Compositions and crosslinked products

Abstract

To provide compositions that are resistant to cracking even when compressed at high temperatures and that can yield cross-linked materials with excellent plasma resistance and excellent compression set properties.SOLUTION: Provided is a composition containing a perfluoroelastomer and polytetrafluoroethylene, where the melt viscosity of the polytetrafluoroethylene is from 1.0×103 to 7.0×106 poise, the melting point of the polytetrafluoroethylene is 322°C or higher, and the composition is obtained by co-coagulating the perfluoroelastomer and the polytetrafluoroethylene.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to compositions and crosslinked materials. [Background technology]

[0002] Conventionally, a technique has been known to improve the physical properties of perfluoroelastomers by adding fluororesin to them.

[0003] For example, Patent Document 1 describes a composition comprising fluoroplastic particles having an average particle size of less than 500 nm and an amorphous fluoropolymer.

[0004] Patent Document 2 describes a fluorine-based composition for sealing materials obtained by adding an inorganic acid solution to a mixture obtained by mixing a suspension of a fluorine-based elastic material and a suspension of a fluorine-based resin such that the mass mixing ratio of the fluorine-based elastic material and the fluorine-based resin is in the range of 95:5 to 5:95, and then co-coagulating the mixture. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Special Publication No. 2018-531316 [Patent Document 2] Japanese Patent Publication No. 2003-2681 [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of this disclosure is to provide a composition that can produce a crosslinked material that is resistant to cracking even when compressed at high temperatures and has excellent plasma resistance and excellent compression set characteristics. [Means for solving the problem]

[0007] According to a part of this disclosure, a composition comprising a perfluoroelastomer and polytetrafluoroethylene, wherein the melt viscosity of the polytetrafluoroethylene is 1.0 × 10 3 ~7.0×10 6 A composition is provided which is a poise, the melting point of the polytetrafluoroethylene is 322°C or higher, and which is obtained by co-coagulating the perfluoroelastomer and the polytetrafluoroethylene. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a composition that can obtain a crosslinked material that is resistant to cracking even when compressed at high temperatures and has excellent plasma resistance and excellent compression set characteristics. [Modes for carrying out the invention]

[0009] The following describes specific embodiments of this disclosure in detail, but this disclosure is not limited to the embodiments described below.

[0010] The compositions of this disclosure contain perfluoroelastomers and polytetrafluoroethylene (PTFE).

[0011] Conventional techniques for adding fluoroplastics or fluororesins to perfluoroelastomers have advantages over techniques for adding fillers such as inorganic particles to perfluoroelastomers, such as less particle generation. However, there is a need for a perfluoroelastomer composition that provides a crosslinked material with excellent plasma resistance, is less prone to cracking even when compressed at high temperatures for extended periods, and easily recovers its shape after being released from compression.

[0012] The inventors selected PTFE as the fluororesin, and further appropriately selected the melt viscosity and melting point of PTFE. As a method for preparing the composition, by selecting the method of co-precipitating a perfluoroelastomer and PTFE, it was found that the crosslinked product obtained by crosslinking such a composition is difficult to crack even when compressed at a high temperature and has excellent plasma resistance and excellent compression set characteristics, and thus the composition of the present disclosure was completed.

[0013] (PTFE) The melt viscosity of PTFE contained in the composition of the present disclosure is 1.0×10 3 ~7.0×10 6 Poise. The melt viscosity is preferably 1.0×10 4 Poise or more, more preferably 1.0×10 5 Poise or more, preferably 5.0×10 6 Poise or less, more preferably 3.0×10 6 Poise or less, and even more preferably 1.0×10 6 Poise or less.

[0014] By using PTFE with the melt viscosity within the above range, when the composition is crosslinked, a crosslinked product having excellent plasma resistance and excellent compression set characteristics can be obtained. If the melt viscosity of PTFE is too high, the compression set characteristics of the crosslinked product will not be sufficiently improved. For example, when the crosslinked product is compressed at a high temperature of about 300°C for a long time, problems such as the crosslinked product being crushed by compression or the shape of the crosslinked product being difficult to recover may occur. PTFE with too low melt viscosity may generate high-temperature volatile components, so it may not be suitable for use in crosslinked products used at high temperatures (for example, about 300°C).

[0015] PTFE having a melt viscosity within the above range has a low molecular weight, for example, PTFE with a number average molecular weight of 600,000 or less. "High molecular weight PTFE" with a number average molecular weight exceeding 600,000 exhibits the fibrillation characteristics unique to PTFE (see, for example, Japanese Patent Publication No. 10-147617). High molecular weight PTFE has a high melt viscosity and is non-melt processable. Preferably, the PTFE contained in the composition of this disclosure does not exhibit fibrillation characteristics to the extent that paste extrusion molding is possible. The melt viscosity and number average molecular weight of PTFE can be adjusted by adjusting the polymerization conditions of TFE when manufacturing PTFE or by irradiating PTFE with an electron beam.

[0016] The melt viscosity is measured in accordance with ASTM D 1238, using a flow tester (Shimadzu Corporation) and a 2φ-8L die. A 2g sample, preheated to 380°C for 5 minutes, is maintained at the above temperature under a load of 0.7 MPa. The number-average molecular weight can be calculated from the melt viscosity measured using the above method.

[0017] The melting point of the PTFE contained in the composition of this disclosure is 322°C or higher. Preferably, the melting point is 323°C or higher, more preferably 324°C or higher, even more preferably 325°C or higher, preferably 333°C or lower, more preferably 332°C or lower, and even more preferably 330°C or lower.

[0018] If the melting point of PTFE is too low, the compression set properties of the crosslinked material will not improve sufficiently. For example, if the crosslinked material is compressed at a high temperature of around 300°C for a long period of time, the PTFE will melt, making it difficult for the crosslinked material to recover its shape.

[0019] The melting point of PTFE can be determined using a differential scanning calorimeter X-DSC7000 (DSC) manufactured by Hitachi High-Tech Science Corporation. After pre-calibrating the temperature using standard samples of indium and lead, approximately 3 mg of PTFE that has not been heated above 300°C is placed in an aluminum pan and heated at a rate of 10°C per minute in the temperature range of 230-350°C under a nitrogen flow of 40 ml / min. Differential scanning calorimetry is performed, and the temperature corresponding to the minimum point of the melting curve in the above range can be determined as the melting point.

[0020] The specific surface area of ​​PTFE is preferably 0.5 to 20 m². 2 The value is / g. The specific surface area is measured using a surface analyzer (product name: BELSORP-miniII, manufactured by Microtrac-Bel) with a mixed gas of 30% nitrogen and 70% helium as the carrier gas, and liquid nitrogen for cooling, using the BET method.

[0021] The average primary particle size of PTFE is preferably 10 nm to 1000 μm, more preferably 100 nm or more, even more preferably 200 nm or more, more preferably 100 μm or less, even more preferably 10 μm or less, particularly preferably 1 μm or less, and particularly preferably 500 nm or less.

[0022] The average primary particle size was determined by first determining the correlation between the transmittance when 550 nm light was incident on a predetermined cell into which a PTFE aqueous dispersion adjusted to a solid content of 0.15 mass was injected, and the number-average primary particle size calculated by measuring the directional diameter using transmission electron microscopy, and then applying the transmittance measured for the obtained sample to the above correlation (calibration curve method).

[0023] PTFE may be a homopolymer of tetrafluoroethylene (TFE), or it may be a modified PTFE containing TFE units and modified monomer units copolymerizable with TFE. As for the PTFE, PTFE containing TFE units and modified monomer units copolymerizable with TFE is preferred because it further improves the compression set properties of the crosslinked material.

[0024] The content of modified monomer units in PTFE is 0 to 0.10 mol%, more preferably 0.02 mol% or more, even more preferably 0.05 mol% or more, and more preferably 0.09 mol% or less, relative to the total monomer units.

[0025] In this disclosure, "modified monomer unit" means a part of the molecular structure of PTFE that originates from the modified monomer, and "total monomer unit" means a part of the molecular structure of PTFE that originates from all monomers. The content of modified monomer units is a value measured by infrared spectroscopy or NMR (nuclear magnetic resonance).

[0026] The modified monomer in modified PTFE is not particularly limited as long as it can copolymerize with TFE, and examples include perfluoroolefins such as hexafluoropropylene (HFP); chlorofluoroolefins such as chlorotrifluoroethylene (CTFE); hydrogen-containing fluoroolefins such as trifluoroethylene and vinylidene fluoride (VDF); perfluorovinyl ether; perfluoroalkylethylene; and ethylene. Furthermore, one or more modified monomers may be used.

[0027] The above perfluorovinyl ether is not particularly limited, for example, general formula (I): CF2 = CF - ORf (I) Examples include perfluorounsaturated compounds represented by the formula (wherein Rf represents a perfluoroorganic group). In this specification, the term "perfluoroorganic group" means an organic group in which all hydrogen atoms bonded to a carbon atom are replaced with fluorine atoms. The perfluoroorganic group may have an ether oxygen.

[0028] Examples of the above-mentioned perfluorovinyl ether include perfluoro(alkyl vinyl ether) [PAVE], in which Rf in general formula (I) represents a perfluoroalkyl group having 1 to 10 carbon atoms. The number of carbon atoms in the perfluoroalkyl group is preferably 1 to 5.

[0029] Examples of perfluoroalkyl groups in the above-mentioned PAVE include perfluoromethyl, perfluoroethyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, and perfluorohexyl groups, but purple oromethyl vinyl ether [PMVE] in which the perfluoroalkyl group is a perfluoromethyl group, or purple oropropyl vinyl ether [PPVE] in which the perfluoroalkyl group is a perfluoropropyl group, are preferred.

[0030] The above perfluorovinyl ethers are further defined as those in general formula (I) where Rf is a perfluoro(alkoxyalkyl) group having 4 to 9 carbon atoms, and where Rf is in the following formula:

[0031] [ka] The base represented by (where m represents an integer from 0 to 4) is given by the following formula: CF3CF2CF2-(O-CF(CF3)-CF2) n - Examples include the base represented by (wherein n represents an integer from 1 to 4).

[0032] The perfluoroalkylethylene is not particularly limited and examples include perfluorobutylethylene (PFBE), perfluorohexylethylene, and perfluorooctylethylene.

[0033] In modified PTFE, the modified monomer is preferably at least one monomer selected from the group consisting of HFP, CTFE, VDF, perfluorovinyl ether, PFBE, and ethylene; more preferably at least one selected from the group consisting of HFP and perfluorovinyl ether; and even more preferably at least one selected from the group consisting of HFP, PMVE, and PPVE.

[0034] The PTFE content in the composition is preferably 1 to 100 parts by mass, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, particularly preferably 15 parts by mass or more, more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of perfluoroelastomer, in order to obtain a crosslinked product with even better plasma resistance and even better compression set characteristics. The PTFE content in the composition is even more preferably 55 parts by mass or less, and particularly preferably 50 parts by mass or less, in order to obtain a crosslinked product with even better compression set characteristics.

[0035] (Perfluoroelastomer) The compositions of this disclosure contain a perfluoroelastomer. Because the compositions of this disclosure contain a perfluoroelastomer as a fluororubber, when the compositions are crosslinked, a crosslinked product with excellent plasma resistance and excellent compression set properties can be obtained.

[0036] In this disclosure, a perfluoroelastomer is a fluoropolymer having a perfluoromonomer unit content of 90 mol% or more, preferably 91 mol% or more, relative to the total monomer units, having a glass transition temperature of 20°C or less, and a melting peak (ΔH) magnitude of 4.5 J / g or less, and further having a fluorine atom concentration of 71% by mass or more, preferably 71.5% by mass or more. In this disclosure, the concentration of fluorine atoms contained in the fluoropolymer is calculated from the type and content of each monomer constituting the fluoropolymer.

[0037] In this disclosure, a perfluoromonomer is a monomer that does not contain carbon-hydrogen atom bonds in its molecule. The perfluoromonomer may be a monomer in which some of the fluorine atoms bonded to the carbon atoms are replaced with chlorine atoms, or it may have nitrogen atoms, oxygen atoms, sulfur atoms, phosphorus atoms, boron atoms, or silicon atoms in addition to carbon atoms. Preferably, the perfluoromonomer is a monomer in which all hydrogen atoms are replaced with fluorine atoms. The perfluoromonomer does not contain monomers that provide crosslinking sites.

[0038] A monomer that provides crosslinking sites is a monomer (curing site monomer) that has crosslinkable groups that provide crosslinking sites to a fluoropolymer for crosslinking by a curing agent.

[0039] In this disclosure, the content of each monomer constituting the perfluoroelastomer can be calculated by appropriately combining NMR, FT-IR, elemental analysis, X-ray fluorescence analysis, and other known methods depending on the type of monomer.

[0040] As perfluoromonomers that provide perfluoromonomer units that constitute perfluoroelastomers, Tetrafluoroethylene (TFE), Hexafluoropropylene [HFP] General formula (13): CF2=CF-ORf 13 (In the formula, Rf 13 ) represents a perfluoroalkyl group having 1 to 8 carbon atoms. General formula (14): CF2=CFOCF2ORf 14 (In the formula, Rf 14 (where C1-C6 is a linear or branched perfluoroalkyl group, C5-C6 is a cyclic perfluoroalkyl group, or C2-C6 is a linear or branched perfluorooxyalkyl group containing 1-3 oxygen atoms) and, General formula (15): CF2=CFO(CF2CF(Y15 )O) m (CF2) n F (In the formula, Y 15 represents a fluorine atom or a trifluoromethyl group. m is an integer from 1 to 4. n is an integer from 1 to 4. ) Fluoromer represented by At least one selected from the group consisting of is preferred.

[0041] As the perfluoroelastomer, at least one selected from the group consisting of perfluoroelastomers containing TFE units, such as TFE / fluoromonomer copolymers represented by general formulas (13), (14), or (15), and fluoromonomers / monomer copolymers that provide crosslinking sites represented by general formulas (13), (14), or (15), is preferred.

[0042] The composition, in the case of a TFE / perfluoro(methyl vinyl ether) (PMVE) copolymer, is preferably 45-90 / 10-55 (mol%), more preferably 55-80 / 20-45, even more preferably 55-70 / 30-45, and most preferably 56-69.5 / 30.5-44.

[0043] In the case of monomer copolymers that provide TFE / PMVE / crosslinking sites, the preferred values ​​are 45-89.9 / 10-54.9 / 0.01-4 (mol%), more preferably 55-77.9 / 20-49.9 / 0.1-3.5, even more preferably 55-69.8 / 30-44.8 / 0.2-3, and most preferably 55.3-69.5 / 30.3-44.5 / 0.2-2.8.

[0044] In the case of TFE / fluoromonomer copolymers represented by general formulas (13), (14), or (15) with 4 to 12 carbon atoms, the ratio is preferably 50 to 90 / 10 to 50 (mol%), more preferably 60 to 88 / 12 to 40, even more preferably 65 to 85 / 15 to 35, and most preferably 66 to 84 / 16 to 34.

[0045] In the case of TFE / fluoromonomers represented by general formulas (13), (14), or (15) with 4 to 12 carbon atoms / monomer copolymers that give crosslinking sites, the preferred values ​​are 50 to 89.9 / 10 to 49.9 / 0.01 to 4 (mol%), more preferably 60 to 87.9 / 12 to 39.9 / 0.1 to 3.5, even more preferably 65 to 84.8 / 15 to 34.8 / 0.2 to 3, and most preferably 66 to 84.3 / 15.5 to 33.8 / 0.2 to 2.8. Outside of these compositional ranges, the rubber-elastic properties are lost, and the material tends to become closer in properties to that of a resin.

[0046] The perfluoroelastomer is preferably at least one selected from the group consisting of TFE / fluoromonomer represented by general formula (15) / monomer copolymer that provides a crosslinking site, TFE / fluoromonomer copolymer represented by general formula (15), TFE / fluoromonomer copolymer represented by general formula (13), and TFE / fluoromonomer / monomer copolymer that provides a crosslinking site.

[0047] Examples of the above-mentioned perfluoroelastomers include those described in International Publication No. 97 / 24381, Japanese Patent Publication No. 61-57324, Japanese Patent Publication No. 4-81608, Japanese Patent Publication No. 5-13961, etc.

[0048] A monomer that provides crosslinking sites is a monomer (curation site monomer) that has crosslinkable groups that provide crosslinking sites to a perfluoroelastomer for crosslinking by a crosslinking agent.

[0049] As monomers that provide crosslinking sites, General formula (16):CX 4 2=CX 5 R f 2 X 6 (In the formula, X 4 , X 5 Each of these is independently H, F, or an alkyl group having 1 to 5 carbon atoms, and R f2 X is a linear or branched alkylene group or oxyalkylene group which may have one or more ether-bonded oxygen atoms, may have an aromatic ring, and may have some or all of its hydrogen atoms substituted with fluorine atoms, 6 Examples of monomers represented by (wherein is an iodine atom, bromine atom, nitrile group, carboxyl group, alkoxycarbonyl group, hydroxyl group, vinyl group, azide group, sulfonyl azide group, carbonyl azide group, or alkyne group) include monomers represented by iodine atoms, bromine atoms, nitrile groups, carboxyl groups, alkoxycarbonyl groups, hydroxyl groups, vinyl groups, azide groups, sulfonyl azide groups, carbonyl azide groups, or alkyne groups). The alkyne group may be an ethynyl group.

[0050] Among the monomers that provide cross-linking sites, General formula (17):CX 16 2=CX 16 -Rf 16 CHR 16 X 17 (In the formula, X 16 These are, independently, a hydrogen atom, a fluorine atom, or CH3, Rf 16 is a fluoroalkylene group, a perfluoroalkylene group, a fluoro(poly)oxyalkylene group or a perfluoro(poly)oxyalkylene group, R 16 is a hydrogen atom or CH3, X 17 Fluoromers represented by an iodine atom or a bromine atom, General formula (18):CX 16 2=CX 16 -Rf 17 X 17 (In the formula, X 16 These are, independently, a hydrogen atom, a fluorine atom, or CH3, Rf 17 X is a fluoroalkylene group, a perfluoroalkylene group, a fluoro(poly)oxyalkylene group or a perfluoro(poly)oxyalkylene group, X 17 Fluoromers represented by an iodine atom or a bromine atom, General formula (19): CF2=CFO(CF2CF(CF3)O) m (CF2) n -X 18 (In the formula, m is an integer from 0 to 5, n is an integer from 1 to 3, X 18 Fluoromers represented by a cyano group, azide group, sulfonyl azide group, carbonyl azide group, carboxyl group, alkoxycarbonyl group, alkyne group, iodine atom, bromine atom, or -CH2I) General formula (20): CH2=CFCF2O(CF(CF3)CF2O) m (CF(CF3)) n -X 19 (In the formula, m is an integer from 0 to 5, n is an integer from 1 to 3, X 19 Fluoromers represented by a cyano group, carboxyl group, alkoxycarbonyl group, iodine atom, bromine atom, or -CH2OH, General formula (21):CR 20 2=CR 20 -Z-CR 20 =CR 20 2 (In the formula, R 20 Each is independently a hydrogen atom or a C1-C5 alkyl group. Z is a linear or branched alkylene group having an oxygen atom, having C1-C18, a C3-C18 cycloalkylene group, a C1-C10 alkylene group or oxyalkylene group that is at least partially fluorinated, or -(Q) p -CF2O-(CF2CF2O) m (CF2O) n -CF2-(Q) p - It is preferable that the monomer is at least one selected from the group consisting of monomers represented by (wherein Q is an alkylene group or an oxyalkylene group, p is 0 or 1, and m / n is 0.2 to 5) and has a molecular weight of 500 to 10000.

[0051] X 16 It is preferably a fluorine atom. Rf 16 and Rf 17 It is preferable that it is a perfluoroalkylene group having 1 to 5 carbon atoms. 16It is preferably a hydrogen atom. 18 It is preferable that the component is a cyano group, an alkoxycarbonyl group, an iodine atom, a bromine atom, or -CH2I. 19 The member is preferably a cyano group, an alkoxycarbonyl group, an iodine atom, a bromine atom, or -CH2OH.

[0052] The monomers that provide the crosslinking site are CF2=CFOCF2CF(CF3)OCF2CF2CN, CF2=CFOCF2CF(CF3)OCF2CF2COOH, CF2=CFOCF2CF(CF3)OCF2CF2CH2I, CF2=CFOCF2CF2CH2I, CH2=CFCF2OCF(CF3)CF2OCF(CF3)CN, CH2=CFCF2OCF(CF3)CF2OCF(CF3)COOH, and CH2=CFCF2OCF(CF3)CF2OCF(CF3)CH It is preferable that it be at least one selected from the group consisting of 2OH, CH2=CHCF2CF2I, CH2=CH(CF2)2CH=CH2, CH2=CH(CF2)6CH=CH2, CF2=CFO(CF2)3CN, and CF2=CFO(CF2)5CN, and more preferably at least one selected from the group consisting of CF2=CFOCF2CF(CF3)OCF2CF2CN, CF2=CFO(CF2)5CN, and CF2=CFOCF2CF2CH2I.

[0053] Perfluoroelastomers are preferable to have a glass transition temperature of -30°C or higher, more preferably -20°C or higher, and even more preferably -10°C or higher, due to their excellent compression set characteristics at high temperatures. Furthermore, due to their good cold resistance, the glass transition temperature is preferable to be 10°C or lower, more preferably 5°C or lower, and even more preferably 0°C or lower.

[0054] The above glass transition temperature can be determined by using a differential scanning calorimeter (Hitachi High-Tech Science Corporation, X-DSC7000) to heat 3 mg of the sample at 10°C / min to obtain a DSC curve, and then determining the temperature at the midpoint of the intersection of the extension of the baseline before and after the second-order transition of the DSC curve and the tangent line at the inflection point of the DSC curve.

[0055] In terms of good heat resistance, the perfluoroelastomer preferably has a Mooney viscosity ML(1+20) of 30 or higher at 170°C, more preferably 40 or higher, and even more preferably 50 or higher. In terms of good processability, it preferably has a viscosity of 100 or lower, more preferably 90 or lower, and even more preferably 80 or lower.

[0056] The above Mooney viscosity can be measured at 170°C using an ALPHA TECHNOLOGIES MV2000E Mooney viscometer in accordance with JIS K6300.

[0057] Perfluoroelastomers can be produced by conventional methods, but iodine compounds or bromine compounds can also be used as chain transfer agents because they allow for a narrow molecular weight distribution of the resulting polymers, easy control of molecular weight, and the introduction of iodine or bromine atoms at the terminals. Polymerization methods using iodine or bromine compounds include, for example, emulsion polymerization in an aqueous medium under pressurized conditions in the presence of an iodine or bromine compound, in a substantially oxygen-free environment (iodine transfer polymerization). Typical examples of iodine or bromine compounds used include, for example, those with the general formula: R 21 I x Br y (In the formula, x and y are integers from 0 to 2, and satisfy 1 ≤ x + y ≤ 2, R 21Examples of compounds are those represented by a saturated or unsaturated fluorohydrocarbon group or chlorofluorohydrocarbon group having 1 to 16 carbon atoms, or a hydrocarbon group having 1 to 3 carbon atoms (which may contain an oxygen atom). By using an iodine compound or a bromine compound, an iodine atom or a bromine atom is introduced into the polymer and functions as a crosslinking point.

[0058] Examples of iodine and bromine compounds include 1,3-diiodoperfluoropropane, 2-iodoperfluoropropane, 1,3-diiodo-2-chloroperfluoropropane, 1,4-diiodoperfluorobutane, 1,5-diiodo-2,4-dichloroperfluoropentane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1,12-diiodoperfluorododecane, 1,16-diiodoperfluorohexadecane, diiodomethane, 1,2-diiodoethane, 1,3-diiodo-n-propane, CF2Br2, BrCF2CF2Br, CF3CFBrCF2Br, CFClBr2, and BrCF Examples include 2CFClBr, CFBrClCFClBr, BrCF2CF2CF2Br, BrCF2CFBrOCF3, 1-bromo-2-iodoperfluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4-iodoperfluorobutane, 2-bromo-3-iodoperfluorobutane, 3-bromo-4-iodoperfluorobutene-1, 2-bromo-4-iodoperfluorobutene-1, monoiodomonobromo substituted derivatives of benzene, diiodomonobromo substituted derivatives, and (2-iodoethyl) and (2-bromoethyl) substituted derivatives, and these compounds may be used individually or in combination with each other.

[0059] Among these, 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane, and 2-iodoperfluoropropane are preferred in terms of polymerization reactivity, crosslinking reactivity, and availability.

[0060] The perfluoroelastomer preferably has cyano groups (-CN groups). Perfluoroelastomers having cyano groups (-CN groups) can be crosslinked by the cyano groups forming triazine rings through cyclization trimerization, or by forming imidazole rings using tetramine compounds as crosslinking agents, thereby imparting excellent compression set properties and heat resistance to the crosslinked material.

[0061] The perfluoroelastomer having the above-mentioned cyano group preferably has a cyano group (-CN group) at the main chain terminus and / or side chains.

[0062] Examples of perfluoroelastomers having cyano groups (-CN groups) at the main chain ends and / or side chains include the TFE / fluoromonomer represented by general formulas (13), (14), or (15) / monomer copolymers that provide crosslinking sites, in which the monomer providing the crosslinking sites is a monomer having cyano groups (-CN groups). In this case, the content of monomer units having cyano groups (-CN groups) may be 0.1 to 5 mol%, or 0.3 to 3 mol%, relative to the total amount of TFE units and fluoromonomer units represented by general formulas (13), (14), and (15), from the viewpoint of good crosslinking properties and heat resistance. More preferred compositions are as described above.

[0063] Furthermore, examples of monomers having a cyano group (-CN group) include, Formula:CY 1 2 = CY 1 (CF2) n -CN (In the formula, Y 1 (Each of these is either a hydrogen atom or a fluorine atom, and n is an integer between 1 and 8.) Formula: CF2=CFCF2Rf 8 -CN (In the formula, Rf 8 ha-(OCF2) n -or-(OCF(CF3)) n - where n is an integer between 0 and 5) Formula: CF2 = CFCF2(OCF(CF3)CF2) m(OCH2CF2CF2) n OCH2CF2-CN (where m is an integer from 0 to 5 and n is an integer from 0 to 5) Formula: CF2=CFCF2(OCH2CF2CF2) m ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Formula: CF2=CFO(CF2CF(CF3)O) m CF2CF(CF3)-CN (where m is an integer of 0 or more) Formula: CF2=CFOCF(CF3)CF2O(CF2) n -CN (where n is an integer of 1 or more) Formula: CF2=CFOCF2OCF2CF(CF3)OCF2-CN Formula: CF2=CFO(CF2)3CN Formula: CF2=CFO(CF2)5CN Examples include monomers represented by these formulas, and these can be used alone or in any combination.

[0064] Among these above,[[]] Formula: CF2=CF(OCF2CF(CF3)) m O(CF2) n -CN (where m is an integer from 0 to 5, and n is an integer from 1 to 8) The monomer represented by this formula is preferred, and CF2=CFOCF2CF(CF3)OCF2CF2CN is more preferred.

[0065] These perfluoroelastomers can be produced by conventional methods.

[0066] Specific examples of such perfluoroelastomers include fluororubbers described in International Publication No. 97 / 24381, Japanese Patent Publication No. 61-57324, Japanese Examined Patent Publication No. 4-81608, Japanese Examined Patent Publication No., 5-13961, etc.

[0067] (co - condensation) The compositions of this disclosure are obtained by co-coagulation of a perfluoroelastomer and PTFE. By preparing the compositions using the co-coagulation method, a crosslinked material with excellent plasma resistance and excellent compression set properties can be obtained when the compositions are crosslinked. If the compositions are prepared by methods other than co-coagulation, for example by dry blending, and the resulting compositions are crosslinked, the plasma resistance and compression set properties of the crosslinked material are not sufficiently improved. For example, problems may arise such as abrasion when the crosslinked material is irradiated with NF3 plasma, crushing of the crosslinked material due to compression when compressed at a high temperature of about 300°C for a long time, or difficulty in restoring the shape of the crosslinked material even after being released from compression.

[0068] When co-coagulating, the combination of perfluoroelastomer and PTFE is selected based on factors such as whether their coagulation properties are similar and whether they have polymer affinity, in accordance with the desired function.

[0069] Methods for co-coagulating perfluoroelastomer and PTFE include preparing an aqueous dispersion containing perfluoroelastomer and PTFE, and then co-coagulating the perfluoroelastomer and PTFE in the resulting aqueous dispersion.

[0070] Methods for preparing aqueous dispersions include mixing an aqueous dispersion containing a perfluoroelastomer with an aqueous dispersion containing PTFE, mixing perfluoroelastomer powder with an aqueous dispersion containing PTFE, and mixing PTFE powder with an aqueous dispersion containing a perfluoroelastomer.

[0071] When mixing an aqueous dispersion containing a perfluoroelastomer with an aqueous dispersion containing PTFE, the temperature of each aqueous dispersion is preferably 10°C or higher, more preferably 15°C or higher, even more preferably 20°C or higher, preferably 60°C or lower, and even more preferably 50°C or lower.

[0072] Methods for co-coagulating the perfluoroelastomer and PTFE in the aqueous dispersion obtained in this way include mixing the aqueous dispersion with a coagulant or freezing. As the coagulant, known coagulants such as acids can be used, for example, aluminum salts, calcium salts, or magnesium salts; as organic coagulants, ammonium acetate, ammonium carbonate, etc.; and as inorganic acid coagulants, hydrochloric acid, nitric acid, hydrofluoric acid, sulfuric acid, trifluoroacetic acid, etc. In particular, using an inorganic acid coagulant results in a clean composition with a low metal content, does not damage the crosslinking sites such as cyano groups of the perfluoroelastomer during coagulation, and yields a crosslinked product with a high crosslinking density when the composition is crosslinked. The resulting crosslinked product exhibits excellent plasma resistance and excellent compression set characteristics.

[0073] The temperature at which the aqueous dispersion and the coagulant are mixed is preferably 10°C or higher, more preferably 15°C or higher, even more preferably 20°C or higher, preferably 60°C or lower, and even more preferably 50°C or lower. The temperature at which the aqueous dispersion and the coagulant are mixed may be the temperature of the mixture obtained by mixing. When mixing an aqueous dispersion with an aqueous solution containing a coagulant, the temperature at which the aqueous dispersion and the coagulant are mixed can be adjusted by adjusting the temperatures of the aqueous dispersion and the aqueous solution.

[0074] The composition obtained by co-coagulation may be washed with water to remove small amounts of buffer solutions, salts, and other impurities present in the composition, and then the washed composition may be dried in a hot air oven or vacuum dryer. The drying temperature is preferably 40°C or higher, more preferably 50°C or higher, even more preferably 60°C or higher, preferably 200°C or lower, more preferably 150°C or lower, and even more preferably 100°C or lower.

[0075] The form of the composition obtained after co-coagulation is not particularly limited, but may be gum, crumb, powder, pellets, etc., and gum or crumb is preferred. Gum is a small granular mass made up of the composition, and crumb is an amorphous mass formed when the perfluoroelastomers in the composition cannot maintain their small granular shape as gum at room temperature and fuse together.

[0076] <Other ingredients> The compositions of this disclosure may contain components other than perfluoroelastomers and PTFE. Compositions containing other components may be prepared by adding the other components when co-coagulating perfluoroelastomers and PTFE, or by mixing the co-coagulated composition with the other components after co-coagulation of perfluoroelastomers and PTFE. Mixing can be carried out using conventional polymer processing machinery, such as open rolls, Banbury mixers, kneaders, and closed mixers.

[0077] Other ingredients include, for example, fillers.

[0078] Examples of fillers include imide-based fillers having an imide structure such as polyimide, polyamideimide, and polyetherimide; organic fillers made of engineering plastics such as polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyoxybenzoate; metal oxide fillers such as silicon dioxide, aluminum oxide, and yttrium oxide; metal carbides such as silicon carbide and aluminum carbide; metal nitride fillers such as silicon nitride and aluminum nitride; and inorganic fillers such as carbon black, aluminum fluoride, and carbon fluoride.

[0079] Among these, carbon black, aluminum oxide, silicon oxide, yttrium oxide, silicon carbide, silicon nitride, polyimide, and carbon fluoride are preferred in terms of their shielding effect against various plasmas.

[0080] Furthermore, the inorganic fillers and organic fillers mentioned above may be used individually or in combination of two or more types.

[0081] In fields where high purity and non-contamination are not particularly required, ordinary additives that are incorporated into the composition as needed, such as processing aids, plasticizers, and colorants, may be included, and one or more commonly used crosslinking agents or crosslinking aids different from those mentioned above may also be included.

[0082] The above composition may contain an organic basic compound. An example of an organic basic compound is a compound with the formula: CH3(CH2) 17 - NH2 ocdadecylamine; Formula:H2N-C(O)-(CH2) 11 -CH=CH-(CH2)7CH3 elkaamide; Formula: Oleamide of H2N-C(O)-(CH2)7-CH=CH-(CH2)7CH3; Formula: Hexamethylenediamine of the form H2N-(CH2)6-NH2 formula: [ka] Examples include 1,8-diazabicycloundec-7-ene (DBU).

[0083] (Crosslinking agents, etc.) The compositions of the present disclosure may further contain at least one selected from the group consisting of inorganic nitrides, organotin compounds, ammonia-generating compounds, and crosslinking agents. By containing these components, such as crosslinking agents, in the compositions of the present disclosure, crosslinked products can be easily obtained from the compositions of the present disclosure.

[0084] Inorganic nitrides are not particularly limited, but examples include silicon nitride (Si3N4), lithium nitride, titanium nitride, aluminum nitride, boron nitride, vanadium nitride, and zirconium nitride. Among these, silicon nitride is preferred because nano-sized particles can be supplied.

[0085] Examples of organotin compounds include tetraphenyltin and triphenyltin.

[0086] As for compounds that generate ammonia, compounds that generate ammonia at 40 to 330°C are preferred.

[0087] The ammonia-generating compound is preferably urea or its derivatives or ammonium salts, more preferably urea or ammonium salts, and even more preferably urea. The ammonium salt may be either an organic or inorganic ammonium salt. Furthermore, the ammonia-generating compound may be one that reacts with a small amount of water to generate ammonia.

[0088] Examples of urea derivatives include biurea, thiourea, urea hydrochloride, and biuret.

[0089] Examples of organic ammonium salts include ammonium salts of non-fluorinated carboxylic acids or sulfonic acids, such as ammonium benzoate, ammonium adipate, and ammonium phthalate.

[0090] Examples of inorganic ammonium salts include compounds described in Japanese Patent Publication No. 9-111081, such as ammonium sulfate, ammonium carbonate, ammonium nitrate, and ammonium phosphate.

[0091] Other ammonia-generating compounds include acetaldehyde ammonia, hexamethylenetetramine, formamidine, formamidine hydrochloride, formamidine acetate, t-butylcarbamate, benzylcarbamate, and phthalamide.

[0092] Examples of the above-mentioned crosslinking agents include those used in peroxide crosslinking, polyol crosslinking, polyamine crosslinking, triazine crosslinking, oxazole crosslinking, imidazole crosslinking, and thiazole crosslinking. When the perfluoroelastomer has a cyano group (-CN group), the crosslinking agent is preferably at least one selected from the group consisting of oxazole crosslinking agents, imidazole crosslinking agents, and thiazole crosslinking agents.

[0093] The crosslinking agent used in peroxide crosslinking can be any organic peroxide that can readily generate peroxy radicals in the presence of heat or an oxidation-reduction system. Specifically, examples include 1,1-bis(t-butylperoxy)-3,5,5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-butylperoxide (perbutyl D), t-butylcumylperoxide (perbutyl C), dicumylperoxide (permyl D, permyl D-40, permyl D-40MB(T)), α,α- Bis(t-butylperoxy)-p-diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane (perhexa25B, perhexa25B-40), 2,5-dimethyl-2,5-di(t-butylperoxy)-hexyn-3 (perhexyn25B, perhexyn25B-40), benzoyl peroxide, t-butylperoxybenzene, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane (perhexa25Z), t-butylperoxymaleic acid (t-butylMA), t-butyl Tyl peroxyisopropyl carbonate (Perbutyl I-75), methyl ethyl ketone peroxide (Permec D (DR), Permec H (HR, HY), Permec N (NR, NY), Permec S (SR), Permec F (FR), Permec G (GR, GY)), cyclohexanone peroxide (Perhexa H), acetylacetone peroxide (Percure AH, AL), 1,1-di(t-hexyl peroxy)-3,3,5-trimethylcyclohexane (Perhexa TMH), 1,1-di(t-hexyl Peroxy)cyclohexane (Perhexa HC), 1,1-di(t-butylperoxy)-2-methylcyclohexane (Perhexa MC), 1,1-di(t-butylperoxy)cyclohexane (Perhexa C-80(S), Perhexa C-75(EB), Perhexa C(C), Perhexa C-40, Perhexa C-40MB(S)), 2,2-di(t-butylperoxy)butane (Perhexa 22), 4,4-di-(t-butylperoxy)butyl pentanoate (Perhexa V, Perhexa V-40(F)), 2,2-di(4,4-di-(t-butylperoxy)cyclohexyl)propane (Pertetra A), p-menthane hydroperoxide (Permenta H), diisopropylbenzene hydroperoxide (Permil P), 1,1,3,3-tetramethylbutyl hydroperoxide (Perocta H), cumene hydroperoxide (Permil H-80), t-butyl hydroperoxide (Perbutyl H-69), di(2-t-butylperoxyisopropyl) Perfumes (Perbutyl P, Perbutyl P-40, Peroximon F-40, Perbutyl P-40MB(K)), Di-t-hexyl peroxide (Perhexyl D), Diisobutyryl peroxide (Perloyl IB), Di(3,5,5-trimethylhexanoyl) peroxide (Perloyl 355(S)), Dilauroyl peroxide (Perloyl L), Disuccinate peroxide (Perloyl SA), Di-(3-methylbenzoyl) Peroxide, benzoyl (3-methylbenzoyl) peroxide, and mixtures of dibenzoyl peroxide (Nipper BMT-K40, Nipper BMT-M), dibenzoyl peroxide (Nipper BW, Nipper BO, Nipper FF, Nipper BS, Nipper E, Nipper NS), di(4-methylbenzoyl) peroxide (Nipper PMB), di-n-propyl peroxydicarbonate (Perloyl NPP-50M) ), diisopropyl peroxydicarbonate (perloyl IPP-50, perloyl IPP-27), di(4-t-butylcyclohexyl) peroxydicarbonate (perloyl TCP), di(2-ethylhexyl) peroxydicarbonate (perloyl OPP), di-sec-butyl peroxydicarbonate (perloyl SBP), cumyl peroxyneodecanoate (perloyl ND, perloyl ND-50E), 1,1,3,3-Tetramethylbutyl peroxyneodecanoate (Perocta ND, Perocta ND-50E), t-Hexyl peroxyneodecanoate (Perhexyl ND, Perhexyl ND-50E), t-Butyl peroxyneodecanoate (Perbutyl ND, Perbutyl ND-50E), t-Butyl peroxyneoheptanoate (Perbutyl NHP), t-Hexyl peroxypivalate (Perhexyl PV, Perhexyl PV-50E), t -Butyl peroxypivalate (Perbutyl PV, Perbutyl PV-40E), 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate (Perocta O), 2,5-dimethyl-2,5-di(2-ethylhexanoyl peroxy)hexane (Perhexa 25 O), t-hexyl peroxy-2-ethylhexanoate (Perhexyl O, Percure HO(N)), t-butyl peroxy-2-ethylhexanoate (Perb Chill O, Percure O), t-hexyl peroxyisopropyl monocarbonate (Perhexyl I), t-butyl peroxy-3,5,5-trimethylhexanoate (Perbutyl 355), t-butyl peroxylaurate (Perbutyl L), t-butyl peroxy-2-ethylhexyl monocarbonate (Perbutyl E), t-hexyl peroxybenzoate (Perhexyl Z), t-butyl peroxyacetate (Perbutyl A), Examples include t-butylperoxy-3-methylbenzoate and a mixture of t-butylperoxybenzoate (Perbutyl ZT), t-butylperoxybenzoate (Perbutyl Z), t-butylperoxyallyl monocarbonate (Peromer AC), 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone (BTTB-25), and 2,3-dimethyl-2,3-diphenylbutane (Nofmer BC-90). Among these, dialkyl types are preferred. Furthermore, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane is particularly preferred. Generally, the type and amount of organic peroxide used are selected considering the amount of active -OO-, decomposition temperature, etc.

[0094] Furthermore, any crosslinking aid that can be used in this case is a compound that has reactive activity toward peroxy radicals and polymer radicals, and examples include polyfunctional compounds having functional groups such as -CH=CH2, -CH2CH=CH2, -CF=CF2, -C(CF3)=CF2, -C(CH3)=CF2, -CF=CF(CF3), -CF=CF(CH3), -C(C6H5)=CF2, -CF=CF(C6H5), -CH=CF2, -CF=CHF, -C(CF3)=CHF, -CF=CH(CF3), and -CH=CF(CF3) (where "C6H5" represents a phenyl group). Specifically, examples include triallyl cyanurate, triallyl isocyanurate (TAIC), triacryl formal, triallyl trimellitate, N,N'-n-phenylene bismaleimide, dipropagyl terephthalate, diallyl phthalate, tetraallyl terephthalate amide, triallyl phosphate, bismaleimide, fluorinated triallyl isocyanurate (1,3,5-tris(2,3,3-trifluoro-2-propenyl)-1,3,5-triazine 2,4,6-trione), tris(diallylamine)-S-triazine, triallyl phosphite, N,N-diallylcrylamide, and 1,6-divindodecafluorohexane.

[0095] Furthermore, as a crosslinking aid used together with the peroxide crosslinking agent, the general formula (31): [ka] (In the formula, there are six R 31 Each of these is an independently selected halogenated group having 1 to 5 carbon atoms, which may contain H, a halogen atom, or an ether bond, and Z 31 This can also include compounds represented by a linear or branched alkylene group, cycloalkylene group, or (per)fluoropolyoxyalkylene group having 1 to 18 carbon atoms, which optionally contains a heteroatom.

[0096] Compounds represented by general formula (31) include general formula (32): [ka] (In the formula, j is an integer from 2 to 10, preferably an integer from 4 to 8, and four R 32 Each of these is independently a compound represented by H, F, or an alkyl group or (per)fluoroalkyl group having 1 to 5 carbon atoms, general formula (33): [ka] (In the formula, Y 31 These are F, Cl, or H, respectively, and Y 32 These are F, Cl, H, or OR, each independently. 33 (Here, R 33 (which may be partially, substantially, or completely fluorinated or chlorinated, and is a branched or linear alkyl group) 33 This is a divalent group having 2 to 10 carbon atoms, optionally fluorinated, which may have an ether bond inserted, preferably Z 33 This is -(CF2) where m is an integer between 3 and 5. m - Compounds that are a group and represented by general formula (33) are preferably compounds represented by F2C=CF-O-(CF2)5-O-CF=CF2, general formula (34): [ka] (In the formula, Y 31 , Y 32 and Z 33 As stated above, R 34 Examples of compounds that can be independently represented by H, F, or an alkyl group or (per)fluoroalkyl group having 1 to 5 carbon atoms.

[0097] Crosslinking agents, or crosslinking aids used with peroxide crosslinking agents, include general formula (35): [ka]

[0098] (In the formula, R 35 ~R 37 Each of these is independently a hydrogen atom, a fluorine atom, an alkyl group, a fluorinated alkyl group, or a substituted or unsubstituted aryl group, R 35 ~R 37 At least one of them is a fluorine atom or a group containing a fluorine atom. m is an integer from 1 to 5. If m is 2 or greater, there are m R 35 ~R 37 These may be the same or different. The hydrogen atoms of the benzene ring may be substituted. We can also list compounds having at least one structure represented by ). When m is 1, it is preferable to have two or more of these structures.

[0099] Compounds having a structure represented by general formula (36) include general formula (36): [ka]

[0100] (In the formula, R 35 ~R 37 As stated above, p is an integer between 0 and 2, and n is an integer between 2 and 6. The compound represented by the general formula (37): [ka]

[0101] (In the formula, R 35 ~R 37 As stated above. R 38 m is a single bond, -SO2-, -O-, -S-, -CO-, heteroatom-containing group, substituted or unsubstituted alkylene group, substituted or unsubstituted cycloalkylene group, or substituted or unsubstituted arylene group. m is an integer from 1 to 5. Some or all of these groups may be fluorinated. Examples include compounds represented by ().

[0102] The heteroatom-containing group is not particularly limited as long as it is a divalent group containing a heteroatom. Examples of heteroatoms include oxygen, nitrogen, sulfur, boron, and phosphorus atoms.

[0103] Examples of crosslinking agents used for polyol crosslinking include polyhydric alcohol compounds such as bisphenol A and bisphenol AF.

[0104] Examples of crosslinking agents used for polyamine crosslinking include polyhydric amine compounds such as hexamethylenediamine carbamate, N,N'-disinnamyridene-1,6-hexanediamine, and 4,4'-bis(aminocyclohexyl)methanecarbamate.

[0105] Examples of crosslinking agents used for oxazole crosslinking, imidazole crosslinking, and thiazole crosslinking include, for example, general formula (41):

[0106] [ka]

[0107] (In the formula, R 41 -SO2-, -O-, -CO-, alkylene groups with 1 to 6 carbon atoms, perfluoroalkylene groups with 1 to 10 carbon atoms, or single bonds,

[0108] [ka]

[0109] The group is represented by R 42 and R 43 One side is -NH2 and the other is -NHR 44 , -NH2, -OH or -SH, R 44 is a hydrogen atom, a fluorine atom, or a monovalent organic group, preferably R 42 is -NH2 and R 43 ga-NHR 44Preferred specific examples of alkylene groups having 1 to 6 carbon atoms include methylene, ethylene, propylene, butylene, pentylene, and hexylene groups, while perfluoroalkylene groups having 1 to 10 carbon atoms include,

[0110] [ka]

[0111] These include the following. Note that these compounds are known as examples of bisdiaminophenyl compounds in Japanese Patent Publication No. 2-59177, Japanese Patent Publication No. 8-120146, etc.) Bisdiaminophenyl crosslinking agents, bisaminophenol crosslinking agents, bisaminothiophenol crosslinking agents, general formula (42):

[0112] [ka] (R 41 As mentioned above, R 45 Each of these is independently one of the following bases. [ka]

[0113] A bisamido-razone crosslinking agent represented by general formula (43):

[0114] [ka]

[0115] (In the formula, Rf 41 Amidorazone crosslinking agent represented by the general formula (44): (where is a perfluoroalkylene group having 1 to 10 carbon atoms), or general formula (44):

[0116] [ka]

[0117] Bisamido oxime crosslinking agents represented by the formula (where n is an integer from 1 to 10), general formula (45): HN=CR 45 R 46 (In the formula, R 45 These are H, NH2, and NHR 47 Selected from the group consisting of R 46 Ph, SO2H, NR 48 R 49 Selected from the group consisting of , 2-pyridine, and CH2CONH2, R 47 It is selected from the group consisting of Ph, NH2, and CN, and R 48 is selected from the group consisting of H, NHPh, CH2CONH2, linear alkyl groups having 1 to 8 carbon atoms, and branched alkyl groups having 1 to 8 carbon atoms, and R 49 Ph, COOC(CH3)3, NH2, CH2COOH, CSNH2, CNHNH3 + Cl - p-phenylCN, [ka] Examples include compounds represented by (selected from the group consisting of COPh). These bisaminophenol crosslinking agents, bisaminothiophenol crosslinking agents, or bisdiaminophenyl crosslinking agents have conventionally been used in crosslinking systems with cyano groups as crosslinking sites, but they also react with carboxyl groups and alkoxycarbonyl groups to form oxazole rings, thiazole rings, and imidazole rings, giving crosslinked products.

[0118] Furthermore, as a crosslinking agent, the general formula (46):X 41 -(CH2) n -R 50 -(CH2) m -X 41 (In the formula, X 41 These are, independently, an alkyne group, a nitrile group, or Y 41 P N3(Y 41 (where is SO, SO2, C6H4 or CO, and p is 0 or 1), n ​​and m are independent integers from 1 to 4, and R 50teeth, i) Fluoroalkylene group having 3 to 10 carbon atoms, ii) Fluoroalkoxylene groups having 3 to 10 carbon atoms, iii) Substituted arylene group, iv) Oligomers containing copolymer units of vinylidene fluoride and perfluoro(methyl vinyl ether), v) Oligomers containing copolymer units of vinylidene fluoride and hexafluoropropylene, vi) Oligomers containing copolymer units of tetrafluoroethylene and perfluoro(methyl vinyl ether), and vii) A crosslinking agent may also be cited, which is selected from the group consisting of oligomers containing copolymer units of tetrafluoroethylene and hydrocarbon olefins. This crosslinking agent is preferably used together with a perfluoroelastomer having a nitrile group, an azide group, a sulfonyl azide group, a carbonyl azide group, or an alkyne group. For example, the nitrile group of the perfluoroelastomer reacts with the azide group of the crosslinking agent to form a tetrazole ring and give a crosslinked product.

[0119] Particularly preferred crosslinking agents include compounds having multiple 3-amino-4-hydroxyphenyl groups or 3-amino-4-mercaptophenyl groups, or compounds of general formula (47):

[0120] [ka]

[0121] (In the formula, R 41 , R 42 and R 43Examples of compounds represented as above include, specifically, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (generic name: bis(aminophenol)AF), 2,2-bis(3-amino-4-mercaptophenyl)hexafluoropropane, tetraaminobenzene, bis-3,4-diaminophenylmethane, bis-3,4-diaminophenyl ether, 2,2-bis(3,4-diaminophenyl)hexafluoropropane, 2,2-bis[3-amino-4-(N-phenylamino)pheni Examples include 2,2-bis[3-amino-4-(N-methylamino)phenyl]hexafluoropropane, 2,2-bis[3-amino-4-(N-ethylamino)phenyl]hexafluoropropane, 2,2-bis[3-amino-4-(N-propylamino)phenyl]hexafluoropropane, 2,2-bis[3-amino-4-(N-perfluorophenylamino)phenyl]hexafluoropropane, and 2,2-bis[3-amino-4-(N-benzylamino)phenyl]hexafluoropropane.

[0122] Among these, 2,2-bis[3-amino-4-(N-phenylamino)phenyl]hexafluoropropane is preferred as a crosslinking agent due to its heat resistance, steam resistance, amine resistance, and good crosslinking properties.

[0123] The content of at least one selected from the group consisting of inorganic nitrides, organotin compounds, ammonia-generating compounds, and crosslinking agents is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.2 parts by mass or more, particularly preferably 0.3 parts by mass or more, preferably 10 parts by mass or less, more preferably 5.0 parts by mass or less, even more preferably 2.0 parts by mass or less, and particularly preferably 1.0 part by mass or less, per 100 parts by mass of perfluoroelastomer.

[0124] (Crosslinked product) The above composition can be suitably used as a molding material for obtaining a crosslinked product by crosslinking molding. A crosslinked product can be obtained by crosslinking the composition of this disclosure. The crosslinked product of this disclosure has excellent durability against NF3 plasma and exhibits low compression set even when used at high temperatures exceeding 300°C.

[0125] The crosslinked material of this disclosure has a compression set (300°C) of preferably 60% or less, and more preferably 55% or less, measured by leaving it at 300°C for 70 hours at a compressibility of 25%. The compression set (300°C) can be calculated by compressing the crosslinked material at a compressibility of 25%, leaving it at 300°C for 70 hours, then releasing the compression, leaving it at 23°C for 30 minutes, and then measuring the thickness of the crosslinked material before and after compression.

[0126] The crosslinked material of this disclosure is resistant to crushing even when compressed at high temperatures. According to this disclosure, a crosslinked material is provided that does not crack even when left at 300°C for 70 hours at a compressibility of 25%. Furthermore, according to this disclosure, a crosslinked material is provided that does not crack in the above test for measuring compression set (300°C) and for which compression set (300°C) can be measured (i.e., a crosslinked material having a value of compression set (300°C)).

[0127] The crosslinked material of this disclosure has a compression set (temperature change from 200°C to 70°C) measured by leaving it at 200°C for 70 hours at a compressibility of 25%, and then leaving it at 70°C for 24 hours, which is preferably 70% or less, and more preferably 65% ​​or less. The compression set (temperature change from 200°C to 70°C) can be calculated by compressing the crosslinked material at a compressibility of 25%, leaving it at 200°C for 70 hours, then leaving it at 70°C for 24 hours, then releasing the compression, leaving it at 23°C for 30 minutes, and then measuring the thickness of the crosslinked material before and after compression.

[0128] One method for obtaining a crosslinked product from a composition is to obtain a pre-molded body by molding the above composition as a molding material, and then to crosslink the pre-molded body. The method for obtaining the pre-molded body from the above composition can be a conventional method, and can be carried out by known methods such as heating and compressing in a mold, press-fitting into a heated mold, or extruding with an extruder. In the case of extruded products such as hoses and electric wires, a crosslinked product can be obtained by heating and crosslinking with steam or the like after extrusion.

[0129] The above crosslinking is called primary crosslinking, and can be carried out in the order of primary crosslinking followed by secondary crosslinking. Primary crosslinking is preferably carried out at 150-250°C for 5-120 minutes, and more preferably at 170-200°C for 5-60 minutes. Any known crosslinking method can be used, such as press crosslinking.

[0130] Secondary crosslinking is preferably carried out at 250-320°C for 2-48 hours, and more preferably at 280-310°C for 5-24 hours. Alternatively, secondary crosslinking may be carried out at 180-320°C for 2-24 hours, or at 190-310°C for 5-20 hours. Temperature variations may be introduced within this temperature range. Known crosslinking methods may be used as the crosslinking method, such as oven crosslinking. Crosslinking can be carried out, for example, in an air atmosphere or a nitrogen atmosphere.

[0131] The crosslinked material of this disclosure can be suitably used as a sealing material for semiconductor manufacturing equipment that requires particularly high heat resistance, especially for semiconductor manufacturing equipment that undergoes high-density plasma irradiation. Examples of the sealing material include O-rings, square rings, gaskets, packings, oil seals, bearing seals, lip seals, and the like. In addition, it can be used in various polymer products used in semiconductor manufacturing equipment, such as diaphragms, tubes, hoses, various rubber rolls, belts, etc. It can also be used as a coating material and lining material.

[0132] Furthermore, the semiconductor manufacturing equipment referred to in this disclosure is not limited to equipment specifically for manufacturing semiconductors, but broadly includes all manufacturing equipment used in the semiconductor field that requires a high degree of cleanliness, such as equipment for manufacturing liquid crystal panels and plasma panels. Examples include the following:

[0133] (1) Etching apparatus Dry etching equipment Plasma etching equipment Reactive ion etching apparatus Reactive ion beam etching apparatus Sputter etching apparatus Ion beam etching system Wet etching apparatus Ashing device (2) Cleaning equipment Dry etching cleaning equipment UV / O3 cleaning system Ion beam cleaning system Laser beam cleaning device Plasma cleaning device Gas etching cleaning equipment Extraction and washing device Soxhlet extraction and washing apparatus High-temperature, high-pressure extraction and washing apparatus Microwave extraction and washing device Supercritical fluid extraction and washing apparatus (3) Exposure apparatus Stepper Kota Developer (4) Polishing equipment CMP equipment (5) Film deposition equipment CVD equipment Sputtering device (6) Diffusion and ion implantation apparatus Oxidation diffusion device Ion implantation device

[0134] The crosslinked material of this disclosure exhibits excellent performance as a sealing material for, for example, CVD equipment, plasma etching equipment, reactive ion etching equipment, ashing equipment, or excimer laser exposure equipment.

[0135] Although embodiments have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of the claims.

[0136] <1> According to the first aspect of this disclosure, A composition containing a perfluoroelastomer and polytetrafluoroethylene, wherein the melt viscosity of the polytetrafluoroethylene is 1.0 × 10⁻⁶ 3 ~7.0×10 6 A composition is provided which is a poise, the melting point of the polytetrafluoroethylene is 322°C or higher, and which is obtained by co-coagulating the perfluoroelastomer and the polytetrafluoroethylene. <2> According to the second aspect of this disclosure, A composition is provided in which the perfluoroelastomer has a cyano group, according to a first aspect. <3> According to the third aspect of this disclosure, A composition is provided in which the polytetrafluoroethylene optionally contains modified monomer units, wherein the content of the modified monomer units is 0 to 0.10 mol% relative to the total monomer units, according to a first or second viewpoint. <4> According to the fourth aspect of this disclosure, A composition is provided in which the polytetrafluoroethylene contains modified monomer units, and the content of the modified monomer units is 0.02 to 0.10 mol% with respect to the total monomer units, according to a first or second viewpoint. <5> According to the fifth aspect of this disclosure, A composition is provided in which the modified monomer unit is at least one selected from the group consisting of hexafluoropropylene units and perfluorovinyl ether units. <6> According to the sixth aspect of this disclosure, A composition is provided according to any one of the first to fifth viewpoints, wherein the average primary particle size of the polytetrafluoroethylene is 200 nm or more. <7> According to the seventh aspect of this disclosure, A composition is provided according to any one of the first to sixth views, wherein the polytetrafluoroethylene content is 1 to 100 parts by mass per 100 parts by mass of the perfluoroelastomer. <8> According to the eighth aspect of this disclosure, A composition according to any of the first to seventh viewpoints is provided, obtained by preparing an aqueous dispersion containing the perfluoroelastomer and the polytetrafluoroethylene, and co-coagulating the perfluoroelastomer and the polytetrafluoroethylene in the obtained aqueous dispersion using an acid. <9> According to the ninth aspect of this disclosure, Furthermore, a composition according to any of the first to eighth viewpoints is provided, containing at least one selected from the group consisting of inorganic nitrides, organotin compounds, ammonia-generating compounds, and crosslinking agents. <10> According to the tenth aspect of this disclosure, A crosslinked product is provided, obtained by crosslinking a composition according to any of the first to ninth aspects. [Examples]

[0137] Next, embodiments of the present disclosure will be described with reference to examples, but the present disclosure is not limited to such embodiments.

[0138] Each value in the examples was measured by the following method.

[0139] (Composition of PTFE) 19 This was determined by F-NMR analysis.

[0140] (Average primary particle size of PTFE) The average primary particle size was determined by first determining the correlation between the transmittance when 550 nm light was incident on a predetermined cell into which a PTFE aqueous dispersion adjusted to a solid content of 0.15 mass was injected, and the number-average primary particle size calculated by measuring the directional diameter using transmission electron microscopy, and then applying the transmittance measured for the obtained sample to the above correlation (calibration curve method).

[0141] (Melting point of PTFE) The melting point of PTFE was determined using a differential scanning calorimeter X-DSC7000 (DSC) manufactured by Hitachi High-Tech Science Corporation. After pre-calibrating the temperature using standard samples of indium and lead, approximately 3 mg of PTFE that had not been heated above 300°C was placed in an aluminum pan and heated at a rate of 10°C per minute in the temperature range of 230-350°C under a nitrogen flow of 40 ml / min. Differential scanning calorimeter measurements were performed, and the temperature corresponding to the minimum point of the melting curve in the above range was measured as the melting point.

[0142] (Melting viscosity of PTFE) Melt viscosity was measured in accordance with ASTM D 1238, using a flow tester (Shimadzu Corporation) and a 2φ-8L die. A 2g sample, preheated to 380°C for 5 minutes, was maintained at the above temperature under a load of 0.7MPa. In the table, "Insoluble" means that the PTFE did not melt and therefore the melt viscosity could not be measured.

[0143] (Composition of perfluoroelastomers) 19 This was determined by F-NMR analysis.

[0144] (Mooney viscosity of perfluoroelastomer) The viscosity was measured at 170°C using an ALPHA TECHNOLOGIES MV2000E Mooney viscometer, in accordance with JIS K6300.

[0145] (Compression set (300℃)) The compression set was measured according to the methods described in ASTM D395 or JIS K6262. The O-rings prepared in the examples and comparative examples were compressed to a compression ratio of 25% at room temperature using a compression device (compressing an O-ring with a thickness (wire diameter) of 3.5 mm to a thickness of 2.625 mm). Next, the compression device with the compressed O-ring fixed in place was placed in an electric furnace and left at 300°C for 70 hours, after which the compression device was removed from the electric furnace. The O-ring was removed from the compression device and left in a constant temperature room at 23°C for 30 minutes, and the thickness (t2) of the O-ring was measured. The compression set was calculated using the following formula. Note that the closer the compression set is to 0%, the better the compression set characteristics of the bridged material. Compression set (%) = (t0 - t2) / (t0 - t1) × 100 t0: Original thickness of the O-ring (mm) t1: Spacer thickness (mm) t2: Thickness of the O-ring after compression test (mm) In the above test, t0 = 3.5 mm and t1 = 2.625 mm.

[0146] (Cracking rate (300℃)) The cracking status of the 12 O-rings after the "compression set (300°C)" test described above was visually inspected. The cracking rate was calculated using the following formula. Note that a cracking rate closer to 0% means that the cross-linked material is less likely to crack when compressed. Crack rate (%) = (Number of cracks) / (Number of tests) × 100 In the above test, the number of tests was 12.

[0147] (Compression set (temperature changed from 200°C to 70°C)) The compression set was measured according to the methods described in ASTM D395 or JIS K6262. The O-rings prepared in the examples and comparative examples were compressed to a compression ratio of 25% at room temperature using a compression device (compressing an O-ring with a thickness (wire diameter) of 3.5 mm to a thickness of 2.625 mm). Next, the compression device with the compressed O-ring fixed in place was placed in an electric furnace and left at 200°C for 70 hours, after which the compression device was removed from the electric furnace. Then, the compression device with the compressed O-ring fixed in place was placed in another electric furnace and left at 70°C for 24 hours. The O-ring was removed from the compression device and left in a constant temperature room at 23°C for 30 minutes, and the thickness of the O-ring (t2) was measured. The compression set was calculated using the following formula. Compression set (%) = (t0 - t2) / (t0 - t1) × 100 t0: Original thickness of the O-ring (mm) t1: Spacer thickness (mm) t2: Thickness of the O-ring after compression test (mm) In the above test, t0 = 3.5 mm and t1 = 2.625 mm.

[0148] (Cracking rate (temperature changed from 200°C to 70°C)) The cracking status of the 12 O-rings after the "compression set (temperature change from 200°C to 70°C)" test described above was visually inspected. The cracking rate was calculated using the following formula. Note that a cracking rate closer to 0% means that the cross-linked material is less likely to crack when compressed. Crack rate (%) = (Number of cracks) / (Number of tests) × 100 In the above test, the number of tests was 12.

[0149] (Plasma resistance (weight reduction rate of the crosslinked material before and after plasma treatment)) The O-rings (P24 size) fabricated in the examples and comparative examples were placed in a process chamber. Plasma generated using a radical generator was introduced into the process chamber, and the O-rings were exposed to the plasma under the following plasma irradiation conditions. The NF3 remote plasma weight loss rate was calculated from the mass of the O-rings before and after plasma irradiation. (Plasma irradiation conditions) Fluorine radical generator: Astron Atomic Fluorine Generator Model AX7657-2 (manufactured by MKS Corporation) Gas flow rate: Ar / NF3 = 1 (L / min) / 1 (L / min) Pressure: 3 Torr Irradiation temperature: 250℃ Irradiation time: 12 hours (the position of the O-ring inside the chamber is moved every 2 hours)

[0150] The following materials were used in the examples and comparative examples. Perfluoroelastomer: TFE / PMVE / CF2=CFOCF2CF(CF3)OCF2CF2CN = 59.3 / 39.9 / 0.8 (mol%) Mooney viscosity ML(1+20)(170 °C) = 66

[0151] Crosslinking agent: 2,2 - bis[3 - amino - 4 - (N - phenylamino)phenyl]hexafluoropropane

[0152] PTFE: PTFE having the physical properties described in Table 1

[0153] Example 1 880 g of an emulsion of perfluoroelastomer particles (solid content concentration 24% by weight) and 282 g of an emulsion of PTFE particles having the physical properties described in Table 1 (solid content concentration 15% by weight) were mixed at 23 °C, and dropped into 500 g of 10% nitric acid at 23 °C over 10 minutes for co - precipitation. The obtained co - precipitate was washed with water and dried at 70 °C using a vacuum dryer to obtain an elastomer composition in which PTFE was finely dispersed in the fluorine - containing elastomer.

[0154] When this elastomer composition was measured by differential thermal analysis (DTA), an absorption considered to be based on PTFE was observed at 327.7 °C.

[0155] 0.9 parts by mass of a crosslinking agent (2,2 - bis[3 - amino - 4 - (N - phenylamino)phenyl]hexafluoropropane) was mixed with 120 parts by mass of the obtained elastomer composition, and kneaded using an open roll to obtain a crosslinkable elastomer composition.

[0156] Furthermore, the crosslinkable elastomer composition was press - crosslinked at 180 °C for 30 minutes and then oven - crosslinked at 290 °C for 18 hours to produce an O - ring of size P24. Using the obtained O - ring, by the above method, compression set (300 °C), compression set (temperature change from 200 °C to 70 °C), and NF3 remote plasma reduction rate were measured. The results are shown in Table 1.

[0157] Examples 2 - 3 An elastomer composition, a crosslinkable elastomer composition, and an O-ring were obtained in the same manner as in Example 1. DTA measurements of the elastomer compositions revealed absorptions at 327.5°C in Example 2 and at 329.5°C in Example 3, which are thought to be due to PTFE.

[0158] Comparative Example 1 The perfluoroelastomer particle emulsion used in Example 1 at 23°C was added dropwise to 10% nitric acid at 23°C and allowed to coagulate. After washing the precipitate, it was dried to obtain perfluoroelastomer particles. On the other hand, nitric acid was added to the PTFE particle emulsion used in Example 1 and allowed to coagulate. The precipitate was washed and dried to obtain a white PTFE powder.

[0159] A crosslinkable elastomer composition was obtained by kneading 100 parts by mass of perfluoroelastomer particles with 20 parts by mass of PTFE powder and 0.9 parts by mass of a crosslinking agent (2,2-bis[3-amino-4-(N-phenylamino)phenyl]hexafluoropropane) in an open roll.

[0160] O-rings were fabricated in the same manner as in Examples 1-3. Compression set (300°C), compression set (temperature changed from 200°C to 70°C), and NF3 remote plasma weight loss rate were measured using the above method. The results are shown in Table 1.

[0161] Comparative Example 2 O-rings were fabricated in the same manner as in Examples 1-3, except that PTFE was used as shown in Table 1, and the obtained O-rings were evaluated in the same manner. The results are shown in Table 1.

[0162] [Table 1]

[0163] Examples 4-7 Except for changing the amounts of each material to achieve the compositions shown in Table 2, elastomer compositions, crosslinkable elastomer compositions, and O-rings were obtained in the same manner as in Example 1. The results, along with those of Example 1, are shown in Table 2.

[0164] Comparative Example 3 100 parts by mass of perfluoroelastomer particles prepared in Comparative Example 1 were mixed with 0.9 parts by mass of a crosslinking agent (2,2-bis[3-amino-4-(N-phenylamino)phenyl]hexafluoropropane) using an open roll to obtain a crosslinkable elastomer composition. O-rings were prepared from the crosslinkable elastomer composition in the same manner as in Example 1, and the obtained O-rings were evaluated in the same manner. The results are shown in Table 2.

[0165] [Table 2]

Claims

1. A method for producing a composition containing a perfluoroelastomer and polytetrafluoroethylene, The melt viscosity of the aforementioned polytetrafluoroethylene is 1.0 × 10³ to 7.0 × 10⁶ poise. By mixing the aqueous dispersion containing the perfluoroelastomer and the aqueous dispersion containing the polytetrafluoroethylene at 10 to 60°C, an aqueous dispersion containing the perfluoroelastomer and the polytetrafluoroethylene is prepared. By co-coagulating the perfluoroelastomer and the polytetrafluoroethylene in the obtained aqueous dispersion, A method for producing a composition containing the perfluoroelastomer and the polytetrafluoroethylene.

2. The manufacturing method according to claim 1, wherein the perfluoroelastomer and the polytetrafluoroethylene in the aqueous dispersion are co-coagulated by mixing the obtained aqueous dispersion with a coagulant.

3. The manufacturing method according to claim 2, wherein the temperature at which the aqueous dispersion and the coagulant are mixed is 10 to 60°C.

4. The manufacturing method according to claim 2, wherein the coagulating agent is an acid.

5. The manufacturing method according to claim 1 or 2, wherein the melting point of the polytetrafluoroethylene is 322°C or higher.

6. The manufacturing method according to claim 1 or 2, wherein the content of the polytetrafluoroethylene in the composition is 1 to 100 parts by mass per 100 parts by mass of the perfluoroelastomer.

7. A method for producing a crosslinked product, comprising producing the composition using the manufacturing method described in claim 1 or 2, and then crosslinking the composition to obtain a crosslinked product.

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