crucial that the mixture is then latex salt is heated to a temperature exceeding 50°C.

The washing of the coagulated nitrile rubber:

After the coagulated nitrile rubber is usually presented in the form of so-called crumbs. Therefore, flushing coagulated nitrilebutadiene rubbers denoted as "rinse crumbs" (Krümelwäsche). 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 in the number 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 is.

Washing is carried out at a temperature more than 50°C, preferably at a temperature in the range from 50 to 90°C. and especially preferably in the range from 55 to 90°C.

The amount of wash water is 0.5-20 wt. parts, preferably 1-10 wt. parts and particularly preferably 1-5 wt. 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 wt.%. 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 preliminary removal of water. In the second stage, the remaining water is evaporated. As a preliminary removal of water and drying are preferably C is erevna. For mechanical preliminary removal of water suited / tube sheet screw presses, which water is squeezed sideways through the filter cracks or screws and 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 wt.%. 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 wt.%.

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

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

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, di-benzoyl 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 peroxymonosulfate, 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 to this the th 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 parts by weight per 100 parts by weight of the mixture, preferably in the range from 1.5 to 15 parts by weight per 100 parts by weight of the mixture, and particularly preferably in the range from 2 to 10 parts by weight per 100 parts by weight of the 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 vulcanization grey nitrile rubbers according to the invention may 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 is of ouchakov according to the invention can 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, are 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 dibutyldithiocarbamate (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 tetrasulfide 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, oxydiethylene-carbamyl-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 suitable additives, such as 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-mercaptobenzothiazol is, 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 parts by weight per 100 parts by weight of the mixture, preferably from 0.1 to 8 parts by weight per 100 parts by weight of the mixture, and particularly preferably 0.5 to 5 parts by weight per 100 parts by weight of the 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 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' di nitrazepan altimetery (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, VINYLTRIMETHOXYSILANE, vinylimidazoles, vinyltriethoxysilane, vinyltris(2-methoxy-ethoxy)silane, N-cyclohexyl-3-aminopropyltrimethoxysilane, 3-aminopropyl-trimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, dimethyldiethoxysilane, trimethylaluminium, isooctylmercaptoacetate, itact triethoxysilane, 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 parts by weight, per 100 parts by weight of 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 approximately 0 to 5 mass, 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 of the mold, 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 parts by weight, preferably 0.5 to 5 parts by weight per 100 parts by weight of nitrile rubber./p>

It is also possible reinforcement frame (fibers) of glass, according to the American patent application US-A-4,826,721 and reinforcement using 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 indicator 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 hose vozduhozabora is a, 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, the ruthenium or titanium, but may also be used 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 USA-3,700,637, DE-A-2539132, EP-A-0134023, DE-OS-3541689, DE-OS-3540918, EPA-0298386, DE-OS-3529252, DE-OS-3433392, US-A-4,464,515, 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-2539132 and European application EP-A-0471250.

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 is 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(triphenylphosphine)-rhodium(1)chloride, Tris(triphenylphosphine)-rhodium(III)-chloride, Tris(dimethyl sulfoxide)-rhodium(III)-chloride, and Tetra-KIS(triphenylphosphine)-rhodium-hydride of the formula (C6H5)3R)4RhH and the corresponding compounds in which the triphenylphosphine is actiono 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.%, in the calculation of the weight of the polymer.

It usually makes sense to use the catalyst in conjunction with socialization, which is a ligand of the formula R1mB, and R1, m and b have the 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. The co-catalyst is used preferably in an 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. In the calculations of the ones on 100 mass parts of hydrogenated nitrile rubber are applied respectively to 0.1 - 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 gidilounge 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 are caused, for example, on charcoal, 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 be used for the teaching of 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 (for a Description of this measurement technique in 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. For this we use a small rotor (S). "5 MS (120°C)" means the 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 53529. This method was to determine the characteristic time of vulcanization t10and 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.

And Getting NBR by emulsion polymerization

On the basis given in the following table 1 formulations manufactured NBR-latex. All the substances applied are indicated in the masses. parts per 100 mass. parts of the Monomeric mixture. The polymerization is carried out at a temperature of 17°C, duration of 13.5 hours to achieve the degree of polymerization of 80%.

Table 1
The substances appliedMass. part
Butadiene73
Acrylonitrile27
The total amount of water174+16+30
Erkantol®BXG1)to 3.67
Baykanol®PQ2)1,10
Potassium salt of fatty acid of coconut oil0,73
KON0,05
t-DDM3)0,24+0,24
Potassium peroxodisulfate4)0,39+0,19
Tris-(α-hydroxyethyl)-amine5)0,55
Sodium-dithionite6)1,19
The potassium hydroxide1,28
Vulkanox®KB7)1,25
1)Sol NAT the Oia mixture of mono and desulfonatronum naphthalenesulfonic acids, which contain isobutyleneisoprene residues (Erkantol®BXG)
2)the sodium salt of methylene-bis-naphthalenesulfonate (Baykanol®PQ; Lanxess Deutschland GmbH)
3)t-DDM: (tertiary dodecylmercaptan): a mixture of mercaptans from 12 carbon atoms to Lanxess Deutschland GmbH
4)catalogue number Aldrich: 21,622-4
5)catalogue number Aldrich: T5,830-0
6)catalogue number Aldrich:15,795-3
7)2,6-di-tert-butyl-p-basal; Lanxess Deutschland GmbH

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 sodium hydroxide and blew a stream of nitrogen. Then the reactor was added destabilized monomers (255,5 kg of butadiene 94.5 kg of Acrylonitrile) and the first installation of the regulator of the molecular weight of t-DDM (0,84 kg). The remaining amount of water (161 kg) were used to produce an aqueous solution of Tris-(α-hydroxyethyl)-amine, potassium of peroxodisulfate and sodium dithionite.

By adding an aqueous solution 1,365 kg of potassium peroxodisulfate (corresponding to 0.39 masses. parts according to table 1) and 1.95 kg of 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 the temperature Course 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 75%after 10.5 hours the polymerization was stopped by adding 4,165 kg sodium dithionite (1,19 masses. parts) and 4,48 kg of potassium hydroxide (1.28 masses. parts)dissolved in 105 kg of water (30 masses. parts). Unreacted monomers and other volatile component part was removed by distillation with steam.

Characteristics of the resulting latex are shown in table 2.

Table 2
Latex
Particle diameter (d50) [nm]360
Solid content [wt.%]18,9
PH8,9
The content of Acrylonitrile [wt.%]Before coagulation of the latex was added 1.25 masses. parts Vulkanox®KB per 100 mass. parts used in the polymerization of monomer mixture (see table 1). Vulkanox®KB was added to the latex as a 50%aqueous dispersion.

Water Vulkanox®-KB-dispersion was obtained in advance by using Ultraturrax at 95-98°C and the programme consisted of:

360 g of deionized water (DW)

40 g of alkyl phenol simple polyglycolether (emulsifier NP10 Lanxess Deutschland GmbH)

400 g of 2,6-di-tert-butyl-p-cresol (Vulkanox®KB Lanxess Deutschland GmbH).

In 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 of the latex salt concentration of the salt solutions used, the amount of salts in the calculation of the nitrile rubber, the temperature of the latex by adding salt, the temperature of the mixture of latex with salt after heating, the temperature when washing, as well as the duration of leaching are indicated in the following tables.

In the case of the examples according to the invention necessary for quantitative coagulation of a latex of a minimum quantity of sodium chloride were established in preliminary experiments, so in these examples was used in each case for quantitative coagulation of the latex with the e right amount of salt.

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 column 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 column 7.

For leaching rubber crumbs used a 100-liter capacity, equipped with 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 conducted experiments described here with a constant throughput of water 200 l/h For washing used depending on the sample or deionized and yet not containing calcium (DV) or water containing calcium (HB).

In most of the experiments 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 Rabaul the processes of leaching. Used when washing the rubber crumbs standard conditions (water temperature washing time, washing and so on) are provided in the following tables.

After washing the rubber crumb was removed using a sieve, and sealing screw previously obezvozhivani to a residual moisture content of 5-15 wt.% and dried with breaks in vacuumized drying Cabinet at 70°C to a residual moisture content of <1.5 wt.%.

The conditions applied for processing nitriloacetic latex collected in tables 3 and 4.

In table 5 are collected ion indicators to examples according to the invention and for comparative examples.

Solutions of NaCl used for coagulation of the latex, obtained in examples 1-4 with deionized water (DW). In example 5, the NaCl solution was obtained with the water containing calcium ions (HB).

In comparative example 9 to obtain the NaCl solution used for coagulation of the latex was applied to water containing calcium (HB). In the other, are shown in table 4 comparative examples to obtain the electrolyte solution used for coagulation of the latex, was used deionized water (DW).

Determination of ion indicators gives the following values.

Ion indicators of nitrile rubber of examples 1-5, 6-13
ExampleThe type of saltThe content of ionsIKZ
Ca [ppm]Mg [ppm]Na [ppm]K [ppm]
1NaCl620225701721,3
2NaCl565215751716,9
3NaCl45016201824,8
4NaCl435141051025,7
5 NaCl325191101219,3
V6NaCl54025951036,1
V7NaCl960346252744,1
V8NaCl570182301432,4
V9NaCl590222231134,3
V10CaCl21190617188,5
V11CaCl21290312196,2
V12CaCl21240261of 92.7
V13CaCl2123528192,3

To define the properties of unvulcanized rubber mixtures and vulcanizates rubber mixtures produced on the basis of nitrile rubbers in a laboratory mixer with a capacity of 1.5 liters, and separate components of a mixture are mixed in the specified table 6 order. All component parts of the mixture are listed in mass. parts per 100 mass. parts of nitrile rubber. Properties Wu is kunisato based on the nitrile rubber according to the invention or, respectively, from the comparative examples are combined in table 7.

Table 6
An integral part of mixtureThe amount in wt. parts
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, Lanxess Deutschland GmbH)0,9
Sulfur1,5

Table 7 shows that nitrile rubbers ion indicators according to the invention have a high rate of vulcanization (t90-t10), and after vulcanization, the high voltage value at 300% elongation. Using this comparison, the distinct advantages of the obtained nitrile rubber according to the invention.

1. Nitrile rubber, which contains recurring structural units of at least one α,β-unsaturated nitrile and, at measures which, one conjugated diene, and has an ion index IKZ General formula (I) in the field 7-26 ppm·mol/g

where(Ca2+), c(Na+) and c(K+- the concentration of ions of calcium, sodium and potassium in the nitrile rubber is indicated in ppm,
where the proportion of the α,β-unsaturated nitrile or amount of the α,β-unsaturated NITRILES is from 5 to 80 wt.% in the calculation on the entire polymer, and the proportion of the conjugated diene or the amount of conjugated dienes is from 20 to 95 wt.% in the calculation on the entire polymer, and the proportion of the monomers are added in each case to 100 wt.%.

2. Nitrile rubber according to claim 1, which has a value of ion indicator, lying in the field 8-26 ppm·mol/g, preferably in the field 10-26 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 (ML (1+4 @ 100°C.)) of 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°C.

6. Way to obtain the nitrile rubber according to any one of claims 1 to 5, in which first obtained by emulsion polymerization, with the holding nitrile rubber, the 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 is directly linked to one tertiary carbon atom, and
(ii) before coagulation pH value of the latex obtained by emulsion polymerization, set at the level of at least 6, and then coagulated in the presence of at least one salt of a monovalent metal, and the coagulation of the valid presence of a maximum of 5 wt.% salts of divalent metals, based on the total number of all used for coagulation salts, and
(iii) the coagulation of the latex is set to a temperature of from 60 to 90°C and subsequent washing of the temperature from 50 to 90°C.

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

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

9. The method according to claim 6, in which the coagulation of the latex is applied, at least one salt of sodium and potassium.

10. The method according to claim 6, inwhich for coagulation of the latex is applied, at least one halide monovalent metal, preferably sodium chloride and potassium chloride, at least one nitrate monovalent metal, preferably sodium nitrate and potassium nitrate, or at least one sulfate monovalent metal, preferably sodium sulfate and potassium sulfate.

11. The method according to claim 6, in which the coagulation of the latex is applied, at least one salt of monovalent metallation and one monovalent anion.

12. The method according to claim 6, in which the coagulation of the latex using a mixture of two or more salts of the monovalent metal, and we can talk about the different salts of the same monovalent metals or various various salts of monovalent metals.

13. The method according to claim 6, in which the coagulation of the latex valid the presence of a maximum of 5 wt.% salts of divalent metals in the calculation of the total number of all used for coagulation salts, preferably the maximum number of less than 3 wt.%.

14. The method according to claim 9, in which the coagulation of the latex in addition to sodium chloride is also used potassium chloride and the amount of potassium chloride is preferably X wt.%, moreover, the number of X wt.% is the difference of 40 wt.% net wt.% the quantity of calcium chloride, if one is available.

15. The method according to claim 6, in which the applied amounts of the salts or monovalent metal salts for coagulation of the latex is 1-200 parts by weight, preferably 5-150 parts by weight, particularly preferably 10-100 parts by weight per 100 parts by weight of nitrile rubber.

16. The method according to claim 6, in which is used to coagulate the latex has a concentration of solids in the range from 1% to 40%, preferably in the range from 5% to 35% and particularly preferably in the range from 15 to 30%.

17. The method according to claim 6, in which the latex and a solution of at least one salt of monovalent metal add together first at a temperature <50°C, and then the mixture of latex salt is heated to a temperature of from 60 to 90°C.

18. The method according to claim 6, in which for washing the coagulated rubber is used deionized water or nedenominirovannyh water, preferably nedenominirovannyh water, if the coagulation of the latex, at least one salt of a monovalent metal is missing is a salt of calcium in the number of possible areas of up to 5 wt.% of all the salts.

19. The method according to claim 6, in which the washing of the coagulated nitrile rubber is carried out at a temperature in the range from 50 to 90°C., preferably at a temperature in the range from 55 to 90°C.

20. The method according to one of PP-19, in which the obtained nitrile rubber is subjected to either (i) only the reaction of metathesis, or (ii) reactions metathesis and subsequent hydrogenation or (iii) only the hydrogenation.

21. The use of nitrile rubber is about one of claims 1 to 5 to obtain capable of vulcanization mixtures.

22. Capable of curing a mixture containing at least one nitrile rubber according to one of claims 1 to 5 and at least one crosslinking agent.

23. The method of obtaining capable of vulcanization of the mixture according to item 22, in which is mixed, at least one nitrile rubber according to one of claims 1 to 5 and at least one crosslinking agent.

24. 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 item 22 vulcanizer by molding, preferably using injection molding.

25. A molded product obtained by the method according to paragraph 24.

26. The moldings on A.25, 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, insulating 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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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

The invention relates to the selection of synthetic rubber from latex and can be used in the manufacture of synthetic rubbers

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

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