JPH1112544A - Primer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition useful for bonding a rubber for vulcanization with a peroxide to various substrates by including a specific organosilicon compound therein. SOLUTION: This composition is obtained by compounding (A) an organosilicon compound represented by formulae I and/or II one or two of R<1> to R<3> and R<7> to R<9> are each a silylalkyl represented by formula III [R<4> and R<5> are each a (un)substituted monovalent hydrocarbon; R<6> is an alkylene; (n) is 1-3] and the remaining groups are each a monovalent organic group having an unsaturated bond} in an amount of 5-100 wt.% based on the solid content except a solvent (e.g. N,N'-diallyl-N"-3-trimethoxysilylpropyl isocyanurate), as necessary, with (B) another organosilicon compound having a hydrolyzable group in an amount of <=95 wt.% based on the solid content except the solvent and, as necessary, adding (C) titanates, a pigment, a metallic powder, etc., thereto. The composition is dissolved or dispersed in a solvent for use.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primer composition, and more particularly to a primer composition useful for bonding a rubber for peroxide vulcanization to various substrates.

[0002]

2. Description of the Related Art In bonding peroxide-cured rubber such as fluororubber to various substrates, a primer mainly comprising a silane coupling agent is often used because of its excellent heat resistance and workability. . At this time, a silane coupling agent having a vinyl group or an allyl group suitable for a peroxide vulcanization reaction is generally used. However, in the case of a rubber which is not easily bonded, such as a fluororubber, the conventional primer showed variations in the adhesive strength due to molding conditions and the like.

[0003]

An object of the present invention is to provide a primer composition containing an organosilicon compound suitable for peroxide vulcanization.

[0004]

The present invention is a primer composition containing an organosilicon compound represented by the formula 1 or 2.

[0005]

Embedded image

In Formula 1, one or two of R ¹ , R ² , and R ³ are silylalkyl groups represented by Formula 3, and the rest are monovalent organic groups having an unsaturated bond. In Formula 2, one or two of R ⁷ , R ⁸ , and R ⁹ are silylalkyl groups represented by Formula 3, and the rest are monovalent organic groups having an unsaturated bond. In the formula 3, R ⁶ is an alkylene group, R ⁴ is a substituted or unsubstituted monovalent hydrocarbon group,
⁵ is a substituted or unsubstituted monovalent hydrocarbon group;
Is an integer.

The organosilicon compound contained in the primer composition of the present invention acts as a silane coupling agent and has at least one organic group having an unsaturated bond and at least one silylalkyl group in one molecule. In particular, by having the same structure as triallyl isocyanurate or triallyl cyanurate which is preferably used as a crosslinking aid for rubber for peroxide vulcanization, co-crosslinks with the rubber during vulcanization,
It is thought to provide stable and strong adhesion between rubber and various substrates.

The organosilicon compound used in the present invention is
It is represented by Equation 1 or Equation 2. R ⁷ of one or two R ^1, R ^2, R ³ of Formula 1, and Formula 2, R ^8, 1 of R ⁹
Or 2 is a silylalkyl group represented by the formula 3,
The rest is a monovalent organic group having an unsaturated bond.

Preferred examples of the monovalent organic group having an unsaturated bond include an alkenyl group, and examples of the alkenyl group include a vinyl group, a propenyl group and a butenyl group.

In the silylalkyl group represented by the formula 3, R ⁶ is an alkylene group, and preferably includes, for example, an ethylene group and a propylene group. R ⁵ is preferably a methyl group, a propyl group or a butyl group.
R ⁴ is preferably a monovalent hydrocarbon group having an unsaturated bond or a monovalent hydrocarbon group having no unsaturated bond.

As the monovalent hydrocarbon group having an unsaturated bond, for example, a vinyl group, a propenyl group, a butenyl group and the like are preferable. Further, examples of the monovalent hydrocarbon group having no unsaturated bond include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and the like, preferably an aliphatic hydrocarbon group, Particularly preferred is an alkyl group.

Examples of the alkyl group include a methyl group,
Lower alkyl groups such as an ethyl group and a propyl group are preferred. N in the formula 3 is an integer of 1 to 3, preferably 2 or 3.

The two types of organosilicon compounds of the above formulas 1 and 2 may be used alone or in combination.

The method for producing the organosilicon compound in the present invention is not limited. For example, it is synthesized by reacting diallyl isocyanurate sodium salt with 3-chloropropyltrimethoxysilane using dimethylacetamide as a solvent. Kaihei 5-39294). As the organosilicon compound, a reaction mixture of one in which three silyl groups are not introduced in one molecule but also one in which three silyl groups are introduced can be used, and the number of silyl groups introduced into the mixture is an average of 0.2 to 0.2 per molecule. About 2.8 is preferable.

As the organosilicon compound, specifically,
N, N'-diallyl-N "-3-trimethoxysilylpropyl isocyanurate, N-allyl-N ', N" -bis (3-trimethoxysilylpropyl) isocyanurate, N, N'-dimethallyl-N " -3-triethoxysilylpropyl isocyanurate, N-methallyl-N ',
N "-bis (3-methyldimethoxysilylpropyl) isocyanurate, O, O'-diallyl-O" -3-trimethoxysilylpropyl cyanurate, O-allyl-
O ', O "-bis (3-trimethoxysilylpropyl)
Cyanurate, O, O'-Dimethallyl-O "-3-triethoxysilylpropyl cyanurate, O-methallyl-
O ′, O ″ -bis (3-methyldimethoxysilylpropyl) cyanurate and the like are used, and these are used alone or as a mixture of two or more.

The organosilicon compound used in the present invention is
It is also possible to partially hydrolyze beforehand to increase the molecular weight before use. In addition, different functional groups can be introduced into the molecule by partial co-hydrolysis with another organosilicon compound having a hydrolyzable group.

The primer composition of the present invention is prepared by adding these organosilicon compounds to a solid material excluding a solvent in an amount of 5 to 100%.
It is preferable to include it in a ratio of weight%. If this ratio is too small, it is difficult to obtain the desired effect.

Other organosilicon compounds having a hydrolyzable group include γ-aminopropyltrimethoxysilane,
γ- (2-aminoethyl) aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxy Silane,
Allyl trimethoxy silane, methyl triethoxy silane, methyl trichloro silane, trimethoxy silane, triethoxy silane, trichloro silane, diethoxy silane, tetramethoxy silane, tetra ethoxy silane, etc., and these may be used alone or in combination of two or more. Are used in combination.

These may be used after partial hydrolysis or partial cohydrolysis. Further, it may be used after being co-hydrolyzed with another organosilicon compound having a hydrolyzable group.

The primer composition of the present invention contains 95% by weight of these organosilicon compounds with respect to the solids excluding the solvent.
It is preferable to include the following proportions. If this ratio is too large, it is difficult to obtain the desired effect.

Any component can be added to the primer composition of the present invention as long as its performance is not impaired. Examples of such components include titanates such as tetrabutyl titanate and diisopropoxytitanium acetylacetonate, aluminum alkoxides such as aluminum acetylacetonate and aluminum tributoxide, dibutyltin diacetate, dibutyltin dioctanoate and organic compounds such as dibutyltin dilaurate. Peroxides such as tin compounds, dicumyl peroxide, 2,5-dimethyl-2,5-di-t-butylperoxyhexane, unsaturated polyfunctional compounds such as triallyl isocyanurate and trimethallyl isocyanurate, pigments And metal oxides and hydroxides, metal powders, organic polymer materials such as silicone and epoxy resins, and the like, and the type and amount thereof are appropriately selected according to the application.

The primer composition of the present invention is used after being dissolved or dispersed in a solvent. The type and amount of the solvent are not limited, and are appropriately selected depending on the application, working conditions, and the like. Examples of the solvent include alcohols such as methanol and ethanol, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and butyl acetate, aliphatic or aromatic hydrocarbons such as hexane, octane, toluene, and xylene, and hydrochlorofluorocarbons. , Fluorocarbons and the like.

The primer composition of the present invention is applied to various substrates such as metal, glass, ceramics, cement, stone, thermoplastic resin, thermosetting resin, and rubber, and unvulcanized rubber is coated thereon. By overlapping and vulcanizing the rubber, the rubber and the base material adhere to each other. It is preferable to dry the primer after application. The drying conditions are not limited, but are preferably in the range of room temperature to about 200 ° C. for several minutes to several days.

The primer composition of the present invention can be added to rubber or resin to give them adhesion. It can also be used as a surface treatment agent for various substrates.

[0025]

EXAMPLES Next, reference examples (Examples 1 to 3) and examples (Examples 4 to 4)
6), the present invention will be described in detail with reference to Comparative Examples (Examples 7 and 8). In addition, the part in an example shows a weight part.

Example 1 Fluorine rubber (Afras 150P,
100 parts of Asahi Glass), 30 parts of MT carbon, 3 parts of triallyl isocyanurate, perbutyl P (peroxide,
One part of Nippon Yushi Co., Ltd.) was uniformly kneaded with two rolls to obtain a peroxide-vulcanized fluororubber composition (rubber-1).

[Example 2] Fluorine rubber (Daiel G902,
100 parts of Daikin Industries, 30 parts of MT carbon, 3 parts of triallyl isocyanurate, 1 part of perhexa 2,5B (peroxide, manufactured by NOF Corporation) are uniformly kneaded with 2 rolls, and peroxide-vulcanized fluororubber composition (rubber) -2) was obtained.

Example 3 100 parts of a fluorosilicone rubber compound (FE251U, manufactured by Shin-Etsu Chemical Co., Ltd.), peroxide masterbatch (C-8, manufactured by Shin-Etsu Chemical Co., Ltd.) 1
The parts were uniformly kneaded with two rolls to obtain a peroxide-vulcanized fluorosilicone rubber composition (rubber-3).

[Examples 4 to 8] A primer composition having the composition shown in Table 1 was prepared, applied to the base material shown in Table 1, and the rubber obtained in Reference Example was overlaid and pressed at 170 ° C. for 10 minutes. Vulcanization was performed, and the adhesion state of the obtained vulcanized product was examined. The bonding state was represented by the cohesive failure area ratio (%) of rubber at the bonding interface. Table 1 shows the conditions for drying the primer, the conditions for vulcanizing the rubber, and the state of adhesion.

The components of the primer composition shown in Table 1 are described as follows. Silane-1: N, N'-diallyl-N "-3-trimethoxysilylpropyl isocyanurate, Silane-2: N-allyl-N ', N" -bis (3-trimethoxysilyl) isocyanurate, Silane- 3: vinyltrimethoxysilane, silane-4: γ-aminopropyltriethoxysilane, silane-5: tetraethoxysilane, TBT: tetrabutyl titanate.

[0031]

[Table 1]

[0032]

The primer composition of the present invention co-crosslinks with the rubber during the vulcanization of the rubber to provide a stable and strong adhesion between the rubber and various substrates.

Continued on front page (72) Inventor Yoshihiro Takayama 34 Takayama, Onahama, Iwaki-shi, Fukushima Japan Chemical Co., Ltd.

Claims (1)

[Claims] 1. A primer composition containing an organosilicon compound represented by the formula 1 or 2. Embedded image (In Formula 1, one or two of R ¹ , R ² , and R ³ are silylalkyl groups represented by Formula 3, and the rest are monovalent organic groups having an unsaturated bond. , R
One or two of ⁷ , R ⁸ and R ⁹ are silylalkyl groups represented by the formula 3, and the rest are monovalent organic groups having an unsaturated bond. In the formula 3, R ⁶ is an alkylene group, R
⁴ is a substituted or unsubstituted monovalent hydrocarbon group, R ⁵ is a substituted or unsubstituted monovalent hydrocarbon group, and n is an integer of 1 to 3. )