Molten polymer processing improving composite and use thereof
SUBSTANCE: composite additive contains particles of fibrous polytetrafluoroethylene and an effective amount of a fluorine-containing thermoplastic for preventing agglomeration of said particles of fibrous polytetrafluoroethylene.
EFFECT: improved processing of molten polymer, increased strength of basic polymer in molten mass.
10 cl, 2 tbl, 2 ex
1. The scope of the invention
The invention is a composite additive, which improves the processing of the polymer in the melt contains fibrous polytetrafluoroethylene (PTFE). In particular, the present invention presents a composition additive that improves the processing of the polymer in the melt, in which you can prevent the premature formation of fibers or agglomeration of the PTFE particles. In addition, the present invention describes methods of applying composite additives that improve the processing of the polymer in the melt during processing of the melt of the base polymer. In addition, the invention is a mixture of composite additives that improve the processing of the polymer in the melt or thermoplastic base polymer, and products obtained from these mixtures result of the extrusion process.
2. Background of the invention
The use of fluorine-containing polymer as a processing additive in the processing of thermoplastic base polymer, as a rule, do not contain fluoride base polymer, a well-known qualified specialists. As a rule, created on the basis of fluorine-containing polymer processing additives are used to improve processing of the melt of the base polymer. For example, fluoropolymer processing additives are used in order the increase the speed of extrusion of the base polymer, without causing the occurrence of defects on the surface of the extrudate or rupture of the melt.
Fluorine-containing polymers can be used to eliminate or reduce the manifestation of other problems encountered in the extrusion of thermoplastic polymers. These problems include, for example, the influx of polymer on the nozzle head (also called "rush head or leaking head"), the increase in back pressure in the extrusion process of drawing and excessive destruction or low strength of the polymer in the melt due to high temperature extrusion. These problems slow down the process of extrusion due to the fact that the process has to stop and clean the equipment, or due to the fact that the process must occur on lower speed.
It is known that some fluorocarbon processing additive partially weaken defects melt extrudable thermoplastic hydrocarbon polymers and allow extrusion faster and more efficiently. For example, in U.S. patent No. 3125547, issued in the name Blatz, first described the use of fluorocarbon polymer processing additives from processed from the melt hydrocarbon polymers, and fluorinated polymers are the homopolymers and copolymers of fluorinated olefins, in which the relation ATO the s of fluorine to carbon atoms is at least 1:2 and fluorocarbon polymers are indicators of melt flow, similar to those for hydrocarbon polymers.
In U.S. patent No. 4904735 (Chapman, Jr. et al.) describes fluorine-containing processing additive for use with high-melting polymer, which contains (1) a fluorocarbon copolymer, at a temperature of processing in the melt refractory polymer is, or in molten form, if is a crystalline substance, or above the point of vitrification, if it is amorphous, and (2)at least one homopolymer of tetrafluoroethylene or a copolymer of tetrafluoroethylene and at least one copolymerizing monomer and the molar ratio is at least 1:1, and which is solid at the temperature of processing in the melt refractory polymer.
Other ways of applying the processing composition of additives on the basis of fluorine-containing polymer disclosed in U.S. patent No. 5397897, U.S. patent No. 5064594, U.S. patent No. 5132368, U.S. patent No. 5464904, U.S. patent No. 5015693 and 4855013, U.S. patent No. 5710217 and U.S. patent No. 6277919 and WO 02/066544. Typically, these methods provide an easier extrusion of the base polymer, i.e. reduce the frequency of rupture of the melt and/or enable processing with greater speed.
Fluoropolymeric the processing additives are used to improve the mechanical properties of thermoplastic base polymer, to which they are added. For example, in the publication SER 822226 describes a mixture of PTFE particles with size less than 10 microns and particles of organic polymer. It is argued that this additive improves the processing properties of the molded and enhances the mechanical properties of thermoplastic polymer.
The use of fibrous PTFE as an additive to the molten thermoplastic base polymer can improve the melt strength and helps to obtain polymeric products with flame-retardant properties. Fire-retardant properties, usually acquired due to the fact that the product of the extruded polymer contains PTFE fiber, which give the polymer proteocephalidae properties.
At the same time the fibrous properties of PTFE create some problems when working with PTFE additives that improve the processability in the melt, therefore it is necessary to prevent agglomeration of the PTFE particles. In this regard, as a rule, with fibrous PTFE should be operated in such a way as to prevent the occurrence of shifts or, on the other hand, at low temperatures to avoid the formation of fibers and/or sintering to the moment when PTFE is added to the melt of the base polymer. This complicates the production process. It would be desirable to find more appropriate ways of preventing sintering of PTFE without stifling about what adowanie PTFE fibers in the extrusion process with the base polymer, to give an extruded product of the desired properties of increased strength in the melt and fire resistance.
3. Brief description of the invention
In one aspect of the present invention presents a composition additive that improves the processing of the polymer in the melt, intended for use as an additive in the process of melting the base polymer and characterized in that the composition of this composite additive that improves the processing of the polymer in the melt, is fibrous polytetrafluoroethylene and an effective amount of Vtorchermet necessary to prevent agglomeration of fibrous polytetrafluoroethylene ("PTFE"). The term "preventing agglomeration" means that the fibrous PTFE should not be subjected to sintering at all stages of the production process and processing of composite additives that improve processing in the melt, prior to adding to the processed melt of the base polymer, or that the particles must not be subjected to sintering in a degree which may significantly impair the ability of the composite additive to improve the strength of the melt or which can cause clumping of the resulting composition.
Found that the composite additive that improves the processing of the polymer in the melt, can improve processtemplate base polymer. In addition, the composite additive that improves the processing of the polymer in the melt, has a high adaptability, thanks to which you do not need to take special measures against the formation of fibers from the fibrous PTFE and/or sintering of the PTFE particles.
The term "base polymer"generally refers to a thermoplastic polymer, for which it is desirable to improve the strength of the melt and which composite additive that improves the processing of the polymer in the melt, is incompatible. Typically, the base polymer is a not containing fluorine polymer or a polymer with a degree of fluorination in which the ratio of fluorine atoms to carbon atoms does not exceed 1:1.
The term "Vtorchermet" refers to fluorine-containing polymer, i.e. a polymer with a fluorinated carbon chain and the ratio of fluorine atoms to carbon atoms in the carbon chain of at least 1:1, preferably at least 1,5:1. Fluorine-containing polymer is thermoplastic, i.e. it can melt when heated and can be processed in a suitable melting equipment, which is typically used for processing does not contain fluorine thermoplastic polymers. Fluorine-containing polymer has a distinct melting point and is usually semi-crystalline.
The term "fibrous PTFE is understood polytetrafluoroethylene, capable of forming fibers in the fusion and processing of the base polymer.
An additional aspect of the present invention relates to the mixture of base polymer and an effective amount of a composition of the additive, which improves the processing of the polymer in the melt, which, as mentioned above, increases the melt strength of the specified base polymer.
Another aspect of the invention is associated with extrusion of the above mixture and the product obtained in the extrusion process.
4. Detailed description of the invention
Fibrous PTFE, as a rule, is homopolymer tetrafluoroethylene (TPV), but can also be a TFE with another, for example, fluorine-containing monomer, such as chlorotrifluoroethylene (HCFA), perfluorinated vinyl ether, such as performatively vinyl ether (PMVE) or perfluorinated olefin, such as HEXAFLUOROPROPYLENE (HFP). The amount of fluorinated co monomer should be, however, low enough to obtain high molecular weight polymer, which is not processed from the melt. This usually means that the melt viscosity of the polymer should not exceed 1010PA·C. typically, the number of optional comonomers should not exceed 1%, in order PTFE conform to ISO 12086, defining requirements is I infusible PTFE. Such copolymers TPV known qualified as modified PTFE.
Fibrous PTFE, as a rule, consists of particles, the average size (average number) which is not more than 10 μm. Typically, the average particle size of the fibrous PTFE is in the range from 50 nm to 5 μm, for example from 100 nm to 1 μm. Practically, this range may be from 50 to 500 nm. One of the most convenient ways of fibrous PTFE is polymerization in aqueous dispersion medium.
Vtorchermet used in combination with the processing additive is generally semi-crystalline fluorine-containing polymer. Typically, this Vtorchermet should have a melting point that Vtorchermet was in the molten state at the process conditions of the processing in the melt used for the processing of the base polymer. Since many of the basic polymers, which are generally considered suitable for application in the framework of the present invention have a temperature of processing in the melt in the range from 150 to 320°C, forturnately with a melting point of from 100 to 310°C, generally regarded as desirable for use within the present invention. Preferably, the melting point of Vtorchermet was in di is the range between 100 and 250°C. Often Vtorchermet has a melting point not higher than 200°C.
Vtorchermet should be used in an amount effective to prevent agglomeration of the particles of fibrous PTFE. The effective amount can easily determine any qualified specialist in the result of routine experimentation. Typically, an effective amount of Vtorchermet is the number average of at least 10 weight % of the total weight of the fibrous PTFE. Generally, it is considered desirable to maximize the amount of PTFE in the composition of the additive, which improves the processing of the polymer in the melt, as a higher PTFE in the composition of the additive will make the latter more effective in achieving the desired properties when added to the melt of the base polymer, such as increased strength of the melt of the base polymer. The practical range of the quantitative content of Vtorchermet in the composition of the additive, which improves the processing of the polymer in the melt is at least 10 weight percent, for example, from 10 to 60 weight percent, more convenient from 12 to 50 weight percent, usually from 15 to 30 weight percent of the total weight of the fibrous PTFE.
Forturnately used in the composition of the additive, which improves the processing of the polymer in the melt, in luchot fluorine-containing polymers, which contain copolymerizable units derived from at least one fluorinated, ethylenediamino monomer, preferably from two or more monomers corresponding to the formula
where each group R is selected independently from the following substituents: H, F, Cl, an alkyl group ranging in length from 1 to 8 carbon atoms, an alkyl group ranging in length from 1 to 8 carbon atoms, a cyclic alkyl group ranging in length from 3 to 10 carbon atoms or performanceline group ranging in length from 1 to 8 carbon atoms. The R group preferably contains from 1 to 3 carbon atoms. In this monomer, each of the groups R may be the same as other R-groups. In an alternative embodiment, each of the groups R may be different from one or more of the other R-groups.
Fluorine-containing polymer may also contain a copolymer obtained by copolymerization of at least one monomer corresponding to the formula I, with at least one non-fluorinated, copolymerizate the co monomer corresponding to the formula:
where R1is selected independently from H, Cl, or an alkyl group ranging in length from 1 to 8 carbon atoms, a cyclic alkyl group ranging in length from 3 to 10 carbon atoms or aryl group ranging in length from 1 to 8 carbon atoms. R1preferably contains the t 1 to 3 carbon atoms.
As representative examples of suitable fluorinated monomers corresponding to the formula I, can be called, including, but not limited to, vinylidenefluoride, tetrafluoroethylene, HEXAFLUOROPROPYLENE, chlorotrifluoroethylene, 2-chlorination, dichlorofluorescein, 1,1-dichloromethylene and mixtures thereof. You can also use PERFLUORO-1,3-dioxole. PERFLUORO-1,3-dioxolane monomers and their copolymers are described in U.S. patent No. 4558141 (Squires).
As representative examples of suitable monomers corresponding to formula II include ethylene, propylene, etc.
As specific examples of fluorine-containing polymers can be called polyvinylidene fluoride, fluorine-containing polymers obtained by copolymerization of two or more different monomers corresponding to the formula I, and fluorine-containing polymers derived from one or more monomers corresponding to formula I, with one or more monomers corresponding to formula II. As examples of such polymers include compounds of copolymerizing blocks received from vinylidenefluoride (WDF) and hexaferrite (HFP); and derived from tetrafluoroethylene (TPV) and at least 5 weight %of at least one copolymerizable of co monomer, different from TPV. This last class of fluorine-containing polymers on what comprises polymers of copolymerizing blocks, received from TPV and HFP; polymers of copolymerizing blocks received from TPV, HFP and WDF; polymers of copolymerizing blocks received from TPV, HFP and a monomer corresponding to formula II; and polymers synthesized from copolymerizing blocks received from TPV and monomer corresponding to the formula II.
Vtorchermet can be obtained using any of the known methods of polymerization, although the polymerization in aqueous dispersion medium is usually considered preferable to obtain processed in the melt, thermoplastic fluorinated polymers.
Composite additive that improves the processing of the polymer in the melt, preferably obtained by mixing the aqueous dispersion system of the fibrous PTFE aqueous dispersion system Vtorchermet and deposition of the mixed dispersion, followed by drying the obtained product. Such a method is described, for example, in the publication WO 01/27197. This method has the advantage that in the process of production of composite additives it is possible to avoid the formation of PTFE fibers. However, it is also possible to obtain composite additive that improves the processing of the polymer in the melt by mixing dry PTFE and Vtorchermet. In the last case, you should pay special attention to the fact that the shearing force exerted is during the blending operation, did not cause the formation of PTFE fibers. In this regard, performed subsequently, the mixing should be carried out, generally at low temperatures, at which it is possible to avoid the formation of fibers. As soon as PTFE is mixed with an effective amount of Vtorchermet, the formation of PTFE fibers can be prevented, and in addition to improve the processing can be run in standard conditions. Composite additive that improves the processing of the polymer in the melt may contain additional additives needed to make the finished product the desired properties.
Composite additive that improves the processing of the polymer in the melt, is used in the process of melting of the base polymer. Among the base polymers suitable for use in connection with composite additive that improves the processing of the polymer in the melt, are polymers with which the composite additive that improves the processing of the polymer in the melt incompatible. Typically, the base polymer is a non-fluorinated or fluorinated marginally thermoplastic polymer.
A wide variety of polymers suitable for use as the base polymer in the framework of the present invention and including hydrocarbon and non-polymers. As examples of the approach is General basic polymers can be called, without any restrictions, polyamides, chlorinated polyethylene, polyimides, polyurethanes, polyolefins, polystyrenes, polyesters, polycarbonates, polyketone, polyureas, polyvinyl resins such as polyvinyl chloride, polyacrylates and polymethylacrylates.
A particularly suitable class of basic polymers are polyolefins. As representative examples of polyolefins suitable for use in the present invention include polyethylene, polypropylene, poly(1-butene), poly(3-methylbutan), poly(4-methylpentene) and copolymers of ethylene with such monomers as propylene, 1-butene, 1-hexene, 1-octene, 1-mission 4-methyl-1-penten and 1 octadecan.
Representative mixtures of polyolefins suitable for use in the present invention are mixtures of polyethylene and polypropylene, linear or branched low density polyethylenes, high density polyethylene, and polyethylene and copolymers of olefins containing copolymerizate monomers, some of which are described below, for example, copolymers of ethylene and acrylic acid; copolymers of ethylene and methyl acrylate; copolymers of ethylene and ethyl acrylate; copolymers of ethylene and vinyl acetate; copolymers of ethylene, acrylic acid and acrylate; copolymers of ethylene, acrylic acid and vinyl acetate.
The polyolefins can be obtained by homopolymeric the tion or copolymerization of olefins, as well as copolymers of one or more olefins and with the inclusion of up to about 30 weight percent or more, but preferably 20 weight percent or less of one or more monomers that are capable of copolymerisate with such olefins, for example, vinyl ester compounds such as vinyl acetate. These olefins can be characterized by the General structural formula CH2=CHR, where R is hydrogen or an alkyl radical, and, as a rule, this alkyl radical contains not more than 10 carbon atoms, preferably from one to six carbon atoms. Representatives of such olefins are ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-penten and 1-octene. Representatives of monomers that are capable of copolymerisate with olefins, are, in particular:vinyl ester monomers such as vinyl acetate, finalproject, vinylboronate, vinylchloride and vinylchloride; monomers of acrylic and alpha-alkylacrylate acids and their alkalemia esters, amides and NITRILES such as acrylic acid, methacrylic acid, etakrinova acid, methyl acrylate, acrylate, N,N-dimethylacrylamide, methacrylamide and Acrylonitrile; vinyl akrilovye monomers such as styrene, o-mitoxantron, p-mitoxantron, and vinylnaphthalene; vinyl and vinylidene-Galenia monomers, such as vinyl chloride vinylidenechloride and vinylidene; alkyl-EF is turning monomers of maleic and fumaric acids and their anhydrides, such as dimethyl-maleate, diethyl-maleate and maleic anhydride; vinyl alkyl ether monomers, such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether and 2-chloroethyl-vinyl ether; vinyl pyridine monomers; N-vinyl-carbasalate monomers and N-vinyl-pyrrolidinone monomers.
In a number of suitable base polymers also include metal salts of olefin copolymers or mixtures thereof, which contain a free group of carboxylic acids. As examples of metals that can be used to obtain the salts of these polymers with groups of carboxylic acids, can be called one-, two - and trivalent metals such as sodium, lithium, potassium, calcium, magnesium, aluminum, barium, zinc, zirconium, beryllium, iron, Nickel and cobalt.
In a number of suitable polymers also include mixtures of different thermoplastic polymers, and mixtures thereof, containing a variety of standard additives, such as antioxidants, light protection agents, fillers, antiadhesive and pigments.
The base polymers can be used in the form of powders, beads, pellets or any other extrudable form. The most preferred olefin polymers suitable for use in the present invention are hydrocarbon polymers, such as homopolymers of ethylene and propylene or SOP is the materials of ethylene and 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, propylene, vinyl acetate and methyl acrylate.
The mixture composition of the additive, which improves the processing in the melt, and the base polymer can be obtained by any of numerous known methods. For example, the base polymer and composite additive that improves the processing of the polymer in the melt, can be combined with any devices for mixing, which is usually used in the manufacture of plastics, including such as multi mill, a Bunbury mixer, or a mixing extruder in which the fluorinated polymer is evenly distributed around the base polymer. Composite additive that improves the processing of the polymer in the melt, and the base polymer can be used in the form of, for example, powder, small balls or granulated product. These components usually are mixed in dry form in the solid state as a particulate. The mixture composition of the additive, which improves the processing in the melt, and the base polymer can be used in the form of so-called masterbatches. This Royal blend, as a rule, the composition contains an additive that improves the processing of the polymer in the melt, in much larger quantities than required, as it will be diluted net base polymer in the processing of BA the new polymer in the melt. The number of composite additives that improve processing in the melt, in the so-called masterbatches, can vary from 2 to 20 weight percent relative to the weight of the base polymer, as a rule, this amount is from 5 to 10%. Alternatively, the composite additive that improves the processing of the polymer in the melt, can be added directly to the melt of the base polymer, when processing the last in the melt.
Composite additive that improves the processing of the polymer in the melt should be applied in amounts effective to produce the desired effect in the process of melting of the base polymer. Generally, this number should be sufficient to cause a measurable improvement in the strength of the melt of the base polymer. As a rule, in this context, an effective amount means that the composite additive that improves the processing of the polymer in the melt, is used in such amounts that the mixture of base polymer and composite additives that improve processing in the melt contains at least 500 ppm of fibrous PTFE from the total amount of base polymer. For example, an effective amount of a composition of the additive, which improves the processing in the melt mixed with the base polymer may be such that the amount of fibrous PTFE is nah is occurring in the range of from 500 to 50,000 ppm, easier from 800 to 20000 ppm, or from 1000 to 15,000 ppm of the total amount of base polymer.
The mixture of base polymer and composite additives that improve processing in the melt, as a rule, subjected to processing in the melt at temperatures from 180°C to 280°C, while the optimum operating temperature is selected depending on the melting point, melt viscosity and heat resistance brendirovannoy mixture. Different types of extruders that can be used for the extrusion of the compositions discussed in the framework of the present invention are described, for example, in the work Rauwendaal, C. "Polymer Extrusion", Hansen Publishers, p.23-48, 1986. The head design of the extruder may vary, depending on what the extrudate need to process. For example, a cylinder with a circular nozzle can be used for the extrusion of tubes used for hose fuel supply, such, for example, described in U.S. patent No. 5284184 (Noone et al.), the description of which is incorporated herein by reference.
Composite additive that improves the processing of the polymer in the melt, suitable for the extrusion of the base polymers, including, for example, extrusion of films, extrusion molded products, injection molding, extrusion of pipes, wires and cables, vacuum forming, molding foams and calender molding. Composite additive that improves the processing of polymer clay is in the melt, particularly well suited for the production of flame-retardant plastics and extruded products based on them.
To provide a more accurate understanding of the present invention further offers a few examples. These examples are chosen not as a comprehensive Union of all possible variants of realization of the present invention and do not provide for any limitations in the plan of implementation of the present invention.
All percentages are weight (mass), unless otherwise indicated.
The production of composite additives that improve the processing of the polymer in the melt,
Composite additive that improves the processing of the polymer in the melt, RM-1, obtained by mixing 100 ml of a 60% dispersion of PTFE (Dyneon™ TFX 5060) with 100 ml of a 30% dispersion of semi-crystalline thermoplastic fluorine-containing polymer containing repeating units derived from tetrafluoroethylene (TPV), hexaferrite (HFP) and vinylidenefluoride (WDF) (Dyneon™ THV 220D). Composite additive that improves the processing of the polymer in the melt, CM-1 was obtained by mixing 100 ml of a 60% dispersion of PTFE (Dyneon™ TFX 5060) with 100 ml of a 30% dispersion of amorphous fluorine-containing polymer HFP (38%) and WDF (62%), and the Mooney viscosity was 36. Comparative additive that improves the processing of the polymer in the melt-RM is allowed to receive from a 60% dispersion of PTFE (Dyneon™ TFX 5060).
The dispersed system was kept overnight at -20°C. After warming to room temperature the mixture was besieged. The precipitated mixture was filtered and was dried at 120°C during the night.
Example 1 and comparative examples C-1 to C-3
In example 1 and comparative example C-1 to 20 g of dry composition additives that improve processing in the melt, RM-1 and CM-1, respectively, was mixed with 180 g of polypropylene (PP, Escorene™ 5012 F2; MFI: 2,9; production company ExxonMobil). The mixture was mixed in the melt with the camera for mixing Haake Rheomix™, equipped with rotating blades at a temperature of 210°C for 8 minutes. The mixing process was monitored torque by using a rheometer Rheocord™ System 90. Conducted a comparative measurement of a mixture of 20 g of PTFE (CM-2) and 180 g of Escorene PP™ 5012 (comparative example C-2) and sample PP Escorene™ 5012 without additive composition for improving the processing in the melt (comparative example C-3). Balanced torque, registered in 8 minutes, are presented in table 1.
|Torque in mixtures of polypropylene (PP) and composite additives that improve the processing of the polymer in the melt|
|Example No.||Composition||Torque (Nm)|
|1||RR + RM-1||63|
|S-1||PP + SM-1||61|
|C-2||PP + SM-2||50|
As you can see from the above table, the composite additive that improves the processing of the polymer in the melt in accordance with the description in the present invention using Vtorchermet, increases the strength of the melt. In addition, the composite additive that improves the processing of the polymer in the melt, has the form of a free current of powder and easy to work with, as it shows no signs of premature formation of PTFE fibers. Composite additive that improves the processing of the polymer in the melt, CM-1, which was used with amorphous fusible thermoplastic fluorine-containing polymer also increased the strength of the melt, but had no forms free current of powder and it was also difficult to work when used as a composite additive that improves the processing in the melt, CM-2, which contain the Ala only fibrous PTFE.
Example 2 and comparative examples C-4 and C-5
In example 2, the polypropylene composition additives that improve the processing of the polymer in the melt was mixed as a dry mixture and compoundable using a twin-screw rasplavitsya Berstorff in the temperature range of 220-230°C and a melting temperature of 230°C.
Example 2 a mixture of Aristech PP 12MI and BP Amoco 12MIPP in the ratio of 50:50 containing 1% RM-1, was subjected to the injection molding. Comparative examples were described above PP without additive composition for improving the processing in the melt (4) and a mixture of PP with 1% PTFE (p-5).
Injection molding was performed using a machine Cincinnati Milacron-Fanuc Roboshot 11 OR model Robo110R-55. The temperature in the zone of injection molding was 230, 220, 220, 210°C (melting point: 216°C). The flow of the mixture took place in 2 stages: high feed speed of 90 mm/sec - up to 12 mm, and then 60 mm/sec, to the displacement of the mass at 9 mm. Other indicators apparatus for injection molding were: a pressure of 100 kg/cm2; RPM: 100; size of 63 mm respectively; the cooling time of 15 seconds; packet 450 for 3 seconds. Used form represented multiproto form TSM with elongated recesses 160 mm and 62 mm long, 125 mm curved stripe width of 12.5 to 3 mm, and three disks (diameter 62 mm, 25.5 mm and 8 mm). All cavities were open, and all the parts were with one entrance. The mold temperature was the mouth of Olena at 27°C.
Dynamic modulus G' was measured using an Ares Rheometer (now TA Instruments). Mold disk 2,55 cm 1.1 mm were analyzed at 240°C. in a nitrogen atmosphere between parallel plates with a diameter of 2.5 see Disks with samples were placed between preheated plates (240°C) and with a fixed clearance of 1.1 M. the sample was Then treated to the diameter of the plates. Clearance reduced to 1 mm, to form a meniscus. The test begins after equilibration for 100 seconds. The magnitude of the effort was set at 10%. The shear rate was varied from 0.1 rad/sec. up to 200 rad/sec. Rheological parameters (namely, the dynamic elastic modulus (G')), obtained for each formula, compared to a speed of 1 rad/sec.
The results are presented in table 2.
|Dynamic modulus of elasticity G'|
|Example No.||Composition||G' (MPa)|
|2||PP + 1% RM-1||4760|
|C-5||PP + 1% CM-2||4144|
These results show that the dynamic modulus of elasticity G' increased with the use of composite additives that improve the processing of the polymer in the melt and containing a mixture of PTFE with Vtorchermet. Received the best mechanical properties, although the fluorine-containing component in the additive that improves the processing of the polymer in the melt has been reduced.
1. Composite additive that improves the processing of the polymer in the melt, which improves the process of melting of the base polymer containing fibrous polytetrafluoroethylene and from 10 to 50% of Vtorchermet of the total weight of the fibrous polytetrafluoroethylene to prevent premature agglomeration of the specified fibrous polytetrafluoroethylene.
2. Composite additive that improves the processing of the polymer in the melt according to claim 1, characterized in that the fibrous polytetrafluoroethylene is in the form of particles of average size not exceeding 10 microns.
3. Composite additive that improves the processing of the polymer in the melt according to claim 1, characterized in that the polytetrafluoroethylene is infusible polytetrafluoroethylene.
4. Composite additive that improves the processing of the polymer in the melt according to claim 1, characterized in that the specified Vtorchermet has temperature is Lavinia in the range between 100 and 310°C.
5. Composite additive that improves the processing of the polymer in the melt according to claim 4, characterized in that the specified Vtorchermet has a melting point not higher than 250°C.
6. Composite additive that improves the processing of the polymer in the melt according to claim 1, characterized in that it further comprises a base polymer.
7. The method of processing in the melt of the base polymer, comprising the extrusion of the admixture of the base polymer and composite additives that improve the processing of the polymer in the melt according to claim 1 in an amount effective to improve the strength of the melt of the base polymer.
8. A mixture containing thermoplastic base polymer and composite additive that improves the processing of the polymer in the melt according to claim 1, which increases the melt strength of this base polymer.
9. The mixture according to claim 8, characterized in that said base polymer is not containing fluorine polymer.
10. The mixture according to claim 8, characterized in that specified does not contain fluoride polymer is a polyolefin.
11. The mixture according to claim 8, characterized in that the fibrous polytetrafluoroethylene is in the form of particles of average size not exceeding 10 microns.
12. The mixture according to claim 8, characterized in that the specified number of fibrous polytetrafluoroethylene is in the range between 500 and 50,000 million-1from the total amount the VA of the specified base polymer.
SUBSTANCE: invention relates to preparation of filled polymer antifriction compositions which used to make friction bearings of impellar blades of adjustable-blade turbines. The composition contains reinforcing fabric made from carbon fibre with average size of crystals on the basal plane of 3.0-6.0 nm and thickness of the packet of basal planes of 1.0-4.0 nm, thermosetting polymer binder based on chlorine-containing polyglycidyl arylene diamine resin and polytetrafluoroethylene inclusions with thickness of 2-4 mm and surface area of 4-9 mm2, total surface area of which makes up 10-30% of the surface area of the composition. The method of preparing the composition includes a step for adding a surface layer of polytetrafluoroethylene inclusions. Longitudinal and transverse 2-4 mm deep grooves are cut on a solid workpiece made from polytetrafluoroethylene. The surface layer of the workpiece with inclusions cut on a lathe is activated through treatment with a sodium naphthalene complex, joined through projections inside with carbon fabric which is saturated with chlorine-containing polyglycidyl arylene diamine resin. After combined pressure moulding, a surface sheet made from polytetrafluoroethylene is cut, leaving inclusions from polytetrafluoroethylene in the surface layer of the composition.
EFFECT: obtaining a composition which with low friction coefficient and low linear wear rate during prolonged use.
5 cl, 4 dwg, 1 tbl, 9 ex
SUBSTANCE: described is a method of preparing an aqueous dispersion of purified polytetrafluoroethylene, which involves passing a crude aqueous dispersion of polytetrafluoroethylene, containing 10-50 wt % fine particles of polytetrafluoroethylene having average diametre of 0.1-0.5 mcm, 0.05-1.0 wt % salt fluorine-containing carboxylic acid of formula (1) with respect to polytetrafluoroethylene, and 2-20 wt % non-ionic surfactant for formula (2) and/or formula (3) with respect to polytetrafluoroethylene, through a column filled with a weakly basic anion-exchange resin, in ascending direction with linear speed of 0.1-2 mm/s with contact time of 0.2-4 hours with reduction of content of the salt of the fluorine-containing carboxylic acid of formula (1): R1-COOX, where R1 is a C5-9 alkyl group having fluorine atoms instead of 90-100% hydrogen atoms (which can contain 1-2 oxygen atoms of an ether), and X is an ammonium ion; formula (2): R2-O-A-H, where R2 is a C8-18 alkyl group, A is a polyoxyalkylene chain consisting of 5-20 oxyethylene groups and 0-2 oxypropylene groups; formula (3): R3-C6H4-O-B-H, in which R3 is a C4-12 alkyl group, and B is a polyoxyalkylene chain consisting of 5-20 oxyethylene groups.
EFFECT: improved method of preparing an aqueous dispersion of purified polytetrafluoroethylene.
8 cl, 9 ex, 1 tbl
SUBSTANCE: there is disclosed tribotechnical polymer composition containing polytetrafluorethylene, synthetic magnesium spinel of specific surface 170-200 m2/g, and polymer filling. As such it contains fluorocarbon polymer 4MB in ratio as follows, wt %: polytetrafluorethylene - 93.0-97.0; fluorocarbon polymer 4MB - 2.0-5.0; magnesium spinel - 1.0-2.0.
EFFECT: improved composition.
1 cl, 1 ex, 1 tbl
SUBSTANCE: description is given of a fluoropolymer-containing dispersion system, in which particles of fluorine-containing polymer with average size from 10 to 400 nm are dispersed in water. The dispersion system contains 35-70 wt % solid substance. The dispersion system does not contain fluorinated surface active substance with molecular weight less than 1000 g/mol or contains the given fluorinated surface active substance with molecular weight less than 1000 g/mol in quantity of not more than 0.05 wt % of the total weight of solid substance in the dispersion system. The dispersion system also contains non-ionic non-fluorinated surface active substance or a mixture of different non-ionic non-fluorinated surface active substances and one or more non-fluorinated anionic surface active substances. The amount and nature of the non-ionic non-fluorinated surface active substances or the mixture of non-ionic non-fluorinated surface active substances is chosen in such a way that, the VTT value of the fluoropolymer-containing dispersion system is at least, 26°C and such that, fluoropolymer-containing dispersion system practically does not contain non-ionic surface active substances with aromatic groups. Description is also given of the method of producing fluoropolymer-containing dispersion system.
EFFECT: dispersion can be used for coating and impregnating a substrate.
11 cl, 19 ex, 1 tbl
FIELD: chemistry, processing technology.
SUBSTANCE: solidification mixture is described, consisting of: (a) fluoroplastic, solidificated mixture being optionally contain 1-70 wt % of fluoroplastic, and (b) fluoroelastomer resin; and fluoroplastic include nitrogen-containing vulcanisation center, where optionally monomer with nitrogen-containing vulcanisation center represents nitrile-containing vulcanisation centre monomer; where optionally nitrogen-containing vulcanisation centre is produced from either: (i) monomer with nitrogen-containing vulcanisation centre optionally chosen from group, which includes nitrile-containing vulcanisation centre monomers, amidine-containing vulcanisation center monomers and their salts, imidate-containing vulcanisation center monomers, and their combination; or (ii) nitrogen-containing agent of kinetic chain transfer; and elements obtained from fluorinated monomer, where fluorinated monomer is optionally chosen from group, which includes perfluorinated olefines, perfluorinated vinyl esters, and their combinations. Furthermore, hardened and molded piece is described obtained by such mixture solidification, and also the mixture is described, representing (a) latex, consisting of fluoroplastic particles, and (b) latex, consisting of fluoroelastomer resin particles.
EFFECT: described inventions have improved properties.
3 cl, 4 ex, 1 tbl
SUBSTANCE: invention pertains to compositions based on soluble fluoropolymers, meant for protecting metallic surfaces from action of water and aggressive media. The compositions can be used in the chemical industry and other industries when making equipment. Description is given of the anticorrosive composition is given. It consists of a soluble copolymer of tetrafluoroethylene with vinylidene fluoride, organic solvents - acetone, ethylacetate, cyclohexanone and amyl acetate, low molecular epoxide diane resin of the "ЭД-8" or "ЭД-10" type, amine hardening agent product of condensation of formaldehyde and phenol with ethylenediamine of the "АФ-2" type, diluting agent - ethyl cellosolve and an extra filler - graphite or molybdenum sulphide with proposed ratios of the components. Description of the method of coating metals is also given, in which the above mentioned composition is deposited on a non-greasy surface. The first and subsequent layers are dried under the same conditions at temperature of 15-25°C for a period of 20-30 minutes, and final coating is done at 120-200°C for 4-6 hours.
EFFECT: protection of metal surfaces from water and aggressive media.
3 cl, 5 ex, 2 tbl
SUBSTANCE: invention pertains to polymer composite materials for anti-frictional purposes, which can be used for making component parts of friction assemblies of machines and equipment. Description is given of the polymer composition, containing polytetrafluoroethylene and aluminium oxide with particle size of 9-11 nm as filler material, with the following ratio of components: nano-size aluminium oxide - 0.1-2.0 mass %, polytetrafluoroethylene constitutes the remaining percentage.
EFFECT: increased wear resistance, carrying capacity, reduction of coefficient of friction with retention of stress-strain properties of the composite material based on polytetrafluoroethylene.
1 cl, 1 ex, 1 tbl
FIELD: antifriction materials.
SUBSTANCE: invention relates to antifriction compositions based on soluble fluoropolymers that can be used to coat surfaces of piston rings, sealing rings, ring gaskets, collars, and other antifriction rubber parts used in friction units of machines in instrument engineering, chemical machinery construction, automobile industry, and aircraft industry. Antifriction composition described in invention comprises soluble tetrafluoroethylene/vinylidene fluoride copolymer, organic solvents: acetone, ethylacetate, cyclohexanone, and amyl acetate, low-molecular weight epoxy dian resin ED-8 or ED-10, amine hardener (product of condensation of formaldehyde and phenol with ethylenediamine AF-2), diluent (ethyl cellosolve), and, additionally, filler: graphite or molybdenum disulfide.
EFFECT: increased wear resistance and durability of rubber sealing members.
2 cl, 3 tbl, 5 ex
FIELD: polymer materials.
SUBSTANCE: invention is directed to composition used in chemical and petroleum processing industries, where high thermosetting properties of rubber compound composition are required, based on terpolymer and quaternary copolymer of terafluoroethylene and perfluoroalkyl vinyl ethers including cyano group and represented by structural formulas III, IV, and V, which composition comprises as vulcanization agent perfluorodiimidoylamidins of specified formula in amount 1-4 wt parts per 100 wt parts copolymer. Technical task of present invention was to work out composition imparting bright color to vulkanizates based thereon and, along with high physicochemical characteristics, manifests elevated heat resistance in strained state and resistance to concentrated nitric acid. The task is solved by using, as vulcanization agent, above-mentioned perfluorodiimidoylamidin of specified formula.
EFFECT: improved physicochemical characteristics and heat and chemical resistance.
2 cl, 3 tbl, 12 ex
FIELD: polymer materials.
SUBSTANCE: invention relates to polymer compositions based of fluoroplastic and fibrous fillers and can be used in manufacturing of slider bearings, sealing materials, tooth gears, and other structural parts of machines and mechanisms. Invention is directed to create polymer composition with improved physicochemical characteristics and provide polymer composition containing 83-95% of fluoroplastic and, as fibrous filler, 5-17% of ground organic paraaramid fiber (Rusar-S). Composition is distinguished by having compression strength higher by 22.5-39%, impact elasticity higher by 1.24-1.5 times, and wear lower by 1.2-1.6 times.
EFFECT: improved physicochemical characteristics of composition.
1 tbl, 6 ex
SUBSTANCE: thermoplastic polymer material is described, which contains an organic thermoplastic polymer and a complex additive for improving moulding in amount of 0.02-1 wt %. The complex additive used is a composition which contains polyester with melting temperature ranging from 35 to 120°C and molecular weight of 1000-10000 Da, and thickeners, selected from polymers with molecular weight ranging from 100000 to 20000000 Da which are soluble in polyesters, finely dispersed powders of oxides of silicon and titanium with particle size ranging from 1 to 1000 nm and phosphorus-containing organic compounds.
EFFECT: proposed thermoplastic polymer material allows for reducing energy consumption and moulding temperature during its processing, and reducing loss of polymer during moulding.
9 cl, 16 dwg, 16 ex
SUBSTANCE: invention relates to fire-resistant compositions which are used for making various products, for example in form of films, fibre, tape, moulding compositions, section materials or as binders for coating materials, adhesives or filler. This composition contains (a) polyolefin and (b) at least one compound of formula I: R4R3R2C-Z1-Z2-Z3(R2)rR3R4 (I).
EFFECT: use of non-halogenated compounds of general formula (I) in the composition as antipyrene for polyolefins and is an industrially and environmentally necessary alternative to halogenated antipyrene compounds, resulting in excellent combustion slowing down, excellent initial colouring, weak yellowing and self-extinction of such compositions.
20 cl, 4 ex, 2 tbl
SUBSTANCE: biodegradable granular polyolefin blend represents antimisting granules sized 2-8 mm of apparent bulk density 530-630 kg/m3, granule density less than 920-1300 kg/m3. Herewith melt flow index (MFI) of the parent polyolefin is MFI=2.5-25.0 g/10 minutes. Processing and relevant aid concentrate contains at least one biodegradable additive, thermostabilisers, antioxidants, lubricants, antistatic aids, pigments, fillers etc. The granular polymer blend is produced within a number of stages to ensure uniform distribution of all the aids in polyolefin. Four powder material flows are used. Three aid compositions are mixed with three parts of parent powder polyolefin in ratio 1:4, 1:3 and 1:2 respectively. Prepared concentrate mother stocks are supplied to the fourth combined mixer with residual part of polyolefin. If required, necessary liquid biodegradable additive. The blend is stirred and homogenised at 150-250°C.
EFFECT: underwater granulation and drying result in prepared antimisting and uncompressible sustained granular product characterised by good processing behaviour and performance attributes, easy-processed with the common equipment to make various products of controlled biodegradability.
3 cl, 5 tbl, 8 ex
FIELD: polymer production.
SUBSTANCE: invention relates to 1-butene copolymers containing up to 40 mol % ethylene or propylene derivatives. Copolymer of 1-butene with ethylene or propylene is described, which copolymer contains up to 40 mol % of ethylene and/or propylene units derivatives and manifests following properties: (a) product of copolymerization constants r1·r2 ≤ 2; (b) content of 1-butene units in the form of stereoregular pentads (mmmm) > 98%; and (c) lack of 4,1-inclusions of 1-butene units. Described are also: polymer compositions for manufacturing films, which contains above-indicated polymer; industrial product obtained from this copolymer; and a method for preparing such copolymer comprising 1-butene/ethylene (and/or propylene) copolymerization in presence of stereoregular catalyst containing (A) solid catalytic component including Ti compound and electron-donor compound selected from MgCl2-supported phthalates; (B) alkylaluminum compound; and (C) outer electron-donor compound of formula Ra5Rb6Si(OR7)c, wherein a and b are integers from 0 to 2, c is integer from 1 to 3, and sum (a+b+c)= 4, R5, R6, and R7 represent alkyl, cycloalkyl, or aryl radicals with 1-18 carbon atoms, optionally containing heteroatoms.
EFFECT: achieved specific balance between stereoregularity and distribution of comonomer, lack of 4,1-inclusions, and increased stretching strength.
26 cl, 8 tbl, 14 ex
FIELD: manufacture of building materials.
SUBSTANCE: material is made from principal composition containing polyethylene (mixtures of polyethylenes) and rubber crumb and, additionally, ethylene/vinyl acetate copolymer with vinyl acetate content 10-24% and characterized by melt flowability 10-18 g/10 min. Rubber crumb represents vulcanized waste with particle size 1.0-1.4 mm, which allows obtaining rubber-polymer material capable of being processed into granules and designed to be processed via jet molding into building materials such as large-size tile sheets.
EFFECT: enlarged choice of inexpensive building materials.
13 cl, 2 tbl, 6 ex
FIELD: polymer materials.
SUBSTANCE: invention relates to polymer material science and can be used to manufacture structural elements of various functional destinations. Composite thermoplastic polyolefin-based material contains filler and fire-retardant additive, the former being thermally treated silicate, namely product of treatment of naturally occurring silicates by heat stroke with gradient 800-1000°C, and the latter being halogen-containing oligomer selected from group including chloroparaffin and fluorine-containing oligomer ("Foleoks"), whereas above-mentioned polyolefin is selected from group including polypropylene, low-pressure polyethylene, high-pressure polyethylene, ethylene/vinyl acetate copolymer, and thermomechanically combined mixture of polyolefins with polyolefins, polyacetals, or styrene-containing plastics.
EFFECT: improved physico-mechanical characteristics of composite polyolefin-based material and increased resistance to burning and to action of negative temperatures.
FIELD: polymer materials.
SUBSTANCE: invention relates to compositions of polymer materials, which can be used to mold cutouts, fibers, tubes, films, and insulating coating on electric cable. Thermoplastic polymer material comprises polyolefin and additive for improving extrusion processing in amounts from 0.001 to 10 wt parts per 100 wt parts material. Additive is block copolymer based on diisocyanates with softening temperature below thermoplastic molding temperature.
EFFECT: improved appearance and mechanic characteristics and reduced price of manufactured products.
4 cl, 8 dwg, 1 tbl, 4 ex
FIELD: polymer materials.
SUBSTANCE: invention relates to stabilizer mixture used for stabilizing polyolefin against destruction initiated by visible light, heat, or oxidation and to thus stabilized polyolefin. Stabilizer mixture comprises spatially hindered amine compound and polymer containing polar residues, weight ratio of the two compounds being between 20:1 and 1:20, respectively, provided that (i) polymer cannot be the same compound as hindered amine compound and does not contain groups of formula (1) or (II): . Where G represents hydrogen atom or methyl and G1 and G2, independently of each other, each represents hydrogen atom or methyl or they together form =O; and (ii) polymer cannot contain acidic hydrogen atom.
EFFECT: considerable increased efficiency of stabilizer composition.
22 cl, 4 tbl, 4 ex
FIELD: technological processes.
SUBSTANCE: initial mold of item is shaped by forcing heated raw material through feeder valves through cavities of single- or multi-cavity nozzle. At that initial mold of item is simultaneously filled with internal filler. Feeder and clipper valves are closed for item isolation. Final molding of item is carried out by means of its rotation on liquid surface or in liquid medium, or along molding channel provided that even thermal settling of item is arranged.
EFFECT: lowering production wastes, power inputs and price of items.
10 cl, 10 dwg