JP2008045001A - Peroxide-cross-linkable composition and molded article comprizing the same, fuel penetration-resistant sealant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a peroxide-cross-linkable composition which can give molded articles having excellent fuel penetration resistance and excellent sealability. <P>SOLUTION: This peroxide-cross-linkable composition comprises (A) a peroxide-cross-linkable fluororubber, (B) a silicone raw rubber or silicone rubber, and (C) an onium salt. The component (A), the component (B) and the component (C) are preferably contained in amounts of 100 pts.wt., 5 to 200 pts.wt, and 0.01 to 15 pts.wt., respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a peroxide crosslinking composition that can provide a molded article having excellent fuel permeation resistance and excellent sealing properties. The present invention also relates to a molded product obtained by crosslinking the composition and a fuel-permeable sealing material.

  Fluoro rubber is excellent in properties such as fuel permeability, slidability, heat resistance, chemical resistance, weather resistance, and electrical properties, and is used in a wide range of fields such as automobiles, industrial machinery, OA equipment, and electrical and electronic equipment. ing.

  For example, in the automobile industry, it is used as a sealant for engines and peripheral devices, AT devices, fuel systems and peripheral devices, etc., but with the recent environmental regulations, there is a SHED (Sealed Housing for Evaporative Determination) regulation. There is a demand for the development of a fuel-based rubber material that is reinforced and particularly has fuel permeability. In addition to fuel permeation resistance, fuel-based rubber materials are also required to have various properties such as sealability, processability, oil resistance, and cold resistance, and fluororubber has insufficient cold resistance, Silicone rubber has insufficient heat resistance, oil resistance and fuel permeation resistance.

  In order to solve this problem, various composite materials in which fluorine rubber and silicone rubber are combined have been studied. Since these two types of rubber have the properties of complementing each other, a new material can be provided if they can be successfully compounded by blending, alloying, or the like. However, in such incompatible dissimilar material blends and alloys, adhesion at the phase interface becomes a problem.

  As such a composite material of fluororubber and silicone rubber, for example, in order to co-crosslink fluororubber and silicone rubber, a method of blending a silicone rubber containing a vinyl group and an iodine-containing fluoroelastomer (for example, a patent) Document 1) and a method of blending a fluorosilicone rubber containing a vinyl group and a bromine-containing fluoroelastomer (for example, see Patent Document 2) are known. However, the composite material obtained by these methods has a problem that the compression set is good but the tensile strength is not good.

  In addition, it is known that silicone rubber crosslinked particles generally used in cosmetics and the like are blended with fluororubber, and then the silicone crosslinked particles are modified with a fluoropropyl group or an epoxy group in order to improve compatibility. There is also a known method (for example, see Patent Document 3). However, Patent Document 3 is intended to improve the compatibility of the silicone crosslinked particles, and does not co-crosslink the fluororubber and the silicone crosslinked particles. Moreover, even if the tensile strength was improved, there was a problem in compression set.

  On the other hand, organic onium salts are useful for polyol-crosslinked fluororubbers and are well known among those skilled in the art. For example, Patent Document 4 discloses a fluoroelastomer composition containing an elastomer copolymer containing vinylidene fluoride and an organic onium salt. However, in Patent Document 4, an organic onium salt is used as a vulcanization accelerator, and the addition of an organic onium salt in an alloy or blend material with silicone rubber has not been studied.

  As a related technique of the present invention, it is known that an organic onium salt is used for adhesion and lamination of a fluoropolymer and a non-fluoropolymer (for example, see Patent Documents 5 and 6). However, in these patent documents, the fluoropolymer is dehydrofluorinated with an organic onium salt and bonded by reacting a nucleophile such as bisphenol AF. Therefore, a nucleophile such as bisphenol AF and an acid acceptor such as CaO are substantially essential components. Furthermore, the adhesive fluoropolymer compositions of these patent documents are not used alone as a blend / alloy material and have not been evaluated for sealing properties such as compression set.

Japanese Patent Laid-Open No. 55-50051 JP 56-501050 A JP-A-1-215847 JP 47-000191 A Special Table 2002-524305 EP 1454740

  An object of the present invention is to provide a peroxide crosslinking composition capable of providing a molded article having excellent fuel permeation resistance and excellent sealing properties.

  That is, the present invention relates to a peroxide crosslinking composition comprising (A) a peroxide-crosslinkable fluororubber, (B) a silicone rubber or a silicone raw rubber, and (C) an onium salt.

  (A) It is preferable that (B) component is 5-200 weight part and (C) component is 0.01-15 weight part with respect to 100 weight part of (A) component.

  The silicone rubber as the component (B) is preferably silicone rubber crosslinked particles obtained by crosslinking the silicone rubber composition.

  The (B) component silicone rubber crosslinked particles are preferably particles having an aliphatic unsaturated bond-containing group on a silicon atom in the rubber.

  The component (B) is preferably a rubber having a fluorine-containing monovalent hydrocarbon group on the silicon atom in the rubber.

  The component (C) is preferably a phosphonium salt.

  The present invention also relates to a molded article obtained by subjecting the peroxide crosslinking composition to peroxide crosslinking and a fuel-permeable sealing material.

  In the present invention, by using an onium salt, it is possible to improve not only the tensile strength of the resulting molded product but also a sealing property such as compression set.

  The present invention relates to a peroxide crosslinking composition comprising (A) a peroxide-crosslinkable fluororubber, (B) a silicone raw rubber or silicone rubber, and (C) an onium salt.

  Examples of the (A) component-peroxide-crosslinkable fluororubber used in the present invention include non-perfluorofluororubber (a) and perfluorofluororubber (b). In addition, perfluoro fluororubber means the thing which 90 mol% or more consists of a perfluoro monomer among the structural units.

  Examples of the non-perfluorofluororubber (a) include vinylidene fluoride (hereinafter referred to as VdF) -based fluororubber, tetrafluoroethylene (hereinafter referred to as TFE) / propylene-based fluororubber, TFE / propylene / VdF-based fluororubber, Examples include ethylene / hexafluoropropylene (hereinafter referred to as HFP) fluorine rubber, ethylene / HFP / VdF fluorine rubber, ethylene / HFP / TFE fluorine rubber, fluorosilicone fluorine rubber, or fluorophosphazene fluorine rubber. These can be used alone or in any combination as long as the effects of the present invention are not impaired.

  As the VdF-based fluororubber, those represented by the following general formula (1) are preferable.

-(M ¹ )-(M ² )-(N ¹ )-(1)
(In the formula, the structural unit M ¹ is a structural unit derived from VdF (m ¹ ), the structural unit M ² is a structural unit derived from a fluorine-containing ethylenic monomer (m ² ), and the structural unit N ¹ is a single unit. (It is a repeating unit derived from monomer (n ¹ ) copolymerizable with monomer (m ¹ ) and monomer (m ² ))

Among the VdF type fluorine-containing rubbers represented by the general formula (1), the structural unit M ¹ 30 to 85 mol%, preferably not containing a structural unit M ² 55-15 mol%, more preferably a structural unit M ¹ 50 80 mol%, the structural unit M ² 50 to 20 mol%. The structural unit N ¹ is preferably 0 to 20 mol% with respect to the total amount of the structural unit M ¹ and the structural unit M ² .

As the fluorine-containing ethylenic monomer (m ² ), one or more monomers can be used. For example, TFE, chlorotrifluoroethylene (hereinafter referred to as CTFE), trifluoroethylene, HFP, Fluorine-containing monomers such as fluoropropylene, tetrafluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutene, perfluoro (alkyl vinyl ether) (hereinafter referred to as PAVE), vinyl fluoride, and the like. Of these, TFE, HFP, and PAVE are preferable.

The monomer (n ¹ ) may be any monomer as long as it is copolymerizable with the monomer (m ¹ ) and the monomer (m ² ). For example, ethylene, propylene, alkyl vinyl ether, etc. can give.
The monomer (n ¹ ) is preferably a monomer that gives a cross-linked site.

As a monomer that gives such a crosslinking site, the general formula (2):
CY ¹ ₂ = CY ¹ −R _f ¹ CHR ¹ X ¹ (2)
Wherein Y ¹ is a hydrogen atom, a fluorine atom or —CH ₃ , and R _f ¹ is a fluoroalkylene group, a perfluoroalkylene group, a fluoropolyoxyalkylene group or a perfluoropolyoxyalkylene group, The perfluoroalkylene group may contain an etheric oxygen atom, R ¹ is a hydrogen atom or —CH ₃ , and X ¹ is an iodine atom or a bromine atom)
Iodine or bromine-containing monomer represented by the general formula (3):
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m (CF 2) n -X 2 (3)
(Wherein, m is an integer of 0 to 5, n is an integer of 1 to 3, X ² is a cyano group, a carboxyl group, an alkoxycarbonyl group, a bromine atom, an iodine atom)
A monomer represented by the general formula (4):
CH ₂ = CH (CF ₂ ) _p I (4)
(Wherein p is an integer of 1 to 10)
For example, perfluoro (6,6-dihydro-6-iodo-3-yl as described in JP-B-5-63482, JP-A-7-316234, and the like. Iodine-containing monomers such as oxa-1-hexene) and perfluoro (5-iodo-3-oxa-1-pentene), CF ₂ = CFOCF ₂ CF ₂ CH ₂ I described in JP-A-4-217936, etc. Iodine-containing monomers such as 4-iodo-3,3,4,4-tetrafluoro-1-butene described in JP-A-61-55138, A bromine-containing monomer described in JP-A-505341, a cyano group-containing monomer, a carboxyl group-containing monomer as described in JP-A-4-505345, and JP-A-5-500070, Such as alkoxycarbonyl group-containing monomers and the like. These can be used alone or in any combination.

  The iodine atom, bromine atom, vinyl group, cyano group, carboxyl group, and alkoxycarbonyl group can function as a crosslinking point.

  Specific examples of such VdF fluororubbers include VdF / HFP rubber, VdF / HFP / TFE rubber, VdF / CTFE rubber, VdF / CTFE / TFE rubber, and the like.

  As the TFE / propylene fluororubber, those represented by the following general formula (5) are preferable.

^{- (M 3) - (M} 4) - (N 2) - (5)
(In the formula, the structural unit M ³ is a structural unit derived from TFE (m ³ ), the structural unit M ⁴ is a structural unit derived from propylene (m ⁴ ), and the structural unit N ² is a monomer (m ³ ). And a repeating unit derived from the monomer (n ² ) copolymerizable with the monomer (m ⁴ )

Formula (5) Among the TFE / propylene type fluorine-containing rubbers represented by the structural unit M ³ 40 to 70 mol%, preferably not containing a structural unit M ⁴ 60 to 30 mol%, more preferably the structural unit M ³ In an amount of 50 to 60 mol% and the structural unit M ⁴ in an amount of 50 to 40 mol%. The structural unit N ² is preferably 0 to 40 mol% with respect to the total amount of the structural unit M ³ and the structural unit M ⁴ .

The monomer (n ² ) may be any monomer that can be copolymerized with the monomer (m ³ ) and the monomer (m ⁴ ). Is preferred. Examples thereof include VdF and ethylene.

  As the perfluoro fluorine rubber (b), those represented by the following general formula (6) are preferable.

^{- (M 5) - (M} 6) - (N 3) - (6)
(In the formula, the structural unit M ⁵ is a structural unit derived from TFE (m ⁵ ), the structural unit M ⁶ is a structural unit derived from PAVE or perfluoro (alkoxy vinyl ether) (m ⁶ ), and the structural unit N ³ is (It is a repeating unit derived from the monomer (m ³ ) and the monomer (n ³ ) copolymerizable with the monomer (m ⁶ ))

Among the perfluoro fluorine-containing rubbers represented by the general formula (6) (b), the structural unit M ⁵ 50 to 90 mol%, preferably not containing a structural unit M ⁶ 10 to 50 mol%, more preferably the structural unit M ⁵ 50 to 80 mol%, in which the structural unit M ⁶ 20 to 50 mol%. The structural unit N ³ is preferably 0 to 5 mol%, more preferably 0 to 2 mol%, based on the total amount of the structural unit M ⁵ and the structural unit M ⁶ . When the composition is out of the range, the properties as a rubber elastic body are lost, and the properties tend to be similar to those of a resin.

Examples of PAVE (m ⁶ ) include perfluoro (methyl vinyl ether) and perfluoro (propyl vinyl ether), and these can be used alone or in any combination.

As perfluoro (alkoxy vinyl ether) (m ⁶ ), for example, a monomer described in JP-A No. 61-223007 can be used.

The monomer (n ³ ) may be any monomer as long as it is copolymerizable with the monomer (m ⁵ ) and the monomer (m ⁶ ). preferable.

  Examples of the monomer that gives such a crosslinking site include VdF and the same ones as described above, and these can be used alone or in any combination.

  The iodine atom, bromine atom, vinyl group, cyano group, carboxyl group, and alkoxycarbonyl group can function as a crosslinking point.

  Specific examples of such perfluorofluororubber (b) are described in International Publication No. 97/24381 pamphlet, Japanese Examined Patent Publication No. 61-57324, Japanese Examined Patent Publication No. 4-81608, Japanese Patent Publication No. 5-13961. Fluoro rubber etc.

  Among these, the fluororubber is preferably a fluororubber composed of VdF and at least one other fluorine-containing monomer, such as VdF / HFP fluororubber, VdF / TFE / HFP fluororubber, and VdF / It is preferably at least one rubber selected from the group consisting of TFE / PAVE fluororubbers.

  The non-perfluorofluororubber (a) and the perfluorofluororubber (b) described above can be produced by a conventional method, but the obtained polymer has a narrow molecular weight distribution and is easy to control the molecular weight. A known iodine transfer polymerization method is preferred as a method for producing fluororubber because an iodine atom can be introduced into the terminal.

(B) component used by this invention is a silicone raw rubber or silicone rubber, and is not specifically limited. This silicone raw rubber is a linear polymer having a high degree of polymerization and having a linear or partially branched structure composed of diorganosiloxane units, which can be crosslinked with a curing agent to form a silicone rubber. Plasticity (25 ° C, 4.2 g spherical sample, 3 minutes later) of this raw silicone rubber by JIS K 6249: 2003 "Testing method for uncured and cured silicone rubber" specified by a parallel plate plasticity meter (William Plastometer) ) Is preferably in the form of a raw rubber having a value in the range of 100 to 200. Examples of the group bonded to the silicon atom of the silicone raw rubber include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, octyl group and decyl group; vinyl group, allyl group, Alkenyl groups such as butenyl, pentenyl, hexenyl, heptenyl and octenyl; aryl groups such as phenyl, tolyl, xylyl and naphthyl; aralkyl groups such as benzyl and phenethyl; At least part of the hydrogen atoms are substituted with chlorine, fluorine, cyano, etc., for example, substitution of chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, cyanoethyl, etc. Unsubstituted monovalent hydrocarbon group; alkylene group such as ethylene group, butylene group, pentylene group, hexylene group Epoxy-containing organic groups such as 3-glycidoxypropyl group, 2- (3,4-epoxycyclohexyl) ethyl group, 4-oxiranylbutyl group; 2-aminoethyl group, 3-aminopropyl group, N- ( Amino-containing organic groups such as 2-aminoethyl) -3-aminopropyl group; acrylic-containing organic groups such as 3-methacryloxypropyl group and 3-acryloxypropyl group; alkoxy groups such as methoxy group and ethoxy group; Examples include a hydrogen atom and a hydroxyl group. In particular, since the compatibility with the component (A) is good, the group bonded to the silicon atom of the silicone raw rubber is preferably a monovalent hydrocarbon group substituted with a fluorine atom such as a trifluoropropyl group. In particular, the general formula (7):
_{C m F 2m + 1 -C n} H 2n - (7)
(In the formula, m is an integer of 1 to 20, preferably 2 to 10, and n is an integer of 1 to 10.)
Or a group represented by the general formula (8):
^{_{R 2 -C m F 2m -C n}} H 2n - (8)
(In the formula, m is an integer of 1 to 20, preferably 2 to 10, R ² is an alkyl group, an alkenyl group, or an aryl group, and n is an integer of 1 to 10.)
It is preferable that it is group represented by these. In addition, since the crosslinking reaction by the peroxide crosslinking agent and peroxide crosslinking aid used in the present invention is possible, the group bonded to the silicon atom in the silicone raw rubber is the alkenyl group; the acrylic-containing organic group, etc. The aliphatic unsaturated bond-containing group is preferable.

  Examples of such silicone raw rubber include molecular chain both ends trimethylsiloxy group-capped dimethylpolysiloxane raw rubber, molecular chain both ends silanol group-capped dimethylpolysiloxane raw rubber, molecular chain both ends trimethylsiloxy group-capped dimethylsiloxane / methylvinylsiloxane copolymer Raw rubber, molecular chain both ends silanol-blocked dimethylsiloxane / methylvinylsiloxane copolymer raw rubber, molecular chain both ends trimethylsiloxy group-blocked dimethylsiloxane / methyl (3,3,3-trifluoropropyl) siloxane copolymer raw rubber, molecule Silanol group-blocked dimethylsiloxane methyl (3,3,3-trifluoropropyl) siloxane copolymer raw rubber, molecular chain both ends trimethylsiloxy group blocked dimethylsiloxane methylvinylsiloxane methyl (3,3,3- bird (Rolopropyl) siloxane copolymer raw rubber, molecular chain both ends silanol-blocked dimethylsiloxane / methylvinylsiloxane / methyl (3,3,3-trifluoropropyl) siloxane copolymer raw rubber, molecular chain both ends trimethylsiloxy group-blocked dimethylsiloxane Examples include methyl phenylsiloxane copolymer raw rubber and molecular chain both-end silanol-blocked dimethylsiloxane / methylphenylsiloxane copolymer raw rubber.

Such silicone raw rubber may contain a reinforcing material such as silica fine powder and an auxiliary agent such as silane and low-molecular siloxane for dispersing the same. Examples of the reinforcing material include fumed silica fine powder, fused silica fine powder, precipitated silica fine powder, and fumed titanium oxide fine powder. Particularly, fumed silica fine powder having a BET specific surface area of at least 50 m ² / g. A powder is preferred. As auxiliary agents, alkoxysilanes such as methyltrimethoxysilane and vinyltrimethoxysilane; chlorosilanes such as methyltrichlorosilane and vinyltrichlorosilane; silazanes such as hexamethyldisilazane; dimethylsiloxane oligomers blocked with silanol groups at both ends of the molecular chain Examples thereof include siloxane oligomers such as silanol group-capped methylvinylsiloxane oligomers at both molecular chain ends and methylphenylsiloxane oligomers capped at both molecular chain terminals.

  On the other hand, the silicone rubber is preferably a silicone rubber crosslinked particle obtained by crosslinking a silicone rubber composition. The shape of the silicone rubber cross-linked particles is not particularly limited, and examples thereof include a spherical shape and an indefinite shape, and in particular, a spherical shape is preferable because it can be uniformly dispersed in the component (A). The group which couple | bonds with the silicon atom of this silicone rubber crosslinked particle is not specifically limited, Specifically, the group similar to the above is illustrated. In particular, in the present invention, since the component (A) forms a continuous phase and the crosslinked silicone rubber particles form a dispersed phase, a cured product having excellent fuel barrier properties can be formed. The group bonded to is preferably a monovalent hydrocarbon group substituted with the fluorine atom. In addition, since the crosslinking reaction with the peroxide crosslinking agent and peroxide crosslinking aid used in the present invention is possible, the group bonded to the silicon atom in the rubber of the silicone rubber crosslinked particles is the alkenyl group; An aliphatic unsaturated bond-containing group such as a containing organic group is preferred, and a 3-methacryloxypropyl group is particularly preferred from the viewpoint that it can easily undergo a co-crosslinking reaction with the component (A) by a peroxide crosslinking agent and a peroxide crosslinking aid.

  The average particle diameter of such silicone rubber crosslinked particles is not particularly limited, but is preferably 100 μm or less, more preferably 0.01 to 50 μm, still more preferably 0.01 to 20 μm, It is particularly preferable that the thickness is from 1 to 10 μm. This is because it tends to be difficult to produce crosslinked particles having an average particle diameter of less than 0.01 μm, and when it exceeds 100 μm, the mechanical strength of the fluororubber blended with this tends to decrease. .

  As a method for producing such crosslinked particles, for example, a liquid silicone rubber composition is dispersed in water according to the method described in JP-A-62-243621 or JP-A-63-202658. The method of curing this composition is preferred.

Examples of the liquid silicone rubber composition used in this production method include organopolysiloxane having at least two silicon atom-bonded hydroxyl groups in one molecule, and general formula (9):
R ³ _a Si (OR ⁴ ) _(4-a) (9)
(Wherein R ³ is a substituted or unsubstituted monovalent hydrocarbon group excluding an alkenyl group, R ⁴ is an alkyl group having 4 or less carbon atoms, and a is 0, 1 or 2.)
Or a partially hydrolyzed condensate thereof and / or an organohydrogenpolysiloxane, a condensation reaction catalyst, and, if necessary, a condensation-reactive composition (hereinafter referred to as composition ( I)), and an organopolysiloxane having at least two alkenyl groups in one molecule, an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule, and an addition reaction catalyst And an addition-reactive composition (hereinafter referred to as composition (II)).

  In particular, from the viewpoint of affinity with fluororubber, crosslinked particles obtained by curing the composition (I) are preferable.

  Below, composition (I) and (II) are demonstrated.

  In the composition (I), the organopolysiloxane is a main ingredient and has at least two silicon atom-bonded hydroxyl groups in one molecule. The bonding position of the hydroxyl group is not limited, but is preferably a molecular chain terminal from the viewpoint of good reactivity.

  Other groups bonded to the silicon atom include methyl groups, ethyl groups, propyl groups, butyl groups, pentyl groups, hexyl groups, cyclohexyl groups, octyl groups, decyl groups and other alkyl groups; vinyl groups, allyl groups, butenyl groups. , Pentenyl group, hexenyl group, heptenyl group, octenyl group and other alkenyl groups; phenyl group, tolyl group, xylyl group, naphthyl group and other aryl groups; benzyl group, phenethyl group and other aralkyl groups; and hydrogen atoms of these groups At least a part of which is substituted by a chlorine atom, a fluorine atom, a cyano group, or the like, for example, an unsubstituted or substituted chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group, cyanoethyl group, etc. Monovalent hydrocarbon group; alkoxy group such as methoxy group, ethoxy group and the like. Among these, methyl group, phenyl Group, 3,3,3-trifluoropropyl group are preferred.

  Examples of the molecular structure of the organopolysiloxane include linear, cyclic, network, partially branched linear, and branched, with linear being particularly preferred.

  The viscosity of the organopolysiloxane at 25 ° C. is not particularly limited, but is practically preferably 5 to 100,000 mPa · s, more preferably 10 to 10,000 mPa · s.

  Next, the organosilicon compound represented by the general formula (9) or a partially hydrolyzed condensate thereof is a crosslinking agent component.

In the formula, R ³ is an unsubstituted or substituted monovalent hydrocarbon group excluding an alkenyl group, such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, octyl group, decyl group, etc. An aryl group such as a phenyl group, a tolyl group, a xylyl group or a naphthyl group; an aralkyl group such as a benzyl group or a phenethyl group; and at least a part of hydrogen atoms of these groups are a chlorine atom, a fluorine atom or a cyano group Examples thereof include chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group, and cyanoethyl group.

In the formula, R ⁴ is an alkyl group having 4 or less carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. Among these, as R ⁴ , a methyl group is preferable.

  In the formula, a is 0, 1 or 2, and preferably 0 or 1.

  Examples of such organosilicon compounds or partial hydrolysis condensates thereof include methyltrimethoxysilane, ethyltrimethoxysilane, phenyltrimethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, tetramethoxysilane, and tetraethoxy. Examples thereof include silane, methyl polysilicate, and ethyl polysilicate.

  The amount of the organosilicon compound or the partial hydrolysis condensate thereof is not particularly limited, but is preferably 0.1 to 50 parts by weight, for example, 1 to 40 parts by weight with respect to 100 parts by weight of the organopolysiloxane. It is more preferable that If the compounding amount of the organosilicon compound or its partially hydrolyzed condensate is less than the lower limit of the above range, crosslinking tends not to proceed sufficiently. This is because the mechanical strength of the particles tends to decrease significantly.

  Organohydrogenpolysiloxane is a crosslinking agent component and is not particularly limited as long as it has silicon-bonded hydrogen atoms. The bonding position of the silicon atom-bonded hydrogen atom is not limited, and examples thereof include a molecular chain terminal and / or a molecular chain side chain. Other groups bonded to the silicon atom include methyl groups, ethyl groups, propyl groups, butyl groups, pentyl groups, hexyl groups, cyclohexyl groups, octyl groups, decyl groups, and other alkyl groups; phenyl groups, tolyl groups, xylyl groups. Aryl groups such as naphthyl group; aralkyl groups such as benzyl group and phenethyl group; and at least part of hydrogen atoms of these groups are substituted with chlorine atom, fluorine atom, cyano group, etc., for example, chloromethyl group, Examples thereof include unsubstituted or substituted hydrocarbon groups excluding alkenyl groups such as 3-chloropropyl group, 3,3,3-trifluoropropyl group, and cyanoethyl group. Among these, methyl group, phenyl group, 3,3, A 3-trifluoropropyl group is preferred.

  Examples of the molecular structure of the organohydrogenpolysiloxane include linear, cyclic, network, partially branched linear, and branched, with linear being particularly preferred.

  Further, the viscosity of the organohydrogenpolysiloxane at 25 ° C. is not particularly limited, but is practically preferably 1 to 10,000 mPa · s, and more preferably 1 to 1,000 mPa · s.

  Examples of such organohydrogenpolysiloxanes include trimethylsiloxy group-capped methylhydrogen polysiloxanes at both molecular chain ends, trimethylsiloxy group-capped dimethylsiloxane / methylhydrogensiloxane copolymers with both molecular chain terminals, and dimethylhydrol. Examples thereof include gensiloxy group-capped methylhydrogen polysiloxane and dimethylhydrogensiloxy group-capped dimethylsiloxane / methylhydrogensiloxane copolymer at both ends of the molecular chain.

  Although the compounding quantity of this organohydrogenpolysiloxane is not specifically limited, For example, it is preferable that it is 1-20 weight part with respect to 100 weight part of organopolysiloxane. If the amount of the organohydrogenpolysiloxane is less than the lower limit of the above range, crosslinking tends not to proceed sufficiently. On the other hand, if the amount exceeds the upper limit of the above range, the mechanical strength of the resulting crosslinked particles This is because there is a tendency to decrease significantly.

  The catalyst for the condensation reaction is a catalyst for accelerating the curing of the composition (I). For example, di-n-butyltin diacetate, di-n-butyltin di-2-ethylhexoate, n- Tin series such as butyltin tri-2-ethylhexoate, di-n-butyltin dilaurate, di-n-butyltin dioctoate, tin octylate, tin octenoate, tin laurate, tin naphthenate, tin oleate Catalyst: Organic titanate compound such as tetra-n-butyl titanate, tetraisopropyl titanate, tetra-2-ethylhexyl titanate, ethylene glycol titanate; diisopropoxybis (acetylacetone) titanium, diisopropoxybis (ethyl acetoacetate) titanium , Diisopropoxybis (methyl acetoacetate) titanium, dimethoxybis (methyl acetoacetate) titanium, Titanium catalysts such as butoxybis (ethyl acetoacetate) titanium and titanium naphthenate; ferric stanooctenoate, lead octenoate, lead laurate, zinc oxalate, cobalt naphthenate, iron naphthenate, zinc naphthenate, zinc stearate , Organic acid salt catalysts of metals such as iron octenoate and lead octenoate; amine catalysts such as n-hexylamine and guanidine; chloroplatinic acid, chloroplatinic acid alcohol solution, platinum olefin complex, platinum alkenylsiloxane Examples thereof include platinum-based catalysts such as complexes, platinum black, and platinum-supported silica, or mixtures of two or more of these condensation reaction catalysts.

  The blending amount of the catalyst for the condensation reaction is not particularly limited, but is preferably 0.01 to 20 parts by weight, more preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the organopolysiloxane.

Further, in the composition (I), an alkenyl group, an epoxy-containing organic group, an amino-containing organic group, and an acrylic-containing organic group are introduced into the resulting crosslinked particles, so that the general formula (10):
R ⁵ R ³ _b Si (OR ⁴ ) _(3-b) (10)
Or a partially hydrolyzed condensate thereof may be blended.

In the formula, R ³ is an unsubstituted or substituted monovalent hydrocarbon group excluding an alkenyl group, R ⁴ is an alkyl group having 4 or less carbon atoms, and examples thereof are the same as those described above.
In the formula, R ⁵ is a group selected from the group consisting of an alkenyl group, an epoxy-containing organic group, an amino-containing organic group, and an acrylic-containing organic group. Examples of the alkenyl group include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, and an octenyl group. Examples of the epoxy-containing organic group include a 3-glycidoxypropyl group, 2- (3,4) -Epoxycyclohexyl) ethyl group, 4-oxiranylbutyl group are exemplified, and amino-containing organic groups include 2-aminoethyl group, 3-aminopropyl group, N- (2-aminoethyl) -3-aminopropyl Examples of the acryl-containing organic group include a 3-methacryloxypropyl group and a 3-acryloxypropyl group. Among these, an alkenyl group and an acryl-containing organic group are preferable because they have reactivity in the peroxide crosslinking reaction of fluororubber, and a vinyl group, an allyl group, a hexenyl group, and a 3-methacryloxypropyl group are more preferable.
B is 0 or 1.

  Examples of such organosilicon compounds or partial hydrolysates thereof include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, methylvinyldimethoxysilane, allyltrimethoxysilane, and 3-glycidide. Xylpropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, N- ( 2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, partial hydrolysis condensates of these organosilicon compounds, or mixtures of two or more of these.

  The amount of the organosilicon compound or its partial hydrolyzate is not particularly limited, but is preferably 0.05 to 50 parts by weight, and 0.05 to 15 parts by weight with respect to 100 parts by weight of the organopolysiloxane. It is more preferable. This is because if the amount of the organosilicon compound or its partial hydrolyzate is less than the lower limit of the above range, the reactivity of the resulting crosslinked particles to the fluororubber cannot be expected, while the upper limit of the above range. This is because the mechanical strength of the resulting crosslinked particles tends to be significantly reduced.

  Next, composition (II) is demonstrated.

  In the composition (II), the organopolysiloxane is a main ingredient and has at least two alkenyl groups in one molecule.

  Examples of the alkenyl group include a vinyl group, an allyl group, a butenyl group, a pentenyl group, and a hexenyl group, and a vinyl group is preferable.

  Examples of other groups bonded to the silicon atom include unsubstituted or substituted hydrocarbon groups, epoxy-containing organic groups, amino-containing organic groups, and acrylic-containing organic groups. Specific examples of these groups include those described as other groups bonded to silicon atoms in the siloxane units constituting the crosslinked particles. Among these, a methyl group and a phenyl group are preferable.

  Examples of the molecular structure of the organopolysiloxane include linear, cyclic, network, partially branched linear, and branched, preferably linear.

  The viscosity of the organopolysiloxane at 25 ° C. is not limited, but is practically preferably 5 to 100,000 mPa · s, and more preferably 20 to 10,000 mPa · s.

  Organohydrogenpolysiloxane is a cross-linking agent and is characterized by having at least two silicon-bonded hydrogen atoms in one molecule. Examples of the other group bonded to the silicon atom include the same unsubstituted or substituted hydrocarbon groups as described above, and among them, a methyl group and a phenyl group are preferable.

  Examples of the molecular structure of the organohydrogenpolysiloxane include linear, cyclic, network, partially branched linear, and branched, with linear being preferred.

  The viscosity of the organohydrogenpolysiloxane at 25 ° C. is not limited, but is practically preferably 1 to 10,000 mPa · s, and more preferably 1 to 1,000 mPa · s.

  The compounding amount of the organohydrogenpolysiloxane is not particularly limited, but is preferably 0.05 to 50 parts by weight, more preferably 0.05 to 15 parts by weight with respect to 100 parts by weight of the organopolysiloxane. . This is because when the amount of the organohydrogenpolysiloxane is less than the lower limit of the above range, it tends to be difficult to obtain crosslinked particles. On the other hand, when the amount exceeds the upper limit of the above range, the resulting crosslinked particles are obtained. There is a tendency that the mechanical strength of the steel significantly decreases.

  The catalyst for addition reaction is a catalyst for accelerating the curing of the composition (II). For example, chloroplatinic acid, chloroplatinic acid alcohol solution, platinum olefin complex, platinum alkenylsiloxane complex, platinum black, platinum Examples thereof include platinum-based catalysts such as supported silica.

  The amount of the addition reaction catalyst is not particularly limited, but is preferably 0.01 to 500 ppm, for example, 0.1 to 100 ppm in terms of the weight of the catalyst metal in the catalyst with respect to the organopolysiloxane. It is more preferable that

  The silicone rubber crosslinked particles used in the present invention can be obtained by dispersing and curing these liquid silicone rubber compositions in water. It is preferred to use a surfactant to disperse this composition in water to form a stable granulate.

  Examples of the surfactant include nonionic surfactants such as polyoxyalkylene alkyl ether, polyoxyalkylene alkylphenol ether, polyoxyalkylene alkyl ester, polyoxyalkylene sorbitan ester, and ethylene oxide adduct of diethylene glycol trimethylnonanol; alkylbenzene Anionic surfactants such as sulfonate, alkyl sulfate, polyoxyethylene alkyl ether sulfate; octyltrimethylammonium hydroxide, dodecyltrimethylammonium hydroxide, hexadecyltrimethylammonium hydroxide, octyldimethylbenzylammonium hydroxide, decyl Dimethylbenzylammonium hydroxide, dioctadecyldimethylammonium Rokishido, cationic surfactants such as coconut oil trimethylammonium hydroxide, or a mixture of two or more of these surfactants.

  In addition, these liquid silicone rubber compositions are dispersed in water to form crosslinked particles having a small average particle size. For example, conventional colloid mills, homogenizers, propeller-type agitators, combimixes, ultrasonic agitators, etc. A known emulsifier can be used.

  Next, by curing the liquid silicone rubber composition particles dispersed in water to form silicone rubber crosslinked particles, this aqueous dispersion can be left at room temperature or heated. However, these conditions can adopt the conditions normally used.

  Methods for separating the crosslinked particles from the aqueous dispersion include, for example, a method of drying in an oven, a method of drying with cold air, hot air or hot air, a method of drying under reduced pressure, and a volatile organic material such as alcohol. An example is a method in which a solvent is added to replace water, followed by drying by the above method. As these conditions, conditions that are usually used can be adopted.

  The amount of component (B) added is preferably 5 to 200 parts by weight, more preferably 30 to 180 parts by weight, and 70 to 160 parts by weight with respect to 100 parts by weight of component (A). Is more preferable. If the amount of component (B) added is less than the lower limit of the above range, the cold resistance of the cured product obtained is insufficiently improved. On the other hand, if the amount exceeds the upper limit of the above range, the resistance of the cured product obtained is insufficient. This is because fuel permeability and mechanical properties tend to be extremely lowered.

  In the present invention, by using the onium salt of the component (C), it is possible to improve not only the tensile strength of the obtained molded product but also the sealing properties such as compression set. The reason is that the use of the onium salt promotes adhesion at the phase interface between the incompatible fluororubber and the silicone rubber, or co-crosslinking between the fluororubber and the silicone rubber. Conceivable.

  The onium salt used in the present invention is not particularly limited. For example, ammonium compounds such as quaternary ammonium salts, phosphonium compounds such as quaternary phosphonium salts, arsonium compounds, stibonium compounds, oxonium compounds, sulfonium compounds, and selenonium compounds. , Stannonium compounds, iodonium compounds, cyclic amines, monofunctional amine compounds, and the like.

  The quaternary ammonium salt is not particularly limited. For example, 8-methyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8-methyl-1,8-diazabicyclo [5, 4,0] -7-undecenium iodide, 8-methyl-1,8-diazabicyclo [5,4,0] -7-undecenium hydroxide, 8-methyl-1,8-diazabicyclo [5 , 4,0] -7-Undecenium methyl sulfate, 8-ethyl-1,8-diazabicyclo [5,4,0] -7-undecenium bromide, 8-propyl-1,8-diazabicyclo [5 , 4,0] -7-undecenium bromide, 8-dodecyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8-dodecyl-1,8-diazabicyclo 5,4,0] -7-undecenium hydroxide, 8-eicosyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8-tetracosyl-1,8-diazabicyclo [ 5,4,0] -7-undecenium chloride, 8-benzyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride (hereinafter referred to as DBU-B), 8-benzyl -1,8-diazabicyclo [5,4,0] -7-undecenium hydroxide, 8-phenethyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8- ( 3-phenylpropyl) -1,8-diazabicyclo [5,4,0] -7-undecenium chloride.

  The quaternary phosphonium salt is not particularly limited. For example, tetrabutylphosphonium chloride, benzyltriphenylphosphonium chloride (hereinafter referred to as BTPPC), tetraphenylphosphonium chloride (TPPC), benzyltrimethylphosphonium chloride, benzyltributylphosphonium. Examples thereof include chloride, tributylallylphosphonium chloride, tributyl-2-methoxypropylphosphonium chloride, benzylphenyl (dimethylamino) phosphonium chloride and the like.

  Among these onium salts, a phosphonium salt is preferable because it is relatively stable in the presence of most inorganic bases, has a relatively low hygroscopic property, and has little coloration of a rubber molded product at the time of crosslinking. Furthermore, BTPPC is preferable from the viewpoint of heat resistance of the fluororubber / silicone rubber alloy.

  The amount of component (C) added is preferably 0.01 to 15 parts by weight, more preferably 0.05 to 5 parts by weight, and more preferably 0.1 to 100 parts by weight of component (A). More preferably, it is ˜1 part by weight. If the amount of component (B) added is less than the lower limit of the above range, the crosslinking promoting effect tends not to be sufficiently obtained. On the other hand, if the amount exceeds the upper limit of the above range, the mechanical properties of the cured product obtained This is because it tends to deteriorate or the heat resistance deteriorates.

  The peroxide crosslinking agent used in the present invention is not particularly limited as long as it is usually used.

  As the peroxide cross-linking agent, in general, one that easily generates a peroxy radical in the presence of heat or a redox system is preferable. Specifically, 1,1-bis (t-butylperoxy) -3,5,5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-butylperoxide, To t-butylcumyl peroxide, dicumyl peroxide, α, α′-bis (t-butylperoxy) -p-diisopropylbenzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) Xanthine, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, benzoyl peroxide, t-butylperoxybenzene, 2,5-dimethyl-2,5-di (benzoylperoxy) ) Hexane, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, and the like. Among these, a dialkyl type is preferable. In general, in consideration of the amount of active —O—O—, decomposition temperature and the like, the kind and amount of peroxide used are selected.

  In addition, a crosslinking aid can be used as necessary. Examples of the crosslinking aid include triallyl cyanurate, triallyl isocyanurate (TAIC), triacryl formal, triallyl trimellitate, N, N′-m. -Phenylene bismaleimide, dipropargyl terephthalate, diallyl phthalate, tetraallyl terephthalamide, triallyl phosphate and the like. Among these, triallyl isocyanurate (TAIC) is preferable from the viewpoint of crosslinkability and physical properties of the cross-linked product.

  As a compounding quantity of a peroxide crosslinking agent, it is preferable that it is 0.05-10 weight part with respect to 100 weight part of (A) component, and it is more preferable that it is 1.0-5 weight part. If the blending amount of the cross-linking agent is less than the lower limit of the above range, the cross-linking of the fluororubber does not proceed sufficiently, and the resulting molded article tends to have a reduced fuel permeability. If the upper limit is exceeded, the hardness of the resulting molded product tends to be too high.

  As a compounding quantity of a crosslinking adjuvant, it is preferable that it is 0.1-10 weight part with respect to 100 weight part of (A) component, and it is more preferable that it is 0.5-5 weight part. If the blending amount of the crosslinking aid is less than the lower limit of the above range, the crosslinking of the fluororubber does not proceed sufficiently and the resulting molded article tends to have poor fuel permeation resistance. This is because the moldability tends to decrease if the upper limit of the above is exceeded.

  In addition to a crosslinking agent and a crosslinking aid, a normal additive as required, for example, a filler such as calcium hydroxide, magnesium hydroxide, silica, quartz, alumina, calcium oxide, magnesium oxide; processing aid, plasticity An agent, a colorant, an antioxidant, an anti-aging agent, an ozone deterioration agent, an ultraviolet absorber, etc. can be blended, and one or more conventional crosslinking agents and crosslinking aids different from those mentioned above can be blended. Alternatively, each component can be prepared by mixing using an ordinary elastomer processing machine such as an open roll, a Banbury mixer, a kneader or the like. The peroxide crosslinking composition thus obtained is crosslinked and molded according to a conventional method. That is, it is molded by compression molding, injection molding, extrusion molding, calendar molding, dip molding, coating, etc. by dissolving in a solvent.

  The crosslinking conditions vary depending on the molding method and the shape of the molded product, but are generally in the range of several seconds to 5 hours at 100 ° C to 300 ° C. Further, secondary crosslinking may be performed in order to stabilize the physical properties of the crosslinked product. The secondary crosslinking conditions are 150 ° C. to 300 ° C. and about 30 minutes to 48 hours.

  In addition, in the molded article formed from the peroxide crosslinking composition of the present invention, it is preferable that the fluororubber forms a continuous phase and the silicone rubber forms a dispersed phase from the viewpoint of realizing excellent fuel barrier properties. .

  In addition, the molded article of the present invention includes a co-continuous structure of fluororubber and silicone rubber in a part of the structure in which fluororubber which is a preferred form forms a continuous phase and silicone rubber forms a dispersed phase. You can leave.

  Furthermore, the present invention relates to a molded article obtained by subjecting the peroxide crosslinking composition of the present invention to peroxide crosslinking, and a fuel-permeable sealing material. And a laminated structure having a layer formed from the peroxide crosslinking composition of the present invention and a layer formed from other materials.

  In a laminated structure of at least one layer formed from the peroxide crosslinking composition of the present invention and at least one layer formed from another material, the other material is expected to have the required properties. What is necessary is just to select an appropriate thing according to a use. Examples of the other materials include polyolefin (eg, high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, ethylene-propylene copolymer, polypropylene, etc.), nylon, polyester, vinyl chloride resin. (PVC), thermoplastic polymers such as vinylidene chloride resin (PVDC), cross-linked rubbers such as ethylene-propylene-diene rubber, butyl rubber, nitrile rubber, silicone rubber, acrylic rubber, metal, glass, wood, ceramic, etc. it can.

  In the molded article having the laminated structure, an adhesive layer may be interposed between a layer formed from the peroxide crosslinking composition of the present invention and a base material layer formed from another material. By interposing the adhesive layer, the layer formed from the peroxide crosslinking composition of the present invention and the base material layer formed from other materials can be firmly joined and integrated. Examples of the adhesive used in the adhesive layer include acid anhydride-modified products of diene polymers; acid anhydride-modified products of polyolefins; polymer polyols (for example, glycol compounds such as ethylene glycol and propylene glycol, and adipic acid) Polyester polyol obtained by polycondensation of a dibasic acid, a partially saponified product of a copolymer of vinyl acetate and vinyl chloride, and a polyisocyanate compound (for example, a glycol compound such as 1,6-hexamethylene glycol) A reaction product of a molar ratio of 1 to 2 with a diisocyanate compound such as 2,4-tolylene diisocyanate; a molar ratio of a triol compound such as trimethylolpropane and a diisocyanate compound such as 2,4-tolylene diisocyanate of 1: 3 Reaction products etc.), etc. can be usedFor forming the laminated structure, a known method such as co-extrusion, co-injection, or extrusion coating can also be used.

  The peroxide crosslinking composition of the present invention, and a molded product and a fuel-permeable sealing material using the composition are, for example, a semiconductor manufacturing apparatus, a liquid crystal panel manufacturing apparatus, a plasma panel manufacturing apparatus, a plasma address liquid crystal panel, a field Semiconductor related fields such as emission display panels and solar cell substrates; automotive field; aircraft field; rocket field; ship field; chemical field such as plant; pharmaceutical field such as pharmaceutical; photographic field such as developing machine; printing such as printing machine Field: Painting field such as coating equipment; Analytical / physical chemical field; Food plant equipment field; Nuclear power plant equipment field; Steel field such as iron plate processing equipment; General industrial field; Electric field; Fuel cell field Of these, among these, it can be more suitably used in the automobile field.

  In the automotive field, gaskets, shaft seals, valve stem seals, sealing materials and hoses can be used for engines and peripheral devices, hoses and sealing materials can be used for AT devices, O (square) rings, tubes, packings. The valve core material, hose, sealing material and diaphragm can be used for fuel systems and peripheral devices. Specifically, engine head gasket, metal gasket, oil pan gasket, crankshaft seal, camshaft seal, valve stem seal, manifold packing, oil hose, oxygen sensor seal, ATF hose, injector O-ring, injector packing, fuel Pump O-ring, diaphragm, fuel hose, crankshaft seal, gear box seal, power piston seal, cylinder liner seal, valve stem seal, automatic transmission front pump seal, rear axle pinion seal, universal joint gasket, speed Meter pinion seal, foot brake piston cup, torque transmission O-ring, oil seal, exhaust gas reburner seal, bearing Lumpur, EGR tubes, Tsuinkyabu tube, the sensor diaphragm of the carburetor, rubber vibration isolator (engine mount, exhaust part, etc.), afterburners hoses, can be used as an oxygen sensor bush.

  The molded article of the present invention can be suitably used for the various applications described above, and is particularly suitable as a fuel peripheral part.

  Next, the present invention will be described with reference to examples, but the present invention is not limited to such examples. In addition, various rubber physical properties of the obtained crosslinked molded product were tested by the following methods.

<Tensile test>
In accordance with JIS K 6251, the tensile stress at break (TSb) and the elongation at break (Eb) were determined. The test piece was dumbbell-shaped No. 4.

<Hardness>
Based on JIS K 6253, the type A durometer hardness ( _HA ) was determined.

<Compression set>
Based on JIS K 6262, it was determined under the conditions of a compression strain of 25%, a test temperature of 150 ° C. (or 175 ° C., 200 ° C.) and a test time of 70 hours. The test piece used was a ring (P24). Moreover, the sample piece used for the compression set test (70h, 150 degreeC) was observed, and the presence or absence of coloring after a heating was determined.

<Cold resistance>
Based on JIS K 6261, it evaluated by the low-temperature elastic recovery test (TR test). It was expressed as a temperature (TR10) at which the shrinkage rate becomes 10%.

<Fuel permeability>
The weight was determined by a permeation cup gravimetric method with reference to ASTM E 96. CE10 (isooctane 45 vol%, toluene 45 vol%, ethanol 10 vol%) was used as the fuel oil and measured at 40 ° C. The fuel permeability (g · mm / m ² · day) was calculated by converting the sample thickness and area according to the following equation after the permeation rate reached a steady state.

  The materials used in Examples and Comparative Examples are shown below.

<Fluorine rubber>
An autoclave made of SUS316 with an internal volume of 3 L is charged with 1.0 L of pure water, 2.0 g of C ₇ F ₁₅ COONH ₄ as an emulsifier, and 0.09 g of disodium hydrogen phosphate 12-hydrate as a pH adjuster, and the system is filled with nitrogen gas Then, the temperature was raised to 80 ° C. while stirring at 600 rpm, and a monomer mixture (molar ratio 70/5/25) of VdF / TFE / perfluoro (methyl vinyl ether) (hereinafter referred to as PMVE) was internal pressure. Was press-fitted so as to be 1.57 MPa. Next, 4 mL of a 5 mg / mL aqueous solution of ammonium persulfate (hereinafter referred to as APS) was injected under nitrogen pressure to initiate the reaction.

Since the pressure decreases with the progress of the polymerization reaction, when the pressure decreases to 1.47 MPa, 1.2 g of I (CF ₂ ) ₄ I, which is a diiodine compound, is injected and then I (CF ₂ ) ₄ I 1 .2 g was repressurized to 1.57 MPa with a monomer mixture (molar ratio 75/7/18), and the reaction was continued by injecting 2 mL of the APS aqueous solution with nitrogen gas every 3 hours while repeating the pressure increase and decrease.

When the total pressure drop from the start of the polymerization reaction reaches 2.55 MPa (after 5 hours), 1.8 g of iodine-containing fluorinated vinyl ether ICH ₂ CF ₂ CF ₂ OCF = CF ₂ (hereinafter referred to as IM) is injected. did. Similarly, when the total pressure drop reached 5.10 MPa (after 5 hours), the autoclave was cooled to release the unreacted monomer to obtain an aqueous emulsion having a solid content concentration of 29.9% by weight.

To this aqueous emulsion, a 5% by weight potassium alum solution was added for coagulation, and the coagulated product was washed with water and dried to obtain 400 g of a rubbery polymer. The Mooney viscosity (ML1 + 10 (100 ° C.)) of this polymer was 73. As a result of ¹⁹ F-NMR analysis, it was found that the monomer unit composition of this polymer was VdF / TFE / PMVE / IM = 73.9 / 7.0 / 19.0 / 0.1 (mol%). .

<Onium salt>
8-Benzyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride (DBU-B)
Benzyltriphenylphosphonium chloride (BTPPC)
Tetraphenylphosphonium chloride (TPPC)

<Crosslinking agent>
2,5-Dimethyl-2,5-di (t-butylperoxy) hexane (Perhexa 25B)

<Co-crosslinking agent (crosslinking aid)>
Triallyl isocyanurate (TAIC)

<Silicone rubber (raw rubber) (SR1)>
Plasticity (25 ° C., 4.2 g) by a parallel plate plasticity meter (William Plastometer) as defined by SE1185U (JIS K 6249: 2003 “Testing method for uncured and cured silicone rubber”) manufactured by Toray Dow Corning Co., Ltd. Spherical sample, 3 minutes later) Compound consisting of a trimethylsiloxy group-capped dimethylsiloxane / methylvinylsiloxane copolymer raw rubber having a value of 158 and a fumed silica fine powder having a BET specific surface area of 200 m ² / g)

<Silicon rubber crosslinked product particles>
Synthesis Example 1 (Preparation of spherical silicone rubber powder (SR2))
Average formula: 86.4 parts by weight of dimethylpolysiloxane represented by HO [(CH ₃ ) ₂ SiO] ₄₅ H, average formula: (CH ₃ ) ₃ SiO [(CH ₃ ) HSiO] ₄₀ Si (CH ₃ ) ₃ 9.1 parts by weight of a methylhydrogenpolysiloxane blocked with a trimethylsiloxy group at both ends of a molecular chain and 4.3 parts by weight of 3-glycidoxypropyltrimethoxysilane were uniformly mixed. Next, this mixture is dispersed in an aqueous solution composed of 5 parts by weight of polyoxyethylene lauryl ether and 100 parts by weight of pure water, and further uniformly emulsified by a colloid mill, and then diluted by adding 158 parts by weight of pure water for condensation. An emulsion of a reactive crosslinkable silicone composition was prepared.

  Next, this emulsion was mixed with a condensation reaction catalyst prepared by dispersing 1 part by weight of tin (II) octylate in an aqueous solution consisting of 1 part by weight of polyoxyethylene lauryl ether and 9 parts by weight of pure water. After standing for 1 day, moisture was removed by a hot air dryer at 300 ° C. to prepare spherical silicone rubber powder (SR2) (average particle size: 2.0 μm).

Synthesis Example 2 (Preparation of spherical silicone rubber powder (SR3))
Average formula: 88.0 parts by weight of dimethylpolysiloxane represented by HO [(CH ₃ ) ₂ SiO] ₄₅ H, average formula: (CH ₃ ) ₃ SiO [(CH ₃ ) HSiO] ₄₀ Si (CH ₃ ) ₃ 9.3 parts by weight of a methyl hydrogen polysiloxane blocked with a trimethylsiloxy group at both ends of a molecular chain and 2.7 parts by weight of vinyltrimethoxysilane were uniformly mixed. Next, this mixture is dispersed in an aqueous solution composed of 5 parts by weight of polyoxyethylene lauryl ether and 100 parts by weight of pure water, and further uniformly emulsified by a colloid mill, and then diluted by adding 200 parts by weight of pure water for condensation. An emulsion of a reactive crosslinkable silicone composition was prepared.

  Next, this emulsion was mixed with a condensation reaction catalyst prepared by dispersing 1 part by weight of tin (II) octylate in an aqueous solution consisting of 1 part by weight of polyoxyethylene lauryl ether and 9 parts by weight of pure water. After standing for 1 day, water was removed by a hot air dryer at 300 ° C. to prepare spherical silicone rubber powder (SR3) (average particle size: 2.0 μm).

Synthesis Example 3 (Preparation of spherical silicone rubber powder (SR4))
Average formula: 86.4 parts by weight of dimethylpolysiloxane represented by HO [(CH ₃ ) ₂ SiO] ₄₅ H, average formula: (CH ₃ ) ₃ SiO [(CH ₃ ) HSiO] ₄₀ Si (CH ₃ ) ₃ 9.1 parts by weight of methylhydrogenpolysiloxane blocked with a trimethylsiloxy group at both ends of a molecular chain and 4.5 parts by weight of 3-methacryloxypropyltrimethoxysilane were uniformly mixed. Next, this mixture is dispersed in an aqueous solution composed of 5 parts by weight of polyoxyethylene lauryl ether and 100 parts by weight of pure water, and further uniformly emulsified by a colloid mill, and then diluted by adding 200 parts by weight of pure water for condensation. An emulsion of a reactive crosslinkable silicone composition was prepared.

  Next, this emulsion was mixed with a condensation reaction catalyst prepared by dispersing 1 part by weight of tin (II) octylate in an aqueous solution consisting of 1 part by weight of polyoxyethylene lauryl ether and 9 parts by weight of pure water. After standing for 1 day, moisture was removed by a hot air dryer at 300 ° C. to prepare spherical silicone rubber powder (SR4) (average particle size: 1.5 μm).

Synthesis Example 4 (Preparation of spherical silicone rubber powder (SR5))
Average formula: HO (Si (CH ₃ ) (CH ₂ CH ₂ CF ₃ ) O) 75.5 parts by weight of methyl (3,3,3-trifluoropropyl) polysiloxane represented by _3.6 H, tetraethoxysilane partially 20.0 parts by weight of ethyl polysilicate represented by an average structural formula: (C ₂ H ₅ O) ₁₂ Si ₅ O ₄ and 4.5 parts by weight of 3-methacryloxypropyltrimethoxysilane formed by hydrolysis condensation reaction Were mixed uniformly. Next, this mixture is dispersed in an aqueous solution composed of 5 parts by weight of polyoxyethylene lauryl ether and 30 parts by weight of pure water, and further uniformly emulsified by a colloid mill, and then diluted by adding 158 parts by weight of pure water for condensation. An emulsion of a reactive crosslinkable silicone composition was prepared.

  Next, this emulsion was mixed with a condensation reaction catalyst prepared by dispersing 1 part by weight of tin (II) octylate in an aqueous solution consisting of 1 part by weight of polyoxyethylene lauryl ether and 9 parts by weight of pure water. After standing for 1 day, moisture was removed by a hot air dryer at 300 ° C. to prepare spherical fluorosilicone rubber particles (SR5) (average particle size: 3.7 μm).

Example 1
100 parts by weight of fluoro rubber, 43 parts by weight of silicone raw rubber SR1, 0.4 part by weight of TPPC, 5.7 parts by weight of TAIC and 2.1 parts by weight of Perhexa 25B were kneaded using two rolls. Subsequently, the obtained compound was press-crosslinked at 160 ° C. for 10 minutes under vacuum, and further oven-crosslinked at 180 ° C. for 4 hours to obtain a crosslinked molded product. Various rubber physical properties were tested using this crosslinked molded article. The test results are shown in Table 1.

Comparative Example 1
Except not using TPPC, kneading and crosslinking were carried out in the same manner as in Example 1 to obtain a crosslinked molded product. Various rubber physical properties were tested using this crosslinked molded article. The test results are shown in Table 1.

Example 2 to Example 5
100 parts by weight of fluoro rubber, 43 parts by weight of crosslinked silicone rubber fine particles SR2, 4.0 parts by weight of TAIC and 1.5 parts by weight of perhexa 25B are fixed, and phosphonium salts and basic fillers are as shown in Table 2. They were blended in proportions, kneaded and crosslinked in the same manner as described above, and various physical properties of the rubber were tested. The test results are shown in Table 2.

Comparative Example 2
Except not using TPPC, the mixture was kneaded and crosslinked in the same manner as in Example 2 to obtain a crosslinked molded product. Various rubber physical properties were tested using this crosslinked molded article. The test results are shown in Table 2.

Example 6 to Example 8
Fluoro rubber 100 parts by weight, TAIC 4.0 parts by weight, Perhexa 25B 1.5 parts by weight and BTPPC 0.4 parts by weight are fixed, and the crosslinked silicone rubber fine particles SR2 are blended in the proportions shown in Table 3, In the same manner as above, kneading and crosslinking were conducted, and various physical properties of rubber were tested. The test results are shown in Table 3.

Comparative Example 3
100 parts by weight of fluororubber, 0.4 parts by weight of BTPPC, 4.0 parts by weight of TAIC, and 1.5 parts by weight of perhexa 25B were kneaded and crosslinked in the same manner as described above to obtain a crosslinked molded product. Various rubber physical properties were tested using this crosslinked molded article. The test results are shown in Table 3.

Example 9
100 parts by weight of fluororubber, 43 parts by weight of crosslinked silicone rubber fine particles SR3, 0.4 parts by weight of TPPC, 4.0 parts by weight of TAIC and 1.5 parts by weight of perhexa 25B were kneaded and crosslinked in the same manner as described above to obtain various rubbers. Physical properties were tested. The test results are shown in Table 4.

Comparative Example 4
Except not using TPPC, the mixture was kneaded and crosslinked in the same manner as in Example 9 to obtain a crosslinked molded product. Various rubber physical properties were tested using this crosslinked molded article. The test results are shown in Table 4.

Examples 10 to 13
100 parts by weight of fluoro rubber, 43 parts by weight of crosslinked silicone rubber fine particles SR4, 4.0 parts by weight of TAIC and 1.5 parts by weight of perhexa 25B are fixed, and onium salts are blended in the proportions shown in Table 4. In the same manner as described above, kneading and crosslinking were conducted, and various physical properties of the rubber were tested. The test results are shown in Table 5.

Comparative Example 5
Except not using TPPC, the mixture was kneaded and crosslinked in the same manner as in Example 10 to obtain a crosslinked molded product. Various rubber physical properties were tested using this crosslinked molded article. The test results are shown in Table 5.

Example 14
100 parts by weight of fluororubber, 49 parts by weight of crosslinked silicone rubber fine particles SR5, 0.5 part by weight of BTPPC, 4.0 parts by weight of TAIC and 1.5 parts by weight of Perhexa 25B were kneaded and crosslinked in the same manner as described above, and various rubbers Physical properties were tested. The test results are shown in Table 6.

Comparative Example 6
Except not using BTPPC, it knead | mixed and bridge | crosslinked like Example 14, and the test of various rubber physical properties was done. The test results are shown in Table 6.

Claims (8)

A peroxide crosslinking composition comprising (A) a peroxide-crosslinkable fluororubber, (B) a silicone raw rubber or silicone rubber, and (C) an onium salt. The composition for peroxide crosslinking according to claim 1, wherein the component (B) is 5-200 parts by weight and the component (C) is 0.01-15 parts by weight with respect to 100 parts by weight of the component (A). The peroxide crosslinking composition according to claim 1 or 2, wherein the silicone rubber as the component (B) is a silicone rubber crosslinked particle obtained by crosslinking the silicone rubber composition. 4. The peroxide crosslinking composition according to claim 3, wherein the silicone rubber crosslinked particles of component (B) are particles having an aliphatic unsaturated bond-containing group on a silicon atom in the rubber. The composition for peroxide crosslinking according to any one of claims 1 to 4, wherein the component (B) has a fluorine-containing monovalent hydrocarbon group on a silicon atom in the rubber. (C) A component is a phosphonium salt, The composition for peroxide bridge | crosslinking in any one of Claims 1-5. A molded article obtained by subjecting the peroxide crosslinking composition according to any one of claims 1 to 6 to peroxide crosslinking. A fuel-permeable sealing material obtained by subjecting the peroxide crosslinking composition according to claim 1 to peroxide crosslinking.