JP2010037558A - Fluorine-containing elastomer composition and sealing material including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorine-containing elastomer composition which provides a sealing material whose ozone resistance is improved and which has good heat resistance. <P>SOLUTION: This fluorine-containing elastomer composition comprises a perfluoroelastomer (A) comprising (a) 20 to 37% by mole of a perfluoroalkyl vinyl ether unit, (b) 0.1 to 2.5% by mole of a monomer unit having at least one, as a cross-linking part, selected from the group consisting of a nitrile group, a carboxy group and an alkoxycarbonyl group and (c) 61.5 to 79.9% by mole of a tetrafluoroethylene unit, and a specific cross-linking agent (B). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fluorine-containing elastomer composition and a sealing material comprising the composition.

  Fluorine-containing elastomers, especially perfluoroelastomers centered on tetrafluoroethylene (TFE) units, exhibit excellent chemical resistance, solvent resistance, and heat resistance, so they are widely used as sealing materials in harsh environments. Has been.

  However, as the technology advances, the required characteristics become more severe, and in the aerospace field, semiconductor manufacturing equipment field, chemical plant field, particularly semiconductor manufacturing equipment field, sealing properties under an ozone exposure environment are required.

  In response to such demands, attempts have been proposed to improve the heat resistance by devising a crosslinking system. As one of those directions, a curable composition in which a fluorinated elastomer having a nitrile group introduced as a crosslinking point is used and crosslinked with a specific bisaminophenyl compound is disclosed (for example, see Patent Document 1). Although the hardening composition in patent document 1 has the effect that it is excellent in thermal stability and chemical resistance when hardened | cured, it does not mention the tolerance in an ozone exposure environment.

  Patent Document 2 discloses a fluororubber composition in which mechanical strength and compression set at a high temperature are particularly improved, in which a carboxyl group and / or an alkoxycarbonyl group as a crosslinkable group is added to the end of the main chain and a branched chain. A fluororubber composition containing a fluorine-containing elastomer is described. Although the fluorine-containing elastomer copolymer which has a TFE unit and a perfluoromethyl vinyl ether (PMVE) unit is described as a fluororubber in patent document 2, content of PMVE unit contains as much as 40 mol% or more Therefore, there is a problem in terms of resistance and heat resistance in an ozone exposure environment.

  Patent Documents 3 and 4 describe a crosslinkable elastomer composition having a small impurity metal content as an elastomer composition excellent in plasma resistance and metal elution resistance. As the crosslinkable elastomers in Patent Documents 3 and 4, a fluorine-containing elastomer copolymer having TFE units and PMVE units is described, but the content of PMVE units is as large as 39.9 mol%. There is a problem in terms of resistance and heat resistance in an ozone exposure environment.

  Patent Document 5 describes a crosslinkable elastomer composition, and a fluorine-containing elastomer copolymer having a TFE unit and a PMVE unit is described as the crosslinkable elastomer in the elastomer composition. The content of the PMVE unit in the copolymer is as large as 40 mol% or more, and there is a problem in terms of resistance in an ozone exposure environment and heat resistance.

  Patent Document 6 describes a crosslinkable elastomer composition that is excellent in chemical resistance, mechanical strength, and heat resistance. The crosslinkable elastomer composition uses a bisaminophenyl compound as a crosslinker, and discloses a copolymer comprising monomer units having TFE units, PMVE units, and nitrile groups as crosslinkable sites as perfluoroelastomers. However, since the content of the PMVE unit is contained as much as 38 to 42 mol%, there is a problem in terms of resistance in an ozone exposure environment.

  Patent Document 7 describes a fluorine-containing elastomer composition having excellent heat resistance and excellent chemical resistance such as steam resistance. The fluorine-containing elastomer in the fluorine-containing elastomer composition has a TFE unit, a perfluoro (alkyl vinyl ether) unit, and a hydrocarbon olefin unit such as ethylene. There is a problem.

  Patent Document 8 describes a fluorine-containing elastomer composition that provides a rubber vulcanizate having good vulcanization properties and good compression set. The fluorine-containing elastomer in the fluorine-containing elastomer composition contains a copolymer having TFE units and perfluoro (lower alkyl vinyl ether) units such as PMVE, and further contains a specific bisaminophenyl compound as a crosslinking agent. A curable composition that is cross-linked by a fluoroelastomer composition is disclosed. The curable composition in Patent Document 8 does not mention resistance in an ozone exposure environment.

  Patent Documents 9 to 11 describe curable perfluoroelastomer compositions having good vulcanization properties, excellent thermal stability under high temperature conditions, and good compression set. The fluorine-containing elastomer in the elastomer composition contains a copolymer having a TFE unit and a perfluoro (alkyl vinyl ether) unit such as PMVE, and further has a specific bisaminophenyl compound as a crosslinking agent. Cured compositions that are cross-linked by materials are disclosed. The hardening composition in patent documents 9-11 is not mentioned about the tolerance in ozone exposure environment.

  U.S. Patent No. 6,057,031 describes a curable perfluoroelastomer composition suitable for applications that require thermal and hydrolytic stability. The fluorine-containing elastomer in the elastomer composition contains a copolymer having a TFE unit, a perfluoro (alkyl vinyl ether) unit such as PMVE, and a monomer unit having a nitrile group as a crosslinking site, and bisamino as a crosslinking agent. A curable composition for crosslinking a fluorine-containing elastomer composition having a specific bisaminophenyl compound such as phenol, benzidine, or tetraminebenzophenone is disclosed. The cured composition in Patent Document 12 does not mention resistance in an ozone exposure environment.

Japanese Patent Laid-Open No. 6-263955 International Publication No. 00/29479 Pamphlet International Publication No. 00/42100 Pamphlet International Publication No. 00/42093 Pamphlet International Publication No. 01/79337 Pamphlet International Publication No. 01/32773 pamphlet International Publication No. 01/53411 Pamphlet JP-A-8-120144 Special table 2007-502890 Special Table 2002-514241 Special Table 2002-515525 JP 59-109546 A

  An object of the present invention is to provide a fluorine-containing elastomer composition that provides a molded article that is improved in ozone resistance and excellent in heat resistance.

（式中、Ｒｆ¹およびＲｆ²は、同じかまたは異なり、いずれも炭素数１〜２０のパーフルオロアルキル基またはパーフルオロオキシアルキル基である）
で示される架橋剤（Ｂ）を含む含フッ素エラストマー組成物に関する。 In the present invention, (a) the content of perfluoroalkyl vinyl ether units is 20 to 37 mol%,
(B) The content of the monomer unit having at least one selected from the group consisting of a nitrile group, a carboxyl group and an alkoxycarbonyl group as a crosslinking site is 0.1 to 2.5 mol% and (c) a tetrafluoroethylene unit Content is 61.5-79.9 mol%
Perfluoroelastomer (A),
Formula (1):

(Wherein Rf ¹ and Rf ² are the same or different and both are perfluoroalkyl groups or perfluorooxyalkyl groups having 1 to 20 carbon atoms)
The fluorine-containing elastomer composition containing the crosslinking agent (B) shown by these.

  The perfluoroalkyl vinyl ether unit (a) is preferably a perfluoromethyl vinyl ether unit.

  The monomer unit (b) is preferably a perfluoro (8-cyano-5-methyl-3,6-dioxa-1-octene) unit.

で示される化合物であることが好ましい。 The crosslinking agent (B) is represented by the formula (1a):

It is preferable that it is a compound shown by these.

  The present invention also relates to a sealing material using the fluorine-containing elastomer composition.

  According to the present invention, by combining a fluorine-containing elastomer composition containing a specific fluorine-containing elastomer and a specific crosslinking agent, a fluorine-containing elastomer molded article having excellent ozone resistance and heat resistance even in an ozone exposure environment. The fluorine-containing elastomer composition which provides can be provided.

  The fluorine-containing elastomer composition of the present invention comprises (a) a perfluoroalkyl vinyl ether (hereinafter also referred to as PAVE) unit, (b) a monomer unit having a cured site, and (c) tetrafluoroethylene (hereinafter also referred to as TFE) unit. Perfluoroelastomer (A) containing a specific amount and a crosslinking agent (B).

  The content of the PAVE unit (a) in the perfluoroelastomer (A) is 20 mol in the perfluoroelastomer (A) from the viewpoint that it does not become a property close to the resin and the property as a rubber elastic body is not lost. % Or more, preferably 24 mol% or more, and more preferably 27 mol% or more. Further, the content of the PAVE unit is excellent in ozone resistance and excellent in heat resistance such as compression set at a high temperature, and is not more than 37 mol% in the perfluoroelastomer (A), and preferably not more than 35 mol%. 32 mol% or less is more preferable.

  Examples of PAVE in this case include perfluoromethyl vinyl ether (hereinafter also referred to as PMVE), perfluoropropyl vinyl ether, and the like, and these are used alone or in any combination as long as the effects of the present invention are not impaired. be able to.

  Of these, PMVE is preferable because the cured product has more rubber elasticity and excellent mechanical strength.

  The content of the monomer unit (b) having at least one selected from the group consisting of a nitrile group, a carboxyl group and an alkoxycarboxyl group as a cross-linking site increases the cross-linking density and improves the sealing property of the sealing material. It is 0.1 mol% or more in an elastomer (A), 0.2 mol% or more is preferable and 0.3 mol% or more is more preferable. Further, the content of the monomer unit (b) is 2.5 mol% or less in the perfluoroelastomer (A) and 1.5 mol% or less in the perfluoroelastomer (A) from the viewpoint of suppressing a decrease in elongation due to an increase in the crosslinking density. Preferably, 1.0 mol% or less is more preferable.

Examples of the monomer unit (b) include a formula (2):
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m (CF 2) n -X 1 (2)
(Wherein m is an integer of 0 to 5, n is an integer of 1 to 3, X ¹ is a nitrile group, a carboxyl group or an alkoxycarbonyl group)
And the like. These can be used alone or in any combination.

  This nitrile group, carboxyl group or alkoxycarbonyl group can function as a crosslinking point. Moreover, it is preferable that it is a nitrile group containing monomer whose crosslinking point in a monomer unit (b) is a nitrile group from the point which is excellent in crosslinking reactivity.

Specific examples of the monomer unit (b) include formulas (3) to (19):
_{CY 2 = CY (CF 2)} n -X 2 (3)
(In the formula, Y is a hydrogen atom or a fluorine atom, and n is an integer of 1 to 8)
^{_{CF 2 = CFCF 2 R f 3}} -X 2 (4)
(In the formula, R _f ³ is — (OCF ₂ ) _n — (n is an integer of 1 to 5))
CF ₂ = CFCF ₂ (OCF (CF ₃ ) CF ₂ ) _{m
(OCH 2 CF 2 CF 2)} n OCH 2 CF 2 -X 2 (5)
(In the formula, m is an integer of 0 to 5, and n is an integer of 0 to 5)
CF ₂ = CFCF ₂ (OCH ₂ CF ₂ CF ₂ ) _m
(OCF (CF ₃ ) CF ₂ ) _n OCF (CF ₃ ) -X ² (6)
(In the formula, m is an integer of 0 to 5, and n is an integer of 0 to 5)
_{CF 2 = CF (OCF 2 CF} (CF 3)) m O (CF 2) n -X 2 (7)
(In the formula, m is an integer of 0 to 5, and n is an integer of 1 to 8.)
_{CF 2 = CF (OCF 2 CF} (CF 3)) m -X 2 (8)
(Where m is an integer from 1 to 5)
_{CF 2 = CFOCF 2 (CF (} CF 3) OCF 2) n CF (-X 2) CF 3 (9)
(Where n is an integer from 1 to 4)
_{CF 2 = CFO (CF 2)} n OCF (CF 3) -X 2 (10)
(Where n is an integer from 2 to 5)
_{CF 2 = CFO (CF 2)} n - (C 6 H 4) -X 2 (11)
(Where n is an integer from 1 to 6)
_{CF 2 = CF (OCF 2 CF} (CF 3)) n OCF 2 CF (CF 3) -X 2 (12)
(Where n is an integer from 1 to 2)
_{CH 2 = CFCF 2 O (CF} (CF 3) CF 2 O) n CF (CF 3) -X 2 (13)
(Where n is an integer from 0 to 5)
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m (CF 2) n -X 2 (14)
(In the formula, m is an integer of 0 to 5, and n is an integer of 1 to 3)
_{CH 2 = CFCF 2 OCF (CF} 3) OCF (CF 3) -X 2 (15)
_{CH 2 = CFCF 2 OCH 2 CF} 2 -X 2 (16)
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m CF 2 CF (CF 3) -X 2 (17)
(Where m is an integer of 0 or more)
_{CF 2 = CFOCF (CF 3)} CF 2 O (CF 2) n -X 2 (18)
(Where n is an integer of 1 or more)
_{CF 2 = CFOCF 2 OCF 2 CF} (CF 3) OCF 2 -X 2 (19)
(In the general formulas (3) to (19), X ² represents a nitrile group (—CN group), a carboxyl group (—COOH group) or an alkoxycarbonyl group (—COOR ⁵ group, R ⁵ has 1 to 10 carbon atoms). And a monomer unit obtained by the monomer represented by (1), which may contain a fluorine atom. Among these, the perfluoroelastomer (A) has excellent heat resistance, and when a perfluoroelastomer is synthesized by a polymerization reaction, a perfluoro compound containing no hydrogen atom is used to suppress a decrease in molecular weight due to chain transfer. preferable. Further, a compound having a CF ₂ ═CFO— structure is preferable from the viewpoint of excellent polymerization reactivity with tetrafluoroethylene, and is a perfluoro (8-cyano-5-methyl-3,6-dioxa-1-octene) unit. It is preferable.

  The content of the TFE unit (c) in the perfluoroelastomer (A) is excellent in ozone resistance, and in heat resistance such as compression set at high temperature, 61.5 mol in the perfluoroelastomer (A). %, Preferably 65 mol% or more, more preferably 68 mol% or more. In addition, the content of the TFE unit is 79.9 mol% or less in the perfluoroelastomer (A) from the viewpoint that the properties as a rubber elastic body are not lost and the properties close to that of the resin are not lost. % Or less is preferable, and 73 mol% or less is more preferable.

  Specific examples of such perfluoroelastomer (A) include those described in JP-T-9-512569, WO00 / 29479, JP-A-11-92529 and the like.

  These perfluoroelastomers (A) can be produced by a conventional method. These perfluoroelastomers (A) can be produced by a polymerization method such as an emulsion polymerization method, a suspension polymerization method, or a solution polymerization method, but the emulsion polymerization method is preferred from the viewpoint of easy handling.

  The radical polymerization initiator used in the present invention may be any radical polymerization initiator conventionally used for the polymerization of fluororubber, and examples thereof include organic and inorganic peroxides and azo compounds. Typical initiators include persulfates, carbonate peroxides, peroxide esters and the like, and a preferred initiator is ammonium persulfate (APS). APS may be used alone or in combination with a reducing agent such as sulfites.

  A wide range of emulsifiers can be used as the emulsion polymerization. From the viewpoint of suppressing the chain transfer reaction to the emulsifier molecule that occurs during the polymerization, the carboxylic acid having a fluorocarbon chain or a fluoropolyether chain is used. Salts are desirable. The amount of the emulsifier used is preferably about 0.05 to 2% by mass, and particularly preferably 0.2 to 1.5% by mass of the added water.

  The monomer mixed gas used in the present invention is explosive as described in GH Kalb et al., Advances in Chemistry Series., 129, 13 (1973). Therefore, it is necessary to devise a polymerization apparatus so as not to generate a spark or the like as an ignition source.

  The polymerization pressure can be varied within a wide range. Generally, it is the range of 0.5-7MPa. The higher the polymerization pressure, the higher the polymerization rate. Therefore, from the viewpoint of improving productivity, the polymerization pressure is preferably 0.7 MPa or more.

  As a method for introducing at least one group selected from the group consisting of a nitrile group, a carboxyl group and an alkoxycarbonyl group into the fluorine-containing elastomer used in the present invention, as described above, at the time of producing the fluorine-containing elastomer, it has a crosslinking site. It can be introduced by adding a monomer and copolymerizing, but as another method, for example, by treating the polymerization product with an acid, a metal salt of a carboxylic acid present in the polymerization product or A method for converting a group such as an ammonium salt into a carboxyl group can also be mentioned. As the acid treatment method, for example, washing with hydrochloric acid, sulfuric acid, nitric acid or the like, or a method of bringing the mixture system after polymerization reaction with these acids to pH 3 or less is suitable.

  Moreover, a crosslinkable elastomer containing iodine or bromine can be oxidized with fuming nitric acid or fuming sulfuric acid to introduce a carboxyl group.

  The fluorine-containing elastomer composition of the present invention preferably has a group capable of acting as a crosslinking site of the fluorine-containing elastomer described above and a crosslinking agent (B) capable of crosslinking reaction.

で示される化合物である。 The crosslinking agent (B) used in the present invention has a structure in which the structure after crosslinking becomes an aromatic ring structure and is stabilized, so that the heat resistance is improved, and the ozone resistance in the molded product after crosslinking is improved. From equation (1):

It is a compound shown by these.

Rf ¹ and Rf ² in the formula (1) are the same or different and both are perfluoroalkyl groups or perfluorooxyalkyl groups. The carbon number of the perfluoroalkyl group or perfluorooxyalkyl group is 1 or more from the viewpoint that it is excellent in improving the heat resistance of the crosslinking point after crosslinking by introducing a fluorine-containing group. The carbon number of the perfluoroalkyl group or perfluorooxyalkyl group is 20 or less, and preferably 10 or less, from the viewpoint of reducing the amount of expensive fluorine-containing compound used in the synthesis of the crosslinking agent.

Specific examples of the perfluoroalkyl group in Rf ¹ and Rf ² include a perfluoromethyl group, a perfluoropropyl group, and CF ₃ CF ₂ CF ₂ OCFCF ₃ CF ₂ O—. A perfluoromethyl group is preferable because it is excellent in that it is easily available.

で示される化合物であることが、合成が容易であるという点で好ましい。 As a specific example of the formula (1), the formula (1a):

It is preferable that it is a compound shown by the point that a synthesis | combination is easy.

  The content of the crosslinking agent (B) is preferably 0.2 parts by mass or more, more preferably 0.4 parts by mass or more with respect to 100 parts by mass of the elastomer, from the viewpoint of improving the crosslinkability of the composition. More preferably, 6 parts by mass or more. In addition, the content of the crosslinking agent (B) is preferably 10.0 parts by mass or less, more preferably 2.0 parts by mass or less, with respect to 100 parts by mass of the elastomer in terms of improving the crosslinkability of the composition. 1.0 mass part or less is still more preferable.

  In the fluorine-containing elastomer composition of the present invention, a general additive contained in the crosslinkable elastomer composition, for example, a filler, a processing aid, a plasticizer, a colorant and the like can be contained as necessary. Moreover, you may contain 1 or more types of the usual crosslinking agent and crosslinking accelerator different from the said thing. Moreover, you may mix and use another type of elastomer in the range which does not impair the effect of this invention.

  Examples of fillers include organic fillers, and organic pigments; polyimides, polyamideimides, polyetherimides, and other imide structures from the viewpoints of heat resistance and plasma resistance (low particle properties and low weight loss during plasma irradiation). Imide fillers having; ketone engineer plastics such as polyetheretherketone (PEEK) and polyetherketone (PEK) are preferred, and organic pigments are particularly preferred.

  Examples of organic pigments include condensed azo pigments, isoindolinone pigments, quinacridone pigments, diketopyrrolopyrrole pigments, anthraquinone pigments, among them, excellent heat resistance and chemical resistance, A quinacridone pigment, a diketopyrrolopyrrole pigment, and an anthraquinone pigment are preferable, and a quinacridone pigment is more preferable because it has little influence on the properties of the molded article.

  Furthermore, the fluorine-containing crosslinkable composition of the present invention may contain a general filler.

  Common fillers include organic fillers made of engineering plastics such as polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyoxybenzoate, and polytetrafluoroethylene powder, as well as aluminum oxide, silicon oxide, yttrium oxide, and oxidation. Metal oxide fillers such as titanium; metal carbide fillers such as silicon carbide and aluminum carbide; metal nitride fillers such as silicon nitride and aluminum nitride; aluminum fluoride, carbon fluoride, barium sulfate, carbon black, silica, clay, talc And inorganic fillers.

  Among these, aluminum oxide, yttrium oxide, silicon oxide, polyimide, and carbon fluoride are preferable from the viewpoint of the shielding effect of various plasmas.

  Moreover, you may contain the said inorganic filler and an organic filler individually or in combination of 2 or more types.

  The composition of the present invention can be prepared by mixing each of the above components using a normal rubber processing machine, for example, an open roll, a Banbury mixer, a kneader or the like. In addition, it can be prepared by a method using a closed mixer or a method of co-coagulation from emulsion mixing.

  The hardness of the crosslinked product obtained by crosslinking the fluorine-containing elastomer of the present invention can be measured in accordance with JIS K6253 (Shore A). The hardness of the cross-linked product is preferably 50 or more, more preferably 55 or more, and still more preferably 60 or more from the point of view that the sealing property of the sealing material using the elastomer composition of the present invention is good. In addition, the hardness of the crosslinked product is preferably 95 or less, more preferably 90 or less, and even more preferably 85 or less, from the viewpoint that the sealing performance of the sealing material using the elastomer composition of the present invention is good.

  The crosslinked product obtained by crosslinking and molding the fluorine-containing elastomer composition of the present invention is excellent in chemical resistance, mechanical strength, and heat resistance, and thus is suitable as a sealing material for sealing a semiconductor device, for example. Examples of the sealing material include O-ring, square ring, gasket, packing, oil seal, bearing seal, and lip seal.

  The semiconductor manufacturing apparatus referred to in the present invention is not particularly limited to an apparatus for manufacturing a semiconductor, and is widely used for a semiconductor that requires a high degree of cleanliness, such as an apparatus for manufacturing a liquid crystal panel or a plasma panel. This includes all manufacturing equipment used in the field, and examples include the following.

(1) Etching equipment Dry etching equipment Plasma etching equipment Reactive ion etching equipment Reactive ion beam etching equipment Sputter etching equipment Ion beam etching equipment Wet etching equipment Ashing equipment

(2) Cleaning device Dry etching cleaning device UV / O ₃ cleaning device Ion beam cleaning device Laser beam cleaning device Plasma cleaning device Gas etching cleaning device Extraction cleaning device Soxhlet extraction cleaning device High temperature high pressure extraction cleaning device Microwave extraction cleaning device Supercritical extraction Cleaning device

(3) Exposure equipment Stepper Coater / Developer

(4) Polishing device CMP device

(5) Film formation equipment CVD equipment Sputtering equipment

(6) Diffusion and ion implantation equipment Oxidation diffusion equipment Ion implantation equipment

  Next, the present invention will be described with reference to production examples and examples, but the present invention is not limited to such examples.

を２３．４ｇ、（ＮＨ₄）₂ＣＯ₃を０．２１ｇ仕込み、系内を窒素ガスで充分に置換し脱気したのち、６００ｒｐｍで撹拌しながら、５２℃に昇温し、テトラフルオロエチレン（ＴＦＥ）とパーフルオロメチルビニルエーテル（ＰＭＶＥ）の混合ガス（ＴＦＥ／ＰＭＶＥ＝３５／６５モル比）を、内圧が０．７８ＭＰａ・Ｇになるように仕込んだ。ついで、ＣＦ₂＝ＣＦＯＣＦ₂ＣＦＣＦ₃ＯＣＦ₂ＣＦ₂ＣＮ（ＣＮＶＥ）を０．８５ｇ窒素で圧入した後、過硫酸アンモニウム（ＡＰＳ）１２．３ｇを、水３０ｇに溶解し、窒素で圧入して反応を開始した。 Production Example 1 (Synthesis of perfluoroelastomer A)
As a stirring blade, a stainless steel autoclave with an internal volume of 6 liters without an ignition source fitted with a Max Blend blade, and 2.338 liters of pure water and emulsifier

Was charged with 23.4 g of (NH ₄ ) ₂ CO ₃ and 0.21 g of (NH ₄ ) ₂ CO ₃ was thoroughly substituted with nitrogen gas. After deaeration, the mixture was heated to 52 ° C. while stirring at 600 rpm, and tetrafluoroethylene ( A mixed gas (TFE / PMVE = 35/65 molar ratio) of TFE) and perfluoromethyl vinyl ether (PMVE) was charged so that the internal pressure was 0.78 MPa · G. Next, CF ₂ = CFOCF ₂ CFCF ₃ OCF ₂ CF ₂ CN (CNVE) was injected with 0.85 g of nitrogen, and then 12.3 g of ammonium persulfate (APS) was dissolved in 30 g of water, and the reaction was performed by injecting with nitrogen. Started.

  As the polymerization proceeds, the pressure in the tank decreases. When the pressure reached 0.73 MPa · G, TFE and PMVE were injected at a ratio of 70/30 mol%, and the pressure was increased to 0.83 MPa · G. . Thereafter, TFE and PMVE were injected in the same manner as the reaction progressed, and the pressure was increased and decreased repeatedly between 0.73 and 0.83 MPa · G, and 400 g of total TFE and 284 g of PMVE were injected until the polymerization was completed. During the polymerization, 14.45 g of CNVE was added in 17 divided portions. After completion of the polymerization, the autoclave was cooled to release unreacted monomers to obtain 2991.2 g of an aqueous dispersion having a solid content concentration of 22.3% by mass. The polymerization time was 6.2 hours.

  1000 g of this aqueous dispersion was diluted with 1000 g of pure water, and slowly added to 5000 g of a 3.5 wt% aqueous hydrochloric acid solution with stirring. After the addition, the mixture was stirred for 5 minutes, and then the coagulated product was filtered off. The obtained polymer was further poured into 5000 g of pure water, stirred for 5 minutes, and filtered again. Thereafter, washing and filtering were repeated, and the polymer was taken out when the pH of the washing water after washing was 6 or more. In the same manner, after treating 2991 g of the aqueous dispersion obtained by polymerization, all the obtained polymers were vacuum dried at 70 ° C. for 48 hours to obtain 615 g of the dried polymer (perfluoroelastomer A). Obtained.

As a result of measuring the obtained polymer by ¹⁹ F-NMR (solid NMR), the monomer unit composition of this polymer was TFE / PMVE / CNVE (69.2 / 30.4 / 0.4 mol%). Met.

を２３．４ｇ、（ＮＨ₄）₂ＣＯ₃を０．２１ｇ仕込み、系内を窒素ガスで充分に置換し脱気したのち、６００ｒｐｍで撹拌しながら、５２℃に昇温し、テトラフルオロエチレン（ＴＦＥ）とパーフルオロメチルビニルエーテル（ＰＭＶＥ）の混合ガス（ＴＦＥ／ＰＭＶＥ＝２４／７６モル比）を、内圧が０．７８ＭＰａ・Ｇになるように仕込んだ。ついで、ＣＮＶＥを０．８５ｇ、窒素で圧入した後、過硫酸アンモニウム（ＡＰＳ）１２．３ｇを、水３０ｇに溶解し、窒素で圧入して反応を開始した。 Production Example 2 (Synthesis of perfluoroelastomer B)
As a stirring blade, a stainless steel autoclave with an internal volume of 6 liters without an ignition source fitted with a Max Blend blade, and 2.338 liters of pure water and emulsifier

Was charged with 23.4 g of (NH ₄ ) ₂ CO ₃ and 0.21 g of (NH ₄ ) ₂ CO ₃ was thoroughly substituted with nitrogen gas. After deaeration, the mixture was heated to 52 ° C. while stirring at 600 rpm, and tetrafluoroethylene ( A mixed gas (TFE / PMVE = 24/76 molar ratio) of TFE) and perfluoromethyl vinyl ether (PMVE) was charged so that the internal pressure was 0.78 MPa · G. Subsequently, 0.85 g of CNVE was injected with nitrogen and then 12.3 g of ammonium persulfate (APS) was dissolved in 30 g of water and the reaction was started by injecting with nitrogen.

  As the polymerization proceeds, the pressure in the tank decreases, so when the pressure reached 0.73 MPa · G, TFE and PMVE were injected at a ratio of 60/40 mol%, and the pressure was increased to 0.83 MPa · G. . Thereafter, TFE and PMVE were injected in the same manner as the reaction proceeded, and the pressure was increased and decreased repeatedly between 0.73 and 0.83 MPa · G, and 327 g of total TFE and 355 g of PMVE were injected until the polymerization was completed. During the polymerization, 14.45 g of CNVE was added in 17 divided portions. After completion of the polymerization, the autoclave was cooled to release unreacted monomers to obtain 2983 g of an aqueous dispersion having a solid content concentration of 21.3% by mass. The polymerization time was 8.0 hours.

  1000 g of this aqueous dispersion was diluted with 1000 g of pure water, and slowly added to 5000 g of a 3.5 wt% aqueous hydrochloric acid solution with stirring. After the addition, the mixture was stirred for 5 minutes, and then the coagulated product was filtered off. The obtained polymer was further poured into 5000 g of pure water, stirred for 5 minutes, and filtered again. Thereafter, washing and filtering were repeated, and the polymer was taken out when the pH of the washing water after washing was 6 or more. In the same manner, after treating 2983 g of the aqueous dispersion obtained by polymerization, all the obtained polymers were vacuum dried at 70 ° C. for 48 hours to obtain 610 g of dried polymer (perfluoroelastomer B). Obtained.

The obtained polymer was measured by ¹⁹ F-NMR (solid NMR) in the same manner as in Production Example 1. As a result of ¹⁹ F-NMR analysis, the monomer unit composition of this polymer was TFE / PMVE / CNVE (57.4 / 42.2 / 0.4 mol%).

で示される架橋剤（Ｂ）（Ｔｅｔｒａｍｉｎｅ ＡＦ（ＷＯ０１／３８２９０をもとに合成した））をパーフルオロエラストマーＡ：架橋剤（Ｂ）＝１００：０．６４（質量比）で混合し、オープンロールにて混練して架橋可能な含フッ素エラストマー組成物を調製した。この組成物について、架橋性を調べた。結果を表１に示す。 Example 1
Perfluoroelastomer A obtained in Production Example 1 and formula (1a):

A cross-linking agent (B) represented by the formula (Tetramine AF (synthesized based on WO01 / 38290)) is mixed in a perfluoroelastomer A: cross-linking agent (B) = 100: 0.64 (mass ratio), and an open roll And a crosslinkable fluorine-containing elastomer composition was prepared. This composition was examined for crosslinkability. The results are shown in Table 1.

(Crosslinking)
For each composition for crosslinking, a vulcanization curve was determined at 180 ° C. with a JSR type curlastometer type II, and the minimum torque (ML), maximum torque (MH), induction time (T10) and optimum vulcanization time (T90) Ask for.

  Further, this fluorine-containing elastomer composition was subjected to crosslinking by pressing at 180 ° C. for 20 minutes, and then subjected to oven crosslinking at 290 ° C. for 18 hours to test a crosslinked O-ring of P-24 standard (JIS B 2401). A sample and a crosslinked sheet having a thickness of 2 mm were prepared. Using these O-ring test samples and the cross-linked sheet, normal physical properties were measured by the following measurement method, and an ozone resistance test and a heat resistance test were further performed. The results are shown in Table 1.

(Normal physical properties)
In accordance with JIS K6251, a No. 6 dumbbell is used to measure 100% elongation tensile stress (M100), tensile strength (TB) at break, and elongation at break (EB) of a 2 mm thick crosslinked sheet. Further, the hardness (Shore A) is measured according to JIS K6253.

(Heat resistance test)
According to JIS B2401, the compression set (25% compression) of an O-ring test sample at 310 ° C. for 70 hours is measured.

(Ozone resistance test)
Oxygen gas of 3500 ml / min and nitrogen gas of 5.6 ml / min are supplied to an ozone generation / supply device (trade names: GR-RB20, SGX-A11MN (modified), both manufactured by Sumitomo Seiki Kogyo Co., Ltd.) and 185 g / m generating a gas containing ³ N concentration ozone. This ozone gas was adjusted to a flow rate of 3000 ml / min with a mass flow controller, and the O-ring test sample was poured into a sealed SUS container, and the O-ring test sample was exposed to ozone gas for 32 hours. Meanwhile, the temperature of the SUS container was adjusted so that the internal temperature was 138 ° C.

  The O-ring test sample exposed to ozone gas and the O-ring test sample that was not exposed were immersed in Fluorinert FC-84 (manufactured by Sumitomo 3M) at 23 ° C. for 46 hours, then taken out, and the mass immediately after immersion was measured. . Since the sample swells by dipping, the mass change from before dipping is calculated as the swelling ratio as in the following equation.

Swelling ratio = ((mass after immersion) − (mass before immersion)) / (mass before immersion) × 100 (%)
Change rate of swelling rate = (swelling rate after exposure to ozone) / (swelling rate before exposure to ozone) × 100-100 (%)
The swelling rate correlates with the crosslinking density, and the higher the crosslinking density, the smaller the swelling rate. When molecular chains and cross-linking points are cleaved by ozone exposure, the cross-linking density of the sample decreases after exposure to ozone, and the swelling rate increases compared to before exposure to ozone. Therefore, the smaller the rate of change of the swelling rate before and after exposure to ozone, the better the ozone resistance, because the molecular chain and the crosslinking point are not broken by exposure to ozone.

  In addition, dissolution by immersion indicates that the frequency of cutting of molecular chains and crosslinking points is higher than in the case of swelling.

(Compression set test after exposure to ozone)
Under the above conditions, the compression set (25% compression) of the O-ring test sample exposed to the gas containing ozone is measured according to JIS B2401 at 200 ° C. for 5 hours according to JIS B2401.

（ＡＦＴＡ−Ｐｈ ジャーナル・オブ・ポリマー・サイエンスのポリマー・ケミストリー編、Ｖｏｌ．２０、２３８１〜２３９３頁（１９８２）に記載の方法で合成した）０．９質量部を用い、プレス加硫時間を９０分間にした以外は、実施例１と同様の方法にて、架橋物を製造し、実施例１と同様にして物性を測定した。結果を表１に示す。 Comparative Example 1
In Example 1, instead of (Tetramine AF) as the crosslinking agent (B), the formula:

Using 0.9 parts by mass (synthesized by the method described in AFTA-Ph Journal of Polymer Science, Polymer Chemistry, Vol. 20, pages 2381 to 2393 (1982)), press vulcanization time was 90 A crosslinked product was produced in the same manner as in Example 1 except that the time was changed to minutes, and the physical properties were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2
A crosslinked product was produced in the same manner as in Example 1 except that the perfluoroelastomer B obtained in Production Example 2 was used, and the physical properties were measured in the same manner as in Example 1. The results are shown in Table 1. In addition, when the compression set (25% compression) was measured in Comparative Example 2, it was impossible to measure because all the samples were destroyed.

Comparative Example 3
A crosslinked product was produced in the same manner as in Comparative Example 2 except that 0.9 part by mass of AFTA-Ph was used as the crosslinking agent (B), and the physical properties were measured in the same manner as in Example 1. The results are shown in Table 1.

（ＢＡＰ（東京化成工業（株）製））を０．６３質量部用いた以外は、比較例２と同様の方法にて、架橋物を製造し、実施例１と同様にして物性を測定した。結果を表１に示す。 Comparative Example 4
As the crosslinking agent (B), the formula:

A crosslinked product was produced in the same manner as in Comparative Example 2 except that 0.63 parts by mass (BAP (manufactured by Tokyo Chemical Industry Co., Ltd.)) was used, and the physical properties were measured in the same manner as in Example 1. . The results are shown in Table 1.

（３，３’−Ｄｉａｍｉｎｏｂｅｎｚｉｄｉｎｅ（Ａｌｄｒｉｃｈ製））を０．３７質量部用いた以外は、実施例１と同様の方法にて、架橋物を製造し、実施例１と同様にして物性を測定した。結果を表１に示す。 Comparative Example 5
As the crosslinking agent (B), the formula:

A crosslinked product was produced in the same manner as in Example 1 except that 0.37 parts by mass of (3,3′-Diaminobenzoidine (manufactured by Aldrich)) was used, and the physical properties were measured in the same manner as in Example 1. . The results are shown in Table 1.

Claims (5)

(A) The content of perfluoroalkyl vinyl ether units is 20 to 37 mol%,
(B) The content of the monomer unit having at least one selected from the group consisting of a nitrile group, a carboxyl group and an alkoxycarbonyl group as a crosslinking site is 0.1 to 2.5 mol% and (c) a tetrafluoroethylene unit Content is 61.5-79.9 mol%
Perfluoroelastomer (A),
Formula (1):

(In the formula, Rf ¹ and Rf ² are the same or different and both are perfluoroalkyl groups or perfluorooxyalkyl groups having 1 to 20 carbon atoms)
The fluorine-containing elastomer composition containing the crosslinking agent (B) shown by these.   The fluorine-containing elastomer composition according to claim 1, wherein the perfluoroalkyl vinyl ether unit (a) is a perfluoromethyl vinyl ether unit.   The fluorine-containing elastomer composition according to claim 1 or 2, wherein the monomer unit (b) is a perfluoro (8-cyano-5-methyl-3,6-dioxa-1-octene) unit. The crosslinking agent (B) is represented by the formula (1a):

The fluorine-containing elastomer composition according to claim 1, which is a compound represented by the formula:   The sealing material using the fluorine-containing elastomer composition in any one of Claims 1-4.