JP4634866B2 - Addition reaction curable silicone rubber adhesive - Google Patents

Description

  The present invention relates to an adhesive for addition reaction curable silicone rubber that adheres well to addition reaction curable silicone rubber and is excellent in storage stability.

  Silicone rubber is excellent in water repellency, weather resistance, heat resistance and the like, and is therefore used as a coating agent and film forming agent for various substrates. However, silicone rubber has a problem that it is difficult to adhere. Therefore, Patent Document 1 proposes an adhesive for silicone rubber comprising a polyorganosiloxane having a silicon atom-bonded alkenyl group and a silicon atom-bonded alkoxy group or silanol group, a condensation reaction catalyst, and an organic peroxide. Further, in Patent Document 2, silicone-coated cloths are stacked, and a platinum-based catalyst-containing addition reaction curing type or organic peroxide-containing radical reaction curing type silicone rubber adhesive that is plastic at room temperature is interposed in the stacking part. Thereafter, a method of heat-curing or heat-curing while pressure bonding has been proposed. In particular, Patent Document 2 describes an addition reaction curable silicone rubber adhesive containing a platinum-based catalyst, but this adhesive does not exhibit sufficient adhesion to the addition reaction curable silicone rubber. There was a problem.

Patent Document 3 discloses an addition reaction curable silicone composition containing calcium carbonate powder as an adhesive for silicone rubber. In particular, when the composition contains untreated heavy calcium carbonate powder or light (or precipitated) calcium carbonate powder surface-treated only with a treatment agent such as fatty acid or resin acid, these calcium carbonate powders are platinum. There is a problem that the composition becomes poisonous to the group metal catalyst and the composition is delayed in curing or does not cure over time.
JP-A-61-278580 JP 62-90369 A JP 2002-285130 A

  In view of the above-mentioned problems of the prior art, an object of the present invention is to provide an addition reaction curable silicone rubber adhesive that adheres well to an addition reaction curable silicone rubber and has excellent storage stability. It is.

As a means for achieving the above object, the present invention provides:
(A) 100 parts by mass of an organopolysiloxane containing at least two alkenyl groups bonded to silicon atoms and having a viscosity at 23 ° C. of 0.05 to 1,000 Pa · s,
(B) R ³ ₂ HSiO _1/2 units having hydrogen atoms bonded to silicon atoms only at both ends of the molecular chain [wherein R ³ is independently an unsubstituted or substituted monovalent group that does not contain an aliphatic unsaturated bond. Represents a hydrocarbon group. And a linear organohydrogenpolysiloxane having a viscosity at 23 ° C. of 0.001 to 100 Pa · s,
(C) containing at least three hydrogen atoms bonded to a silicon atom, an R ³ HSiO unit and an R ³ ₂ XSiO _1/2 unit [wherein R ³ is as described above, and X is a hydrogen atom or R ³ Represents. Any one of both, and an organohydrogenpolysiloxane having a viscosity at 23 ° C. of 0.001 to 100 Pa · s,
(D) 1 to 100 parts by mass of finely divided silica having a specific surface area of 50 m ² / g or more, and (E) an effective amount of a platinum group metal catalyst,
Containing
The total amount of hydrogen atoms bonded to silicon atoms in the components (B) and (C) is 0.01 to 20 mol per mol of alkenyl groups bonded to silicon atoms in all adhesives, and B) and addition reaction curable type wherein the ratio of the amount of hydrogen atoms bonded to silicon atoms in component (C) to the total amount of hydrogen atoms bonded to silicon atoms in component (C) is 5-98 mol% An adhesive for silicone rubber is provided.

  The adhesive of the present invention is useful as an adhesive for addition reaction curable silicone rubber because it adheres well to addition reaction curable silicone rubber and is excellent in storage stability.

  Hereinafter, the present invention will be described in detail.

[Component (A)]
Component (A) is an organopolysiloxane containing at least two alkenyl groups bonded to silicon atoms and having a viscosity at 23 ° C. of 0.05 to 1,000 Pa · s. Component (A) is a base polymer of the adhesive of the present invention. (A) A component may be used individually by 1 type, or may be used in combination of 2 or more type.

  The molecular structure of the component (A) is not particularly limited, and examples thereof include a linear structure, a partially branched linear structure, a branched chain structure, a cyclic structure, and a branched cyclic structure. The component (A) is usually preferably a substantially linear organopolysiloxane. Specifically, the molecular chain mainly consists of repeating diorganosiloxane units, and both ends of the molecular chain are triorgano. A linear diorganopolysiloxane blocked with a siloxy group is preferred. The component (A) may be a polymer composed of a single siloxane unit or a copolymer composed of two or more siloxane units. Further, the position of the alkenyl group bonded to the silicon atom in the component (A) is not particularly limited, and the alkenyl group is bonded only to one of the silicon atom at the molecular chain end portion and the silicon atom at the molecular end non-terminal portion. Or may be bonded to both of them.

  The viscosity of component (A) at 23 ° C. is usually 0.05 to 1,000 Pa · s, preferably 0.1 to 500 Pa · s. If the viscosity is too low, it may be difficult to sufficiently satisfy the physical properties and adhesiveness of the cured product of the obtained adhesive. On the other hand, if the viscosity is too high, the resulting adhesive is likely to be extremely poor in fluidity and poor in workability.

As the component (A), for example, the following average composition formula (1):
R ¹ _m R ² _n SiO _{(4-mn) / 2} (1)
Wherein R ¹ independently represents an unsubstituted or substituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond, R ² independently represents an alkenyl group, and m is usually from 0.7 to 2.2, preferably 1.8-2.1, more preferably 1.95-2.0, and n is usually 0.0001-0.2, preferably 0.0005-0. 1, more preferably a number of 0.01 to 0.05, provided that m + n is usually 0.8 to 2.3, preferably 1.9 to 2.2, more preferably 1.98 to 2. .05 number.)
An organopolysiloxane containing at least two alkenyl groups bonded to silicon atoms and having a viscosity at 23 ° C. of usually 0.05 to 1,000 Pa · s, preferably 0.1 to 500 Pa · s Is mentioned.

Examples of R ¹ include an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms and not containing an aliphatic unsaturated bond. Specific examples of R ¹ include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group, octyl group, decyl group; phenyl group, tolyl group Aryl groups such as xylyl group and naphthyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aralkyl groups such as benzyl group, 2-phenylethyl group and 3-phenylpropyl group; carbon atoms in these hydrocarbon groups A part or all of the hydrogen atoms bonded to is a halogen atom such as a chlorine atom, a bromine atom or an iodine atom; a group substituted by a cyano group, such as a chloromethyl group, a 2-bromoethyl group, 3, 3, 3- A trifluoropropyl group, a cyanoethyl group, etc. are mentioned.

Among these, a methyl group, a phenyl group, or a combination of both is preferable. This is because the component (A) in which R ¹ is a methyl group, a phenyl group, or a combination of both is easy to synthesize and has good chemical stability. When an organopolysiloxane having particularly good solvent resistance is to be used as the component (A), R ¹ is further a methyl group, a phenyl group, or a combination of both, and 3,3,3-trifluoropropyl. A combination with a group is preferred.

Examples of R ² include alkenyl groups having 2 to 8 carbon atoms. Specific examples of R ² include a vinyl group, an allyl group, a 1-propenyl group, an isopropenyl group, a 1-butenyl group, an isobutenyl group, and a hexenyl group. Among these, a vinyl group is preferable. This is because the component (A) in which R ² is a vinyl group is easy to synthesize and has good chemical stability.

  Specific examples of the component (A) include molecular chain both ends trimethylsiloxy group-capped dimethylsiloxane / methylvinylsiloxane copolymer, molecular chain both ends trimethylsiloxy group-capped methylvinylpolysiloxane, molecular chain both ends trimethylsiloxy group-capped dimethyl Siloxane / methylvinylsiloxane / methylphenylsiloxane copolymer, dimethylpolysiloxane blocked with dimethylvinylsiloxy group at both ends of molecular chain, dimethylvinylsiloxy group-blocked methylvinylpolysiloxane with molecular chain at both ends, dimethylvinylsiloxy group-blocked dimethyl with molecular chain at both ends Siloxane / methyl vinyl siloxane copolymer, both ends of molecular chain dimethyl vinyl siloxy group blocked dimethyl siloxane / methyl vinyl siloxane / methyl phenyl siloxane copolymer, tri chain siloxy at both ends of molecular chain Dimethylpolysiloxane and the like. These organopolysiloxanes may be used alone or in combination of two or more.

[(B) component]
The component (B) is a hydrogen atom bonded to a silicon atom, R ³ ₂ HSiO _1/2 unit only at both ends of the molecular chain [wherein R ³ is independently unsubstituted or substituted without an aliphatic unsaturated bond Represents a monovalent hydrocarbon group. And a linear organohydrogenpolysiloxane having a viscosity at 23 ° C. of 0.001 to 100 Pa · s. That is, the component (B) contains one SiH group at each end of the molecular chain (that is, two in one molecule) and does not contain a SiH group at the non-terminal portion of the molecular chain. (B) A component may be used individually by 1 type, or may be used in combination of 2 or more type.

  The component (B) is combined with the component (C) to form a curing agent for the adhesive of the present invention. The component (B) increases the molecular chain length of the component (A) when the adhesive of the present invention is cured, and greatly affects the adhesiveness of the adhesive of the present invention to silicone rubber.

Examples of R ³ include an unsubstituted or substituted monovalent hydrocarbon group having preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms and not containing an aliphatic unsaturated bond. Specific examples of R ³ include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl and hexyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; phenyl groups, tolyl groups and xylyl groups. Aryl groups such as naphthyl group; aralkyl groups such as benzyl group and phenethyl group; halogen-substituted alkyl groups such as 3,3,3-trifluoropropyl group and 3-chloropropyl group.

  The viscosity of the component (B) at 23 ° C. is usually 0.001 to 100 Pa · s, preferably 0.001 to 10 Pa · s.

As the component (B), for example, the following general formula (2):
R ³ ₂ HSiO (R ³ ₂ SiO) _n SiR ³ ₂ H (2)
(In the formula, R ³ is as described above, and n is such that the viscosity of the component (B) at 23 ° C. is usually 0.001 to 100 Pa · s, preferably 0.001 to 10 Pa · s. It is a large number.)
The linear organohydrogen polysiloxane represented by these is mentioned. As specific examples of the component (B), as long as the viscosity at 23 ° C. is 0.001 to 100 Pa · s, the molecular chain both ends dimethylhydrogensiloxy group blocked dimethylpolysiloxane, the molecular chain both ends diphenylhydrogensiloxy group blocked Dimethylpolysiloxane, dimethylhydrogensiloxy group-blocked methylphenylpolysiloxane at both ends of the molecular chain, dimethylhydrogensiloxy group-blocked diphenylpolysiloxane at both ends of the molecular chain, dimethylhydrogensiloxy group-blocked methylphenylsiloxane and dimethylsiloxane at both ends of the molecular chain Examples thereof include a polymer, a dimethylhydrogensiloxy group-blocked diphenylsiloxane / dimethylsiloxane copolymer having both molecular chain terminals, and a mixture of two or more of these.

[Component (C)]
Component (C) contains at least three hydrogen atoms bonded to a silicon atom, and R ³ HSiO unit and R ³ ₂ XSiO _1/2 unit [wherein R ³ is as described above, and X is a hydrogen atom Or represents R ³ . And / or an organohydrogenpolysiloxane having a viscosity at 23 ° C. of 0.001 to 100 Pa · s. (C) A component may be used individually by 1 type, or may be used in combination of 2 or more type.

  The component (C) is combined with the component (B) to form a curing agent for the adhesive of the present invention. The component (C) is essential for curing the adhesive of the present invention to form a three-dimensional crosslinked rubber, and greatly affects the adhesiveness of the adhesive of the present invention to silicone rubber.

  The molecular structure of the component (C) is not particularly limited, and examples thereof include a linear structure, a partially branched linear structure, a branched chain structure, a cyclic structure, a branched cyclic structure, and a three-dimensional network structure. . The component (C) may be a single polymer having these molecular structures, a copolymer having these molecular structures, or a mixture thereof. The SiH group in the component (C) may be present only in one of the molecular chain terminal part and the molecular chain non-terminal part, or may be present in both of them.

  The viscosity of component (C) at 23 ° C. is usually 0.001 to 100 Pa · s, preferably 0.001 to 10 Pa · s.

Examples of the component (C) include R ³ ₂ HSiO (R ³ HSiO) _p (R ³ ₂ SiO) _q SiR ³ ₂ H, R ³ ₃ SiO (R ³ HSiO) _r (R ³ ₂ SiO) _q SiR ³ ₃ , (R ³ ₂ HSiO) ₃ SiR ³ , (R ³ ₂ HSiO) ₄ Si, a copolymer comprising R ³ ₂ HSiO _1/2 units and SiO _4/2 units, R ³ ₂ HSiO _1/2 units And a copolymer comprising R ³ ₃ SiO _1/2 units and SiO _4/2 units [wherein R ³ is as described above, p is an integer of 1 or more, and q is an integer of 0 or more. And r is an integer of 3 or more, and each of p + q and r + q has a viscosity at 23 ° C. of the component (C) of usually 0.001 to 100 Pa · s, preferably 0.001 to 10 Pa · s. It is such a number. ]. Specific examples of the component (C) include (Me ₂ HSiO) ₃ SiMe, (Me ₂ HSiO) ₃ SiC ₆ H ₅ , Me ₂ HSiO (MeHSiO) _p SiMe ₂ H, Me ₂ HSiO (MeHSiO) _p (Me ₂ ). SiO) _q SiMe ₂ H, (Me ₂ HSiO) ₄ Si, Me ₃ SiO (MeHSiO) _p SiMe ₃ , Me ₃ SiO (MeHSiO) _p (Me ₂ SiO) _q SiMe ₃ , Me ₃ SiO (MeHSiO) ₄ (Me ₂ SiO) ₂ SiMe ₃ , Me ₃ SiO (MeHSiO) ₁₀ SiMe ₃ , a copolymer composed of Me ₂ HSiO _1/2 units and SiO _4/2 units, Me ₂ HSiO _1/2 units and (C ₆ H _{5 3} ) a copolymer composed of ₃ SiO _1/2 units and SiO _4/2 units, Me ₂ HSiO _1/2 unit And a copolymer of Me ₃ SiO _1/2 unit and SiO _4/2 unit, and a mixture of two or more thereof (wherein “Me” represents a methyl group).

  Here, the total amount of SiH groups in the components (B) and (C) is an alkenyl group bonded to silicon atoms in all adhesives (only the component (A) in all adhesives was bonded to silicon atoms). When it has an alkenyl group, it is usually 0.01 to 20 mol, preferably 0.1 to 10 mol, per mol of the alkenyl group bonded to the silicon atom in component (A). If the total amount is less than the lower limit of the range, the obtained adhesive tends to be hard to be cured sufficiently, and if the upper limit of the range is exceeded, the mechanical properties and heat resistance of the cured product of the obtained adhesive There is a tendency for the characteristics to easily deteriorate.

  The ratio of the amount of SiH groups in the component (C) to the total amount of SiH groups in the components (B) and (C) is usually 5 to 98 mol%, preferably 10 to 95 mol. %. When the ratio is less than the lower limit of the range, the obtained adhesive tends to be hard to be cured sufficiently. When the ratio exceeds the upper limit of the range, the elongation property of the cured product of the obtained adhesive is likely to be lowered. As a result, the heat resistance tends to decrease.

[Component (D)]
The component (D) is finely divided silica having a specific surface area of 50 m ² / g or more (usually 50 to 400 m ² / g), preferably 100 to 350 m ² / g. The specific surface area can be measured, for example, by a nitrogen gas adsorption method, particularly a BET method. (D) component is mix | blended in order to provide intensity | strength to the adhesive agent obtained. (D) A component may be used individually by 1 type, or may be used in combination of 2 or more type.

  As the component (D), known fine powder silica can be used. The component (D) may be hydrophilic fine powder silica or hydrophobic fine powder silica. Examples of the hydrophilic fine powder silica include wet silica such as precipitated silica, and dry silica such as silica xerogel and fumed silica. Examples of the hydrophobic fine powder silica include fine powder silica obtained by hydrophobizing the surface of hydrophilic fine powder silica. Examples of the hydrophobizing agent include organosilazanes such as hexamethyldisilazane; halogenated silanes such as methyltrichlorosilane, dimethyldichlorosilane, and trimethylchlorosilane; alkoxy having halogen atoms of the halogenated silane such as methoxy group and ethoxy group. And organoalkoxysilane substituted with a group. Examples of the hydrophobic treatment method include a method in which hydrophilic fine powder silica is heated with a hydrophobizing agent at 150 to 200 ° C., particularly 150 to 180 ° C. for about 2 to 4 hours. Hydrophobic fine powder silica obtained by previously hydrophobizing the surface of the hydrophilic fine powder silica in this way may be added to the adhesive of the present invention. The surface of the hydrophilic fine powder silica may be hydrophobized in the step of preparing the adhesive of the present invention by blending a hydrophobizing agent with the fine powder silica.

  Specific examples of the component (D) include Aerosil (registered trademark) 50, 130, 200 and 300 (trade names, manufactured by Nippon Aerosil Co., Ltd.), Cabocil (registered trademark) MS-5 and MS-7 (trade names, Cabot Corporation). ), Leorosil QS-102 and 103 (trade name, manufactured by Tokuyama Co., Ltd.), Nipsil LP (trade name, manufactured by Nippon Silica Co., Ltd.), and the like; Aerosil (registered trademark) R-812, R-812S , R-972 and R-974 (trade name, manufactured by Degussa), Leorosil MT-10 (trade name, manufactured by Tokuyama), Nipsil SS series (trade name, manufactured by Nippon Silica), etc. Is mentioned.

  (D) The compounding quantity of a component is 1-100 mass parts normally with respect to 100 mass parts of said (A) component. If the blending amount is less than 1 part by mass, the effect of imparting strength due to the component (D) tends to be insufficient, and if it exceeds 100 parts by mass, the resulting adhesive tends to be extremely lacking in fluidity and workability is improved. It tends to be inferior.

[(E) component]
Component (E) is a platinum group metal catalyst, and any known hydrosilylation reaction catalyst can be used. (E) A component may be used individually by 1 type, or may be used in combination of 2 or more type. Examples of the component (E) include platinum group metals such as platinum (including platinum black), rhodium and palladium; H ₂ PtCl ₄ · nH ₂ O, H ₂ PtCl ₆ · nH ₂ O, NaHPtCl ₆ · nH _2. O, KHPtCl ₆ · nH ₂ O, Na ₂ PtCl ₆ · nH ₂ O, K ₂ PtCl ₄ · nH ₂ O, PtCl ₄ · nH ₂ O, PtCl ₂ , Na ₂ HPtCl ₄ · nH ₂ O (where n Is an integer from 0 to 6, preferably 0 or 6.) Alcohol-modified chloroplatinic acid (see US Pat. No. 3,220,972) ); Complex of chloroplatinic acid and olefin (see US Pat. Nos. 3,159,601, 3,159,662, and 3,775,452); platinum black, Platinum group metals such as palladium Supported on a carrier such as carbon and carbon; complex of platinum and triphenylphosphine; rhodium-olefin complex; chlorotris (triphenylphosphine) rhodium (Wilkinson catalyst); platinum chloride, chloroplatinic acid or chloroplatinic acid And a complex of a salt and a vinyl group-containing siloxane, particularly a vinyl group-containing cyclic siloxane. Among these, platinum black; chloroplatinic acid; a complex of chloroplatinic acid and an olefin; a complex of platinum chloride, chloroplatinic acid or chloroplatinate and a vinyl group-containing siloxane, particularly a vinyl group-containing cyclic siloxane; A platinum-based catalyst such as a complex with triphenylphosphine is desirable.

  The amount of component (E) may be an effective amount as a hydrosilylation reaction catalyst, and is not particularly limited as long as a desired curing rate can be obtained. As the blending amount, for example, the amount of the platinum group metal in the component (E) with respect to the total amount of the adhesive of the present invention is usually 0.1 to 1,000 ppm, preferably 0.1 to 1000 ppm on a mass basis. The amount is 500 ppm, particularly preferably 0.5 to 200 ppm.

[(F) component]
The component (F) is an organic titanium compound and is an optional component of the adhesive of the present invention. The component (F) can be used as a catalyst for further promoting the curing of the adhesive of the present invention and further improving the adhesion. (F) A component may be used individually by 1 type, or may be used in combination of 2 or more type.

  Examples of the component (F) include a titanium chelate compound, alkoxy titanium, or a combination thereof. Specific examples of the titanium chelate compound include diisopropoxybis (acetylacetonato) titanium, diisopropoxybis (ethylacetoacetate) titanium, dibutoxybis (methylacetoacetate) titanium and the like. Specific examples of alkoxy titanium include tetraethyl titanate, tetrapropyl titanate, tetrabutyl titanate and the like. The alkoxy group in alkoxy titanium may be linear or branched.

  The amount of component (F) is usually 10 parts by mass or less (0 to 10 parts by mass, for example, 0.01 to 10 parts by mass, preferably 0 to 100 parts by mass of component (A). When the blending amount is less than the lower limit of the range, the effect of improving the adhesiveness due to the component (F) may be difficult to appear, and when the amount exceeds the upper limit of the range, it is obtained. The surface hardening of the resulting adhesive may be too fast.

[(G) component]
The component (G) is a filler other than the component (D) and is an optional component of the adhesive of the present invention. (G) A component may be used individually by 1 type, or may be used in combination of 2 or more type.

  The component (G) is not particularly limited as long as the object of the present invention is not impaired. For example, inorganic pigments such as cobalt blue, colorants such as organic dyes; diatomaceous earth, potassium oxide, zinc oxide, iron oxide, oxidation Heat resistance and flame retardancy improvers such as titanium, aluminum oxide, copper oxide, calcium carbonate, zinc carbonate, manganese carbonate, bengara, carbon black, pulverized quartz powder, aluminum hydroxide, copper, silver, gold, nickel; Examples thereof include fillers obtained by treating the surface of the filler with an organosilicon compound such as organoalkoxysilane, organohalosilane, or organosilazane.

  When (G) component is mix | blended with this invention adhesive, the compounding quantity normally exceeds 0 mass part with respect to 100 mass parts of (A) component, and is 100 mass parts or less, Preferably it is 0.1-100 mass. Parts, more preferably in the range of 1-50 parts by weight.

[(H) component]
Component (H) is an organopolysiloxane resin having a three-dimensional network structure and is an optional component of the adhesive of the present invention. (H) A component may be used individually by 1 type, or may be used in combination of 2 or more type.

Component (H) is not particularly limited, but is the above resin containing an alkenyl group bonded to a silicon atom, particularly a vinyl group bonded to a silicon atom, because the strength of the cured product of the resulting adhesive is higher. It is preferable. As the component (H), for example, a monofunctional siloxane unit represented by a formula: (CH ₃ ) ₃ SiO _1/2 or the like: R ⁴ ₃ SiO _1/2 or the like (R ⁴ is independently an aliphatic group Represents an unsubstituted or substituted monovalent hydrocarbon group not containing a saturated bond) and an organopolysiloxane resin (resin 1) containing a siloxane unit represented by SiO _4/2 or the like, an alkenyl bonded to a silicon atom A siloxane unit containing a group and a SiO _4/2 unit and a R ⁴ SiO _3/2 unit (R ⁴ independently represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond). either or organopolysiloxane resin containing a both (resin 2), in addition to the siloxane units in the resin 2, further ^R ₄ 3 _{SiO 1/2} units ^{(R 4} are as described above.) Organopolysiloxane resin (Resin 3), and the like containing, resin 2 and 3 are particularly preferred.

Examples of the siloxane unit containing an alkenyl group bonded to a silicon atom include a siloxane unit represented by the formula: R ⁵ SiO _3/2 , a siloxane unit represented by the formula: R ⁵ R ⁶ SiO _2/2 , A siloxane unit represented by the formula: R ⁵ R ⁶ ₂ SiO _1/2 (wherein R ⁵ independently represents an alkenyl group such as a vinyl group, and R ⁶ independently represents an aliphatic group such as a methyl group or a phenyl group) Monofunctional, difunctional or trifunctional siloxane units such as an unsubstituted or substituted monovalent hydrocarbon group not containing an unsaturated bond.

As said R < ⁴ >, the C1-C10 unsubstituted or substituted monovalent hydrocarbon group which does not contain an aliphatic unsaturated bond is mentioned, for example. Specific examples of R ⁴ include monovalent hydrocarbon groups specifically exemplified for R ¹ in the above average composition formula (1), and among them, a methyl group and a phenyl group are particularly preferable.

Examples of R ⁵ include alkenyl groups having 2 to 8 carbon atoms. Specific examples of R ⁵ include alkenyl groups specifically exemplified for R ² in the above average composition formula (1), and among them, vinyl groups are preferable.

As said R < ⁶ >, the C1-C10 unsubstituted or substituted monovalent hydrocarbon group which does not contain an aliphatic unsaturated bond is mentioned, for example. Specific examples of R ⁶ include monovalent hydrocarbon groups specifically exemplified for R ¹ in the above average composition formula (1), and among them, a methyl group and a phenyl group are particularly preferable.

  When the component (H) contains an alkenyl group bonded to a silicon atom, the content of the alkenyl group in the component (H) is 1 to 5% by mass of the total organic groups bonded to the silicon atom. Preferably, it is especially preferable that it is 2-3 mass%. When the content is within this range, the risk of forming and mixing resin molecules not containing an alkenyl group bonded to a silicon atom in the component (H) can be reduced. It is easy to maintain high elongation and heat resistance.

Specific examples of the component (H) include a resin containing (CH ₃ ) ₃ SiO _1/2 units and SiO _4/2 units, (CH ₃ ) ₃ SiO _1/2 units and (CH ₂ = CH) SiO. Resin containing _3/2 units and SiO _4/2 units, Resin containing (CH ₂ ═CH) (CH ₃ ) ₂ SiO _1/2 units and SiO _4/2 units, (CH ₂ ═CH) Resin containing (CH ₃ ) ₂ SiO _1/2 unit, (CH ₂ = CH) SiO _3/2 unit and SiO _4/2 unit, (CH ₂ = CH) (CH ₃ ) ₂ SiO _1/2 unit And a resin containing (CH ₃ ) ₃ SiO _1/2 unit and SiO _4/2 unit, (CH ₂ ═CH) SiO _3/2 unit, (CH ₃ ) ₃ SiO _1/2 unit and SiO _4/2 And a resin containing a unit.

  When (H) component is mix | blended with this invention adhesive, the compounding quantity normally exceeds 0 mass part with respect to 100 mass parts of (A) component, and is 100 mass parts or less, Preferably it is 0.1-100 mass. Parts, more preferably in the range of 1-50 parts by weight.

[Other ingredients]
In addition to the components (A) to (H) described above, other components can be blended in the adhesive of the present invention as necessary.

  The adhesive of the present invention may contain a curing control agent in order to improve its storage stability or to improve its handling workability by adjusting its curing time or pot life. . Examples of the curing control agent include acetylene-based compounds such as 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and 3-phenyl-1-butyn-3-ol. Compound; Enyne compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexen-1-yne; 1,3,5,7-tetramethyl-1,3,5,7 -Tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane, silanol group-blocked methylvinylsiloxane (), silanol with both ends of molecular chain Organosiloxane compounds having 5% by mass or more of vinyl groups in one molecule, such as blocked methylvinylsiloxane / dimethylsiloxane copolymer; Triazoles such as benzotriazole; Phosphine ; Mercaptans; hydrazines and the like. These curing control agents may be used alone or in combination of two or more. When mix | blending this hardening control agent with this invention adhesives, the compounding quantity is not specifically limited, Usually, 0.001-5 mass parts with respect to 100 mass parts of (A) component, Preferably 0.01- It is in the range of 5 parts by mass.

  You may mix | blend an adhesion | attachment imparting agent with this invention adhesives in order to improve the adhesiveness. Examples of the adhesion-imparting agent include methyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-aminopropyltrimethoxysilane. Silane coupling agents such as N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, bis (trimethoxysilyl) propane, bis (trimethoxysilyl) hexane; tetraethyl titanate, tetrapropyl titanate, tetrabutyl titanate , Titanium compounds such as tetra (2-ethylhexyl) titanate, titanium ethyl acetonate, titanium acetyl acetonate; alkyl acetoaceto aluminum aluminium such as ethyl acetoaceto aluminum diisopropylate Aluminum compounds such as diisopropylate, aluminum tris (ethyl acetoacetate), aluminum tris (acetylacetonate), aluminum monoacetylacetonate bis (ethylacetoacetate); zirconium acetylacetonate, zirconium butoxyacetylacetonate, zirconium bisacetyl Zirconium compounds such as acetonate and zirconium ethyl acetoacetate are listed. These adhesion-imparting agents may be used alone or in combination of two or more. When the adhesion-imparting agent is blended with the adhesive of the present invention, the blending amount is not particularly limited, but is preferably in the range of 0.01 to 10 parts by mass with respect to 100 parts by mass of component (A).

[Production method of adhesive]
The method for preparing the adhesive of the present invention is not limited, and it can be prepared by simultaneously mixing the components (A) to (E) and, if necessary, the components (F) to (H) and other components. In addition, (A) component and (D) component are heated and mixed in advance to prepare a base compound, and (B) component, (C) component and (E) component, and, if necessary, ( Components F) to (H) may be added. Furthermore, when preparing this base compound, the surface of the component (D) may be hydrophobized by blending the hydrophobizing agent in addition to the components (A) and (D). In addition, when mix | blending other components with this invention adhesive agent, when preparing a base compound, this other component may be mix | blended with (A) and (D) component, and it is in the obtained base compound. You may add with (B) component, (C) component, (E) component, and (F)-(H) component as needed. When the other components are altered by heating and mixing, the other components are preferably blended into the adhesive of the present invention by the latter method. When preparing the adhesive of the present invention, a known kneading apparatus such as a two-roll mill, a three-roll mill, a kneader mixer, or a planetary mixer can be used.

[Use of adhesive]
The adhesive of the present invention can be cured after being applied to an addition reaction curable silicone rubber. The curing conditions of the adhesive of the present invention may be the same as the curing conditions of a known addition reaction curable silicone rubber composition. The adhesive of the present invention is sufficiently cured, for example, at room temperature, and exhibits adhesiveness to the addition reaction curable silicone rubber, but may be cured by heating to about 60 to 180 ° C. as necessary. The adhesive of the present invention can be used as an adhesive having an addition reaction curable silicone rubber as an adherend.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated in detail, this invention is not restrict | limited to these Examples. In the following examples, “Me” represents a methyl group, and the viscosity is a value at 23 ° C.

[Example 1]
(A) 100 parts by mass of dimethylpolysiloxane blocked with dimethylvinylsiloxy group at both ends of a molecular chain having a viscosity of 30 Pa · s, (d) 15 parts by mass of fumed silica having a specific surface area measured by the BET method of 300 m ² / g, silica As a hydrophobizing agent for the surface, 1.5 parts by mass of hexamethyldisilazane and 1 part by mass of water were uniformly mixed, and then heated and mixed at 160 ° C. for 4 hours under reduced pressure to prepare a base compound. Next, 115 parts by mass of this base compound is added to (b) silicon atoms in the component (a) component (a) contained in the base compound, the dimethylhydrogensiloxy group-blocked dimethylpolysiloxane having a viscosity of 0.01 Pa · s. (C) (Me ₂ HSiO) ₃ SiMe, expressed in terms of the molar ratio of the silicon atom-bonded hydrogen atoms (ie, SiH groups) in the component (b) to the bonded vinyl group being 0.1), 3 Organohydrogenpolysiloxane having a number of silicon-bonded hydrogen atoms and a viscosity of 0.0012 Pa · s (the silicon atom in the component (c) relative to the vinyl group in the component (a) contained in the base compound) A molar ratio of bonded hydrogen atoms to 1.4), and a silanol group-blocked dimethyl silo having a viscosity of 40 mPa · s as a curing inhibitor. Xanthine-methylvinylsiloxane copolymer (vinyl group content = 8% by mass) 0.2 parts by mass, (f) tetrabutyltitanate 0.3 parts by mass, and (e) platinum 1,3-divinyltetramethyl For silicone rubber by mixing with disiloxane complex (amount of platinum metal in component (e) is 25 parts by mass with respect to 1 million parts by mass of dimethylpolysiloxane as component (a) in the base compound) An adhesive was prepared.

-Hardness The said adhesive agent was hardened by leaving to stand at 23 degreeC for 1 day (24 hours). The hardness of the cured adhesive was measured with a type A durometer specified in JIS K 6253. The measurement results are shown in Table 1.

Elongation and Tensile Strength The above adhesive was cured by leaving it at 23 ° C. for 1 day (24 hours) to prepare a dumbbell-shaped No. 3 test piece defined in JIS K 6251. The elongation and tensile strength of this test piece were measured by the method specified in JIS K 6251. The measurement results are shown in Table 1.

-Adhesive force and failure mode The adhesive force of the above-mentioned adhesive to the addition-curable silicone rubber was measured in the following manner according to the method specified in JIS K 6854. A 25 mm wide silicone rubber-coated nylon tape coated with a cured product (silicone rubber) of an addition reaction curable silicone rubber composition is bonded to each other so that the thickness of the adhesive is 0.6 mm, and then at 23 ° C. for 1 day. The adhesive was cured by allowing it to stand. Next, a T-type peel test was performed on the bonded tape at a tensile speed of 300 mm / min, and the adhesive strength was measured. The measurement results are shown in Table 1.

  Moreover, the fracture mode was confirmed by visually observing the state of the interface between the cured adhesive and the tape after peeling. In the case where the cured adhesive product has undergone cohesive failure, Table 1 indicates “cohesive failure”. When the silicone rubber coated on the tape is broken, it is indicated as “silicone rubber broken” in Table 1.

-Storage stability In order to evaluate storage stability, the composition which consists of a component remove | excluding only the hardening | curing agent component, ie, (b) and (c) component, was first prepared from the said adhesive agent. This composition was allowed to stand at 70 ° C. for 1 week, and then the curing agent component was mixed to prepare an adhesive. The adhesive was cured to obtain a cured product, and the physical properties (hardness, elongation, tensile strength, adhesive force) of the cured product were measured in the same manner as described above, and the fracture mode was observed. At this time, it was confirmed whether or not a curing delay occurred as compared with the adhesive before leaving. Moreover, it was confirmed whether the said physical property fell before and after leaving. Furthermore, it was confirmed whether or not the destruction mode changes before and after being left. Specifically, when the curing time of the adhesive after being left was twice or more than the curing time of the adhesive before being left, it was evaluated that a curing delay occurred in the adhesive after being left. In addition, regarding each physical property, when the value of the cured product of the adhesive after being left was 70% or less of the value of the cured product of the adhesive before being left, it was evaluated that the physical property was lowered before and after being left. When the curing delay did not occur, the above physical properties did not decrease, and the fracture mode did not change, it was evaluated that the storage stability was good, and “◯” was displayed in Table 1. In other cases, the storage stability was evaluated as poor.

[Example 2]
In Example 1, the molar ratio of the silicon atom-bonded hydrogen atom in the component (b) to the vinyl group bonded to the silicon atom in the component (a) contained in the base compound is 0. The amount of the component (c) is changed to the amount of 7 and the molar ratio of the silicon atom hydrogen atom in the component (c) to the vinyl group bonded to the silicon atom in the component (a) contained in the base compound is An adhesive for silicone rubber was prepared in the same manner as in Example 1 except that the amount was changed to 0.8. The adhesive was measured in the same manner as in Example 1. The measurement results are shown in Table 1.

[Example 3]
In Example 1, the molar ratio of the silicon atom-bonded hydrogen atom in the component (b) to the vinyl group bonded to the silicon atom in the component (a) contained in the base compound is 1. The amount of the component (c) is changed to the amount to be 2, and the molar ratio of the silicon atom hydrogen atom in the component (c) to the vinyl group bonded to the silicon atom in the component (a) contained in the base compound is An adhesive for silicone rubber was prepared in the same manner as in Example 1 except that the amount was changed to 0.3. The adhesive was measured in the same manner as in Example 1. The measurement results are shown in Table 1.

[Comparative Example 1]
In Example 1, without using the component (b), the amount of the component (c) is changed to the amount of silicon atom hydrogen in the component (c) relative to the vinyl group bonded to the silicon atom in the component (a) contained in the base compound. A silicone rubber adhesive was prepared in the same manner as in Example 1 except that the molar ratio of the atoms was changed to 1.5. The adhesive was measured in the same manner as in Example 1. The measurement results are shown in Table 1.

[Comparative Example 2]
In Example 1, the molar ratio of the silicon atom-bonded hydrogen atom in the component (b) to the vinyl group bonded to the silicon atom in the component (a) contained in the base compound is 1. The silicone rubber adhesive was prepared in the same manner as in Example 1 except that the amount was changed to 5 and the component (c) was not used. This adhesive was not cured and the same measurement as in Example 1 could not be performed. This result is shown as “Uncured” in Table 1.

Claims (6)

(A) 100 parts by mass of an organopolysiloxane containing at least two alkenyl groups bonded to silicon atoms and having a viscosity at 23 ° C. of 0.05 to 1,000 Pa · s,
(B) R ³ ₂ HSiO _1/2 units having hydrogen atoms bonded to silicon atoms only at both ends of the molecular chain [wherein R ³ is independently an unsubstituted or substituted monovalent group that does not contain an aliphatic unsaturated bond. Represents a hydrocarbon group. And a linear organohydrogenpolysiloxane having a viscosity at 23 ° C. of 0.001 to 100 Pa · s,
(C) containing at least three hydrogen atoms bonded to a silicon atom, an R ³ HSiO unit and an R ³ ₂ XSiO _1/2 unit [wherein R ³ is as described above, and X is a hydrogen atom or R ³ Represents. Any one of both, and an organohydrogenpolysiloxane having a viscosity at 23 ° C. of 0.001 to 100 Pa · s,
(D) 1 to 100 parts by mass of finely divided silica having a specific surface area of 50 m ² / g or more ,
(E) an effective amount of a platinum group metal catalyst, and
(F) 0.01 to 10 parts by mass of an organic titanium compound ,
The total amount of hydrogen atoms bonded to silicon atoms in the components (B) and (C) is 0.01 to 20 mol per mol of alkenyl groups bonded to silicon atoms in all adhesives, and B) and addition reaction curable type wherein the ratio of the amount of hydrogen atoms bonded to silicon atoms in component (C) to the total amount of hydrogen atoms bonded to silicon atoms in component (C) is 5-98 mol% Silicone rubber adhesive. The adhesive according to claim 1, which is used for adhesion to an addition reaction curable silicone rubber. (G) Filler other than component (D) The adhesive according to claim 1 or 2, further comprising more than 0 parts by mass and 100 parts by mass or less. (H) Organopolysiloxane resin having a three-dimensional network structure The adhesive according to any one of claims 1 to 3, further comprising 0 part by mass and 50 parts by mass or less. The component (H) includes a siloxane unit containing an alkenyl group bonded to a silicon atom, a SiO _4/2 unit, and an R ⁴ SiO _3/2 unit (R ⁴ independently contains a non-aliphatic unsaturated bond). The adhesive according to claim 4, which is an organopolysiloxane resin containing one or both of a substituted or substituted monovalent hydrocarbon group. The adhesive according to claim 5, wherein the component (H) is an organopolysiloxane resin further containing R ⁴ ₃ SiO _1/2 units (R ⁴ is as described above).