JPH0825581A - Laminate improved in heat resistance - Google Patents

Abstract

PURPOSE:To obtain a silicone laminate capable of keeping its good performance at 300 deg.C for a long term. CONSTITUTION:A laminate is molded using 100 pts.wt. A) organopolysiloxane represented by a composition formula (I) R<1>a Si(OR<2>)bO(4-a-b)/2(in the formula, R<1> is alkyl having 1-10 carbon atom or phenyl, R<2> is hydrogen atom or alkyl having 1-4 carbon atoms, R<1>, R<2> each may be different in one molecule, (a) is 0.8-1.2, and (b) is 0.01-0.4), 0.05-5 pts.wt. organic metallic compound of a metallic element selected out of Mg, Al, Ti, Mn, Fe, Co, Zn, Zr, Ce, and Sn, and C) a substrate. Furthermore, a laminate is molded using A)-C) and D) a silane and/or the partially hydrolyzed condensate thereof selected out of an amino- containing alkoxysilane, epoxy-containing alkoxysilane, and the partially hydrolyzed condensate thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicone-based laminate, and more particularly to a silicone-based laminate which has improved heat resistance and can be used in applications where the use conditions are severe.

[0002]

2. Description of the Related Art Conventionally, a laminate obtained by impregnating a glass fiber cloth with an organopolysiloxane and molding is flame-retardant,
It has excellent heat resistance and various electrical properties at high temperatures, and has been used as a material for electrical products since ancient times. However, there are problems such as poor workability at the time of manufacturing a laminated plate, low mechanical strength of the laminated plate, and poor processing characteristics, and many improvements have been made so far. For example, Japanese Examined Patent Publication No. 30-829 discloses that workability is improved by using a curing catalyst such as amines and metal compounds. In addition, JP-B-58-55984 and JP-A-51-137751 use an addition reaction type organopolysiloxane,
It is disclosed that high-pressure molding and post-curing that deteriorate workability are unnecessary and mechanical strength is further improved.
JP-B-36-13536 and JP-B-52-36905 disclose improvement in workability as a printed wiring board, and JP-B-60-28665 discloses a method that does not use a solvent in consideration of the environment. Has been done. Further, as a method of improving the mechanical strength, a method of treating a glass fiber base material with a silane coupling agent is known, and particularly, an amino group-containing alkoxysilane has a large effect of improving the mechanical strength and acts as a curing agent. It is widely used, but it has been a cause of adversely affecting heat resistance. Furthermore, the epoxy group-containing alkoxysilane also has the effect of increasing stress,
After all, there was a problem in heat resistance.

At the present time, as the applications of laminated boards have expanded, the required performance has become severe. Therefore, the above improvement may not be sufficient in some cases. For example, regarding heat resistance, it is required to maintain good performance at a temperature of 300 ° C or higher for a long period of time. This heat resistance improvement is disclosed in, for example, Japanese Patent Laid-Open No. 3-287628, but it is a range that can withstand a soldering process as a printed circuit board, and is still a laminate having sufficient performance in terms of long-term heat resistance. Currently, no boards have been obtained.

[0004]

From such a situation,
The inventors of the present invention maintain good performance at a temperature of 300 ° C. or higher for a long time, specifically, the bending strength reduction rate after heat treatment at 350 ° C. for 1,000 hours is 50% or less.
The present invention was made in an attempt to realize a silicone-based laminate.

[0005]

Means for Solving the Problems The present invention has solved the above-mentioned problems. First, the laminated plate of the present invention comprises: A) a composition formula (I) R ¹ _a Si (OR ² ) _b O _{( 4-ab) / 2} ... (I) (In the formula, R ¹ represents an alkyl group having 1 to 10 carbon atoms or a phenyl group, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ¹ , R ² may be different in one molecule, a is 0.8 to 1.2, and b is 0.01 to 0.4).
100 parts by weight, B) 0.05 to 5 parts by weight of an organometallic compound of a metal element selected from Mg, Al, Ti, Mn, Fe, Co, Zn, Zr, Ce and Sn and C) a base material and molded. It is characterized by that. Second
In addition to the organopolysiloxane of A), the organometallic compound of B) and the base material of C), a silane selected from D) an amino group-containing alkoxysilane, an epoxy group-containing alkoxysilane, and a partial hydrolyzed condensate thereof. And / or a partial hydrolysis-condensation product thereof, based on A) above,
0.5 to 5.0 parts by weight per part by weight and / or 0.1 to 1.0 g per 1 m ^{2 of the} above C) are applied and used for molding.

The present invention will be described in more detail below. The laminate of the present invention is produced from the composition (binder) containing the components A) and B) and the base material of C). Among these, the component A) is an organopolysiloxane represented by the composition formula (I), has a silanol group or an alkoxyl group as a functional group, and can be cured by a treatment such as heating.

The content of the functional group is defined by b in the composition formula (I), but if b is less than 0.01, the curing will be insufficient and the mechanical strength of the resulting laminate will decrease. When b is larger than 0.4, too much water or alcohol is generated during curing, which weakens the interlaminar adhesion of the laminate and lowers the strength. Such an organopolysiloxane has a small molecular weight and is too low in viscosity to be glass. Workability at the time of application to the fiber or press hardening may be deteriorated. Therefore, the range of b is 0.01 to 0.4.

An alkyl group directly bonded to a silicon atom and /
Alternatively, the number of phenyl groups is defined by a in the composition formula (I), but when a is smaller than 0.8, heat resistance is improved, but the cured product becomes brittle and the strength of the laminated plate is reduced. 1.2
If it is larger than the above range, the organic component becomes too much and the heat resistance is deteriorated. Therefore, the range of a is set to 0.8 to 1.2. Examples of R ¹ include an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a pentyl group and a hexyl group, and a phenyl group. From the industrial point of view, a methyl group and a phenyl group are suitable, and a methyl group is preferred especially when it is necessary to have low flame retardancy and smoke emission.

The degree of polymerization of the organopolysiloxane represented by the composition formula (I) is preferably 1,000 to 50,000 in terms of average molecular weight. A known method can be used to obtain such an organopolysiloxane. For example, a hydrolyzable group such as a halogen or an alkoxyl group directly bonded to a silicon atom may be added in an amount of 2 to 4
The individual silane monomer is mixed with water in the presence of a hydrolytic condensation catalyst such as an acid, if necessary, and usually 1 to 10 at 10 to 100 ° C.
React for hours. At that time, an organic solvent can be used for the purpose of adjusting workability and polymerization degree of the product.

The organometallic compound which is the component B) of the composition has been found in the tests of various additives, and the present inventors have found that Mg, Al, Ti, M in the organometallic compound were found.
It has been found that only organometallic compounds of n, Fe, Co, Zn, Zr, Ce and Sn have the effect of improving the heat resistance of the laminate. As the component B), those which are commercially available can be used, and examples thereof include alcoholate bound to a propoxy group or butoxy group, a carboxylate bound to acetic acid or octylic acid, and a chelate compound bound to acetoacetic acid ester or acetylacetone. To be From the viewpoints of coloring, curing characteristics, and workability, organometallic compounds of Al, Zn, and Ce are easy to use, and particularly considering the heat resistance, the organometallic compounds of Ce are preferable.
As the component B), these organometallic compounds may be used alone or in combination of two or more kinds. Further, a curing agent such as an acid or an alkali may be used together if necessary.

The mixing ratio of the component B) to the component A) is
0.05 to 5 parts by weight of the component B) is added to 100 parts by weight of the component A). If the amount is less than 0.05 parts by weight, insufficient curing and reduced heat resistance are observed, which is disadvantageous in that it takes a long time to cure. On the other hand, if it is more than 5 parts by weight, the laminate becomes brittle and the strength is lowered.

The base material of C) is most commonly made of glass fiber, but it is also possible to use a base material made of an inorganic material such as asbestos or ceramics or a heat resistant organic polymer such as polyamide. Examples of the form of the substrate include cloth, mat, and yarn, and any of them can be used, and these can be selected from commercially available products.

Further, in the present invention, it is preferable to use a silane selected from amino group-containing alkoxysilanes, epoxy group-containing alkoxysilanes and partial hydrolysis-condensation products thereof and / or partial hydrolysis-condensation products thereof as component D). It has been found that results are obtained. Examples of the amino group-containing alkoxysilane include γ-aminopropyltriethoxysilane and N- (β-aminoethyl)-
Examples of the epoxy group-containing alkoxysilane such as γ-aminopropyltrimethoxysilane include γ-glycidoxypropyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane.
These can be used in the form of their partially hydrolyzed condensates, or silane and their partially hydrolyzed condensates can be used in combination.

These silanes or their partial hydrolysis-condensation products can be added to the composition (binder) consisting of the components A) and B) or can be used to pretreat the substrate of C). Good. When it is added to the binder, it is preferably 0.5 to 5.0 parts by weight with respect to 100 parts by weight of the component A). If it is less than 0.5 part by weight, a sufficient strength improving effect cannot be obtained, and if it is added more than 5.0 parts by weight, no further effect can be expected and the unreacted material adversely affects the heat resistance. When the substrate is pretreated, 0.1 to 1.0 g of silane and / or its partial hydrolysis-condensation product may be applied per 1 m ^{2 of the} substrate. Further, both addition into the binder and substrate treatment may be performed. Such silane is conventionally known as a cause of adversely affecting heat resistance, but when the organometallic compound selected as the component B) is combined, no unexpected decrease in heat resistance is observed. Since silane also exerts its original effect as a silane coupling agent, the synergistic effect of the two as a whole makes it superior to conventional products as well as combinations of binders consisting of components A) and B) with untreated base materials. It was found that a laminate having mechanical strength and heat resistance can be obtained.

As described above, when a specific amount of a specific organometallic compound is used, the heat resistance of the laminate is improved, and by further combining a specific silane and / or its partial hydrolysis-condensation product with this organic metal compound. It was found that not only the adverse effect on the heat resistance of silane is suppressed but also the strength improving effect is maintained even at high temperatures. That is, since the laminate of the present invention has a bending strength reduction rate of 50% or less after heat treatment at 350 ° C. for 1,000 hours, it is required to maintain good performance at a temperature of 300 ° C. or higher for a long time. It can also be used for applications with severe usage conditions.

A known method can be used to prepare a silicone laminate using the composition containing the components A) and B), the substrate of C) and the component D).
The components A) and B) are treated prior to the treatment of the substrate.
An inorganic filler such as silica or quartz powder may be added to the composition containing the components, or an organic solvent such as toluene, xylene, isopropanol, acetone or ethyl acetate may be added from the viewpoint of workability of the treatment. However, the viscosity may be adjusted to an appropriate value. After blending, use by three-roll or ball mill to disperse and mix until uniform.

In order to produce a laminated plate, first, a substrate is coated with or impregnated with the above composition to prepare a prepreg, which may be carried out by a conventional method. Next, after pre-curing the dried prepreg at a prescribed temperature (about 130 ° C is suitable), a prescribed number of layers are piled up and the temperature is 150 to 200 ° C, and the pressure is 5 to 100 ° C.
Curing may be performed for 30 minutes to 3 hours at kg / cm ² .

[0018]

EXAMPLES Next, examples of the present invention will be described. In addition,% in an example represents weight%. (Synthesis example 1) 200 g of methyltrimethoxysilane, 60 g of dimethyldimethoxysilane, 40 g of ethyl orthosilicate, xylene
300 g was placed in a 1 L flask, and 70 g of 1% hydrochloric acid was mixed with stirring. The temperature rose from 30 ° C to 45 ° C. Stirring was continued for 2 hours as it was to ripen. Add 100 g of 10% Na ₂ SO ₄ water.
After stirring for 30 minutes, the lower aqueous layer that separated by standing was removed. This water washing operation was repeated 3 times to obtain a 30% xylene solution of organopolysiloxane. 80 from this solution
Xylene was distilled off under conditions of 50 ° C. and 50 mmHg to obtain a 50% solution.
The resulting organopolysiloxane had 4% silanol groups, 2% methoxy groups and 0.5% ethoxy groups as functional groups.
% Included. Analysis by gel permeation chromatography revealed that the styrene-equivalent molecular weight was about 10,000.

(Synthesis Example 2) Phenyltrimethoxysilane
100g, methyltrimethoxysilane 180g, orthosilicate
30 g and 300 g of xylene were placed in a 1 L flask and treated in the same manner as in Synthesis Example 1. The xylene solution of organopolysiloxane obtained after washing with water had a concentration of 35%. This was concentrated to a 50% solution as in Synthesis Example 1. The obtained organopolysiloxane has 5 silanol groups as functional groups.
%, 3% of methoxy groups and 0.5% of ethoxy groups. The gel permeation chromatograph analysis revealed a styrene-equivalent molecular weight of about 7,000. The gel permission chromatographs in Synthesis Examples 1 and 2 were measured using HLC-802A [manufactured by Tosoh Corporation]. The solvent was THF and the flow rate was 1.0 ml / min, and the temperature was 38 ° C.

Examples 1 to 11 200 g of component A) shown in Table 1 or Table 2 (50% solution obtained in Synthesis Example 1 or 2) and dry silica fine powder (trade name: Aerosil A-300, Japan) Aerosil Co., Ltd.) 50 g and well mixed with a triple roll, and then component B) shown in Table 1 or Table 2 and isopropyl alcohol 50 g
Was added and mixed to obtain a coating liquid. A glass cloth [trade name: WE18GT, manufactured by Nitto Boseki Co., Ltd.] was impregnated with this coating solution, air-dried for 1 hour, and then precured at 100 ° C. for 10 minutes to obtain a prepreg. Ten of these prepregs were stacked and press-cured at 180 ° C. and 50 kg / cm ² for 1 hour to obtain a laminated plate. The thickness of the laminate was 1.5 mm.

Comparative Examples 1 to 7 Using 200 g of the component A) (50% solution obtained in Synthesis Example 1 or 2) shown in Table 1 or Table 2 respectively, B) and D shown in Table 1 or Table 2 were used. ) A coating liquid was prepared and a laminate was prepared in the same manner as in Examples 1 to 11 with or without using the component (or other kind of additive).

Examples 12 to 14 Component A) shown in Table 3 (Synthesis Example 1 or 2)
200% of the 50% solution obtained in step 1) and component B) were used, and
A coating solution was prepared by blending in the same manner as in 1. Using silane-treated glass cloth obtained by spray-coating glass cloth (WE18GT above) with 0.5 g per m ² of γ-aminopropyltriethoxysilane as a component and air-drying at room temperature for 1 hour. Laminates were prepared in the same manner as in Examples 1 to 11 using the above coating solution.

Comparative Examples 8 to 10 Component A) shown in Table 3 (Synthesis Example 1 or 2)
A coating solution was prepared in the same manner as in Examples 12 to 14, using 200 g of the 50% solution obtained in step 1), no components B) and D) or only component D) shown in Table 3. Similarly, a silane-treated glass cloth was prepared and a laminated plate was prepared.

Example 15 A coating solution was prepared by using 200 g of the 50% solution obtained in Synthesis Example 1 as the component A) and 0.5 g of octylic acid Ce as the component B) in the same manner as in Examples 1 to 11. . Glass cloth (W above)
E18GT) 0.5 g / m ² γ-as D) component
A silane-treated glass cloth obtained by spray-coating glycidoxypropyltrimethoxysilane and then air-drying at room temperature for 1 hour was used to prepare a laminate using the above coating solution in the same manner as in Examples 1 to 11. .

Comparative Example 11 As the component A), 200 g of the 50% solution obtained in Synthesis Example 1 was used,
A coating solution was prepared in the same manner as in Example 15, except that 0.2 g of N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane as the component D) was used without using the component B). A silane-treated glass cloth was prepared and a laminated plate was prepared.

Examples 16 and 17 200 g of 50% solution obtained in Synthesis Example 1 as component A)
Using 0.5 g of octylate Ce as component B), 0.5 g of γ-glycidoxypropyltrimethoxysilane in Example 16 and 5.0 g of the same silane in Example 17 as component D). A coating solution was prepared in the same manner as in 1 to 11 to prepare a laminated plate.

A heat resistance test was conducted on the laminates obtained in the above Examples and Comparative Examples. The laminated plate was cut into a rectangle of 50 mm x 25 mm to make a test piece, and the change with time when heated in an electric furnace at 350 ° C was traced by the change in bending strength and appearance. The results are also shown in Tables 1 to 3. The bending strength was measured with an autograph IM-100DS manufactured by Shimadzu Corporation. The appearance was evaluated as ◯ for glossy, Δ for almost no gloss, and x for chalking, cracks, or peeling between layers.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

EFFECTS OF THE INVENTION The present invention provides a silicone resin laminate having excellent heat resistance, which exhibits a flexural strength reduction rate of 50% or less even after heat treatment at 350 ° C. for 1,000 hours. in this way,
Since the silicone resin laminate of the present invention has higher heat resistance than conventional ones, the effect of the present invention is extremely large.

Claims (3)

[Claims] 1. A) Composition formula (I) R ¹ _a Si (OR ² ) _b O _{(4-ab) / 2} ... (I) (wherein R ¹ is an alkyl group having 1 to 10 carbon atoms). Or a phenyl group, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and each of R ¹ and R ² may be different in one molecule, a is 0.8 to 1.2, and b is 0.01 ~ 0.4) Organopolysiloxane represented by
100 parts by weight, B) 0.05 to 5 parts by weight of an organometallic compound of a metal element selected from Mg, Al, Ti, Mn, Fe, Co, Zn, Zr, Ce, Sn and C) a base material, and molded A laminated board characterized by the above. 2. A) Composition formula (I) R ¹ _a Si (OR ² ) _b O _{(4-ab) / 2} ... (I) (wherein R ¹ is an alkyl group having 1 to 10 carbon atoms). Or a phenyl group, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and each of R ¹ and R ² may be different in one molecule, a is 0.8 to 1.2, and b is 0.01 ~ 0.4) Organopolysiloxane represented by
100 parts by weight, B) 0.05 to 5 parts by weight of an organometallic compound of a metal element selected from Mg, Al, Ti, Mn, Fe, Co, Zn, Zr, Ce, Sn, C) base material and D) amino group-containing A silane selected from an alkoxysilane, an epoxy group-containing alkoxysilane and a partial hydrolysis-condensation product thereof and / or a partial hydrolysis-condensation product thereof A).
0.5 to 5.0 parts by weight per 100 parts by weight thereof and / or 0.1 to 1.0 g per 1 m ^{2 of the} above C) is applied and molded to obtain a laminate. 3. The laminate according to claim 1, which has a bending strength reduction rate of 50% or less after heat treatment at 350 ° C. for 1,000 hours.