JPS60188441A - Heat-conductive material - Google Patents

Abstract

PURPOSE:The titled flame-retarding material excellent in electrical insulation, heat dissipation, processability, and adhesion, comprising chlorinated PE, a specified polymer, a filler, and other additives. CONSTITUTION:The titled material having a synthetic resin component content of 15-40wt% is obtained by kneading (A) 15-25wt% chlorinated PE of a chlorine content of 30-50wt% with (B) 3-15wt% at least one member selected from the group consisting of (a) an ethylene/vinyl acetate copolymer of a vinyl acetate component content of 5-50wt%, (b) a thermoplastic elastomer compatible with component A and having both of a rubbery soft segment and a resinous hard segment at room temperature, and (c) high-density PE of a density >=0.95g/ cm<3>, (C) 50-80wt% filler such as Al2O3, and (D) additives such as 0.1-2wt% coupling agent, 0.1-2wt% antioxidant, 0.5-2wt% stabilizer, 0.5-2wt% flame retardant, and 1-4wt% lubricant.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides electronic components that have both electrical insulation and heat dissipation properties, are easy to process, and do not require the use of other adhesion aids (grease, etc.). The present invention relates to a thermally conductive material that can improve adhesion to a heat sink or the like.

[Technical background]

Electrical and electronic components such as thyristors, power transistors, and diodes deteriorate in various characteristics as the temperature rises due to the heat generated when electrical (child) devices incorporating these devices are operated, and sometimes the components themselves are damaged. Sometimes.

In order to eliminate such problems, it is necessary to bond electronic and electronic components to a heat radiating body such as a heat radiating fin to prevent heat dissipation and to suppress the rise in temperature of the component itself.

Since heat sinks used for this purpose are generally metal, it is not possible to ensure insulation between them and electrical or electronic components. , polyester sheets, thermal grease, etc. were often used.

However, these materials have the following problems/ba.

■ Mica has poor processability and is difficult to handle ■ Polyester sheets have poor heat dissipation properties ■ Thermal greases lose oil when used for long periods of time, reducing their heat dissipation effectiveness ■ Polyester sheets, thermal greases, etc. are not flame retardant. ■ Mica and polyester sheets require the use of grease to improve the adhesion between the parts and the heat sink.

[Purpose of the invention]

In view of the above-mentioned circumstances, the present invention has excellent electrical insulation and heat dissipation properties, has good workability, and improves adhesion to the heat dissipation body without using grease. The present invention provides a thermally conductive material that also has flame retardancy.

[Summary of the invention]

The present invention was achieved as a result of various studies to obtain a material that achieves the above-mentioned objectives.

That is, the present invention comprises a) chlorinated polyethylene, b) one type of polymer selected from among ethylene-vinyl acetate copolymer, thermoplastic nidistomer, and high-density polyethylene, C2 filler, d, and other additives. A first invention is a thermally conductive material characterized by containing the following, and the first invention is characterized in that the polymer of component b is both an ethylene-vinyl acetate copolymer and a thermoplastic elastomer. and a second invention.

The chlorinated polyethylene used in the present invention has a chlorine content of approximately 30 to 50% by weight. When the chlorine content is less than 30% by weight, the flame resistance begins to decrease, and on the other hand, when it exceeds 50% by weight, the chlorine becomes unstable, which is undesirable.Chlorinated polyethylene containing such specific chlorine has poor thermal conductivity. It is blended into the material in an amount of approximately 15 to 25% by weight. If the amount of chlorinated polyethylene in the polymer matrix (commonly referred to as the matrix formed from all the polymers in the thermally conductive material, including the amount of the polymer described below) is too large, it will be difficult to process. appears, which is not desirable.

In addition to the above-mentioned polymer components, ethylene-vinyl acetate copolymer, thermoplastic elastomer, and high-density polyethylene are used. The ethylene-vinyl acetate copolymer preferably has a vinyl acetate component of about 5 to 50 parts by weight. If the amount is outside this range, for example, less than 5% by weight, the final product will lack flexibility, while if it exceeds 50% by weight, it will tend to become more sticky, which is unfavorable in terms of molding.

A thermoplastic elastomer has both a rubber-like soft segment and a resin-like hard segment at room temperature, and an olefin polymer is used from the viewpoint of compatibility with other polymer components such as chlorinated polyethylene.

Also, high density polyethylene has a density of approximately 0.95g/
, 4 or more are synonymous.

In the present invention, in addition to the above-mentioned polymer components, 50 to 80% by weight of filler is used. As fillers suitable for the purpose of the present invention, for example, aluminum oxide and aluminum hydroxide may be used alone or in the form of a mixture if necessary.

The filler used here greatly affects the heat dissipation characteristics, and if the amount used is less than 50% by weight, the thermal conductivity will decrease, which is not preferable. -10,000, the amount added is 80% by weight
If it exceeds this value, not only problems are likely to occur in terms of molding processability, but also the impact strength of the molded product decreases significantly and it becomes brittle.

In addition, in the thermally conductive material of the present invention, a coupling agent of about 0.1 to 2.0% by weight is used for the purpose of improving the water resistance of the constituent materials. As a coupling agent, γ-gly/doxopropyltrimethoxy γ-methacryloxypropyltrimethoxysilane (CH2=C (mount C) CO
Silane coupling agents represented by OCm Ha St COCHs )m ) and dihydroxybis(lactato)titanium (T l (CHz ) C0CI((CHs
) COOEL] 2) I-zoloboxytitanium tree 1
- stearate ((CHs)t HCO'rt (st
)s) A titanium coupling agent represented by:

In addition, about 0.1 to 2% by weight of an antioxidant is added and used, especially to prevent oxidative deterioration of the ethylene-vinyl acetate copolymer and thermoplastic nidistomer.

For this purpose, e.g. 3,5-sheeter
t,-butylanilino)-1,3,5-)riazine is used.

In addition, about 1.5 to 2% by weight of lead monoxide,
Lead-based compounds such as tribasic lead sulfate and epoxy resins such as bisphenol A glycidyl ether are used as stabilizers to improve the thermal stability of chlorinated polyethylene.
Approximately 2% by weight of at least one selected from hexabromobenzene (HBB), antimony trioxide (SB, OS), decabromodiphenyl oxide (DBDO), etc. as a flame retardant, and approximately 1 to 4% by weight At least one selected from the group of n-lead therate, barium stearate, polyethylene wax, and a mixture of natural wax and stearate is used as the lubricant.

[Embodiments of the invention]

Approximately 15% of
The mixture was kneaded for a minute, and then sheets were prepared using a calender.

In the table, each material is as follows.

Daisolac: Made by Osaka Soda Chlorinated polyethylene elasthrene: Made by Showa Denko Evatate: Made by Sumitomo Chemical Ethylene-vinyl acetate copolymer TPE: Made by Sumitomo Chemical Thermoplastic elastomer 4
250H: Made by Showa Denko High-density polyethylene Hi-Sex: Made by Mitsui Petrochemicals Hisilite: Made by Showa Light Metal Aluminum hydroxide AL-13: Made by Showa Denko Aluminum oxide KBM: Made by Shin-Etsu Silicon Silane coupling agent 'I'T8: Made by organic titanate Titanium coupling agent Chiratsuku ° 〃 〃 Irganox: Made by Ciba Antioxidant AFR:
Asahi Glass flame retardant AX-4T: Yoken Fine Chimical lubricant PA5
20: Polyethylene wax Epicoat 828 manufactured by Hoechst: Epoxy resin stabilizer manufactured by Shell
TS), elongation (E), thermal conductivity (λ), volume resistivity (ρ
v), breakdown voltage (BD), flame retardancy test (UL-94
) was measured and the following results were obtained.

〔Effect of the invention〕

The thermally conductive material obtained according to the present invention is more flexible than mica, which has been widely used in the past, and there is no risk of leakage even when used continuously for a long time like conventional thermal grease. Its thermal conductivity is superior to mica and polyester sheets.

In addition, this material meets the UL-94 flame retardant standard and exhibits properties equivalent to V-O, and due to its composition, this material has good adhesion to parts, so there is no need to use thermal grease. It is advantageous.

Agent: Patent Attorney Sanro Kimura

Claims (9)

[Claims] (1) a, chlorinated polyethylene, b, one selected from ethylene-vinyl acetate copolymer, thermoplastic nidistomer, and high-density polyethylene, C2 filler, d,
A thermally conductive material characterized by containing other additives. (2) The thermally conductive material according to claim 1, which uses chlorinated polyethylene having a chlorine content of 60 to 50% by weight. (3) 15 to 25% by weight as a component of the thermally conductive material
The thermally conductive material according to claim 1, wherein the material is chlorinated polyethylene. (4) Claim 1 consisting of the blending amount of component b, which is a component of the thermally conductive material, being 6 to 15% by weight.
Thermally conductive materials described in Section 1. (5) The total amount of heat conductive material biosynthetic resin components is 15 to 40
% by weight of the thermally conductive material according to claim 1. (6) The thermally conductive material according to claim 1, wherein an ethylene-vinyl acetate copolymer having a vinyl acetate content of 5 to 50% by weight is used as component b. (7) The thermally conductive material according to claim 1, which contains 50 to 80% by weight of a filler as component c. (8) A thermally conductive material containing a, chlorinated polyethylene, BL, an ethylene-vinyl acetate copolymer, a thermoplastic elastomer, a C1 filler, and d, other additives. (9) The thermally conductive material according to claim 8, which uses chlorinated polyethylene having a chlorine content of 6D to 50% by weight. 01 15-25% by weight as components of thermally conductive material
The thermally conductive material according to claim 8, comprising chlorinated polyethylene and [7]. 0η The thermally conductive material according to claim 8, wherein the amount of component b, which is a component of the thermally conductive material, is 5 to 15% by weight. 0) The total amount of synthetic resin components in the thermally conductive material is 15 to 40
The thermally conductive material according to claim 8, which contains 1 t% by weight. Q.3 The heat conductive material (1) according to claim 8, wherein an ethylene-vinyl acetate copolymer having a total vinyl acetate content of 5 to 5% by weight is used as the component b. 64. The thermally conductive material according to claim 8, which contains 50 to 80% by weight of a filler as component C.