US-12617940-B2 - Curable composition and cured material

Abstract

A curable composition and a cured material containing: a compound (A) having one (meth)acrylate group in one molecule; a compound (B) having two or more (meth)acrylate groups in one molecule; a polymerization initiator (C); a dispersant (D); and a thermally conductive filler (E) containing zinc oxide.

Inventors

• Ryuji Terauchi
• Yusuke Kato
• Masaaki Kondo
• Takuya Goto

Assignees

• COSMO OIL LUBRICANTS CO., LTD.

Dates

Publication Date

20260505

Application Date

20200108

Priority Date

20190115

Claims (9)

1. 1 . A curable composition, comprising: a compound (A) having one (meth)acrylate group in one molecule; a compound (B) having two or more (meth)acrylate groups in one molecule; a polymerization initiator (C); a dispersant (D); and a thermally conductive filler (E) containing magnesium oxide, wherein the dispersant (D) comprises at least one compound selected from the group consisting of a polyglycerin monoalkyl ether compound, a compound having a carboxy group, and a metallic soap, wherein a content of the dispersant (D) is from 1.5 parts by mass to 3 parts by mass with respect to 100 parts by mass of the compound (A), wherein the thermally conductive filler (E) further contains zinc oxide, wherein when the thermally conductive filler (E) contains a compound other than the magnesium oxide and the zinc oxide, the content of the compound other than the magnesium oxide and the zinc oxide is 10% by mass or less relative to the total mass of the thermally conductive filler (E), wherein a content of the magnesium oxide with respect to a total mass of the thermally conductive filler (E) is from 10% by mass to 70% by mass.
2. 2 . The curable composition according to claim 1 , wherein the compound (A) comprises a compound represented by the following general formula (1): wherein, in the general formula (1), R 1 represents an alkyl group having from 10 to 50 carbon atoms, and R 2 represents a hydrogen atom or a methyl group.
3. 3 . The curable composition according to claim 1 , wherein the compound (B) comprises a compound represented by the following general formula (2): wherein, in the general formula (2), R B1 represents an alkylene group having from 1 to 5 carbon atoms, each of R B2 and R B3 independently represents a hydrogen atom or a methyl group, and n is an integer of 4 or more.
4. 4 . The curable composition according to claim 1 , further comprising a plasticizer (F).
5. 5 . The curable composition according to claim 4 , wherein the plasticizer (F) comprises an acrylic polymer having a glass transition temperature of −20° C. or lower.
6. 6 . The curable composition of claim 4 , wherein the plasticizer (F) comprises a trimellitic acid ester.
7. 7 . The curable composition according to claim 1 , wherein a content of the compound (B) is from 0.5 parts by mass to 10 parts by mass with respect to 100 parts by mass of the compound (A).
8. 8 . The curable composition according to claim 1 , wherein a content of the thermally conductive filler (E) is from 70% by mass to 98% by mass with respect to a total mass of the curable composition.
9. 9 . A cured material, comprising the curable composition according to claim 1 after curing.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a National Stage Application under 35 U.S.C. 371 of co-pending PCT application number PCT/JP2020/000307 designating the United States and filed Jan. 8, 2020, which claims the benefit of JP application number 2019-004626 and filed Jan. 15, 2019 and JP application number 2019-167701 and filed Sep. 13, 2019, each of which are hereby incorporated by reference in their entireties. TECHNICAL FIELD The present disclosure relates to a curable composition and a cured material. BACKGROUND ART In recent years, due to significant performance improvement in arithmetic elements and light-emitting elements, there has been significant improvement in performance of electronic devices such as personal computers, mobile phones, and personal digital assistants (PDAs) and lighting and display devices such as light-emitting diodes (LEDs) and electronic luminescent (EL) devices. The performance improvement in arithmetic elements and light-emitting elements causes a marked increase in heating value, and how to dissipate heat in electronic devices and in lighting and display devices is a key challenge. To transmit heat generated by an arithmetic element or a light-emitting element to a heat radiator without loss and to dissipate the heat through the heat radiator, a thermal interface material (TIM) is disposed between a heat generator and the heat radiator as a measure for the heating. Known examples of the heat radiator include heat sinks, and known examples of the heat generator include central processing units (CPUs) and large-scale integrations (LSIs). In regard to the TIM, typically used examples include heat dissipation sheets, thermally conductive greases, and gap fillers. Among these examples, gap fillers are standing out because of the following property. That is, gap fillers are liquid during the early stage, and after application, gap fillers are cured and changed into a solid. As a gap filler obtained by filling a thermally conductive filler into a silicone resin, for example, Japanese Patent Application Laid-Open (JP-A) No. 2006-96986 discloses a hydrosilylation-curable thermally conductive silicone elastomer composition containing a hydrosilylation-curable organopolysiloxane composition, a reinforcing silica fine powder, a thermally conductive inorganic powder, and an alkylphenyl polysiloxane which is liquid at normal temperature. As the gap filler, for example, International Publication No. 2014/080931 discloses a heat dissipation structure including: (A) a printed circuit board; (B) a heat generator; (C) an electromagnetic shield case; (D) a rubbery thermally conductive resin layer having tensile elasticity of 50 MPa or less and thermal conductivity of 0.5 W/mK or more; and (E) a thermally nonconductive layer having thermal conductivity of less than 0.5 W/mK. The structure is characterized in that the heat generator (B) is disposed on the printed circuit board (A) and that the structure is provided with the heat generator (B) and the thermally conductive resin layer (D). For example, Japanese Patent No. 5105134 discloses a thermally conductive composition containing components (A) to (C), in which the component (B) is contained in an amount of from 0.01 to 10% by weight with respect to the component (A), the component (C) is contained in an amount of from 50 to 97% by weight with respect to the entire composition, and a thermal polymerization initiator is not contained. (A) Component: Compound containing one or more (meth)acrylate groups and one or more isocyanate groups in one molecule(B) Component: Photopolymerization initiator(C) Component: Thermally conductive filler For example, Japanese Patent Application Laid-Open (JP-A) 2005-48124 discloses a resin composition for a heat dissipation material, including a liquid resin containing a (meth)acrylic polymer (A), a polymerizable monomer (B), and a plasticizer (C) as essential components. A cured material of the liquid resin has hardness of from 5 to 70. SUMMARY OF INVENTION Technical Problem A silicone-based resin contained in the thermally conductive silicone elastomer disclosed in JP-A No. 2006-96986 remains concerned about a contact failure of an electronic component due to a low-molecular-weight siloxane component or the like and about an outflow of the silicone-based resin to the outside of the system over extended periods of use. TIMs play a role in transferring heat of heat generating components. Therefore, TIMs change in temperature along with temperature changes of surrounding components. This is why TIMs are required not to decrease in thermal conductivity when TIMs change in temperature while being sandwiched between components. In addition, substances increase in volume or the like along with temperature increase, but the coefficient (coefficient of linear expansion) varies depending on materials, which causes dimensional mismatch between components and causes a stress to members. When a temper