JPS5991603A - Thermal conductive electrically insulating material and method of producing same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel thermally conductive material having electrical insulation properties and a method for manufacturing the same.

Conventionally, mica plates, aluminum oxide, mylar plated polyethylene, terephthalate films), beryllium oxide, boron nitride, and the like have been used as thermally conductive materials that have electrical insulation properties. These materials lacked flexibility, causing breakage during processing) and causing dielectric breakdown. Furthermore, in order to improve contact, it was necessary to use heat dissipation grease. In response to this, recently a heat conductive material made by kneading boron nitride into silicone rubber has been developed as a heat conductive material that is flexible and has electrical insulation properties.

However, this material does not necessarily have sufficient properties and has the following problems. Namely: a) A large amount of inorganic filler is mixed, resulting in a decrease in flexibility. b) Because the polymer is two-dimensionally bonded, its mechanical strength is low and its elongation is low.

・) Electrical insulation cannot be improved. Engineering) Material costs are high.

In view of the above-mentioned problems with thermally conductive electrically insulating materials, the present inventors have worked on developing a new thermally conductive material that is electrically insulating and has good thermal conductivity, and have completed the present invention. be.

An object of the present invention is to provide a novel thermally conductive electrically insulating material and a manufacturing method that have thermally conductive properties and are superior in electrically insulating properties to conventional materials.

A thermally conductive electrical insulating material characterized by comprising a crosslinking agent and an inorganic filler of aluminum oxide or aluminum hydroxide, and a method for producing the same.

The thermally conductive electrical insulating material in the present invention does not consist of a polymer as a base material, an organometallic alkoxide crosslinking agent, and an inorganic filler, and the polymer is a thermoplastic material having 10H groups in its molecular chain. Resin e.g. polyvinyl alcohol polyvinyl butyral O
HC=o (C)h )z 1 00-CH-00H 1111 +CHr"CH-C&-CHCHr(IH-C&-CH
E-phenoxy resin is preferable, and as a crosslinking agent, an alkoxyl metal in which a metal is bonded to an alkoxyl group, which is a monovalent atomic group in which oxygen is bonded to the end of an alkyl group, particularly an organometallic alkoxide is used as a crosslinking agent. effective, ib, and organometallic alkoxides such as At(OR)s, T r (OR)4 e
Zr(OR)4 and Ge(OR)4 where R is C1 to C
4 -CH5-C2H5-Ca H7--Ca He
Alkyl groups and phenyl groups consisting of -CsHs, etc. can be opened. Specifically, At(OCR(CHs)2
)3-At(0C4Hs)s.

At(OCzHs)sw At(OC4Hs)sy
Ti(OCaHe)4sZ r (OC4He)4
etc. have been proven to be effective by the embodiments of the present invention. An inorganic filler is added to the product obtained by crosslinking these above-mentioned polymers with an organometallic alkoxide, and as the inorganic filler, aluminum oxide and aluminum hydroxide are preferable as the thermally conductive electrically insulating material of the present invention.

As for the component ratio of each component of the thermally conductive electrically insulating material according to the present invention described above, the polymer made of a thermoplastic resin having 10H groups in the molecular chain is 20% by weight in the thermally conductive electrically insulating material.
If the organometallic alkoxide used as a crosslinking agent is less than 1% (weight), crosslinking will be insufficient and sufficient strength will be obtained. Therefore, it is preferable to limit the amount to 1 to ioz.On the other hand, if the content of the inorganic filler is less than 50% by weight, sufficient thermal conductivity cannot be obtained, and if it exceeds 80% by weight, the reaction between the polymer and the organic metal will occur. The amount is preferably 50 to 80% by weight, since there is insufficient crosstalk with objects.

Further, the thermally conductive electrically insulating material of the present invention is prepared by adding a polymer such as polyvinyl alcohol, polyvinyl butyral, or phenoxy resin to a reaction vessel through which nitrogen gas is passed, in an amount equivalent to 20 to 49 inches (by weight) as a thermally conductive electrically insulating material. is heated and melted at 100-220°C depending on the properties of the polymer, and while stirring, an organometallic alkoxide such as Tf(OR)4- AL(OR) as G is added as a crosslinking agent.
1 to 10% (weight equivalent) of e(OR)n etc. is gradually added and reacted for 20 to 60 minutes. In this case, if more than 10 inches (by weight) is added, for example, about 15 inches (by weight), the reaction product becomes gelatinous due to excessive crosslinking, which is not preferable. Next, the reaction product is taken out from the reaction vessel, and the reaction product and the above-mentioned aluminum oxide or aluminum hydroxide are mixed at 50-80%.
Charge it into a normal mixer with an amount equivalent to 110~22% by weight.
The mixture is sufficiently kneaded at 0° C. for 10 to 20 minutes, and then molded into a sheet having a desired shape and appropriate thickness using a molding machine, such as a kaleider equipment, to produce a thermally conductive electrical insulating material.

The manufacturing method and characteristic values of the thermally conductive electrically insulating material of the present invention will be described below with reference to Examples.

Example 1 As a polymer, polyvinyl butyral (electrochemistry: Denka Butyral φ2000L) 30 weight 1 commercially available ALCOCH (CHs) g as organometallic alkoxide
) 3 and 65% by weight of aluminum hydroxide (Showa Light Metal Hisilite H-32I) as an inorganic filler.
After charging At(OCR(CH
s)+1)! ' (5% by weight) was gradually added and the reaction was carried out for about 30 minutes. Next, the reaction product was taken out and put into a pressure kneader (pressure 5~/cII) as an inorganic filler together with the above-mentioned Igilite H-32I (65 heavy duty), and mixed at 150°C% for 10 minutes. . After crosstalk, use calendar equipment (Japan Roll 141nch reverse type) to
．． A sheet with a thickness of 3 wm was prepared, and its characteristic values as a thermally conductive material were determined.

The results of the characteristic values are shown in Table 1.

Example 2 The polymer used as the base material was 25% by weight of polyvinyl alcohol (Shin-Etsu Chemical Poval C-17), 5% by weight of organometallic Toshite (DAL (OCa Hs) s t).
In addition, the Shin-Etsu Poval C-17 (25% by weight) was placed in a reaction vessel through which nitrogen gas was passed, as in Example 1, using a material consisting of 70% by weight of aluminum oxide (Showa Light Metal AL-13) as an inorganic filler. At(QC4Hs)s (5 weight Is
) was gradually added and the reaction was carried out for about 20 minutes, and then the reaction product together with the aluminum oxide (70% by weight) was charged into the same pressure kneader as in Example 1, and the mixture was mixed at 160°C for 10 minutes. A sheet was prepared in the same manner as in Example 1, and its characteristic values as a thermally conductive material were determined. The results are shown in Table 1.

Example 3 As the base polymer, phenoxy resin (manufactured by Union Carbide Co., USA) was used in an amount of 65% by weight and D, commercially available At(OCz Hs)s was used as an organic metal in an amount of 5% by weight, and the same as in Example 1 was used as the inorganic filler. 60 tons of the same aluminum oxide
The phenoxy resin (35 weight ts) was charged into the same reaction vessel as in Example 1 through which nitrogen gas was passed, melted by heating at 200°C, and while stirring, organic metal alkoxide kl (OCz Hs )s (5fold i'
%) and reacted for about 30 minutes, the reaction product together with aluminum oxide (60% by weight) was charged into the same pressure kneader as in Example 1, and heated at 200°C for 1
After 5 minutes of crosstalk, a sheet was prepared in the same manner as in Example 1, and its characteristic values as a thermally conductive material were determined. The results are shown in Table 1.

Example 4 Polyvinyl alcohol (Electrochemical Denka Poval K-17) 25 weight tons* as a polymer, Ti (OCa H9) 4 (Japan fada B-1) as an organometallic alkoxide
The polyvinyl alcohol (25% by weight) was mixed with a material consisting of 5% by weight and 70% by weight of aluminum hydroxide (Showa Light Metal AL-13) as an inorganic filler in a reaction vessel through which nitrogen gas was passed as in Example 1. 13
Organometallic T i (OC4HB
) 4 was gradually added in an amount equivalent to 5 parts by weight. After stirring for about 60 minutes, the reaction product was taken out and aluminum hydroxide (7
0% by weight) in the same pressure kneader as in Example 1, and cross-mixing was performed at 150° C. for 15 minutes. Example 1 after crosstalk
A sheet was prepared in the same manner as above, and its characteristic values as a thermally conductive material were determined. The results are shown in Table 1.

Example 5 The polymer was the same as in Example 1, with 60% by weight of polyvinyl butyral, and the organic metal was Zr COCa HB )4 (
Japan No. 1 TBZR') 5% by weight, and 65% by weight of aluminum oxide, the same as in Example 2, as an inorganic filler.
) was charged into a reaction vessel through which nitrogen gas was passed as in Example 1, and melted at 150°C.
HB)4 was gradually added in an amount of 5% by weight. After about 60 minutes of reaction, the product was taken out and placed in the same pressure kneader as in Example 1 together with 65% by weight of aluminum oxide and heated at 180°C.
After kneading for 5 minutes, a sheet was prepared in the same manner as in Example 1, and its characteristic values as a thermally conductive material were determined. The results are shown in Table 1.

Example 6 We plan to make a polymer with 15% by weight of polymer, 15% by weight of organic metal, and 70% by weight of inorganic filler.
Using the same polyvinyl alcohol as the organic metal, At(OCH(CHs)2)3 was gradually added dropwise to the material at a rate equivalent to 10% by weight over 10 minutes of pressure. After examining the reaction situation, a gel was formed. It was not possible to create a sheet.

Example Z It was planned to make a polymer with 15% by weight of polymer, 15% by weight of organic metal, and 20% by weight of inorganic filler.As the polymer, polyvinyl butyral, which was the same as in Example 1, was passed through the same spirit gas as in Example 1. Add 15% by weight of the material into a reaction vessel, melt at 160°C, and add At as an organic metal while stirring.
COC4Ha)s was gradually added dropwise to the mixture in an amount equivalent to 15% by weight of the material over a period of 10 minutes, and the reaction status was examined. As a result, gelation was observed at L7, making it impossible to prepare a sheet.

Example 8 It was planned to make a product similar to the composition of Example 6, so the same phenoxy resin as in Example 6 was put into a reaction vessel similar to Example 1, in which 155% of the weight was poured into a reaction vessel through which nitrogen gas was passed. While melting and stirring at °C, At(
QC2H5)3 was gradually added dropwise in an amount equivalent to 15% by weight over 15 minutes, and the reaction conditions were examined. As a result, it was found that the reaction mixture had turned into a gel, making it impossible to prepare a sheet.

The following Table 1 shows the characteristic values of the sheets as thermally conductive electrical insulating materials prepared in Examples 1 to 5 above and comparative values of the conventional material made by kneading boron nitride into silicone rubber.

Table 1 Characteristic Value Table As is clear from Table 1, the thermally conductive electrically insulating material of the present invention cross-links polymers with organic metals to form a three-dimensional network structure. It is an excellent material because it has improved physical strength and elongation, and can be made at a lower cost than silicone rubber boron nitride-based thermally conductive materials.

Agent: Patent Attorney Sanro Kimura

Claims (1)

[Claims] 1. A polymer comprising a thermoplastic resin having 10H groups in its molecular chain, an organometallic alkoxide crosslinking agent, and an inorganic filler of aluminum oxide or aluminum hydroxide. A thermally conductive electrical insulation material. 2. The thermally conductive electrically insulating material according to claim 1, wherein the polymer comprises polyvinyl alcohol, polyvinyl butyral, and phenoxy resin. 6. The organometallic alkoxide is At(OR)s e
Ti(OR)4- Zr(OR) as Ge(OR)
4, and in the molecular formula, OR is an alkyl group of 01 to C4 and a phenyl group, Claim 1
Thermally conductive electrically insulating material described in . 4. The polymer contains 20 to 490 to 49% by weight of 1
A thermally conductive electrically insulating material according to claim 1, characterized in that it consists of ~10% by weight and 50-80% of inorganic filler. 5. A type of polymer selected from polyvinyl, alcohol, polyvinyl butyral, phenoxy resin, etc. is heated and melted in a reaction vessel through which nitrogen gas is passed, and while stirring, At(OR)s-Ti(OR)4- Zr(OR)n-
Ge(OR)a However, R in the molecular formula is made by adding and reacting an organic metal consisting of a C1 to C4 alkyl group and an alkoxy metal which is a phenyl group, and kneading the reaction product and aluminum oxide or aluminum hydroxide together under pressure. A method for producing a thermally conductive electrically insulating material. 6. The reaction temperature between organometallic alkoxide and polymer is 1
The method for producing a thermally conductive electrically insulating material according to claim 5, characterized in that the temperature is 00 to 220°C and the kneading is carried out under pressure at 110 to 220°C.