JPH03247686A - Bonding organopolysiloxane composition and cured product thereof - Google Patents

Abstract

PURPOSE:To obtain the subject addition curing type composition, containing respective specific organopolysiloxane, organohydrogenpolysiloxane, platinum (compound)-based catalyst and modified organopolysiloxane and having high bonding durability and quality stability. CONSTITUTION:The objective composition containing (A) an organopolysiloxane having plural alkenyl groups and 100-200000cSt viscosity at 25 deg.C, (B) an organohydrogenpolysiloxane having plural H atoms bonded to Si in an amount so as to supply 0.6-6.0 aforementioned H atoms per alkenyl group in the component (A), (C) a platinum (compound)-based catalyst and (D) an unsaturated isocyanurate-modified organopolysiloxane expressed by the formula [R<1> is H, (substituted) alkyl, aryl or alkenyl and at least one thereof is alkenyl; R<2> and R<3> are H or (substituted) monofunctional hydrocarbon; a is an integer of 1-8; n is an integer of 0-100].

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an addition-curable organopolysiloxane adhesive composition and a cured product thereof.

(Prior Art) Addition-curing adhesive compositions based on organopolysiloxanes having vinyl groups bonded to silicon atoms are conventionally known, but these compositions still lack sufficient adhesive properties and are used, for example, in electrical It has drawbacks such as peeling of the cured silicone rubber during impregnation botting in coating parts.

In order to improve these drawbacks, it has been proposed to use various adhesion promoters together (Japanese Patent Publication No. 1350/1983).
No. 8, Special Publication No. 53-21026, Special Publication No. 59-521
No. 9, etc.).

Furthermore, in order to further improve adhesiveness, it has been proposed to incorporate ethylenically unsaturated isocyanurate (Japanese Patent Publication No. 55-41626).

(Problems to be Solved by the Invention) However, in the above-mentioned prior art, although the adhesive performance has been improved to some extent, the adhesive durability is still insufficient and the adhesive cannot be maintained under severe conditions such as submersion in water. As a result, peeling often occurs.

In addition, ethylenically unsaturated isocyanurates have poor compatibility with organopolysiloxanes, and triisocyanurates, which are said to have the greatest effect on improving adhesion, have a melting point of 26°C and crystallize in cold seasons. There were problems such as these, and there were major disadvantages when formulating and preparing the composition.

Therefore, an object of the present invention is to provide an addition-curable organopolysiloxane adhesive composition and a cured product thereof, which have significantly improved adhesive durability and stable quality.

(Means for Solving the Problems) The present invention significantly improves adhesive durability and quality stability of the composition by using polyorganosiloxane in which both ends of the molecular chain are modified with unsaturated isocyanurate. It was extremely successful.

According to the present invention, (A) has at least two alkenyl groups in one molecule and has a viscosity of 100 to 200,000 c at 25°C;
St organopolysiloxane, (B) having two or more hydrogen atoms bonded to silicon atoms in one molecule, and 0.6 to 6.0 hydrogen atoms per alkenyl group of the organopolysiloxane; Organohydrodiene polysiloxane in the amount to be supplied, (C) platinum or platinum compound catalyst, (D) the following formula, where R1 is a hydrogen atom, or an unsubstituted or substituted alkyl group, aryl group, or alkenyl group. and at least one of these R1 is an alkenyl group, R2 and R3 are a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, a is an integer of 1 to 8, and n is 0 An adhesive organopolysiloxane composition is provided, comprising: an unsaturated isocyanurate-modified organopolysiloxane having an integer of 100 to 100.

A Organopolysiloxane used as the main ingredient in the present invention has at least two alkenyl groups in one molecule and has a viscosity of 100 to 20 at 25°C.
It is in the range of 0,000 cSt.

In this case, examples of the alkenyl group include vinyl group, allyl group, methacrylic group, hexenyl group, etc.
In addition, organic groups other than alkenyl groups include alkyl groups such as methyl, ethyl, propyl and butyl groups, aryl groups such as phenyl and tolyl groups, and some or all of the hydrogen atoms of these groups may be substituted with halogen atoms, etc. may contain unsubstituted or substituted monovalent hydrocarbon groups such as groups substituted with (eg, chloromethyl group, trifluoropropyl group, etc.).

Such organopolysiloxanes are preferably linear diorganopolysiloxanes, and specific examples include the following.

However, in the above formula, P is 2 or 3, s, u and W are positive integers, and t.

■ and X are 0 or positive integers represents.

The above-mentioned organopolysiloxanes may be used alone or as a mixture of two or more, and may also have a partially branched structure.

In the present invention, the organohydrodiene polysiloxane of component (B) acts as a crosslinking agent for the alkenyl group-containing organopolysiloxane (A), which is the main ingredient,
Those having two or more hydrogen atoms bonded to silicon atoms in one molecule are used. This organohydrodiene polysiloxane (B) may have a linear, branched, or cyclic structure, or may be a mixture thereof. Specifically, the following can be exemplified.

However, in the above formula, b, c, d, e, f, g, and i represent 0 or a positive integer, and h represents an integer of 2 or more.

However, in the above formula, R4 is a hydrogen atom, an alkyl group, or
represents a monovalent hydrocarbon group such as a trimethylsiloxy group or a triorganosiloxy group such as a trimethylsiloxy group.

The organohydrodiene polysiloxane of component (B) is sufficient to supply 0.6 to 6.0 silicon-bonded hydrogen atoms per alkenyl group contained in the organopolysiloxane (A). amount, preferably 5
They are used in such a proportion that the ratio of i-H groups to alkenyl groups is from 1.2 to 4.0.

The platinum or platinum compound catalyst used in the present invention is an addition reaction catalyst and acts as a curing accelerator.

Examples of such catalysts include, but are not limited to, solid platinum supported on a carrier such as platinum black, alumina, or silica, chloroplatinic acid alcohol-modified chloroplatinic acid, and chloroplatinic acid and olefin. A complex of platinum and vinyl siloxane can be exemplified.

When using these catalysts, if they are solid catalysts, they must be crushed finely or crushed to improve dispersibility.
It is preferable that the carrier has a small particle size and a large specific surface area. In addition, regarding chloroplatinic acid or a complex of chloroplatinic acid and an olefin, these can be mixed with alcohol,
It is preferable to use it by dissolving it in a ketone, ether or hydrocarbon solvent.

The desired curing speed can be obtained by adjusting the amount of these catalysts used, but from an economic standpoint or to obtain a good cured product, it is preferable to use them in the following proportions. . That is, for substances compatible with the siloxane component such as chloroplatinic acid, the amount is 0.1 to 1 based on the total amount of the organopolysiloxane components (A) and (B).
For solid catalysts such as platinum black, it is preferably in the range of 20 to 500 ppm (in terms of platinum).

D Isocyanurate polyorganosiloxane The modified organopolysiloxane as component (D) used in the present invention is represented by the general formula [I] described above, that is, below.

In this formula [■], R1 represents a hydrogen atom, or an unsubstituted or substituted alkyl group, aryl group, or alkenyl group.

As the alkyl group, those having 1 to 20 carbon atoms are suitable, such as methyl, ethyl, and chloroethyl.

Provir, isopropyl, butyl, isobutyl.

Examples include pentyl, hexyl, dodecyl, and substituted alkyl such as cyanopropyl and dibromobutyl.

Aryl groups include phenyl, chlorophenyl,
Dibromophenyl, benzyl, etc. are listed.

Furthermore, the alkenyl group has 2 to 8 carbon atoms, and -
Specific examples include vinyl, allyl, butenyl, isobutenyl, pentenyl, and hexenyl, with allyl groups being preferred. In the present invention, it is most preferred that all four groups R1 are allyl groups.

R2 and R1 are hydrogen atoms or substituted or unsubstituted monovalent hydrocarbons containing no aliphatic unsaturated groups, and such monovalent hydrocarbon groups include methyl, ethyl, chloroethyl, cyanopropyl, and trivalent hydrocarbon groups. Examples include unsubstituted or substituted alkyl groups such as fluoropropyl, and unsubstituted or substituted aryl groups such as phenyl, chlorophenyl, and benzyl.

In addition, a is an integer from 1 to 8, and from the viewpoint of composition, 3
It is preferable that

n is an integer from 0 to 100, and is preferably 20 or less in terms of viscosity and blending amount.

Specific examples of the modified organopolysiloxane represented by the above-mentioned general formula [I] include the following.

C) lzCH=Ct(z H3 These component (D) isocyanurate-modified organopolysiloxanes are made by combining the corresponding unsaturated isocyanurate and a siloxane compound having Sin bonds at both ends of the molecular chain with a platinum catalyst. It is easily synthesized by subjecting it to an addition reaction in the presence of

These isocyanurate-modified organopolysiloxanes act as adhesion durability improvers, are liquid without crystallizing even at 0°C, and have good compatibility with the polysiloxanes of components (A) and (B). Are better. As a result, the composition of the present invention not only exhibits significantly excellent adhesive durability, but also effectively suppresses separation of the components during its preparation and storage, and has stable quality.

In the present invention, the isocyanurate-modified organopolysiloxane as the component (D) described above is 1 to 50 parts by weight per 100 parts by weight of the organopolysiloxane as the component (A).
In particular, it is preferable to mix it in a proportion of 4 to 30 parts by weight.

If the amount used is less than 1 part by weight, it may be difficult to achieve the objective of the present invention, which is to improve properties such as adhesive durability, and if it is used in an amount greater than 50 parts by weight. In addition to being economically disadvantageous, other physical properties may be impaired.

In the present invention, in addition to the cyanurate-modified organopolysiloxane of component (D) described above, if necessary, one or more silicon-bonded hydrogen atoms are present in one molecule, and an alkoxy group and At least one epoxy group
By using an organopolysiloxane having seeds in combination, it becomes possible to significantly improve adhesiveness. This organopolysiloxane acts to improve self-adhesion to a predetermined base material, and is known per se.

For example, those having an alkoxysiloxy group disclosed in Japanese Patent Publication No. 53-21026, those having an epoxy-containing hydrocarbon group disclosed in Japanese Patent Publication No. 53-13508, and those having an epoxy-containing hydrocarbon group disclosed in Japanese Patent Publication No. 53-13508.
Those having an alkoxysiloxy group and an epoxy-containing hydrocarbon group as disclosed in No. 219 are preferably used. More specifically, although not limited thereto, the following silicon compounds can be exemplified.

＼ / These can also be used by increasing the degree of polymerization as appropriate depending on the purpose.

The above-mentioned organopolysiloxane may be used in an amount of 0 to 100 parts by weight per 100 parts by weight of the organopolysiloxane of component (A), if necessary.
It can be used in a proportion of 20 parts by weight, preferably 0.5 to 10 parts by weight.

In addition, in the composition of the present invention, depending on its use etc.,
Various additives such as fillers can be added.

For example, as fillers, all those commonly used for addition-type silicone rubber compositions can be used, and specifically, fumed silica, precipitated silica, hydrophobized silica, carbon black, titanium dioxide, Ferric oxide, aluminum oxide, zinc oxide, quartz powder, diatomaceous earth, calcium silicate, talc, bentonite, asbestos, glass fiber, organic fiber, etc. are used alone or in combination of two or more.

The amount of the filler to be blended is arbitrary as long as it does not impair the object of the present invention, but for boat fishing it should be 600 parts by weight or less per 100 parts by weight of the organopolysiloxane of component (A). Among these, it is preferable that the amount of fumed silica is 25 parts by weight or less, and in the case of alumina etc., it is preferably 30 parts by weight.
A range of 0 to 500 parts by weight is suitable, and the suitable addition amount varies depending on the oil absorption, surface area, specific gravity, etc. of the filler.

In addition, in order to reinforce the strength of the cured product, special public Sho 3B-2
SiO□ unit disclosed in No. 6771, Japanese Patent Publication No. 45-9476, etc., CHz=CH(R' z)-SiOo
, s units and R', -5iO0,5 units (R' is a monovalent hydrocarbon group containing no unsaturated aliphatic group) organopolysiloxanes having a resin structure can also be added.

Furthermore, for the purpose of controlling the curing speed of the composition,
CH,=CHR”SiO disclosed in No. 10947
organopolysiloxanes containing units (R'' is the same as R'' above), acetylenic compounds disclosed in U.S. Pat. No. 3,445,420, and U.S. Pat. No. 3,532.
The ionic compounds of heavy metals disclosed in No. 649 can be blended, and non-functional organosiloxanes can also be blended in order to improve the thermal shock resistance, flexibility, etc. of the cured product.

Furthermore, if necessary, coloring agents such as red iron oxide, black red iron oxide, cerium oxide, heat resistance improvers, carbon, titanium oxide, etc.
Flame retardant agents such as benzotriazole, zinc carbonate, and manganese carbonate, addition reaction control agents such as vinyl group-containing siloxane and acetylene compounds, and blowing agents may also be appropriately blended.

(Effects of the Invention) The adhesive organopolysiloxane composition of the present invention easily and firmly adheres not only to metals but also to various engineering plastics such as polyethylene terephthalate, polybutylene terephthalate, phenol resin, and epoxy resin. Moreover, the adhesive durability was also significantly improved.

Furthermore, the both terminally modified organopolysiloxane of the present invention has 0
Since it is liquid even at °C, it is easy to prepare formulations during cold seasons, making it very industrially advantageous.

Therefore, according to the present invention, it has become possible to apply an addition-curable organopolysiloxane adhesive composition to an extremely wide variety of uses.

(Example) In the following examples, all "parts" mean parts by weight, and all viscosities are values at 25°C.

Synthesis Example 1 Synthesis of CHzCH=C)lz (Dl) 100 g (0.40 mol) of triallylisocyanurate, 200 g of dry toluene and 0.5% platinum chloride in 500 mf four rosette parapet flasks. 0.2g of acid alcohol solution was charged, heated to 80°C, 42g (0.44 mol) of dimethylchlorosilane was added dropwise, and the mixture was heated at 80°C for 2 hours.
The reaction was completed at C. After that, unreacted substances were removed using a strip, and then the pressure was set at 4×10 torr.

At 130°C CH.

C and 2 ＼ ／ ＼ ONゝ0 H2CH CH2 124g was obtained.

Compound (Di) 10, which is a colorless transparent viscous liquid, is obtained by hydrolysis, neutralization, washing with water, and dry filtration.
1g was collected.

Synthesis Example 2 Synthesis of cnzco=cnz (D2) 100 g (0.40 mol) of triallylisocyanurate, 200 g of dry toluene and 0.5% chloroplatinic alcohol in 4 500+wA rosetteable flasks. After charging 0.2 g of the solution and heating it to 100''C, 150 g (0.26 mol) of organosiloxane expressed by the average formula was added dropwise, and the reaction was completed at 100°C for 6 hours.

After cooling, 3 g of activated carbon was added and the mixture was stirred for 8 hours at 25°C. After filtering, 20 torr, 170°
At step C, unreacted materials were stripped off, and 210 g of compound (D2), which was a colorless transparent viscous liquid, was collected.

The following ingredients are used for back coating: Dimethylpolysiloxane 100 parts Both ends are blocked with dimethylvinyl groups Viscosity: 5000 cSt Made silica 15 parts Surface hydrophobized with trimethylsilyl groups Specific surface area: 300 m''/g Octatool solution of chloroplatinic acid 0.02 part 2% by weight
platinum-containing 3-methyl-3-hydroxy-1-butyne (control agent)
0.005 part was added and mixed uniformly.

Furthermore, 2.5 parts of an organohydrodiene polysiloxane represented by the following average formula (1), 3.0 parts of an organopolysiloxane represented by the following formula (II), and - both terminals synthesized in Synthesis Example 1 Modified organopolysiloxane (D
1.5 parts of 1) were added and mixed to prepare an adhesive composition (a).

After curing this composition (A) at 120°C/60 minutes, the physical properties of the rubber were measured according to JIS K-6301, and the shear adhesive strength with various adherends and its water immersion durability were measured. It was measured. The measurement results are shown in Table 1.

JliJu The following two types of dimethylpolysiloxane are used as the main ingredient.

CH3 (a): Clh CH-Si- at both ends of the molecular chain, and an average of one 5'i0- + in the molecule, 30,0OO
cS t viscosity CH=CH! Something that has a degree.

CH3 (b); has CUt·CH-5i- at both ends of the molecular chain and has a viscosity of 600 cS tH3.

The following components: Dimethylpolysiloxane (a) Dimethylpolysiloxane, etc.) Alumina (average particle size 5 μm) Octatotool solution of chloroplatinic acid (same as Example 1) 50 parts 50 parts 300 parts 0.1 part 3-methyl -3-hydroxy-1-butyne (control agent)
0.03 part was added and mixed uniformly.

Furthermore, 4.4 parts of organohydrodiene polysiloxane represented by the following average composition formula (I 3.0 siloxane (D2)
An adhesive composition (0) was prepared by adding and mixing the following components.

(In) (IV) This composition (II) was cured at 130° C. for 30 minutes, and the rubber physical properties and adhesive strength were measured in the same manner as in Example 1.

The measurement results are shown in Table 1.

Comparative Example 1.2 Comparative compositions a and b were prepared in the same manner as in Example 1 and Example 2 without using both end-modified organopolysiloxanes (DI) and (D2), respectively, and the same compositions were prepared. Measurements were made. The measurement results are also shown in Table 1.

Claims (2)

[Claims] (1) (A) has at least two alkenyl groups in one molecule and has a viscosity of 100 to 200,000 at 25°C
cSt organopolysiloxane, (B) having two or more hydrogen atoms bonded to silicon atoms in one molecule, and 0.6 to 6.0 hydrogen atoms per alkenyl group of the organopolysiloxane; Organohydrogenpolysiloxane in the amount to be supplied, (C) Platinum or platinum compound catalyst, (D) General formula below, ▲ Numerical formula, chemical formula, table, etc. ▼ In the formula, R^1 is a hydrogen atom or unsubstituted or a substituted alkyl group, aryl group, or alkenyl group, and at least one of these R^1 is an alkenyl group, and R^2 and R^3 are a hydrogen atom or a substituted or unsubstituted group. an unsaturated isocyanurate-modified organopolysiloxane represented by Polysiloxane composition. (2) A cured product obtained by curing the composition according to claim (1).