Copolymer compound and resin composition

Abstract

A copolymer compound having a structure represented by formula (1). (In formula (1), X1-X3 are each independently a trivalent organic group, Y1-Y3 are each independently a divalent organic group, Z1 is a monovalent organic group, Z2 is a hydrogen atom or a monovalent organic group, each R is independently a monovalent organic group, W is a divalent organic group, with at least one carbon-carbon double bond or triple bond being included, k is a number of 16-33, n, m, o, r, and s, are each a number of 1 of more, and p and q are each a number of 0 or more.)

Description

Copolymer compounds, resin compositions

[0001] The present invention relates to a copolymer compound and a resin composition containing the copolymer compound.

[0002] In recent years, with the miniaturization and high performance of electrical devices, there has been a demand for material technologies that can efficiently dissipate the heat generated during operation.Heat from heat sources such as IC chips is dissipated through heat sinks, and to ensure efficient thermal conduction between the heat source and the heat sink, a resin composition called a TIM (Thermal Interface Material) is often sandwiched between the heat source and the heat sink.

[0003] TIMs are resin compositions that combine resin and thermally conductive fillers, and are often used in sheet form with a thickness corresponding to the gap between the heat source and the heat sink. In recent years, highly compressible sheets have been required to broaden the TIM's tolerance range for gap assembly tolerances. Furthermore, high compression loads can cause chip damage, so flexible sheets are required. On the other hand, imparting flexibility to sheets tends to worsen their handling. To resolve this trade-off between compressibility and handling, resin compositions containing a matrix such as a silicone resin, a phase change material (PCM), and a thermally conductive filler have been proposed.

[0004] For example, Patent Document 1 discloses an invention relating to a thermally conductive film that is easy to handle in a film form at room temperature and softens when heated, and that contains a specific non-flowable silicone resin, a wax with a melting point of 20 to 60°C, and a thermally conductive filler in predetermined amounts. Patent Document 2 discloses an invention relating to a composition that can be used as a thermal interface material for electronic devices, and that contains a base material containing 4 to 60% by weight of a silicone resin and 0 to 35% by weight of a silicone polymer, 40 to 96% by weight of a thermally conductive filler, 0 to 5% by weight of a treatment agent, and 0 to 1% by weight of an antioxidant.

[0005] Patent Document 3 discloses an invention relating to a thermal countermeasure component that absorbs and transfers heat generated by heat sources such as electronic components to prevent overheating of the heat source, and that is made by coating a silicone elastomer filled with paraffin wax powder having a particle size of 250 μm or less and a thermally conductive filler having an average particle size of 30 μm or less with a coating material. Patent Document 4 discloses an invention relating to a heat-softening, thermally conductive silicone grease composition that is used on the thermal interface between a heat-generating electronic component and a heat-dissipating component such as a heat sink or metal housing, and that contains a silicone wax having a melting point of 30 to 80°C, a specific organopolysiloxane, and a thermally conductive filler in specified amounts.

[0006] Patent Document 5 discloses an invention relating to a heat-dissipating sheet that softens when heated, provides good adhesion between a heat-generating element and a heat sink, and has excellent thermal performance. The heat-dissipating sheet includes a polymer gel such as silicone gel, a compound that is solid or paste-like at room temperature but becomes liquid when heated, and a thermally conductive filler. Patent Document 6 describes a thermal interface material that undergoes a phase change at the operating temperature of a microprocessor and transfers heat generated by a heat source to a heat sink. The thermal interface material includes a phase-change substance that softens near the operating temperature of the heat source, a polymer component, a substance that changes the softening temperature of the phase-change substance, and a thermally conductive filler. Patent Document 7 discloses an invention relating to a thermally conductive sheet that includes a binder component that is a mixture of a silicone matrix and a hydrocarbon compound, and a thermally conductive filler, has a compressibility of 15% or more at 80°C and 0.276 MPa, and has shape retention. The invention also describes that the thermally conductive sheet maintains a certain degree of flexibility during use, providing good thermal conductivity, while also having good shape retention and reliability.

[0007] Japanese Patent Publication No. 2023-47991 Japanese Patent No. 4954475 Japanese Patent Publication No. 2012-102264 Japanese Patent No. 6436035 Japanese Patent No. 3712943 Japanese Patent Publication No. 2001-89756 International Publication No. 2022 / 070568

[0008] Meanwhile, sheets made of TIM are also required to have reworkability to improve yield during assembly. However, the phase change materials used in conventional TIMs are poorly compatible with the matrix, especially silicone resins, which reduces the toughness of the TIM, making the sheet more susceptible to tearing when peeled from the adherend, resulting in poor reworkability, such as leaving part of the sheet on the adherend. Furthermore, sheets made of TIM are also required to have better room temperature handling properties and high-temperature compressibility.

[0009] Therefore, an object of the present invention is to provide a copolymer compound that, when added to a resin composition, satisfies handleability at room temperature, high-temperature compressibility, and reworkability. In another aspect, an object of the present invention is to provide a thermally conductive material that is excellent in handleability at room temperature and high-temperature compressibility.

[0010] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by a copolymer compound in which a long-chain organic group, an organic group having a silicone skeleton, and an organic group having a carbon-carbon unsaturated bond are bonded to side chains. Furthermore, as a result of extensive research, the present inventors have found that, in a thermally conductive material containing polyorganosiloxane, a heat-softening compound, and a thermally conductive filler, a T2 relaxation curve obtained by analyzing the pulse NMR T2 relaxation curve measured by the solid echo method at 10°C can be obtained. １ The inventors have found that the problems in another aspect can be solved by ensuring that the ratio of is equal to or greater than a certain level. That is, the present invention provides the following [1] to

[14] .

[0011] [1] A copolymer compound having a structure represented by the following formula (1): (In formula (1), X １ ~X ３ are each independently a trivalent organic group, and Y １ ~Y ３ are each independently a divalent organic group, Z １ is a monovalent organic group, and Z ２is a hydrogen atom or a monovalent organic group, each R is independently a monovalent organic group, W is a divalent organic group containing one or more carbon-carbon double bonds or triple bonds, k is a number of 16 or more and 33 or less, n, m, o, r, and s are each a number of 1 or more, and p and q are each a number of 0 or more) [2] The copolymer compound according to [1], wherein W contains one or more vinylidene groups or vinylene groups. [3] The copolymer compound according to [1], wherein X １ ~X ３ is a hydrocarbon group having 2 to 3 carbon atoms. １ ~Y ３ contains an ester group or an amide group. [5] The copolymer compound according to any one of [1] to [4], wherein m, n, and o satisfy the relationship of the following formula (α): m / (n+m+o)≧0.025 Formula (α) [6] The copolymer compound according to any one of [1] to [5], wherein m, n, o, and r satisfy the relationship of the following formula (β): o*r / (n+m+o)≧1.00 Formula (β) [7] Z ２is a monovalent organic group. [8] A resin composition comprising the copolymer compound according to any one of [1] to [7], a polyorganosiloxane having a hydrogen atom directly bonded to a silicon atom in its molecular skeleton, a catalyst, and a thermally conductive filler. [9] The resin composition according to [8], further comprising a polyorganosiloxane having a carbon-carbon double bond in its molecular skeleton.

[10] The resin composition according to [8] or [9], wherein the thermally conductive filler is at least one selected from the group consisting of metals, inorganic hydroxides, inorganic oxides, inorganic nitrides, carbon fiber, graphite, and diamond.

[11] The resin composition according to any one of [8] to

[10] , wherein the content of the copolymer compound is 10 parts by mass or more per 100 parts by mass of the polyorganosiloxane (X) contained in the resin composition.

[12] A thermally conductive sheet comprising a cured product of the resin composition according to any one of [8] to

[11] , wherein the thickness of the thermally conductive sheet is 0.05 mm or more and 5 mm or less.

[13] The thermally conductive sheet according to

[12] , wherein at least one of the thermally conductive fillers has an anisotropic shape, and the thermally conductive filler having an anisotropic shape is oriented within the thermally conductive sheet.

[14] A thermally conductive material comprising a polyorganosiloxane, a thermally softening compound, and a thermally conductive filler, wherein the T2 relaxation curve of the pulsed NMR measured by a solid echo method at 10°C for the thermally conductive material is analyzed by least-squares fitting using a function represented by the following equation (12), and the obtained a １ A thermally conductive material having a ratio of 10% or more. (In formula (12), a １ , a ２ , and a ３ is a １ +a ２ +a ３ = 100%, and t １ , t ２ , and t ３ are the T2 relaxation times of the respective relaxation components, t1<t2<t3, and x is the observation time in the pulsed NMR relaxation measurement.

[0012] According to the present invention, it is possible to provide a copolymer compound that, when added to a resin composition, satisfies handleability at room temperature, high-temperature compressibility, and reworkability. In another aspect of the present invention, it is also possible to provide a thermally conductive material that is excellent in handleability at room temperature and high-temperature compressibility.

[0013] FIG. 2 is a diagram illustrating a measuring device for measuring thermal resistance.

[0014] [Copolymer Compound] The copolymer compound of the present invention has a structure represented by the following formula (1). (In formula (1), X １ ~X ３ are each independently a trivalent organic group, and Y １ ~Y ３ are each independently a divalent organic group, Z １ is a monovalent organic group, and Z ２ is a hydrogen atom or a monovalent organic group, each R is independently a monovalent organic group, W is a divalent organic group containing one or more carbon-carbon double or triple bonds, k is a number between 16 and 33, n, m, o, r, and s are each numbers of 1 or greater, and p and q are each numbers of 0 or greater.

[0015] When blended into a resin composition, the copolymer compound of the present invention functions as a phase change material, improving the handleability of the resin composition at room temperature (25°C) while increasing compressibility at high temperatures (e.g., 60°C). Furthermore, by having the specific structure represented by formula (1), the copolymer compound of the present invention can improve the reworkability of the resin composition, preventing the composition from tearing when, for example, a resin composition molded into a sheet shape is peeled off from an adherend. In addition, the amount of bleeding is small, resulting in high reliability.

[0016] The copolymer compound is X １ ~X ３The main chain is constituted by the formula (I), and the copolymer compound has a moiety having a long-chain alkyl group as a branched chain, a moiety having a carbon-carbon double bond or triple bond (hereinafter also referred to as an "unsaturated carbon bond"), and a moiety having a silicone chain. The copolymer compound is a compound having a unit represented by the following formula (2), a unit represented by formula (3), and a unit represented by formula (4) in a molar ratio of n:m:o. In this specification, the unit represented by formula (2) will also be referred to as a long-chain alkyl group-containing unit, the unit represented by formula (3) will also be referred to as an unsaturated carbon bond-containing unit, and the unit represented by formula (4) will also be referred to as a silicone chain-containing unit. (X in formulas (2) to (4) １ ~X ３ , Y １ ~Y ３ , Z １ , Z ２ , R, k, p, q, r, and s have the same meanings as in formula (1).

[0017] The copolymer compound has a long-chain alkyl group-containing unit, which is crystalline, and therefore has a melting point above a certain level. Therefore, it is unmelted at room temperature but melts at high temperatures. As a result, it is believed that resin compositions containing the copolymer compound and sheets made of the resin composition have good handleability at room temperature and high compressibility at high temperatures. In addition, the copolymer compound has an unsaturated carbon bond-containing unit, and the unsaturated carbon bond in the unit functions as a crosslinking group and reacts with the polyorganosiloxane described below, particularly the polyorganosiloxane (A), to form a crosslinked product. This makes the copolymer compound more compatible with the polyorganosiloxane, improving the toughness of the resin composition and improving reworkability. Furthermore, the copolymer compound has a silicone chain-containing unit, which makes it more compatible with the polyorganosiloxane and its cured product, improving dispersibility. In addition, the presence of a silicone chain in the side chain is thought to reduce the amount of bleeding and further increase compressibility at high temperatures.

[0018] X in the copolymer compound １ ~X ３ are each independently a trivalent organic group. １ ~X３ may have a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom, but preferably does not have a heteroatom. １ ~X ３ are each preferably independently a hydrocarbon group. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, but is more preferably an aliphatic hydrocarbon group. １ ~X ３ are preferably each independently a trivalent hydrocarbon group having from 2 to 6 carbon atoms, more preferably a hydrocarbon group having from 2 to 3 carbon atoms. The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but is preferably a saturated hydrocarbon group. １ ~X ３ are each independently a group represented by the following formula (5) or (6): １ is a group represented by formula (5), X ２ and X ３ is particularly preferably a group represented by formula (6). (In formulas (5) and (6), *1 is a bond bonded to an atom constituting the main chain of the copolymer compound, *2 and *3 are Y １ , Y ２ or Y ３ (The bond that bonds to

[0019] Y １ ~Y ３ are each independently a divalent organic group. １ ~Y ３ are each independently preferably an organic group having 1 to 10 carbon atoms, and more preferably an organic group having 1 to 6 carbon atoms. １ ~Y ３ may have a heteroatom such as an oxygen atom, a nitrogen atom or a sulfur atom, preferably has an oxygen atom or a nitrogen atom, more preferably has an oxygen atom. １ ~Y ３ are each independently preferably a divalent organic group containing an ester group or an amide group, and more preferably an organic group containing an ester group.１ ~Y ３ It is more preferable that Y are each independently a group represented by the following formula (7) or (8). １ is a group represented by formula (7), Y ２ and Y ３ is particularly preferably a group represented by formula (8). In formula (7) and formula (8), *4 is a bond bonding to an atom constituting the main chain of the copolymer compound, and *5 is a bond bonding to an atom constituting the side chain of the copolymer compound. Ra in formula (8) is an alkylene group having 1 to 10 carbon atoms, preferably an alkylene group having 1 to 4 carbon atoms.

[0020] Z １ is a monovalent organic group. The organic group preferably has 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms. １ may have a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom, but preferably does not have a heteroatom. １ is preferably a hydrocarbon group. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, but is preferably an aliphatic hydrocarbon group. １ is preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 4 carbon atoms. The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but is preferably a saturated hydrocarbon group. １ are each independently preferably an alkyl group, and more preferably an alkyl group having 1 to 4 carbon atoms. The alkyl group may be linear or may have a branched structure. １ is more preferably a methyl group.

[0021] Z ２ is a hydrogen atom or a monovalent organic group. ２ is preferably a monovalent organic group. ２ is a monovalent organic group, Z ２ Is Z １ may be the same organic group as Z１ may be an organic group different from Z １ It is preferable that Z is the same organic group as ２ The monovalent organic group in １ Since this is as explained in the description of the above, detailed explanation will be omitted.

[0022] In formula (1), k is a methylene group (-CH ２ k is the number of (-) and is a number of 16 or more and 33 or less. By setting k in this range, the copolymer compound has a melting point of a certain level or more, and the resin composition can be made easy to handle at room temperature while improving its compressibility at high temperatures and further improving its reworkability. k is preferably 16 or more and 30 or less, and more preferably 17 or more and 25 or less. In formula (1), Y １ The moiety that forms a long-chain alkyl group bonded to "-(CH ２ There are multiple "-(CH )k-" portions depending on the number of n. ２ )k- is the average value.

[0023] Y in formula (1) ２ W bonded to is a divalent organic group and has one or more unsaturated carbon bonds. The organic group preferably has 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms. W may have a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom, but preferably has no heteroatoms. That is, W is preferably an unsaturated hydrocarbon group. The unsaturated hydrocarbon group is preferably an unsaturated aliphatic hydrocarbon group. W is preferably an unsaturated hydrocarbon group having 1 to 10 carbon atoms, more preferably an unsaturated hydrocarbon group having 1 to 4 carbon atoms. The unsaturated carbon bond may be a reactive double bond or a reactive triple bond, but is preferably a reactive double bond. In particular, W more preferably contains one or more vinylidene groups or vinylene groups, even more preferably contains one or more vinylidene groups, even more preferably contains one vinylidene group, and is particularly preferably a vinylidene group.

[0024] Y in formula (1)３ -(SiO ４／２ ) p -(SiRO ３／２ ) q -(SiR ２ O ２／２ ) r -(SiR ３ O １／２ ) s The - part is a silicone chain. Generally, as shown below, SiR ３ O １／２ The part is M unit, SiR ２ O ２／２ The part is D unit, SiRO ３／２ The part is a T unit, SiO ４／２ This part is called the Q unit. The silicone chain in formula (1) is SiR ３ O １／２ (M units), SiR ２ O ２／２ (D units), and optionally SiRO ３／２ (T units) and SiO ４／２ (Q units) or both of SiR ３ O １／２ (M units), SiR ２ O ２／２ (D units), SiRO ３／２ (T units), SiO ４／２ The arrangement of the Q units is not particularly limited. In formula (1), p, q, r, and s each represent SiO ４／２ (Q units), SiRO ３／２ (T units), SiR ２ O ２／２ (D units), SiR ３ O １／２ (M units). ３ O １／２ (M unit) is monovalent and is the terminal portion of the silicone chain. SiR ２ O ２／２ (D unit) is divalent and is the linear part of the silicone chain. SiRO ３／２ (T unit) is trivalent, and the three oxygen atoms are each bonded to one of the units to form a branched structure. ４／２(Q unit) is tetravalent, and the four oxygen atoms are each bonded to any one of the units to form a branched structure.

[0025] Y in formula (1) ３ R in the silicone chain bonded to is a monovalent organic group. The organic group preferably has 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms. R may have a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom, but preferably does not have a heteroatom. That is, R is preferably a hydrocarbon group. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, but is preferably an aliphatic hydrocarbon group. R is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 4 carbon atoms. The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but is preferably a saturated hydrocarbon group. R is preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably at least one selected from a methyl group and a butyl group. Furthermore, of the multiple Rs in one molecule, preferably 50% or more are methyl groups, more preferably 80% or more are methyl groups, and even more preferably 90% or more are methyl groups.

[0026] It is preferable that m, n, and o in formula (1) satisfy the relationship of the following formula (α): m / (n+m+o)≧0.01 Formula (α) When m / (n+m+o) is 0.01 or more as described above, the reworkability of the resin composition is likely to be improved. Note that m / (n+m+o) is an index of the content ratio of unsaturated carbon bond-containing units in the copolymer compound of formula (1), and a certain value or more is effective in improving the reworkability of the present invention. From this perspective, m / (n+m+o) is more preferably 0.015 or more, even more preferably 0.025 or more, even more preferably 0.04 or more, and preferably 0.1 or less, more preferably 0.08 or less.

[0027] In the copolymerizable compound of formula (1), r is a number of 1 or more. r is preferably 5 or more and 200 or less, more preferably 10 or more and 150 or less, and even more preferably 30 or more and 100 or less. When r is within the above range, the compressibility of the resin composition is likely to be improved. Furthermore, when r is within the above range, bleeding is also likely to be reduced.

[0028] Furthermore, it is preferable that m, n, o, and r in formula (1) satisfy the relationship of the following formula (β): o*r / (n+m+o)≧1.00 Formula (β) When o*r / (n+m+o) is 1.00 or more as described above, the compressibility of the resin composition is likely to be improved. Note that o*r / (n+m+o) is an index of the content of the linear portion of the silicone chain (D unit) in the copolymer compound of formula (1), and a certain value or more is effective for the compressibility effect of the present invention. From this perspective, o*r / (n+m+o) is more preferably 1.02 or more, even more preferably 1.05 or more, and preferably 10.0 or less, more preferably 7.0 or less.

[0029] In the copolymerizable compound of formula (1), s is a number of 1 or more. s is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less, and even more preferably 1. In the copolymerizable compound of formula (1), p is a number of 0 or more, preferably 0 or more and 5 or less, more preferably 0 or more and 1 or less, and even more preferably 0. In the copolymerizable compound of formula (1), q is a number of 0 or more, preferably 0 or more and 5 or less, more preferably 0 or more and 1 or less, and even more preferably 0. In formula (1), Y ３ There are multiple silicone chains bonded to the compound according to the number of o. The values ​​of p, q, r, and s in formula (1) are calculated as average values ​​for multiple silicone chains.

[0030] In formula (1), n, m, and o correspond to the number of long-chain alkyl group-containing units, unsaturated carbon bond-containing units, and silicone chain-containing units, respectively. These numbers are preferably set as follows from the viewpoint of improving the reworkability while improving the compressibility of the resin composition at high temperatures. n is a number of 1 or more, for example, 5 to 1000, preferably 10 to 500, more preferably 50 to 300, and even more preferably 100 to 250. m is a number of 1 or more, preferably 2 to 70, more preferably 3 to 50, and even more preferably 5 to 40. o is a number of 1 or more, preferably 3 to 70, more preferably 5 to 50, and even more preferably 8 to 40.

[0031] In the formula (1), n, m, o, k, p, q, r, and s are １ H-NMR, ２９ It can be determined by Si-NMR, size exclusion chromatography, etc., and the details are as described in the Examples.

[0032] The method for producing the copolymer compound is not particularly limited, but for example, a method of polymerizing a monomer for forming a long-chain alkyl group-containing unit represented by formula (2), a monomer for forming an unsaturated carbon bond-containing unit represented by formula (3), and a monomer for forming a silicone chain-containing unit represented by formula (4).In the following description, the monomer for forming the long-chain alkyl group-containing unit represented by formula (2) will be referred to as a crystalline monomer, the monomer for forming the long-chain alkyl group-containing unit represented by formula (3) will be referred to as a crosslinkable monomer, and the monomer for forming the silicone chain-containing unit represented by formula (4) will be referred to as a silicone monomer.Examples of the crystalline monomer include (meth)acrylic acid alkyl esters.Examples of the crosslinkable monomer include unsaturated carbon bond-containing (meth)acrylates represented by the following formula (X), which are represented by isoprenyl group-containing (meth)acrylates.

[0033] (In formula (X), R is a hydrogen atom or a methyl group, and Z ２ and W have the same meaning as in formula (1), and Ra has the same meaning as in formula (8).

[0034] Examples of the silicone monomer include one-end (meth)acrylic acid-modified silicones in which one end of the silicone chain is modified with (meth)acrylic acid. Note that (meth)acrylic is a concept that includes both acrylic and methacrylic.

[0035] [Resin Composition] The present invention also provides a resin composition containing the copolymer compound described above. The copolymer compound is preferably used in a composition containing a silicone resin other than the copolymer compound. Therefore, the resin composition of the present invention preferably contains the copolymer compound described above and a polyorganosiloxane other than the copolymer compound (hereinafter also referred to as polyorganosiloxane (X)). The polyorganosiloxane (X) preferably serves as a matrix resin in the resin composition. By including the copolymer compound described above, the resin composition of the present invention can improve handleability, high-temperature compressibility, reworkability, and the like.

[0036] The content of the copolymerizable compound in the resin composition is not particularly limited, but is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, relative to 100 parts by mass of the polyorganosiloxane (X) contained in the resin composition. When the content of the copolymerizable compound is 5 parts by mass or more, the handleability, compressibility, and reworkability of the resin composition are likely to be improved. In addition, from the viewpoint of making it easier to reduce the amount of bleed in the resin composition, the content of the copolymerizable compound in the resin composition is, for example, 110 parts by mass or less, preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less, relative to 100 parts by mass of the polyorganosiloxane (X). That is, the content of the copolymerizable compound in the resin composition is, for example, 5 parts by mass or more and 110 parts by mass or less, preferably 5 parts by mass or more and 50 parts by mass or less, more preferably 10 parts by mass or more and 40 parts by mass or less, and even more preferably 15 parts by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the polyorganosiloxane (X).

[0037] More specifically, the resin composition of the present invention preferably contains, as the polyorganosiloxane (X), at least a polyorganosiloxane having a molecular skeleton in which a hydrogen atom directly bonded to a silicon atom (hereinafter also referred to as "polyorganosiloxane (A)"). The resin composition of the present invention is preferably used as a thermally conductive resin composition, and preferably further contains a catalyst and a thermally conductive filler.

[0038] <Polyorganosiloxane (A)> Polyorganosiloxane (A) has a hydrogen atom directly bonded to a silicon atom in its molecular skeleton. Therefore, polyorganosiloxane (A) has at least one hydrosilyl group (SiH) in its molecular skeleton per molecule. By having SiH in its molecular skeleton, the reactivity with the copolymer compound is increased, and the reworkability of the cured resin composition can be improved. The number of SiH in one molecule of polyorganosiloxane (A) may be one or more. In order to form a crosslinked structure in the cured product, polyorganosiloxane (A) preferably contains a polyorganosiloxane having two or more SiH groups per molecule. A polyorganosiloxane having two or more SiH groups per molecule may be used alone or in combination with a polyorganosiloxane having one or more SiH groups.

[0039] Examples of the polyorganosiloxane (A) include methylhydrosiloxane-dimethylsiloxane copolymer, polymethylhydrosiloxane, polyethylhydrosiloxane, methylhydrosiloxane-phenylmethylsiloxane copolymer, etc. These may or may not contain SiH groups at the terminals.

[0040] In addition to the polyorganosiloxane (A), the resin composition preferably further contains a polyorganosiloxane (X) having a carbon-carbon double bond in its molecular skeleton (hereinafter also referred to as polyorganosiloxane (B)). By including the polyorganosiloxane (B), a crosslinked structure is more likely to be formed in the cured product, and reworkability is more likely to be improved. Examples of the polyorganosiloxane (B) include polyorganosiloxanes having alkenyl groups. The number of alkenyl groups in one molecule of the polyorganosiloxane is preferably 2 or more, and it is more preferable that alkenyl groups are contained at both ends. Furthermore, as the polyorganosiloxane having an alkenyl group, a polyorganosiloxane having a vinyl group is preferred. Specific examples of polyorganosiloxanes having vinyl groups include polyorganosiloxanes having vinyl groups at both ends, such as polydimethylsiloxane having vinyl groups at both ends, polyphenylmethylsiloxane having vinyl groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer having vinyl groups at both ends, dimethylsiloxane-phenylmethylsiloxane copolymer having vinyl groups at both ends, and dimethylsiloxane-diethylsiloxane copolymer having vinyl groups at both ends. When the resin composition contains polyorganosiloxane (A) and polyorganosiloxane (B), polyorganosiloxane (A) and polyorganosiloxane (B) serve as matrix resins, and the matrix resin is addition reaction curable.

[0041] The viscosity of the polyorganosiloxane (X) at 25 ° C. is preferably 5 mPa · s or more and 1000 mPa · s or less, more preferably 30 mPa · s or more and 700 mPa · s or less, and even more preferably 50 mPa · s or more and 600 mPa · s or less. The viscosity of the polyorganosiloxane is preferably measured using a viscometer (BROOKFIELD rotational viscometer DV-E) with a spindle No. 14 rotor at a rotation speed of 5 rpm and a measurement temperature of 25 ° C. As described above, when the polyorganosiloxane contains polyorganosiloxane (A) and polyorganosiloxane (B), the viscosity of the mixture at 25 ° C. is preferably within the above range, but the viscosity of the polyorganosiloxane (A) and the polyorganosiloxane (B) at 25 ° C. may each be within the above range.

[0042] (Catalyst) The catalyst contained in the resin composition may be used as a curing catalyst for the polyorganosiloxane (A) and the copolymer compound, or for the polyorganosiloxanes (A) and (B). Specifically, platinum-based catalysts, palladium-based catalysts, rhodium-based catalysts, etc. can be used, and among these, platinum-based catalysts are preferred. The amount of the curing catalyst is usually 0.1 to 200 ppm, preferably 0.5 to 100 ppm, based on the total mass of the addition reaction-curable polyorganosiloxane.

[0043] A curing retarder may be blended into the resin composition. Known curing retarders can be used, including, for example, acetylene compounds such as 1-ethynyl-1-cyclohexanol and 3,5-dimethyl-1-hexyn-3-ol, various nitrogen compounds such as tributylamine and tetramethylethylenediamine, organic phosphorus compounds such as triphenylphosphine, oxime compounds, and organic chloro compounds. By incorporating a curing retarder to suppress the catalytic activity of the curing catalyst, the shelf life and pot life of the resin composition can be extended. The content of the curing retarder in the resin composition is preferably 0.01 to 2 parts by mass, more preferably 0.1 to 1 part by mass, per 100 parts by mass of polyorganosiloxane (X).

[0044] The resin composition may further contain, as the polyorganosiloxane (X), a polyorganosiloxane other than the above-described polyorganosiloxane (A) and polyorganosiloxane (B) (hereinafter also referred to as other polyorganosiloxanes). Examples of other polyorganosiloxanes include silicone oils such as dimethyl silicone oil and polyphenylmethylsiloxane. The content of other polyorganosiloxanes in the resin composition is, for example, 10% by mass or less, preferably 5% by mass or less, and more preferably 3% by mass or less, based on the total amount of polyorganosiloxane (X).

[0045] <Thermal conductive filler> The resin composition of the present invention may contain a thermal conductive filler as described above. By containing the thermal conductive filler, the thermal conductivity of the resin composition is improved, and heat dissipation properties are enhanced. The type of thermal conductive filler is not particularly limited, but is preferably at least one selected from the group consisting of metals, inorganic hydroxides, inorganic oxides, inorganic nitrides, carbon fibers, graphite, and diamonds.

[0046] Examples of the metals include aluminum, copper, and nickel. Examples of the inorganic hydroxides include aluminum hydroxide, calcium hydroxide, and magnesium hydroxide. Examples of the inorganic oxides include iron oxide, zinc oxide, silicon oxide (silica), alumina, magnesium oxide, titanium oxide, cerium oxide, and zirconium oxide. Examples of the inorganic nitrides include silicon nitride, aluminum nitride, gallium nitride, chromium nitride, tungsten nitride, magnesium nitride, molybdenum nitride, lithium nitride, and boron nitride. Examples of the carbon fibers include pitch-based carbon fibers, PAN-based carbon fibers, fibers obtained by carbonizing resin fibers, and fibers obtained by graphitizing resin fibers. Examples of the graphite include natural graphite and artificial graphite. Examples of the diamonds include as-grown particles, crushed diamond particles obtained by crushing as-grown particles, or other diamond particles, and two or more of these may be used in combination. Generally, as-grown particles are crystalline diamond particles that maintain the shape of the diamond particles at the time of synthesis without being crushed, and have a polyhedral shape.Crushed diamond particles are obtained by crushing crystalline diamond particles, and generally have an angular shape due to crushing.These thermally conductive fillers can be used alone or in combination of two or more kinds.

[0047] Among the above-mentioned thermally conductive fillers, from the viewpoint of facilitating improvement in thermal conductivity, it is preferable to include at least one of inorganic oxides and carbon fibers, and it is more preferable to include at least one of alumina and carbon fibers, with alumina being even more preferable.

[0048] At least one type of thermally conductive filler has an anisotropic shape, and the thermally conductive filler having an anisotropic shape (hereinafter also referred to as "anisotropic filler") is preferably oriented in the thermally conductive sheet described below. The orientation of the anisotropic filler in the thermally conductive sheet facilitates improvement of thermal conductivity. It is more preferable that the anisotropic filler is oriented in the thickness direction of the thermally conductive sheet.

[0049] Examples of anisotropic fillers include fibrous materials and scaly materials. Anisotropic fillers have a high aspect ratio, specifically, an aspect ratio of greater than 2, preferably 5 or greater. Increasing the aspect ratio to greater than 2 makes it easier to orient the anisotropic filler in one direction, such as the thickness direction, and thus improves the thermal conductivity of the thermal conductive sheet in one direction, such as the thickness direction. The upper limit of the aspect ratio is not particularly limited, but is practically 100. The aspect ratio is the ratio of the length of the anisotropic filler's major axis to the length of its minor axis. In the case of fibrous materials, this means the fiber length / fiber diameter, and in the case of scaly materials, it means the length of the major axis of the scaly material / thickness.

[0050] The anisotropic filler is not particularly limited, but examples of the above-mentioned fillers that can be used include carbon fiber and boron nitride, with carbon fiber being preferred. In this specification, the term "oriented" specifically refers to the following: When the anisotropic filler is a fibrous filler, the proportion of anisotropic fillers whose major axes form an angle of less than 30° with any one direction (e.g., the thickness direction) within the thermally conductive sheet exceeds 50% of the total amount of anisotropic fillers, and this proportion is preferably greater than 80%. When the anisotropic filler is a scaly filler, the proportion of anisotropic fillers whose scale surfaces form an angle of less than 30° with any one direction within the thermally conductive sheet exceeds 50% of the total amount of anisotropic fillers, and this proportion is preferably greater than 80%. Furthermore, when the anisotropic filler is neither fibrous nor flaky, this means that the proportion of the number of anisotropic fillers whose major axes form an angle of less than 30° with any one direction within the thermal conductive sheet exceeds 50% of the total amount of anisotropic fillers, and this proportion preferably exceeds 80%.

[0051] The anisotropic filler can be oriented by known methods, such as magnetic field orientation, in which a magnetic field is applied to the uncured composition to orient it in one direction, or flow orientation, in which a shear force is applied to the uncured composition to orient it in one direction. In the case of flow orientation, for example, the uncured composition is flattened and stretched while applying shear force using a coating applicator such as a bar coater or doctor blade, or by extrusion molding or discharge from a nozzle, to form a sheet (primary sheet) in which the anisotropic filler is oriented along the surface direction. The primary sheets are then stacked to obtain a block-shaped oriented molded product, which is then cut in the orientation direction of the anisotropic filler to orient it in the thickness direction.

[0052] The thermally conductive filler may also contain a non-anisotropic filler in addition to the anisotropic filler. The non-anisotropic filler is a filler that has substantially no anisotropy in shape and does not orient in a predetermined direction even under conditions in which the anisotropic filler would orient in a predetermined direction, such as under magnetic field lines or shear force. The non-anisotropic filler has an aspect ratio of 2 or less, preferably 1.5 or less. When used in combination with an anisotropic filler, a non-anisotropic filler with such a low aspect ratio is more likely to be located in the gaps between the anisotropic filler, thereby improving thermal conductivity. Furthermore, the thermally conductive filler may be used alone without the anisotropic filler.

[0053] The average particle size of the thermally conductive filler is not particularly limited, but is preferably 0.1 μm to 250 μm, and more preferably 0.2 μm to 100 μm. The average particle size can be measured, for example, using a laser diffraction particle size distribution analyzer manufactured by Horiba, Ltd. The particle size at 50% of the cumulative volume (d50) can be taken as the average particle size.

[0054] The thermally conductive filler preferably contains two or more types of particles with different average particle sizes. When two or more types of particles with different average particle sizes are used, the particles with the smaller average particle size are inserted between the particles with the larger average particle size, making it easier to properly disperse the thermally conductive filler in the polyorganosiloxane while increasing the filling rate of the thermally conductive filler. Note that a resin composition can be determined to contain two or more types of particles with different average particle sizes if two or more peaks appear in the particle size distribution of the thermally conductive filler.

[0055] The amount of the thermally conductive filler is preferably 60% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more, based on the total amount of the resin composition. When the amount of the thermally conductive filler is equal to or greater than these lower limits, the thermal conductivity of the resin composition is easily improved. The upper limit of the amount of the thermally conductive filler is not particularly limited, but is, for example, 95% by mass or less, based on the total amount of the resin composition.

[0056] (Other Additives) The resin composition of the present invention may contain, as necessary, additives commonly used in resin compositions, such as a dispersant such as a silane coupling agent, an antioxidant, a heat stabilizer, a colorant, a flame retardant, and an antistatic agent.

[0057] <Cured Product> The present invention can also provide a cured product of the resin composition obtained by curing the above-described resin composition. The cured product can be formed by forming the resin composition into a predetermined shape, such as a sheet, and then appropriately heating it. The cured product can be used as a heat dissipation member. The heat dissipation member is used, for example, inside an electronic device. A heat dissipation member made from a cured product of the resin composition of the present invention has good thermal conductivity, so when used inside an electronic device, high heat dissipation can be ensured even when a large amount of heat is generated. Furthermore, the heat dissipation member has excellent handleability at room temperature and excellent compressibility at high temperatures. Furthermore, the amount of bleeding is small, resulting in excellent product reliability. The heat dissipation member is, for example, placed on an electronic component to dissipate heat generated by the electronic component. The heat dissipation member of the present invention may also be used by being placed so as to fill the gap between two opposing components. The two opposing components may, for example, be one electronic component and the other a heat sink, electronic device housing, or substrate for dissipating heat from the electronic component. The heat dissipation member may be used as a so-called TIM (Thermal Interface Material). Furthermore, since the cured product of the resin composition has excellent reworkability, even when the cured product is peeled off from the adherend for the purpose of replacing the cured product, for example, the cured product can be prevented from rupturing, and part of the cured product can be prevented from remaining on the adherend.

[0058] When the cured product of the resin composition is in the form of a sheet, the cured product can be used as a thermally conductive sheet, which is a sheet-shaped heat dissipation member. The thickness of the thermally conductive sheet is preferably 0.05 mm or more and 5 mm or less, more preferably 0.1 mm or more and 4.5 mm or less, and even more preferably 0.2 mm or more and 4 mm or less. When the thickness of the cured product is a certain level or more, it is easy to improve the thermal conductivity. Furthermore, when the thickness of the cured product is a certain level or less, it can be suitably used in narrow places, such as inside electronic devices.

[0059] [Thermal Conductive Material] In another aspect, the present invention also provides a thermally conductive material comprising a polyorganosiloxane (X), a thermally softening compound, and a thermally conductive filler. The thermally conductive material has a T2 relaxation curve of a pulse NMR measured by a solid echo method at 10°C, the T2 relaxation curve being a function represented by the following formula (12) when analyzed by least squares fitting. １ The proportion of is 10% or more. (In formula (12), a １ , a ２ , and a ３ is a １ +a ２ +a ３ = 100%, and t １ , t ２ , and t ３ is the T2 relaxation time of each relaxation component, and t １ <t ２ <t ３ and x is the observation time in the pulsed NMR relaxation measurement.

[0060] Pulsed NMR instruments can primarily acquire the T1 and T2 relaxation curves of hydrogen nuclei. By analyzing these curves, the T1 and T2 relaxation times can be analyzed, both of which vary according to the correlation time τc of molecular motion according to the Bloenbergen-Purcell-Pound equation (BPP equation). Therefore, molecular mobility can be analyzed from the T1 and T2 relaxation times. However, since the T1 relaxation time of hydrogen nuclei is affected by spin diffusion and is also influenced by factors other than mobility, it is generally difficult to use the T1 relaxation time of hydrogen nuclei for mobility analysis. On the other hand, the T2 relaxation time is not affected by spin diffusion and clearly reflects molecular mobility, so it is used exclusively for material mobility analysis and mobility component division analysis within materials.

[0061] The T2 relaxation time has a monotonous correlation with the correlation time τc of molecular motion, and the longer the τc of a material, the shorter the T2 relaxation time, and the shorter the τc of a material, the longer the T2 relaxation time. Since τc is the reciprocal of the frequency of molecular motion, it is known that the lower the mobility of a material, the shorter the T2 relaxation time, and the higher the mobility of a material, the longer the T2 relaxation time.

[0062] As mentioned above, it is possible to discuss mobility from the T2 relaxation time, but there are several methods for measuring T2 relaxation time. Among them, the solid echo method is a technique suitable for measuring materials with relatively low mobility, i.e., materials with short T2 relaxation times. In pulsed NMR, ringing occurs due to electromagnetic force immediately after pulse irradiation, making it difficult to directly observe the initial stage of the relaxation curve. Therefore, since direct observation cannot observe short relaxation components that decay during the dead time, echo observation such as the solid echo method is exclusively used.

[0063] The pulse configuration of the solid echo method is expressed as 90°x-τ-90°y. This method observes the echo induced by the second pulse, rather than the relaxation that occurs immediately after excitation, making it possible to observe very fast relaxation that decays during the apparent dead time. On the other hand, the solid echo method observes free relaxation, so it is significantly affected by magnetic field inhomogeneity. In materials with large diffusion coefficients, intensity decay due to diffusion predominates, resulting in a large discrepancy between the apparent T2 relaxation time and the true T2 relaxation time. Therefore, the solid echo method is primarily used to observe components with short T2 relaxation times, i.e., components with low mobility. In the above pulse configuration, 90°x means that the macroscopic spin in the rotating coordinate system is tilted 90° along the x-axis, and 90°y means that the macroscopic spin in the rotating coordinate system is tilted 90° along the y-axis. τ represents the delay time between two 90° pulses.

[0064] a in formula (12) １ is a quantitative expression of the amount of the component in which molecular motion is most suppressed in the thermally conductive material.１ A ratio of less than 10% means that there are few components whose molecular motion is suppressed, and indicates a state in which the thermosoftening compound is not sufficiently dispersed in the polyorganosiloxane (X). Therefore, there is a risk that high-temperature compressibility and room temperature handleability may be insufficient. １ The ratio of a is preferably 10.1% or more, and more preferably 12% or more. １ The ratio is not particularly limited, but is, for example, 30% or less, and preferably 25% or less.

[0065] When measuring pulse NMR at 10 ° C., the crystalline moieties in the thermosoftening compound crystallize, suppressing molecular motion. The thermosoftening compound has, for example, a polyorganosiloxane moiety, which provides good compatibility with polyorganosiloxane (X). Therefore, when a thermosoftening compound is blended into a thermally conductive material and the molecular motion of the crystalline moieties in the thermosoftening compound is suppressed in the thermally conductive material, the molecular motion of the polyorganosiloxane (X) present around the crystalline moiety is also suppressed in conjunction with the crystalline moiety. On the other hand, when a thermosoftening compound having a crystalline moiety is blended into a resin that is poorly compatible with the compound, the molecular motion of the crystalline moiety is suppressed, but the molecular motion of the resin present around the crystalline moiety is not suppressed. The present invention provides a blending design that suppresses molecular motion not only of the thermosoftening compound having a crystalline moiety but also of the polyorganosiloxane (X) at low temperatures, thereby achieving a higher molecular motion than conventional methods. １ It is possible to provide a highly thermally conductive material.

[0066] The thermally conductive material of the present invention may or may not be curable. That is, the thermally conductive material of the present invention may be a composition containing polyorganosiloxane (X), a thermosoftening compound, and a thermally conductive filler, or a cured product thereof. When the thermally conductive material is curable, the pulse NMR measurement may be performed either before or after curing, but it is preferable to perform the measurement in accordance with the usage mode. When the thermally conductive material is curable, it is preferable that the thermally conductive material is cured.

[0067] A thermosoftening compound is a compound that has a crystalline portion and softens when it reaches a certain temperature. Specifically, a thermosoftening compound exhibits crystallinity in an environment of 10°C, but loses its crystallinity and softens when it reaches a certain temperature. The temperature at which it loses its crystallinity and softens is expressed as its melting point. The melting point of a thermosoftening compound is, for example, 30°C or higher and 90°C or lower, preferably 35°C or higher and 80°C or lower, more preferably 40°C or higher and 60°C or lower, and even more preferably 42°C or higher and 58°C or lower.

[0068] The crystalline moiety in the thermosoftening compound is not particularly limited as long as it is a hydrocarbon moiety, preferably a straight-chain hydrocarbon moiety, more preferably a straight-chain aliphatic saturated hydrocarbon moiety. The number of carbon atoms in the hydrocarbon moiety is not particularly limited as long as it can impart crystallinity to the thermosoftening compound, but if it is a straight-chain aliphatic saturated hydrocarbon moiety, it is, for example, 16 to 33, preferably 16 to 30, more preferably 17 to 25.

[0069] The thermosoftening compound may further have a polyorganosiloxane moiety. By having a polyorganosiloxane moiety, the thermosoftening compound becomes more compatible with the polyorganosiloxane (X) that constitutes the matrix of the thermally conductive material, making it easier to suppress the molecular mobility of the entire thermally conductive material. Furthermore, the thermosoftening compound preferably further has a moiety (reactive moiety) that is reactive with the polyorganosiloxane (X) that constitutes the matrix. Having a reactive moiety allows the thermosoftening compound to bond to the matrix, making it easier to further suppress the molecular mobility of the entire thermally conductive material. The reactive moiety is preferably a crosslinking group that bonds to the polyorganosiloxane (X) and crosslinks it. Examples of reactive moieties include unsaturated hydrocarbon groups such as reactive double bonds and reactive triple bonds, with reactive double bonds being preferred. Details of the unsaturated hydrocarbon group are as described above for the copolymer compound, and it is more preferable that it contains a vinylidene group or a vinylene group.

[0070] Examples of the thermosoftening compound include the above-mentioned copolymer compounds, paraffin wax, ester wax, etc., and among these, the copolymer compounds are preferred. By using a copolymer compound as the thermosoftening compound, compatibility with the polyorganosiloxane (X) improves, and a １ The ratio is more likely to be adjusted to a certain level.

[0071] The polyorganosiloxane (X) used in the thermally conductive material is a polyorganosiloxane other than a thermally softening compound, and is not particularly limited as long as it is a polyorganosiloxane that constitutes the matrix resin of the thermally conductive material. Specifically, it may be a curable polyorganosiloxane such as an addition reaction curable polyorganosiloxane or a condensation type polyorganosiloxane, or a non-curable polyorganosiloxane such as silicone oil. Among these, addition reaction curable polyorganosiloxanes are preferred. The addition reaction curable polyorganosiloxane may be composed of polyorganosiloxane (A) and polyorganosiloxane (B), the details of which are as described above.

[0072] The content of the thermally softening compound in the thermally conductive material is as described above in the resin composition, and is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, relative to 100 parts by mass of polyorganosiloxane (X). Furthermore, for example, it is preferably 110 parts by mass or less, 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less, relative to 100 parts by mass of polyorganosiloxane (X). The thermally conductive filler in the thermally conductive material is as described above in the resin composition, and a detailed description thereof will be omitted. The content of the thermally conductive filler is also as described above, and is preferably 60% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more, relative to the total amount of the thermally conductive material, and is, for example, 95% by mass or less.

[0073] The thermally conductive material may contain components other than the polyorganosiloxane (X), the heat-softening compound, and the thermally conductive filler described above. For example, if the polyorganosiloxane (X) is addition reaction curable, it may contain a catalyst. The thermally conductive material may also contain a cure retarder, or may contain other additives other than the catalyst and the cure retarder. Details of these catalysts, cure retarders, and other additives are as described above.

[0074] In another aspect, the thermally conductive material may be a cured product cured as described above. Details of the cured product are as described above for the cured product of the resin composition, and may be used, for example, in sheet form. When the thermally conductive material is used in sheet form, the thickness of the thermally conductive material is as described above for the cured product of the resin composition. The thermally conductive material may also be used in forms other than sheet form, and may be used in an irregular shape such as grease. The thermally conductive material can also be used as a heat dissipation member, and details of its use are as described above, and it may be used, for example, inside electronic devices. In another aspect of the present invention, the thermally conductive material is particularly preferably a cured product of a resin composition containing the copolymer compound described above.

[0075] The present invention will be clarified below by showing specific examples and comparative examples of the present invention, but the present invention is not limited to the following examples.

[0076] [Copolymer Compound] The following materials were used as raw materials for synthesizing the copolymer compound.

[0077] (Silicone Monomer) - One-Terminated Methacrylic-Modified Silicone Viscosity at 25°C: 60 cSt A compound having a structure represented by the following formula (9).

[0078] (Crystalline monomer) Stearyl acrylate (Crosslinkable monomer) Isoprenyl methacrylate (IPEMA)

[0079] (Initiator) 5 wt% azo initiator toluene solution (Solvent) Toluene

[0080] <Synthesis of Copolymer Compound> Silicone monomer, crystalline monomer, and crosslinkable monomer were mixed in toluene and ２ Bubbling was continued for 20 minutes or more. Heating was initiated, and after the temperature had risen to 62°C, a 5 wt% toluene solution of an azo-based initiator was added. After heating and stirring at 62°C for 17 hours, the mixture was allowed to cool, the solvent was distilled off, and the mixture was heated under vacuum at 150°C for 2 hours to synthesize copolymer compounds PCM (E1) to PCM (E6). The amount of each raw material added is shown in Table 1.

[0081] PCM (E1) to PCM (E6) are compounds having the structure of the above-mentioned formula (1), and more specifically, have a structure represented by the following formula (10). Tables 2 and 3 show the details of the structures of PCM (E1) to PCM (E6).

[0082] <Synthesis of Comparative Copolymer Compound: PCM (C1)> PCM (C1) was obtained in the same manner as in the synthesis of the above copolymer compounds, except that no crosslinking monomer was used. As with PCM (E1) to PCM (E6), the number of parts of each raw material added is shown in Table 1.

[0083] PCM (C1) has the structure shown in formula (11) below.

[0084]

[0085]

[0086] <PCM other than copolymer compound> In addition to PCM (C1), the following PCM (C2) was also used as a PCM other than a copolymer compound. The structures of PCM (C1) and (C2) are detailed in Table 3. PCM (C2) HS-Crysta 4100P, manufactured by Toyokuni Oil Mills, poly-α-olefin, melting point 35°C

[0087]

[0088] <Weight-average molecular weight> The weight-average molecular weight (Mw) of each synthesized PCM was measured by size exclusion chromatography using THF as a solvent. The weight-average molecular weight (Mw) was expressed as a standard polystyrene equivalent value.

[0089] <Melting Point> The melting point of each synthesized product (each PCM) was determined by measurement using a differential scanning calorimeter (DSC). The temperature was changed at a rate of 10°C / min from -20°C to 100°C to -20°C to 100°C. The peak temperature of the maximum peak in the chart obtained during the temperature drop from 100°C to -20°C (Temperature 1) and the peak temperature of the maximum peak in the chart obtained during the second temperature increase from -20°C to 100°C (Temperature 2) were obtained, and the average value of Temperature 1 and Temperature 2 was taken as the melting point.

[0090] <Calculation of each structural parameter of formula (1)> (Calculation of p, q, r, s) of each synthesized PCM ２９ The Si NMR spectrum was measured in a 0.1% tetramethylsilane-d-chloroform solution. The tetramethylsilane peak was set at 0 ppm, and the peaks around 6.5 to 9.0, 20 to 24, -55 to -65, and -105 to -115 ppm were assigned to (SiO1 / 2), (SiO2 / 2), (SiO3 / 2), and (SiO4 / 2), respectively, and p, q, r, and s were determined using the following formula. However, if R is other than a methyl group and the peak positions differ, the following formula should be applied based on the appropriate peak assignment.

[0091] When <SiO4 / 2>≠0, p = 1 q = <SiO3 / 2> / <SiO4 / 2> r = s*<SiO2 / 2> / <SiO1 / 2> s = p*3*q*2

[0092] When <SiO4 / 2> = 0 and <SiO3 / 2> ≠ 0, p = 0 q = 1 r = s * <SiO2 / 2> / <SiO1 / 2> s = 2 * q

[0093] When <SiO4 / 2> = 0 and <SiO3 / 2> = 0, p = 0 q = 0 r = s * <SiO2 / 2> / <SiO1 / 2> s = 1 where <SiOx / 2> represents the integral value of the peak assigned to SiOx / 2.

[0094] (Calculation of k) of each synthesized PCM １The H NMR spectrum was measured in a deuterated chloroform solution and determined based on appropriate peak assignments. The formula for PCM (E1) is as follows: k = (<4.0> / <0.9> + <1.6> / <0.9> + <1.3> / <0.9>) * 3 / 2, where <x.x> represents the integral of the peak having a peak top near x.x ppm.

[0095] (Calculation of o*r / (n+m+o)) １ The H NMR spectrum was measured in a deuterated chloroform solution and determined based on appropriate peak assignments. The formula for PCM (E1) is as follows: o*r / (n+m+o)=(<0.1> / 6) / (<4.0> / 2) m / (n+m+o)=(<0.1> / 6) / (<4.0> / 2), where <x.x> represents the integral of the peak having a peak top near x.x ppm.

[0096] (Calculation of m, n, o, m+n+o) As described above, the weight average molecular weight Mw of each PCM was calculated by performing size exclusion chromatography measurement using THF solvent. Using Mw, m, n, and o were calculated from the following formula. After defining P = m + n + o, [m] = m / P, and [o] = o / P, m, n, and o were calculated using the following formulas (A) to (C), respectively. m = [m] * P Formula (A) n = (1 - [m] - [o]) * P Formula (B) o = [o] * P Formula (C)

[0097] Here, [m] and [o] are the １ From the measured values ​​of the H NMR spectrum, it can be calculated as follows: [m] = (<4.81> + <4.76>) / 2 [o] = <0.53> / 2. Using these measured values, P was calculated according to the following formula (D): P = Mw / ([m] * Mlink + [o] * Msil + (1 - [m] - [o]) * Mcryst) ... formula (D), where Mlink: formula weight of the repeating unit derived from the crosslinkable monomer, Mcryst: formula weight of the repeating unit derived from the crystalline monomer, and Msil: formula weight of the repeating unit derived from the silicone monomer. In this example, these numerical values ​​are shown in the tables, but can be determined by combining appropriate one-dimensional, two-dimensional, and multinuclear NMR spectroscopy methods.

[0098] [Examples 1-12, Comparative Examples 1-7] Predetermined amounts of thermally conductive filler, dispersant, silicone base, and PCM were mixed in a sample vial and gently mixed by hand. The mixture was then kneaded twice with a THINKY MIXER (manufactured by THINKY MIXER) at 1,400 rpm / 30 seconds. The mixture was then heated at 80°C for 30 minutes and kneaded again with the THINKY MIXER. The mixture was cooled to room temperature, and a silicone curing agent was added. The mixture was further kneaded with the THINKY MIXER and allowed to stand under vacuum for 5 minutes to degas, yielding a resin composition. The resulting resin composition was sandwiched between release films and formed into a sheet using a stretching roll. The sheet was then heated at 150°C for 1 hour to obtain a cured resin composition. The size and shape of the cured product were adjusted appropriately to suit each evaluation method. Tables 4 and 5 show the formulations of the resin compositions prepared in each Example and Comparative Example. The dispersant used was a silane coupling agent, decyltrimethoxysilane, a vinyl-based silicone polyorganosiloxane, and an organohydrogenpolysiloxane as a silicone curing agent. The silicone curing agent contained a small amount of curing catalyst. The thermally conductive fillers used were alumina with an average particle size of 0.5 μm, 3 μm, and 10 μm.

[0099] (Change in Elastic Modulus) A cured resin composition (thermally conductive material) molded into a 2 mm thick sheet was cut to create two rectangular parallelepiped test pieces measuring 6 mm in length, 6 mm in width, and 2 mm in thickness. Then, using a viscoelasticity measuring device (DVA200, manufactured by IT Measurement & Control Co., Ltd.) and a shear measurement jig, the elastic modulus was measured in the range of -10°C to 70°C. The change in elastic modulus was then calculated using the following formula: where log is a common logarithm. Note that in Comparative Examples 5 and 7, thermally conductive materials could not be produced, so elastic modulus measurement and evaluation were not performed. Elastic modulus change = log (measured at 10°C) - log (measured at 70°C). The elastic modulus measurement conditions were as follows: Temperature range: -10 to 70°C Heating rate: 10°C / min Frequency: 10 Hz Strain: 0.01% Furthermore, in Examples 1 to 6 and Comparative Examples 1 to 3, the elastic modulus was evaluated according to the following evaluation criteria. A: 1.4 or more B: 0.6 or more and less than 1.4 C: 0.4 or more and less than 0.6 D: Less than 0.4

[0100] In Examples 7 to 12 and Comparative Examples 4 and 6, the modulus of elasticity was evaluated according to the following evaluation criteria: A: 1.4 or more B: 1.2 or more and less than 1.4 C: 1.0 or more and less than 1.2 D: less than 1.0

[0101] (Elongation) A cured resin composition molded into a 2 mm thick sheet was processed into a test piece using a test piece punching blade (tensile No. 7 dumbbell type, Kobunshi Keiki Co., Ltd.). Thereafter, a tensile test was performed at 25°C using a Tensilon universal material testing machine (RTI1310, AND Co., Ltd.), and the elongation was calculated using the following formula: Elongation (%) = ((gauge line distance at break) - (gauge line distance before tensile test)) / (gauge line distance before tensile test) Then, the elongation was evaluated according to the following evaluation criteria. Note that measurement and evaluation of elongation were performed in Examples 1 to 6 and Comparative Examples 1 and 2, but not in Examples 7 to 12 and Comparative Examples 4 to 7. A: 230% or more B: 165% or more but less than 230% C: 150% or more but less than 165% D: Less than 150%

[0102] (Bleeding Amount) A cured resin composition molded into a 3.5 mm thick sheet was cut into a 20 mm x 1 mm square to prepare a test piece T, and its weight was measured (Weight 1). Each test piece T was sandwiched between metal plates and compressed to a thickness of 2 mm, and heated at 150°C for 64 hours. After heating, the test piece was removed and its weight was measured (Weight 2), and the bleed amount was calculated using the following formula: Bleeding Amount = (Weight 1 - Weight 2) / (Weight 1) The bleed amount was then evaluated according to the following evaluation criteria. Note that measurement and evaluation of the bleed amount were performed in Examples 1 to 6 and Comparative Examples 1 to 3, but not in Examples 7 to 12 and Comparative Examples 4 to 7. A: Bleeding amount is 0.3 or less B: Bleeding amount is more than 0.3 and less than 0.4 C: Bleeding amount is more than 0.4 and less than 0.5 D: Bleeding amount is more than 0.5

[0103] (Thermal Resistance) Test pieces made of cured resin compositions molded into 1.1 mm thick sheets were measured for thermal resistance using a thermal resistance measuring device as shown in FIG. 1 according to the following method. For each sample, a test piece S measuring 30 mm x 30 mm was prepared for this test. Each test piece S was then attached to a copper block 22 with a measurement surface of 25.4 mm x 25.4 mm and sides covered with thermal insulation material 21, and sandwiched between upper copper blocks 23. A load of 40 psi (0.276 MPa) was applied by a load cell 26. The lower copper block 22 was in contact with a heater 24. The upper copper block 23 was also covered with thermal insulation material 21 and connected to a heat sink 25 equipped with a fan. Next, the heater 24 was operated at a heat output of 25 W. After 10 minutes when the temperature reached a substantially steady state, the temperature (θ ｊ０ ), the temperature of the lower copper block 22 (θ ｊ１ The thermal resistance of each sample was calculated using the following formula (a). The temperature was adjusted so that the sheet temperature was 80°C. Thermal resistance = (θ ｊ１ -θ ｊ０ ) / Q Formula (a) In formula (a), θ ｊ１ is the temperature of the lower copper block 22, θ ｊ０ is the temperature of the upper copper block 23, and Q is the amount of heat generated. Then, the thermal resistance was evaluated according to the following evaluation criteria. Note that the measurement and evaluation of the thermal resistance were carried out in Examples 1 to 6 and Comparative Examples 1 to 3, but not in Examples 7 to 12 and Comparative Examples 4 to 7. A: The thermal resistance value was 1.6 m ２ ・Less than K / W B: Thermal resistance value is 1.6m ２ ・K / W or more

[0104] (Pulse NMR Measurement) 5.0 g of the cured resin composition (thermally conductive material) prepared in Examples 7 to 12 and Comparative Examples 4 and 6 was used as the measurement sample. The sample was filled into a sample tube for pulse NMR measurement, and the temperature of the sample tube was then adjusted to 10°C. The sample tube was then inserted into the main body of the measurement device, and a 10-minute holding time was allowed for temperature stabilization, and the T2 relaxation curve was measured under the following measurement conditions. Note that in Comparative Examples 5 and 7, pulse NMR measurement was not performed because a thermally conductive material could not be prepared. <Measurement time> Machine: minispec mq20 Temperature: 10dC Environment: Air Pulse sequence: Solid echo Scan: 128 Recycle delay: 1s Pulse Separation: 0.64μs Numbers of points: 9369

[0105] <Parameters> The obtained relaxation curve was fitted with the following fitting function, １ were obtained as parameters. The Weibull coefficients were fixed at W1 = 2, W2 = 2, and W3 = 1. (a1, a2, and a3 in the above fitting function are a in equation (12) １ ~a ３ and x is x in equation (12), and t is t in equation (12). １ ~t ３ are synonymous with

[0106]

[0107] The resin compositions prepared in Examples 1 to 6 contained copolymer compounds satisfying the requirements of the present invention, and the large change in elastic modulus indicated excellent handleability and high-temperature compressibility. Furthermore, the large elongation indicated excellent reworkability. Furthermore, the low bleed amount indicated high reliability, and the low thermal resistance indicated excellent thermal conductivity. In contrast, the resin composition prepared in Comparative Example 1 contained a compound not containing a carbon-carbon double bond or triple bond in the molecule instead of the copolymer compound of the present invention, resulting in low elongation and failure to exhibit excellent reworkability. Furthermore, the resin composition prepared in Comparative Example 2 contained a commercially available compound not containing a carbon-carbon double bond or triple bond in the molecule instead of the copolymer compound of the present invention, resulting in low elongation and failure to exhibit excellent reworkability, similar to Comparative Example 1. Furthermore, the resin composition prepared in Comparative Example 3 did not contain any copolymer compounds, resulting in low change in elastic modulus, indicating poor handleability and high-temperature compressibility.

[0108]

[0109] Pulse NMR measurements were carried out on the thermally conductive materials prepared in Examples 7 to 12. １ In contrast, when pulse NMR measurements were performed on the thermally conductive materials prepared in Comparative Examples 4 and 6, it was found that the ratio of a １ In Comparative Examples 5 and 7, the proportion of PCM, which has poor compatibility with polyorganosiloxane (X), was reduced, and the change in elastic modulus was small, which resulted in poor handling and high-temperature compressibility.

[0110] 21 Heat insulating material 22 Lower copper block 23 Upper copper block 24 Heater 25 Heat sink 26 Load cell S Test piece θ ｊ０Temperature of the upper copper block θ ｊ１ Temperature of the lower copper block

Claims

1. A copolymer compound having a structure represented by the following formula (1): (In formula (1), X １ ~X ３ are each independently a trivalent organic group, and Y １ ~Y ３ are each independently a divalent organic group, Z １ is a monovalent organic group, and Z ２ is a hydrogen atom or a monovalent organic group, each R is independently a monovalent organic group, W is a divalent organic group containing one or more carbon-carbon double or triple bonds, k is a number between 16 and 33, n, m, o, r, and s are each a number of 1 or greater, and p and q are each a number of 0 or greater.

2. The copolymer compound of claim 1, wherein W comprises one or more vinylidene or vinylene groups.

3. The above X １ ~X ３ The copolymer compound according to claim 1 or 2, wherein is a hydrocarbon group having from 2 to 3 carbon atoms.

4. The above Y １ ~Y ３ The copolymer compound according to claim 1 or 2, wherein contains an ester group or an amide group.

5. The copolymer compound according to claim 1 or 2, wherein m, n, and o satisfy the relationship of the following formula (α): m / (n+m+o)≧0.025 Formula (α) 6. The copolymer compound according to claim 1 or 2, wherein m, n, o, and r satisfy the relationship of the following formula (β): o*r / (n+m+o)≧1.00 Formula (β) 7. A resin composition comprising the copolymer compound according to claim 1 or 2, a polyorganosiloxane having hydrogen atoms directly bonded to silicon atoms in the molecular skeleton, a catalyst, and a thermally conductive filler.

8. The resin composition according to claim 7, further comprising a polyorganosiloxane having a carbon-carbon double bond in the molecular skeleton.

9. The resin composition according to claim 7, wherein the thermally conductive filler is at least one selected from the group consisting of metals, inorganic hydroxides, inorganic oxides, inorganic nitrides, carbon fibers, graphite, and diamonds.

10. The resin composition according to claim 7, wherein the content of the copolymer compound is 10 parts by mass or more per 100 parts by mass of the polyorganosiloxane (X) contained in the resin composition.

11. A thermally conductive sheet made from a cured product of the resin composition according to claim 7, wherein the thickness of the thermally conductive sheet is 0.05 mm or more and 5 mm or less.

12. The thermally conductive sheet according to claim 11, wherein at least one of the thermally conductive fillers has an anisotropic shape, and further wherein the thermally conductive fillers having an anisotropic shape are oriented within the thermally conductive sheet.

13. A thermally conductive material comprising a polyorganosiloxane, a thermally softening compound, and a thermally conductive filler, wherein the T2 relaxation curve of the pulse NMR measured by the solid echo method at 10°C for the thermally conductive material is analyzed by least squares fitting using a function expressed by the following equation (12), and the obtained a １ A thermally conductive material having a ratio of 10% or more. (In formula (12), a １ , a ２ , and a ３ is a １ +a ２ +a ３ = 100%, and t １ , t ２ , and t ３ are the T2 relaxation times of the respective relaxation components, t1<t2<t3, and x is the observation time in the pulsed NMR relaxation measurement.)

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