JPH04366172A - Primer composition - Google Patents

Abstract

PURPOSE:To obtain a primer composition which can improve the adhesion of a silicone rubber to a metallic surface by using a specified amino-containing organosilicon compound (its partial hydrolysis product) as the principal component. CONSTITUTION:An amino-containing organosilicon compound of the formula [wherein R<1> are H or (un)substituted monovalent hydrocarbon groups and at least one of them is an unsaturated group; R<2> and R<3> are each H or an (un) substituted monovalent hydrocarbon group; and n is 1-3] and optionally a condensation catalyst are diluted with an organic solvent.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a primer composition, particularly a primer composition which is made of an amino group-containing organosilicon compound as a main ingredient and is useful for firmly adhering silicone rubber to metal surfaces, etc. It is about things.

0002

2. Description of the Related Art Silicone rubber has excellent physical and chemical properties and is widely used in various applications, but it is also used as a composite with metals, plastics, etc. However, silicone rubber has poor adhesion to metals and plastics for this composite, and in order to manufacture this composite, vinyltrimethoxysilane or vinyltri(2-methoxyethoxy)silane is applied to the metal, plastic, etc. surface in advance. , a primer composition comprising an alkoxysilane having an unsaturated bond such as 3-methacryloxypropyltrimethoxysilane, a hydrolyzed condensate thereof, or a cohydrolyzed siloxane, a titanate ester, or a metal salt of an organic fatty acid. The method used is to apply silicone rubber and then adhere it to a cured silicone rubber product, but even with this method, the adhesive surface cannot maintain adhesion for a long time at high temperatures of, for example, 200°C or higher. , and also has the disadvantage of causing a peeling phenomenon in high-temperature oil.

0003

[Problems to be Solved by the Invention] Therefore, for this type of primer composition, vinyl group-containing organopolysiloxane, polysiloxane resin, alkoxysilane,
A rubber paste-like product consisting of an organic peroxide and a catalyst has also been proposed (see Japanese Patent Publication No. 39817/1983).
This improves adhesion at high temperatures and in high-temperature oil, but this has the disadvantage that the composition is complex and requires a lot of labor and time to manufacture, and the rubber injected during injection molding. It has the drawback that part or all of the primer layer may peel off due to the flow of the compound, and furthermore, it has poor air drying properties and requires a certain amount of heat treatment to prevent the primer layer from flowing, which is a hassle in processing. There were some disadvantages as well.

0004

[Means for Solving the Problems] The present invention relates to a primer composition which overcomes these disadvantages, and which has the general formula

[0005]

[Chemical 3]

(Here, R1 is a hydrogen atom or the same or different unsubstituted or substituted monovalent hydrocarbons, at least one of which is an unsaturated group; R2 and R3 are hydrogen atoms or the same or different unsubstituted or substituted monovalent hydrocarbons; monovalent hydrocarbon, n
is an integer of 1 to 3) and/or a partial hydrolyzate thereof as a main ingredient.

Specifically, the present inventors have conducted various studies on primer compositions that exhibit excellent adhesion even at high temperatures and in hot oil. It was discovered that when applied to a surface, this coated surface is firmly adhered to silicone rubber, and that this composition is easy to manufacture and stable in terms of quality control.
It is stable at temperatures above 200°C and in hot oil above 200°C, and furthermore, this composition has excellent air drying properties.
The primer layer is sufficiently cured before the bonding process and exhibits sufficient strength so that the flow of the rubber compound to be bonded will not cause the primer layer to peel off or fall off. −
The present invention was completed with the confidence that it could be used for molding, etc. This will be explained in further detail below.

[0008]

The present invention relates to a primer composition capable of firmly adhering silicone rubber to metal surfaces. The primer composition of the present invention is composed of an amino group-containing organosilicon compound represented by the above-mentioned general formula (I) as a main ingredient, and R1, R2, and R3 are hydrogen atoms, methyl groups, ethyl groups, Alkyl groups such as propyl and butyl groups, alkenyl groups such as vinyl and allyl groups, aryl groups such as phenyl and tolyl groups, cycloalkyl groups such as cyclohexyl groups, or carbon atoms of these groups. Chloromethyl group in which part or all of the hydrogen atoms are substituted with halogen atoms, cyano groups, etc., 3,3
, 3-trifluoropropyl group, cyanomethyl group, etc., and at least one of the R1 groups is reactive adhesive. must be an unsaturated group, and examples of this unsaturated group include vinyl group, allyl group,

[0009]

[C4]

(Here, R4 is a hydrogen atom or a methyl group,
m is an integer of 2 to 4).

After the primer composition of the present invention is applied to an adherend, it is simply air-dried to form a primer layer, and if necessary, an alkyl titanate, an organic Condensation catalysts such as tin compounds, amines, etc. may also be added. As mentioned above, this composition reacts with moisture in the air even at room temperature to form a cured film, so it is effective as a primer even if it is simply air-dried, but it cannot be heated even when used. good.

The cured film obtained by air drying or heating can be applied to a wide range of substrates such as metals, plastics, rubber, ceramics, etc., but it has particularly excellent adhesion to silicone rubber. Specific applications include fixing rolls for dry copying machines, adhesion of pressure roll cores and rubber, adhesion of lamination roll cores and rubber in the plastics industry, and automobiles. Manufacturing of composite oil seals and gaskets for industrial use, and manufacturing of various sheets and belts using metals, woven fabrics, etc. as base materials, etc.

[0013] The most suitable silicone rubber is an organic peroxide vulcanization type containing silica or an addition reaction type, but the silicone rubber is not limited thereto. It is also sufficiently effective for silicone rubber depending on the adherend, and can be applied not only to silicone rubber but also to non-silicone polymers such as urethane and polysulfide.

[0014] The primer composition of the present invention has extremely active silanol groups produced by its hydrolysis, and has a wider range of applicability and higher reliability than conventionally known primer compositions. Although it has the advantage of being highly adhesive, if it is further mixed into the rubber to be bonded, the rubber itself can be made into a self-adhesive rubber that has adhesive properties. This primer composition is applied to the first layer, and a conventional primer is applied to the second layer.
By performing this treatment, the performance of this conventional primer can be improved.

The amino group-containing organosilicon compound represented by the general formula (I), which is used as the main ingredient of the primer composition of the present invention, is easily synthesized by reacting the corresponding chlorosilane with the amino compound. This can be expressed, for example, by the formula (R1n)SiCl4-n+2(4-n)R2R3NH
→ (R1n)Si(NR2R3)4-n, but in this case, it is desirable to remove the remaining Cl groups with metal Mg, C2H5ONa, etc., if necessary.

[0016] In the primer composition of the present invention, the amino group-containing organosilicon compound represented by the above general formula (I) may be used alone, but it may also be used diluted with an organic solvent. , these organic solvents include toluene, xylene,
Examples include petroleum ethers, chlorinated hydrocarbons such as trichloromethane, esters such as ethyl acetate, ketones such as methyl ethyl ketone, and siloxane compounds such as hexamethyldisiloxane and dimethylsiloxane rings.

[0017]

[Examples] Next, examples of the present invention and comparative examples will be given. Example 1, Comparative Examples 1-2 Formula (CH2=CH)(CH3)2SiN(C2H5
) A dichloromethane solution (sample 1) containing 5% by weight of the amino group-containing organosilicon compound shown in 2 was prepared, and this was applied to a JIS H-4000, A-1050P aluminum plate and air-dried for 30 minutes. , silicone rubber KE-555U [Shin-Etsu Chemical Co., Ltd.] was applied to this coating surface.
A silicone rubber compound containing 0.6% by weight of dicumyl peroxide was adhered to the product (product name) to a thickness of 2 mm, and the pressure was 30 kg/cm2 and the temperature was 165 mm.
The samples were cured by hot pressing at ℃ for 10 minutes, and the air-drying properties of the samples, the strength of the film, the presence or absence of flow of the primer composition during press molding, and the initial adhesion of the molded products were determined. The results shown in 2 were obtained.

For comparison, the amino group-containing organosilicon compound used above was converted into a compound containing no unsaturated group and having the formula (
CH3)3SiN(C2H5)2 (sample 2), silicone resin containing methylvinyl polysiloxane and phenyl group, vinyltris(2-
When the same test as above was conducted on Primer A (Sample 3) consisting of methoxyethoxy) silane, fume silica, dicumyl peroxide, and tin dilaurate, the results shown in Table 1 below were obtained. Ta.

[0019]

[Table 1]

[Table 2]

Example 2 Structural formula

[C5]

A dichloromethane solution (sample 4) containing 7% by weight of the compound represented by the following formula was prepared, and its adhesive properties were examined in the same manner as in Example 1. The initial adhesive strength of this solution was 26 kg/25 mm. , 200℃
1 in dimethyl silicone oil (100 cS)
The adhesive strength after 2 days was 19 kgf/25 mm, and this product became tack-free within 10 minutes after application, and there were no problems with air drying.

Example 3 Structural formula

[C6]

A dichloromethane solution (Sample 5) containing 5% by weight of the compound shown below was prepared, and this was applied to the aluminum plate used in Example 1, air-dried for 60 minutes, and silicone rubber KE was applied to the applied surface. A silicone rubber compound containing 1% by weight of platinum catalyst C-10 [trade name manufactured by Shin-Etsu Chemical Co., Ltd.] and 2% by weight of crosslinking agent C-252P (trade name manufactured by Shin-Etsu Chemical Co., Ltd.) is added to -555u (previously described). Closely adhered to a thickness of 2mm, temperature 120℃, pressure 3
Cured by heating for 10 minutes under conditions of 0 kg/cm2,
When the adhesion of this product was examined, it showed good adhesion.
It had sufficient heat resistance and oil resistance in dimethyl silicone oil at .degree.

Example 4 Sample 1 prepared in Example 1 was applied onto an aluminum core having a diameter of 30 mm and a length of 300 mm, and after air drying for 30 minutes, the same formulation as shown in Example 1 was applied. KE555U silicone rubber compound with a thickness of 2m
When a roll for a dry type copying machine was made by injecting the primer into a roll, there was no flow of the primer layer at all, and the adhesion between the silicone rubber and the core metal in the roll obtained was also good.

[0025]

Effects of the Invention The present invention relates to a primer composition, which has the general formula as described above.

[0026]

[C7]

[0027] (wherein R1, R2, R3 are hydrogen atoms or monovalent hydrocarbon groups, R1 is an unsaturated group, and n is an integer of 1 to 3) This product is made from a compound as a main ingredient, but since this product contains an amino group and R1 contains an unsaturated group, when it is applied to a metal surface, the coated surface will firmly adhere to the silicone rubber. This adhesive surface is stable even in high-temperature oil at 200°C, and the primer layer does not peel off or fall off during adhesion, so it can be used for injection molding, transfer molding, etc., which is an advantage. It has a nature.

Claims (2)

[Claims] Claim 1: General formula [Formula 1] (where R1 is a hydrogen atom or the same or different unsubstituted or substituted monovalent hydrocarbon group, at least one of which is an unsaturated group, R2 and R3 are a hydrogen atom or Same or different unsubstituted or substituted monovalent hydrocarbon groups, n is 1 to 3
1. A primer composition comprising an amino group-containing organosilicon compound and/or a partial hydrolyzate thereof as a main ingredient. Claim 2: The unsaturated group is a vinyl group, an allyl group, [Formula 2] (where R4 is a hydrogen atom or a methyl group, and m is 2 to 5
The primer composition according to claim 1, wherein the primer composition is a group selected from the group consisting of: