Addition-curable self-adhesive silicone rubber composition and silicone rubber cured product

Abstract

The invention provides an addition-curable self-adhesive silicone rubber composition and a silicone rubber cured product. This addition-curable self-adhesive silicone rubber composition contains (A) an alkenyl group-containing organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule, (B-1) an organosilicon compound having 1-100 silicon atoms and having at least one phenylene skeleton in one molecule and at least one hydrogen atom bonded to silicon atoms, and (B-2) each containing a prescribed amount of (A) an alkenyl group-containing organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule, (B-1) an organosilicon compound having 1-100 silicon atoms and having at least one phenylene skeleton in one molecule, and (B-2) a prescribed amount of (B-2) a prescribed amount of (B-1) a prescribed amount of (B-2) a prescribed amount of (B-2) (C) a platinum-based catalyst; (D) a benzotriazole derivative; and (E) an acetylenic alcohol compound or a compound obtained by modifying an alcoholic hydroxyl group of the compound with a silane or a siloxane. The organohydrogenpolysiloxane contains at least two hydrogen atoms bonded to a silicon atom in one molecule and does not contain an aromatic group.

Description

[0001] This application is a divisional application of a Chinese patent application with the invention name “Addition-curing self-adhesive silicone rubber composition and silicone rubber cured product”, the application date of January 7, 2020, the priority date of January 11, 2019, and the application number of 202080008405.3. Technical Field

[0002] The present invention relates to an addition-curing self-adhesive silicone rubber composition and a silicone rubber cured product obtained by curing the composition. Background Art

[0003] Silicone rubber has good heat resistance, cold resistance, safety, electrical insulation, weather resistance, and durability, so it has been used in a wide range of fields such as automotive hoses, gasket materials, rollers for copiers, gaskets for microwave ovens, electrical and electronic parts, building components, and fiber coating materials. Among these various uses, there are many examples of using it as a component combined with metals, organic resins, etc.

[0004] So far, many methods have been proposed for obtaining articles in which a cured product of an addition-curing silicone rubber composition is integrated with a metal or an organic resin. Representative methods include a method of applying a primer to the surface of a molding resin, applying an uncured silicone rubber composition thereon, and curing the uncured silicone rubber composition to bond the two together; a method of applying an adhesive to the interface to integrate the two; a method of integrating the two by combining the two using two-color molding; and a method of curing a self-adhesive silicone rubber composition from the molding resin.

[0005] However, the method using adhesives and primers not only increases the number of steps, but also has problems such as dirtying the non-adhesive surface due to the coating method. In addition, in the method using two-color molding, there are problems such as the shape of the integrated product is restricted and the adhesion of the interface is insufficient. Therefore, in the case of using a self-adhesive silicone rubber composition in which an adhesive is added to the silicone rubber composition, since the above-mentioned coating process is not required, the operation time can be shortened, the cost can be reduced, and the workability is also improved, so it becomes an effective means in manufacturing an integrally molded body with a resin.

[0006] In the primer-free molding of addition-type heat-curing silicone rubber compositions, numerous methods of bonding with organic resins have been reported. For example, there is a method of curing a self-adhesive silicone rubber composition on a resin, and a large number of technologies for limiting the adhesive components of the self-adhesive silicone rubber composition have been proposed. In addition, there has been proposed a method of adding an organohydrogenpolysiloxane containing 30 mol % or more of hydrogen atoms directly bonded to silicon atoms to an organic resin to bond with an addition reaction-curing silicone rubber composition (Patent Document 1: Japanese Patent Publication No. 2-34311); a method of bonding and integrating a silicone rubber composition with an olefin resin grafted with a compound having an aliphatic unsaturated group and a hydrolyzable group bonded to a silicon atom (Patent Document 2: Japanese Patent Publication No. 63-183843); a method of bonding and integrating a thermoplastic resin to which a compound containing an aliphatic unsaturated group and a hydrogen atom directly bonded to a silicon atom has been added with a silicone rubber composition; and a method of adding a compound containing an aliphatic unsaturated group and a hydrogen atom directly bonded to a silicon atom to a thermoplastic resin. Integrally molded bodies of thermoplastic oligomer resins with aliphatic unsaturated groups and oil-dissolving silicone rubber (Patent Document 3: Japanese Patent Publication No. 9-165516, Patent Document 4: Japanese Patent Publication No. 9-165517); In a silicone rubber composition having self-adhesive properties and addition crosslinking properties, an organohydrogen polysiloxane having SiH bonds and aromatic skeletons in one molecule is added as an adhesion-enhancing material to a silicone rubber composition to bond with organic resins and metals (Patent Document 5: Japanese Patent Publication No. 6-172738, Patent Document 6: Japanese Patent Publication No. 2001-200162 and Patent Document 7: Japanese Patent Publication No. 2008-537967), etc. In order to use the above method to make it cure quickly at low temperature, it is necessary to increase the amount of catalyst or reduce the amount of control agent, but there are problems in the pot life. As a method for solving this problem, the following method has been proposed: by adding a trace amount of triazole compounds to a self-adhesive addition-crosslinking silicone rubber composition, it is possible to cope with the situation where the softening point of the organic resin is low, to cure quickly at low temperatures, and to obtain a pot life sufficient for workability (Patent Document 8: Japanese Patent Gazette No. 2014-122271), etc.

[0007] In addition, when the above-mentioned addition-curing self-adhesive silicone rubber is used as a gasket such as an O-ring or a gasket, a low compression set is required to prevent seal leakage. Usually, in order to reduce the compression set, the rubber formed by heat curing must be further subjected to secondary vulcanization at high temperature for a long time. However, in the case of a self-adhesive silicone rubber including an organic resin, there are problems such as low heat resistance of the organic resin, deformation of the resin, and degradation. On the other hand, a method of adding a triazole compound to an addition-curing silicone rubber composition to reduce the compression set without secondary vulcanization has been proposed (Patent Document 9: Japanese Patent Publication No. 2-242854). However, in this case, the curing speed is reduced, and in particular, in the case of molding at low temperatures (below 120°C), there is a problem of excessively prolonged molding time. In addition, when a trace amount of a triazole compound is used to the extent that the curability is not impaired as in Patent Document 8, the compression set cannot be improved.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Publication No. 2-34311

[0011] Patent Document 2: Japanese Patent Application Laid-Open No. 63-183843

[0012] Patent Document 3: Japanese Patent Application Laid-Open No. 9-165516

[0013] Patent Document 4: Japanese Patent Application Laid-Open No. 9-165517

[0014] Patent Document 5: Japanese Patent Application Laid-Open No. 6-172738

[0015] Patent Document 6: Japanese Patent Application Publication No. 2001-200162

[0016] Patent Document 7: Japanese Patent Application No. 2008-537967

[0017] Patent Document 8: Japanese Patent Application Publication No. 2014-122271

[0018] Patent Document 9: Japanese Patent Application Laid-Open No. 2-242854 Summary of the invention

[0019] Problems to be solved by the invention

[0020] The present invention has been made in view of the above-mentioned actual situation, and an object of the present invention is to provide an addition-curing self-adhesive silicone rubber composition and a silicone rubber cured product which can be molded at a relatively low temperature and in a short time when obtaining an integrally molded body of a silicone rubber composition and a thermoplastic resin used in automobile parts, communication equipment, and other various electrical and electronic products, and which has a sufficient pot life for operation and can form a cured product with low compression set.

[0021] Means for solving problems

[0022] The present inventors have conducted in-depth studies to achieve the above-mentioned purpose and have found that in an addition-curing self-adhesive silicone rubber composition containing the following components:

[0023] (A) an alkenyl group-containing organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule,

[0024] (B-1) an organic silicon compound having 1 to 100 silicon atoms and having at least one phenylene skeleton and at least one hydrogen atom bonded to the silicon atom in one molecule,

[0025] (B-2) an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to silicon atoms in one molecule and containing no aromatic group,

[0026] (C) Platinum catalysts,

[0027] (E) an acetylene alcohol compound or a compound in which the alcoholic hydroxyl group of the compound is modified with silane or siloxane,

[0028] The present invention has been completed by using a composition in which the ratio of the molar number of hydrogen atoms bonded to silicon atoms of the components (B-1) and (B-2) to the total molar number of hydrogen atoms bonded to silicon atoms of the components (B-1) and (B-2) is limited, and an effective amount of a benzotriazole derivative (D) is added to 1 mole of platinum atoms of the component (C). This allows molding at a relatively low temperature and in a short time, while having a pot life sufficient for operation and obtaining a cured product with low compression set.

[0029] Therefore, the present invention provides the following addition-curing self-adhesive silicone rubber composition and silicone rubber cured product.

[0030] [1] An addition-curing self-adhesive silicone rubber composition comprising:

[0031] (A) 100 parts by mass of an alkenyl group-containing organopolysiloxane having at least two alkenyl groups bonded to a silicon atom in one molecule,

[0032] (B-1) 0.05 to 10 parts by mass of an organic silicon compound having at least one phenylene skeleton and at least one hydrogen atom bonded to the silicon atom and having 1 to 100 silicon atoms in one molecule,

[0033] (B-2) an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to silicon atoms in one molecule and containing no aromatic groups: 0.2 to 30 parts by mass, in an amount such that the number of moles of Si-H groups in each of the components (B-1) and (B-2) relative to the total number of moles of hydrogen atoms (Si-H groups) bonded to silicon atoms in the components (B-1) and (B-2) (total Si-H groups) is [Si-H groups (B-1)] / [total Si-H groups]=1 to 50 mol%, [Si-H groups (B-2)] / [total Si-H groups]=50 to 99 mol%,

[0034] (C) platinum-based catalyst: 0.5 to 500 ppm in terms of platinum metal (by mass) relative to the total mass of components (A), (B-1) and (B-2),

[0035] (D) a benzotriazole derivative represented by the following general formula (I): 2 to 100 mol per 1 mol of platinum atoms of the component (C);

[0036] [Chemistry 1]

[0037]

[0038] [Where R 1 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, R 2 It is a monovalent hydrocarbon group having 1 to 15 carbon atoms or a group represented by the following formula (I').

[0039] [Chemistry 2]

[0040]

[0041] (Where R 3 -(CH2) a -Si(OR 4 )3, R 4 is an alkyl group with 1 to 4 carbon atoms or SiR 5 3-base (R 5 is an alkyl group having 1 to 4 carbon atoms), and a is an integer of 1 to 6. * represents a bonding point. )]

[0042] (E) An acetylene alcohol compound or a compound obtained by modifying the alcoholic hydroxyl group of the compound with silane or siloxane: 1 to 500 mol of acetylene per 1 mol of platinum atoms of the component (C).

[0043] [2] The addition-curing self-adhesive silicone rubber composition described in [1], wherein the molar ratio of the total Si-H groups to the total alkenyl groups in the silicone rubber composition (total alkenyl groups) is [total Si-H groups] / [total alkenyl groups]=2.0 to 3.0.

[0044] [3] The addition-curing self-adhesive silicone rubber composition according to [1] or [2], further comprising 5 to 100 parts by mass of reinforcing silica fine powder as the component (F) based on 100 parts by mass of the component (A).

[0045] [4] The addition-curing self-adhesive silicone rubber composition of [3], wherein the component (F) has a specific surface area of ​​50 m2 according to the BET method. 2 / g or more of fumed silica.

[0046] [5] An addition-curing self-adhesive silicone rubber composition, wherein the silicone rubber composition described in any one of [1] to [4] is uniformly mixed, and the shear rate is 0.9 s after standing at 25° C. for 10 minutes and after standing at 24 hours. -1 The viscosities under 24 When η 24 / η0≤2.

[0047] [6] A silicone rubber cured product obtained by curing the silicone rubber composition according to any one of [1] to [5], wherein the product has a compression rate of 25% and a compression set of 30% or less after compression at 150°C for 22 hours based on JIS K 6249:2003.

[0048] The present invention also provides the following addition-curing self-adhesive silicone rubber composition and silicone rubber cured product.

[0049] [1']. An addition-curing self-adhesive silicone rubber composition comprising:

[0050] (A) 100 parts by mass of an alkenyl group-containing organopolysiloxane having at least two alkenyl groups bonded to a silicon atom in one molecule,

[0051] (B-1) 0.05 to 10 parts by mass of an organic silicon compound having at least one phenylene skeleton and at least one hydrogen atom bonded to the silicon atom and having 1 to 100 silicon atoms in one molecule,

[0052] (B-2) an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to silicon atoms in one molecule and containing no aromatic groups: 0.2 to 30 parts by mass, in an amount such that the number of moles of Si-H groups in each of the components (B-1) and (B-2) relative to the total number of moles of hydrogen atoms (Si-H groups) bonded to silicon atoms in the components (B-1) and (B-2) (total Si-H groups) is [Si-H groups (B-1)] / [total Si-H groups]=1 to 25 mol%, [Si-H groups (B-2)] / [total Si-H groups]=75 to 99 mol%,

[0053] (C) platinum-based catalyst: 0.5 to 500 ppm in terms of platinum metal mass relative to the total mass of components (A), (B-1) and (B-2),

[0054] (D) a benzotriazole derivative represented by the following general formula (I): 2 to 100 mol per 1 mol of platinum atoms of the component (C);

[0055] [Chemical 1']

[0056]

[0057] In the formula, R 1 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, R 2 is a monovalent hydrocarbon group having 1 to 15 carbon atoms or a group represented by the following formula (I'),

[0058] [Chemistry 2']

[0059]

[0060] In the formula, R 3 -(CH2) a -Si(OR 4 )3, R 4 is an alkyl group with 1 to 4 carbon atoms or SiR 5 3 base, R 5 is an alkyl group having 1 to 4 carbon atoms, a is an integer of 1 to 6, and * represents a bonding point.

[0061] (E) An acetylene alcohol compound or a compound obtained by modifying the alcoholic hydroxyl group of the compound with silane or siloxane: 1 to 500 mol of acetylene per 1 mol of platinum atoms of the component (C).

[0062] [2']. The addition-curing self-adhesive silicone rubber composition according to [1'], wherein the molar ratio of the total Si-H groups to the total alkenyl groups in the silicone rubber composition, i.e., the total alkenyl groups, is [total Si-H groups] / [total alkenyl groups]=2.0 to 3.0.

[0063] [3']. The addition-curing self-adhesive silicone rubber composition according to [1'], further comprising 5 to 100 parts by mass of reinforcing silica fine powder as component (F), relative to 100 parts by mass of component (A).

[0064] [4']. The addition-curing self-adhesive silicone rubber composition according to [3'], wherein the component (F) has a specific surface area of ​​50 m according to the BET method. 2 / g or more of fumed silica.

[0065] [5']. An addition-curing self-adhesive silicone rubber composition, wherein the silicone rubber composition according to [1'] is uniformly mixed, and the shear rate is 0.9 s after standing at 25°C for 10 minutes and after standing for 24 hours. -1 The viscosities under 24 When η 24 / η0≤2.

[0066] [6'] A silicone rubber cured product obtained by curing the silicone rubber composition described in any one of [1'] to [5'], wherein the compression set after compression at a compression rate of 25% and 150°C for 22 hours is 30% or less.

[0067] Effects of the Invention

[0068] According to the present invention, an addition-curing self-adhesive silicone rubber composition can be provided which can form a silicone rubber having low compression set and excellent adhesion to various organic resins without sacrificing curing speed, and a silicone rubber cured product obtained by curing the composition. DETAILED DESCRIPTION

[0069] The present invention is described in more detail below.

[0070] [Addition-curing self-adhesive silicone rubber composition]

[0071] The addition-curing self-adhesive silicone rubber composition of the present invention contains the following components (A), (B-1), (B-2), (C), (D), and (E).

[0072] (A) Alkenyl-containing organopolysiloxane

[0073] The organopolysiloxane containing at least two alkenyl groups bonded to silicon atoms in one molecule as the component (A) is the main agent (base polymer) of the present composition. As the component (A), a compound represented by the following average composition formula (II) can be used.

[0074] R 6 b SiO (4-b) / 2 (II)

[0075] (Where R 6 are identical or different unsubstituted or substituted monovalent hydrocarbon groups having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and b is a positive number in the range of 1.5 to 2.8, preferably 1.8 to 2.5, more preferably 1.95 to 2.05.

[0076] Among them, as R 6 The unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms represented by the radical may include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, nonyl, and decyl, aryl groups such as phenyl, tolyl, xylyl, and naphthyl, aralkyl groups such as benzyl, phenylethyl, and phenylpropyl, and alkenyl groups such as vinyl, allyl, propenyl, isopropenyl, butenyl, hexenyl, cyclohexenyl, and octenyl. Groups in which a part or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine, bromine, and chlorine, or cyano groups, such as chloromethyl, chloropropyl, bromoethyl, trifluoropropyl, and cyanoethyl, are preferred. All R 6 90 mol% or more, especially all R except alkenyl 6 It is methyl.

[0077] In addition, R 6 At least two of them must be alkenyl groups (preferably alkenyl groups having 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms, and particularly preferably vinyl groups).

[0078] In addition, the content of alkenyl groups in the organopolysiloxane is preferably 1.0×10 -6 ~5.0×10 -3 mol / g, particularly preferably 1.0×10 -5 ~2.0×10 -3 mol / g. If the content is 1.0×10 -6 ~5.0×10 -3 The alkenyl group may be bonded to a silicon atom at the end of the molecular chain, to a silicon atom in the middle of the molecular chain, or to both.

[0079] The structure of the organopolysiloxane has a substantially linear structure in which both ends of the molecular chain are capped with triorganosiloxy groups and the main chain is composed of repeated diorganosiloxane units, and may partially have a branched structure, a cyclic structure, or the like.

[0080] Regarding the molecular weight, the average degree of polymerization (number average degree of polymerization, the same below) is 1500 or less, usually 100 to 1500, preferably 150 to 1000. If the average degree of polymerization is 100 to 1500, a rubber-like substance is obtained, and moldability becomes good. The average degree of polymerization is usually obtained by using toluene as an elution solvent and can be obtained as a polystyrene conversion value in GPC (gel permeation chromatography) analysis.

[0081] As the component (A), as long as it is an organopolysiloxane containing alkenyl groups bonded to silicon atoms at both ends of the molecular chain, one or more organopolysiloxanes having different molecular structures and polymerization degrees may be used in combination.

[0082] (B-1) an organic silicon compound having a phenylene skeleton and a hydrogen atom bonded to a silicon atom

[0083] The component (B-1) functions as an adhesiveness-imparting component (adhesive aid) and a crosslinking agent, and is an organosilicon compound such as an organosilane or organopolysiloxane having at least one SiH group (hydrogen atom bonded to a silicon atom) in one molecule and at least one phenylene skeleton, and generally having 1 to 100, preferably about 2 to 30 silicon atoms in one molecule. It should be noted that the "phenylene skeleton" in the present invention includes a polyvalent aromatic ring structure such as a divalent to hexavalent, particularly a divalent to tetravalent, benzene structure, naphthalene structure, anthracene structure, etc.

[0084] As the above-mentioned compound, it is preferred to use an organosilicon compound such as a linear or cyclic organosiloxane oligomer, an organoalkoxysilane, etc., which has at least one SiH group (i.e., hydrogen atoms bonded to a silicon atom) in one molecule, usually 1 to 20, and particularly about 2 to 10, and has at least one, usually 1 to 4 phenylene skeletons, and may contain one or more epoxy groups such as a glycidyloxy group, an alkoxysilyl group such as a trimethoxysilyl group, a triethoxysilyl group, and a methyldimethoxysilyl group, an ester group, an acryloyl group, a methacryloyl group, a carboxylic anhydride group, an isocyanate group, an amino group, an acylamino group, etc., and has 1 to 30 silicon atoms, preferably 2 to 20, and particularly preferably about 4 to 10.

[0085] Specific examples of such a compound include the following compounds.

[0086] [Chemistry 3]

[0087]

[0088] (In the formula, n = 1 to 4.)

[0089] [Chemistry 4]

[0090]

[0091] [wherein, X is the following

[0092] [Chemistry 5]

[0093]

[0094] Y is selected from the following

[0095] [Chemistry 6]

[0096]

[0097] (wherein, R' is selected from the following

[0098] [Chemistry 7]

[0099]

[0100] The group in R w , R x is an unsubstituted or substituted monovalent hydrocarbon group. n=1 to 4, q=1 to 50, h=0 to 100, preferably q=1 to 20, h=1 to 50. ) in which R" is selected from the following

[0101] [Chemistry 8]

[0102]

[0103] (Where R w , R x Same as above, y = 0 to 100.)

[0104] The group in which Y' is selected from the following

[0105] [Chemistry 9]

[0106]

[0107] (Where R w , R x , n, q, h are the same as above. )

[0108] The group in. z=1~10. ]

[0109] Furthermore, organic compounds and organosilicon compounds containing alkoxysilyl groups such as trimethoxysilyl, triethoxysilyl and methyldimethoxysilyl, acryloyl, methacryloyl, ester, carboxylic anhydride, isocyanate, amino and acylamino groups can also be used among the above compounds.

[0110] Furthermore, as the above R w , R xunsubstituted or substituted monovalent hydrocarbon group, preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms, particularly 1 to 8 carbon atoms, including alkyl, aryl, aralkyl, alkenyl, etc. 6 In addition to the same groups as those exemplified in , examples of the substituted monovalent hydrocarbon group include groups substituted with an alkoxy group, an acrylate group, a methacrylate group, an acryloyl group, a methacryloyl group, an amino group, an alkylamino group, and the like.

[0111] The amount of component (B-1) is 0.05 to 10 parts by mass, preferably 0.1 to 9 parts by mass, and more preferably 0.2 to 8 parts by mass, relative to 100 parts by mass of component (A). When the amount is 0.05 to 10 parts by mass, the adhesiveness becomes good. The organosilicon compound having a phenylene skeleton of component (B-1) may be used alone or in combination of two or more.

[0112] (B-2) Organohydrogenpolysiloxane

[0113] The organohydrogenpolysiloxane of the component (B-2) is an organohydrogenpolysiloxane having at least 2, preferably 3 or more hydrogen atoms bonded to silicon atoms (i.e., SiH groups) in one molecule and having no aromatic groups such as phenyl or phenylene skeletons in the molecule, and is not equivalent to the organohydrogenpolysiloxane of the component (B-1). The organohydrogenpolysiloxane of the component (B-2) is represented by the following average composition formula (III), and it is preferred to use an organohydrogenpolysiloxane having at least 2 (usually 2 to 200), preferably 3 or more (usually 3 to 200), more preferably 5 to 100, and even more preferably about 8 to 50 hydrogen atoms (SiH groups) bonded to silicon atoms in one molecule.

[0114] R 7 c H d SiO (4-c-d) / 2 (III)

[0115] (Where R 7 It is an unsubstituted or substituted aliphatic monovalent hydrocarbon group having 1 to 10 carbon atoms. In addition, c is 0.7 to 2.1, d is 0.001 to 1.0, and c+d is a positive number satisfying 0.8 to 3.0. )

[0116] In the above formula, R 7 The unsubstituted or substituted aliphatic monovalent hydrocarbon group having 1 to 10 carbon atoms may be exemplified by the group consisting of R 6 The same groups as those exemplified do not contain aryl groups such as phenyl groups and aromatic groups such as aralkyl groups, and are preferably hydrocarbons (aliphatic saturated hydrocarbons) not containing aliphatic unsaturated bonds such as alkenyl groups, and specifically, are preferably alkyl groups, particularly preferably methyl groups.

[0117] Furthermore, c is 0.7 to 2.1, preferably 0.8 to 2.0, d is 0.001 to 1.0, preferably 0.01 to 1.0, and c+d is 0.8 to 3.0, preferably a positive number satisfying 1.0 to 2.5.

[0118] The molecular structure of the organohydrogenpolysiloxane of the component (B-2) may be a linear, cyclic, branched, or three-dimensional network structure. In this case, the number of silicon atoms (or degree of polymerization) in one molecule is usually 2 to 300, preferably 3 to 200, more preferably 10 to 200, and further preferably 15 to 100. It is preferred to use an organohydrogenpolysiloxane that is liquid at room temperature (25°C).

[0119] The hydrogen atom bonded to the silicon atom may be located at either the end of the molecular chain or in the middle of the molecular chain (not at the end of the molecular chain), or may be located at both ends.

[0120] Examples of the organohydrogen polysiloxane of the component (B-2) include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, methylhydrogen cyclopolysiloxane, methylhydrogen cyclosiloxane-dimethylsiloxane cyclic copolymer, tris(dimethylhydrogen siloxy)methylsilane, methylhydrogen polysiloxane terminated at both ends with trimethylsiloxy, dimethylhydrogen siloxane-methylhydrogen siloxane copolymer terminated at both ends with trimethylsiloxy, dimethylhydrogen polysiloxane-methylhydrogen siloxane copolymer terminated at both ends with dimethylhydrogen siloxy, dimethylhydrogen siloxane-methylhydrogen siloxane copolymer terminated at both ends with dimethylhydrogen siloxy, (CH3)2HSiO 1 / 2 Unit and SiO 4 / 2 The copolymer is composed of (CH3)3SiO 1 / 2 Unit and (CH3)2HSiO 1 / 2 Unit and SiO 4 / 2 The copolymer consists of (CH3)2HSiO 1 / 2 Unit and SiO 4 / 2 Unit and (CH3)SiO 3 / 2 The copolymer consists of (CH3)2HSiO 1 / 2 Unit and SiO 4 / 2 Unit and (CH3)2SiO 2 / 2 Copolymers composed of units, etc.

[0121] The content of hydrogen atoms (SiH groups) bonded to silicon atoms in the organohydrogenpolysiloxane as the component (B-2) is preferably 0.0005 to 0.017 mol / g, more preferably 0.0008 to 0.017 mol / g. When the content is 0.0005 to 0.017 mol / g, crosslinking becomes sufficient and a stable material can be obtained.

[0122] The amount of the organohydrogenpolysiloxane of the component (B-2) is preferably 0.2 to 30 parts by mass, more preferably 0.2 to 20 parts by mass, and particularly preferably 0.3 to 15 parts by mass relative to 100 parts by mass of the component (A). When the amount is 0.2 to 30 parts by mass, the curing property is good and the compression set is also good. The organohydrogenpolysiloxane of the component (B-2) may be used alone or in combination of two or more.

[0123] Regarding the mixing ratio of the components (B-1) and (B-2), the molar number of Si-H groups of each component relative to the total molar number of hydrogen atoms (Si-H groups) bonded to silicon atoms (total Si-H groups) is: [Si-H groups (B-1)] / [total Si-H groups] is 1 to 50 mol%, preferably 1 to 30 mol%, and more preferably 1 to 25 mol%. In addition, [Si-H groups (B-2)] / [total Si-H groups] is 50 to 99 mol%, preferably 70 to 99 mol%, and more preferably 75 to 99 mol%. Regarding the mixing ratio of the components (B-1) and (B-2), if the component (B-1) exceeds 50 mol%, the curability deteriorates and the compression set increases, which is not preferred. If the component (B-1) is less than 1 mol%, there is a possibility that adhesion will not be shown, which is not preferred.

[0124] The total amount of the components (B-1) and (B-2) is such that the molar ratio (total Si-H groups / total alkenyl groups) of the total Si-H groups in the organohydrogenpolysiloxane of the components (B-1) and (B-2) and the total amount of alkenyl groups in the composition (i.e., the total amount of alkenyl groups in the components (A) and (E) when a substance having alkenyl groups is added to the component (E) described later in addition to the alkenyl groups in the component (A) described above) is 2.0 to 3.0, more preferably 2.0 to 2.8. When the molar ratio is 2.0 to 3.0, the curing property is good and the compression set is good.

[0125] (C) Platinum catalyst

[0126] (C) Components include platinum-based catalysts such as platinum black, platinum chloride, chloroplatinic acid, a reaction product of chloroplatinic acid and a monohydric alcohol, a complex of chloroplatinic acid and olefins, and bisacetoacetate platinum.

[0127] The amount of the platinum catalyst can be set to a catalytic amount, and is usually set to 0.5 to 500 ppm, particularly about 1 to 200 ppm, relative to the total mass of the components (A), (B-1) and (B-2) in terms of platinum metal (by mass). The platinum catalyst of the component (C) can be used alone or in combination of two or more.

[0128] (D) Benzotriazole derivatives

[0129] Component (D) is represented by the following general formula (I):

[0130] [Chemistry 10]

[0131]

[0132] [Where R 1 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, R 2 It is a monovalent hydrocarbon group having 1 to 15 carbon atoms or a group represented by the following formula (I').

[0133] [Chemistry 11]

[0134]

[0135] (Where R 3 -(CH2) a -Si(OR 4 )3, R 4 1 to 4 alkyl or SiR 5 3-base (R 5 is an alkyl group with 1 to 4 radicals), and a is an integer with 1 to 6 radicals. * represents a bonding point. )]

[0136] The benzotriazole derivative represented by the present invention can reduce the compression set of the silicone rubber after curing by interacting with the platinum-based catalyst of the above-mentioned component (C), thereby obtaining a pot life sufficient for the work.

[0137] Among them, R 1 It is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 6 carbon atoms include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, and cyclohexyl, and groups in which a part or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine, bromine, and chlorine, or cyano groups, such as chloromethyl, chloropropyl, bromoethyl, trifluoropropyl, and cyanoethyl. Among these, a hydrogen atom or a methyl group is preferred from the viewpoint of synthesis.

[0138] Specific examples of the benzotriazole derivatives are shown below.

[0139] [Chemistry 12]

[0140]

[0141] (wherein, l is an integer from 1 to 6, R 4 is an alkyl or trialkylsilyl group. )

[0142] Among these, the most preferred examples are shown by the following formula.

[0143] [Chemistry 13]

[0144]

[0145] [Chemistry 14]

[0146]

[0147] The amount of component (D) is 2 to 100 mol, preferably 5 to 75 mol, and more preferably 10 to 50 mol, relative to 1 mol of platinum atom of component (C). If the amount is 2 to 100 mol, the curability and compression set become good, and a sufficient pot life for the operation is obtained. The benzotriazole derivative of component (D) may be used alone or in combination of two or more.

[0148] (E) an acetylene alcohol compound or a compound modified with silane or siloxane

[0149] The component (E) is an acetylene alcohol compound or a compound in which the alcoholic hydroxyl group of the compound is modified with silane or siloxane. The component (E) functions as a reaction controller for the platinum catalyst of the component (C), and the curing start time can be controlled by the amount added.

[0150] The acetylene alcohol compound of the component (E) may be any compound as long as the acetylene group and the hydroxyl group are present in the same molecule, and preferably the acetylene group and the hydroxyl group are bonded to the same carbon atom. Specific examples include the following compounds.

[0151] [Chemistry 15]

[0152]

[0153] In addition, the alcoholic hydroxyl group of the acetylene alcohol compound is modified with silane or siloxane in such a way that the hydroxyl group of the acetylene alcohol is converted into a Si—OC bond and is bonded to silane or siloxane.

[0154] [Chemistry 16]

[0155]

[0156] (wherein, s is an integer of 0 to 50, preferably an integer of 3 to 20, and t is an integer of 1 to 50, preferably an integer of 3 to 20.)

[0157] The amount of the component (E) is 1 to 500 mol / mol, preferably 1 to 300 mol / mol, and more preferably 2 to 200 mol / mol, relative to the platinum catalyst of the component (C). If the amount is 1 to 500 mol / mol, the curing property is good and a sufficient pot life for the operation can be obtained. The component (E) can be used alone or in combination of two or more.

[0158] (F) Reinforcing silica powder

[0159] The silicone rubber composition of the present invention is preferably formulated with reinforcing silica fine powder as the (F) component. As for the reinforcing silica fine powder of the (F) component, there is no particular limitation on the type of silica, and silica generally used as a reinforcing agent for rubber may be used. As the reinforcing silica fine powder, the reinforcing silica fine powder used in the existing silicone rubber composition can be used, and the specific surface area obtained by the BET method is 50 m 2 It is preferred to use a reinforcing silica fine powder having a specific surface area of ​​50 to 400 m2 obtained by the BET method. 2 / g, especially 100~350m 2 / g, precipitated silica (wet silica), fumed silica (dry silica), pyrogenic silica (pyrogenic silica), etc., from the perspective of improving rubber strength, preferably fumed silica. In addition, the above-mentioned reinforcing silica fine powder can be a silica fine powder that has been hydrophobized on the surface with a surface treatment agent described later. In this case, these silica fine powders can be the product of directly carrying out surface hydrophobization treatment using a surface treatment agent in advance under the state of powder, or can be a surface treatment agent added during mixing with silicone oil (such as the organopolysiloxane containing alkenyl of the above-mentioned (A) component), and the product of surface hydrophobization treatment has been carried out.

[0160] As a surface treatment method, it is possible to use known techniques for surface treatment, for example, in a closed mechanical mixing device or fluidized bed at normal pressure, the above-mentioned untreated silica powder and a surface treatment agent are placed, and mixed treatment is carried out at room temperature or heat treatment (under heating) in the presence of an inert gas as required. A catalyst (hydrolysis promoter, etc.) can be used to promote surface treatment according to the situation. After mixing, by drying, surface-treated silica powder can be manufactured. The amount of the surface treatment agent can be more than the amount calculated by the coating area of ​​the treatment agent.

[0161] As surface treatment agent, specifically, silazanes such as hexamethyldisilazane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, trimethylmethoxysilane, triethylmethoxysilane, vinyltri(methoxyethoxy)silane, trimethylchlorosilane, dimethyldichlorosilane, divinyldimethoxysilane and chloropropyltrimethoxysilane and other silane coupling agents, polymethylsiloxane, organohydrogenpolysiloxane and other organosilicon compounds can be listed, surface treatment is carried out with these, as hydrophobic silica fine powder use.As surface treatment agent, particularly preferred silane coupling agent or silazanes.(F) The fine powder silica of component can be used alone 1 kind, also can be used with 2 or more kinds.

[0162] In the addition-curing self-adhesive silicone rubber composition of the present invention, in addition to the above-mentioned components, various additives can be added as needed, such as metal oxides such as titanium oxide, iron oxide, cerium oxide, vanadium oxide, cobalt oxide, chromium oxide, manganese oxide, and their composites, quartz powder, diatomaceous earth, calcium carbonate, magnesium carbonate, aluminum oxide, carbon, hollow glass, hollow resin, gold, silver, copper, and other conductive inorganic powders, plating powders, and other inorganic fillers, and pigments, heat-resistant agents, flame retardants, plasticizers, etc. can be added as long as the target properties are not impaired. In addition, the addition amount of these optional components can be set to a normal amount within the range that does not hinder the effect of the present invention.

[0163] [Method for preparing addition-curing self-adhesive silicone rubber composition]

[0164] The addition-curing self-adhesive silicone rubber composition of the present invention can be obtained simply by uniformly mixing the above-mentioned components (A) to (E) and optional components at room temperature. Preferably, the component (F) can be heat-treated together with the surface treatment agent and water with the entire amount or a part of the component (A) at a temperature of 100 to 200° C. for 1 to 4 hours using a planetary mixer, kneader, etc., and after cooling to room temperature, the remaining components and optional components are added and mixed to obtain the composition.

[0165] As for the viscosity of the composition of the present invention, the shear rate at 25°C is 0.9s -1 The viscosity at 50 to 5000 Pa·s is preferably 80 to 4000 Pa·s, and even more preferably 100 to 3000 Pa·s. When the viscosity is less than 50 Pa·s or exceeds 5000 Pa·s, molding may become difficult.

[0166] In addition, in the present invention, the viscosity can be measured using a shear viscometer: HAAKE MARS40 Rheometer (manufactured by Thermo Fisher Scientific).

[0167] In the composition of the present invention, the above-mentioned components (A) to (E) and the optional components are uniformly mixed, and the shear rate is 0.9 s after standing at 25°C for 10 minutes and after standing for 24 hours. -1 The viscosities under 24 When, preferably η 24 / η0≤2, more preferably 1≤η 24 / η0≤2, more preferably 1≤η 24 / η0≤1.8. 24 In the case of / η0>2, the pot life after uniform mixing may be short and workability may be reduced.

[0168] As for the curing speed of such addition-curing self-adhesive silicone rubber composition, if the efficiency is emphasized, the 10% and 90% curing times (i.e., the time from the start of measurement to the time when the torque value of 10% and 90% of the maximum torque value at 110°C at 3 minutes from the start of measurement) measured at 110°C for 3 minutes using a curing tester [rotorless disc rheometer, dynamic mode rheometer, or MDR2000 (manufactured by Alpha Technology)] are preferably 10 seconds ≤ T10 ≤ 60 seconds, T10 ≤ T90 ≤ T10 + 50 seconds, and more preferably 15 seconds ≤ T10 ≤ 50 seconds, T10 ≤ T90 ≤ T10 + 40 seconds. If the curing speed is 10 seconds ≤ T10 ≤ 60 seconds, T10 ≤ T90 ≤ T10 + 50 seconds, the molding cycle becomes good.

[0169] [Molding method of addition-curing self-adhesive silicone rubber composition / cured silicone rubber]

[0170] The molding method of the addition-curing self-adhesive silicone rubber composition can be freely selected according to the viscosity of the mixture, and any method such as casting molding, compression molding, dispenser molding, injection molding, extrusion molding, transfer molding, etc. can be adopted.

[0171] In particular, in order to effectively utilize the adhesiveness of the composition of the present invention, it is preferred to preliminarily place the adherend (organic resin) in a mold, bring the uncured composition into contact with it and cure it to obtain a molded product integrating the two (insert molding), or to perform two-color molding by alternately injecting molten or uncured organic resin and the composition into the mold to obtain an integrated product.

[0172] The composition of the present invention can be well bonded to organic resins. As the organic resin used as the above-mentioned adherend, conventional olefin polymerization or polycondensation thermoplastic resins can be listed, and specifically, acrylonitrile-butadiene-styrene (ABS) resin, polycarbonate (PC) resin, polyurethane (PU) resin, styrene resin, polyethylene (PE) resin, polypropylene (PP) resin, acrylic (ester) resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polyphenylene ether (PPO) resin, polyphenylene sulfide (PPS) resin, polysulfone resin, nylon (PA) resin, aromatic polyamide (aromatic PA) resin, polyimide (PI) resin, liquid crystal resin, etc. can be listed.

[0173] As for the curing conditions, it is generally possible to heat mold at 60 to 220°C for 5 seconds to 1 hour. In order to show strong adhesion with thermoplastic resins, it is preferred to cure at a temperature where the resin does not deform, melt, or deteriorate. It also depends on the type of resin, the thickness of the rubber, etc., but in the case of a resin with a high softening point, it can be cured at 120 to 220°C for 5 seconds to 5 minutes, and in the case of a resin with a low softening point, it can be cured at 60 to 120°C for 15 seconds to 30 minutes to obtain an integral molded body.

[0174] The cured product (cured silicone rubber product) obtained by curing the addition-curing self-adhesive silicone rubber composition preferably has a compression set of 30% or less in a compression set measurement based on JIS K 6249:2003 at a compression rate of 25%, 150°C, and 22 hours. In particular, if the compression set is 30% or less, it is preferably used as a material for O-rings and gaskets. In order to achieve such compression set, it can be achieved by using a product in which the component (D) is uniformly mixed in the above-mentioned mixing ratio in the addition-curing self-adhesive silicone rubber composition containing the components (A) to (C) and (E).

[0175] As described above, the silicone rubber cured product thus obtained can be molded at a relatively low temperature and in a short time when an integrally molded body with a silicone rubber composition and a thermoplastic resin used in automobile parts, communication equipment, and other various electrical and electronic products is obtained, and at the same time has a sufficient pot life for operation, and can be a cured product with low compression set.

[0176] Example

[0177] The present invention is specifically described below by way of examples and comparative examples, but the present invention is not limited to the following examples. It should be noted that in the following examples, parts represent parts by mass. In addition, the average degree of polymerization represents the number average degree of polymerization.

[0178] [Preparation Example 1]

[0179] 60 parts of dimethylpolysiloxane (A1) having an average polymerization degree of 750 and a specific surface area of ​​300 m2 obtained by the BET method, wherein both ends of the molecular chain are blocked with dimethylvinylsiloxy groups, 2 40 parts of fumed silica (F1) (AEROSIL 300 manufactured by AEROSIL Co., Ltd., Japan) with a weight of 100 g / g, 8.0 parts of hexamethyldisilazane and 2.0 parts of water were mixed at room temperature for 60 minutes, heated to 150°C and stirred for 4 hours. Then, 30 parts of dimethylpolysiloxane (A1) were added, mixed until uniform, and cooled to obtain silicone rubber base material A.

[0180] [Example 1]

[0181] To 100 parts of silicone rubber base material A, 5.70 parts of dimethylpolysiloxane (A2) having an average polymerization degree of 220 and having both ends of the molecular chain blocked with dimethylvinylsiloxy groups, 5.03 parts of dimethylpolysiloxane (A3) having an average polymerization degree of 200 and having both ends of the molecular chain blocked with trimethylsiloxy groups and 5 mol% of the methyl groups in the side chains (i.e., monovalent groups or atoms bonded to silicon atoms in the diorganosiloxane units constituting the main chain, the same below) being vinyl groups, and an adhesive agent (B-1) having a phenylene skeleton represented by the following formula (1) (SiH content: 0.0079 mol / g) were added.

[0182] [Chemistry 17]

[0183]

[0184] 0.34 parts, as a crosslinking agent, methylhydrogen polysiloxane (B-2-1) having a molecular chain end-capped with trimethylsiloxy groups and having SiH groups in the side chains (polymerization degree 64, dimethylsiloxane-methylhydrogen siloxane copolymer having trimethylsiloxy groups end-capped at both ends of the molecular chain 0.0113 mol / g), 1.15 parts, dimethyl polysiloxane (B-2-2) having a molecular chain end-capped with dimethylhydrogen siloxy groups and having no Si-H groups in the side chains (average polymerization degree 20, Si-H group amount 0.0014 mol / g), 0.23 parts, a benzotriazole derivative (D1) represented by the following formula (2)

[0185] [Chemistry 18]

[0186]

[0187] 0.13 parts (benzotriazole derivative / Pt atom=48 mol / mol), 0.04 parts (alkyne / Pt atom=38 mol / mol) of ethynylcyclohexanol (E1) as a reaction control agent were added, and stirred for 15 minutes. Next, 0.17 parts of a toluene solution (C1) of a complex of platinum and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane (platinum atom 1 mass%) were added, and stirred for 30 minutes to obtain a uniform silicone rubber compound A.

[0188] It should be noted that in the mixture, the ratio of Si-H groups of the components (B-1) and (B-2) relative to the total Si-H groups in the mixture as a whole was 15 mol% for the component (B-1) and 85 mol% for the component (B-2). In addition, the molar ratio of the total amount of Si-H groups to the total amount of vinyl groups in the entire composition (Si-H groups / vinyl groups) was 2.4.

[0189] The curability of the silicone rubber compound A at 110° C. was measured using a rheometer MDR2000 (manufactured by Alpha Technologies). The results are shown in Table 1.

[0190] Furthermore, after mixing the silicone rubber compound A, the shear rate 0.9 s was measured after standing at 25°C for 10 minutes and after standing at 25°C for 24 hours. -1 Viscosity η0 and η 24 , and the results are recorded in Table 1.

[0191] Table 1 shows the results of measuring compression set of the cured product obtained by press-curing at 120° C. for 15 minutes.

[0192] In addition, a PC (polycarbonate) test piece (about 25×50 mm) was placed in a mold (about 50 mm×70 mm), and the above-mentioned silicone rubber composition A (about 4 to 20 g) was placed on top of it, and pressurized curing was performed at 110°C for 5 minutes (rubber thickness 1 to 3 mm). The integrated molded product was peeled off by hand, and the adhesion was evaluated by the cohesive failure rate [rubber failure rate = the ratio (%) of the area without interface peeling and rubber failure (cohesive failure) relative to the entire area of ​​the bonding interface]. The results are also shown in Table 1.

[0193] [Example 2]

[0194] To 100 parts of silicone rubber base material A, 6.31 parts of dimethylpolysiloxane (A1) having an average degree of polymerization of 220 and end-capped with dimethylvinylsiloxy groups at both ends of the molecular chain, 5.64 parts of dimethylpolysiloxane (A2) having an average degree of polymerization of 200 and end-capped with trimethylsiloxy groups at both ends of the molecular chain and 5 mol% of the methyl groups in the side chain being vinyl groups, 0.33 parts of the adhesion aid (B-1) having a phenylene skeleton of Example 1, 1.09 parts of methylhydrogenpolysiloxane (B-2-1) having SiH groups in the side chains and end-capped with trimethylsiloxy groups at both ends of the molecular chain as a crosslinking agent, and 0.13 parts of a benzotriazole derivative (D1) (benzotriazole derivative / Pt atom=48 mol / mol) were added, and 0.03 parts of ethynylcyclohexanol (E1) (alkyne / Pt atom=32 mol / mol) as a reaction control agent were added, and stirred for 15 minutes. Next, 0.17 parts of a toluene solution (C1) of a complex of platinum and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane was added and stirred for 30 minutes to prepare a uniform silicone rubber compound B. The same evaluation as in Example 1 was performed and the results are shown in Table 1.

[0195] It should be noted that in the mixture, the ratio of Si-H groups of the components (B-1) and (B-2) relative to the total Si-H groups in the mixture as a whole was 16 mol% for the component (B-1) and 84 mol% for the component (B-2). In addition, the molar ratio of the total amount of Si-H groups to the total amount of vinyl groups in the entire composition (Si-H groups / vinyl groups) was 2.1.

[0196] [Example 3]

[0197] In Example 1, the benzotriazole derivative D1 is replaced by a benzotriazole derivative (D2) represented by the following formula (3):

[0198] [Chemistry 19]

[0199]

[0200] The same formulation as in Example 1 was used to prepare a silicone rubber compound C except that 0.20 parts (benzotriazole derivative / Pt atom=48 mol / mol) was used, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

[0201] [Comparative Example 1]

[0202] Table 1 shows the results of preparing a silicone rubber compound D by using the same formulation as in Example 1 except that the benzotriazole derivative (D1) was not added and evaluating the same method as in Example 1.

[0203] [Comparative Example 2]

[0204] In Example 1, except that the amount of the adhesion promoter (B-1) having a phenylene skeleton was adjusted to 1.33 parts, the amount of the methylhydrogen polysiloxane (B-2-1) having SiH groups in the side chains and capped at both ends of the molecular chain with trimethylsiloxy groups as a crosslinking agent was adjusted to 0.57 parts, and the amount of the dimethyl polysiloxane (B-2-2) having no Si-H groups in the side chains and capped at both ends with dimethylhydrogen siloxy groups was adjusted to 0.33 parts, the silicone rubber compound E was prepared by using the same formulation, and the results of the evaluations performed in the same manner as in Example 1 are shown in Table 1. In this mixture, the ratio of Si-H groups of the component (B-1) to the total amount of Si-H groups in the entire mixture was 58 mol% for the component (B-1) and 42 mol% for the component (B-2). In addition, the molar ratio of the total amount of Si-H groups to the total amount of vinyl groups in the entire composition (Si-H groups / vinyl groups) was 2.4.

[0205] [Comparative Example 3]

[0206] In Example 1, except that the adhesion promoter (B-1) having a phenylene skeleton was not contained, and as a crosslinking agent, 1.46 parts of methylhydrogen polysiloxane (B-2-1) having a SiH group in the side chain and capped at both ends with trimethylsiloxy groups, and 0.30 parts of dimethyl polysiloxane (B-2-2) having a Si-H group in the side chain and capped at both ends with dimethylhydrogen siloxy groups, were used, a silicone rubber compound F was prepared with the same formulation, and the same evaluation as in Example 1 was performed, and the results are shown in Table 1. In addition, the molar ratio of the total Si-H group amount to the total vinyl group amount (Si-H group / vinyl group) of the entire composition was 2.4.

[0207] [Comparative Example 4]

[0208] In Example 1, except that 0.054 parts of benzotriazole (benzotriazole / Pt atom = 18 mol / mol) was added instead of the benzotriazole derivative (D1), silicone rubber compound G was prepared using the same formulation and the same evaluation results as in Example 1 are shown in Table 1.

[0209] [Comparative Example 5]

[0210] In Example 1, except that 0.003 parts of benzotriazole (benzotriazole / Pt atom = 1 mol / mol) was added instead of the benzotriazole derivative (D1), silicone rubber compound H was prepared using the same formulation and the same evaluation results as in Example 1 are shown in Table 1.

[0211] [Table 1]

[0212]

[0213] ○: Cohesive failure rate more than 90%

[0214] ×: Cohesive failure rate 0% (no adhesion).

Claims

1. An addition-curing self-adhesive silicone rubber composition comprising: (A) 100 parts by mass of an alkenyl group-containing organopolysiloxane having at least two alkenyl groups bonded to a silicon atom in one molecule, (B-1) 0.05 to 10 parts by mass of an organic silicon compound having at least one phenylene skeleton and at least one hydrogen atom bonded to the silicon atom and having 1 to 100 silicon atoms in one molecule, (B-2) an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to silicon atoms in one molecule and containing no aromatic groups: 0.2 to 30 parts by mass, in an amount such that the number of moles of Si-H groups in each of the components (B-1) and (B-2) relative to the total number of moles of hydrogen atoms (Si-H groups) bonded to silicon atoms in the components (B-1) and (B-2) (total Si-H groups) is [Si-H groups (B-1)] / [total Si-H groups]=1 to 25 mol%, [Si-H groups (B-2)] / [total Si-H groups]=75 to 99 mol%, (C) platinum-based catalyst: 0.5 to 500 ppm in terms of platinum metal mass relative to the total mass of components (A), (B-1) and (B-2), (D) a benzotriazole derivative represented by the following general formula (I): 2 to 100 mol per 1 mol of platinum atoms of the component (C); [Chemistry 1] In the formula, R 1 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, R 2 is a monovalent hydrocarbon group having 1 to 15 carbon atoms or a group represented by the following formula (I'), [Chemistry 2] In the formula, R 3 -(CH2) a -Si(OR 4 )3, R 4 is an alkyl group with 1 to 4 carbon atoms or SiR 5 3 base, R 5 is an alkyl group having 1 to 4 carbon atoms, a is an integer of 1 to 6, and * represents a bonding point. (E) An acetylene alcohol compound or a compound obtained by modifying the alcoholic hydroxyl group of the compound with silane or siloxane: 1 to 500 mol of acetylene per 1 mol of platinum atoms of the component (C).

2. The addition-curing self-adhesive silicone rubber composition according to claim 1, wherein The molar ratio of the total Si-H groups to the total alkenyl groups in the silicone rubber composition, that is, the total alkenyl groups, is an amount such that [total Si-H groups] / [total alkenyl groups]=2.0 to 3.

0.

3. The addition-curing self-adhesive silicone rubber composition according to claim 1, wherein The (F) component further contains 5 to 100 parts by mass of a reinforcing silica fine powder based on 100 parts by mass of the (A) component.

4. The addition-curing self-adhesive silicone rubber composition according to claim 3, wherein The specific surface area of ​​component (F) according to the BET method is 50 m 2 / g or more of fumed silica.

5. An addition-curing self-adhesive silicone rubber composition, wherein: The silicone rubber composition according to claim 1 is uniformly mixed, and the shear rate is 0.9 s after standing at 25° C. for 10 minutes and 24 hours. -1 The viscosities under 24 When η 24 / η0≤2.

6. A silicone rubber cured product obtained by curing the silicone rubber composition according to any one of claims 1 to 5, wherein the compression set after compression at a compression rate of 25% and at 150°C for 22 hours is 30% or less.

Images