JPS5950182B2 - silicone resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel heat-curable silicone resin composition.

More specifically, number average molecular weight 9,000 to 10,00
0 methylpolysiloxane and ClCCH3)2Si0)
The present invention relates to a silicone resin composition comprising a novel block polymer synthesized from m(CH3)2SiCl. Generally, silicone resins are obtained by co-hydrolyzing diorganodichlorosilane and monoorganotrichlorosilane.

Therefore, the resulting resin has diorganosiloxane units and monoorganosiloxane units randomly distributed. As the number of diorganosiloxane units increases, the final cured resin becomes more flexible, but its heat resistance deteriorates, and before curing, the resin is sticky, fluid, and difficult to handle. Conversely, as the number of monoorganosiloxane units increases, heat resistance increases, but the resin becomes brittle. Therefore, it has been difficult to obtain a highly heat resistant and flexible resin using the above-mentioned cohydrolysis method. Therefore, the present inventors have conducted intensive research to develop a silicone resin that satisfies the above requirements, that is, has high heat resistance and flexibility, and as a result, has arrived at the present invention. That is, the present invention has a number average molecular weight of 9.0 as shown below.
00-10,000 methylpolysiloxane and CICC
H,)2Si0')m(CH,)2SiC1 and a curing catalyst are essential components, and if necessary, an inorganic filler and/or a heat-resistant pigment are blended. It is a silicone resin composition.

There are already known techniques for producing silicone block polymers from diorganosiloxane units and monoorganosiloxane units.

For example, in JP-A-49-93500, in a system consisting of water, acetone, and a water-immiscible organic solvent, diorganodichlorosilane is first hydrolyzed, and then monoorganochlorosilane is hydrolyzed to form organic groups and Si. The ratio is 1
．． 4 to 1.7, the resulting polymers are flexible and can be dried to a non-tacky, non-flowing state before curing. It has been stated. The patent also states that if the hydrolysis reaction is carried out in the order of monoorganotrichlorosilane and then diorganodichlorosilane, the resulting resin will be undesirably sticky. Furthermore, in U.S. Pat. No. 3,294,737, the following aryl silsesquioxane and YCR2"SiO) MRl'SiY (wherein R1' = alkyl group, aryl group, other, Y = halogen, hydroxyl group, m = 1 ~1000).On the other hand, the manufacturing method of the block polymer used in the silicone composition of the present invention is similar to that of the above-mentioned two known techniques, but it is manufactured using a monoorganic polymer. Number average molecular weight 9,000 as shown below as a siloxane unit
-10,000 methylpolysiloxane (self) is used without or after isolation from the reaction mixture.

That is, by using methylpolysiloxane (A), which has a relatively high molecular weight that has never been seen before, as a monoorganosiloxane unit, the ratio of organic groups to Si of the resulting polymer is 1.
．． By introducing diorganosiloxane units so that the number is 2 to 1.5, the polymer targeted by the present invention can be obtained. The polymer thus obtained is characterized by good heat resistance, a high ignition residual amount, and the cured product is flexible. One of the methods for producing block polymer 1, component (a), used in the present invention is to dissolve methyltrichlorosilane in a mixed solvent of ketone and ether in the presence of an amine, and then add water dropwise to perform hydrolytic polymerization. After producing methylpolysiloxane, diorganodichlorosilane is added to the system and further reacted.

Various types of amines from primary to tertiary, such as triethylamine, trinormalpropylamine, triisopropylamine, diethylamine, ethylamine, pyridine, and ethylenediamine, can be used as the amine to coexist, and triethylamine, diethylamine, etc. are particularly effective. .

As the ketone used in the hydrolytic polymerization reaction, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, etc. can be used, and as the ether, diethyl ether, tetrahydrofuran, diethylene glycol dimethyl ether, etc. can be used. Although any combination of these ketone and ether mixed solvents is possible, a mixed solvent of methyl isobutyl ketone and tetrahydrofuran is particularly effective. Next, the above manufacturing method will be described in detail.

First, the amine and then methyltrichlorosilane are dissolved in a mixed solvent of ketone and ether, and the amount of solvent used can be 5 to 10 parts by volume per 1 part by volume of the raw material methyltrichlorosilane. If it is less than 5 parts by volume, an insoluble resin will be produced, and if it is more than 10 parts by volume, the molecular weight of the resulting polymer will be low at a low monomer concentration.

Particularly preferably 7 to 8 parts by volume. The amount of ketone relative to ether can be 1 to 5 parts by volume per volume of ether, preferably 2 to 3 parts by volume. The amount of amine can be used up to nearly 3 times the mole of methyltrichlorosilane, but the preferred amount of amine (J) is equimolar to methyltrichlorosilane. Now, the ketone and ether layer in which the silane and amine have been dissolved is ice-cooled, and water is gradually added dropwise while stirring. A white precipitate of amine hydrochloride gradually forms, but as more water is added, it dissolves. The amount of water is sufficient to dissolve all of this hydrochloride. After the dropwise addition is completed, the reaction vessel is heated in an oil bath. The temperature of the oil bath can be arbitrarily selected up to 120°C, but when the temperature is low, it is necessary to heat for a long time. Preferably, the mixture is heated at around 110° C. for about 2 hours while the contents are gently refluxed. In this way, methylpolysiloxane having a number average molecular weight of 9,000 to 10,000 is produced. After that, the ratio of organic groups to Si of the polymer that produces diorganodichlorosilane is 1.2 to 1.5 (approximately 0.3 to 0.6 mol of diorganodichlorosilane per 1 mol of methyltriyuchlorosilane). Drip until it is. After the addition is complete, the mixture is heated for an additional 2 hours. After the reaction, the organic layer was washed with water until the water after washing became neutral, dried over anhydrous sodium sulfate, and concentrated. It is condensed and poured into methanol to obtain a polymer. Another method for producing the block polymer component (K) is to first produce methylpolysiloxane (^) by the method described above, except that the addition of diorganodichlorosilane is omitted.

Obtained methi. ClCCH3)2Si0]MSi(CH3
) A block polymer is obtained by reacting with 2CI1. The types of amines used here are 1
Almost all amines from grade to tertiary are included, but pyridine, triethylamine, etc. are particularly effective. As organic solvents, it is possible to use aromatic solvents such as benzene and toluene, haloalkane solvents such as dichloromethane and chloroform, ether solvents such as diethyl ether and tetrahydrofuran, and ketone solvents such as acetone and methyl isobutyl ketone. Tetrahydrofuran, methyl isobutyl ketone, etc. are effective. C.I.
CCH,)2Si0')MSi(CH3)2C11 is m
= 0 to 100 can be used, but especially m = 0 to 2
A value of about 0 gives preferable results.

To describe the quantitative relationship, taking pyridine as an example, the amount of amine is 0.1 per 1 part by weight of methylpolysiloxane (A).
~1 part by weight is possible, but about 0.5 part by weight is most preferred. Taking tetrahydrofuran as an example, the amount of solvent is 3
Although a range of 10 parts by weight is possible, a range of about 5.5 parts by weight gives preferable results. Cl[(CH3SiO')M
The optimal amount of Si(CH3)2C1 to be added differs depending on the number of m, but if m = 20, for example, it is 0.1 to 0.
．． 5 parts by weight can be used. Among these, the most preferred amount is about 0.2 to 0.3 parts by weight. To describe the manufacturing procedure, methylpolysiloxane^ is dissolved in a solvent, an amine is added, and ClCCH3)2Si0)MSi(CH3)2
Add C1 and react. The reaction temperature can be arbitrarily selected depending on the boiling point of the solvent, but the lower the temperature, the longer the reaction time needs to be. Preferably, the conditions are 50° C. for 20 hours. After the reaction is completed, the reactant is poured into methanol to obtain a polymer. The block polymer thus obtained was measured in solid form at 30° C. in THF.

is usually about 0.1 to 0.5, and its structure is composed of methylpolysiloxane units, that is, -:'L)]L)]
] It is estimated that the structure is expressed as follows.

The block polymer obtained by the above two production methods can be used as it is as a thermosetting resin composition by mixing it with a curing catalyst, or it can be further mixed with an inorganic filler or a heat-resistant pigment as described below. They can be blended to form molding and coating compositions.

Next, as the curing catalyst for component (b) used in the present invention, any conventionally known catalyst can be used.

Namely, organic amines such as ethanolamine, diethanolamine, ethylenediamine, triethylenediamine, and triethanolamine, lead compounds such as lead oxide, lead carbonate, lead stearate, and octyl lead, dibutyltin dilaurate, dibutyltin dimaleate, tin octylate, and naphthenic acid. Tin compounds such as tin and quaternary ammonium compounds such as tetramethylammonium hydromoside can be used. The inorganic fillers and heat-resistant pigments used as component (c) in the present invention are conventionally known ones, such as diatomaceous earth, clay, glass beads, magnesium silicate, zirconium silicate, and aluminum silicate. , alumina, magnesia, titania, glass fiber, asbestos fiber, carbon fiber, aluminum paste,
Examples include zinc powder. The usage ratio of each component in the composition of the present invention varies depending on the purpose, but for example, 0.3 to 2 parts by weight of component (1) to 100 parts by weight of component (A), and 60 parts by weight of component (C). It can be used in the following proportions by weight.

The silicone resin composition of the present invention is manufactured by a conventional method.

For example, (a) using a roll, kneader, or pen shell mixer heated above the softening point of the ingredients (b)
It can be obtained by mixing predetermined amounts of the components to (c), cooling and then pulverizing. In addition, component (a) is dissolved in a solvent such as acetone, tetrahydrofuran, toluene, xylene, etc., and component (c) is added to this to create a dispersion liquid.
The ingredients can be mixed to obtain a product suitable for use in paints. Alternatively, after spraying or impregnating glass fibers, carbon fibers, etc. with this mixed dispersion,
By evaporating the solvent, a product suitable for lamination molding and compression molding can be obtained. Conventionally known molding methods such as compression molding, transfer molding, injection molding, etc. can be used to mold the above molding material.

For example, in compression molding, the mold temperature is 150 to 200℃.
A pressure of 30 to 400 kg/D and a molding time of 5 to 30 minutes are appropriate, but after-curing at 200 to 250°C is required to obtain a product with excellent mechanical strength. The product obtained by molding in this manner has excellent mechanical strength and heat resistance. In the case of paints, the above-mentioned paint dispersion is applied to a suitable object (for example, a steel plate) and then heated at 140 to 160°C for 20 to 30 minutes to improve adhesion, weather resistance, and heat resistance. An excellent cured film can be obtained.

Example 1 Methyl isobutyl ketone (65 ml) and tetrahydrofuran (23a) were placed in a reactor equipped with a reflux condenser, a dropping load, and a stirring rod, and methyltrichlorosilane (12 ml, .0.1 mol) and triethylamine (14a) were added to the reactor.
, 0.1 mol).

Cool the reaction container on ice and add water dropwise to the container while stirring. A white precipitate of triethylamine hydrochloride gradually forms, but it dissolves again by adding more water.
Next, using an oil bath, the mixture is heated and refluxed at a temperature of 100 to 110°C for 2 hours. The number average molecular weight of the produced methylpolysiloxane was about 9,000. Thereafter, dimethyldichlorosilane (6.1d) was added dropwise and the mixture was further heated for 2 hours. After the reaction is completed, the organic layer is separated, washed with water until the washing water becomes neutral, and dried over anhydrous sodium sulfate. Thereafter, the drying agent is removed, the mixture is concentrated to a point where the polymer precipitates, and the mixture is poured into methanol to precipitate the polymer. The obtained precipitate is thoroughly washed with methanol and dried under vacuum. Yield 7.59, methyl groups to silicon was 1.4. The intrinsic viscosity of the obtained polymer was (4)=0.20 (THFl3O°C). Next, 100 parts of this polymer was dissolved in 280 parts of toluene, 0.3 parts of triethanolamine was added, and a heat-cleaned glass cloth was impregnated with this, followed by hot air drying to remove the toluene and form the molding material. Obtained.

Next, stack 15 sheets of the molding material obtained above and mold at a temperature of 16
After lamination molding was carried out for 15 minutes at 0° C. and a molding pressure of 100 kg/0 d, the mold was disassembled to obtain a molded product.

This material had no bulges or layer divisions, and had excellent physical properties as shown below. Bending strength (JISK69
ll); 15kg/d, dielectric breakdown voltage (JISK69
ll); 15KV/MllLO heat resistance; 300℃30
Although it was heated for a while, there was no change such as cracking or blistering.

Example 2 Methylpolysiloxane (4) is synthesized by omitting the addition of dimethyldichlorosilane in the synthesis method for block polymer 1 of Example 1.

This polymer (C7i) = 0.09, THF, 30°C)
After dissolving 409 in 225 g of tetrahydrofuran and adding pyridine 209, Cl[(CH3)2Si0
]20S1(CH,)2C139 was added and heated at 50℃ for 20
Allow time to react. The reaction mixture is poured into methanol to precipitate the polymer. The obtained polymer is thoroughly washed with methanol and then vacuum dried. The obtained polymer had a yield of 41
f! The intrinsic viscosity Ω was 0.45 (THF, 30° C.). Glass cloth was impregnated with the polymer obtained here in exactly the same manner as described in Example 1, and then laminated and molded to obtain a molded article.

Its physical properties were as follows. Bending strength: 14kf
! /C7ll, breakdown voltage; 13KV/! MO heat resistance: Although heated at 300°C for 3 hours, there were no changes such as layer splitting or blistering.

Comparative Example 1 A molded article was obtained in the same manner as described in Example 1 using a commercially available silicone resin.

Its physical properties were as follows. Bending strength 8-1
2kg/011 Dielectric breakdown voltage 10-14KV/Mm Heat resistance (heated at 300°C for 30 hours) Blistering and layer cracking were observed in some parts.

Example 3 The block polymer 59 obtained in Example 2 was diluted with 6.5 toluene.
Dissolve in 9.

This solution is applied to aluminum paste [manufactured by Tokai Metal Co., Ltd.]
Add gradually to Altop Φ13]1.59 to make an aluminum dispersion. Add to this 0.05 tin octylate! ! The mixture was applied to a steel plate that had been previously treated with sandpaper, and baked at 150°C for 30 minutes. Adhesion and heat resistance tests were conducted on the resulting coating film (film thickness: approximately 10 μm). The results are shown in the table below. Explanation of the cross-cut test; Use a knife to make cross-cut lines on the coating surface at 1n intervals vertically and horizontally (to create 100 squares of 1 m 1 L), paste zero tape on this and peel it off. If the adhesion is excellent, as indicated by the number of 1 ml squares remaining on the substrate, no peeling is observed.

When peeled off, the large number of remaining particles generally corresponds to good adhesion. Comparative Example 2 A paint was prepared using a commercially available silicone resin with the same formulation as in Example 3, and after coating and baking under the same conditions as in Example 3, the performance of the paint film was tested.

Claims (1)

[Claims] 1 (a) (i) A number average molecular weight of 9,000 to 9,000 as shown below.
10,000 methylpolysiloxane and ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (ii) Cl [(CH_3)_2SiO] m(CH_3
)_2SiCl (m=0 to 100 in the formula), and (b) a curing catalyst are essential components, and if necessary, (c) an inorganic filler and/or a heat resistant material. A silicone resin composition obtained by blending a pigment. 2. Claim 1, wherein the component (a) is a silicone block polymer obtained by adding (CH_3)_2SiCl_2 during the condensation reaction of methylpolysiloxane.
Compositions as described in Section. 3 The above component (a) has a number average molecular weight of 9,000 to 10,
000 methylpolysiloxane and ▲Mathematical formulas, chemical formulas, tables, etc.▼Cl[CH_3)_2SiO]m(CH_
3) The composition according to claim 1, which is a silicone block polymer obtained by reacting with _2SiCl (wherein m=0 to 20).