JPS6017312B2 - silicone resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a silicone resin composition with excellent heat resistance.

More specifically, the present invention relates to a heat-resistant silicone resin composition prepared by mixing a methylpolysiloxane resin with an inorganic filler, a heat-resistant pigment, and a curing catalyst. Generally, molded products and paints obtained by blending various inorganic fillers or heat-resistant pigments with silicone resin are well known and have been put into practical use. However, many of the silicone resins currently used for these applications contain diorganosiloxane units, and their compositions have problems in terms of heat resistance. When it is not present, the resulting resin has a low molecular weight (in the case of MeSi◯, .5), so when it is made into a composition, there are problems with its physical properties at room temperature. Therefore, in order to improve these drawbacks, the present inventors created compositions using ladder-like methylpolysiloxane with a relatively high molecular weight and various inorganic fillers or heat-resistant pigments to solve this problem. , we have completed the present invention.

That is, the present invention aims to provide a silicone resin composition which eliminates the above-mentioned drawbacks, and which has a molecular weight of 9,000 to
100,000 ladder-like methylpolysiloxane, (
o} An inorganic filler and/or a heat-resistant pigment,
1) A curing catalyst.

The component [A] used in the present invention has a molecular weight of 9000 to 1 obtained by a hydrolysis single condensation reaction of C&SIC13.
00,000 of soluble ladder-like methylpolysiloxane.

Details of the method for producing such a ladder-like methylpolysiloxane can be found, for example, in Tokukan Sho 53-88 filed by the present applicant.
It is described in Publication No. 09y. Next, the inorganic filler and heat-resistant pigment of the raw component used in the present invention include those known in the art, such as diatomite, clay, glass beads, poppy, magnesium oxide, poppy, zirconium oxide, poppy , acid aluminum, alumina, magnesia, titania, glass fiber, asbestos fiber, force-bond fiber,
Examples include aluminum paste and zinc dust. Among these, aluminum paste is particularly preferred. As the one-component curing catalyst used in the present invention, any conventionally known catalyst can be used. i.e. ethanolamine,
Organic amines such as diethanolamine, ethylenediamine, triethylenediamine, and triethylamine; lead compounds such as lead oxide, lead carbonate, lead stearate, and octyl lead; and tin such as dibutyltin dilaurate, dibutyltin dimaleate, tin octylate, and tin naphthenate. compounds and quaternary ammonium compounds such as tetramethylammonium hydroxide, etc. can be used. The blending ratio of each component in the composition of the present invention varies depending on the purpose, but for example, for 100 parts by weight of component [A], (3 parts by weight of component o)
It can be used in a range of 0 to 60 parts by weight, and 0.3 to 2 parts by weight of the other component. The silicone resin composition of the present invention is manufactured by a conventional method.

For example, it can be obtained by mixing predetermined amounts of the above ingredients using a heated roll or a Henschel mixer, cooling and pulverizing the mixture. Alternatively, by dissolving component (i) in a solvent such as tetrahydrofuran, acetone, toluene, or xylene, and adding component (o) to this to create a dispersion, and mixing one component to this, a product suitable for paints can be obtained. Alternatively, you can spray this mixed dispersion onto glass fiber, carbon fiber cloth, mat, etc.
After impregnating the bond, if the solvent is evaporated, it can be used for laminated molding.
A material that has been passed through compression molding is obtained. The silicone resin composition of the present invention thus obtained can be molded by a conventionally known molding method.

For example, in compression molding, the mold temperature is 150 to 200 degrees.
A pressure of 50 to 400 k9/base and a molding time of 5 to 30 minutes are appropriate, but in order to obtain a product with excellent mechanical strength, an after cure at 200 to 250 k9 is required. The product obtained by molding in this manner has high mechanical strength and extremely high heat resistance. In addition, in the case of paint, after applying the above-mentioned paint dispersion to a suitable coating material (e.g. steel plate),
By heating at 6 pi for 20 to 30 minutes, a magnetized film with excellent adhesion, weather resistance, and heat resistance can be obtained.

As described above, according to the present invention, a silicone resin composition can be obtained that has properties not found in conventional silicone resins, particularly excellent heat resistance and mechanical properties.

Example 1 Methylpolysiloxane (number average molecular weight approximately 9000) 10
Dissolve the base with toluene 13'.

This solution was gradually added to aluminum paste [manufactured by Tokai Kinzoku ■, Altop #13] to prepare an aluminum dispersion. This dispersion, to which 1 part of tin octylate was added, was applied to a steel plate that had been previously treated with sandpaper, and subjected to mock bonding at 150° C. for 30 minutes. The resulting coating film (
Adhesion and heat resistance tests were conducted on a film with a thickness of approximately 10 mm. The results are shown in Table 1. Table 1 Paint film performance Explanation of the cross-cut test: Use a knife to cut lines on the square paint surface of a one-sided IQ kite in a cross-cut pattern at intervals of one rib in the vertical and horizontal directions. Attach sellotape to the board, peel it off, and indicate the number of squares of one fence remaining on the board.

If the adhesion is excellent, no peeling will be observed. When peeled off, the large number of remaining particles generally corresponds to good adhesion. Comparative Example 1 Commercially available silicone varnish (manufactured by Torre Silicone, S
A paint was prepared using the same formulation as in Example 1 using H994), and after coating under the same conditions as in Example 1, the performance of the paint film was tested.

The results are shown in Table 1. Example 2 Methylpolysiloxane (
10 parts (number average molecular weight: approx. 9000), 30 parts of diatomaceous acid that had been thoroughly dried in advance, 0.5 parts of stearic acid, and 1.5 parts of triethanolamine were dissolved and dispersed in 20 parts of toluene, and this was heated. After impregnating a cleaned glass cloth, toluene was removed by hot air drying to obtain a molding material.

Next, the molding material obtained above was layered 18 times, and the molding temperature was 16 times.
After lamination molding was carried out for 15 minutes at 0qo and a molding pressure of 100k9', the mold was dismantled to obtain a molded product. This material had no bulges or layer divisions, and had excellent physical properties as shown below. Bending strength 18k9/en (JI
SK6911) Dielectric breakdown strength 17KV/side (JISK
6911) Heat resistance No change such as blistering or layer splitting after heating for 300cm and 3G hours.

Comparative Example 2 Commercially available silicone varnish (manufactured by Torre Silicone, S
H994) and the same formulation as in Example 2 to prepare a dispersion.

After processing this under the same conditions as in Example 1, a molded article was obtained. The physical properties were as shown below. Bending strength 8-12
k9/block breakdown voltage 10 to 1 cycle V' Wind heat resistance After heating at 300°C for 3 hours, blistering and layer cracking were observed in some parts.

Example 3 A paint was prepared using methylbolysiloxane (number average molecular weight approximately 40,000) in the same formulation as in Example 1, applied under the same conditions as in Example 1, and after dawning, the performance of the paint film was tested.

The results are shown in Table 1. Example 4 A coating material was prepared using methylpolysiloxane (number average molecular weight approximately 95,000) in the same formulation as in Example 1, and after coating and competition under the same conditions as in Example 1, the performance of the coating film was tested.

Claims (1)

[Scope of Claims] 1 (a) Methylpolysiloxane of the following formula having a ladder-like structure with a number average molecular weight of 9,000 to 100,000, and (b) an inorganic filler and/or heat resistant sexual pigment,
(c) A silicone resin composition comprising a curing catalyst. 2. The heat-resistant silicone resin composition according to claim 1, wherein the component (b) is an aluminum paste.