Polyorganosiloxane and resin composition

Abstract

To provide a polyorganosiloxane exhibiting adsorbability with respect to many types of fillers.SOLUTION: There is provided a polyorganosiloxane having a structure represented by the following formula (1). (Wherein, R1 each independently represents a group represented by A-B or a monovalent hydrocarbon group having 1 to 4 carbon atoms, at least one R1 of the R1 is a group represented by the A-B, the A is a divalent organic group bonded to a silicon atom, the B is three or more conjugated ring structures forming a common conjugated system and contains at least one hetero atom and n is an integer of 1 or more.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyorganosiloxane and a resin composition containing the polyorganosiloxane. [Background technology]

[0002] In recent years, with the development of communication technologies such as 5G, heat dissipation has become increasingly important for electronic devices, leading to an increased demand for heat-dissipating materials. Heat-dissipating materials are generally formed from resin compositions containing resin and filler. High filler loading or the use of fillers with higher thermal conductivity is effective in achieving high heat dissipation. However, in resin compositions containing resin and filler, poor compatibility between the resin and filler can lead to reduced flexibility and other impairments in the material's functionality. To improve this poor compatibility, additives that have affinity with both the resin and filler or that improve dispersibility in the resin are known to be added.

[0003] For example, Patent Document 1 discloses a polyorganosiloxane having a specific structure in which X is a fused ring group, and describes that a pyrene group is preferable as the fused ring group from the viewpoint of dispersibility of nanocarbons. Furthermore, Patent Document 2 discloses a polyorganosiloxane having another specific structure and having a trimethoxysilyl group at one end, and the side chain group R 1 is a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group, and examples of the monovalent aromatic hydrocarbon group include a phenyl group and a tolyl group. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-197300 A [Patent Document 2] Japanese Patent Publication No. 2023-105550 Summary of the Invention [Problem to be solved by the invention]

[0005] Recently, in order to balance cost and thermal conductivity and to more precisely design the composition, it has become common to use a filler having π electrons, such as graphite or hexagonal boron nitride (hereinafter also referred to as a "π-based filler"), in combination with an oxide filler in composite materials for heat dissipation. For example, fused-ring aromatic hydrocarbons, such as pyrene groups in polyorganosiloxanes described in Patent Document 1, are adsorbed to the π-based filler through π-π interactions. On the other hand, polar functional groups, such as alkoxysilyl groups in organopolysiloxanes described in Patent Document 2, are adsorbed to the oxide filler through hydrogen bonding interactions.

[0006] On the other hand, fused-ring aromatic hydrocarbons do not have sufficient adsorption to oxide fillers, and the polar functional groups of polar group-based additives do not have sufficient adsorption to π-based fillers. Therefore, it is considered to use, for example, the two types of polyorganosiloxanes mentioned above in combination as additives in composite materials for heat dissipation.

[0007] However, when two or more types of additives are blended, the optimal addition ratio of each additive varies depending on the blending ratio of each filler and the filler lot, which can lead to a problem of impairing the quality stability of the composite material. To address this problem, additives that have an adsorption effect on a variety of fillers are needed.

[0008] Therefore, an object of the present invention is to provide a polyorganosiloxane that exhibits excellent adsorption properties for various types of fillers and can improve the dispersibility of the fillers. [Means for solving the problem]

[0009] After extensive research, the inventors of the present invention have concluded that the introduction of a filler linker with universal adsorption properties onto the surfaces of both π-based fillers and oxide fillers would be effective. Conventional additives adsorb to fillers via either the π-π interaction of fused-ring aromatic hydrocarbons or the hydrogen bonding effect of heteroatoms, resulting in limited adsorption. Therefore, the inventors discovered that by introducing a conjugated fused-ring structure containing at least one heteroatom within the conjugated ring as an adsorption site, the π-π interaction and hydrogen bonding effect act in a complementary manner, making it possible to achieve universal effects on a variety of fillers. As a result of further investigation, the inventors have found that the above problems can be solved by introducing into polyorganosiloxane a specific conjugated ring structure containing a heteroatom in a group that is a certain distance away from the silicon atom. That is, the present invention provides the following [1] to

[11] .

[0010] [1] A polyorganosiloxane having a structure represented by the following formula (1): [ka] (In formula (1), each R1 is independently a group represented by AB or a monovalent hydrocarbon group having 1 to 4 carbon atoms, At least one of the R1 is a group represented by AB, A is a divalent organic group bonded to a silicon atom, B is a conjugated ring structure of three or more conjugated rings that form a common conjugated system and contains at least one heteroatom; n is an integer greater than or equal to 1.) [2] The polyorganosiloxane according to [1], wherein B contains a condensed ring structure. [3] The polyorganosiloxane according to [1] or [2], wherein B comprises a structure in which three or more aromatic rings are directly bonded. [4] The polyorganosiloxane according to any one of [1] to [3], wherein the heteroatom is at least one selected from a nitrogen atom, an oxygen atom, and a sulfur atom. [5] The polyorganosiloxane according to any one of [1] to [4], wherein B contains two or more heteroatoms. [6] The polyorganosiloxane according to any one of [1] to [5], which is represented by the following formula (2): [ka] (In formula (2), R2 is a monovalent hydrocarbon group having 1 to 4 carbon atoms, and A, B, and n are defined as in formula (1).) [7] The polyorganosiloxane according to any one of [1] to [5], which is represented by the following formula (3): [ka] (In formula (3), R2 is a monovalent hydrocarbon group having 1 to 4 carbon atoms, and A, B, and n are defined as in formula (1).) [8] The polyorganosiloxane according to any one of [1] to [5], which is represented by the following formula (4): [ka] (In formula (4), R2 is a monovalent hydrocarbon group having 1 to 4 carbon atoms, m is an integer of 1 to 10, and A, B, and n are defined as in formula (1).) [9] The polyorganosiloxane according to [8], wherein m is 1 or 2.

[10] The polyorganosiloxane according to any one of [1] to [9], wherein A has 10 or less carbon atoms.

[11] A resin composition comprising the polyorganosiloxane according to any one of [1] to

[10] , a silicone resin, and a filler. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a polyorganosiloxane that exhibits excellent adsorption properties for various types of fillers and improves the dispersibility of the fillers. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Polyorganosiloxane] <Polyorganosiloxane represented by formula (1)> The polyorganosiloxane of the present invention has a structure represented by the following formula (1). [ka] (In formula (1), each R1 is independently a group represented by AB or a monovalent hydrocarbon group having 1 to 4 carbon atoms, At least one of the R1 is a group represented by AB, A is a divalent organic group bonded to a silicon atom, B is a conjugated ring structure of three or more conjugated rings that form a common conjugated system and contains at least one heteroatom; n is an integer greater than or equal to 1.)

[0013] The polyorganosiloxane of the present invention contains at least one heteroatom in B. Specifically, it is preferable that at least one of the atoms constituting the three or more conjugated rings in B is a heteroatom. Such a configuration of B can provide excellent adsorption to fillers, particularly oxide fillers described below. The reason for this is unclear, but it is presumed to be due to hydrogen bonding between the heteroatom and the hydroxyl group of the oxide. From the above viewpoints, B preferably contains two or more heteroatoms, and more preferably three or more heteroatoms. On the other hand, the number of heteroatoms in B is, for example, 10 or less, and preferably 5 or less.

[0014] The heteroatom contained in B is preferably at least one selected from a nitrogen atom, an oxygen atom, and a sulfur atom, and more preferably an oxygen atom or a nitrogen atom. When B contains these specific atoms as heteroatoms, the adsorption to the oxide filler is likely to be improved. When B contains two or more heteroatoms, the heteroatoms may be the same or at least one may be different, but it is preferable that they are the same.

[0015] Furthermore, when B contains two or more heteroatoms, the heteroatoms in B may be bonded directly or via a carbon atom, but are preferably bonded via a carbon atom. When the heteroatoms are bonded via a carbon atom, the polarization between the heteroatoms and the carbon atoms increases, strengthening the hydrogen bonding action of the heteroatoms and making it easier to improve the adsorption to the oxide filler. Furthermore, when B contains two or more heteroatoms, it is preferable that the heteroatoms are present in different rings.

[0016] As described above, B is a conjugated ring structure of three or more that constitute a common conjugated system. When B has such a structure, it can have excellent adsorption to fillers, particularly fillers having π electrons, as described below. Although the reason for this is unclear, it is presumed that π-π interactions occur between the π electrons of the carbon atoms that constitute the conjugated rings and the π electrons of the filler.

[0017] The number of conjugated ring structures is not particularly limited, but in practice it is, for example, 7 or less, preferably 6 or less, more preferably 5 or less, even more preferably 4 or less, and most preferably 3 conjugated ring structures. Conjugation refers to a molecular structure in which unsaturated bonds and single bonds are alternately connected, resulting in stabilization due to the interaction of p orbitals and delocalization of electrons (which are spread throughout the entire conjugated system).

[0018] B preferably contains a fused ring structure. When B contains a fused ring structure, the adsorption to the filler is improved, and the filler can be more easily dispersed in the resin. Furthermore, each ring constituting the fused ring structure is preferably at least one selected from five-membered rings and six-membered rings. Furthermore, the fused ring structure is preferably composed of three or more rings, more preferably composed of three to six rings, even more preferably composed of three to four rings, and even more preferably composed of three rings. In addition, in the fused ring structure, any carbon atom constituting the fused ring may have a bond for bonding to the above A, or a heteroatom may have a bond for bonding to the above A.

[0019] Examples of the fused ring structure include carbazole-substituted compounds, acridine-substituted compounds, dibenzofuran-substituted compounds, dibenzothiophene-substituted compounds, phenanthridine-substituted compounds, phenanthroline-substituted compounds, dibenzopyridine-substituted compounds, BTBT (benzo[B]benzo[4,5]thieno[2,3-d]thiophene)-substituted compounds, PDT (phenanthro[1,2-b:8,7-b']dithiophene)-substituted compounds, DBTTT (thieno[3,2-f]thieno[3',2':5,6][1]benzothieno[3,2-b][1]benzothiophene)-substituted compounds, and HATNA (diquinoxalino[2,3-a:2',3'-c]phenazine)-substituted compounds. Among these, carbazole-substituted compounds, dibenzofuran-substituted compounds, or dibenzothiophene-substituted compounds are preferred, carbazole-substituted compounds or dibenzofuran-substituted compounds are more preferred, and carbazole-substituted compounds are even more preferred.

[0020] Here, the term "substituted" means that the compound may have a substituent. For example, a carbazole substitution compound includes both carbazole and carbazole having a substituent. However, the carbazole referred to here is one in which, in addition to the substituent, one of the hydrogen atoms constituting the fused ring structure is substituted with a bond. The same applies to other substituted compounds. Furthermore, when the fused ring structure has a substituent, at least one of the hydrogen atoms constituting the fused ring structure is substituted with a substituent. Examples of the substituent include organic groups having 1 to 10 carbon atoms. More specifically, examples of the substituent include hydrocarbon groups such as alkyl groups, aryl groups such as phenyl groups, tolyl groups, and ethylphenyl groups, and aralkyl groups such as benzyl groups and phenethyl groups. Among these, the benzyl group is preferred. When the substituent is an alkyl group, the alkyl group may be linear or may have at least one of a branched structure and a cyclic structure.

[0021] In the above-mentioned substituted compound, the substituent may be bonded to at least any of the carbon atoms constituting the fused ring, or may be bonded to a heteroatom, but is preferably bonded to a heteroatom.

[0022] B may contain a non-fused ring structure. In this case, B preferably contains a structure in which three or more aromatic rings are directly bonded. In the non-fused ring structure, any carbon atom constituting the aromatic ring may have a bond bonding to the above A, or a heteroatom may have a bond bonding to the above A, but it is preferable that a carbon atom has a bond bonding to the above A. Examples of non-fused ring structures include terthiophene-substituted compounds, which are structures in which multiple thiophenes are linked by single bonds, terpyridine-substituted compounds, terfuran-substituted compounds, and 2,5-bis(4-biphenylyl)thiophene-substituted compounds. Among these, terthiophene-substituted compounds are preferred. When the non-fused ring structure is a substituted product, specific examples of the substituent that the substituted product has are the same as those described above. The substituent may be bonded to at least any of the carbon atoms constituting the aromatic ring, or may be bonded to a heteroatom, but it is preferable that the substituent be bonded to at least any of the carbon atoms constituting the aromatic ring.

[0023] In the present invention, B can be any of the above-mentioned structures without any particular limitation, but preferred examples of the structure of B are shown below. [ka] In formulas (5) to (9), * represents a bond to A. Furthermore, R3 in formula (6) is a hydrocarbon group having 1 to 4 carbon atoms. Examples of the hydrocarbon group having 1 to 4 carbon atoms include saturated aliphatic hydrocarbon groups such as methylene, ethylene, trimethylene, and tetramethylene, with the methylene group being preferred. The saturated aliphatic hydrocarbon group is preferably linear, but may be branched.

[0024] In formula (1), each R1 is independently a group represented by AB or a monovalent hydrocarbon group having 1 to 4 carbon atoms. At least one of the multiple R1's is a group represented by AB, where A is a divalent organic group and is bonded to the silicon atom of formula (1).

[0025] A is a divalent organic group bonded to the silicon atom of formula (1), preferably a divalent organic group having 11 or less carbon atoms, more preferably a divalent organic group having 10 or less carbon atoms. Thus, polyorganosiloxanes in which A has a certain number of carbon atoms or less are preferred because they have good compatibility with matrix resins such as silicone resins and tend to improve the dispersibility of fillers. In addition, the lower limit of the number of carbon atoms in A is not particularly limited, and may be 1, but 2 is preferred, 5 is more preferred, and 7 is even more preferred.

[0026] A may be a hydrocarbon group or may contain a heteroatom. Examples of the hydrocarbon group constituting A include saturated aliphatic hydrocarbon groups such as methylene, ethylene, trimethylene, and tetramethylene groups, and aromatic hydrocarbon groups such as phenylene groups. Among these, saturated aliphatic hydrocarbon groups having 1 to 4 carbon atoms are preferred, and ethylene groups are more preferred. The saturated aliphatic hydrocarbon group is preferably linear, but may be branched. When A is a hydrocarbon group, it is preferred that A be bonded to a heteroatom of B.

[0027] When A contains a heteroatom, it is preferable that at least one of the α-, β-, and γ-position atoms among the atoms constituting A is a heteroatom, and it is more preferable that at least one of the β- and γ-position atoms is a heteroatom. When at least one of the β- and γ-position atoms is a heteroatom, the distance from the heteroatom contained in B becomes a certain level or more, and the electronegativity of the heteroatom contained in B increases, which makes it easier to improve the adsorption to the oxide filler. Here, the α-atom is an atom that is bonded to a conjugated ring that B has (i.e., one of the three or more conjugated rings that B has) among the atoms that constitute A. The β-atom is an atom that is bonded to the α-atom among the atoms that constitute A. The γ-atom is an atom that is bonded to the β-atom but is other than the α-atom. In addition, A may be such that an atom other than the α-, β-, and γ-position atoms is a heteroatom, and in this case, A may be, for example, an oxygen-containing hydrocarbon group consisting of an alkylene group and an ester group.

[0028] The heteroatom contained in A is not particularly limited and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a boron atom. Among these, an oxygen atom is preferred from the viewpoint of effectively improving compatibility with resins. The heteroatom contained in A may be the same as or different from the heteroatom contained in B.

[0029] When A contains a heteroatom, A has a structural unit containing a heteroatom. Examples of the structural unit include ether, ester, amide, urethane, thioether, and thioester. Among them, from the viewpoint of improving the adsorption to the filler and improving the compatibility with the resin, ether or ester is preferred, ether is more preferred, and cyclic ether is particularly preferred. Note that the cyclic ether is an ether having a structure in which carbon of a cyclic hydrocarbon is substituted with oxygen.

[0030] Furthermore, A having a hetero atom preferably has a skeleton represented by the following formula (10-1) or formula (10-2), from the viewpoint of improving the adsorption to the filler and improving the compatibility with the resin. [ka] In formula (10-1), *1 and *2 are bonds, and R5 is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, preferably a hydrogen atom. Two R5s may be the same or different. R4 is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, preferably a hydrocarbon group having 1 to 4 carbon atoms, more preferably a hydrocarbon group having 1 to 3 carbon atoms, and even more preferably an ethyl group. R6 is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, preferably a hydrogen atom. The oxygen atom in formula (10-1) is the β- or γ-atom described above, preferably a β-atom. In formula (10-2), *3 and *4 are bonds. The oxygen atom having the bond *3 is the above-mentioned α-atom, β-atom, or γ-atom. Among the above, A preferably has a skeleton represented by formula (10-1).

[0031] Furthermore, from the viewpoint of improving the adsorption to the filler and compatibility with the resin, A preferably has any of the structures represented by the following formulas (11) to (16). [ka] In formulas (11) to (16), *5 is a bond bonded to the conjugated ring that B has, and *6 is a bond bonded to the silicon atom of formula (1).

[0032] Among the above formulas (11) to (16), A is more preferably a structure represented by formula (11) or formula (12), and even more preferably a structure represented by formula (11).

[0033] In formula (1), at least one R1 is the group represented by AB, and the remaining R1 are hydrocarbon groups having 1 to 4 carbon atoms. In formula (1), the number of groups represented by AB among the multiple R1 is, for example, 1 to 8, preferably 1 to 5, more preferably 1 to 4, and even more preferably 1 or 2, and the remainder are preferably monovalent hydrocarbon groups having 1 to 4 carbon atoms. When there are multiple groups represented by AB, the multiple groups represented by AB may be the same or different. Examples of the monovalent hydrocarbon group having 1 to 4 carbon atoms include alkyl groups such as methyl, ethyl, propyl, and butyl, and among these, at least one selected from methyl and butyl is preferred. The alkyl group is preferably linear, but may be branched. When there are multiple monovalent hydrocarbon groups having 1 to 4 carbon atoms, the multiple monovalent hydrocarbon groups having 1 to 4 carbon atoms may be the same or different. Furthermore, it is preferred that the terminal monovalent hydrocarbon group having 1 to 4 carbon atoms is any one of alkyl groups having 1 to 4 carbon atoms, and the other monovalent hydrocarbon groups having 1 to 4 carbon atoms are methyl groups.

[0034] In formula (1), n ​​represents the number of repetitions, and is an integer of 1 or greater. Although n is not particularly limited as long as it is an integer of 1 or greater, from the viewpoint of compatibility with resins, n is, for example, 500 or less, preferably 400 or less, more preferably 350 or less, and even more preferably 300 or less, and is, for example, 10 or more, preferably 20 or more, more preferably 30 or more, and even more preferably 50 or more.

[0035] The polyorganosiloxane having the structure represented by formula (1) may have the group represented by AB at one end, at both ends, on a side chain, at one end and on a side chain, or at both ends and on a side chain.

[0036] <Polyorganosiloxane represented by formula (2)> A polyorganosiloxane according to one embodiment of the present invention has a structure represented by the following formula (2): The polyorganosiloxane has a group represented by AB at one end. [ka] (In formula (2), each R2 is independently a monovalent hydrocarbon group having 1 to 4 carbon atoms, and A, B, and n are defined as in formula (1).) Examples of the monovalent hydrocarbon group having 1 to 4 carbon atoms include alkyl groups such as methyl, ethyl, propyl, and butyl, and among these, at least one selected from methyl and butyl is preferred. The alkyl group is preferably linear, but may be branched. Multiple R2s may be the same or different. In formula (2), A, B, and n have the same meanings as those in formula (1) and are as described above. The polyorganosiloxane represented by formula (2) has a group represented by AB at one end, which is preferable because it can easily improve the adsorption to the filler.

[0037] <Polyorganosiloxane represented by formula (3)> A polyorganosiloxane according to one embodiment of the present invention has a structure represented by the following formula (3): The polyorganosiloxane has groups represented by AB at both ends. [ka] (In formula (3), each R2 is independently a monovalent hydrocarbon group having 1 to 4 carbon atoms, and A, B, and n are defined as in formula (1).) R2 in formula (3) has the same meaning as R2 in formula (2), and A, B, and n have the same meanings as those in formula (1).

[0038] <Polyorganosiloxane represented by formula (4)> A polyorganosiloxane according to one embodiment of the present invention has a structure represented by the following formula (4): The polyorganosiloxane has a group represented by AB on a side chain. [ka] (In formula (4), R2 is a monovalent hydrocarbon group having 1 to 4 carbon atoms, m is an integer of 1 to 10, and A, B, and n are defined as in formula (1).) R2 in formula (4) has the same meaning as R2 in formula (2), and A, B, and n have the same meanings as those in formula (1). In formula (4), m is an integer of 1 or more and 10 or less, preferably an integer of 1 or more and 8 or less, more preferably an integer of 1 or more and 6 or less, even more preferably an integer of 1 or more and 4 or less, and still more preferably 1 or 2. When m is in this range, adsorption to the filler is improved and self-aggregation of polyorganosiloxanes is suppressed, which is preferable. The polyorganosiloxane represented by formula (4) may be a random polymer or a block polymer. More specifically, the unit shown in parentheses m and the unit shown in parentheses n may exist in the molecule in a block form or random form.

[0039] Of the above, the polyorganosiloxane used in the present invention preferably has a structure represented by the above formula (2) or (3), and more preferably has a structure represented by the above formula (2).

[0040] The polyorganosiloxane of the present invention preferably has a number average molecular weight of 5,000 or more, more preferably 10,000 or more, and even more preferably 15,000 or more. When the number average molecular weight of the polyorganosiloxane is equal to or greater than the above lower limit, the adsorption to the filler is superior. Furthermore, from the viewpoint of making the filler less likely to aggregate, the number average molecular weight of the polyorganosiloxane is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 40,000 or less. The number average molecular weight is a value determined by gel permeation chromatography (GPC) measurement and converted into polystyrene equivalent. The same applies to the number average molecular weight of the silicone resin described below.

[0041] <Method for producing polyorganosiloxane> The method for producing the polyorganosiloxane of the present invention is not particularly limited, but for example, the polyorganosiloxane may be produced by the method shown below. First, a commonly available polyorganosiloxane having functional groups (hereinafter also referred to as "polyorganosiloxane (X)") is prepared. Then, the polyorganosiloxane (X) is reacted with a compound having three or more conjugated ring structures (hereinafter also referred to as "heteroatom-containing conjugated ring structures") that form a common conjugated system and contain at least one heteroatom, and a functional group capable of reacting with the functional group possessed by the polyorganosiloxane (X). This reaction can produce the polyorganosiloxane of the present invention. For example, the polyorganosiloxane of the present invention can be produced by utilizing the acetalization reaction between an aldehyde and a diol, the hydrosilylation reaction between a hydrosilyl group and a carbon-carbon unsaturated bond, or the esterification reaction between an alcohol and a carboxyl group. More specifically, the polyorganosiloxane of the present invention can be produced by reacting a polyorganosiloxane (X) having a diol structure with a compound having an aldehyde group and a heteroatom-containing conjugated ring group. Alternatively, the polyorganosiloxane of the present invention can be produced by reacting a polyorganosiloxane (X) having a terminal and / or side chain hydrosilyl group with a compound having a group having a carbon-carbon unsaturated bond, such as a vinyl group, and a heteroatom-containing conjugated ring group.

[0042] [Resin composition] The present invention can also provide a resin composition containing the above-mentioned polyorganosiloxane, a filler, and a silicone resin. By containing the above-mentioned polyorganosiloxane, the resin composition of the present invention can be reduced in viscosity because the polyorganosiloxane and the filler are adsorbed and the filler is dispersed in the resin by the polyorganosiloxane. The resin composition will be described in detail below.

[0043] The content of polyorganosiloxane in the resin composition is, for example, 0.1 to 30 parts by mass, preferably 0.5 to 20 parts by mass, more preferably 1 to 10 parts by mass, relative to 100 parts by mass of filler. When the content of polyorganosiloxane is equal to or greater than the lower limit, adsorption to multiple types of fillers is exhibited, making it easier to disperse the filler in the resin. Furthermore, when the content of polyorganosiloxane is equal to or less than the upper limit, it is easier to exhibit effects commensurate with the content of polyorganosiloxane.

[0044] (filler) The resin composition of the present invention can be provided with excellent thermal conductivity by including a filler. The filler may include a filler having π electrons or a filler not having π electrons. The filler having π electrons preferably has a six-membered ring atomic structure as a constituent unit, and the six-membered ring atomic structure has π electrons. Specific examples of fillers having π electrons include boron nitride and carbon materials. When a filler having π electrons is used, the filler is adsorbed to the polyorganosiloxane through π-π interaction with the conjugated ring structure of the polyorganosiloxane, and can be dispersed in the silicone resin described below by the polyorganosiloxane.

[0045] Examples of boron nitride include hexagonal boron nitride, and more specifically, examples thereof include boron nitride nanotubes, boron nitride nanosheets, and hexagonal boron nitride particles. Boron nitride nanotubes are tubular materials formed from hexagonal boron nitride. The ideal structure of a boron nitride nanotube is one in which the planes of the six-membered ring network are parallel to the tube axis, forming either a single or multiple tube. Boron nitride nanotubes that form single tubes are called single-wall tubes, and those that form multiple tubes are called multi-wall tubes. Either single-wall tubes or multi-wall tubes may be used as boron nitride nanotubes, or a combination of these may be used.

[0046] The boron nitride nanotubes have, for example, an average diameter of 1 nm to 70 nm and an average length of 100 nm to 50 μm. By setting the average diameter and average length within the above ranges, the flexibility of the resin composition can be improved and the thermal conductivity of the resin composition can be easily increased. The average diameter of the boron nitride nanotubes is preferably 3 nm or more, more preferably 4 nm or more. The average diameter of the boron nitride nanotubes is preferably 10 nm or less, more preferably 8 nm or less. The average length of the boron nitride nanotubes is preferably 500 nm or more, more preferably 1 μm or more, and is preferably 20 μm or less, more preferably 8 μm or less, and even more preferably 5 μm or less.

[0047] The diameter of a boron nitride nanotube refers to the outer diameter in the case of a single-walled tube, and the outer diameter of the outermost tube in the case of a multi-walled tube. The diameter and length of boron nitride nanotubes can be measured in images obtained by observation using an electron microscope such as a TEM (transmission electron microscope), and the average diameter and average length can be determined by taking the arithmetic mean of any 50 nanotubes. The same applies to the diameter and length of carbon nanotubes, which will be described later.

[0048] Boron nitride nanosheets are formed from boron nitride and have an ultrathin two-dimensional sheet structure, such as a structure in which a single layer or multiple layers of hexagonal boron nitride are laminated. Boron nitride nanosheets with an average thickness of 20 nm or less are used, for example. From the viewpoint of improving thermal conductivity while making the resin composition sufficiently flexible, the average thickness of the boron nitride nanosheets is preferably less than 10 nm, more preferably 6 nm or less, and even more preferably 4 nm or less. The lower limit of the average thickness of the boron nitride nanosheets is not particularly limited, but is, for example, 1 nm. The size of the boron nitride nanosheets is not particularly limited, but the average longest diameter is, for example, 200 nm or more and 3 μm or less, and preferably 500 nm or more and 2 μm or less. The thickness and maximum diameter of the boron nitride nanosheets can be measured in images obtained by observation using an electron microscope such as a TEM (transmission electron microscope), and the average thickness and maximum diameter of each boron nitride nanosheet can be determined by taking the arithmetic mean of any 50 images in the electron microscope image. The same applies to the maximum diameter and thickness of the carbon nanosheets described below.

[0049] The hexagonal boron nitride particles are particulate boron nitride particles other than boron nitride nanosheets and boron nitride nanotubes, and are not particularly limited in shape, and may be boron nitride particles of any shape such as scale-like, spherical, polygonal, irregular, etc. They may also be aggregated particles formed by aggregation of multiple primary particles. The primary particle size of the hexagonal boron nitride particles is not particularly limited and may be nano-sized or micro-sized. For example, the average primary particle size of the hexagonal boron nitride particles may be, for example, 5 nm to 100 μm, preferably 10 nm to 50 μm, and more preferably 0.1 μm to 40 μm. The particle size of the aggregated particles is not particularly limited either, and the average particle size of the aggregated particles is, for example, 0.1 μm to 250 μm, more preferably 0.5 μm to 200 μm, and even more preferably 1 μm to 150 μm. The primary particle size and aggregate particle size of hexagonal boron nitride particles can be determined by measuring the maximum particle diameter in an image obtained by observation using an electron microscope such as a TEM (transmission electron microscope) or an SEM (scanning electron microscope). The average particle size, such as the average primary particle size, can be determined by taking the arithmetic mean of the maximum diameters of any 50 particles. The same applies to other fillers, such as graphite particles, which will be described later.

[0050] The carbon material is not particularly limited, but examples thereof include carbon fiber, carbon nanotube, carbon nanosheet, graphite, and graphene.

[0051] The carbon fiber is preferably a graphitized carbon fiber. In the graphitized carbon fiber, the crystal planes of graphite (i.e., the planes of the six-membered ring network) are connected in the fiber axis direction, and the graphitized carbon fiber has high thermal conductivity in the fiber axis direction. The graphitized carbon fiber preferably has a high degree of graphitization. The fiber diameter of the graphitized carbon fiber is not particularly limited, but for example, the average diameter is 1 μm or more and 30 μm or less, and preferably 5 μm or more and 20 μm or less. When the fiber diameter is within the above range, industrial production is easy, and the thermal conductivity of the resin composition is easily increased. As described above, the average fiber length of the carbon fibers is preferably 10 μm or more and 600 μm or less, more preferably 15 μm or more and 500 μm or less, and even more preferably 20 μm or more and 300 μm or less. The average diameter and average fiber length of the carbon fibers may be measured in an image obtained by observation using an electron microscope such as a TEM (transmission electron microscope) or an SEM (scanning electron microscope), and the arithmetic mean of the diameters and fiber lengths of any 50 carbon fibers may be used as the average diameter and average fiber length.

[0052] Carbon nanotubes are substances with a structure in which graphite sheets with a hexagonal mesh-like arrangement of carbon atoms are rolled up into a cylinder. Those rolled up in one layer are called single-wall carbon nanotubes, and those rolled up in multiple layers are called multi-wall carbon nanotubes. In the present invention, the type of carbon nanotube is not particularly limited, and may be any of single-wall carbon nanotubes, multi-wall carbon nanotubes, and a combination of these. The average diameter of the carbon nanotubes is preferably 1 nm or more and 100 nm or less, more preferably 2 nm or more and 15 nm or less, and the average length of the carbon nanotubes is preferably 0.1 μm or more and 1000 μm or less, more preferably 10 μm or more and 500 μm or less.

[0053] Carbon nanosheets have a structure in which hexagonal mesh-like carbon atom arrangements are arranged along the surface direction, and have an ultra-thin two-dimensional sheet structure, for example, a structure in which a single layer or multiple layers of hexagonal mesh-like carbon atom arrangements are stacked. The carbon nanosheet has an average thickness of, for example, 20 nm or less, preferably 10 nm or less. The lower limit of the average thickness of the carbon nanosheet is not particularly limited, but is, for example, 0.7 nm. The size of the carbon nanosheet is not particularly limited, but is, for example, 0.2 μm to 3 μm, preferably 5 μm to 2.5 μm, inclusive ...

[0054] Examples of graphite include graphite particles. The graphite particles are particles other than the above-mentioned carbon fibers, carbon nanotubes, and carbon nanosheets, and are not particularly limited in shape, and may be graphite particles of any shape, such as flaky, spherical, polygonal, or irregular. They may also be aggregated particles formed by aggregating multiple primary particles. For example, the average primary particle size of the graphite particles may be, for example, 5 nm or more and 100 μm or less, preferably 10 nm or more and 50 μm or less, and more preferably 0.1 μm or more and 40 μm or less. The particle size of the aggregated particles is not particularly limited either, and the average particle size of the aggregated particles is, for example, 0.1 μm to 250 μm, more preferably 0.5 μm to 200 μm, and even more preferably 1 μm to 150 μm.

[0055] Graphene has planar layers in a hexagonal mesh pattern and can be obtained, for example, by exfoliating graphite, which has a layered structure in which the planar layers in a hexagonal mesh pattern are stacked by van der Waals forces. The average thickness of graphene is, for example, 3 nm to 100 nm, preferably 7 nm to 50 nm. The average thickness can be measured, for example, in an image obtained by observation with a TEM (transmission electron microscope), and can be calculated as the arithmetic average of any 50 images in the electron microscope image.

[0056] In the present invention, when a filler having π electrons is used as the filler, it is more preferable that the filler contains at least one selected from the group consisting of boron nitride, carbon nanotubes, carbon fibers, graphite, and graphene. Among fillers having π electrons, the use of these fillers makes it easier to improve the thermal conductivity of the resin composition. In addition, these fillers have excellent adsorption properties with the conjugated ring structure of polyorganosiloxane, making it easier to incorporate the filler in a state where it is properly dispersed in the resin composition.

[0057] Examples of fillers that do not have π electrons include oxides, nitrides, carbides, and metal hydroxides. Examples of oxides include metal oxides such as iron oxide, zinc oxide, aluminum oxide such as alumina, magnesium oxide, titanium oxide, cerium oxide, and zirconium oxide, and oxides other than metal oxides such as silicon oxide (silica). Examples of nitrides include metal nitrides such as aluminum nitride, gallium nitride, chromium nitride, tungsten nitride, magnesium nitride, molybdenum nitride, and lithium nitride, and nitrides other than metal nitrides such as silicon nitride. Examples of carbides include metal carbides such as aluminum carbide, titanium carbide, and tungsten carbide, and carbides other than metal carbides such as silicon carbide and boron carbide. Examples of metal hydroxides include aluminum hydroxide, calcium hydroxide, and magnesium hydroxide.

[0058] When a filler without π electrons is used, it is preferable to use an oxide, more preferably a metal oxide, and even more preferably aluminum oxide. When an oxide is used as a filler, polyorganosiloxane is adsorbed to the filler surface by hydrogen bonding of heteroatoms, making it easier to incorporate the filler in a state where it is properly dispersed in the resin composition. The average primary particle size of the filler having no π electrons is not particularly limited, but is preferably 0.1 μm or more and 100 μm or less, more preferably 0.5 μm or more and 50 μm or less, and even more preferably 0.5 μm or more and 15 μm or less. The above fillers may be used alone or in combination of two or more.

[0059] The content of the filler in the resin composition is preferably 50% by mass or more and 95% by mass or less, based on the total amount of the resin composition. By setting the content of the filler within the above range, it is possible to improve the thermal conductivity while imparting a certain degree of flexibility to the resin composition. The content of the filler in the resin composition is more preferably 60% by mass or more and 90% by mass or less, and even more preferably 70% by mass or more and 85% by mass or less.

[0060] The resin composition preferably contains at least one of a filler having π electrons and an oxide. By containing at least one of these fillers, the polyorganosiloxane having the structure represented by the above formula (1) is appropriately adsorbed to the filler, thereby improving the dispersibility of the filler. Furthermore, from the viewpoint of making it easier to obtain thermal conductivity commensurate with the production cost, the resin composition preferably contains a combination of a filler having π electrons and a filler not having π electrons. Among these, from the viewpoint of further improving the dispersibility of the filler, it is more preferable that the resin composition contains a filler having π electrons and an oxide, and in particular, it is even more preferable that the resin composition contains both a carbon material and an oxide.

[0061] The content of the filler having π electrons in the resin composition is preferably 3 to 30 mass %, more preferably 5 to 20 mass %, and even more preferably 8 to 15 mass %, based on the total amount of fillers. The content of the oxide as a filler in the resin composition is preferably 40 to 97 mass %, more preferably 60 to 95 mass %, and even more preferably 70 to 92 mass %, based on the total amount of fillers.

[0062] (silicone resin) The silicone resin used may be different from the polyorganosiloxane described above. The silicone resin may serve as a matrix resin in the resin composition, and the filler may be dispersed in the silicone resin and held by the silicone resin.

[0063] Silicone resins are typically compounds that do not have three or more conjugated ring structures that form a common conjugated system. The three or more conjugated ring structures that form a common conjugated system here have the same meaning as "B" described in formula (1). The silicone resin may be a curable silicone resin, which may be either a condensation curable silicone resin or an addition reaction curable silicone resin, with addition reaction curable silicone resin being preferred.

[0064] The silicone resin may have a branched or linear structure, and specifically includes organopolysiloxanes having addition reactive groups. The addition reactive groups refer to functional groups that react by addition reaction, and representative examples include alkenyl groups, methacryloyl groups, acryloyl groups, and hydrosilyl groups. The organopolysiloxanes having addition reactive groups are preferably used as addition reaction curable silicone resins. Preferable examples of organopolysiloxanes having addition reactive groups include organopolysiloxanes having alkenyl groups and organopolysiloxanes having hydrosilyl groups.

[0065] The organopolysiloxane having an alkenyl group is an addition reaction curable silicone resin that cures when used in combination with an organopolysiloxane having a hydrosilyl group. The organopolysiloxane having an alkenyl group may have one or more alkenyl groups in the molecule, and preferably has two or more alkenyl groups. In the organopolysiloxane, the alkenyl group may be contained at either the terminal or the middle of the molecular chain of the polysiloxane structure, or may be contained at both the terminal and the middle. However, it is preferable to contain the alkenyl group at least at the terminal, and it is more preferable to contain the alkenyl group at both terminals of the molecular chain consisting of the polysiloxane structure. The alkenyl group is not particularly limited, but examples thereof include those having 2 to 8 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, and octenyl groups, with vinyl being preferred from the standpoints of ease of synthesis and reactivity. The alkenyl group is preferably an alkenyl group directly bonded to a silicon atom.

[0066] In organopolysiloxanes having alkenyl groups, examples of residual groups bonded to silicon atoms other than alkenyl groups include alkyl groups having about 1 to 18 carbon atoms, such as methyl, ethyl, propyl, butyl, hexyl, and dodecyl groups; aryl groups having about 6 to 12 carbon atoms, such as phenyl groups; and aralkyl groups having about 7 to 18 carbon atoms, such as 2-phenylethyl and 2-phenylpropyl groups. Further specific examples include substituted hydrocarbon groups, such as chloromethyl and 3,3,3-trifluoropropyl groups. Of these, methyl groups are preferred from the viewpoint of ease of synthesis. Furthermore, of the remaining groups bonded to silicon atoms, methyl groups preferably account for 80 mol % or more, more preferably 90 mol % or more, and even more preferably 100 mol %. Organopolysiloxanes having alkenyl groups typically do not have hydrogen atoms as the remaining groups bonded to silicon atoms, i.e., the silicone resin does not contain hydrosilyl groups. Specific examples of organopolysiloxanes having alkenyl groups include organopolysiloxanes having vinyl groups at both ends, such as polydimethylsiloxane having vinyl groups at both ends, polyphenylmethylsiloxane having vinyl groups at both ends, a copolymer of dimethylsiloxane having vinyl groups at both ends and diphenylsiloxane, a copolymer of dimethylsiloxane having vinyl groups at both ends and phenylmethylsiloxane, and a copolymer of dimethylsiloxane having vinyl groups at both ends and diethylsiloxane.

[0067] The organopolysiloxane having a hydrosilyl group is an addition reaction curable silicone resin that cures when used in combination with the above-mentioned organopolysiloxane having an alkenyl group. The organopolysiloxane having a hydrosilyl group preferably has one or more hydrosilyl groups in the molecule. The hydrosilyl group may be contained either at the end of the molecular chain of the polysiloxane structure or in the middle of the molecular chain, or may be contained at both the end and the middle, but it is preferable to contain the hydrosilyl group at least at the end, and more preferably at both ends of the molecular chain of the polysiloxane structure. In organopolysiloxanes having hydrosilyl groups, specific examples of the residual groups bonded to silicon atoms other than hydrosilyl groups are as described for organopolysiloxanes having alkenyl groups, and therefore their explanation will be omitted.Moreover, as the residual group, methyl groups are preferred, and the preferred proportion thereof is as described for organopolysiloxanes having alkenyl groups.Note that organopolysiloxanes having hydrosilyl groups typically do not contain alkenyl groups.

[0068] Examples of organopolysiloxanes having hydrosilyl groups include methylhydrosiloxane-dimethylsiloxane copolymers, polymethylhydrosiloxanes, polyethylhydrosiloxanes, methylhydrosiloxane-phenylmethylsiloxane copolymers, etc. These may or may not contain hydrosilyl groups at the terminals.

[0069] The organopolysiloxane may be an organopolysiloxane that does not have an addition reaction group, such as silicone oil. Examples of silicone oils include straight silicone oils such as dimethylsilicone oil (polydimethylsiloxane), polyphenylmethylsiloxane, dimethylsiloxane-diphenylsiloxane copolymer, and phenylmethylsilicone oils such as dimethylsiloxane-phenylmethylsiloxane, as well as non-reactive modified silicone oils in which a non-reactive organic group has been introduced into a main chain having a polysiloxane structure, a side chain bonded to the main chain, or the end of the main chain. A non-reactive organic group is an organic group that does not have an addition reaction group. Examples of non-reactive modified silicone oils include polyether-modified silicone oil, aralkyl-modified silicone oil, fluoroalkyl-modified silicone oil, long-chain alkyl-modified silicone oil, higher fatty acid ester-modified silicone oil, higher fatty acid amide-modified silicone oil, and phenyl-modified silicone oil. Among the above, straight silicone oil is preferred, and among straight silicone oils, dimethylsilicone oil is more preferred.

[0070] The organopolysiloxane may be other than those mentioned above, and may be an organopolysiloxane having an alkoxy group or an organopolysiloxane having a silanol group. The silicone resin may be used alone or in combination of two or more of the above-mentioned resins.

[0071] The silicone resin preferably has a number-average molecular weight of 5,000 or more and 50,000 or less. When the number-average molecular weight is within the above range, the resin composition can be easily formed into a heat-dissipating material, since it can maintain a constant shape after coating or application while improving the coatability and workability of the resin composition. Furthermore, it is easy to properly disperse and incorporate a large amount of filler while ensuring the flexibility of the resin composition, and it also becomes easy to improve thermal conductivity. The number-average molecular weight is more preferably 7,000 or more and 40,000 or less, and even more preferably 10,000 or more and 30,000 or less.

[0072] The silicone resin is preferably liquid at room temperature (25°C) and normal pressure (1 atmosphere). Being liquid, the silicone resin facilitates the coating and application properties of the resin composition. Furthermore, the resin composition maintains a low viscosity, allowing the filler to be properly dispersed and incorporated in large quantities.

[0073] The resin composition may be curable or non-curable. In the case of a curable type, it may be a one-component curable type or a two-component curable type. In the case of a one-component curable type, the silicone resin may contain a silicone resin as a main component and a silicone resin as a curing agent. More specifically, it is preferable to contain an organopolysiloxane having an alkenyl group and an organopolysiloxane having a hydrosilyl group.

[0074] In the case of a two-component curing type, the resin composition may constitute one of the two components. Therefore, the resin composition may contain either a silicone resin as a base component or a silicone resin as a curing agent. More specifically, the resin composition may contain either an organopolysiloxane having an alkenyl group or an organopolysiloxane having a hydrosilyl group. However, even in the case of a two-component curing type, the silicone resin may contain an organopolysiloxane having a hydrosilyl group or an organopolysiloxane having an alkenyl group, in addition to an organopolysiloxane having an alkenyl group or an organopolysiloxane having a hydrosilyl group, as long as curing does not proceed. In the case of a two-component curing type, the resin composition of the present invention may be a mixture of the first and second components.

[0075] In the case of a two-component type, it is preferable that both the first and second components are made of a resin composition containing a polyorganosiloxane, a filler, and a silicone resin. It is also preferable that the first component contains an organopolysiloxane having an alkenyl group, and the second component contains an organopolysiloxane having a hydrosilyl group.

[0076] Furthermore, the curable resin composition may contain the above-described non-reactive organopolysiloxane as the silicone resin, and may contain, for example, an organopolysiloxane having no addition reactive group in addition to the above-described organopolysiloxane having an alkenyl group or organopolysiloxane having a hydrosilyl group.

[0077] The resin composition may also be a non-curable resin composition, and in such a case, silicone oil, for example, may be used as the silicone resin. In addition, a part of the silicone resin may be a by-product produced in the process of producing the above-mentioned polyorganosiloxane. When the silicone resin contains a by-product produced in the process of producing the polyorganosiloxane, it is preferable that the silicone resin further contains components other than the by-product.

[0078] The content of the silicone resin in the resin composition is preferably 3% by mass or more and 45% by mass or less, based on 100% by mass of the resin composition. By setting the content of the silicone resin within the above range, the filler can be properly held by the silicone resin. This makes it easier to improve the thermal conductivity while imparting a certain degree of flexibility to the resin composition. The content of the silicone resin in the resin composition is more preferably 5% by mass or more and 35% by mass or less, and even more preferably 10% by mass or more and 25% by mass or less.

[0079] (additives) The resin composition of the present invention may contain additives other than the polyorganosiloxane, filler, and silicone resin described above, as needed, to the extent that the effects of the present invention are not impaired. For example, when the silicone resin is a curable silicone resin, the resin composition may typically contain a curing catalyst. When the silicone resin is an addition reaction type silicone resin, examples of the curing catalyst include platinum-based catalysts, palladium-based catalysts, and rhodium-based catalysts. The curing catalyst is a catalyst for curing the base resin and the curing agent. The amount of the curing catalyst added is typically 0.1 to 200 ppm, preferably 0.5 to 100 ppm, based on the mass of the silicone resin. In addition to the curing catalyst, additives such as an alkoxysilane compound, an antioxidant, a heat stabilizer, a colorant, a flame retardant, an antistatic agent, etc. may be blended. The other components may be used alone or in combination of two or more.

[0080] [Physical properties and applications of resin compositions] The resin composition of the present invention preferably has a piercing load of 100 mN or less, more preferably 90 mN or less, and even more preferably 80 mN or less. When the piercing load is as low as described above, the adsorption between the polyorganosiloxane and the filler is excellent, and the polyorganosiloxane can be said to be able to sufficiently disperse the filler in the resin. The piercing load is not particularly limited in its lower limit, but may be, for example, 1 mN or more, or 2 mN or more. The piercing load is measured by the method described in the examples below.

[0081] The resin composition of the present invention can be suitably used as a heat-dissipating material, such as a heat-dissipating silicone grease or a heat-dissipating silicone sheet. The resin composition of the present invention can also be used in electronic devices to dissipate heat from various electronic components. Specifically, the resin composition of the present invention, in a cured state as needed, can be placed between an electronic component, such as a semiconductor element, and a heat sink to effectively dissipate heat generated from the electronic component. [Example]

[0082] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0083] [Piercing load] The piercing load of the resin composition was measured by the following method. The resin composition was degassed, and 30 g of the degassed thermally conductive composition was introduced into a cylindrical container with a diameter of 25 mm. Next, a piercing rod (rod diameter: 1.8 mm) with a disk-shaped member with a diameter of 2 mm and a thickness of 1 mm at its tip was pressed against the thermally conductive composition introduced into the container from the tip side of the piercing rod at a speed (piercing speed) of 10 mm / min, and the load (mN) was measured when the tip of the piercing rod reached a depth of 2 mm from the liquid surface. Based on the measured load, evaluation was performed according to the following evaluation criteria. The piercing rod was made of stainless steel. Measurements were performed at 25°C, and load measurements were performed using an IMADA "ZTS-5N." Furthermore, the adsorption of the filler was evaluated based on the measured value of the piercing load. The evaluation criteria were as follows: AA: 80mN or less A: More than 80mN and less than 90mN B: More than 90mN and less than 100mN C: More than 100mN

[0084] [Raw materials used] The raw materials used in the examples and comparative examples are as follows. (filler) Graphite: π electrons, graphite powder, average particle size 10 μm, flake shape Alumina: No π electrons, oxide powder, average particle size 3.5 μm, spherical

[0085] (Polyorganosiloxane) The polyorganosiloxanes used in the examples and comparative examples were those synthesized in the following Synthesis Examples 1 to 8 and Comparative Synthesis Examples 1 to 6, respectively. <Synthesis Example 1> 90 g of an organosiloxane compound (n=70) having a hydrosilyl group represented by formula (17), 5.8 g of 9-vinylcarbazole as a monomer, 90 g of toluene as a solvent, and a catalytic amount of platinum catalyst (125 mass ppm relative to the organosiloxane compound) were reacted under a nitrogen atmosphere at 60°C for 17 hours. After the reaction, the mixture was concentrated to remove the toluene, and the concentrated residue was purified by silica gel column chromatography to obtain polyorganosiloxane (polyorganosiloxane (1)) of Synthesis Example 1. The reaction formula is as follows: 1 The progress of the following reaction was confirmed by H NMR measurement. The NMR measurement device used was a JEOL "ECX-400," and the measurement was carried out under the conditions of a sample concentration of 1 wt % using deuterated chloroform as the solvent, 25°C, a measurement frequency of 400 MHz, and 8 accumulations. The progress of the reaction was also confirmed for other synthesis examples and comparative synthesis examples. 1 This was confirmed by 1 H NMR measurement. [ka]

[0086] <Synthesis Example 2> 90 g of an organosiloxane compound (n = 210) having a 1,3-diol group represented by formula (18), 2.6 g of 9-benzylcarbazole-3-carboxyaldehyde as a monomer, 50 g of toluene as a solvent, and 0.6 g of a catalyst ("Amberlyst 15 dry" manufactured by Organo Corporation) were reacted in a nitrogen atmosphere at 100 °C for 24 hours. After the reaction, the catalyst was removed by filtration through a 5.0 μm PTFE filter, and the filtrate was concentrated using a rotary evaporator and a vacuum dryer to remove the toluene. The concentrated residue was purified by silica gel column chromatography to obtain the polyorganosiloxane (polyorganosiloxane (2)) of Synthesis Example 2. The reaction formula is as follows: [ka]

[0087] <Synthesis Example 3> A polyorganosiloxane (polyorganosiloxane (3)) of Synthesis Example 3 was obtained in the same manner as in Synthesis Example 2, except that the monomer was changed to 1.8 g of dibenzofuran-2-carboxyaldehyde. The reaction formula is as follows: [ka]

[0088] <Synthesis Example 4> The polyorganosiloxane of Synthesis Example 4 (polyorganosiloxane (4)) was obtained in the same manner as in Synthesis Example 1, except that the organosiloxane compound of formula (17) was replaced with an organosiloxane compound (n = 70) having a hydrosilyl group represented by formula (19) and the amounts of 9-vinylcarbazole as a monomer and toluene as a solvent were each doubled. The reaction formula is as follows: [ka]

[0089] <Synthesis Example 5> The polyorganosiloxane (polyorganosiloxane (5)) of Synthesis Example 5 was obtained in the same manner as in Synthesis Example 1, except that the organosiloxane compound of formula (17) was replaced with an organosiloxane compound (n=70) having a hydrosilyl group represented by formula (20). The reaction formula is as follows: [ka]

[0090] <Synthesis Example 6> The polyorganosiloxane of Synthesis Example 6 (polyorganosiloxane (6)) was obtained in the same manner as in Synthesis Example 1, except that the organosiloxane compound of formula (20) was changed to an organosiloxane compound (n = 70) having a hydrosilyl group represented by formula (21) and the amounts of 9-vinylcarbazole as a monomer and toluene as a solvent were each changed to four times the amount. The reaction formula is as follows. [ka]

[0091] <Synthesis Example 7> A polyorganosiloxane (polyorganosiloxane (7)) of Synthesis Example 7 was obtained in the same manner as in Synthesis Example 2, except that the monomer was changed to 1.9 g of dibenzothiophene-2-carboxaldehyde. The reaction formula is as follows: [ka]

[0092] <Synthesis Example 8> Polyorganosiloxane (polyorganosiloxane (8)) of Synthesis Example 8 was obtained in the same manner as in Synthesis Example 2, except that the monomer was changed to 2.5 g of 2,2':5'2''-terthiophene-5-carboxyaldehyde. The reaction formula is as follows: [ka]

[0093] <Comparative Synthesis Example 1> 50 g of the organosiloxane compound (n = 70) represented by formula (19), 3 g of allylamine as a monomer, 50 g of toluene as a solvent, and 125 mass ppm of platinum catalyst (relative to the organopolysiloxane compound) were reacted under a nitrogen atmosphere at 60 ° C for 17 hours. After the reaction, the toluene was removed by concentration, and the concentrated residue was purified by silica gel column chromatography to obtain the polyorganosiloxane of Comparative Synthesis Example 1 (polyorganosiloxane (9)). The reaction formula is as follows: [ka]

[0094] <Comparative Synthesis Example 2> A polyorganosiloxane (polyorganosiloxane (10)) of Comparative Synthesis Example 2 was obtained in the same manner as in Synthesis Example 2, except that the monomer was changed to indole-3-carboxaldehyde. The reaction formula is as follows: [ka]

[0095] <Comparative Synthesis Example 3> The polyorganosiloxane (polyorganosiloxane (11)) of Comparative Synthesis Example 3 was obtained in the same manner as in Synthesis Example 2, except that the monomer was changed to 1.9 g of 9-anthracenecarboxaldehyde and the organosiloxane compound of formula (18) was changed to 30 g of a compound in which n = 70. The reaction formula is as follows: [ka]

[0096] <Comparative Synthesis Example 4> Polyorganosiloxane (polyorganosiloxane (12)) of Comparative Synthesis Example 4 was obtained in the same manner as in Synthesis Example 4, except that the monomer was changed to 16.6 g of 9-anthrylmethyl methacrylate. The reaction formula is as follows: [ka]

[0097] <Comparative Synthesis Example 5> A polyorganosiloxane (polyorganosiloxane (13)) of Comparative Synthesis Example 5 was obtained in the same manner as in Synthesis Example 5, except that the monomer was changed to 8.3 g of 9-anthrylmethyl methacrylate. The reaction formula is as follows: [ka]

[0098] <Comparative Synthesis Example 6> Polyorganosiloxane (polyorganosiloxane (14)) of Comparative Synthesis Example 6 was obtained in the same manner as in Synthesis Example 6, except that the monomer was changed to 33.2 g of 9-anthrylmethyl methacrylate. The reaction formula is as follows: [ka]

[0099] (resin) Polydimethylsiloxane with a number average molecular weight of 20,000

[0100] [Examples 1 to 8, Comparative Examples 1 to 6] A resin composition was obtained by mixing 100 parts by mass of resin, 47 parts by mass of graphite, 362 parts by mass of alumina, and 6 parts by mass of polyorganosiloxane. The puncture load of the obtained resin composition was measured, and the filler adsorption was evaluated based on the measured value. The evaluation results are shown in Table 1. Table 1 also shows the polyorganosiloxanes used in each of the examples and comparative examples and their details.

[0101] [Table 1]

[0102] As is clear from the above examples, when polyorganosiloxanes satisfying the requirements of the present invention are blended into a resin composition, the piercing load of the composition is low and it was seen that they exhibited excellent adsorption to both graphite and alumina fillers.

[0103] In contrast, the resin compositions prepared in Comparative Examples 1 and 2 resulted in high piercing loads. This is thought to be because the polyorganosiloxanes used in Comparative Examples 1 and 2 had an insufficient number of conjugated rings in B in the above formula (1), resulting in insufficient adsorption to graphite. In addition, the resin composition prepared in Comparative Example 2 did not have a heteroatom in B in the above formula (1), resulting in insufficient adsorption to alumina, which is also thought to be the reason for the high piercing load.

[0104] The resin compositions prepared in Comparative Examples 3 to 6 also had high piercing loads. This is thought to be because the polyorganosiloxanes used in Comparative Examples 3 to 6 did not have a heteroatom in B in the above formula (1), and therefore had insufficient adsorption to alumina.

Claims

1. A polyorganosiloxane having a structure represented by the following formula (1): 【Chemistry 1】 (In formula (1), R １ are each independently a group represented by A-B or a monovalent hydrocarbon group having 1 to 4 carbon atoms, The R １ At least one R １ is the group represented by A-B, A is a divalent organic group bonded to a silicon atom, B is a conjugated ring structure of three or more conjugated rings that form a common conjugated system and contains at least one heteroatom; n is an integer of 1 or more.

2. 2. The polyorganosiloxane of claim 1, wherein B comprises a fused ring structure.

3. The polyorganosiloxane according to claim 1 or 2, wherein B comprises a structure in which three or more aromatic rings are directly bonded.

4. The polyorganosiloxane according to claim 1 or 2, wherein the heteroatom is at least one selected from a nitrogen atom, an oxygen atom, and a sulfur atom.

5. 3. The polyorganosiloxane of claim 1, wherein B contains two or more heteroatoms.

6. The polyorganosiloxane according to claim 1 or 2, represented by the following formula (2): 【Chemistry 2】 (In formula (2), R ２ is a monovalent hydrocarbon group having 1 to 4 carbon atoms, and A, B, and n are defined as in formula (1).

7. The polyorganosiloxane according to claim 1 or 2, represented by the following formula (3): 【Transformation 3】 (In formula (3), R ２ is a monovalent hydrocarbon group having 1 to 4 carbon atoms, and A, B, and n are defined as in formula (1).

8. The polyorganosiloxane according to claim 1 or 2, represented by the following formula (4): 【Chemistry 4】 (In formula (4), R ２ is a monovalent hydrocarbon group having 1 to 4 carbon atoms, m is an integer of 1 or more and 10 or less, and A, B, and n are defined as in formula (1).

9. The polyorganosiloxane according to claim 8, wherein m is 1 or 2.

10. The polyorganosiloxane according to claim 1 or 2, wherein A has 10 or less carbon atoms.

11. A resin composition comprising the polyorganosiloxane according to claim 1 or 2, a silicone resin, and a filler.

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