Photocurable composition, cured product thereof, and method for producing the cured product

Abstract

Provided is a photocurable composition comprising a silsesquioxane derivative that is indicated by formula (1) and a hydrosilylation catalyst that contains a transition metal.

Description

[Technical field]

[0001] The present disclosure relates to a photocurable composition, a cured product thereof, and a method for producing the cured product, and belongs to the technical fields of heat-resistant materials, insulating materials, electronic materials, and automobiles. More specifically, the present disclosure relates to a photocurable composition containing an organosilicon compound having a hydrosilylation-reactive carbon-carbon unsaturated group and a hydrosilyl group, and a hydrosilylation catalyst. The cured product of the photocurable composition is useful as a heat-resistant insulating material. [Background technology]

[0002] 2. Description of the Related Art In recent years, with the miniaturization, high integration and high performance of electronic devices and automobile parts, there has been an increasing demand for high heat resistance of various protective films and insulating films used therein. From the viewpoints of workability, optical properties, chemical resistance, heat resistance, weather resistance, etc., siloxane-based compounds such as silicone, which are organic-inorganic composite materials, are being used, and addition-curing silsesquioxane derivatives have attracted particular attention from the viewpoints of high heat resistance and workability.

[0003] International Publication No. 2005 / 010077 discloses a thermosetting, highly heat-resistant silsesquioxane derivative in which a carbon-carbon unsaturated bond group and a hydrosilyl group are both bonded to a silicon atom having a T structure in the same molecule.

[0004] International Publication No. 2009 / 066608 discloses a thermosetting, highly heat-resistant silsesquioxane derivative having a carbon-carbon unsaturated bond group and a hydrosilyl group in the same molecule and having a T structure, a D structure, and an M structure. Summary of the Invention [Problem to be solved by the invention]

[0005] However, in order to cure the silsesquioxane derivatives disclosed in WO 2005 / 010077 and WO 2009 / 066608 through hydrosilylation crosslinking, a heat treatment is essential, and therefore the substrate to which it is applied is limited to one that can withstand the heating temperature. In addition, long periods of heating are required for curing, resulting in problems in productivity. According to one embodiment of the present invention, it is possible to provide a photocurable composition containing a silsesquioxane derivative that has excellent curability and can be applied to various substrates, a cured product thereof, and a method for producing the cured product. [Means for solving the problem]

[0006] The present invention includes the following aspects [1] to

[11] . [1] A photocurable composition comprising a silsesquioxane derivative represented by the following formula (1) and a hydrosilylation catalyst containing a transition metal: [ka] [In formula (1), R 1 is an organic group having 2 to 12 carbon atoms and a hydrosilylation-reactive carbon-carbon unsaturated bond, R 2 is at least one selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms, Multiple R's 3 and R 4 each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, and an organic group having 2 to 12 carbon atoms and a hydrosilylation reactive carbon-carbon unsaturated bond, Multiple R's 3 may be the same or different, Multiple R's 4 may be the same or different, u, v, w and x are each independently 0 or a positive number, at least one of which is a positive number; y and z each independently represent 0 or a positive number; 0≦y / (u+v+w+x)≦2.0, 0≦z / (u+v+w+x)≦2.0, However, when v=0, there are multiple R 3 and R 4 At least one of the R 3 and R 4 At least one of the above is an organic group having 2 to 12 carbon atoms and a hydrosilylation-reactive carbon-carbon unsaturated bond.] [2] The photocurable composition according to [1], wherein the ratio of the number of hydrogen atoms bonded to silicon atoms to one organic group having a hydrosilylation reactive carbon-carbon unsaturated bond present in the silsesquioxane derivative is 0.5 to 5.0. [3] The photocurable composition according to [1] or [2], wherein the content of the transition metal is 0.1 to 30,000 ppm by weight based on 100 parts by weight of the silsesquioxane derivative. [4] The photocurable composition according to any one of [1] to [3], wherein the transition metal is a platinum group metal. [5] The hydrosilylation catalyst containing a transition metal is selected from the group consisting of β-diketonato platinum complexes, (η-cyclopentadienyl)trialkyl platinum complexes, (η 4 The photocurable composition according to any one of [1] to [4], wherein the platinum complex is at least one selected from the group consisting of (1,5-cyclooctadiene)diaryl platinum complexes and dialkyl azodicarboxylate platinum complexes. [6] The photocurable composition according to any one of [1] to [5], further comprising a heat resistance improver. [7] A cured product obtained by curing the photocurable composition according to any one of [1] to [6]. [8] The cured product according to [7], having a dielectric constant of 4.0 or less at 1 MHz. [9] The cured product according to [7] or [8], which has a 5% weight loss temperature in air of 300°C or higher in thermogravimetry.

[10] The cured product according to any one of [7] to [9], which is an insulating film.

[11] A method for producing a cured product, comprising the step of curing the photocurable composition according to any one of [1] to [6] by irradiating it with ultraviolet light. Effect of the Invention

[0007] According to one embodiment of the present invention, it is possible to provide a photocurable composition containing a silsesquioxane derivative that has excellent curability and can be applied to various substrates, a cured product thereof, and a method for producing the cured product. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The present disclosure relates to a photocurable composition, a cured product thereof, and a method for producing the cured product. The present disclosure will be described in detail below. In addition, unless otherwise specified, "%" means "% by weight", "parts" means "parts by weight", and "ppm" means "ppm by weight". In addition, in this disclosure, the description "lower limit to upper limit" indicating a numerical range means "not less than the lower limit, not more than the upper limit", and the description "upper limit to lower limit" means "not more than the upper limit, not less than the lower limit". In other words, it represents a numerical range including the upper limit and the lower limit. Furthermore, in this disclosure, a combination of two or more of the preferred embodiments described below is also a preferred embodiment. In the present disclosure, the term "process" refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0009] The silsesquioxane derivative, the method for producing the silsesquioxane derivative, the hydrosilylation catalyst, the photocurable composition, the cured product thereof, the method for producing the cured product, and uses will be described below.

[0010] 1. Silsesquioxane derivatives The silsesquioxane derivative according to the present disclosure is a silsesquioxane derivative represented by the following formula (1): The silsesquioxane derivative represented by the following formula (1) has an organic group having a carbon-carbon unsaturated bond capable of undergoing a hydrosilylation reaction and a hydrosilyl group in the same molecule.

[0011] [ka]

[0012] The structural units that the silsesquioxane derivative according to the present disclosure can have are referred to as structural units (a) to (f) as follows, and are described below.

[0013] Structural unit (a): (SiO 4 / 2 ) u

[0014] [ka]

[0015] Structural unit (b): (HSiO 3 / 2 ) v

[0016] [ka]

[0017] Structural unit (c): (R 1 SiO 3 / 2 ) w

[0018] [ka]

[0019] Structural unit (d): (R 2 SiO 3 / 2 ) x

[0020] [ka]

[0021] Structural unit (e): (R 3 2SiO 2 / 2 ) y

[0022] [ka]

[0023] Structural unit (f): (R 4 3SiO 1 / 2 ) z

[0024] [ka]

[0025] The silsesquioxane derivative according to the present disclosure can contain the above-mentioned structural units (a) to (f). In formula (1), u, v, w and x are each independently 0 or a positive number, provided that at least one of them is a positive number, and y and z are each independently 0 or a positive number, provided that 0≦y / (u+v+w+x)≦2.0 and 0≦z / (u+v+w+x)≦2.0. That is, u, v, w, x, y, and z in formula (1) represent the molar ratio of each of the constituent units. In addition, in formula (1), u, v, w, x, y, and z represent the relative molar ratio of each of the constituent units contained in the silsesquioxane derivative according to the present disclosure represented by formula (1). That is, the molar ratio is the relative ratio of the total number of each of the constituent units represented by formula (1). The molar ratio can be determined from the NMR (nuclear magnetic resonance) analysis value of the silsesquioxane derivative according to the present disclosure. In addition, when the reaction rate of each raw material of the present silsesquioxane derivative is clear or the yield is 100%, it can be determined from the amount of the raw material charged.

[0026] Each of the structural units (c), (d), (e) and (f) in formula (1) may be one type or two or more types. The sequence in formula (1) indicates the composition of the structural units, but does not mean the sequence. Therefore, the condensation form of the structural units in the silsesquioxane derivative according to the present disclosure does not necessarily have to be the sequence of formula (1).

[0027] 1-1. Structural unit (a): (SiO 4 / 2 ) u The structural unit (a) is O per silicon atom. 1 / 2 This is a so-called Q unit, which has four silicon atoms (two oxygen atoms). 1 / 2 It means a unit having four. The proportion of the structural unit (a) in the silsesquioxane derivative according to the present disclosure is not particularly limited, but in consideration of the viscosity of the photocurable composition according to the present disclosure and the flexibility of the cured product thereof, the molar ratio (u / (u+v+w+x+y+z)) of the structural unit to all structural units is preferably 0.5 or less, more preferably 0.4 or less, even more preferably 0.3 or less, and even more preferably 0. Here, a molar ratio of 0 means that the structural unit is not included, and the same applies hereinafter.

[0028] 1-2. Structural unit (b): (HSiO 3 / 2 ) v The structural unit (b) is O per silicon atom. 1 / 2 The unit has three oxygen atoms (1.5 oxygen atoms) and is called a T unit, and has a hydrogen atom bonded to a silicon atom. 1 / 2 It means a unit having three. That is, the structural unit (b) has a hydrosilyl group capable of undergoing a hydrosilylation reaction. The proportion of the structural unit (b) in the silsesquioxane derivative according to the present disclosure is not particularly limited, but in consideration of the heat resistance, oxidation resistance, weather resistance, and insulating properties of the photocurable composition of the present disclosure and the cured product thereof, the molar ratio (v / (u+v+w+x+y+z)) of the structural unit (b) to all structural units is preferably 0 to 0.7, and in consideration of the heat resistance, oxidation resistance, and weather resistance as an insulating film, it is more preferably 0 to 0.1.

[0029] 1-3. Constitutional unit (c): (R 1 SiO 3 / 2 ) w The structural unit (c) is O per silicon atom. 1 / 2 A T unit having three (1.5 oxygen atoms) R bonded to a silicon atom 1 It is equipped with: R 1 represents an organic group having 2 to 12 carbon atoms and a hydrosilylation-reactive carbon-carbon unsaturated bond. 1 is preferably a functional group having a carbon-carbon double bond or a carbon-carbon triple bond capable of hydrosilylation reaction. Such an organic group R 1 Specific examples of the alkyl group include, but are not limited to, a vinyl group, an orthostyryl group, a methstyryl group, a parastyryl group, an acryloyloxymethyl group, a methacryloyloxymethyl group, a 2-acryloyloxyethyl group, a 2-methacryloyloxyethyl group, a 3-acryloyloxypropyl group, a 3-methacryloyloxypropyl group, an 8-acryloyloxyoctyl group, an 8-methacryloyloxyoctyl group, a 1 Examples include 3-propenyl group, 2-propenyl group, 1-methylethenyl group, 1-butenyl group, 3-butenyl group, 1-pentenyl group, 4-pentenyl group, 3-methyl-1-butenyl group, 1-phenylethenyl group, 2-phenylethenyl group, ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 3-butynyl group, 1-pentynyl group, 4-pentynyl group, 3-methyl-1-butynyl group, and phenylbutynyl group. From the viewpoints of hydrosilylation reactivity and the heat resistance, oxidation resistance and / or weather resistance of the cured product, 1 is preferably a hydrocarbon group having a carbon-carbon double bond, more preferably a vinyl group and a 2-propenyl group (allyl group) having a small number of carbon atoms, or an aromatic orthostyryl group, metastyryl group and parastyryl group, and further preferably a vinyl group. The silsesquioxane derivative represented by formula (1) as a whole comprises an organic group R 1 In this case, all of the organic groups R 1 may be the same as or different from each other. For example, when different, a vinyl group and a parastyryl group may be present.

[0030] The proportion of the structural unit (c) in the silsesquioxane derivative according to the present disclosure is not particularly limited, but in consideration of the heat resistance, oxidation resistance, weather resistance, and insulating properties of the photocurable composition according to the present disclosure and the cured product thereof, the molar ratio (w / (u+v+w+x+y+z)) of the structural unit (c) to all structural units is preferably 0 to 0.5, and more preferably 0.1 to 0.3.

[0031] 1-4. Structural unit (d): (R 2 SiO 3 / 2 ) x The structural unit (d) is O per silicon atom. 1 / 2 A T unit having three (1.5 oxygen atoms) R bonded to a silicon atom 2 It is equipped with: R 2 is at least one selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. The structural unit (d) differs from the structural units (b) and (c) described above in that it does not contain a hydrogen atom and does not contain an organic group having a carbon-carbon unsaturated bond capable of hydrosilylation reaction. The structural unit (d) basically forms three siloxane bonds per silicon atom in the photocurable composition and its cured product, but does not form crosslinks by hydrosilylation reaction, and has one organic group with an appropriate number of carbon atoms per silicon atom, which contributes to improving the heat resistance, oxidation resistance, insulating properties, adhesion to substrates, and / or flexibility of the photocurable composition and its cured product of the present disclosure. In addition, the amount of hydrogen atoms remaining in the cured product of the photocurable composition of the present disclosure can be reduced.

[0032] The alkyl group having 1 to 10 carbon atoms may be either an aliphatic group or an alicyclic group, and may be either linear or branched. Although not particularly limited, examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. From the viewpoint of heat resistance, preferred examples include a methyl group and an ethyl group, and more preferred is a methyl group.

[0033] The aryl group having 6 to 10 carbon atoms is not particularly limited, and examples thereof include a phenyl group, a group in which one or more hydrogen atoms of a phenyl group are substituted with an alkyl group having 1 to 4 carbon atoms, and a naphthyl group, etc. From the viewpoint of heat resistance, a phenyl group is preferable.

[0034] The aralkyl group having 7 to 10 carbon atoms is not particularly limited, and examples thereof include a group in which one hydrogen atom of an alkyl group having 1 to 4 carbon atoms is substituted with an aryl group such as a phenyl group. Examples thereof include a benzyl group and a phenethyl group, and from the viewpoint of heat resistance, a benzyl group is preferred.

[0035] The silsesquioxane derivative represented by formula (1) as a whole comprises an organic group R 2 In this case, all of the organic groups R 2 may be the same as or different from each other.

[0036] The proportion of the structural unit (d) in the silsesquioxane derivative according to the present disclosure is not particularly limited, but the molar ratio (x / (u+v+w+x+y+z)) of the structural unit (d) to all structural units is preferably 0 to 0.7 in consideration of the heat resistance, oxidation resistance, weather resistance, and insulating properties of the photocurable composition of the present disclosure and the cured product thereof, and more preferably 0.3 to 0.6 in consideration of the heat resistance, oxidation resistance, and weather resistance as an insulating film.

[0037] 1-5. Structural unit (e): (R 3 2 SiO 2 / 2 ) y The structural unit (e) is O per silicon atom. 1 / 2 This is a so-called D unit, which has two silicon atoms (one oxygen atom). 1 / 2 It means a unit having two. Multiple R's 3 are each independently at least one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, and an organic group having 2 to 12 carbon atoms and a carbon-carbon unsaturated bond capable of hydrosilylation, 3 may be the same or different. Each of these substituents is R 1 and R of the structural unit (d) 2 Examples of the substituents include those exemplified for the above. The structural unit (e) is a D unit, and therefore contributes to lowering the viscosity of the photocurable composition of the present disclosure and improving the flexibility, heat resistance, oxidation resistance, and / or insulating properties of the cured product thereof. From the viewpoints of heat resistance, availability of raw materials, and flexibility of the cured product, there are several R 3 are preferably each independently a methyl group or a phenyl group.

[0038] The proportion of the structural unit (e) in the silsesquioxane derivative according to the present disclosure is not particularly limited, but in consideration of the low viscosity of the photocurable composition according to the present disclosure and the weather resistance and flexibility of the cured product thereof, the molar ratio (y / (u+v+w+x)) to the total Q units and T units is preferably 0≦y / (u+v+w+x)≦2.0, more preferably 0.1 to 1.0, and even more preferably 0.1 to 0.5. However, when v=0, if a plurality of R 3 and multiple R in the structural unit (f) described below. 4 At least one of the R 3 and R 4 At least one of them is an organic group having 2 to 12 carbon atoms and a hydrosilylation reactive carbon-carbon unsaturated bond.

[0039] 1-6. Structural unit (f): (R 4 3 SiO 1 / 2 ) z The structural unit (f) is O per silicon atom. 1 / 2 The M unit has one silicon atom (0.5 oxygen atoms). 1 / 2 It means a unit having one. Multiple R's 4 are each independently at least one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, and an organic group having 2 to 12 carbon atoms and a carbon-carbon unsaturated bond capable of hydrosilylation, 4 may be the same or different. Each of these substituents is R 1 and R of the structural unit (d) 2 Examples of the substituents include those exemplified for the above. The structural unit (f) is an M unit, and therefore contributes to lowering the viscosity of the photocurable composition of the present disclosure and improving the flexibility and / or insulating properties of the cured product thereof.

[0040] The M unit in the silsesquioxane derivative according to the present disclosure has one siloxane bond bonded to a silicon atom, and therefore has high flexibility. 4 are each independently a hydrogen atom or an organic group having a hydrosilylation-reactive carbon-carbon unsaturated bond, the hydrosilylation reactivity is generally higher than when these groups are bonded to the T unit and the D unit, and the curing reaction proceeds smoothly. 4 are each independently a hydrogen atom or an organic group having 2 to 12 carbon atoms and a hydrosilylation-reactive carbon-carbon unsaturated bond, the M unit in the cured product is incorporated into the skeleton of the cured product via two bonds, a siloxane bond and a hydrosilylation crosslink, so that R 4 In this case, the heat resistance, weather resistance, etc. of the cured product are improved as compared to when the copolymer does not contain such a group. Therefore, the three R 4 Among these, at least one is preferably a hydrogen atom or an organic group having 2 to 12 carbon atoms and a hydrosilylation-reactive carbon-carbon unsaturated bond. From the viewpoints of heat resistance and easy availability of raw materials, the organic group having 2 to 12 carbon atoms and a hydrosilylation-reactive carbon-carbon unsaturated bond is preferably a vinyl group.

[0041] In addition, from the viewpoint of improving the flexibility, heat resistance, and weather resistance of the cured product, the three R 4 Among these, at least one is preferably at least one selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. From the viewpoints of heat resistance, availability of raw materials, and imparting flexibility to the cured product, preferred are a methyl group and a phenyl group.

[0042] The proportion of the structural unit (f) in the silsesquioxane derivative according to the present disclosure is not particularly limited, but in consideration of the low viscosity of the photocurable composition according to the present disclosure and the weather resistance and flexibility of the cured product thereof, the molar ratio (z / (u+v+w+x)) to the total number of Q units and T units is preferably 0≦z / (u+v+w+x)≦2.0, more preferably 0.1 to 1.0, and even more preferably 0.1 to 0.5. However, when v=0, R in the above-mentioned structural unit (e) 3 and R 4 At least one of the groups is a hydrogen atom, and when w=0, R 3 and R 4 At least one of them is an organic group having 2 to 12 carbon atoms and a hydrosilylation reactive carbon-carbon unsaturated bond.

[0043] 1-7.Other structural units (g) The silsesquioxane derivative according to the present disclosure further comprises (R 5 O 1 / 2 ) (hereinafter referred to as structural unit (g)). Here, R 5 is a hydrogen atom and / or an alkyl group having 1 to 6 carbon atoms, which may be either an aliphatic group or an alicyclic group, and may be either linear or branched. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.

[0044] This constitutional unit is either an alkoxy group, which is a hydrolyzable group contained in the raw material monomer described below, or an alkoxy group generated by substitution of a hydrolyzable group of the raw material monomer with an alcohol contained in the reaction solvent, which remains in the molecule without undergoing hydrolysis and polycondensation, or a hydroxyl group which remains in the molecule after hydrolysis without undergoing polycondensation.

[0045] 1-8.Functional groups for hydrosilylation reactions The ratio of the number of hydrogen atoms bonded to silicon atoms to one organic group having a hydrosilylation reactive carbon-carbon unsaturated bond present in the silsesquioxane derivative according to the present disclosure is not particularly limited, but from the viewpoints of the heat resistance, oxidation resistance, and weather resistance of the cured product, it is preferably 0.5 to 5.0, more preferably 0.8 to 3.0, and even more preferably 0.9 to 1.5.

[0046] 1-9.Molecular weight etc. The weight average molecular weight (hereinafter referred to as "Mw") of the silsesquioxane derivative according to the present disclosure is not particularly limited, but is preferably in the range of 300 to 30,000. Such a silsesquioxane derivative is liquid itself, has low viscosity suitable for handling, is easily soluble in organic solvents, the viscosity of the solution is easy to handle, and has excellent storage stability. Mw is more preferably 500 to 15,000, further preferably 700 to 10,000, and particularly preferably 1,000 to 5,000. In the present disclosure, Mw refers to a value obtained by converting the molecular weight measured by GPC (gel permeation chromatography) using polystyrene as a standard substance. The measurement conditions for Mw can be, for example, the measurement conditions in the Examples described below.

[0047] The state of the silsesquioxane derivative according to the present disclosure is not particularly limited, and examples thereof include liquid, solid, and semi-solid. It is preferably a liquid, and its viscosity is not particularly limited, and its viscosity at 25°C is preferably 1,000,000 mPa·s or less, more preferably 100,000 mPa·s or less, even more preferably 80,000 mPa·s or less, and particularly preferably 50,000 mPa·s or less. The lower limit of the viscosity is not particularly limited, and is, for example, 1 mPa·s. In this disclosure, the viscosity refers to a value measured at 25° C. using an E-type viscometer (a cone-plate type viscometer, for example, TVE22H type viscometer manufactured by Toki Sangyo Co., Ltd.).

[0048] 2. Method for producing silsesquioxane derivatives The silsesquioxane derivative according to the present disclosure can be produced by a known method. The method for producing the silsesquioxane derivative is disclosed in detail in WO 2005 / 01007, WO 2009 / 066608, WO 2013 / 099909, JP 2011-052170 A, JP 2013-147659 A, etc. as a method for producing polysiloxane.

[0049] The silsesquioxane derivative according to the present disclosure can be produced, for example, by the following method. That is, the method for producing a silsesquioxane derivative according to the present disclosure can include a condensation step in which a raw material monomer is subjected to a hydrolysis-polycondensation reaction in a suitable reaction solvent to give the structural unit in the above formula (1). In this condensation step, for example, a silicon compound having four siloxane bond forming groups (hereinafter referred to as "Q monomer") forming the structural unit (a) (Q unit), a silicon compound having three siloxane bond forming groups (hereinafter referred to as "T monomer") forming the structural units (b) to (d) (T unit), a silicon compound having two siloxane bond forming groups (hereinafter referred to as "D monomer") forming the structural unit (e) (D unit), and a silicon compound having one siloxane bond forming group (hereinafter referred to as "M monomer") forming the structural unit (f) (M unit) can be used.

[0050] The method for producing a silsesquioxane derivative according to the present disclosure preferably includes a distillation step of distilling off the reaction solvent, by-products, residual monomers, water, and the like from the reaction solution after subjecting raw material monomers to a hydrolysis / polycondensation reaction in the presence of a reaction solvent.

[0051] 2-1. Raw material monomer The siloxane bond-forming groups contained in the raw material monomers Q monomer, T monomer, D monomer, and M monomer are hydroxyl groups and / or hydrolyzable groups. Among these, examples of the hydrolyzable groups include halogeno groups, alkoxy groups, and siloxy groups. In the condensation step, the hydrolyzable groups are preferably alkoxy groups, more preferably alkoxy groups having 1 to 3 carbon atoms, because they have good hydrolysis properties and do not by-produce acids. In addition, in the M monomer, the hydrolyzable groups are preferably siloxy groups, because of the ease of obtaining raw materials, and disiloxanes consisting of two structural units (f) can be used.

[0052] In the condensation step, the siloxane bond forming groups of the Q monomer, T monomer and D monomer corresponding to each of the structural units are preferably alkoxy groups, and the siloxane bond forming groups contained in the M monomer are preferably alkoxy groups or siloxy groups. The monomers corresponding to each of the structural units may be used alone or in combination of two or more kinds.

[0053] Examples of the Q monomer that provides the structural unit (a) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane. Examples of the T monomer that provides the structural unit (b) include trimethoxysilane, triethoxysilane, tripropoxysilane, and trichlorosilane. Examples of T monomers that provide the structural unit (c) include trimethoxyvinylsilane, triethoxyvinylsilane, trichlorovinylsilane, allyltrimethoxysilane, (p-styryl)trimethoxysilane, (p-styryl)triethoxysilane, (3-methacryloyloxypropyl)trimethoxysilane, (3-methacryloyloxypropyl)triethoxysilane, (3-acryloyloxypropyl)trimethoxysilane, (3-acryloyloxypropyl)triethoxysilane, (8-methacryloyloxyoctyl)trimethoxysilane, and (8-acryloyloxyoctyl)trimethoxysilane. Examples of T monomers that provide the structural unit (d) include methyltrimethoxysilane, methyltriethoxysilane, methyltripoxysilane, methyltriisopropoxysilane, methyltrichlorosilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane. Examples of D monomers which give the structural unit (e) include dimethoxydimethylsilane, dimethoxydiethylsilane, diethoxydimethylsilane, diethoxydiethylsilane, dipropoxydimethylsilane, dipropoxydiethylsilane, dimethoxymethylphenylsilane, diethoxymethylphenylsilane, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxybenzylmethylsilane, diethoxybenzylmethylsilane, dichlorodimethylsilane, dimethoxymethylsilane, dimethoxyphenylsilane, dimethoxymethylvinylsilane, diethoxymethylsilane, diethoxyphenylsilane, and diethoxymethylvinylsilane. Examples of the M monomer that provides the structural unit (f) include hexamethyldisiloxane, hexaethyldisiloxane, hexapropyldisiloxane, 1,1,3,3-tetramethyldisiloxane, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, which provide two structural units (f) upon hydrolysis, as well as methoxydimethylsilane, ethoxydimethylsilane, methoxydimethylvinylsilane, ethoxydimethylvinylsilane, methoxytrimethylsilane, ethoxytrimethylsilane, methoxydimethylphenylsilane, ethoxydimethylphenylsilane, chlorodimethylsilane, chlorodimethylvinylsilane, chlorotrimethylsilane, dimethylsilanol, dimethylvinylsilanol, trimethylsilanol, triethylsilanol, tripropylsilanol, and tributylsilanol. Examples of the compound that reacts with the raw material monomer to give the structural unit (g) include water and alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 2-butanol.

[0054] The charging ratio of the raw material monomers Q monomer, T monomer, D monomer and M monomer may be appropriately set according to the desired values ​​of u to z in formula (1) in the present silsesquioxane derivative.

[0055] 2-2.Reaction solvent In the condensation step, an alcohol can be used as a reaction solvent. The alcohol according to the present disclosure is an alcohol in the narrow sense represented by the general formula R-OH, and is a compound having no functional groups other than an alcoholic hydroxyl group. The alcohol is not particularly limited, but specific examples thereof include methanol, ethanol, 1-propanol, 2-propanol, 2-butanol, 2-pentanol, 3-pentanol, 2-methyl-2-butanol, 3-methyl-2-butanol, cyclopentanol, 2-hexanol, 3-hexanol, 2-methyl-2-pentanol, 3-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-3-pentanol, 2-ethyl-2-butanol, 2,3-dimethyl-2-butanol, and cyclohexanol. Among these, secondary alcohols such as 2-propanol, 2-butanol, 2-pentanol, 3-pentanol, 3-methyl-2-butanol, cyclopentanol, 2-hexanol, 3-hexanol, 3-methyl-2-pentanol, and cyclohexanol are preferably used. In the condensation step, these alcohols can be used alone or in combination of two or more. More preferred alcohols are compounds that can dissolve water at the concentration required in the condensation step. Alcohols with such properties are compounds that have a water solubility of 10 g or more per 100 g of alcohol at 20°C.

[0056] The amount of alcohol used in the condensation step, including the amount added during the hydrolysis and polycondensation reaction, is 0.5% by mass or more based on the total amount of all reaction solvents, so that gelation of the silsesquioxane derivative produced can be suppressed. The amount used is preferably 1% by mass or more and 60% by mass or less, and more preferably 3% by mass or more and 40% by mass or less.

[0057] The reaction solvent used in the condensation step may be only an alcohol, or may be a mixed solvent with at least one auxiliary solvent. The auxiliary solvent may be either a polar solvent or a non-polar solvent, or a combination of both. Preferred polar solvents are secondary or tertiary alcohols having 3 or 7 to 10 carbon atoms, and diols having 2 to 20 carbon atoms.

[0058] Examples of non-polar solvents include, but are not limited to, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, chlorinated hydrocarbons, ethers, amides, ketones, esters, and cellosolves. Among these, aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons are preferred. Examples of such non-polar solvents include, but are not limited to, n-hexane, isohexane, cyclohexane, heptane, toluene, xylene, and methylene chloride, which are azeotropic with water, and the combined use of these compounds makes it possible to efficiently distill off water when removing the reaction solvent by distillation from the reaction mixture containing the silsesquioxane derivative after the condensation step. As a non-polar solvent, xylene, which is an aromatic hydrocarbon, is particularly preferred because of its relatively high boiling point.

[0059] 2-3. Water and catalyst used in hydrolysis reaction The hydrolysis and polycondensation reaction in the condensation step is carried out in the presence of water. The amount of water used to hydrolyze the hydrolyzable groups contained in the raw material monomers is preferably 0.5 to 5 times by mol, more preferably 1 to 2 times by mol, based on the substance amount (mol) of the hydrolyzable groups. The hydrolysis and polycondensation reaction of the raw material monomers may be carried out without a catalyst or with a catalyst. When a catalyst is used, an acid catalyst such as an inorganic acid, such as sulfuric acid, nitric acid, hydrochloric acid, or phosphoric acid, or an organic acid, such as formic acid, acetic acid, oxalic acid, or paratoluenesulfonic acid, is preferably used. The amount of the acid catalyst used is preferably an amount corresponding to 0.01 to 20 mol %, and more preferably an amount corresponding to 0.1 to 10 mol %, based on the total amount (mol) of silicon atoms contained in the raw material monomers.

[0060] 2-4. Other additives The completion of the hydrolysis / polycondensation reaction in the condensation step can be appropriately detected by the methods described in various publications, etc. In the condensation step for producing the silsesquioxane derivative according to the present disclosure, an auxiliary can be added to the reaction system. Examples of such agents include antifoaming agents that suppress foaming of the reaction liquid, scale control agents that prevent scale adhesion to the reaction vessel or stirring shaft, polymerization inhibitors, hydrosilylation reaction inhibitors, etc. The amount of these agents used is arbitrary, but is preferably about 1 to 100% by weight based on the concentration of the silsesquioxane derivative according to the present disclosure in the reaction mixture.

[0061] 2-5. Distillation of reaction solvents, etc. By providing a distillation step for distilling off the reaction solvent, by-products, residual monomers, water, catalyst, etc. contained in the reaction liquid obtained from the condensation step after the condensation step in the production of the silsesquioxane derivative according to the present disclosure, the stability of the produced silsesquioxane derivative according to the present disclosure can be improved. The distillation can be performed under normal pressure or reduced pressure, at room temperature or under heating, or under cooling.

[0062] 3. Hydrosilylation catalyst The photocurable composition of the present disclosure includes a hydrosilylation catalyst containing a transition metal, which allows the silsesquioxane derivative to be photocured. The transition metal contained in the hydrosilylation catalyst is not particularly limited, and examples thereof include simple substances, metal complexes, metal salts, and metal oxides of metals belonging to Groups 8 to 10, such as iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum. Among these, the hydrosilylation catalyst is preferably one containing one or more of the platinum group metals consisting of ruthenium, rhodium, palladium, osmium, iridium, and platinum. From the viewpoints of reactivity and availability, a catalyst containing platinum is more preferable, and a platinum complex is even more preferable. Platinum complexes include β-diketonatoplatinum complexes, (η-cyclopentadienyl)trialkylplatinum complexes, (η 4 The platinum complex is preferably at least one selected from the group consisting of (η-cyclopentadienyl)diaryl platinum complexes and dialkyl azodicarboxylate platinum complexes. Particularly preferred platinum complexes include β-diketonato platinum complexes represented by the following formula (2), (η-cyclopentadienyl)trialkyl platinum complexes represented by the following formula (3), and (η-cyclopentadienyl)trialkyl platinum complexes represented by the following formula (4). 4 and dialkyl azodicarboxylate platinum complexes containing a dialkyl azodicarboxylate represented by the following formula (5) as a ligand.

[0063] [ka]

[0064] [In formula (2), R 6 and R 7 are each independently at least one selected from the group consisting of a hydrogen atom, an alkyl group, and an aryl group, and may be the same or different from each other; R 8 , R 9 , R 10 and R 11 are each independently at least one selected from the group consisting of an alkyl group, an aryl group, and an alkoxy group, and may be the same or different.

[0065] [ka]

[0066] In formula (3), Cp is a cyclopentadienyl group η-bonded to a platinum atom, which may or may not be substituted with a substituent; R 12 , R 13 and R 14 each independently represents an aliphatic group having 1 to 18 carbon atoms σ-bonded to a platinum atom, and may be the same or different.

[0067] [ka]

[0068] [In formula (4), R 15 is a linear, branched or cyclic alkadiene group π-bonded to a platinum atom, each of which may or may not be substituted; R 17 and R 18 are each independently an aryl group σ-bonded to a platinum atom, which may or may not have a substituent and which may be the same or different from each other; R 16 and R 19 are each independently at least one selected from the group consisting of a hydrogen atom, an alkyl group, an alkoxy group, and a halogen atom, may be the same or different, may be substituted at any position of the aryl group, and may each be substituted with multiple substituents.

[0069] [ka]

[0070] [In formula (5), multiple R 20 each independently represents a hydrocarbon group having 1 to 6 carbon atoms, and may be the same or different. In addition, in formula (5), only the ligand is shown, and the platinum atom is omitted.

[0071] Specific examples of the β-diketonato platinum complexes represented by the formula (2) include bis(acetylacetonato)platinum(II). Specific examples of the (η-cyclopentadienyl)trialkylplatinum complexes represented by the formula (3) include trimethyl(methylcyclopentadienyl)platinum(IV) and (cyclopentadienyl)trimethylplatinum(IV). (η 4 Specific examples of the (η -1,5-cyclooctadiene) diaryl platinum complexes include 4 -1,5-cyclooctadiene)bis(4-methoxyphenyl)platinum(II) and the like. Specific examples of platinum complexes containing a dialkylazodicarboxylate represented by the formula (5) as a ligand include diethylazodicarboxylate platinum(II). Among these compounds, bis(acetylacetonato)platinum(II) and trimethyl(methylcyclopentadienyl)platinum(IV) are more preferred.

[0072] The transition metal content is not particularly limited, but is preferably 0.1 to 30,000 ppm by weight, more preferably 1.0 to 10,000 ppm by weight, and even more preferably 10 to 2,000 ppm by weight, relative to 100 parts by weight of the total amount of the silsesquioxane derivative according to the present disclosure.

[0073] 4. Photocurable composition The photocurable composition of the present disclosure (hereinafter also referred to as the "composition of the present disclosure") contains a silsesquioxane derivative according to the present disclosure and a hydrosilylation catalyst. The composition of the present disclosure has excellent flowability and, as described below, has excellent heat resistance and insulating properties when cured, making it a good insulating material for insulating elements that require heat resistance. In addition, the composition of the present disclosure can itself exhibit good curability and adhesive properties, and can be used as an adhesive composition or a binder composition. The composition of the present disclosure contains the silsesquioxane derivative and a hydrosilylation catalyst, and may contain various other components (hereinafter referred to as "other components") as necessary. As the other components, a heat resistance improver, a hydrosilylation reaction inhibitor, a solvent, and the like are preferable. The other ingredients will be described below.

[0074] 4-1.Heat resistance improver The compositions of the present disclosure may include a heat resistance enhancer. The heat resistance improver is not particularly limited, and known ones can be used. Examples of the heat resistance improver include organic carboxylates such as iron 2-ethylhexanoates such as iron tris(2-ethylhexanoate)(III), cerium 2-ethylhexanoates such as cerium tris(2-ethylhexanoate)(III), and zirconium 2-ethylhexanoates such as zirconium tetra(2-ethylhexanoate)(IV) and zirconium oxide bis(2-ethylhexanoate)(IV), and metal oxides such as iron oxide, cerium oxide, and zirconium oxide. The proportion of the heat resistance improver used is not particularly limited, but is, for example, 0 to 10,000 ppm by weight, preferably 1 to 1,000 ppm by weight, more preferably 5 to 500 ppm by weight, and even more preferably 10 to 300 ppm by weight, relative to 100 parts by weight of the total amount of the silsesquioxane derivative according to the present disclosure. The addition of a heat resistance improver can improve or suppress a decrease in the thermal weight loss temperature, suppress a decrease in the relative dielectric constant and insulating properties, suppress the occurrence of cracks, and suppress coloration during use and storage under heating and at room temperature.

[0075] 4-2. Hydrosilylation reaction inhibitors The compositions of the present disclosure may include a hydrosilylation reaction inhibitor. By doing so, the storage stability of the composition of the present disclosure can be improved. There is no particular limitation on the hydrosilylation reaction inhibitor, and examples thereof include compounds that can be coordinated to a hydrosilylation catalyst metal, such as vinyl siloxanes such as methylvinyltetrasiloxane, acetylene alcohols such as 2-methyl-3-butyn-2-ol, siloxane-modified acetylene alcohols, hyperoxides, and known hydrosilylation reaction inhibitors containing a nitrogen atom, a sulfur atom, or a phosphorus atom. Among these, siloxane compounds having a structure in which a group having a carbon-carbon triple bond is bonded to a silicon atom, as disclosed in JP 2010-143973 A, are preferred, in that they have an appropriate reaction inhibition effect, are low in volatility, and suppress odor and coloring. The proportion of the hydrosilylation reaction inhibitor used is not particularly limited, but is, for example, 0 to 5.0% by weight, preferably 0 to 2.0% by weight, and more preferably 0 to 1.0% by weight, relative to 100 parts by weight of the total amount of the silsesquioxane derivative according to the present disclosure.

[0076] 4-3.Solvent The composition of the present disclosure can be applied directly to the surface of a substrate if it is a liquid substance, but can also be diluted with a solvent as necessary. When using a solvent, it is preferable to use a solvent that dissolves the silsesquioxane derivative of the present disclosure, and examples of the solvent include various organic solvents such as aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, chlorinated hydrocarbon solvents, alcohol solvents, ether solvents, amide solvents, ketone solvents, ester solvents, and cellosolve solvents. When a solvent is used, it is preferable to volatilize the solvent contained in the applied film prior to curing the composition of the present disclosure. The solvent may be volatilized in the air or in an inert gas atmosphere such as nitrogen. Heating may be performed to volatilize the solvent, and the heating temperature in this case is preferably less than 100°C.

[0077] 4-4. Other ingredients not mentioned above The composition of the present disclosure may contain other components other than the above-mentioned components as necessary. Specifically, it may contain any other auxiliary agent such as surfactants, antistatic agents (e.g., conductive polymers), leveling agents, photosensitizers, UV absorbers, antioxidants, stabilizers, lubricants, pigments, dyes, plasticizers, suspending agents, nanoparticles, nanofibers, nanosheets, and fillers, etc. It may also contain silane-based reactive diluents such as tetraalkoxysilanes, trialkoxysilanes, dialkoxysilanes, monoalkoxysilanes, and disiloxanes. Furthermore, other photocurable compounds such as radically curable compounds and cationic curable compounds may also be contained, and a photopolymerization initiator therefor may also be contained.

[0078] 5.Cured product The cured product of the present disclosure is a cured product obtained by curing the above-mentioned composition of the present disclosure.

[0079] 5-1, Physical properties of cured product The cured product of the present disclosure has excellent heat resistance. Indicators of heat resistance are not particularly limited, but examples thereof include thermal weight loss temperature, dielectric constant, insulation, coloration, adhesiveness, tackiness, light transparency, and crack generation.

[0080] 5-1-1. Thermogravimetric reduction temperature The cured product of the present disclosure has excellent heat resistance and a high thermal weight loss temperature. The thermal weight loss temperature can be determined by thermogravimetric differential thermal analysis (hereinafter referred to as TG / DTA). There is no particular limitation on the measurement atmosphere, and the measurement can be performed in air or in an inert gas atmosphere such as nitrogen. The measurement atmosphere is appropriately selected in consideration of the environment in which the cured product of the present disclosure is used, but it is preferable to perform the measurement in air. There is no particular limitation on the heating rate during measurement, and it can be, for example, 5, 10, or 20°C / min. Considering that it can be measured in a short time, 20°C / min is preferable. There is no particular limitation on the index of the weight loss temperature, and it can be, for example, the temperature at the time when a certain percentage of the original weight is reduced, such as the weight loss start temperature and the 1, 5, or 10% weight loss temperature. It can also be expressed as the weight loss rate at a certain temperature, such as the weight loss rate at 400°C.

[0081] The 5% weight loss temperature of the cured product of the present disclosure, measured in air at 20°C / min, is, for example, 300°C or higher, preferably 370°C or higher, more preferably 400°C or higher, and particularly preferably 500°C or higher.

[0082] 5-1-2. Dielectric constant The cured product of the present disclosure has a low dielectric constant and is excellent in insulation over a wide frequency band. The dielectric constant of the cured product of the present disclosure is not particularly limited, but is, for example, 4.0 or less, preferably 3.6 or less, and more preferably 3.5 or less. The frequency band in which the dielectric constant is used is not particularly limited, but is, for example, 1 kHz to 100 GHz, preferably 1 kHz to 1 GHz, and more preferably 1 kHz to 10 MHz. For example, the cured product of the present disclosure has a dielectric constant of 4.0 or less at 1 MHz. When comparing the values ​​of the dielectric constant between cured products, the measurement frequency is not particularly limited, but for example, the dielectric constant can be measured at 1 kHz, 10 kHz, 100 kHz, 1 MHz, 10 MHz, 1 GHz, etc., to compare the insulating properties of the cured products. In addition, the insulating properties can be evaluated by showing that the dielectric constant is equal to or lower than a certain value over a certain frequency band. The frequency band is not particularly limited, but for example, the dielectric constant can be shown from 1 kHz to 10 MHz. In addition, the relative dielectric constant in this disclosure means a value measured at room temperature (23° C.±2° C.).

[0083] As described above, the cured product of the present disclosure has a low dielectric constant and excellent insulating properties over a wide frequency band. Therefore, the cured product of the present disclosure can be an insulating film. The cured product (insulating film) of the present disclosure is obtained by curing the composition of the present disclosure, and the curing means is not particularly limited, but for example, it may be cured by irradiation with ultraviolet light. Details of the curing means will be described later in "Method for producing the cured product".

[0084] 6. Manufacturing method of the cured product The method for producing the cured product (insulating film) of the present disclosure includes a step of curing the composition of the present disclosure by irradiating it with ultraviolet light. The obtained cured product (insulating film) may be the cured product (insulating film) of the present disclosure described above. When the composition of the present disclosure is cured, for example, the composition of the present disclosure is applied to a suitable substrate, and then irradiated with light such as ultraviolet light to promote the hydrosilylation reaction and cure the composition. The composition of the present disclosure may or may not contain a solvent. When the composition contains a solvent, it is preferable to remove the solvent before photocuring or the like, as described above.

[0085] 6-1. Application method When the composition of the present disclosure is used by applying it to a substrate, the application method is not particularly limited, and for example, a typical application method such as a casting method, a spin coating method, a bar coating method, a dip coating method, a spray coating method, a roll coating method, a flow coating method, or a gravure coating method can be used. There is no particular limitation on the thickness to which the composition of the present disclosure is applied, and it may be appropriately set depending on the purpose. There are no particular limitations on the substrate to which the composition of the present disclosure can be applied, and the composition can be applied to a variety of materials, including wood, metal, inorganic materials, plastics, paper, fibers, and fabrics. Examples of metals include copper, silver, iron, aluminum, silicon, silicon steel, and stainless steel. Examples of inorganic materials include metal oxides such as aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, zinc oxide, indium tin oxide, and gallium oxide, metal nitrides such as aluminum nitride, gallium nitride, and silicon nitride, ceramics such as silicon carbide and boron nitride, mortar, concrete, and glass. Specific examples of plastics include acrylic resins such as polymethyl methacrylate, polyester resins such as polyethylene terephthalate, polyvinyl chloride resins, polycarbonate resins, epoxy resins, polyamide resins such as nylon and aramid, polyimide resins, polyamideimide resins, fluororesins such as tetrafluoroethylene resins, polyolefin resins such as cross-linked polyethylene resins, composite resins such as polychloroprene, polyphenylene sulfide, polysulfone, polyethersulfone, polyetheretherketone, polyurethane resins, and glass epoxy resins. Examples of fibers include natural fibers, regenerated fibers, semi-synthetic fibers, metal fibers, glass fibers, carbon fibers, ceramic fibers, and known chemical fibers. The fabric may be woven or nonwoven and may be made, for example, using the fibers described above. These materials may be used alone, or two or more of them may be used in combination, mixture, or composite. The shape of the substrate is not particularly limited, and examples thereof include a plate, a sheet, a film, a rod, a sphere, a fiber, a powder, and a structure having a complex shape.

[0086] 6-2.Curing method In order to cure the composition of the present disclosure, active energy rays can be irradiated. Examples of active energy rays include electron beams, and light such as ultraviolet rays, visible light, and X-rays. Light is preferred, and ultraviolet rays are more preferred because inexpensive equipment can be used. Examples of ultraviolet irradiation devices include high-pressure mercury lamps, metal halide lamps, UV electrodeless lamps, and LEDs. The irradiation energy should be set appropriately depending on the type of active energy rays and the composition of the formulation. For example, when using a high-pressure mercury lamp, the irradiation energy in the UV-A region (315 nm to 400 nm) is 0.1 to 30 J / cm. 2 is preferable, and 0.5 to 20 J / cm 2 More preferably, 1.0 to 15 J / cm 2 is more preferred.

[0087] Furthermore, before and / or after the photocuring, heat curing can be appropriately combined. For example, a two-stage curing process can be performed in which a substrate having a portion that is shaded when irradiated with light is impregnated with the composition of the present disclosure, and then the substrate is irradiated with light to first cure the composition of the present disclosure in the portion exposed to light, and then heat is applied to cure the composition of the present disclosure in the portion not exposed to light. There are no particular limitations on such substrates, and examples of the substrates include substrates having complex shapes such as fabric, fiber, powder, porous, and uneven shapes, and the substrates may have a shape in which two or more of these shapes are combined.

[0088] 7.Applications The cured product of the composition of the present disclosure has excellent heat resistance, oxidation resistance, weather resistance, hardness, transparency, and flexibility, and materials having a cured film of the composition of the present disclosure can be used for various applications by taking advantage of these properties. For example, it can be used in various industrial product fields such as electric and electronic fields, etc. Particularly, specific examples of preferred applications include lighting devices such as LED lighting and organic EL lighting, semiconductor modules, electronic circuit boards such as printed wiring boards and flexible wiring boards, electric rotating devices such as small motors and in-vehicle motors, power supply devices such as transformers, electricity storage devices such as lithium batteries, and power generation devices such as solar panels. For example, a composite material having a cured product of the composition of the present disclosure and the above-mentioned substrate is useful as a heat-resistant insulating member. As the substrate, the substrates described in the above section "6. Method for producing the cured product" can be used. EXAMPLES

[0089] Next, the present disclosure will be specifically described based on examples and comparative examples, but the present disclosure is not limited to the following examples. The weight average molecular weight (Mw) was determined by gel permeation chromatography (hereinafter referred to as "GPC") using a combination of GPC columns "TSK gel G4000HX" and "TSK gel G2000HX" (model names, manufactured by Tosoh Corporation) in a toluene solvent at 40°C, and the molecular weight was calculated from the retention time using standard polystyrene. The molar ratio of each of the structural units of the obtained silsesquioxane derivative was determined by dissolving the sample in deuterated chloroform and 1 H-NMR analysis will be performed, and further analysis will be performed if necessary. 29 The ratio was calculated by Si-NMR analysis. The alkoxysilane monomer reacted quantitatively and was introduced into the silsesquioxane derivative, but the M unit derived from the disiloxane monomer was not quantitatively introduced depending on the composition of the silsesquioxane derivative.

[0090] [Synthesis of silsesquioxane derivatives] <Synthesis Example 1> Trimethoxyvinylsilane (7.4 g, 50 mmol), methyltriethoxysilane (26.7 g, 150 mmol), dimethoxydimethylsilane (3.0 g, 25 mmol), 1,1,3,3-tetramethyldisiloxane (3.4 g, 25 mmol), xylene (15 g), and 2-propanol (15 g) were weighed out and placed in a 200 mL four-neck round-bottom flask equipped with a thermometer, a dropping funnel, and a stirring blade, and the mixture was thoroughly stirred in a water bath at about 20° C. A solution that had been separately prepared by mixing 1 mol / L hydrochloric acid aqueous solution (0.45 g, 4.4 mmol), pure water (11.4 g), and 2-propanol (4.5 g) was dropped into the flask from the dropping funnel over a period of about 1 hour, and the mixture was further stirred overnight at room temperature. The solvent and the like were removed from the resulting solution at reduced pressure at 60° C., yielding 19 g of silsesquioxane derivative 1 as a colorless, transparent liquid.

[0091] <Synthesis Example 2> Silsesquioxane derivative 2 was obtained as a colorless, transparent liquid by carrying out the same procedure as for silsesquioxane derivative 1, except that allyltrimethoxysilane (50 mmol), phenyltrimethoxysilane (150 mmol), dimethoxydiphenylsilane (25 mmol), and 1,1,3,3-tetramethyldisiloxane (25 mmol) were used as the raw silane monomers.

[0092] <Synthesis Example 3> Silsesquioxane derivative 3 was obtained as a colorless, transparent liquid by carrying out the same procedure as for silsesquioxane derivative 1, except that triethoxysilane (150 mmol), trimethoxyvinylsilane (50 mmol), dimethoxydimethylsilane (25 mmol), and 1,1,3,3-tetramethyldisiloxane (50 mmol) were used as the raw silane monomers.

[0093] <Synthesis Example 4> Silsesquioxane derivative 4 was obtained as a colorless, transparent liquid by carrying out the same procedure as for silsesquioxane derivative 1, except that triethoxysilane (150 mmol), trimethoxyvinylsilane (50 mmol), and 1,1,3,3-tetramethyldisiloxane (50 mmol) were used as the raw silane monomers.

[0094] <Synthesis Example 5> Silsesquioxane derivative 5 was obtained as a colorless, transparent liquid by carrying out the same procedure as for silsesquioxane derivative 1, except that triethoxysilane (150 mmol), trimethoxyvinylsilane (25 mmol), (p-styryl)trimethoxysilane (25 mmol), and 1,1,3,3-tetramethyldisiloxane (50 mmol) were used as the raw silane monomers.

[0095] <Synthesis Example 6> Silsesquioxane derivative 6 was obtained as a colorless, transparent liquid by carrying out the same procedure as for silsesquioxane derivative 1, except that triethoxysilane (200 mmol), dimethoxymethylsilane (75 mmol), and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane (50 mmol) were used as the raw silane monomers.

[0096] <Synthesis Example 7> Silsesquioxane derivative 7 was obtained as a colorless, transparent liquid by carrying out the same procedure as for silsesquioxane derivative 1, except that triethoxysilane (100 mmol), trimethoxyvinylsilane (100 mmol), and dimethoxymethylsilane (100 mmol) were used as the raw silane monomers.

[0097] <Synthesis Example 8> Silsesquioxane derivative 8 was obtained as a colorless, transparent liquid by carrying out the same procedure as for silsesquioxane derivative 1, except that triethoxysilane (150 mmol) and trimethoxyvinylsilane (120 mmol) were used as raw silane monomers.

[0098] <Synthesis Example 9> Silsesquioxane derivative 9 was obtained as a colorless, transparent liquid by carrying out the same procedure as for silsesquioxane derivative 1, except that triethoxysilane (150 mmol), trimethoxyvinylsilane (50 mmol), phenyldimethoxysilane (25 mmol), and 1,1,3,3-tetramethyldisiloxane (50 mmol) were used as the raw silane monomers.

[0099] <Synthesis Example 10> Silsesquioxane derivative 10 was obtained as a colorless, transparent liquid by carrying out the same procedure as for silsesquioxane derivative 1, except that tetramethoxysilane (100 mmol), dimethoxydimethylsilane (100 mmol), 1,1,3,3-tetramethyldisiloxane (12.5 mmol), and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane (12.5 mmol) were used as the raw silane monomers.

[0100] <Synthesis Example 11> Silsesquioxane derivative 11 was obtained as a colorless semi-solid by carrying out the same operation as for silsesquioxane derivative 1, except that tetramethoxysilane (90 mmol), triethoxysilane (36 mmol), trimethoxyvinylsilane (30 mmol), dimethoxydimethylsilane (36 mmol), 1,1,3,3-tetramethyldisiloxane (7.5 mmol) and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane (22.5 mmol) were used as raw silane monomers.

[0101] Tables 1 and 2 show the compositions, Mw, and molar ratios of each of the introduced structural units in Synthesis Examples 1 to 11.

[0102] [Table 1]

[0103] [Table 2]

[0104] <Reference example 1> [Synthesis of 3-acryloyloxypropylsilsesquioxane] A colorless, transparent liquid, 3-acryloyloxypropylsilsesquioxane, was obtained by carrying out the same procedure as for silsesquioxane derivative 1, except that (3-acryloyloxypropyl)trimethoxysilane was used as the raw silane monomer and only 2-propanol was used as the reaction solvent. The Mw was 2370. <Reference example 2> Toagosei AC-SQ SI-20 (a composite derivative of 3-acryloyloxypropylsilsesquioxane and silicone) was used as is.

[0105] <Example 1> (1) Preparation of photocurable composition 10 g of the silsesquioxane derivative obtained in Synthesis Example 1 and 10 mg of bis(acetylacetonato)platinum(II) (hereinafter referred to as Pt(acac)2) were weighed out and dissolved by stirring in a planetary centrifugal mixer. (2) Confirmation of photohydrosilylation curing The photocurable composition (1) described above was applied to a copper plate using a bar coater to form a coating of about 100 μm in thickness. Then, ultraviolet light was irradiated under the following conditions, and it was confirmed that the surface had lost its tackiness. Furthermore, the coating formed on the copper plate was peeled off, and FT-IR (Fourier transform infrared spectroscopy) analysis (Spectrum 100, manufactured by Perkin Elmer) confirmed that the hydrosilyl and vinyl groups had decreased, indicating that the hydrosilylation reaction had progressed. [Ultraviolet irradiation conditions] Lamp: 80W / cm high pressure mercury lamp Lamp height: 10cm Conveyor speed: 4.5m / min Accumulated light output per pass: 990 mJ / cm 2 Atmosphere: Air Number of passes: 10

[0106] <Example 2> [Preparation of photocurable composition and confirmation of photocurability] A photocurable composition was prepared in the same manner as in Example 1(1) using the silsesquioxane derivative 2 obtained in Synthesis Example 2. The photocurable composition was subjected to photocuring in the same manner as in Example 1(2), and it was confirmed that a photohydrosilylation reaction proceeded to give a cured product.

[0107] <Examples 3 to 11> [Preparation of photocurable composition and confirmation of photocurability] Photocurable compositions were prepared in the same manner as in Example 1(1) using the silsesquioxane derivatives 3 to 11 obtained in Synthesis Examples 3 to 11. They were subjected to photocuring in the same manner as in Example 1(2) except that the following ultraviolet irradiation conditions were used. It was confirmed that the photohydrosilylation reaction proceeded in all cases to give a cured product. [Ultraviolet irradiation conditions] Lamp: 80W / cm high pressure mercury lamp Lamp height: 10cm Conveyor speed: 10m / min Accumulated light output per pass: 210 mJ / cm 2 Atmosphere: Air Number of passes: 30

[0108] <Example 12> Heat resistance evaluation of cured product A photohydrosilylation cured product was produced in the same manner as in Example 1(2) using the silsesquioxane derivative 1 obtained in Synthesis Example 1 and the photocurable composition prepared in Example 1(1), except that the substrate in Example 1(2) was replaced with a PET film. The resulting cured product was peeled off from the PET film and subjected to thermogravimetric differential thermal analysis (hereinafter referred to as TG / DTA) (TG / DTA6300 manufactured by Seiko Instruments Inc., in air, at a heating rate of 20°C / min) to determine the 5% weight loss temperature (hereinafter referred to as T d5 The temperature was calculated to be 396°C.

[0109] <Examples 13 to 16> [Evaluation of heat resistance of cured product] The silsesquioxane derivatives 3, 4, 7 and 10 obtained in Synthesis Examples 3, 4, 7 and 10 were used to prepare the photocurable compositions in Examples 3, 4, 7 and 10, and the TG / DTA of the cured products was measured in the same manner as in Example 12. d5 asked for.

[0110] T obtained in Examples 12 to 16 d5 are summarized in Table 3.

[0111] [Table 3]

[0112] <Example 17> Measurement of the dielectric constant of the cured material Using the silsesquioxane derivative 1 obtained in Synthesis Example 1, the photocurable composition prepared in Example 1(1) was poured into a mold made by cutting a hole measuring 40 mm × 40 mm in a 1 mm thick silicone rubber sheet, and the mold was sandwiched between a PET film and a white glass plate, and a photohydrosilylation cured product was produced under the same UV irradiation conditions as in Example 1(2). The obtained cured product was subjected to dielectric constant measurement (Agilent Technologies Impedance Analyzer 4294A) at room temperature (23°C), and the dielectric constant at 1 MHz was found to be 3.38. The dielectric constant at 1 MHz and the dielectric constant at other frequency bands are shown in Table 4.

[0113] <Example 18> Measurement of the dielectric constant of the cured material The photocurable composition prepared in Example 4 was used to measure the dielectric constant in the same manner as in Example 17, using silsesquioxane 4 obtained in Synthesis Example 4. The dielectric constant at 1 MHz was 3.28. Table 4 shows the dielectric constant at 1 MHz and the dielectric constants in other frequency bands.

[0114] <Comparative Example 1> 0.3 g of 2-hydroxy-2-methylpropiophenone (Tokyo Chemical Industry Co., Ltd.) was added to 10 g of 3-acryloyloxypropylsilsesquioxane obtained in Reference Example 1, and the mixture was stirred and dissolved to prepare a photocurable composition. This was applied to a PET film with a bar coater to form a coating film with a thickness of about 10 μm. Then, ultraviolet irradiation was performed under the following conditions to produce a cured product. [Ultraviolet irradiation conditions] Lamp: 80W / cm high pressure mercury lamp Lamp height: 10cm Conveyor speed: 10m / min Irradiation Accumulated light output per pass: 210 mJ / cm 2 Atmosphere: Air Number of passes: 30 T was determined in the same manner as in Example 12. d5 (in air) was 360°C. The relative dielectric constant at 1 MHz was found to be 4.24 in the same manner as in Example 17. The relative dielectric constant at 1 MHz and the relative dielectric constants in other frequency bands are shown in Table 4.

[0115] <Comparative Example 2> A cured product was prepared in the same manner as in Comparative Example 1, except that AC-SQ SI-20 of Reference Example 2 was used. d5 The relative dielectric constant was measured (in air). d5 (In air) was 340°C, and the relative dielectric constant at 1MHz was 4.31. The relative dielectric constant at 1MHz and the relative dielectric constants in other frequency bands are shown in Table 4.

[0116] The photohydrosilylation-curable composition of the present disclosure has good photocurability and is applicable to a wider range of substrates than known thermal hydrosilylation-curable compositions, enabling use in a variety of applications. In addition, the T d5 is extremely high as compared with the cured products of photoradical curable compositions (Comparative Examples 1 and 2), which are typical examples of conventional photocurable silsesquioxane derivatives, and thus has excellent heat resistance. Furthermore, the photohydrosilylation-cured product of the present disclosure has a dielectric constant that is very low compared to the cured product of the photoradical curable composition (Comparative Examples 1 and 2), and has excellent insulating properties at all frequencies measured. In the wide frequency range of 1 kHz to 10 MHz measured, the photohydrosilylation-cured product of the present disclosure has a dielectric constant of 3.5 or less, and has high heat resistance and excellent insulating properties.

[0117] [Table 4] [Industrial Applicability]

[0118] The photocurable composition of the present disclosure is useful for forming a heat-resistant film, and is a liquid composition that can be easily applied and filled into any shape. It can be cured at room temperature and can form a film having good properties such as water resistance, chemical resistance, stability, electrical insulation, and mechanical strength such as scratch resistance. Therefore, it can be used as a film or layer of articles or parts in a wide range of fields including the electronics field, the optical functional material field, the mobility field, the aerospace field, and the building material field. It can be used to form passivation films, resist films, interlayer insulating films, and various protective films in semiconductors, etc. The photocurable composition of the present disclosure and its cured product are useful in various fields where both high heat resistance and insulation properties are increasingly required in the future.

[0119] The disclosure of Japanese Patent Application No. 2020-106880, filed on June 22, 2020, is incorporated herein by reference in its entirety. All publications, patent applications, and standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A photocurable composition comprising a silsesquioxane derivative represented by the following formula (1) and a hydrosilylation catalyst containing a transition metal: 【Chemistry 1】 [In formula (1), R １ is an organic group having 2 to 12 carbon atoms and a hydrosilylation-reactive carbon-carbon unsaturated bond, R ２ is at least one selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms, Multiple R's ３ and R ４ each independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, and an organic group having 2 to 12 carbon atoms and a hydrosilylation reactive carbon-carbon unsaturated bond, Multiple R's ３ may be the same or different, Multiple R's ４ may be the same or different, u, v, w and x each independently represent 0 or a positive number, at least one of which is a positive number; Each of y and z is independently 0 or a positive number; 0≦y / (u+v+w+x)≦2.0, 0≦z / (u+v+w+x)≦2.0, However, when v = 0 and w is a positive number, there are multiple R ３ and R ４ At least one of R is a hydrogen atom, and when w=0 and v is a positive number, ３ and R ４ at least one of the R 3 s and R 4 s is an organic group having 2 to 12 carbon atoms and a carbon-carbon unsaturated bond capable of hydrosilylation, and when v = w = 0, at least one of the multiple R 3 s and R 4 s is a hydrogen atom, and at least one of the multiple R 3 s and R 4 s is an organic group having 2 to 12 carbon atoms and a carbon-carbon unsaturated bond capable of hydrosilylation.

2. 2. The photocurable composition according to claim 1, wherein the ratio of the number of hydrogen atoms bonded to silicon atoms to one organic group having a hydrosilylation reactive carbon-carbon unsaturated bond present in the silsesquioxane derivative is 0.5 to 5.

0.

3. 3. The photocurable composition according to claim 1, wherein the content of the transition metal is 0.1 to 30,000 ppm by weight based on 100 parts by weight of the silsesquioxane derivative.

4. The photocurable composition according to any one of claims 1 to 3, wherein the transition metal is a platinum group metal.

5. The hydrosilylation catalyst containing a transition metal is selected from the group consisting of β-diketonato platinum complexes, (η-cyclopentadienyl)trialkyl platinum complexes, (η ４ 5. The photocurable composition according to claim 1, wherein the platinum complex is at least one selected from the group consisting of platinum complexes having 1,5-cyclooctadiene diaryl groups and platinum complexes having dialkylazodicarboxylate groups.

6. The photocurable composition according to any one of claims 1 to 5, further comprising a heat resistance improver.

7. A cured product obtained by curing the photocurable composition according to any one of claims 1 to 6.

8. The cured product according to claim 7, having a dielectric constant of 4.0 or less at 1 MHz.

9. 9. The cured product according to claim 7, which has a 5% weight loss temperature in air of 300°C or higher in thermogravimetry.

10. The cured product according to any one of claims 7 to 9, which is an insulating film.

11. A method for producing a cured product, comprising a step of curing the photocurable composition according to any one of claims 1 to 6 by irradiating it with ultraviolet light.

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