JPH08291254A - Silicone adhesive composition - Google Patents

Abstract

PURPOSE: To obtain a composition having excellent adhesivity to a hardly adhesive resin such as an acrylic resin and readily releasable from a mold by using an addition-curing type silicone rubber composition. CONSTITUTION: This composition contains (A) 100 pts.wt. of a diorganopolysiloxane containing at least two aliphatic unsaturated groups in one molecule and having 10-10000000cp viscosity at 25 deg.C, (B) 0-30 pts.wt. of an organohydrogen polysiloxane containing at least two hydrogen atoms directly bonded to silicon atoms in one molecule, (C) 0.1-20 pts.wt. of a compound containing at least two structural units derived from one or more than two kinds of polymerizable olefin monomers in one molecule and containing at least one hydrogen atom directly bonded to silicon atom in one molecule and (D) a platinum-group metal compound in an amount of 1-2000ppm as a metal atom based on total amount of components (A), (B) and (C).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a silicone adhesive composition, particularly an addition-curable silicone rubber composition,
Acrylic resin and A, which were difficult to bond with conventional compositions
The present invention relates to a composition with improved adhesiveness that can be integrally molded with BS resin and the like.

[0002]

2. Description of the Related Art Heretofore, many methods have been proposed for adhering an addition-curable silicone rubber and a thermoplastic or thermosetting organic resin. For example, a method of applying a primer to the surface of a resin molded product and then applying and curing an uncured silicone rubber composition to adhere the same, a method of contacting the surface of the resin molded product with a self-adhesive silicone rubber composition and curing the same. Is proposed. Many techniques have been proposed for this self-adhesive silicone rubber composition, in which the adhesion-imparting component is the skeleton. As the adhesiveness imparting component, for example, a compound having at the same time an epoxy group and a hydrogen atom directly connected to a silicon atom in one molecule (Japanese Patent Publication No. 51-33540).
No., Japanese Patent Publication No. 53-13508), a compound having at the same time an alkoxysilyl group and a hydrogen atom directly connected to a silicon atom in one molecule (see Japanese Patent Publication Nos. 58-26376 and 53-21026). ) Etc. are mentioned as a typical thing. In addition, an attempt was made to add an organohydrogenpolysiloxane containing 30 mol% or more of hydrogen atoms directly bonded to silicon atoms to the organic resin side to bond it with an addition-curable silicone rubber (see Japanese Patent Publication No. 2-34311), organic. Integration of silicone rubber to resin by physical fitting method (Japanese Patent Publication No. 63-452)
No. 92), a method in which a silicone rubber is bonded and integrated to an olefin resin grafted with a compound having an aliphatic unsaturated group and a silicon atom-bonded hydrolyzable group (JP-A-63-1).
No. 83843) is proposed.

[0003]

However, the method of adhering by using a primer is inferior in workability because it takes time and effort to take out a resin molded product once molded from a mold or the like and apply a primer to it. The method of adding polysiloxane to the organic resin may change the characteristics of the resin itself because it is added siloxane, and it may be difficult to obtain the original characteristics. There was a fear that the mating could be disengaged due to physical force. The method of using an olefin resin grafted with a compound having an aliphatic unsaturated group and a silicon atom-bonded hydrolyzable group has a drawback that a primer is required for integration with an addition-curable silicone rubber. Therefore, the most practically effective one is the self-adhesive type adhesive, but the conventional self-adhesive type addition-curable silicone rubber composition has sufficient adhesive force to the acrylic resin and ABS resin. Not not. Although the condensation-curable silicone rubber adhesive composition can be easily adhered to such a resin, it takes a long time to cure and there is an economical problem in the production of industrial products. On the other hand, due to various characteristics of silicone rubber such as weather resistance, heat resistance, cleanliness, and rubber elasticity, in recent years, the demand for integrally molding an organic resin and silicone rubber under a short-time curing condition has been increasing, and compression There has been a demand for an addition-curable silicone rubber composition that can be molded integrally with an acrylic resin or an ABS resin by molding or injection molding.

In view of the above situation, the object of the present invention is the following two points. The first is acrylic, which has poor adhesiveness with conventional addition-curable silicone rubber compositions,
It is to provide a novel addition-curable silicone rubber composition having good adhesion to a resin such as ABS.
The second is to provide a silicone rubber composition which is excellent in adhesiveness as described above, and is also excellent in mold releasability in which the silicone rubber itself is peeled from the mold with sufficient practicality.

[0005]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have arrived at the silicone adhesive composition of the present invention as a solution to the problems. This silicone adhesive composition has: A) a composition represented by the average composition formula R ¹ _a SiO _{(4-a) / 2} and containing at least two aliphatic unsaturated groups in one molecule, and has a viscosity at 25 ° C.
Diorganopolysiloxane having 10 to 10,000,000 centipoise: 100 parts by weight (wherein R ¹ represents an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 1.8
It is a positive number ≦ a <2.3. ) B) Organohydrogenpolysiloxane represented by the average composition formula R ² _b H _c SiO _{(4-bc) / 2} and containing a hydrogen atom directly bonded to at least two silicon atoms in one molecule: 0 to 30 Parts by weight, (wherein R ² represents an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and b and c are each 0.002
It is a positive number that satisfies ≦ c ≦ 1, 1.6 <b <2.2 and 1.8 <b + c ≦ 3.0. ) C) Containing at least two structural units derived from one or more olefin-polymerizable monomers in one molecule,
Further, an organic silicon compound containing at least one hydrogen atom directly connected to a silicon atom in one molecule and having a softening point or a melting point of 120 ° C. or less: 0.1 to 30 parts by weight (however,
The amount by which the hydrogen atom directly connected to the silicon atom supplied from the components B) and C) becomes 0.4 to 10 mol per 1 mol of the total aliphatic unsaturated group supplied from the component in the composition. ) And D) Platinum group metal compound: A metal atom is contained in an amount of 1 to 2,000 ppm with respect to the total amount of the components A), B) and C).

The present invention will be described in more detail below. The diorganopolysiloxane of component A) used in the present invention is represented by the average composition formula R ¹ _a SiO _{(4-a) / 2} and contains at least two aliphatic unsaturated groups in one molecule. Viscosity at ℃ 10-10,000,000 centipoise, preferably 100-
1,000,000 centipoise, especially 1,000-100,000 centipoise. As the component A), a diorganopolysiloxane which is generally used as a main raw material for addition-curable silicone rubber compositions can be used. R ¹ in the above formula is an aliphatic unsaturated group such as an alkenyl group having 2 to 8 carbon atoms such as a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a hexenyl group and a cyclohexenyl group. Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group,
Alkyl groups such as t-butyl group, pentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, nonyl group, decyl group; aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group; benzyl group, phenyl An aralkyl group such as an ethyl group; or a chloromethyl group, a chloropropyl group, a bromoethyl group, in which a part of hydrogen atoms of these groups are substituted with a halogen atom such as fluorine, chlorine or bromine, 3,
1 to 10 carbon atoms such as 3,3-trifluoropropyl group,
Preferably, it represents an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and a is a positive number satisfying 1.8 ≦ a <2.3. R ¹ may be different or the same within the above range. The diorganopolysiloxane may be linear or branched containing R ¹ SiO _3/2 units or SiO _4/2 units, but usually the main chain portion is basically
It _consists of repeating R ¹ ₂ SiO _2/2 units and the end of the chain is R ¹ ₃ S.
It is generally a straight-chain type which is blocked with iO _1/2 units. R ¹ may be basically any of the above, but it is preferable to introduce a vinyl group as the aliphatic unsaturated group and a methyl group or a phenyl group as the other group. Further, the aliphatic unsaturated group such as an alkenyl group may be bonded to a silicon atom in the middle of the molecular chain or may be bonded to a silicon atom at the end of the molecular chain. From the viewpoint of physical properties and the like, it is preferable to have at least an alkenyl group bonded to a silicon atom at the end of the molecular chain. As this diorganopolysiloxane, those produced by a method known to those skilled in the art can be used. This production method generally involves equilibrating an organocyclopolysiloxane and a hexaorganodisiloxane in the presence of an alkali or acid catalyst.

The component (B), an organohydrogenpolysiloxane used in the present invention, has an average compositional formula R ² _b H _c SiO ^2.
_{It is represented by (4-bc) / 2} and contains at least two, preferably three or more, hydrogen atoms directly linked to silicon atoms in one molecule. The component B) functions as a cross-linking agent when the hydrogen atom (that is, SiH group) directly connected to the contained silicon atom reacts with the component A), and the molecular structure thereof is not particularly limited and is conventionally produced. For example, various ones such as linear, cyclic, branched or three-dimensional network structure can be used, but at least two, preferably three or more hydrogen atoms directly bonded to a silicon atom in one molecule are used. Must be included. R ² in the above formula has 1 carbon atom
To 10 carbon atoms, preferably 1 to 10 carbon atoms excluding aliphatic unsaturated bonds
8 is an unsubstituted or halogen-substituted monovalent hydrocarbon group, and examples thereof include the same ones exemplified as R ¹ above, and examples thereof include an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group. Group; aryl group such as phenyl group, tolyl group; aralkyl group such as benzyl group, phenylethyl group; alkenyl group such as vinyl group, allyl group, propenyl group, butenyl group; or 3,3,3-trifluoropropyl group And other halogen-substituted monovalent hydrocarbon groups. Other preferable groups and the like are the same as those of R ¹ , but it is particularly preferable that they do not contain an aliphatic unsaturated group such as an alkenyl group. b and c are 0.002 ≦ c ≦ 1, respectively
It is a positive number that satisfies 1.6 <b <2.2 and 1.8 <b + c ≦ 3.0. The hydrogen atom (SiH group) bonded to the silicon atom in component B) may be located at the end of the molecular chain or in the middle of the molecular chain, and the number of silicon atoms in one molecule is 3 It may be about 500, especially about 4 to 200.

This organohydrogenpolysiloxane can be obtained by a production method known to those skilled in the art. A very general production method is octamethylcyclotetrasiloxane and / or tetramethylcyclotetrasiloxane and hexamethyldisiloxane which can serve as an end group, 1,3-dihydro-1,1,3,3-
This is a method in which raw materials selected from tetramethyldisiloxane are combined and equilibrated at a temperature of about -10 to + 40 ° C in the presence of a catalyst such as sulfuric acid, trifluoromethanesulfonic acid or methanesulfonic acid. You can get it easily. The amount of this component added is 0 to 30 parts by weight, preferably 0.1 to 20 parts by weight, per 100 parts by weight of component A). The hydrogen atom (SiH group) directly connected to the silicon atom that reacts with the component A) is supplied from the component C) described below in addition to the component B). When the hydrogen atom (SiH group) directly connected to the silicon atom is supplied in an amount capable of curing the composition of the present invention only with the component C), this component need not be particularly added, but From the viewpoint, in order to make the physical properties of the elastomer sufficient, it is desirable to complement the hydrogen atom directly bonded to the silicon atom by the component B). If the added amount of component B) exceeds 30 parts by weight, the hydrogen atoms directly connected to the silicon atoms become excessive, causing foaming, and the physical properties after curing become too hard, or conversely too soft, and as an elastomer. It becomes impossible to obtain sufficient characteristics of. The preferable addition amount of this component B) is the hydrogen atom (SiH) bonded to the silicon atom in component B) relative to the aliphatic unsaturated group in component A).
The amount of (group) is 0.1 to 5 mol / mol, particularly 0.5 to 3 in molar ratio.
It can also be set to be mol / mol.

The compound of component C) used in the present invention is 1
Containing at least 2 structural units derived from one or more kinds of olefin-polymerizable monomers in one molecule, and further containing at least one hydrogen atom (SiH group) directly bonded to a silicon atom in one molecule Is. Here, the structural unit derived from the olefin-polymerizable monomer means at least one of the polymerizable functional groups contained in the olefin-polymerizable monomer.
Means that has already consumed the individual. Further, the number of Si-H groups in the component C) may be at least one in one molecule,
It is preferable to have two or more. By adding this compound, it becomes possible to adhere to an organic resin such as acrylic or ABS, and to impart a property of easily releasing from the metal mold.

Regarding the similar compound of the component C),
That an organopolysiloxane having a (meth) acryloxy group serves as an adhesion promoter for an addition-curable silicone rubber,
This compound, whose main chain is a diorganopolysiloxane, is taught in Japanese Patent Publication No. 4-22181, and as a thermoplastic resin, it can be bonded with a conventional adhesive as shown in the examples of the publication. It is only disclosed that the adhesiveness to PBT or polyester is excellent, and the thermoplastic resin such as acrylic and ABS, which is the object of the present invention, has been conventionally regarded as a difficult adhesive resin for addition-curable adhesives. It is insufficient for the purpose of firm adhesion to the. Further, Japanese Patent Laid-Open No. 4-68007 discloses a method for producing a compound contained in the component C) and discloses that it is effective as a primer component in adhesion of silicone rubber to an acrylic resin. Further, JP-A-5-25292 discloses that a similar compound can be a useful primer in adhesion of silicone rubber to a metal. However, those using these compounds as a primer do not have sufficient durable adhesiveness, and their use as an adhesion-imparting component blended in a self-adhesive silicone rubber composition is not disclosed. Furthermore,
The present inventors have surprisingly found that when the component C) used in the present invention is a component of the silicone adhesive composition of the present invention, this composition does not adhere to a metal such as a mold unexpectedly. It has been found that the adhesive adheres only to these, but such characteristics are not disclosed or suggested.

The olefin-polymerizable monomer which can be used for producing the compound of the component C) has an aliphatic unsaturated bond which can be polymerized by active species such as radicals, cations and anions. It may be one used as a raw material. Typical examples are acrylic acid and its ester, methacrylic acid and its ester, maleic acid, maleic anhydride, styrene, alkyl vinyl ether, vinyl polyoxyalkylene ether, vinyl silane, ethylene, propylene, butadiene, and derivatives thereof. Can be mentioned. Some or all of the hydrogen atoms of these compounds may be replaced with halogen atoms such as chlorine, bromine and fluorine.

The compound of component C) contains at least two structural units derived from the above-mentioned olefin-polymerizable monomer in one molecule, and the structure of this portion is represented by the general formula-[CH ₂ -C (R ³ ) (X)] _n- is preferably used. R ³ in the formula is a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group and may be different or the same, and examples thereof are the same as those of R ¹ . X is a hydrogen atom, a halogen atom such as fluorine, chlorine or bromine, a cyano group, an unsubstituted or substituted monovalent hydrocarbon group, or a formula-COO.
It is a group selected from the groups represented by R ⁴ , —OR ⁴ , —OCOR ⁴ , and — (CH ₂ ) _r SiR ⁵ ₃ . R ⁴ is a hydrogen atom, a hydroxyl group, an unsubstituted or substituted monovalent hydrocarbon group, the formula ^{_{- (CH 2 CHR 3 O)}} m R 5, - (CH 2) r S
It is selected from the group represented by iR ⁵ _3. R ⁵ is selected from a hydrogen atom, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, and an unsubstituted or substituted monovalent hydrocarbon group, and R ⁴ and R ^{5 each have} an unsubstituted or substituted monovalent hydrocarbon group. Examples of the group are the same as those for R ¹ . m is an integer of 1 to 10 and r is an integer of 0 to 10. In the above formula, the hydrogen atom may be optionally substituted with chlorine or fluorine atom.
n represents an integer of 2 or more, and the n repeating units may be head-to-tail bonds or head-to-head or tail-to-tail bonds. If this n is not 2 or more, sufficient adhesiveness is not expressed.

The structure of the portion containing a hydrogen atom (SiH group) directly connected to a silicon atom in the component C) is, for example, a linear, branched or cyclic organohydrogensiloxane as shown below. The structure is preferred.

Embedded image (In the formula, p is 0, 1, 2 or 3, and q is 1, 2 or 3.)

The addition amount of the compound of component C) is the same as that of component A).
0.1 to 30 parts by weight per 100 parts by weight, preferably 1 to 20
In the range of parts by weight, this also means that the total amount of hydrogen atoms (SiH groups) directly connected to the silicon atoms supplied from the components C) or B) and C) is the total amount of all components ( In particular 1) of the total amount of aliphatic unsaturated groups supplied from component A)
The amount can be 0.4 to 10 mol, preferably 1 to 5 mol, based on mol. When the amount of the component C) is less than 0.1 parts by weight (or the above molar ratio is less than 0.4), the adhesiveness is poor, and the composition is insufficiently cured and physical properties such as strength cannot be maintained. Further, if it is more than 30 parts by weight (or the above molar ratio is more than 10), foaming may occur, and disadvantageously the physical strength of the silicone rubber after curing becomes insufficient.

The compound as the component C) is an essential component for imparting adhesiveness to a resin having relatively poor adhesiveness such as acrylic resin and ABS resin, which is a characteristic of the silicone adhesive composition of the present invention, and has a softening point. Or the melting point is below 120 ℃
Although it is 100 ° C. or less, in order to more strongly develop the adhesiveness, the softening point or melting point of this compound is the thermoplastic or thermosetting organic resin to be adhered and the silicone adhesive composition of the present invention. It is preferable that the temperature is lower than the temperature at which and are heat-bonded. Specific examples of this compound include the following compounds.

[0016]

Embedded image (In the formula, n is an integer of 2 or more, and p and q are independently 0.
Or an integer of 1 or more, and the arrangement of p and q may be random)

[0017]

Embedded image [In the formula, R ⁶ is a hydrogen atom or a methyl group, and R ⁷ is a carbon atom of 1 to 8
Or an alkyl group of formula-(CH ₂ ) ₃ SiR ⁵ ₃ (wherein R ⁵ is the same as above), r is 0 or an integer of 1 or more, s is an integer of 1 or more, and r + s is It is an integer of 2 or more]

As an example of a method for synthesizing such a compound, for example, as a method for synthesizing a (meth) acrylic acid ester polymer, an acrylic acid ester or a methacrylic acid ester as disclosed in JP-A-4-68007 is used. Method of copolymerizing γ-methacryloxypropyltris (dimethylsiloxy) silane with a radical initiator such as azobisisobutyronitrile, U.S. Pat. No. 4,448,980, 4,417,
034 Specifications, J.MACROMOL.SCI.CHEM., A21 (8 & 9), pp.
Polymerization of methacrylic acid ester and γ-methacryloxypropyltris (dimethylsiloxy) silane using fluorine anion as an initiator using silyl ketene acetal as disclosed in 943-960 (1984) and the like. A method obtained by introducing an unsaturated group using so-called GTP (group transfer polymerization) and then adding tetramethylcyclotetrasiloxane by a hydrosilylation reaction, and a fat such as a lower alkenyl group such as a vinyl group or an allyl group. After a trialkoxysilane having a group unsaturated group (for example, vinyltrimethoxysilane, allyltrimethoxysilane, vinyltriethoxysilane, etc.) and acrylic acid (methacrylic acid) ester are polymerized by a radical initiator, the alkoxysilyl group Silicon by reaction Examples include a method of introducing a hydrogen atom directly connected to the child. It is possible to obtain a compound similar to the above from a monomer capable of radical polymerization by the same reaction. In addition, as an example of a compound having an aromatic ring, a polymer of α-methylstyrene (for example, a tetramer) is synthesized by living anionic polymerization of α-methylstyrene, and the end of the anion is blocked with allyl chloride, followed by tetra- A compound as described above can be obtained by a hydrosilylation reaction with methylcyclotetrasiloxane.

These compounds are effective compounds for adhering to the organic resin which is a characteristic of the composition of the present invention, but what is important here is that these compounds become liquid having a fluidity at 120 ° C. or lower. Is to do. Already JP 4-6800
No. 7 discloses that such a compound is effective as a primer component for an acrylic resin, however, it does not disclose the use as a self-adhesive component, and at least these compounds are not disclosed.
When it cannot be turned into a liquid liquid having fluidity at 120 ° C. or lower, it does not exhibit adhesiveness at all by being added to the silicone composition as in the present application. The composition of the present invention, by blending the component C) as described above, does not adhere to a metal such as a mold, and thus has an acrylic resin, ABS, which has been conventionally considered to have poor adhesion.
One of the features is that it selectively adheres to a thermoplastic resin containing a resin or the like. However, when adhesiveness to a metal is required depending on the application, the olefin polymerizable monomer can be used as the C) component. In addition to the derived structural unit and a hydrogen atom directly linked to a silicon atom, a trialkoxysilyl group-containing organic group such as γ-trimethoxysilylpropyl group and γ-triethoxysilylpropyl group, and γ-glycidoxypropyl Group, β- (3,4-epoxycyclohexyl)
By using a functional group such as an ethyl group containing an epoxy group-containing organic group introduced into the molecule, a composition excellent in durability and adhesiveness can be adhered to both thermoplastic resin and metal. You can

The platinum group metal compound of the component D) used in the present invention is used as a catalyst for promoting the addition curing reaction (hydrosilylation reaction) between the component A) and the components B) and / or C). It is used, but it may be one known to those skilled in the art. Therefore, examples thereof include platinum black, chloroplatinic acid, alcohol modified products of chloroplatinic acid, complexes of chloroplatinic acid with olefins, aldehydes, vinyl siloxanes, acetylene alcohols and the like. Furthermore, a rhodium compound such as Wilkinson's catalyst and a ruthenium compound can be used, but the use of a platinum compound is recommended from the economical point of view. It should be noted that this addition amount may be appropriately increased or decreased according to the desired curing speed,
Usually, the amount of platinum group metal relative to the total weight of components A), B), and C) is 1 to 2,000 ppm, preferably 1 to 200 ppm.

Further, when it is necessary to adjust the curing time in order to put the silicone adhesive composition of the present invention into practical use, a vinyl group-containing organopolysiloxane such as vinylcyclotetrasiloxane may be used as a catalyst control agent. A compound selected from the group consisting of triallyl isocyanurate, alkyl maleates, acetylene alcohols and their silanes, siloxane modified products, hydroperoxides, tetramethylethylenediamine, benzotriazole and mixtures thereof may be used.

Furthermore if strength necessary to impart to the silicone adhesive composition, specific surface area of 50 m ² / g or more measured by the BET method pulverulent silica (usually 50~400m about ² / g) It is effective to add it. Examples of such finely divided silica include, as hydrophilic silica, Aerosil 130,
200, 300 (Nippon Aerosil, Degussa), Cabosi
l MS-5, MS-7 (Cabot), Rheorosil QS-102, 103
(Tokuyama Soda Co., Ltd.), Nipsil LP (Nippon Silica Co., Ltd.) and the like. As a hydrophobic silica, Aerosil R-
812, R-812S, R-972, R-974 (Degussa), Rheorosil
Examples include MT-10 (manufactured by Tokuyama Soda Co., Ltd.) and Nipsil SS series (manufactured by Nihon Silica Co., Ltd.). Further, quartz powder, diatomaceous earth, non-reinforcing fillers such as calcium carbonate, inorganic pigments such as cobalt blue, colorants such as organic dyes, cerium oxide, zinc carbonate, manganese carbonate, red iron oxide, titanium oxide,
It is also possible to add a heat resistance improver such as carbon black or a flame retardant improver.

[0023]

EXAMPLES Examples of the present invention will be given below, but the present invention is not limited thereto. Example of preparation of silicone composition containing no component C): 100 parts by weight of dimethylpolysiloxane having both ends of the molecular chain blocked with dimethylvinylsilyl groups and having a viscosity of 10,000 centipoise at 25 ° C., specific surface area by BET method of 300 m 40 parts by weight of fumed silica ( ² / g), 8 parts by weight of hexamethyldisilazane, and 1 part by weight of water were placed in a kneader, and the mixture was stirred and mixed at room temperature for 1 hour, then heated to 150 ° C and kept warm for 2 hours. I went. Then, the mixture was cooled to room temperature, and the viscosity at 25 ° C, where both ends of the molecular chain were blocked with dimethylvinylsilyl groups, was 10,0.
Further, 20 parts by weight of the same dimethylpolysiloxane as described above, which is 00 centipoise, and the following formula

[Chemical 4] 3 parts by weight of methylhydrogenpolysiloxane having a viscosity of about 10 centipoise at 25 ° C represented by a vinyl group [-(CH ₂ = CH) (CH ₃ ) SiO-unit] directly bonded to a silicon atom 4 parts by weight of vinylmethylpolysiloxane containing 5 mol% of the number of silicon atoms in the molecule and having a viscosity of 1,000 centipoise at 25 ° C, is a kind of acetylene alcohol to extend the curing time at room temperature. 0.1 parts by weight of 3-methyl-3-ol-1-butyne and 50 ppm of platinum-vinylsiloxane complex as platinum atoms were added and mixed well until uniform. Using the composition obtained above, press into a sheet under curing conditions of 120 ° C / 10 minutes,
When mechanical properties of this sheet were measured according to the method of JIS K 6301, hardness (JIS A) 40, elongation 500%, tensile strength 100 kgf / cm ² , tear strength 35 kgf / cm.

Synthetic Example of Component C): Synthetic Example 1 Sodium mirror was prepared in a 1 L flask in advance under high vacuum, and 0.5 mol / L of α-methylstyrene T was added thereto.
500 ml of HF (tetrahydrofuran) solution was added. After stirring with a magnetic stirrer for 6 hours at room temperature, add 20 g of degassed allyl chloride under high vacuum and from room temperature.
The mixture was stirred for 6 hours while raising the temperature to 40 ° C. After returning the obtained solution to normal pressure, 5 ppm of platinum alcohol complex was added as a platinum atom and the temperature was raised to 100 ° C. 250 g of 1,3,5,7-tetramethylcyclotetrasiloxane was added dropwise using a dropping funnel over 4 hours, and then stirring was continued at 100 ° C. for 2 hours. This solution was stripped at 100 ° C under a reduced pressure of 2 mmHg, and a starch syrup-like transparent liquid substance was obtained at room temperature (25 ° C).
I got 120g. This viscous product was analyzed by IR and GPC to give the following formula

Embedded image Was estimated to be a mixture having an a / b molar ratio of about 3/1.

Synthesis Example 2 Isopropyl alcohol 5 dried in a 1 L flask.
00 ml was added and the temperature was kept at 60 ° C. The following formula using a dropping funnel

[Chemical 6] A compound represented by γ-methacryloxypropyltris (dimethylsiloxy) silane 50 g, toluene 50 ml,
0.6 g of azobisisobutyronitrile was added dropwise over 1 hour. After the dropping, the mixture was kept warm for 8 hours, and then the solution was stripped at 100 ° C. under a reduced pressure of 2 mmHg to obtain a starch syrup-like pale yellow transparent liquid, that is, a polymer represented by the following structural formula.

[Chemical 7] (In the formula, n represents the number of repetitions), 38 g was obtained. The average molecular weight of this product in terms of styrene by GPC was 1,020.

Synthesis Example 3 Isopropyl alcohol 5 dried in a 1 L flask.
00 ml was added and the temperature was kept at 60 ° C. Using a dropping funnel, a commercial product of methylmethacrylate distilled product 93g, γ-methacryloxypropyltris (dimethylsiloxy) silane 28g
And a solution of 6 g of azobisisobutyronitrile were added over 1 hour. After dripping, the mixture was kept warm for 8 hours and then the solution was stripped at 100 ° C. under reduced pressure of 2 mmHg, and a candy-like pale yellow transparent liquid substance at room temperature, that is, a copolymer represented by the following structural formula.

Embedded image (In the formula, m and n represent the number of repetitions of each) 70 g was obtained.

Synthesis Example 4 The following formula was added to a 300 ml flask.

[Chemical 9] 48 g of 2,4-diphenyl-4-methyl-1-pentene represented by and alcohol-modified chloroplatinic acid (50 ppm) were charged as platinum atoms and maintained at 60 ° C. Trimethoxysilane 4
0 g was added dropwise using a dropping funnel over 1 hour. After the dropwise addition, the mixture was kept warm for 2 hours and then stripped at 100 ° C. under a reduced pressure of 2 mmHg. The obtained reaction product is diethyl ether
It was dissolved in 100 ml, and 50 ml of 5% by weight hydrochloric acid water and 150 g of tetramethyldisiloxane were added, and the mixture was stirred overnight while keeping the temperature below 20 ° C. After the reaction mixture was separated and dried over anhydrous sodium sulfate, the filtrate was stripped under reduced pressure of 2 mmHg at 40 ° C. to obtain 78 g of a candy-like pale yellow transparent liquid at room temperature. As a result of identification of this product, it was confirmed to be a compound having the following structural formula.

[Chemical 10]

Synthetic Example 5 100 g of dimethylpolysiloxane having a viscosity of 1,000 centistokes at 25 ° C. in which both ends of a molecular chain were blocked with vinyldimethylsiloxy groups in a 1 L flask, 93 g of a commercial methyl methacrylate distillation product, γ- Methacryloxypropyl tris (dimethylsiloxy) silane 28g, the following formula

[Chemical 11] 2.5 g of γ-methacryloxypropyltrimethoxysilane and 0.6 g of t-butylperbenzoate represented by the following formula were charged and the temperature was raised to 100 ° C. with good stirring. After keeping at 100 ° C for 5 hours, it was stripped under reduced pressure of 2 mmHg, and white liquid at room temperature, that is, a copolymer represented by the following structural formula.

[Chemical 12] (In the formula, m, n, p, q, and r represent the respective numbers of repetitions).

Synthesis Example 6 500 ml of dried toluene was placed in a 1 L flask and the temperature was kept at 60 ° C. Using a dropping funnel, a solution prepared by mixing 93 g of a commercial product of methyl methacrylate, 28 g of γ-methacryloxypropyltris (dimethylsiloxy) silane and 0.6 g of azobisisobutyronitrile was added over 1 hour. After dropping, incubate for 8 hours and then add 200 ml of this solution.
The solution was concentrated to 1, and the precipitate formed by dropping in a large excess of methanol was collected by filtration and then dried. This was a white powdery solid. When this compound was left on a hot plate at 120 ° C, it did not show fluidity. On the other hand, when this compound was dissolved in toluene to prepare a 1% by weight solution, it was easily dissolved at 25 ° C. to form a transparent and uniform solution.

Example 100 g of the liquid silicone rubber composition obtained in the preparation example of the silicone composition containing no component C) was added with the components C) obtained in Synthesis Examples 1 to 6 in the types shown in Table 1, respectively. 0.5 g
(1.0 g obtained in Synthesis Example 5) added (Examples 1 to 5, Comparative Example 3), 0.5 g of γ-methacryloxypropyltris (dimethylsiloxy) silane added (Comparative Example 1) And 0.5 g of γ-methacryloxypropyltrimethoxysilane were added (Comparative Example 2),
Each was well mixed by stirring to obtain an adhesive silicone rubber composition. These compositions are poured into an object to be adhered having a material shown in Table 1 placed in a press molding frame in advance so as to have an area of width 25 mm x length 50 mm, and the press pressure is 10 kg / cm ² , 80
A test piece is prepared by heat-curing under the molding condition of ℃ for 30 minutes,
When this test piece was subjected to shear fracture by a tensile test, the results shown in Table 1 were obtained. Separately, 1 g of the product obtained in Synthesis Example 6 was dissolved in 100 g of toluene, applied to a material to be adhered as shown in Table 1 as a primer, and air-dried to volatilize the solvent, and then the component C) was added. Similarly, a silicone rubber composition was pressed to prepare a test piece, and the results shown in Table 1 were obtained. (Comparative Example 4) The test piece was a strip of silicone rubber having a width of 25 mm and a thickness of 2 mm, and the adherend had a strip of 25 mm in width, and one end of each was bonded with an area of width 25 mm x length 50 mm and sheared. It is designed so that a tensile test can be performed. For evaluation of the adhesion state,
After observing the state after the tensile test, the one in which the silicone rubber has broken is bonded (○), the one that peels from the interface with the adherend but has a strong resistance adheres (△), and the one that easily peels It was judged as peeling (x).

[0031]

[Table 1]

These results show that the composition of the present invention adheres to the thermoplastic resin and is unlikely to adhere to the metal. Although the component C) obtained in Synthesis Example 5 contains a trialkoxysilyl group in the molecule, it also exhibits adhesiveness with a metal.
Adhesiveness was also recognized with respect to ABS and acrylic resin, which have conventionally been considered to have poor adhesiveness. Since the compound obtained in Synthesis Example 6 has a high softening point, it does not exhibit sufficient adhesiveness when added to the silicone rubber composition. On the other hand, when the product obtained in Synthesis Example 6 was used as a primer, the adhesive property was improved even though it did not have a trialkoxysilyl group effective for adhesion to a metal as in Synthesis Example 5. No selectivity was found for the film and it showed good adhesion to metals.

[0033]

Industrial Applicability According to the present invention, a novel addition-curable silicone rubber composition having good adhesion to acrylic resins, ABS resins and the like, which have poor adhesion with the addition-curable silicone rubber composition, is provided. Moreover, this composition has good releasability of the cured rubber from the mold and is suitable for integral molding with the resin.

Claims (2)

[Claims] 1. An average composition formula R ¹ _a SiO 2 _{(4-a) / 2}
Contains at least two aliphatic unsaturated groups in the molecule 25
Diorganopolysiloxane having a viscosity of 10 to 10,000,000 centipoise at 100 ° C .: 100 parts by weight (wherein, R ¹ represents an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 1.8 ≦ a <2.3 is a positive number.) B) Average composition formula R ² _b H _c SiO _{(4-bc) / 2} , containing at least two hydrogen atoms directly bonded to one silicon atom in one molecule. Organohydrogenpolysiloxane: 0 to 30 parts by weight, where R ² represents an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and b and c are each 0.002
It is a positive number that satisfies ≦ c ≦ 1, 1.6 <b <2.2 and 1.8 <b + c ≦ 3.0. ) C) Containing at least two structural units derived from one or more olefin-polymerizable monomers in one molecule,
Further, an organic silicon compound containing at least one hydrogen atom directly connected to a silicon atom in one molecule and having a softening point or a melting point of 120 ° C. or less: 0.1 to 30 parts by weight (however,
The amount by which the hydrogen atom directly connected to the silicon atom supplied from the components B) and C) becomes 0.4 to 10 mol per 1 mol of the total aliphatic unsaturated group supplied from the component in the composition. ) And D) Platinum group metal compound: A silicone adhesive composition containing an amount of 1 to 2,000 ppm as a metal atom relative to the total amount of components A), B) and C). 2. The composition according to claim 1, wherein the structural unit derived from the olefin-polymerizable monomer in the organosilicon compound as the component C) is derived from an acrylic acid ester or a methacrylic acid ester or a derivative thereof.