Silicone resin composition and cured product thereof

Abstract

Provided is a silicone resin composition which can be suitably used as a damping material, a potting material, or a heat dissipation material, and which is capable of forming a cured product having high deformation followability due to having excellent ductility. The silicone resin composition comprises a cyclic siloxane (A) having a first functional group, a linear polysiloxane (B) having a second functional group capable of performing an addition reaction with the first functional group at both ends of a molecular chain, and a linear polymer (C) having a first functional group at both ends of a molecular chain, and a photopolymerization initiator or a thermocuring catalyst (D) that initiates or promotes an addition reaction between the first functional group and the second functional group, the cyclic siloxane (A) being a cyclic siloxane represented by general formulae (1) to (3). The ratio of the number of second functional groups contained in the linear polysiloxane (B) to the total number of first functional groups contained in the cyclic siloxane (A) and the linear polymer (C) is 0.4-1.9, and the ratio of the amount of substance of the linear polymer (C) to the amount of substance of the linear polysiloxane (B) is 0.4 or more and less than 0.6. In general formula (1), general formula (2), and general formula (3), Ra or SiRa in which Ra is bonded to a silicon atom of a siloxane chain represents a first functional group, Rb independently represents an alkyl group or a phenyl group, m represents an integer of 3-5, in general formula (2) and general formula (3), n represents an integer of 1-1000, and in general formula (3), Y represents an alkylene group. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a silicone resin composition curable by light such as ultraviolet light or heat, and more particularly, to a silicone resin composition capable of forming a cured product (such as silicone gel or silicone rubber) having excellent ductility and a cured product thereof. Background Art

[0002] Silicone viscoelastic materials such as silicone gel and silicone rubber have various properties such as softness, elongation, heat resistance, light resistance, or light transmittance, and are therefore used in various fields such as electronic devices, construction, and medical fields. In recent years, with the diversification of usage, further improvement of the properties of silicone viscoelastic materials has been required. In particular, in applications such as sealing materials for electrical and electronic components, coating materials for sensors, potting materials, damping materials, heat dissipation materials, and optical adhesives (OCR, OCA), a silicone viscoelastic material with excellent deformation followability is required to cope with stronger impacts and larger vibrations. Therefore, the demand for a silicone resin composition for forming a silicone viscoelastic material having high deformation followability, that is, excellent ductility, is increasing.

[0003] Therefore, in order to improve the ductility of the cured product of the silicone resin composition, Patent Document 1 proposes a UV-curable silicone resin composition containing a specific linear organopolysiloxane (B) having an aliphatic unsaturated group, an organopolysiloxane (A2) containing more than two mercaptoalkyl groups bonded to silicon atoms, and a specific organopolysiloxane (A1) having dithiols at both ends, and setting the ratio of the number of mercapto groups in the component (A1 + A2) to the number of aliphatic unsaturated groups in the component (B) to 1 to 3.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 6426023 Gazette Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] However, the silicone resin composition of Patent Document 1 was proposed as a resin between the protective part and the image display part in an image display device, and was not envisioned for use as a damping material, potting material, or heat dissipation material. Therefore, when used as a damping material, potting material, or heat dissipation material, in order to adjust the viscosity in the uncured state or improve the heat dissipation performance, it is necessary to contain a solid filler such as a functional filler in the silicone resin composition, but this may cause the cured product to become hard and the ductility to decrease.

[0009] Accordingly, the present invention has been accomplished in view of the above problems, and an object thereof is to provide a silicone resin composition that can be suitably used as a damping material, a potting material, or a heat dissipation material and can form a cured product having high deformation followability due to excellent ductility.

[0010] Method for solving the problem

[0011] As a result of intensive studies by the present inventors, it has been found that an organosilicon viscoelastic material having excellent ductility can be obtained by reacting a linear polysiloxane having predetermined functional groups at both ends of the molecular chain with a cyclic siloxane having a functional group capable of undergoing an addition reaction with the above functional groups bonded to a silicon atom. Based on this finding, the present invention has been completed.

[0012] To solve the above problems, the silicone resin composition of the present invention comprises a cyclic siloxane (A) having a first functional group, a linear polysiloxane (B) having a second functional group capable of undergoing an addition reaction with the first functional group at both ends of the molecular chain, a linear polymer (C) having the first functional group at both ends of the molecular chain, and a photopolymerization initiator or a thermosetting catalyst (D) that initiates or promotes the addition reaction between the first functional group and the second functional group. The cyclic siloxane (A) is a cyclic siloxane represented by the following general formula (1), general formula (2), or general formula (3).

[0013] In general formula (1), general formula (2), and general formula (3), R a or the R a bonded to the silicon atom of the siloxane chain to form SiR a represents the first functional group. R b each independently represents an alkyl group or a phenyl group. m represents an integer of 3 to 5. In general formula (2) and general formula (3), n represents an integer of 1 to 1000. In general formula (3), Y represents an alkylene group.

[0014] The ratio of the number of the second functional groups of the linear polysiloxane (B) to the total number of the first functional groups of the cyclic siloxane (A) and the linear polymer (C) is 0.4 to 1.9. The molar ratio of the linear polymer (C) to the linear polysiloxane (B) is 0.4 or more and less than 0.6.

[0015]

[0016] The silicone resin composition of the present invention contains a cyclic siloxane (A) having a first functional group, a linear polysiloxane (B) having second functional groups capable of undergoing an addition reaction with the first functional group at both ends of the molecular chain, and a linear polymer (C) having the first functional group at both ends of the molecular chain. The molar ratio of the linear polymer (C) to the linear polysiloxane (B) is set to be 0.4 or more and less than 0.6, so that the linear polysiloxane (B) can be respectively bonded to both ends of the linear polymer (C) to extend the molecular chain of the polysiloxane. In addition, by setting the ratio of the number of second functional groups of the linear polysiloxane (B) to the total number of first functional groups of the cyclic siloxane (A) and the linear polymer (C) to be 0.4 to 1.9, the first functional group of the cyclic siloxane (A) can be subjected to an addition reaction with the second functional group on one end side of the molecular chain containing the linear polysiloxane (B) and the linear polymer (C) to be bonded, and at the same time, the second functional group on the other end side of the molecular chain containing the linear polysiloxane (B) and the linear polymer (C) can be subjected to an addition reaction with the first functional group of another cyclic siloxane (A) to be bonded. Thus, according to the present invention, it can be configured that: through an addition reaction, a linear copolymer molecular chain formed by bonding both ends of the linear polysiloxane (B) and the linear polymer (C) is connected between the cyclic siloxane (A) molecules. And by selecting a cyclic siloxane in which m in the general formula (1), general formula (2) or general formula (3) represents an integer of 3 to 5 as the cyclic siloxane (A), the cyclic siloxane (A) has the same number of first functional groups as m in its molecule. As a result, the cyclic siloxane (A) has as many branch points as the number of its first functional groups, which can be bonded to the linear polysiloxane molecule having a second functional group at the end through an addition reaction. Thus, at these 3 to 5 branch points, the cyclic siloxane and the molecular chain of the copolymer containing the polysiloxane molecule linearly extended in chain length can be crosslinked to obtain a silicone resin composition having excellent ductility of the cured product characteristics.

[0017] In addition, the silicone resin composition of the present invention contains a cyclic siloxane (A) having a first functional group, a linear polysiloxane (B) having second functional groups capable of undergoing an addition reaction with the first functional group at both ends of the molecular chain, and a photoinitiator or a thermal curing catalyst (D) that initiates or promotes the addition reaction between the first functional group and the second functional group. The cyclic siloxane (A) is a cyclic siloxane represented by the following general formula (1), general formula (2) or general formula (3).

[0018] In general formula (1), general formula (2) and general formula (3), R a or this R a SiR formed by bonding to the silicon atom of the siloxane chain arepresents a first functional group, R b Each independently represents an alkyl group or a phenyl group, m represents an integer of 3 to 5. In the general formula (2) and the general formula (3), n represents an integer of 1 to 1000. In the general formula (3), Y represents an alkylene group,

[0019] The ratio of the number of second functional groups of the linear polysiloxane (B) to the number of first functional groups of the cyclic siloxane (A) is 0.4 to 2.0.

[0020]

[0021] The organosilicon resin composition of the present invention comprises a cyclic siloxane (A) having a first functional group and a linear polysiloxane (B) having second functional groups capable of undergoing an addition reaction with the first functional group at both ends of the molecular chain. By setting the ratio of the number of second functional groups of the linear polysiloxane (B) to the number of first functional groups of the cyclic siloxane (A) to 0.4 to 2.0, the first functional group of the cyclic siloxane (A) can undergo an addition reaction with the second functional group on one end side of the molecular chain of the linear polysiloxane (B) to form a bond, and at the same time, the second functional group on the other end side of the molecular chain of the linear polysiloxane (B) can undergo an addition reaction with the first functional group of another cyclic siloxane (A) to form a bond. Thus, according to the present invention, it can be configured that during the addition reaction, a structure in which the linear polysiloxane (B) is connected between the cyclic siloxane (A) molecules can be formed. And by selecting a cyclic siloxane in which m in the general formula (1), the general formula (2) or the general formula (3) represents an integer of 3 to 5 as the cyclic siloxane (A), the cyclic siloxane (A) has the same number of first functional groups as m in its molecule. As a result, the cyclic siloxane (A) has as many branching points as the number of its first functional groups, which can be combined with the linear polysiloxane (B) having second functional groups at the ends through an addition reaction. Thus, at these 3 to 5 branching points, the cyclic siloxane (A) and the linear polysiloxane (B) can crosslink, and an organosilicon resin composition having excellent ductility of the cured product characteristics can be obtained.

[0022] In addition, in the silicone resin composition of the present invention, it is also preferable that one of the first functional group and the second functional group is an alkenyl group, and the other of the first functional group and the second functional group is a mercaptoalkyl group or a hydrosilyl group. Thus, suitable functional groups can be selected as the functional groups possessed by the constituent components of the silicone resin composition of the present invention, namely, the cyclic siloxane (A), the linear polysiloxane (B), and the linear polymer (C), or the functional groups possessed by the cyclic siloxane (A) and the linear polysiloxane (B). Here, the mercaptoalkyl group is a functional group in which one of the hydrogen atoms constituting the alkyl group is substituted with a mercapto group represented by the general formula SH, and this mercapto group can undergo an addition reaction with the double bond of the alkenyl group to form a C-S-C bond. In addition, the hydrosilyl group is represented by the general formula SiH and is formed by the bonding of a silicon atom and a hydrogen atom, and can undergo an addition reaction with the double bond of the alkenyl group to form a Si-C bond. Through such reactions, the constituent components of the silicone resin composition undergo addition polymerization with each other, thereby obtaining a gel-like or rubber-like cured product with excellent ductility.

[0023] In addition, it is also preferable that the cyclic siloxane (A) of the silicone resin composition of the present invention is a cyclic trisiloxane in which m represents an integer of 3 in the general formula (1), the general formula (2), or the general formula (3). Thus, a particularly preferred material can be selected as the constituent component of the silicone resin composition of the present invention, namely, the cyclic siloxane (A). By using the cyclic trisiloxane, a gel-like or rubber-like cured product with particularly excellent ductility can be obtained.

[0024] In addition, in the silicone resin composition of the present invention, it is also preferable that the first functional group is an alkenyl group and the second functional group is a mercaptoalkyl group or a hydrosilyl group. Further, the alkenyl group of the first functional group is also preferably a vinyl group. Thus, a more preferred functional group can be selected as the functional group possessed by the constituent components of the silicone resin composition of the present invention, namely, the cyclic siloxane (A), the linear polysiloxane (B), and the linear polymer (C), or the functional group possessed by the cyclic siloxane (A) and the linear polysiloxane (B). That is, the first functional group possessed by the cyclic siloxane (A) is preferably an alkenyl group, and particularly preferably a vinyl group. In addition, the second functional group possessed by the linear polysiloxane (B) is preferably a mercaptoalkyl group or a hydrosilyl group.

[0025] In addition, the silicone resin composition of the present invention also preferably further contains at least one functional filler (E) selected from the group consisting of a thixotropic filler, a thermally conductive filler, an electrically conductive filler, a magnetic filler, and a dielectric filler. Thus, desired properties can be imparted to the silicone resin composition and its cured product.

[0026] In addition, in the silicone resin composition of the present invention, it is also preferable that the linear polymer (C) is an organopolysiloxane represented by the following general formula (4). Here, in the general formula (4), R a or this Ra SiR bonded to the silicon atom at the end of the siloxane chain a represents a first functional group, R c each independently represents an alkyl group or a phenyl group, and p represents an integer of 25 to 2000. By selecting such a linear polymer (C), an addition reaction can be carried out with the linear polysiloxane (B) to extend the chain length of the polysiloxane molecule. Thus, a silicone resin composition capable of forming a stable cured product as an organosilicon viscoelastic material such as a silicone gel can be obtained.

[0027]

[0028] The cured product of the present invention is obtained by curing the above silicone resin composition. Since the cured product of the present invention has the above constitution, it has excellent ductility and high deformation followability.

[0029] In addition, the cured product of the present invention preferably has a breaking elongation rate (Eb) of 200% or more (in accordance with JIS K6251:2071) and a complex elastic modulus of 1000 to 150000 (in accordance with JIS K7244-10). Thus, a cured product having particularly suitable physical properties can be obtained.

[0030] The damping member of the present invention is composed of the above cured product. In addition, the electronic device of the present invention includes this damping member. The cured product (silicone gel or silicone rubber) having the above constitution is suitable for use as a damping member. For example, it can be provided as a damping member in a precision electronic device such as a camera module.

[0031] The heat sink of the present invention is composed of the above cured product. In addition, the electronic device of the present invention includes this heat sink. The cured product (silicone gel or silicone rubber) having the above constitution is suitable for use as a heat sink. For example, it can be provided as a heat sink in an electronic device such as a semiconductor etching apparatus.

[0032] Advantages of the Invention

[0033] According to the present invention, a silicone resin composition capable of forming a gel-like or rubber-like cured product (silicone gel or silicone rubber) having excellent ductility can be provided. Thus, a high breaking elongation rate (Eb) of the cured product can be achieved, and therefore, a damping member and a heat sink that are not easily damaged even when a tensile force is applied to the cured product and have excellent deformation followability can be provided. Detailed Description of the Invention

[0034] Hereinafter, the silicone resin composition of the present invention, its cured product, etc. will be described in detail.

[0035] (Silicone Resin Composition)

[0036] First, the silicone resin composition of the first embodiment of the present invention will be described. The silicone resin composition of the first embodiment includes: a cyclic siloxane (A) having a first functional group; a linear polysiloxane (B) having second functional groups capable of undergoing an addition reaction with the first functional group at both ends of the molecular chain; a linear polymer (C) having first functional groups at both ends of the molecular chain; and a photopolymerization initiator or a thermal curing catalyst (D) that initiates or promotes the addition reaction between the first functional group and the second functional group.

[0037] (Cyclic siloxane (A))

[0038] The cyclic siloxane (A) contained in the silicone resin composition of the present embodiment is a component capable of undergoing an addition reaction with the linear polysiloxane (B) described later, and is a cyclic siloxane (A1) represented by the following general formula (1), a cyclic siloxane (A2) represented by the following general formula (2), or a cyclic siloxane (A3) represented by the following general formula (3). In the general formula (1), general formula (2), and general formula (3), R a Or this R a Combined with the silicon atom of the siloxane chain to form SiR a Represents the first functional group, and R b Each independently represents an alkyl group or a phenyl group, m represents an integer of 3 to 5. In the general formula (2) and general formula (3), n represents an integer of 1 to 1000. In the general formula (3), Y represents an alkylene group.

[0039]

[0040] The cyclic siloxane (A1) represented by the general formula (1) is a cyclic siloxane in which m in the general formula (1) represents an integer of 3 to 5. More specifically, it is cyclic trisiloxane (m = 3), cyclic tetrasiloxane (m = 4), and cyclic pentasiloxane (m = 5). Among them, from the viewpoint of excellent ductility of the cured product, cyclic trisiloxane (m = 3) or cyclic tetrasiloxane (m = 4) is preferred, and cyclic trisiloxane (m = 3) is more preferred. It should be noted that the cyclic siloxane (A1) may also be a mixture of cyclic trisiloxane, cyclic tetrasiloxane, and cyclic pentasiloxane. The cyclic siloxane (A1) represented by the general formula (1) has R a Or this R a Combined with the silicon atom Si of the siloxane chain to form SiR a As the first functional group capable of undergoing an addition reaction with the second functional group of the linear polysiloxane (B) described later. R aEach is bonded to a silicon atom forming a siloxane ring. Therefore, the cyclic siloxane (A1) has, in the molecule, the same number of first functional groups as the number of silicon atoms forming the siloxane ring, that is, the number of m in the general formula (1). As the first functional group, any functional group that can undergo an addition reaction with the second functional group of the linear polysiloxane (B) may be used, and there is no particular limitation. For example, when R a in the general formula (1) is set as the first functional group, R a is preferably an alkenyl group or a mercaptoalkyl group. Here, as the alkenyl group, for example, in addition to vinyl, allyl, propenyl, isopropenyl, 2-methyl-1-propenyl, 2-methylallyl, 2-butenyl, etc., alkenylalkyl groups can also be cited, and vinyl is particularly preferred. In addition, as the mercaptoalkyl group, for example, mercaptoethyl, mercaptopropyl, mercaptobutyl, etc. can be cited. However, in the present invention, the mercapto group (general formula -SH) constituting the mercaptoalkyl group is preferably bonded to the end of the alkyl group, and 2-mercaptopropyl is particularly preferred. On the other hand, when R a bonded to the silicon atom Si of the siloxane chain to form SiR a is set as the first functional group, R a is preferably a hydrogen atom. Therefore, the first functional group is preferably a silicon hydride group (SiH). In the present embodiment, as the first functional group, from the viewpoint of ease of synthesis or acquisition of the material, an alkenyl group such as vinyl is preferably set as the first functional group R a . Further, if an alkenyl group is selected as the first functional group R a , then as the second functional group of the linear polysiloxane (B) described later, either a functional group that crosslinks by a photoreaction or a functional group that crosslinks by a thermal reaction can be selected, so it is easy to design a composition that satisfies the desired reaction system. On the other hand, if a mercaptoalkyl group is selected as the first functional group R a , the obtained organosilicon resin composition becomes a photocrosslinkable composition that undergoes an addition reaction by light energy. If a silicon hydride group is selected as the first functional group SiR a , the obtained organosilicon resin composition becomes a thermally crosslinkable composition that undergoes an addition reaction by heat energy.

[0041] As the cyclic siloxane (A1) that can be suitably used as the cyclic siloxane (A1) represented by the general formula (1) and having an alkenyl group as the first functional group R a , 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (both are products of Tokyo Chemical Industry Co., Ltd.), etc. can be cited.

[0042] In addition, as the first functional group R aThe cyclic siloxane (A1) having a mercaptoalkyl group, for example, can be synthesized through a synthesis route represented by the following formula. As an example, a cyclic vinylsiloxane that is a known compound: 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane, thioacetic acid, and 2,2′-azobis(2,4-dimethylvaleronitrile) (ADVN) are added to toluene and heated at 70 °C under a nitrogen atmosphere to obtain the following intermediate compound. After removing the solvent and the like by distillation under reduced pressure, it is dissolved in dehydrated THF under a nitrogen atmosphere, cooled using a dry ice-acetone bath, then a toluene solution of sodium bis(2-methoxyethoxy)aluminum hydride is added dropwise and allowed to react at room temperature, cooled to 0 °C, sodium sulfate, IPA, and water are added to stop the reaction, then acetic acid is added to make it weakly acidic, and solvent extraction is performed using cyclopentyl methyl ether, thereby obtaining the compound (m = 3) represented by the following formula. Similarly, by using 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane instead of 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane as the starting material, the first functional group R can be obtained. a The cyclic tetrasiloxane (m = 4) having a mercaptoalkyl group.

[0043]

[0044] In addition, as the first functional group SiR a The cyclic siloxane (A1) having a Si-H group can be produced, for example, by the method for producing a cyclic polysiloxane containing Si-H disclosed in Japanese Patent Laid-Open No. 2000-086766.

[0045] In addition, the cyclic siloxane (A2) represented by the general formula (2) is a cyclic siloxane in which m in the general formula (2) represents an integer of 3 to 5. More specifically, it is a cyclic trisiloxane (m = 3), a cyclic tetrasiloxane (m = 4), and a cyclic pentasiloxane (m = 5). Among them, from the viewpoint of excellent ductility of the cured product, a cyclic trisiloxane (m = 3) or a cyclic tetrasiloxane (m = 4) is preferred, and a cyclic trisiloxane (m = 3) is more preferred. It should be noted that the cyclic siloxane (A2) may also be a mixture of a cyclic trisiloxane, a cyclic tetrasiloxane, and a cyclic pentasiloxane. The cyclic siloxane (A2) represented by the general formula (2) has R a or the R a bonded to the silicon atom Si of the siloxane chain to form SiR a as the first functional group that can undergo an addition reaction with the second functional group of the linear polysiloxane (B) described later. The R aThe terminal of the siloxane chain after the silicon atom that combines to form a siloxane ring combines with other siloxane chains. Therefore, the cyclic siloxane (A2) has, in the molecule, the same number of first functional groups as the number of silicon atoms that form the siloxane ring, that is, the number of m in the general formula (2). As the first functional group, any functional group that can undergo an addition reaction with the second functional group of the linear polysiloxane (B) is acceptable, and there is no particular limitation. For example, when R a in the general formula (2) is set as the first functional group, R a is preferably an alkenyl or a mercaptoalkyl group. Here, as the alkenyl group, for example, in addition to vinyl, allyl, propenyl, isopropenyl, 2-methyl-1-propenyl, 2-methylallyl, and 2-butenyl, etc., alkenylalkyl groups can also be cited, and vinyl is particularly preferred. In addition, as the mercaptoalkyl group, for example, mercaptoethyl, mercaptopropyl, and mercaptobutyl can be cited, but in the present invention, the mercapto group (general formula -SH) constituting the mercaptoalkyl group is preferably bonded to the terminal of the alkyl group, and 2-mercaptopropyl is particularly preferred. On the other hand, when SiR a formed by bonding R a to the silicon atom Si at the terminal of the siloxane chain is set as the first functional group, R a is preferably set as a hydrogen atom, and therefore, the first functional group is preferably set as a silicon hydride group (SiH). In the present embodiment, from the viewpoint of the ease of synthesis or acquisition of the material, an alkenyl group such as vinyl is preferably set as the first functional group R a . Further, if an alkenyl group is selected as the first functional group R a , then as the second functional group of the linear polysiloxane (B) described later, either a functional group that crosslinks by a photoreaction or a functional group that crosslinks by a thermal reaction can be selected, and thus it is easy to design a composition that satisfies the desired reaction system. On the other hand, if a mercaptoalkyl group is selected as the first functional group R a , the obtained organosilicon resin composition becomes a photocrosslinkable composition that undergoes an addition reaction by light energy, and if a silicon hydride group is selected as the first functional group SiR a , the obtained organosilicon resin composition becomes a thermally crosslinkable composition that undergoes an addition reaction by heat energy. In addition, n in the general formula (2) represents an integer from 1 to 1000, preferably from 1 to 100, and more preferably from 1 to 10.

[0046] In the cyclic siloxane (A2) represented by the general formula (2), as the first functional group SiR aThe cyclic siloxane (A2) having a Si-H group can be produced, for example, by the method for producing a cyclic siloxane having a long-chain hydrocarbon group and a Si-H group disclosed in JP-A-2017-145231. Specifically, although not particularly limited, n-octyltrichlorosilane can be added to a mixed solution of water and THF, stirred at room temperature, and then 1,1,3,3-tetramethyldisilazane and dimethylchlorosilane are added and reacted at room temperature to obtain a first functional group SiR a is a cyclic trisiloxane (m = 3, n = 1) having a Si-H group.

[0047] In addition, as the first functional group R a The cyclic siloxane (A2) having an alkenyl group can be obtained by using, in the method for producing a cyclic siloxane disclosed in the above-mentioned JP-A-2017-145231, a compound in which the hydrogen atom bonded to the silicon atom in disilazane or monohalosilane is replaced by an alkenyl group such as vinyl in place of disilazane or monohalosilane, and reacting them to obtain a first functional group R a is a cyclic siloxane (A2) having an alkenyl group. Similarly, for the first functional group R a Regarding the cyclic siloxane (A2) having a mercaptoalkyl group, in the method for producing a cyclic siloxane disclosed in the above-mentioned JP-A-2017-145231, a compound in which the hydrogen atom bonded to the silicon atom in disilazane or monohalosilane is replaced by a mercaptoalkyl group can be used in place of disilazane or monohalosilane, and reacting them to obtain a first functional group R a is a cyclic siloxane (A2) having a mercaptoalkyl group.

[0048] In addition, the cyclic siloxane (A3) represented by the general formula (3) is a cyclic siloxane in which m in the general formula (3) represents an integer of 3 to 5. More specifically, it is a cyclic trisiloxane (m = 3), a cyclic tetrasiloxane (m = 4), and a cyclic pentasiloxane (m = 5). Among them, from the viewpoint of excellent ductility of the cured product, a cyclic trisiloxane (m = 3) or a cyclic tetrasiloxane (m = 4) is preferred, and a cyclic trisiloxane (m = 3) is more preferred. It should be noted that the cyclic siloxane (A3) may also be a mixture of a cyclic trisiloxane, a cyclic tetrasiloxane, and a cyclic pentasiloxane. The cyclic siloxane (A3) represented by the general formula (3) has R a or the R a is bonded to the silicon atom Si of the siloxane chain to form SiR a as a first functional group that can undergo an addition reaction with the second functional group of the linear polysiloxane (B) described later. The R aThe terminal of the silicone chain after the silicon atom incorporated to form a siloxane ring is bonded to other silicone chains via the alkylene group bonded thereto. Thus, the cyclic siloxane (A3) has, in the molecule, the same number of first functional groups as the number of silicon atoms forming the siloxane ring, i.e., the number of m in the general formula (3). As the first functional group, any functional group that can undergo an addition reaction with the second functional group of the linear polysiloxane (B) is acceptable and is not particularly limited. For example, when R a in the general formula (3) is set as the first functional group, R a is preferably an alkenyl group or a mercaptoalkyl group. Here, as the alkenyl group, for example, in addition to vinyl, allyl, propenyl, isopropenyl, 2-methyl-1-propenyl, 2-methylallyl, 2-butenyl, etc., alkenylalkyl groups can also be cited, and vinyl is particularly preferred. In addition, as the mercaptoalkyl group, for example, mercaptoethyl, mercaptopropyl, mercaptobutyl, etc. can be cited. However, in the present invention, the mercapto group (general formula -SH) constituting the mercaptoalkyl group is preferably bonded to the terminal of the alkyl group, and 2-mercaptopropyl is particularly preferred. On the other hand, when SiR a formed by bonding R a to the silicon atom Si at the terminal of the silicone chain is set as the first functional group, R a is preferably set as a hydrogen atom. Therefore, the first functional group is preferably a silicon hydride group (SiH). In the present embodiment, from the viewpoint of the ease of synthesis or acquisition of the material, an alkenyl group such as vinyl is preferably set as the first functional group R a . Further, if an alkenyl group is selected as the first functional group R a , then as the second functional group of the linear polysiloxane (B) described later, either a functional group crosslinked by a photoreaction or a functional group crosslinked by a thermal reaction can be selected. Therefore, it is easy to design a composition that satisfies the desired reaction system. On the other hand, if a mercaptoalkyl group is selected as the first functional group R a , the obtained organosilicon resin composition becomes a photocrosslinkable composition that undergoes an addition reaction by light energy. If a silicon hydride group is selected as the first functional group SiR a , the obtained organosilicon resin composition becomes a thermally crosslinkable composition that undergoes an addition reaction by thermal energy. In addition, n in the general formula (3) represents an integer of 1 to 1000, preferably 1 to 100, more preferably 1 to 10. Further, Y in the general formula (3) represents an alkylene group, preferably an alkylene group having 1 to 5 carbon atoms. For example, methylene, dimethylene, trimethylene, etc. can be cited.

[0049] In addition, in the cyclic siloxane (A1) represented by the general formula (1), the cyclic siloxane (A2) represented by the general formula (2), and the cyclic siloxane (A3) represented by the general formula (3), R of the side chain bonded to the silicon atom of the siloxane chain b represents an alkyl group or a phenyl group. R b can be independently set as an alkyl group or a phenyl group for each silicon atom forming the siloxane ring or each silicon atom forming the siloxane chain, and can be different. As the alkyl group represented by R b , for example, methyl, ethyl, propyl, isopropyl, etc. can be cited, and methyl is preferred. The alkyl group or phenyl group can be selected according to the physical properties required for the organosilicon viscoelastic material which is the cured product of the organosilicon resin composition, etc. as R b . It should be noted that within the range not hindering the effects of the present invention, R b can also be set as a non-reactive group such as a polyether group, an aralkyl group, a fluorine group, a fluoroalkyl group, a higher fatty acid ester group, or a higher fatty acid amide group.

[0050] In the cyclic siloxane (A3) represented by the general formula (3), as the cyclic siloxane (A3) in which the first functional group R a is an alkenyl group, for example, it can be synthesized through the synthesis route shown by the following formula. As an example, the cyclic hydrogenated siloxane which is a known compound: 2,4,6,8-tetramethylcyclotetrasiloxane (n = 0) and 1,3-divinyltetramethyldisiloxane which is a linear two-terminal vinyl siloxane (n = 2) are mixed at a mass ratio of cyclic hydrogenated siloxane / linear two-terminal vinyl siloxane = 1 / 15, and further, a Karstedt catalyst is added to toluene, and the reaction is carried out at 50 °C under a nitrogen atmosphere, thereby obtaining the compound shown by the following formula (m = 4, n = 1). Similarly, by using 2,4,6,8,10-pentamethylcyclotetrasiloxane (n = 0) as the cyclic hydrogenated siloxane in the starting material, a cyclic pentasiloxane (m = 5, n = 1) in which the first functional group R a is a vinyl group can be obtained.

[0051]

[0052] In addition, in the cyclic siloxane (A3) represented by the general formula (3), as the first functional group SiR aThe cyclic siloxane (A3) with a silane hydrogen group can be synthesized, for example, through the synthesis route shown by the following formula. As an example, a cyclic vinyl siloxane as a known compound: 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane (n = 0) and 1,1,3,3-tetramethyldisiloxane as a linear di-terminal hydrogenated siloxane (n = 2) are mixed at a mass ratio of cyclic vinyl siloxane / linear di-terminal hydrogenated siloxane = 1 / 15. Further, a Karstedt catalyst is added to toluene, and the reaction is carried out at 50 °C under a nitrogen atmosphere, thereby obtaining a compound (m = 3, n = 1) shown by the following formula. Similarly, by using 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (n = 0) as the cyclic vinyl siloxane in the starting material, the first functional group SiR a The cyclic tetrasiloxane (m = 4, n = 1) with a silane hydrogen group; by using 2,4,6,8,10-pentamethyl-2,4,6,8,10-pentavinylcyclopentasiloxane (n = 0) as the cyclic vinyl siloxane in the starting material, the first functional group SiR a The cyclic pentasiloxane (m = 5, n = 1) with a silane hydrogen group.

[0053]

[0054] Furthermore, in the cyclic siloxane (A3) represented by the general formula (3), as the first functional group R a The cyclic siloxane (A3) with a mercaptoalkyl group can be synthesized, for example, through the synthesis route shown by the following formula. As an example, a linear di-terminal hydrogenated siloxane as a known compound: 1,1,3,3,5,5-hexamethyltrisiloxane (n = 3), 2-allyloxytetrahydropyran, and a Karstedt catalyst are added to toluene, and the reaction is carried out at 50 °C under a nitrogen atmosphere to obtain Intermediate 1. Then, a cyclic vinyl siloxane: 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane (n = 0) and a Karstedt catalyst are added to toluene, and the reaction is carried out at 50 °C under a nitrogen atmosphere to obtain Intermediate 2. Pyridinium p-toluenesulfonate and methanol are added thereto, and the reaction is carried out at room temperature to obtain Intermediate 3. Then, carbon tetrabromide and dichloromethane are added, and a solution in which triphenylphosphine is dissolved in dichloromethane is added dropwise under ice-cooling, and the reaction is carried out by stirring to prepare Intermediate 4. Then, THF is added and dropped into a DMF solution of sodium hydrosulfide hydrate, and acidified with acetic acid, thereby obtaining a compound (m = 3, n = 2) shown by the following formula. Similarly, by using 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (n = 0) as the cyclic vinyl siloxane, the first functional group R aA cyclic tetrasiloxane having a mercaptoalkyl group (m = 4, n = 2); by using 2,4,6,8,10 - pentamethyl - 2,4,6,8,10 - pentavinylcyclotetrasiloxane (n = 0) as the cyclic vinylsiloxane in the starting materials, the first functional group R can be obtained. a A cyclic pentasiloxane having a mercaptoalkyl group (m = 5, n = 2).

[0055]

[0056] In addition, among the cyclic siloxanes represented by the general formulas (1) to (3), when a cyclic tetrasiloxane in which m in the general formula represents 4 is selected, a mixture of a cyclic tetrasiloxane having 4 first functional groups represented by the general formulas (1), (2), or (3) and a cyclic tetrasiloxane having 2 first functional groups in the para position can also be used. In addition, in the cyclic siloxane represented by the general formula (2) and the cyclic siloxane represented by the general formula (3), if the length of the side chain from the R at the end of the molecular chain constituting the first functional group a to the silicon atom of the silicon - oxygen ring is the same or close, a mixture of the cyclic siloxane represented by the general formula (2) and the cyclic siloxane represented by the general formula (3) can also be used.

[0057] (Linear polysiloxane (B))

[0058] The linear polysiloxane (B) contained in the organosilicon resin composition of this embodiment has second functional groups capable of undergoing an addition reaction with the first functional group at both ends of its molecular chain and can undergo an addition reaction with the above - mentioned cyclic siloxane (A) and the linear polymer (C) described later. As a more specific example, the linear polysiloxane (B) can be set as the linear organopolysiloxane represented by the following general formula (5). In this general formula (5), R d or this R d combined with the silicon atom at the end of the silicon - oxygen chain to form SiR d represents the second functional group, R e each independently represents a non - reactive group such as an alkyl group or a phenyl group, and r represents an integer from 30 to 2000.

[0059]

[0060] The linear polysiloxane (B) represented by the general formula (5) has R d or this R d combined with the silicon atom at the end of the silicon - oxygen chain to form SiR d as the second functional group capable of undergoing an addition reaction with the first functional groups of the cyclic siloxane (A) and the linear polymer (C) described later. The R dEach is bonded to the silicon atoms forming the two terminals of the siloxane chain, and high reactivity with the first functional group is generated at the two terminal portions of the linear polysiloxane (B). Therefore, it is possible to play a role of a structure in which a linear copolymer molecular chain formed by bonding the linear polysiloxane (B) to the cyclic siloxane (A) and the linear polymer (C) and bonding the two terminals of the linear polysiloxane (B) and the linear polymer (C) is connected between the cyclic siloxane (A) molecules. The second functional group may be any functional group that can undergo an addition reaction with the first functional group of the cyclic siloxane (A) or the linear polymer (C), and is not particularly limited. For example, when R d in the general formula (5) is set as the second functional group, R d is preferably an alkenyl group or a mercaptoalkyl group. Here, as the alkenyl group, for example, in addition to vinyl, allyl, propenyl, isopropenyl, 2-methyl-1-propenyl, 2-methylallyl, 2-buteneyl, etc., alkenylalkyl groups, etc. can also be cited, and vinyl is particularly preferred. In addition, as the mercaptoalkyl group, for example, mercaptoethyl, mercaptopropyl, mercaptobutyl, etc. can be cited, but in the present invention, the mercapto group constituting the mercaptoalkyl group is preferably bonded to the terminal of the alkyl group, and 2-mercaptopropyl is particularly preferred. On the other hand, when SiR d formed by bonding R d to the silicon atom at the terminal of the siloxane chain is set as the second functional group, R d is preferably a hydrogen atom, and therefore, the second functional group is preferably a silicon hydride group (SiH). In the present embodiment, from the viewpoint of the ease of synthesis or acquisition of the material, the second functional group is preferably a mercaptoalkyl group or a silicon hydride group, and particularly preferably a mercaptoalkyl group. In addition, r representing the degree of polymerization in the general formula (5) represents an integer of 30 to 2000. By setting the numerical value of r in the general formula (5) in the range of 30 to 2000, a cured product having excellent ductility and high deformation followability can be obtained. In addition, from the viewpoint of improving the ductility of the obtained cured product and adjusting the complex elastic modulus of the cured product to a preferred range, the total value (p + r) of r in the general formula (5) of the linear polysiloxane (B) and p in the general formula (4) of the linear polymer (C) described later is preferably 30 to 6000, more preferably 50 to 3000.

[0061] In addition, in the linear polysiloxane (B) represented by the general formula (5), R e of the side chain bonded to the silicon atom of the siloxane chain is preferably a non-reactive group. Examples of the non-reactive group include an alkyl group, a phenyl group, a polyether group, an aralkyl group, a fluorine group, a fluoroalkyl group, a higher fatty acid ester group, or a higher fatty acid amide group, etc. Among them, depending on the physical properties required for the cured product of the organosilicon resin composition, etc., an alkyl group or a phenyl group is preferably selected. R emay be independently set to an alkyl group or a phenyl group, and may be different for each silicon atom forming the silicone chain. As R e The alkyl group represented, for example, may include a methyl group, an ethyl group, a propyl group, an isopropyl group, etc., and is preferably a methyl group. In addition, from the viewpoint of improving the cold resistance of the obtained cured product (silicone gel, silicone rubber), it is preferable to set a part of R e in the linear polysiloxane (B) to a phenyl group.

[0062] As an example, in the linear polysiloxane (B) of the present invention, as the linear polysiloxane (B) in which the second functional group R d is a mercaptoalkyl group, examples thereof may include reactive silicone oils having mercaptopropyl groups at both ends (product names: X-22-167C, X-22-167B, both products of Shin-Etsu Chemical Co., Ltd.). In addition, as the linear polysiloxane (B) in which the second functional group SiR d is a silane group, examples thereof may include polydimethylsiloxanes having silane groups at both ends (product names: DMS-H21, DMS-H31, both products of Gelest Inc.). In addition, as the linear polysiloxane (B) in which the second functional group R d is an alkenyl group, examples thereof may include polydimethylsiloxanes having vinyl groups at both ends (product name: DMS-V31, product of Gelest Inc.).

[0063] (linear polymer (C))

[0064] The linear polymer (C) contained in the silicone resin composition of the present embodiment is a component having a first functional group at both ends of its molecular chain and capable of undergoing an addition reaction with the above-mentioned linear polysiloxane (B). Here, the so-called first functional group refers to the same functional group as the first functional group possessed by the cyclic siloxane (A). As the linear polymer, any polymer having the above-mentioned first functional group bonded to both ends of its molecular chain may be used, and there is no particular limitation. Polymers such as polysiloxane, polyolefin, polyurethane, polyamide, polyester, polystyrene, etc., and combinations thereof may be used. Among them, from the viewpoint of improving the stability such as heat resistance, weather resistance, and chemical resistance of the obtained cured product (silicone gel, silicone rubber), the linear polymer (C) is preferably a polysiloxane, and as a more specific example, it is preferably an organopolysiloxane represented by the following general formula (4). It should be noted that in the general formula (4), R a or SiR formed by bonding this R a to the silicon atom at the end of the silicone chain a represents the first functional group, and R c each independently represents a non-reactive group such as an alkyl group or a phenyl group, and p represents an integer of 25 to 2000.

[0065]

[0066] In the linear polymer (C) represented by the general formula (4), as the first functional group capable of undergoing an addition reaction with the second functional group possessed by the linear polysiloxane (B), it has R a or this R a SiR formed by bonding to the silicon atom Si at the end of the siloxane chain a . In this linear organopolysiloxane (C), the Rs constituting the first functional group a are each bonded to the silicon atoms forming the two ends of the siloxane chain, and high reactivity with the second functional group is generated at the two end portions of the molecule. Therefore, it is possible to exhibit the effect of lengthening the molecular chain of the polysiloxane by bonding the linear polysiloxane (B) to the two ends of the linear polymer (C) respectively. The description of the first functional group possessed by the linear polymer (C) is omitted because it is the same as the constitution of the first functional group possessed by the cyclic siloxane (A). In addition, p representing the degree of polymerization in the general formula (4) represents an integer of 25 to 2000. By setting the numerical value of p in the general formula (4) within the range of 25 to 2000, a cured product having excellent ductility and high deformation followability can be obtained. In addition, from the viewpoint of improving the ductility of the obtained cured product and adjusting the complex elastic modulus to a preferred range, the total value (p + r) of p in the general formula (4) of the linear polymer (C) and r in the general formula (5) of the above linear polysiloxane (B) is preferably 30 to 6000, more preferably 50 to 3000.

[0067] In addition, in the linear polymer (C) represented by the general formula (4), the R in the side chain bonded to the silicon atom of the siloxane chain c is preferably a non-reactive group. Examples of the non-reactive group include an alkyl group, a phenyl group, a polyether group, an aralkyl group, a fluorine group, a fluoroalkyl group, a higher fatty acid ester group, a higher fatty acid amide group, etc. Among them, an alkyl group or a phenyl group is preferably selected according to the physical properties required for the cured product of the organosilicon resin composition, etc. The Rs c can be independently set to an alkyl group or a phenyl group, and can be different for each silicon atom forming the siloxane chain. As the alkyl group represented by R c , for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, etc. can be mentioned, and a methyl group is preferred. In addition, from the viewpoint of improving the cold resistance of the obtained cured product (silicone gel, silicone rubber), a part of the R c in the side chain bonded to the silicon atom of the siloxane chain is preferably a phenyl group.

[0068] As an example, in the linear polymer (C) of the present invention, as the first functional group R that can be suitably used aThe linear polymer (C) of an alkenyl group includes, for example, polydimethylsiloxane having vinyl groups at both ends (product names: DMS-V31, DMS-V22, DMS-V42, all products of Gelest; product name: Rh-Vi321, product of Construe chemical), etc.

[0069] The first functional group and the second functional group of the components of the silicone resin composition of the present embodiment are not particularly limited as long as they can undergo an addition reaction with each other. Preferably, one of the first functional group and the second functional group is an alkenyl group, and the other of the first functional group and the second functional group is a mercaptoalkyl group or a silanyl group. That is, when the first functional group of the cyclic siloxane (A) and the linear polymer (C) is an alkenyl group, the second functional group of the linear polysiloxane (B) is preferably a mercaptoalkyl group or a silanyl group. In addition, when the first functional group of the cyclic siloxane (A) and the linear polymer (C) is a mercaptoalkyl group or a silanyl group, the second functional group of the linear polysiloxane (B) is preferably an alkenyl group. Here, as the alkenyl group, for example, in addition to vinyl, allyl, propenyl, isopropenyl, 2-methyl-1-propenyl, 2-methylallyl, 2-buteneyl, etc., alkenylalkyl, etc. can also be mentioned, and vinyl is particularly preferred. In addition, as the mercaptoalkyl group, for example, mercaptoethyl, mercaptopropyl, mercaptobutyl, etc. can be mentioned. However, in the present invention, the mercapto group (general formula -SH) constituting the mercaptoalkyl group is preferably bonded to the end of the alkyl group, and 2-mercaptopropyl is particularly preferred. This mercapto group can undergo an addition reaction with the double bond of the alkenyl group to form a C-S-C bond. In addition, the silanyl group is represented by the general formula -SiH and is formed by the bonding of a silicon atom and a hydrogen atom, and can undergo an addition reaction with the double bond of the alkenyl group to form a Si-C bond. Through such a reaction, the components of the silicone resin composition undergo addition polymerization with each other, thereby obtaining a silicone viscoelastic material having excellent ductility.

[0070] In the silicone resin composition of the present embodiment, when the first functional group R of the cyclic siloxane (A) and the linear polymer (C) a is an alkenyl group such as vinyl, the second functional group R of the linear polysiloxane (B) dIn the case where it is a mercaptoalkyl group, the addition reaction between the first functional group and the second functional group can be induced by a photoenergy reaction. Therefore, the organosilicon resin composition preferably contains a photopolymerization initiator as the component (D) that initiates or promotes the addition reaction between the first functional group and the second functional group. If the alkenyl group of the cyclic siloxane (A) undergoes an addition reaction with the mercaptoalkyl group at the end of the linear polysiloxane (B), the cyclic siloxane (A) and the linear polysiloxane (B) can be connected. On the other hand, if the alkenyl groups at both ends of the linear polymer (C) respectively undergo an addition reaction with the mercaptoalkyl group of the linear polysiloxane (B), the linear polysiloxane (B) can be connected to both ends of the linear polymer (C) to form a linear polysiloxane copolymer with an increased molecular chain length. Through the sequential occurrence of these addition reactions, a polymer in which the cyclic siloxane (A) molecules and the linear polysiloxane copolymer molecules are crosslinked can be formed.

[0071] Similarly, in the organosilicon resin composition of the present embodiment, when the first functional group R of the cyclic siloxane (A) and the linear polymer (C) a is a mercaptoalkyl group and the second functional group R of the linear polysiloxane (B) d is an alkenyl group such as vinyl, the addition reaction between the first functional group and the second functional group can be induced by a photoenergy reaction. Therefore, the organosilicon resin composition preferably contains a photopolymerization initiator as the component (D) that initiates or promotes the addition reaction between the first functional group and the second functional group. If the mercaptoalkyl group of the cyclic siloxane (A) undergoes an addition reaction with the alkenyl group at the end of the linear polysiloxane (B), the cyclic siloxane (A) and the linear polysiloxane (B) can be connected. On the other hand, if the mercaptoalkyl groups at both ends of the linear polymer (C) respectively undergo an addition reaction with the alkenyl group of the linear polysiloxane (B), the linear polysiloxane (B) can be connected to both ends of the linear polymer (C) to form a linear polysiloxane copolymer with an increased molecular chain length. Through the sequential occurrence of these addition reactions, a polymer in which the cyclic siloxane (A) molecules and the linear polysiloxane copolymer molecules are crosslinked can be formed.

[0072] On the other hand, in the organosilicon resin composition of the present embodiment, when the first functional group R of the cyclic siloxane (A) and the linear polymer (C) a is an alkenyl group such as vinyl and the second functional group SiR of the linear polysiloxane (B) dWhen the first functional group is a silicon hydride group, the addition reaction between the first functional group and the second functional group can be induced by a thermal reaction. Therefore, the organosilicon resin composition preferably contains a thermal curing catalyst as the component (D) for initiating or promoting the addition reaction between the first functional group and the second functional group. If the alkenyl group of the cyclic siloxane (A) undergoes an addition reaction with the silicon hydride group at the end of the linear polysiloxane (B), the cyclic siloxane (A) and the linear polysiloxane (B) can be connected. On the other hand, if the alkenyl groups at both ends of the linear polymer (C) respectively undergo an addition reaction with the silicon hydride group of the linear polysiloxane (B), the linear polysiloxane (B) can be connected to both ends of the linear polymer (C) to form a linear polysiloxane copolymer with an increased molecular chain length. By the successive occurrence of these addition reactions, a polymer with molecular crosslinking between the cyclic siloxane (A) molecules and the linear polysiloxane copolymer can be formed.

[0073] Similarly, in the organosilicon resin composition of the present embodiment, when the first functional group SiR of the cyclic siloxane (A) and the linear polymer (C) a is a silicon hydride group and the second functional group R of the linear polysiloxane (B) d is an alkenyl group such as vinyl, the addition reaction between the first functional group and the second functional group can be induced by a thermal reaction. Therefore, the organosilicon resin composition preferably contains a thermal curing catalyst as the component (D) for initiating or promoting the addition reaction between the first functional group and the second functional group. If the silicon hydride group of the cyclic siloxane (A) undergoes an addition reaction with the alkenyl group at the end of the linear polysiloxane (B), the cyclic siloxane (A) and the linear polysiloxane (B) can be connected. On the other hand, if the silicon hydride groups at both ends of the linear polymer (C) respectively undergo an addition reaction with the alkenyl group of the linear polysiloxane (B), the linear polysiloxane (B) can be connected to both ends of the linear polymer (C) to form a linear polysiloxane copolymer with an increased molecular chain length. By the successive occurrence of these addition reactions, a polymer with molecular crosslinking between the cyclic siloxane (A) molecules and the linear polysiloxane copolymer can be formed.

[0074] In the silicone resin composition of the present embodiment, from the viewpoint of efficiently extending the molecular chain of the polysiloxane molecule by bonding the linear polysiloxane (B) to both ends of the linear polymer (C) to form a linear polysiloxane copolymer, the molar ratio of the amount of the linear polymer (C) to the amount of the linear polysiloxane (B), that is, [(amount of (C)) / (amount of (B))] is preferably 0.4 or more and less than 0.6, more preferably 0.42 to 0.58, and particularly preferably 0.45 to 0.55. In addition, the ratio of the number of second functional groups of the linear polysiloxane (B) to the total number of first functional groups of the cyclic siloxane (A) and the linear polymer (C), that is, [number of second functional groups / total number of first functional groups] can be appropriately set according to the total molecular chain length (total molecular weight) of the linear polysiloxane (B) and the linear polymer (C), and is preferably 0.4 to 1.9, more preferably 0.5 to 1.6, and particularly preferably 0.7 to 1.4. More specifically, when the total molecular chain length (total molecular weight) of the linear polysiloxane (B) and the linear polymer (C) is small, it is preferably designed on the smaller range side in the above range, and when the total molecular chain length (total molecular weight) is large, it is preferably designed on the larger range side in the above range. Further in detail, when the total molecular weight of the linear polysiloxane (B) and the linear polymer (C) is less than 20000, it is more preferably 0.5 to 1.2, and particularly preferably 0.7 or more and less than 1.0. In addition, when the total molecular weight of the linear polysiloxane (B) and the linear polymer (C) is 20000 or more, it is more preferably 0.7 to 1.6, and particularly preferably 0.8 to 1.4. Thereby, the first functional group of the cyclic siloxane (A) can be made to undergo an addition reaction and bond to the second functional group on one end side of the molecular chain of the linear polysiloxane copolymer containing the linear polysiloxane (B) and the linear polymer (C), and at the same time, the second functional group on the other end side of the molecular chain of the linear polysiloxane copolymer can be made to undergo an addition reaction and bond to the first functional group of another cyclic siloxane (A). Thus, according to the present invention, it can be configured that: through an addition reaction, a structure in which two cyclic siloxane (A) molecules are connected by the molecular chain of the linear polysiloxane copolymer containing the linear polysiloxane (B) and the linear polymer (C) can be formed. It should be noted that the molecular weight in the present invention refers to the weight average molecular weight Mw, which is a value measured by gel permeation chromatography (GPC) method.

[0075] (Photoinitiator / Thermal curing catalyst (D))

[0076] The photoinitiator (D1) is a component that is used when the combination of the first functional group in the cyclic siloxane (A) and the linear polymer (C) and the second functional group in the linear polysiloxane (B) is, for example, a combination of an alkenyl group and a mercaptoalkyl group, and can initiate the addition reaction of the mercapto group of the mercaptoalkyl group with the alkenyl group. As the photoinitiator (D1), a known initiator that acts on the thiol-ene reaction under ultraviolet irradiation can be used. Examples of the photoinitiator (D1) include: 1-hydroxy-cyclohexyl-phenyl-ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzil dimethyl ketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide; Omnirad184, 369, 651, 500, 907, 1173, TPO H (manufactured by BASF Corporation, etc.). The photoinitiator (D1) can be compounded alone or in combination of two or more materials. In addition, the compounding amount of the photoinitiator is preferably set to an amount that can effectively initiate the thiol-ene reaction by actinic energy rays, and is preferably 0.05 to 50 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the total amount of the cyclic siloxane (A), the linear polysiloxane (B), and the linear polymer (C).

[0077] In addition, the thermosetting catalyst (D2) is a component that is used when the combination of the first functional group in the cyclic siloxane (A) and the linear polymer (C) and the second functional group in the linear polysiloxane (B) is, for example, a combination of an alkenyl group and a hydrosilyl group, and can promote the reaction between the hydrosilyl group and the alkenyl group. As the thermosetting catalyst (D2), known catalysts used in hydrosilylation reactions can be used. Examples of the thermosetting catalyst (D2) include: platinum group metal elements such as platinum, rhodium, and palladium; chloroplatinic acid, alcohol-modified chloroplatinic acid, a complex of chloroplatinic acid and vinylsiloxane, a chloroplatinic acid-2-ethylhexanol solution, etc.; platinum group catalysts such as tetrakis(triphenylphosphine)palladium, a mixture of palladium black and triphenylphosphine, etc. The thermosetting catalyst (D2) can be compounded alone or in combination of two or more materials. In addition, the compounding amount of the thermosetting catalyst is only required to be an amount that can effectively promote the hydrosilylation reaction by heat. In terms of the mass of the metal atom contained in the thermosetting catalyst, relative to the total amount of the cyclic siloxane (A), the linear polysiloxane (B), and the linear polymer (C), the amount is preferably 0.1 to 500 ppm, more preferably 1.0 to 100 ppm.

[0078] (Functional filler (E))

[0079] The silicone resin composition of the first embodiment of the present invention may further contain at least one functional filler (E) selected from the group consisting of thixotropic fillers, thermally conductive fillers, electrically conductive fillers, magnetic fillers, and dielectric fillers. These functional fillers have the function of imparting desired properties to the silicone resin composition or its cured product. The functional filler is contained in the silicone resin composition in an appropriate proportion within the range that does not impair the effects of the present invention.

[0080] A thixotropic filler is a component that can impart thixotropy to the silicone resin composition, that is, a property of having a high viscosity in a low shear rate region and a reduced viscosity in a high shear rate region. As the thixotropic filler, a known one or a mixture of two or more can be used. As the thixotropic filler, for example, inorganic fine particles such as fine silica, calcium carbonate, heavy calcium carbonate, bentonite, and sepiolite; resin fine particles such as Teflon (registered trademark) and silicone; organic compounds such as long-chain fatty acid ester polymers, amide waxes, polyethylene oxide waxes, sulfate-based anionic surfactants, polycarboxylic acids, polycarboxylic acid amine salts, and polyethers can be preferably used. The shape of the fine particles can be appropriately spherical, rod-shaped, flaky, etc.

[0081] The heat-conductive filler is a component that imparts heat conductivity to the silicone resin composition or its cured product, and one known type or a mixture of two or more types can be used. As the heat-conductive filler, for example, silica (quartz), alumina (bauxite), aluminum hydroxide, magnesium oxide, zinc oxide, boron nitride, aluminum nitride, silicon nitride, mica, ferrite, graphite, carbon nanotubes, carbon microcoils, etc. can be cited.

[0082] The electrically conductive filler is a component that imparts electrical conductivity to the silicone resin composition or its cured product, and one known type or a mixture of two or more types can be used. As the electrically conductive filler, for example, metals, carbon-based materials such as graphite, carbon nanotubes, carbon microcoils, fullerenes, and metal oxides such as zinc oxide can be used.

[0083] The magnetic filler is a component that imparts magnetism to the silicone resin composition or its cured product, and one known type or a mixture of two or more types can be used. As the magnetic filler, for example, Fe alloy powders such as iron powder, Fe-Si alloy powder, Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Cr alloy powder, Fe-Cr-Si alloy powder, spinel-type ferrite powders such as Mg-Zn ferrite, Mn-Zn ferrite, Mn-Mg ferrite, Cu-Zn ferrite, Mg-Mn-Sr ferrite, Ni-Zn ferrite, and hexagonal ferrite powders such as Ba-Zn ferrite, Ba-Mg ferrite, Ba-Ni ferrite, Ba-Co ferrite, Ba-Ni-Co ferrite, etc. can be cited.

[0084] The dielectric filler is a component that imparts dielectric properties to the silicone resin composition or its cured product, and one known type or a mixture of two or more types can be used. As the dielectric filler, for example, high-dielectric ceramic powders such as barium titanate, lead zirconate titanate (PZT), lanthanum-doped lead zirconate titanate (PLZT), strontium titanate, lead titanate, bismuth titanate, barium bismuth titanate, and organic compounds having a thiocarbonyl group such as thiourea derivatives, thioamide derivatives, thione derivatives, dithiocarbamate derivatives, etc. can be cited.

[0085] (Physical properties of the silicone resin composition)

[0086] Among the physical properties of the silicone resin composition of the present embodiment, the viscosity of the composition can be appropriately set according to the use, but from the viewpoints of coatability and dischargeability using a dispenser, etc., the viscosity at 23 °C is preferably 50 to 100,000 cP, more preferably 70 to 9000 cP, and further preferably 100 to 7000 cP.

[0087] The silicone resin composition of the present embodiment can be obtained by mixing the above-mentioned cyclic siloxane (A), linear polysiloxane (B), linear polymer (C), component (D) that initiates or promotes the addition reaction, and functional filler (E) and various other components added as needed in a predetermined mixing ratio. The order of mixing the components (A) to (D) or the components (A) to (E) etc. is not particularly limited. The mixing device is not particularly limited, and as an example, a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, or a roll mill etc. can be used.

[0088] (Cured product of the silicone resin composition)

[0089] Next, the cured product of the silicone resin composition of the present embodiment will be described. The cured product of the present embodiment is a gel-like or rubber-like cured product (silicone rubber or silicone gel) formed by the addition reaction of the constituent components of the above-mentioned silicone resin composition. The cured product thus formed has excellent ductility, and from the viewpoint of achieving high deformation followability, the elongation at break (Eb) is preferably 200% or more (in accordance with JIS K6251: 2071), more preferably the elongation at break (Eb) is 1000% or more, and particularly preferably the elongation at break (Eb) is 1500% or more. These physical property values can be designed to desired values by respectively adjusting the structure, compounding amount of the cyclic siloxane (A) that acts as the branching point of the crosslinked structure of the cured product, and the molecular chain length of the linear polysiloxane copolymer, etc. Further, from the viewpoint of achieving high damping property for use as a damping material, the complex elastic modulus of the cured product of the present invention is preferably 1000 to 150000 (in accordance with JIS K7244-10), more preferably the complex elastic modulus is 1500 to 100000, and particularly preferably the complex elastic modulus is 2000 to 70000.

[0090] (Uses of the cured product)

[0091] The cured product of the present embodiment has excellent ductility and high deformation followability, and thus can be used as a damping material, potting, heat dissipation material, sealing material, coating material, anti-vibration material, shock-absorbing material, and optical adhesive (OCR, OCA). In addition, the complex elastic modulus of the cured product of the present embodiment is also excellent, showing high damping property, so the cured product can be suitably used for a damping member that absorbs vibration while supporting precision components such as a camera module. In addition, the cured product of the present embodiment has excellent ductility, so even when a heat-conducting filler is compounded in a high proportion in the silicone resin composition to form a heat sink, it can be suitably used as a durable heat sink that is not easily damaged due to the maintained ductility and absorbs vibration while dissipating heat generated by a semiconductor etching device etc.

[0092] Next, the silicone resin composition of the second embodiment of the present invention will be described. The silicone resin composition of the second embodiment includes: a cyclic siloxane (A) having a first functional group; a linear polysiloxane (B) having second functional groups capable of undergoing an addition reaction with the first functional group at both ends of the molecular chain; and a photopolymerization initiator or a thermal curing catalyst (D) that initiates or promotes the addition reaction between the first functional group and the second functional group. In this embodiment, the difference is that it does not contain the linear polymer (C) that was a constituent in the aforementioned first embodiment. Hereinafter, for the silicone resin composition of the second embodiment, the constitution different from that of the first embodiment will be mainly described.

[0093] (Linear polysiloxane (B))

[0094] The linear polysiloxane (B) is a component having second functional groups capable of undergoing an addition reaction with the first functional group at both ends of its molecular chain and capable of undergoing an addition reaction with the above cyclic siloxane (A). As a more specific example, the linear polysiloxane (B) can be set as a linear organopolysiloxane represented by the following general formula (5). In this general formula (5), R d Or this R d Combined with the silicon atom at the end of the siloxane chain to form SiR d Represents the second functional group, and R e Each independently represents a non-reactive group such as an alkyl group or a phenyl group, and r represents an integer from 30 to 6000.

[0095]

[0096] The linear polysiloxane (B) represented by the general formula (5) has R d Or this R d Combined with the silicon atom at the end of the siloxane chain to form SiR d As the second functional group capable of undergoing an addition reaction with the first functional group of the cyclic siloxane (A). The R d That constitutes this second functional group is each combined with the silicon atoms forming both ends of the siloxane chain, generating a high reactivity with the first functional group at both end portions of the linear polysiloxane (B). Therefore, the effect of extending the polysiloxane chain between two cyclic siloxane (A) molecules can be exerted by the combination of the linear polysiloxane (B) and the cyclic siloxane (A). The second functional group only needs to be a functional group capable of undergoing an addition reaction with the first functional group of the cyclic siloxane (A), and can be set as the same functional group as the second functional group of the linear polysiloxane (B) in the first embodiment. In addition, regarding the R e Of the side chain combined with the silicon atom of the siloxane chain, it can also be set as the R e Of the side chain of the linear polysiloxane (B) in the first embodiment.Regarding the same side chain, in the general formula (5), r represents an integer from 30 to 6000, and from the viewpoint of improving the ductility of the obtained cured product, it is preferably from 50 to 5000, more preferably from 100 to 4000. By setting the value of r in the general formula (5) within this range, excellent ductility can be obtained, and a silicone viscoelastic material with high deformation followability can be obtained.

[0097] As an example, in the linear polysiloxane (B) of the present invention, as the second functional group R having a mercaptoalkyl group that can be suitably used d for the linear polysiloxane (B), examples include reactive silicone oils having mercaptopropyl groups at both ends (product names: X-22-167C, X-22-167B, both products of Shin-Etsu Chemical Co., Ltd.). In addition, as the second functional group SiR having a silane group d for the linear polysiloxane (B), examples include polydimethylsiloxanes having silane groups at both ends (product names: DMS-H21, DMS-H31, both products of Gelest Inc.). In addition, as the second functional group R having an alkenyl group d for the linear polysiloxane (B), examples include polydimethylsiloxanes having vinyl groups at both ends (product name: DMS-V31, a product of Gelest Inc.).

[0098] The first functional group and the second functional group of the constituent components of the silicone resin composition of the present embodiment are not particularly limited as long as they can undergo an addition reaction with each other. It is preferred that one of the first functional group and the second functional group is an alkenyl group, and the other of the first functional group and the second functional group is a mercaptoalkyl group or a silane group. That is, when the first functional group of the cyclic siloxane (A) is an alkenyl group, the second functional group of the linear polysiloxane (B) is preferably a mercaptoalkyl group or a silane group. In addition, when the first functional group of the cyclic siloxane (A) is a mercaptoalkyl group or a silane group, the second functional group of the linear polysiloxane (B) is preferably an alkenyl group.

[0099] In the silicone resin composition of the present embodiment, when the first functional group R of the cyclic siloxane (A) a is an alkenyl group such as vinyl, and the second functional group R of the linear polysiloxane (B) dWhen it is a mercaptoalkyl group, the addition reaction of the first functional group and the second functional group can be induced by a photoenergy reaction. Therefore, the organosilicon resin composition preferably contains a photoinitiator as the component (D) for initiating or promoting the addition reaction of the first functional group and the second functional group. If the alkenyl group of the cyclic siloxane (A) undergoes an addition reaction with the mercaptoalkyl group at the terminal of the linear polysiloxane (B), the cyclic siloxane (A) and the linear polysiloxane (B) can be connected. By the successive occurrence of these addition reactions, a polymer in which the linear polysiloxane (B) is connected between the cyclic siloxane (A) molecules can be formed.

[0100] Similarly, in the organosilicon resin composition of the present embodiment, when the first functional group R of the cyclic siloxane (A) a is a mercaptoalkyl group and the second functional group R of the linear polysiloxane (B) d is an alkenyl group such as a vinyl group, the addition reaction of the first functional group and the second functional group can be induced by a photoenergy reaction. Therefore, the organosilicon resin composition preferably contains a photoinitiator as the component (D) for initiating or promoting the addition reaction of the first functional group and the second functional group. If the mercaptoalkyl group of the cyclic siloxane (A) undergoes an addition reaction with the alkenyl group at the terminal of the linear polysiloxane (B), the cyclic siloxane (A) and the linear polysiloxane (B) can be connected. By the successive occurrence of these addition reactions, a polymer in which the linear polysiloxane (B) is connected between the cyclic siloxane (A) molecules can be formed.

[0101] On the other hand, in the organosilicon resin composition of the present embodiment, when the first functional group R of the cyclic siloxane (A) a is an alkenyl group such as a vinyl group and the second functional group SiR of the linear polysiloxane (B) d is a silicon hydride group, the addition reaction of the first functional group and the second functional group can be induced by a thermal reaction. Therefore, the organosilicon resin composition preferably contains a thermal curing catalyst as the component (D) for initiating or promoting the addition reaction of the first functional group and the second functional group. If the alkenyl group of the cyclic siloxane (A) undergoes an addition reaction with the silicon hydride group at the terminal of the linear polysiloxane (B), the cyclic siloxane (A) and the linear polysiloxane (B) can be connected. By the successive occurrence of these addition reactions, a polymer in which the linear polysiloxane (B) is connected between the cyclic siloxane (A) molecules can be formed.

[0102] Similarly, in the organosilicon resin composition of the present embodiment, when the first functional group SiR of the cyclic siloxane (A) a is a silicon hydride group and the second functional group R of the linear polysiloxane (B) dIn the case of an alkenyl group such as vinyl, the addition reaction between the first functional group and the second functional group can be induced by a thermal reaction. Therefore, the organosilicon resin composition preferably contains a thermal curing catalyst as the component (D) for initiating or promoting the addition reaction between the first functional group and the second functional group. If the hydrosilyl group of the cyclic siloxane (A) undergoes an addition reaction with the alkenyl group at the end of the linear polysiloxane (B), the cyclic siloxane (A) and the linear polysiloxane (B) can be linked. By the successive occurrence of these addition reactions, a polymer in which the linear polysiloxane (B) is linked between the cyclic siloxane (A) molecules and the cyclic siloxane (A) molecules can be formed.

[0103] In the organosilicon resin composition of the present embodiment, the ratio of the number of second functional groups of the linear polysiloxane (B) to the number of first functional groups of the cyclic siloxane (A), that is, [the number of second functional groups / the number of first functional groups], can be appropriately set according to the molecular chain length (molecular weight) of the linear polysiloxane (B), and is preferably 0.4 to 2.0, more preferably 0.5 to 1.6, and particularly preferably 0.7 to 1.4. More specifically, when the molecular chain length (molecular weight) of the linear polysiloxane (B) is small, it is preferably designed on the smaller range side of the above range, and when the molecular chain length (molecular weight) is large, it is preferably designed on the larger range side of the above range. Further in detail, when the molecular weight of the linear polysiloxane (B) is less than 20,000, it is more preferably 0.5 to 1.2, and particularly preferably 0.7 or more and less than 1.0. In addition, when the total molecular weight of the linear polysiloxane (B) is 20,000 or more, it is more preferably 0.7 to 1.6, and particularly preferably 0.8 to 1.4. Thus, the first functional group of the cyclic siloxane (A) can be caused to undergo an addition reaction and bond with the second functional group on one end side of the linear polysiloxane (B), and at the same time, the second functional group on the other end side of the linear polysiloxane (B) can be caused to undergo an addition reaction and bond with the first functional group of another cyclic siloxane (A). In this way, according to the present invention, it can be configured that, through the addition reaction, a structure in which the linear polysiloxane (B) molecules are bonded between the cyclic siloxane (A) molecules and the molecular chain between the cyclic siloxane (A) molecules is extended can be formed.

[0104] Other descriptions of the constituent components of the organosilicon resin composition of the present embodiment, that is, the cyclic siloxane (A) and the linear polysiloxane (B) molecules, are the same as those of the organosilicon resin composition of the first embodiment above, and their effects are also the same. In addition, the descriptions of the constituent components of the organosilicon resin composition in the present embodiment, that is, the photoinitiator / thermal curing catalyst (D) and the functional filler (E), are the same as those of the organosilicon resin composition of the first embodiment above, and their effects are also the same.

[0105] The silicone resin composition of the present embodiment can be obtained by mixing the above-mentioned cyclic siloxane (A), linear polysiloxane (B), component (D) that initiates or promotes the addition reaction, and functional fillers (E), various other components, etc. as required, in a predetermined mixing ratio. The order of mixing the components (A), (B), and (D) or the components (A), (B), (D), and (E), etc. is not particularly limited. The mixing device is not particularly limited. As an example, a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, or a roll mill, etc. can be used.

[0106] The cured product of the present embodiment is a gel-like or rubber-like cured product (silicone rubber or silicone gel) formed by the addition reaction of the constituent components of the above-mentioned silicone resin composition. The cured product thus formed has excellent ductility. From the viewpoint of achieving high deformation followability, the elongation at break (Eb) is preferably 200% or more (in accordance with JIS K6251: 2071), more preferably the elongation at break (Eb) is 500% or more, and particularly preferably the elongation at break (Eb) is 1000% or more. These physical property values can be designed to desired values by respectively adjusting the structure, compounding amount of the cyclic siloxane (A) that acts as a branching point of the crosslinked structure, and the molecular chain length of the linear polysiloxane (B), etc. Further, from the viewpoint of achieving high damping property for use as a damping material, the complex elastic modulus of the cured product of the present invention is preferably 1000 - 150000 (in accordance with JIS K7244-10), more preferably the complex elastic modulus is 1500 - 100000, and particularly preferably the complex elastic modulus is 2000 - 70000. In addition, the silicone viscoelastic material of the present embodiment has excellent ductility and high deformation followability, and thus can be used as a damping material, potting material, heat dissipation material, sealing material, coating material, anti-vibration material, shock absorption material, and optical adhesive (OCR, OCA). Further, the complex elastic modulus of the cured product of the present embodiment is also excellent, showing high damping property, so the cured product can be suitably used for a damping member that absorbs vibration while supporting precision components such as a camera module. In addition, the cured product of the present embodiment has excellent ductility, so even if a heat conductive filler is compounded in a high proportion in the silicone resin composition to form a heat sink, it can be suitably used as a durable heat sink that is not easily damaged due to the maintained ductility and absorbs vibration while dissipating heat generated by a semiconductor etching device, etc.

[0107] [Examples]

[0108] Hereinafter, the present invention will be described in more detail using examples and comparative examples. It should be noted that the present invention is not limited by these examples. The elongation at break (Eb) and complex elastic modulus G of the cured product of the silicone resin composition in the following examples and comparative examples ＊The method for measuring and evaluating the physical properties is as follows.

[0109] [Measuring and evaluating method]

[0110] (1) Elongation at break (Eb)

[0111] Prepare a cured product of the silicone resin composition into a sheet with a thickness of 2 mm, and use a No. 6 dumbbell to perform stamping to make a measurement sample. For this measurement sample, use a tensile testing machine (AG-Xplus, manufactured by Shimadzu Corporation) to measure the elongation at break (elongation at tensile fracture) (Eb) at 23 °C under the condition of 500 mm / min according to JIS K6251:2017 as the elongation rate (%) at break.

[0112] (2) Evaluation of elongation at break

[0113] The composition of the comparative example is a composition having the same components other than the cyclic siloxane (A). For the composition containing the linear polymer (C) in the components, a composition is prepared in which the ratio of the total number of the second functional groups to the number of the first functional groups (second functional group / first functional group) and the ratio of the amount of substance of the linear polymer (C) to the amount of substance of the linear polysiloxane (B) [(amount of substance of (C) / amount of substance of (B))] are equal. For the composition not containing the linear polymer (C) in the components, a composition is prepared in which the ratio of the total number of the second functional groups to the number of the first functional groups (second functional group / first functional group) is equal. The elongation rate (%) at break of the measurement sample of the comparative example is compared with the elongation rate (%) at break of the measurement sample of the corresponding example. If the elongation rate of the measurement sample of the example shows a value higher than that of the comparative example, it is judged as qualified (○). If it shows the same value as or lower than the elongation rate of the comparative example, it is judged as unqualified (×). In addition, since the sheet-shaped cured product prepared as the comparative example corresponding to the example cannot maintain the shape of the measurement sample, various physical property measurements cannot be performed. In the case where the elongation rate (%) at break of the measurement sample of the comparative example cannot be obtained, the case where the elongation rate (%) at break of the measurement sample of the example is 200% or more is judged as qualified (○), and the case where it is less than 200% is judged as unqualified (×). It should be noted that the respective comparative examples corresponding to the respective examples described later are as follows. Comparative example 1 corresponds to examples 1 and 2, comparative example 2 corresponds to example 3, comparative example 3 corresponds to example 4, comparative example 7 corresponds to example 5, comparative example 4 (or comparative example 23) corresponds to example 6, comparative example 8 corresponds to example 7, comparative example 9 corresponds to example 8, comparative example 10 corresponds to example 9, comparative example 5 corresponds to example 10, comparative example 11 corresponds to example 11, and comparative example 6 corresponds to example 12. Similarly, comparative example 12 corresponds to example 13, comparative example 13 corresponds to example 14, comparative example 14 corresponds to example 15, comparative example 15 corresponds to example 16, comparative example 16 corresponds to example 17, comparative example 17 corresponds to example 18, and comparative example 18 corresponds to example 19. In addition, comparative example 24 corresponds to example 20, comparative example 25 (or comparative example 33) corresponds to example 21, comparative example 26 corresponds to example 22, comparative example 27 corresponds to example 23, comparative example 28 corresponds to example 24, comparative example 29 corresponds to example 25, and comparative example 30 corresponds to example 26.

[0114] (3) Complex elastic modulus G ＊

[0115] The cured product of the silicone resin composition was prepared into a sheet with a thickness of 2 mm, punched into a shape of φ25 mm or φ8 mm to make a measurement sample. Using a rheometer (ARES-G2, manufactured by TA Instruments), the dynamic viscoelasticity of each measurement sample was measured according to JIS K7244-10, and the complex elastic modulus G at 25 °C and 10 Hz was obtained. ＊ .

[0116] The specifications of the constituent components of the silicone resin compositions prepared in the following examples and comparative examples are shown in Tables 1 and 2. It should be noted that the molecular weights of the respective components shown in the tables and the degree of polymerization values represented by p or r are calculated values based on the design values described in the respective product specifications or molecular formulas.

[0117] [Table 1]

[0118]

[0119] [Table 2]

[0120]

[0121] In addition, among the compounds shown in Table 1 above, the compounds A2 and A3 as in-house synthesized products were synthesized as follows.

[0122] [Synthesis of Compound A2]

[0123] Compound A2 was manufactured based on the manufacturing method of cyclic siloxanes having a hydrocarbon group and a silicon hydride group disclosed in Japanese Patent Laid-Open No. 2017-145231. Methyltrichlorosilane (1.81 g, 12.1 mmol) was added dropwise to a mixed solution of water (0.65 g, 36.3 mmol) and THF (120 mL) at room temperature over 2 minutes, and the mixture was stirred at room temperature for 1 hour. Then, 1,1,3,3-tetramethyldisilazane (1.6 g, 12 mmol) and dimethylchlorosilane (0.23 g, 2.4 mmol) were added to the reaction solution and stirred at room temperature for 3 hours. Then, liquid separation operation using diethyl ether and water was performed to extract the target substance. Cyclic size exclusion chromatography using chloroform as the developing solvent was carried out to obtain 0.48 g of Compound A2 with a yield of 31%. This operation was repeated 7 times to obtain a total of 3.3 g of Compound A2.

[0124] 1 1H-NMR (CDCl3) δ: 0.12 - 0.22 (m, 27H), 3.55 - 3.63 (m, 3H)

[0125] [Synthesis of Compound A3]

[0126] Compound A3 was synthesized based on the following formula. 1,1,3,3,5,5-Hexamethyltrisiloxane (20.8 g, 100 mmol), which is a linear di-terminal hydrosiloxane (n = 3), 2-allyloxytetrahydropyran (7.1 g, 50 mmol), and Karstedt's catalyst (10 μL) were added to 200 mL of toluene, and heated at 50 °C for 2 hours under a nitrogen atmosphere. After distilling off the solvent, column purification was carried out to obtain Intermediate 1. Then, 2,4,6-Trimethyl-2,4,6-trivinylcyclotrisiloxane (1.8 g, 7 mmol), which is a cyclic vinylsiloxane (n = 0), and Karstedt's catalyst (10 μL) were added to 200 mL of toluene, and heated at 50 °C for 2 hours under a nitrogen atmosphere. After distilling off the solvent, column purification was carried out to obtain Intermediate 2. Then, pyridinium p-toluenesulfonate (100 mg) and 100 mL of methanol were added thereto, and stirred at room temperature for 2 hours. The solvent was distilled off, and column purification was carried out to obtain Intermediate 3. Then, carbon tetrabromide (10.5 g, 32 mmol) and 100 mL of dichloromethane were added, and a solution in which triphenylphosphine (9.9 g, 38 mmol) was dissolved in 50 mL of dichloromethane was added dropwise under ice-cooling and stirred for 1 hour. After distilling off the solvent, column purification was carried out to prepare Intermediate 4. Then, 50 mL of tetrahydrofuran was added, and it was added dropwise to a solution of sodium hydrosulfide hydrate (1.7 g, 21 mmol) in 50 mL of DMF. After acidifying with acetic acid, water was added, and liquid separation was carried out using hexane and ethyl acetate, followed by drying with anhydrous sodium sulfate. After distilling off the solvent, column purification was carried out to obtain 4.4 g of Compound A3 in a yield of 57%.

[0127] 1 H-NMR (CDCl3) δ: 0.12 - 0.22 (m, 63H), 0.55 - 0.65 (m, 18H), 1.53 (m, 6H), 2.43 (t, 6H)

[0128]

[0129] [Example 1]

[0130] The silicone resin composition and its cured product of this example were prepared in the following order, and various physical properties were measured by the above tests. The mixing ratios of the constituent components of the silicone resin composition in this example are shown in Table 3 below. The material numbers (No.) in Table 3 correspond to the material numbers shown in Tables 1 and 2. Using each constituent component shown in Tables 1 and 2, the cyclic siloxane (A) uses a cyclic trisiloxane (A1-1) having vinyl as the first functional group, the linear polysiloxane (B) uses a linear polysiloxane (B1) having mercaptopropyl at both ends as the second functional group and a molecular weight of 4600, the linear polymer (C) uses a polydimethylsiloxane (C1) having vinyl at both ends as the first functional group and a molecular weight of 28000, and the photoinitiator uses the product name of BASF: Omnirad1173 (D1). Weigh 0.186 g of component A1-1, 12.07 g of component B1, 36.74 g of component C1, and 1.00 g of component D1, and put them into a plastic container with a lid. Mix them in such a way that the total ratio of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group in the constituent components (second functional group / first functional group) becomes 1.1. In addition, mix them in such a way that the molar ratio of the linear polymer (C) to the linear polysiloxane (B) in the constituent components [(amount of substance of (C)) / (amount of substance of (B))] becomes 0.5. It should be noted that the ratio of the number of the second functional group / first functional group and the molar ratio of component (C) / component (B) shown in Table 3 are values calculated based on the molecular weight values of each material shown in Tables 1 and 2. After kneading the above mixture at 2000 rpm for 3 minutes using a planetary mixer (product name: THINKY MIXER (registered trademark) ARE-350, product of THINKY CORPORATION), perform centrifugal defoaming at 2200 rpm for 1 minute to obtain the silicone resin composition of Example 1. The obtained silicone resin composition was formed into a sheet on a transparent glass so that the thickness of the cured product became 2 mm, and ultraviolet rays with a wavelength of 365 nm were irradiated from each direction of the top and bottom surfaces at 3000 mJ / cm 2 to cure it, thereby obtaining a sheet-shaped cured product. For this cured product, the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement method.

[0131] [Example 2]

[0132] In this example, as the cyclic siloxane (A), the material A1-1 used in Example 1 was replaced with a cyclic tetrasiloxane (A1-2) having a vinyl group as the first functional group. Except for this, the operation was the same as in Example 1 to obtain the silicone resin composition of Example 2. The obtained silicone resin composition was molded into a sheet on a transparent glass so that the thickness of the cured product became 2 mm, and ultraviolet rays with a wavelength of 365 nm were irradiated from each direction of the top surface and the bottom surface at 3000 mJ / cm 2 to cure it, thereby obtaining a sheet-like cured product. For this cured product, the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement method.

[0133] [Comparative Example 1]

[0134] Comparative Example 1 is different from Examples 1 and 2. Instead of using the cyclic siloxane (A), a linear siloxane (a1) having a plurality of vinyl groups as the first functional group was used. In this linear siloxane, the number of Si having a vinyl group was 4.67 mol% on average with respect to the number of Si constituting 1 mol of the linear siloxane (model: RH-Vi315, product of Construe chemical company). The other constituent materials used the same materials as in Examples 1 and 2, and the blending amounts of the respective materials (a1, B1, C1, and D1) were changed to the blending amounts shown in Table 3. Except for this, the operation was the same as in Examples 1 and 2 to obtain the silicone resin composition of Comparative Example 1. It should be noted that the blending amounts of the respective constituent materials were adjusted so that the total ratio of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group (second functional group / first functional group) in each constituent material was 1.1 in the same manner as in Examples 1 and 2, and the molar ratio of the linear polymer (C) to the linear polysiloxane (B) [(amount of substance of (C) / (amount of substance of (B))] was also 0.5 in the same manner as in Examples 1 and 2. The obtained silicone resin composition was molded into a sheet on a transparent glass so that the thickness of the cured product became 2 mm, and ultraviolet rays with a wavelength of 365 nm were irradiated from each direction of the top surface and the bottom surface at 3000 mJ / cm 2 to cure it, thereby obtaining a sheet-like cured product. For this cured product, the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement method.

[0135] [Example 3]

[0136] In this example, the compounding amounts of the respective materials (A1-1, B1, C1, and D1) used in Example 1 were changed to the compounding amounts shown in Table 3. Other than that, the operation was the same as in Example 1 to obtain the silicone resin composition of Example 3. In addition, the total ratio of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group in the constituent components (second functional group / first functional group) was 1.2, and the molar ratio of the linear polymer (C) to the linear polysiloxane (B) [(molar amount of (C) / (molar amount of (B))] was 0.5. For the obtained silicone resin composition, a sheet-like cured product was prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement methods.

[0137] [Comparative Example 2]

[0138] In this comparative example, the compounding amounts of the respective materials (a1, B1, C1, and D1) used in Comparative Example 1 were changed to the compounding amounts shown in Table 3. Other than that, the operation was the same as in Comparative Example 1 to obtain the silicone resin composition of Comparative Example 2. It should be noted that the total ratio of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group in each constituent component (second functional group / first functional group) was made to be 1.2 in the same manner as in Example 3, and the molar ratio of the linear polymer (C) to the linear polysiloxane (B) [(molar amount of (C) / (molar amount of (B))] was also made to be 0.5 in the same manner as in Example 3 by adjusting the compounding amounts of the respective constituent components. For the obtained silicone resin composition, a sheet-like cured product was prepared in the same order as in Comparative Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement methods.

[0139] [Example 4]

[0140] In this example, the compounding amounts of the respective materials (A1-1, B1, C1, and D1) used in Example 1 were changed to the compounding amounts shown in Table 3. Other than that, the operation was the same as in Example 1 to obtain the silicone resin composition of Example 4. In addition, the total ratio of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group in the constituent components (second functional group / first functional group) was 1.4, and the molar ratio of the linear polymer (C) to the linear polysiloxane (B) [(molar amount of (C) / (molar amount of (B))] was 0.5. For the obtained silicone resin composition, a sheet-like cured product was prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊Determination and evaluation.

[0141] [Comparative Example 3]

[0142] In this comparative example, the compounding amounts of the respective materials (a1, B1, C1, and D1) used in Comparative Example 1 were changed to the compounding amounts shown in Table 3. Otherwise, the operation was the same as in Comparative Example 1 to obtain the silicone resin composition of Comparative Example 3. It should be noted that the total ratio of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group (second functional group / first functional group) in each constituent component was made 1.4 in the same manner as in Example 4, and the ratio of the amount of substance of the linear polymer (C) to the amount of substance of the linear polysiloxane (B) [(amount of substance of (C)) / (amount of substance of (B))] was also made 0.5 in the same manner as in Example 4 to adjust the compounding amounts of the respective constituent components. For the obtained silicone resin composition, a sheet-like cured product was prepared in the same order as in Comparative Example 1, and the elongation at break (Eb) and the complex elastic modulus G were measured and evaluated according to the above measurement method. ＊ Determination and evaluation.

[0143] [Examples 5 to 8]

[0144] In this example, among the respective constituent components, the polydimethylsiloxane (C1) of the linear polymer (C) material used in Example 1 was replaced with a polydimethylsiloxane (C2) having a shorter molecular chain length. In addition, the same materials as in Example 1 were used, and the compounding amounts of the respective materials (A1-1, B1, C2, and D1) were changed to the compounding amounts shown in Table 4. Otherwise, the operation was the same as in Example 1 to obtain the silicone resin compositions of Examples 5 to 8. It should be noted that the total ratio of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group (second functional group / first functional group) in each constituent component was 0.8 (Example 5), 0.9 (Example 6), 1.0 (Example 7), and 1.2 (Example 8), and the ratio of the amount of substance of the linear polymer (C) to the amount of substance of the linear polysiloxane (B) [(amount of substance of (C)) / (amount of substance of (B))] was 0.5. For each of the obtained silicone resin compositions, a sheet-like cured product was prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G were measured and evaluated according to the above measurement method. ＊ Determination and evaluation.

[0145] [Comparative Examples 4, 7 to 9]

[0146] In this comparative example, among the respective constituent components, the polydimethylsiloxane (C1) of the linear polymer (C) material used in Comparative Example 1 was replaced with a polydimethylsiloxane (C2) having a shorter molecular chain length. In addition, the same materials as those in Comparative Example 1 were used, and the compounding amounts of the respective materials (a1, B1, C2, and D1) were changed to the compounding amounts shown in Table 4. Other than this, the operation was the same as in Comparative Example 1, and silicone resin compositions of Comparative Examples 4 and 7 to 9 were obtained. It should be noted that the total ratio (second functional group / first functional group) of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group in each constituent component was made to be 0.8 (Comparative Example 7), 0.9 (Comparative Example 4), 1.0 (Comparative Example 8), and 1.2 (Comparative Example 9) in the same manner as in the corresponding Examples 5 to 8, and the ratio of the amount of substance of the linear polymer (C) to the amount of substance of the linear polysiloxane (B) [(amount of substance of (C)) / (amount of substance of (B))] was also made to be 0.5 in the same manner as in the corresponding Examples 5 to 8, and the compounding amounts of the respective constituent components were adjusted. For the obtained silicone resin compositions, sheet-like cured products were prepared in the same order as in Comparative Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement method.

[0147] [Examples 9 to 11]

[0148] In this example, among the respective constituent components, the polydimethylsiloxane (C1) of the linear polymer (C) material used in Example 1 was replaced with a polydimethylsiloxane (C3) having a longer molecular chain length. In addition, the same materials as those in Example 1 were used, and the compounding amounts of the respective materials (A1-1, B1, C3, and D1) were changed to the compounding amounts shown in Table 5. Other than this, the operation was the same as in Example 1, and silicone resin compositions of Examples 9 to 11 were obtained. It should be noted that the total ratio (second functional group / first functional group) of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group in each constituent component was 1.0 (Example 9), 1.2 (Example 10), and 1.4 (Example 11), and the ratio of the amount of substance of the linear polymer (C) to the amount of substance of the linear polysiloxane (B) [(amount of substance of (C)) / (amount of substance of (B))] was 0.5. For each of the obtained silicone resin compositions, sheet-like cured products were prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated.

[0149] [Comparative Examples 5 and 10 to 11]

[0150] In this comparative example, among the respective constituent components, the polydimethylsiloxane (C1) of the linear polymer (C) material used in Comparative Example 1 was replaced with polydimethylsiloxane (C3) having a longer molecular chain length. In addition, the same materials as those in Comparative Example 1 were used, and the compounding amounts of the respective materials (a1, B1, C3, and D1) were changed to the compounding amounts shown in Table 5. Other than this, the operation was the same as in Comparative Example 1, and silicone resin compositions of Comparative Examples 5 and 10 to 11 were obtained. It should be noted that the total ratio (second functional group / first functional group) of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group in each constituent component was made to be 1.0 (Comparative Example 10), 1.2 (Comparative Example 5), and 1.4 (Comparative Example 11) in the same manner as in Examples 9 to 11 corresponding thereto, and the compounding amounts of the respective constituent components were adjusted such that the molar ratio of the linear polymer (C) to the linear polysiloxane (B) [(amount of substance of (C)) / (amount of substance of (B))] also became 0.5 in the same manner as in Examples 9 to 11 corresponding thereto. For the obtained silicone resin composition, a sheet-like cured product was prepared in the same order as in Comparative Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above-mentioned measurement method.

[0151] [Example 12]

[0152] In this example, a composition was prepared without using the linear polymer (C) material used in Example 1 among the respective constituent components. In addition, the same materials as those in Example 1 were used, and the compounding amounts of the respective materials (A1-1, B1, and D1) were changed to the compounding amounts shown in Table 6. Other than this, the operation was the same as in Example 1, and a silicone resin composition of Example 12 was obtained. It should be noted that the ratio of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group (second functional group / first functional group) in each constituent component was 0.5. For the obtained silicone resin composition, a sheet-like cured product was prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above-mentioned measurement method.

[0153] [Comparative Example 6]

[0154] In this comparative example, a composition was prepared without using the linear polymer (C) material used in Comparative Example 1 among the respective constituent components. In addition, the same materials as those in Comparative Example 1 were used, and the compounding amounts of the respective materials (a1, B1, and D1) were changed to the compounding amounts shown in Table 6. Except for this, the operation was the same as that in Comparative Example 1, and a silicone resin composition of Comparative Example 6 was obtained. It should be noted that the compounding amounts of the respective constituent components were adjusted so that the ratio of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group (second functional group / first functional group) in each constituent component became 0.5 in the same manner as in Example 12. For the obtained silicone resin composition, a sheet-like cured product was prepared in the same order as in Comparative Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement methods.

[0155] [Examples 13 to 16]

[0156] In this example, among the respective constituent components, the polydimethylsiloxane (C1) of the linear polymer (C) material used in Example 1 was replaced with polydimethylsiloxanes (C2 to C4) having various chain lengths shown in Table 2. In addition, the same materials as those in Example 1 were used, and the compounding amounts were changed to the compounding amounts shown in Table 7. Except for this, the operation was the same as that in Example 1, and silicone resin compositions of Examples 13 to 16 were obtained. It should be noted that the total ratio of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group (second functional group / first functional group) in each constituent component and the ratio of the amount of substance of the linear polymer (C) to the amount of substance of the linear polysiloxane (B) [(amount of substance of (C)) / (amount of substance of (B))] are shown in Table 7, respectively. For each of the obtained silicone resin compositions, a sheet-like cured product was prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement methods.

[0157] [Comparative Examples 12 to 15]

[0158] In this comparative example, among the respective constituent components, the polydimethylsiloxane (C1) of the linear polymer (C) material used in Comparative Example 1 was replaced with polydimethylsiloxanes (C2 to C4) having various chain lengths shown in Table 2. In addition, the same materials as those in Comparative Example 1 were used, and the compounding amounts were changed to the compounding amounts shown in Table 7. Other than that, the operation was the same as in Comparative Example 1, and silicone resin compositions of Comparative Examples 12 to 15 were obtained. It should be noted that the total ratio (second functional group / first functional group) of the number of mercaptopropyl groups as the second functional group to the number of vinyl groups as the first functional group in each constituent component was made equal to that of the corresponding Examples 13 to 16, and the molar ratio of the linear polymer (C) to the linear polysiloxane (B) [(amount of substance of (C)) / (amount of substance of (B))] was also made equal to the corresponding values of Examples 13 to 16 to adjust the compounding amounts of the respective constituent components. For the obtained silicone resin compositions, sheet-like cured products were prepared in the same order as in Comparative Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement methods.

[0159] [Example 17]

[0160] In this example, among the respective constituent components, the polydimethylsiloxane (B1) having mercaptopropyl groups at both ends and the photoinitiator (D1) in the materials used in Example 5 were respectively replaced with polydimethylsiloxane (B3) having hydrosilyl groups at both ends and a thermal curing catalyst (D2) shown in Table 2. The silicone resin composition and its cured product of this example were prepared in the following order, and various physical properties were measured by the above tests. The mixing ratio of the constituent components of the silicone resin composition in this example is shown in Table 8 below. The material numbers in Table 8 correspond to the material numbers shown in Tables 1 and 2. With the ratio of the number of hydrosilyl groups as the second functional group to the number of vinyl groups as the first functional group (second functional group / first functional group) in each constituent component being 1.2 and the ratio of the amount of substance of the linear polymer (C) to the amount of substance of the linear polysiloxane (B) [(amount of substance of (C)) / (amount of substance of (B))] being 0.5, 0.186 g of Component A1-1, 14.583 g of Component B3, 15.231 g of Component C2, and 150 μL of Component D2 were mixed. Using a planetary mixer (product name: THINKY MIXER (registered trademark) ARE-350, manufactured by Shin Kiki Co., Ltd.), the above mixture was kneaded at 2000 rpm for 3 minutes and then defoamed by centrifugation at 2200 rpm for 1 minute, thereby obtaining the silicone resin composition of Example 17. After the uncured silicone resin composition was roll-molded into a sheet with a thickness of 2 mm, it was preheated in a hot air oven (WFO-520W manufactured by Tokyo Rika Kikai Co., Ltd.) at 70 °C for 1 hour and then heated at 100 °C for 3 hours, thereby obtaining a sheet-like cured product with a thickness of 2 mm. For this cured product, the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement methods.

[0161] [Comparative Example 16]

[0162] In Comparative Example 16, instead of using the cyclic siloxane (A) used in Example 17, a linear siloxane (a1) having a plurality of vinyl groups as the first functional group was used, and the compounding amounts of the respective materials were set to the compounding amounts shown in Table 8. Except for this, the operation was the same as in Example 17 to obtain the silicone resin composition of Comparative Example 16. It should be noted that the total ratio of the number of silicon hydride groups as the second functional group to the number of vinyl groups as the first functional group (second functional group / first functional group) in each constituent component was made 1.2 in the same manner as in Example 17, and the molar ratio of the linear polymer (C) to the linear polysiloxane (B) [(amount of substance of (C) / (amount of substance of (B))] was also made 0.5 in the same manner as in Example 17 to adjust the compounding amounts of the respective constituent components. After the obtained uncured silicone resin composition was calendered and formed into a sheet having a thickness of 2 mm, it was preheated at 70°C for 1 hour in a hot air oven (WFO-520W manufactured by Tokyo Science Instrument Co., Ltd.), and then heated at 100°C for 3 hours to obtain a sheet-like cured product having a thickness of 2 mm. For this cured product, the elongation at break (Eb) and the complex elastic modulus G were measured and evaluated according to the above-mentioned measurement method. ＊ The measurement and evaluation were carried out.

[0163] [Examples 18 and 19]

[0164] In Examples 18 and 19, a silicone resin composition containing a functional filler (E) in addition to the cyclic siloxane (A), the linear polysiloxane (B), and the linear polymer (C) was prepared. As the functional filler (E), the fumed silica (E1) shown in Table 2, which is a thixotropic filler, was used. In the examples, the cyclic siloxane (A) was always the cyclic trisiloxane (A1-1) having vinyl as the first functional group, and the linear polymer (C) was always the polydimethylsiloxane (C2) having vinyl at both ends. However, in Example 18, the polysiloxane (B1) having mercaptopropyl at both ends as the linear polysiloxane (B) and the photoinitiator (D1) were used, and in Example 19, the polydimethylsiloxane (B3) having silicon hydride at both ends as the linear polysiloxane (B) and the thermal curing catalyst (D2) were used. For the silicone resin composition of Example 18, a sheet-like cured product was prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G were measured and evaluated according to the above-mentioned measurement method. ＊ In addition, for the silicone resin composition of Example 19, a sheet-like cured product was prepared by a thermal curing reaction in the same order as in Example 17, and the elongation at break (Eb) and the complex elastic modulus G were measured and evaluated according to the above-mentioned measurement method. ＊ The measurement and evaluation were carried out.

[0165] [Comparative Examples 17 and 18]

[0166] In Comparative Examples 17 and 18, instead of using the cyclic siloxane (A) used in Examples 18 and 19, a linear siloxane (a1) having a plurality of vinyl groups as the first functional group was used, and the compounding amounts of the respective materials were set to the compounding amounts shown in Table 8. Except for this, the same operations as in the corresponding Examples 18 and 19 were performed to obtain silicone resin compositions containing the functional filler (E) of Comparative Examples 17 and 18. For the silicone resin composition of Comparative Example 17, a sheet-like cured product was prepared in the same order as in Example 18, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement methods. In addition, for the silicone resin composition of Comparative Example 18, a sheet-like cured product was prepared in the same order as in Example 19, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement methods.

[0167] [Comparative Examples 19 to 22]

[0168] In this comparative example, among the respective constituent components, the polydimethylsiloxane (C1) of the linear polymer (C) material used in Example 1 was replaced with polydimethylsiloxanes (C2 to C4) having various chain lengths shown in Table 2. In addition, the same materials as in Example 1 were used, and the compounding amounts were changed to the compounding amounts shown in Table 9. Except for this, the same operations as in Example 1 were performed to obtain the silicone resin compositions of Comparative Examples 19 to 22. For the obtained silicone resin compositions, sheet-like cured products were prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement methods. In Comparative Examples 19 to 22, for the silicone resin compositions of Comparative Examples 19 to 20 and 22, the prepared sheet-like cured products did not maintain the shape as the measurement sample when measuring various physical properties, so the elongation at break Eb and the complex elastic modulus G ＊ could not be measured. In addition, for the silicone resin composition of Comparative Example 21, the value of the elongation at break (%) was less than 200%, so it was judged as unqualified (×).

[0169] [Comparative Example 23]

[0170] In this comparative example, among the respective constituent components, a branched siloxane (a2) having a T unit having a plurality of vinyl groups as the first functional group was used instead of the cyclic siloxane (A) to obtain a silicone resin composition. The respective constituent components and their compounding amounts are shown in Table 9. For the obtained silicone resin composition, a sheet-like cured product was prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊Measurement and evaluation. Compared with the corresponding Example 6, the value of the elongation at break (%) is a lower value.

[0171] [Examples 20 to 23]

[0172] In Examples 20 to 23, among the respective components, each silicone resin composition was prepared in the same manner as in Example 12 without using the linear polymer (C) material. As shown in Table 10, in the examples, the cyclic siloxane (A) used was the cyclic trisiloxane (A1-1) having a vinyl group as the first functional group. However, in Examples 20 and 21, a polydimethylsiloxane (B1 or B2) having mercaptopropyl groups at both ends as the linear polysiloxane (B) and a photoinitiator (D1) were used, and in Examples 22 and 23, a polydimethylsiloxane (B4) having hydrosilyl groups at both ends as the linear polysiloxane (B) and a heat curing catalyst (D2) were used. For the silicone resin compositions of Examples 20 and 21, sheet-like cured products were prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated. In addition, for the silicone resin compositions of Examples 22 and 23, sheet-like cured products were prepared by a heat curing reaction in the same order as in Example 17, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated.

[0173] [Comparative Examples 24 to 27]

[0174] In Comparative Examples 24 to 27, instead of using the cyclic siloxane (A) used in Examples 20 to 23, a linear siloxane (a1) having a plurality of vinyl groups as the first functional group was used, and the compounding amounts of the respective materials were set to the compounding amounts shown in Table 10. Otherwise, the same operations as in the corresponding Examples 20 to 23 were performed to obtain the silicone resin compositions of Comparative Examples 24 to 27. For the silicone resin compositions of Comparative Examples 24 and 25, sheet-like cured products were prepared by a photocuring reaction in the same order as in Examples 20 and 21, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated. In addition, for the silicone resin compositions of Comparative Examples 26 and 27, sheet-like cured products were prepared by a heat curing reaction in the same order as in Examples 22 and 23, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated.

[0175] [Examples 24, 25]

[0176] In Examples 24 and 25, as the cyclic siloxane (A), cyclic trisiloxane (A3) having a mercaptopropyl group as the first functional group and cyclic trisiloxane (A2) having a silane hydrogen group as the first functional group shown in Table 2 were used respectively. As shown in Table 11, in the examples, polydimethylsiloxane (B5) having vinyl groups at both ends was used as the linear polysiloxane (B). However, in Example 24, a photopolymerization initiator (D1) was added, and in Example 25, a thermal curing catalyst (D2) was added. For the silicone resin composition of Example 24, a sheet-shaped cured product was prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement method. In addition, for the silicone resin composition of Example 25, a sheet-shaped cured product was prepared by a thermal curing reaction in the same order as in Example 17, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement method.

[0177] [Comparative Examples 28 and 29]

[0178] In Comparative Examples 28 and 29, a linear siloxane (a3) having a plurality of mercaptopropyl groups as the first functional group or a linear siloxane (a4) having a silane hydrogen group as the first functional group was used instead of the cyclic siloxane (A), and the compounding amounts of the respective materials were set to the compounding amounts shown in Table 11. Except for this, the same operations as in the corresponding Examples 24 and 25 were performed to obtain the silicone resin compositions of Comparative Examples 28 and 29. For the silicone resin composition of Comparative Example 28, a sheet-shaped cured product was prepared by a photocuring reaction in the same order as in Example 24, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement method. In addition, for the silicone resin composition of Comparative Example 29, a sheet-shaped cured product was prepared by a thermal curing reaction in the same order as in Example 25, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement method.

[0179] [Example 26]

[0180] In this example, a silicone resin composition containing a functional filler (E) in addition to the cyclic siloxane (A) and the linear polysiloxane (B) was prepared. As the functional filler (E), fumed silica (E1) shown in Table 2, which is a thixotropic filler, was used. The silicone resin composition of Example 26 was prepared with the materials and compounding amounts shown in Table 11. A sheet-shaped cured product was prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above measurement method.

[0181] [Comparative Example 30]

[0182] In Comparative Example 30, instead of using the cyclic siloxane (A) used in Example 26, a linear siloxane (a1) having a plurality of vinyl groups as the first functional group was used, and the compounding amounts of the respective materials were set to the compounding amounts shown in Table 11. Except for this, the operation was the same as that of the corresponding Example 26 to obtain a silicone resin composition containing the functional filler (E) of Comparative Example 30. A sheet-like cured product was prepared in the same order as in Example 26, and the elongation at break (Eb) and the complex elastic modulus G ＊ were measured and evaluated according to the above-mentioned measurement methods.

[0183] [Comparative Examples 31 and 32]

[0184] In this comparative example, in each constituent component, each silicone resin composition was prepared in the same manner as in Example 12 without using the linear polymer (C) material. As shown in Table 12, in the examples, the cyclic siloxane (A) was always the cyclic trisiloxane (A1-1) having a vinyl group as the first functional group, but in Comparative Example 31, a polydimethylsiloxane (B2) having mercaptopropyl groups at both ends as the linear polysiloxane (B) and a photopolymerization initiator (D1) were used, and in Comparative Example 32, a polydimethylsiloxane (B3) having silicon hydride groups at both ends as the linear polysiloxane (B) and a thermal curing catalyst (D2) were used. For the silicone resin composition of Comparative Example 31, a sheet-like cured product was prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G* were measured and evaluated according to the above-mentioned measurement methods. In addition, for the silicone resin composition of Comparative Example 32, a sheet-like cured product was prepared by a thermal curing reaction in the same order as in Example 17, and the elongation at break (Eb) and the complex elastic modulus G* were measured and evaluated according to the above-mentioned measurement methods. For the silicone resin compositions of Comparative Examples 31 and 32, the prepared sheet-like cured products did not maintain the shape of the measurement sample when measuring various physical properties, so the elongation at break Eb and the complex elastic modulus G ＊ could not be measured.

[0185] [Comparative Example 33]

[0186] In this comparative example, in each constituent component, a branched siloxane (a2) having a T unit having a plurality of vinyl groups as the first functional group was used instead of the cyclic siloxane (A) to obtain a silicone resin composition. The respective constituent components and their compounding amounts are shown in Table 12. For the obtained silicone resin composition, a sheet-like cured product was prepared in the same order as in Example 1, and the elongation at break (Eb) and the complex elastic modulus G ＊Determination and evaluation. Compared with the corresponding Example 21, the value of the elongation at break (%) is a lower value.

[0187] The results of Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 3 below, the results of Examples 5 to 8 and Comparative Examples 4, 7 to 9 are shown in Table 4 below, the results of Examples 9 to 11 and Comparative Examples 5, 10 to 11 are shown in Table 5 below, and the results of Example 12 and Comparative Example 6 are shown in Table 6 below. In addition, the results of Examples 13 to 16 and Comparative Examples 12 to 15 are shown in Table 7 below, the results of Examples 17 to 19 and Comparative Examples 16 to 18 are shown in Table 8 below, the results of Comparative Examples 19 to 23 are shown in Table 9 below, the results of Examples 20 to 23 and Comparative Examples 24 to 27 are shown in Table 10 below, the results of Examples 24 to 26 and Comparative Examples 28 to 30 are shown in Table 11 below, and the results of Comparative Examples 31 to 33 are shown in Table 12 below.

[0188] [Table 3]

[0189]

[0190] [Table 4]

[0191]

[0192] [Table 5]

[0193]

[0194] [Table 6]

[0195]

[0196] [Table 7]

[0197]

[0198] [Table 8]

[0199]

[0200] [Table 9]

[0201]

[0202] [Table 10]

[0203]

[0204] [Table 11]

[0205]

[0206] [Table 12]

[0207]

[0208] The results of Examples 1 to 26 and Comparative Examples 1 to 33 show that, by forming the silicone resin composition of the present invention and particularly using "cyclic siloxane (A)" as a constituent component, the ductility of the cured product (silicone viscoelastic material) is significantly improved. Among them, as the cyclic siloxane (A), cyclic trisiloxane (m = 3) and cyclic tetrasiloxane (m = 4) were used. As a result, both cyclic siloxanes showed high ductility. However, according to the results of Example 1 and Example 2, it can be seen that especially due to the use of cyclic trisiloxane with m = 3, the elongation at break value is so large as to exceed the measurement limit, and the ductility of the cured product is significantly improved. In addition, the relationship between the molecular chain length (molecular weight) of the linear polymer (C) in the constituent components and the elongation at break was studied. As a result, it was found that compared with the linear polymer (C) with a shorter molecular chain length (molecular weight: 9400), the elongation at break value of the linear polymer (C) with a longer molecular chain length (molecular weight: 28000, 72000) increased to exceed the measurement limit. In addition, the relationship between the total molecular chain length (total molecular weight) of the linear polysiloxane (B) and the linear polymer (C) bonded between the molecules of the cyclic siloxane (A) in the constituent components and the elongation at break was studied. As a result, it was found that the elongation at break value increased for those with a longer total molecular chain length (larger total molecular weight) of the linear polysiloxane (B) and the linear polymer (C). More specifically, the total molecular weight of the linear polysiloxane (B) and the linear polymer (C) is preferably adjusted to at least 20000 or more, more preferably adjusted to 30000 or more, and particularly preferably adjusted to 35000 or more.

[0209] Furthermore, the relationship between the value of [the number of second functional groups / the total number of first functional groups] of the constituent components of the silicone resin composition and the elongation at break was studied. As a result, it was found that when the total molecular chain length of the linear polysiloxane (B) and the linear polymer (C) is longer (larger total molecular weight; molecular weight of component (B): 4800, molecular weight of component (C): 28000, 72000), it is preferable to set [the number of second functional groups / the total number of first functional groups] to 1.4 or less, and particularly preferably set to 1 to 1.2 (Examples 1 to 4 and Comparative Examples 1 to 3, and Examples 9 to 11 and Comparative Example 5). On the other hand, it was found that when the total molecular chain length of the linear polysiloxane (B) and the linear polymer (C) is shorter (smaller total molecular weight; molecular weight of component (B): 4800, molecular weight of component (C): 9400), it is preferable to set [the number of second functional groups / the total number of first functional groups] to less than 1, and particularly preferably set to 0.8 or more and less than 1 (Examples 5 to 8 and Comparative Example 4).

[0210] In addition, in the relationship between the number ratio of [the number of second functional groups / (the total number of first functional groups)] of the components of the silicone resin composition in the three-component system composed of cyclic siloxane (A), linear polysiloxane (B), and linear polymer (C) and the elongation at break, from the results of Examples 1 to 11 and Examples 13 to 17, it can be seen that the effects of the present invention can be obtained when the number ratio of [the number of second functional groups / (the total number of first functional groups)] is in the range of 0.4 to 1.9. On the other hand, from the results of Comparative Examples 19 to 20, it can be seen that if the above-mentioned number ratio deviates from the above range, crosslinking cannot proceed sufficiently, and the cured product is difficult to maintain its shape under natural gravity, and a composition having the effects of the present invention cannot be obtained.

[0211] Furthermore, in the relationship between the value of the ratio of the amount of substance of the linear polymer (C) to the amount of substance of the linear polysiloxane (B) [(the amount of substance of (C)) / (the amount of substance of (B))] of the components of the silicone resin composition in the three-component system composed of cyclic siloxane (A), linear polysiloxane (B), and linear polymer (C) and the elongation at break, from the results of Examples 1 to 11 and Examples 13 to 17, it can be seen that the effects of the present invention can be obtained when the value of [(the amount of substance of (C)) / (the amount of substance of (B))] is in the range of 0.4 or more and less than 0.6. On the other hand, from the results of Comparative Examples 21 to 22, it can be seen that if the value of [(the amount of substance of (C)) / (the amount of substance of (B))] is less than 0.4, the ductility becomes insufficient, and if it is 0.6 or more, crosslinking cannot proceed sufficiently, and the cured product is difficult to maintain its shape under natural gravity, and a composition having the effects of the present invention cannot be obtained.

[0212] In addition, from the results of Example 12 and Comparative Example 6, it can be seen that when the silicone resin composition is composed of a two-component system of cyclic siloxane (A) and linear polysiloxane (B) without the linear polymer (C), the elongation at break value also increases. Here, if the relationship between the number ratio of [the number of second functional groups / (the total number of first functional groups)] of the components of the silicone resin composition in the two-component system composed of cyclic siloxane (A) and linear polysiloxane (B) and the elongation at break is studied, from the results of Example 12 and Examples 20 to 23, it can be seen that the effects of the present invention can be obtained when the number ratio of [the number of second functional groups / (the total number of first functional groups)] is in the range of 0.4 to 2.0. On the other hand, from the results of Comparative Examples 31 to 32, it can be seen that if the above-mentioned number ratio deviates from the above range, crosslinking cannot proceed sufficiently, and the cured product is difficult to maintain its shape under natural gravity, and a composition having the effects of the present invention cannot be obtained.

[0213] Furthermore, from the results of Examples 1 to 16, Examples 20 to 21, Example 17, Examples 22 to 23, and Examples 24 to 25, it can be seen that in addition to vinyl, the second functional group of the linear polysiloxane (B) constituting the silicone resin composition of the present invention may also be a mercaptoalkyl group or a sihydryl group, and as long as it is a functional group capable of undergoing an addition reaction with the first functional group of the cyclic siloxane (A), a silicone resin composition achieving the effects of the present invention can be obtained.

[0214] In addition, from the results of Examples 24 to 25, it can be seen that even if the cyclic siloxane (A) constituting the silicone resin composition of the present invention is a compound represented by the general formula (2) or (3), a silicone resin composition achieving the effects of the present invention can be obtained. In addition, from the results of Examples 1 to 23, Example 26, and Examples 24 to 25, it can be seen that in addition to vinyl, the first functional group of the cyclic siloxane (A) may also be a mercaptoalkyl group or a sihydryl group, and as long as it is a functional group capable of undergoing an addition reaction with the second functional group of the linear polysiloxane (B), a silicone resin composition achieving the effects of the present invention can be obtained.

[0215] Furthermore, from the results of Examples 18 to 19 and Example 26, it can be seen that the silicone resin composition of the present invention may contain a functional filler (E), and even if it contains the functional filler (E), the effects of the present invention can be obtained.

[0216] On the other hand, from the results of Comparative Examples 23 and 33 in which a branched siloxane (a2) having a plurality of first functional groups is used instead of the cyclic siloxane (A) having a plurality of first functional groups, no improvement effect in ductility is shown. From this, it can be seen that it is important to use a cyclic siloxane as a constituent of the silicone resin composition.

[0217] Furthermore, it can be seen that by configuring the silicone resin composition of the present invention, the complex elastic modulus G of the cured product ＊ also shows a value of 2200 or more including a low-hardness region capable of minimally maintaining the shape, and can be adjusted in a wide range of at least up to 72400. Therefore, a cured product having a function of high damping can be obtained.

[0218] Based on the results of the above examples, by configuring the silicone resin composition of the present invention, a cured product having excellent ductility and high deformation followability can be obtained. Therefore, the cured product of the present invention can be suitably used as a damping material, a potting material, a heat dissipation material, a sealing material, a coating material, a shockproof material, a vibration damping material, and an optical adhesive (OCR, OCA). Further, it is shown that the complex elastic modulus of the cured product is also excellent and shows high damping, so it can be particularly suitably used as a damping member.

[0219] The present invention is not limited to the above-described embodiments or examples, and various modified designs are also included in the technical scope without departing from the gist of the invention described in the claims.

[0220] Industrial Applicability

[0221] The silicone resin composition of the present invention forms a cured product having high ductility, and is therefore useful as a damping material, potting material, and heat dissipation material for electrical and electronic components, and has broad application prospects in industries such as electronic devices and semiconductor devices.

Claims

1. A silicone resin composition, characterized in that, Comprising: A cyclic siloxane (A) having a first functional group; A linear polysiloxane (B) having second functional groups capable of undergoing an addition reaction with the first functional group at both ends of the molecular chain; A linear polymer (C) having the first functional group at both ends of the molecular chain; And A photopolymerization initiator or a thermosetting catalyst (D) that initiates or promotes the addition reaction between the first functional group and the second functional group, The cyclic siloxane (A) is a cyclic siloxane represented by the following general formula (1), general formula (2) or general formula (3), In General Formula (1), General Formula (2), and General Formula (3), R a or said R a SiR formed by bonding with the silicon atom of the siloxane chain a represents the first functional group, and R b each independently represents an alkyl group or a phenyl group, m represents an integer of 3 to 5, in General Formula (2) and General Formula (3), n represents an integer of 1 to 1000, and in General Formula (3), Y represents an alkylene group The ratio of the number of the second functional groups of the linear polysiloxane (B) to the total number of the first functional groups of the cyclic siloxane (A) and the linear polymer (C) is 0.4 to 1.9, The molar ratio of the linear polymer (C) to the linear polysiloxane (B) is 0.4 or more and less than 0.

6.

2. A silicone resin composition, characterized in that, Comprising: A cyclic siloxane (A) having a first functional group; A linear polysiloxane (B) having second functional groups capable of undergoing an addition reaction with the first functional group at both ends of the molecular chain; and A photopolymerization initiator or a thermosetting catalyst (D) that initiates or promotes the addition reaction between the first functional group and the second functional group, The cyclic siloxane (A) is a cyclic siloxane represented by the following general formula (1), general formula (2) or general formula (3), In General Formula (1), General Formula (2), and General Formula (3), R a or said R a SiR formed by bonding with the silicon atom of the siloxane chain a represents the first functional group, and R b each independently represents an alkyl group or a phenyl group, m represents an integer of 3 to 5, in General Formula (2) and General Formula (3), n represents an integer of 1 to 1000, and in General Formula (3), Y represents an alkylene group. The ratio of the number of the second functional groups of the linear polysiloxane (B) to the number of the first functional groups of the cyclic siloxane (A) is 0.4 to 2.

0.

3. The organosilicon resin composition according to claim 1 or 2, wherein One of the first functional group and the second functional group is an alkenyl group, The other of the first functional group and the second functional group is a mercaptoalkyl group or a sihydro group.

4. The silicone resin composition according to claim 3, wherein, The cyclic siloxane (A) is a cyclic trisiloxane in which m represents an integer 3 in the general formula (1), general formula (2) or general formula (3).

5. The organosilicon resin composition according to claim 4, wherein The first functional group is an alkenyl group, The second functional group is a mercaptoalkyl group or a sihydro group.

6. The silicone resin composition according to claim 5, characterized in that, The alkenyl group is a vinyl group.

7. The silicone resin composition according to claim 1 or 2, characterized in that, It further comprises at least one functional filler (E) selected from the group consisting of thixotropic fillers, thermally conductive fillers, electrically conductive fillers, magnetic fillers and dielectric fillers.

8. The silicone resin composition according to claim 1, wherein, The linear polymer (C) is an organopolysiloxane represented by the following general formula (4), In general formula (4), R a or said R a SiR formed by bonding with the silicon atom at the end of the siloxane chain a represents the first functional group, and R c each independently represents an alkyl group or a phenyl group, and p represents an integer of 25 to 2000.

9. A cured product obtained by curing the organosilicon resin composition according to claim 1 or 2.

10. The cured product according to claim 9, wherein The cured product has an elongation at break Eb of 200% or more according to JIS K6251:2071 and a complex elastic modulus of 1000 to 150000 according to JIS K7244-10.

11. A damping member composed of the cured product according to claim 9.

12. An electronic device comprising the damping member according to claim 11.

13. A heat sink composed of the cured product according to claim 9.

14. An electronic device, which includes the heat sink described in claim 13.

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