JP3031821B2 - Laminates with improved heat resistance - Google Patents

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 severe use conditions.

[0002]

2. Description of the Related Art Conventionally, a laminate obtained by impregnating a glass fiber cloth with an organopolysiloxane and molding the same has flame retardancy,
It has excellent heat resistance and various electrical properties at high temperatures, and has been used for a long time as a material for electrical products. However, there are problems such as poor workability in manufacturing a laminate, poor mechanical strength of the laminate, and poor processing characteristics, and many improvements have been made so far. For example, Japanese Patent Publication No. Sho 30-829 discloses that workability is improved by using a curing catalyst such as an amine or a metal compound. 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 cure, which deteriorate workability, are not required, and further, mechanical strength is improved.
JP-B-36-13536 and JP-B-52-36905 disclose the improvement of workability as a printed wiring board, and JP-B-60-28665 discloses a method that does not use a solvent due to environmental considerations. Have been. Also, as a method of improving mechanical strength, a method of treating a glass fiber base material with a silane coupling agent is known, and in particular, an amino group-containing alkoxysilane has a large effect of improving mechanical strength and acts as a curing agent. Although it is widely used, it has a bad influence on heat resistance. Furthermore, epoxy group-containing alkoxysilanes also have the effect of increasing stress,
Again, there was a problem with heat resistance.

[0003] At present, the required performance is becoming severer with the expansion of applications of the laminate. Therefore, the above improvement may not be sufficient in some cases. For example, with respect to heat resistance, it is required to maintain good performance at a temperature of 300 ° C. or more for a long period of time. The improvement of the heat resistance is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-287628, but it is within a range that can withstand a soldering process as a printed circuit board, and has a sufficient performance in terms of long-term heat resistance. At present, no board has been obtained.

[0004]

SUMMARY OF THE INVENTION Under such circumstances,
The present inventors maintain good performance over a long period of time at a temperature of 300 ° C. or more, specifically, such that the bending strength reduction rate after heat treatment at 350 ° C. for 1,000 hours is 50% or less.
The present invention was made to realize a silicone laminate.

[0005]

According to the present invention, there is provided a laminate comprising 100 parts by weight of the organopolysiloxane of A) and 0.05% of the organometallic compound of B).
D) a coating solution comprising 0.5 to 5.0 parts by weight of a silane selected from amino group-containing alkoxysilanes, epoxy group-containing alkoxysilanes and partially hydrolyzed condensates thereof and / or partially hydrolyzed condensates thereof; A) a laminate to be coated or impregnated on a substrate and molded; and a coating liquid comprising the components A) and B), and the component D) to the substrate C) in an amount of 0.1 / m ^2.
~ 1.0 g, applied or impregnated,
A laminate to be molded; a coating liquid comprising the components A), B) and D) is applied or impregnated to a component obtained by applying the component D) to the substrate C) at a rate of 0.1 to 1.0 g per 1 m ² and molded. It is a laminated plate to be.

Hereinafter, the present invention will be described in more detail. The laminate of the present invention is produced from the composition (binder) containing the components A), B) and D ) and the base material of the component C). 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 determined by b in the composition formula (I). If b is less than 0.01, the curing becomes insufficient, and the mechanical strength of the obtained laminate decreases. On the other hand, if b is larger than 0.4, too much water or alcohol is generated at the time of curing, so that the interlayer adhesion of the laminate is weakened and the strength is reduced. In some cases, the workability during application to fibers and press hardening is deteriorated. Therefore, the range of b is set to 0.01 to 0.4.

An alkyl group directly bonded to a silicon atom and / or
Alternatively, the number of phenyl groups is defined by a in the composition formula (I). If a is smaller than 0.8, the heat resistance is improved, but the cured product becomes brittle, and the strength of the laminate decreases. 1.2
If it is larger than this, the organic component becomes too large and the heat resistance deteriorates. 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. Industrially, a methyl group and a phenyl group are suitable, and a methyl group is particularly preferred when low flame retardancy and low smoke emission are required.

The degree of polymerization of the organopolysiloxane represented by the composition formula (I) is preferably from 1,000 to 50,000 in average molecular weight. A known method can be used to obtain such an organopolysiloxane. For example, when a hydrolyzable group such as a halogen or an alkoxyl group directly bonded to a silicon atom is
The silane monomer having a single unit is mixed with water, if necessary, in the presence of a hydrolysis and condensation catalyst such as an acid.
Let react for hours. At that time, an organic solvent can be used for adjusting the workability and the degree of polymerization of the product.

The organometallic compound which is the component B) of the composition has been found by testing various additives, and the present inventors have found that Mg, Al, Ti, M
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 available on the market can be used, and examples thereof include alcoholates bonded to propoxy and butoxy groups, carboxylate salts bonded to acetic acid and octylic acid, and chelate compounds bonded to acetoacetate and acetylacetone. Can be The organometallic compounds of Al, Zn, and Ce are easy to use from the viewpoint of coloring, curing characteristics, and workability, and the organometallic compounds of Ce are particularly preferable in consideration of heat resistance.
As the component (B), these organometallic compounds can be used alone or in combination of two or more. Further, a curing agent such as an acid or an alkali may be used in combination as needed.

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

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

Furthermore, in the present invention, it is preferable to use a silane selected from amino group-containing alkoxysilane, epoxy group-containing alkoxysilane and its partially hydrolyzed condensate and / or its partially hydrolyzed condensate 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)-
Epoxy group-containing alkoxysilanes 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 silanes and their partially hydrolyzed condensates can be used in combination.

These silanes or partially hydrolyzed condensates thereof can be added to a composition (binder) comprising the components A) and B), or can be used for treating the base material of C) in advance. Is also good. When added to the binder, the amount is preferably 0.5 to 5.0 parts by weight based on 100 parts by weight of component A). If the amount is less than 0.5 part by weight, a sufficient strength improving effect cannot be obtained. If the amount is more than 5.0 parts by weight, no more effect can be expected, and unreacted materials adversely affect heat resistance. If the advance treating a substrate may be 0.1~1.0g applied as the substrate 1 m ² per silane and / or partial hydrolysis condensate thereof. Further, both the addition into the binder and the substrate treatment may be performed. Such silanes are conventionally known as a cause of adversely affecting heat resistance. However, when the organometallic compound selected as the component (B) is combined, the heat resistance is not unexpectedly reduced. Since silane also exerts its effect as an original silane coupling agent, the synergistic effect of the two as a whole is superior to the combination of a conventional product and a binder composed of components A) and B) and an untreated substrate. It has been 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 further, a specific silane and / or a partial hydrolysis condensate thereof is combined with the organometallic compound. It has been found that not only the adverse effect of silane on the heat resistance 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 not more than 50% after heat treatment at 350 ° C. for 1,000 hours, it is required to maintain good performance for a long time at a temperature of 300 ° C. or more. In addition, it can sufficiently cope with applications under severe use conditions.

A known method can be used to prepare a silicone laminate using the composition containing the components A) and B), the base material of the component C), and the component D).
Prior to treating the substrate, the component A) and the component B)
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 is added from the viewpoint of workability. The viscosity may be adjusted to an appropriate value. After blending, the mixture is dispersed and mixed using a three-roll mill or a ball mill until it becomes uniform.

In order to produce a laminate, first, a prepreg is prepared by applying or impregnating the above-mentioned composition onto a substrate, which may be carried out by a conventional method. Next, the dried prepreg is pre-cured at a predetermined temperature (approximately 130 ° C. is appropriate).
The curing may be performed at kg / cm ² for 30 minutes to 3 hours.

[0018]

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 to ripen. 100g of 10% Na ₂ SO ₄ water
After stirring for 30 minutes, the mixture was allowed to stand, and the lower aqueous layer that separated was removed. This water washing operation was repeated three times to obtain a 30% xylene solution of organopolysiloxane. 80 from this solution
Xylene was distilled off at 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 permission chromatography revealed that the molecular weight in terms of styrene was about 10,000.

Synthesis Example 2 Phenyltrimethoxysilane
100 g, 180 g of methyltrimethoxysilane, ethyl silicate
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 the organopolysiloxane obtained after the water washing had a concentration of 35%. This was concentrated to a 50% solution as in Synthesis Example 1. The resulting organopolysiloxane has 5 silanol groups as functional groups.
%, 3% methoxy groups and 0.5% ethoxy groups. Analysis by gel permission chromatography showed a molecular weight in terms of styrene of about 7,000. The gel permission chromatograph in Synthesis Examples 1 and 2 was measured using HLC-802A (manufactured by Tosoh Corporation). The solvent was THF at a flow rate of 1.0 ml / min, and the temperature was 38 ° C.

[0020]

[0021]

Examples 1 to 3 are components A) shown in Table 1 (synthesis examples 1 and 2).
200g of the 50% solution obtained in the above) and fine powder of dry silica (trade name:
Erosil-300, manufactured by Nippon Aerosil Co., Ltd.)
After mixing well, mix the components (B) and
50 g of propyl alcohol was added and mixed to obtain a coating solution .
Glass cloth [Product name: WE18GT, Nitto Boseki Co., Ltd.]
After the γ- aminopropyltriethoxysilane as D) component of 1 m ² per 0.5g was sprayed in manufacturing, on the obtained silane-treated glass cloth obtained air dried for 1 hour at room temperature
After impregnating with the above coating solution, air-dry for 1 hour.
Precured for a minute to prepare a prepreg. This prepreg
And press for 1 hour at 180 ° C and 50kg / cm ²
It was cured to obtain a laminate.

Comparative Examples 1 to 3 The components A) shown in Table 1 , respectively (Synthesis Examples 1 and 2)
Example 2 using 200 g of the 50% solution obtained in step 2), without using the components B) and D) or using only the component D) shown in Table 1.
A coating liquid was prepared in the same manner as in Examples 1 to 3, and a silane-treated glass cloth was prepared in the same manner to prepare a laminate.

Example 4 A coating solution was prepared in the same manner as in Examples 1 to 3 , except that 200 g of the 50% solution obtained in Synthesis Example 1 was used as the component (A) and 0.5 g of Ce octylate was used as the component (B). . Glass cloth (WE
After spray-coating 0.5 g / m ² of γ-glycidoxypropyltrimethoxysilane as a component (D) on 18 GT), air-dried at room temperature for 1 hour to obtain a silane-treated glass cloth. In the same manner as described above, a laminate was prepared using the above-mentioned coating solution.

Comparative Example 4 200 g of the 50% solution obtained in Synthesis Example 1 was used as the component A).
A coating solution was prepared in the same manner as in Example 4 using 0.2 g of N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane as the D) component without using the B) component. A silane-treated glass cloth was prepared, and a laminate was prepared.

Examples 5 and 6, respectively, 200 g of the 50% solution obtained in Synthesis Example 1 as component A)
The, B) using octylate Ce0.5g as component, in Example 5 as a D) component of γ- glycidoxypropyltrimethoxysilane 0.5g, using the same silane 5.0g in Example 6, Example A coating solution was prepared in the same manner as in Examples 1 to 3 to prepare a laminate.

A heat resistance test was performed on the laminates obtained in the above Examples and Comparative Examples. The laminate was cut into a rectangle of 50 mm × 25 mm to obtain a test piece, and the change with time when heated in an electric furnace at 350 ° C. was followed by the change in bending strength and appearance. The results are shown in Table 1. The bending strength was measured by an autograph IM-100DS manufactured by Shimadzu Corporation. The appearance was evaluated as ○ for glossy, Δ for hardly glossy, and × for chalking, cracks or peeling between layers.

[0028]

[0029]

[0030]

[Table 1]

[0031]

According to the present invention, there is provided a silicone resin laminate excellent in heat resistance having a bending 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 better heat resistance than the conventional one, the effect of the present invention is extremely large.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-185442 (JP, A) JP-A-6-100781 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 C08L 83/04-83/08

Claims (4)

(57) [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, b is 0.01 The organopolysiloxane represented by the formula:
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, D) amino group-containing alkoxysilane, epoxy group Silane and / or a partially hydrolyzed condensate thereof selected from the group consisting of alkoxysilanes and partially hydrolyzed condensates thereof;
C) the substrate is coated or impregnated with the coating solution to which the
A laminate characterized by being formed. 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 The organopolysiloxane represented by the formula:
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, C) a silane and / or a partially hydrolyzed condensate thereof selected from the group consisting of alkoxysilanes containing epoxy groups, alkoxysilanes containing epoxy groups and partially hydrolyzed condensates thereof,
A laminate characterized by being applied or impregnated on a substrate applied at a rate of 0.1 to 1.0 g per 1 m ² and molded. 3. 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 The organopolysiloxane represented by the formula:
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, D) amino group-containing alkoxysilane, epoxy group Silane and / or a partially hydrolyzed condensate thereof selected from the group consisting of alkoxysilanes and partially hydrolyzed condensates thereof;
The coating solution was added parts by weight, per 1 m ² 0.1 to a D) in C) substrate
A laminated plate characterized by being applied or impregnated into a product coated at a rate of 1.0 g and molded. 4. The laminated board according to claim 1, wherein a bending strength reduction rate after heat treatment at 350 ° C. for 1,000 hours is 50% or less.