JP6848825B2 - Photocurable composition and its cured product - Google Patents

Description

The present invention relates to a photocurable composition and a cured product thereof.

Polymer materials are generally characterized by excellent insulation, flexibility, and light weight, and are used in electrical and electronic equipment applications such as film capacitors, gate insulating films for field effect transistors, and resin antennas. It is used as a dielectric. Further, the transparent resin that transmits light is a useful material that is widely used in optical devices such as lenses and optical waveguides, and display devices such as displays.

Film capacitors are required to have a larger capacity and smaller size, but it is known that the capacity of a film capacitor is proportional to the relative permittivity of the film used and inversely proportional to the film thickness. Therefore, when the film thickness is the same, the higher the relative permittivity of the film, the larger the capacitance of the capacitor, which is preferable because a film capacitor having a high capacitance can be obtained. Since polymer materials such as polypropylene, polyester, and polyphenylene sulfide used for film capacitors have a low dielectric constant by themselves, for example, Patent Document 1 describes a polymer obtained by adding dielectric ceramics such as strontium titanate to polyphenylene sulfide. The composition is disclosed and states that it can be used in capacitors and antennas.

Regarding the material used for the resin antenna, Patent Document 2 discloses a dielectric elastomer laminate in which dielectric ceramics are added to an elastomer which is an intermediate layer to increase the relative permittivity, and the antenna is made higher in frequency and smaller in size. It is stated that it contributes to. Further, even when a synthetic resin is used for the insulating film of the field effect transistor, the resin having a higher relative permittivity is preferable because the transistor capacity increases.

An actuator, which is a device that converts a certain energy into mechanical energy when it is input, is a kind of transducer. There are several types of actuators, but actuators that use dielectric elastomer, which is a polymer material, can convert electrical energy into mechanical energy, and because they are flexible thin films, they are diverse, such as micropumps and speakers. Application to applications is being studied (Patent Document 3). On the contrary, it is known that a dielectric elastomer can also be used for a transducer that converts mechanical energy into electrical energy (Patent Document 4). Since the amount of displacement when a constant voltage is applied to the dielectric elastomer sandwiched between the electrodes is proportional to the relative permittivity of the elastomer, it is desirable to increase the relative permittivity in order to increase the energy conversion efficiency. For example, Patent Document 5 discloses a dielectric elastomer in which dielectric ceramic particles having a relative permittivity of 1,000 or more are dispersed in crosslinked rubber.

Special Table 2000-501549 Japanese Unexamined Patent Publication No. 2006-290939 Special Table 2001-524278 Special Table 2003-505865 Japanese Unexamined Patent Publication No. 2007-153961 Special Table 2010-505995

Resins with a high relative permittivity are required for all of the above-mentioned applications. When a dielectric ceramic such as strontium titanate is blended with a polymer material as in the technique of Patent Document 2, the relative permittivity is improved, but it is necessary to contain a large amount in order to obtain a sufficient effect, and as a result, molding is performed. It is not preferable because the property deteriorates and the material becomes hard. In addition, in order to mix an inorganic material such as dielectric ceramics with a polymer material and disperse it uniformly, special treatment such as appropriate surface treatment with a silane coupling agent is required, and curability is required. When the resin and the dielectric ceramic are mixed, there is a problem that it is difficult to stabilize the composition because the difference in specific gravity between the prepolymer, the monomer and the like and the dielectric ceramic is large. Further, the dielectric ceramic has a large specific gravity, and the light weight characteristic of the polymer material may be impaired.

On the other hand, Patent Document 6 proposes the use of a fluorine-based polymer such as vinylidene fluoride having a high relative permittivity, but a fluorine-based polymer having a high fluorine content is expensive and highly versatile. I can't say.

Therefore, there is a demand for a polymer material having an improved relative permittivity without significantly affecting the lightness, moldability, and mechanical properties that are the original characteristics of the polymer material.

The present invention provides a photocurable composition and a cured product thereof, which meet the above requirements, have good moldability, are lightweight, have a high relative permittivity, and can form a polymer material having a transparent appearance. The purpose is to do.

As a result of diligent studies to achieve the above object, the present inventors have formed a photocurable composition containing silsesquioxane having a fluorine-substituted aryl group, a specific polymerizable monomer, and a photopolymerization initiator. We have found that a polymer material having good properties, having a high relative permittivity, and being transparent and lightweight can be obtained by curing the polymer material, and have completed the present invention.

（式中、Ａは同一でも異なっていてもよく、炭素数６〜２５のアリール基を表し、前記アリール基の水素原子のうち少なくとも１個がフッ素原子で置換されている。Ｐは同一でも異なっていてもよく、炭素数２〜１０のエチレン性不飽和基を表す。Ｒ¹は同一でも異なっていてもよく、炭素数１〜１０の二価炭化水素基を表す。Ｒ²は同一でも異なっていてもよく、炭素数１〜１０の二価炭化水素基または単結合を表す。ただし、Ｐ−Ｒ²−で表される基とケイ素原子との間の結合は、実質的に加水分解性を有しない。ｍは４〜４００の整数、ｎは１〜１００の整数を表し、０．１≦［ｍ／（ｍ＋ｎ）］＜１の条件を満たす。）
で表されるフッ素置換アリール基を有するシルセスキオキサン、
（ｂ）一種類以上のエチレン性不飽和一官能モノマー、
（ｃ）一種類以上のエチレン性不飽和多官能モノマーおよび
（ｄ）光重合開始剤
を必須成分として含むことを特徴とする光硬化性組成物。
２． 上記式（１）において、Ａがフェニル基又はアルキル置換フェニル基であって、前記フェニル基又はアルキル基の水素原子のうち少なくとも１個がフッ素原子で置換された基である１に記載の光硬化性組成物。
３． 上記式（１）において、Ｐがビニル基、アリル基、ブテニル基、メタリル基、アクリロイルオキシ基およびメタクリロイルオキシ基から選ばれる基である１または２記載の光硬化性組成物。
４． （ｂ）成分が、α，β−不飽和カルボン酸エステルである１〜３のいずれかに記載の光硬化性組成物。
５． （ｃ）成分が、多価アルコールのα，β−不飽和カルボン酸エステルである１〜４のいずれかに記載の光硬化性組成物。
６． １〜５のいずれかに記載の光硬化性組成物の硬化物。 That is, the present invention provides the following photocurable compositions and cured products thereof.
1. 1. (A) The following general formula (1)

(In the formula, A may be the same or different and represents an aryl group having 6 to 25 carbon atoms, and at least one of the hydrogen atoms of the aryl group is substituted with a fluorine atom. P is the same or different. It may be, and represents an ethylenically unsaturated group having 2 to 10 carbon atoms. R ¹ may be the same or different, and represents a divalent hydrocarbon group having 1 to 10 carbon atoms. R ² is the same or different. It may be a divalent hydrocarbon group having 1 to 10 carbon atoms or a single bond. However, ^{the bond between the group represented by PR 2} − and the silicon atom is substantially hydrolyzable. M represents an integer of 4 to 400, n represents an integer of 1 to 100, and the condition of 0.1 ≦ [m / (m + n)] <1 is satisfied.)
Silsesquioxane having a fluorine-substituted aryl group represented by
(B) One or more kinds of ethylenically unsaturated monofunctional monomers,
A photocurable composition comprising (c) one or more kinds of ethylenically unsaturated polyfunctional monomers and (d) a photopolymerization initiator as essential components.
2. The photocuring according to 1 in the above formula (1), wherein A is a phenyl group or an alkyl-substituted phenyl group, and at least one of the hydrogen atoms of the phenyl group or the alkyl group is a group substituted with a fluorine atom. Sex composition.
3. 3. The photocurable composition according to 1 or 2, wherein in the above formula (1), P is a group selected from a vinyl group, an allyl group, a butenyl group, a metallicyl group, an acryloyloxy group and a methacryloyloxy group.
4. The photocurable composition according to any one of 1 to 3, wherein the component (b) is an α, β-unsaturated carboxylic acid ester.
5. The photocurable composition according to any one of 1 to 4, wherein the component (c) is an α, β-unsaturated carboxylic acid ester of a polyhydric alcohol.
6. A cured product of the photocurable composition according to any one of 1 to 5.

The photocurable composition of the present invention can be obtained by a simple method and has good moldability. Further, the polymer material, which is a cured product obtained by curing the photocurable composition of the present invention, has a high relative permittivity and is transparent because the constituent components are uniformly mixed inside the material without agglomeration. is there. Furthermore, it is lightweight because it does not contain ceramics with a high specific gravity.

It is a Fourier transform infrared absorption spectrum of silsesquioxane obtained in Synthesis Example 1. It is a Fourier transform infrared absorption spectrum of silsesquioxane obtained in Synthesis Example 2. It is a Fourier transform infrared absorption spectrum of silsesquioxane obtained in Synthesis Example 3. It is a Fourier transform infrared absorption spectrum of silsesquioxane obtained in Synthesis Example 4.

Hereinafter, the photocurable composition of the present invention and the cured product thereof will be specifically described.
<Photocurable composition>
(A) Fluoresquioxane having a fluorine-substituted aryl group The photocurable composition of the present invention contains silsesquioxane having a fluorine-substituted aryl group represented by the following general formula (1) as an essential component.

In the above general formula (1), A may be the same or different, and represents an aryl group having 6 to 25 carbon atoms, preferably 6 to 10 carbon atoms, and at least one of the hydrogen atoms of the aryl group is a fluorine atom. It has been replaced.

Here, examples of the aryl group having 6 to 25 carbon atoms, preferably 6 to 10 carbon atoms include a phenyl group and an alkyl-substituted phenyl group. Examples of the alkyl substituent when A has an alkyl substituent include an alkyl group having 1 to 3 carbon atoms such as a methyl group, an ethyl group, an n-propyl group and an isopropyl group, and a methyl group is particularly preferable. The number of alkyl substituents is preferably 1 to 5, more preferably 1 to 3.

The fluorine atom may be directly bonded to the phenyl group constituting A, or may be bonded to the alkyl group when it has an alkyl group. The number of fluorine atoms contained in A is preferably 1 to 10, more preferably 2 to 6, and even more preferably 2 to 5.

Specific examples of A include a pentafluorophenyl group; a tetrafluoroaryl group such as a 2,3,4,5-tetrafluorophenyl group and a 2,3,5,6-tetrafluorophenyl group; 2,3,5- Trifluoroaryl groups such as trifluorophenyl group, 2,4,5-trifluorophenyl group, 3,4,5-trifluorophenyl group, 2,4,6-trifluorophenyl group; 2,4-difluorophenyl Difluoroaryl groups such as groups, 3,4-difluorophenyl groups and 3,5-difluorophenyl groups; monofluoroaryl groups such as 2-fluorophenyl groups, 3-fluorophenyl groups and 4-fluorophenyl groups; 4-tri Examples thereof include fluoroalkylaryl groups such as fluoromethylphenyl group, 3-trifluoromethylphenyl group and 3,5-bis (trifluoromethyl) phenyl group.

In the above general formula (1), R ¹ may be the same or different, and represents a divalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms. Specific examples of R ¹ include a methylene group, a 1,2-ethanediyl group, a 1,1-ethanediyl group, a 1,2-ethendyl group, a 1,1-ethendyl group, a 1,3-propanediyl group, 1,2. -Propanediyl group, 2-methyl-1,3-propanediyl group, 1,3-butanediyl group, 1,4-butanediyl group, 1,5-pentanediyl group, 1,6-hexanediyl group, 1,4- Cyclohexanediyl group, 1,7-heptandyl group, 1,8-octanediyl group, 1,9-nonandyl group, 1,10-decandyl group, 1,3-cyclohexanediyl group, 1,4-cyclohexanediyl group, etc. Linear, branched or cyclic aliphatic divalent hydrocarbon groups; 1,3-benzenediyl group, 1,4-benzenediyl group, 2-methyl-1,4-benzenediyl group, 3-methyl- 1,4-benzenediyl group, 2,5-dimethyl-1,4-benzenediyl group, 1,4-naphthalenedyl group, 2,6-naphthalenedyl group, 2,7-naphthalenedyl group, 4-ethylbenzene- Examples thereof include aromatic divalent hydrocarbon groups such as 1,2-diyl group and 4-propylbenzene-1,3-diyl group.

Specific examples of the groups represented by A-R ^1- include tetrafluoroaryl group-containing groups such as 3- (2,3,4,5-tetrafluorophenyl) propyl group and 3- (3,4,5). -Trifluoroaryl group-containing group such as -trifluorophenyl) propyl group, difluoroaryl group-containing group such as 3- (3,4-difluorophenyl) propyl group, 3- (pentafluorophenyl) propyl group, 3- (p) − Trifluoromethylphenyl) Examples include fluoroalkylaryl group-containing groups such as propyl group.

In the above general formula (1), P may be the same or different, and represents an ethylenically unsaturated group having 2 to 10 carbon atoms, preferably 2 to 4 carbon atoms. Specific examples of P include an unsaturated alkyl group such as a vinyl group, an allyl group, a butenyl group and a metalyl group; an aryl group-containing unsaturated alkyl group such as a styryl group; an unsaturated group-containing aryl group; an acryloyloxy group and a methacryloyloxy group. Examples include unsaturated acyloxy groups such as groups. Among these, when P is an unsaturated asyloxy group, the silsesquioxane of the general formula (1) contains an α, β-unsaturated carboxylic acid ester structure, and has curing reactivity and other components of the composition. It is preferable from the viewpoint of compatibility with the constituent components.

In the above general formula (1), R ² may be the same or different, and represents a divalent hydrocarbon group or a single bond having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. However, ^{the bond between the group represented by PR 2-} and the silicon atom is substantially non-hydrolyzable.
Specific examples of the divalent hydrocarbon group having 1 to 10 carbon atoms of R ² include substituents similar to those of the specific example of ^{R 1.}

Specific examples of the group represented by PR ² − include a vinyl group, an allyl group, a butenyl group, a metalyl group, a 4-pentenyl group, a 5-hexenyl group, a 6-heptenyl group, a 4-vinylcyclohexyl group, and 7 Unsaturated aliphatic hydrocarbon groups such as −octenyl group, 9-decenyl group, 11-dodecenyl group, 13-tetradecenyl group; ethylenically unsaturated group-containing aromatic carbides such as styryl group, allylphenyl group and butenylphenyl group Hydrogen group; acryloyloxymethyl group, acryloyloxyethyl group, 3-acryloyloxypropyl group, 4-acryloyloxybutyl group, 5-acryloyloxypentyl group, 6-acryloyloxyhexyl group, 8-acryloyloxyoctyl group, 10- Acryloyloxydecyl group, methacryloyloxymethyl group, methacryloyloxyethyl group, 3-methacryloyloxypropyl group, 4-methacryloyloxybutyl group, 5-methacryloyloxypentyl group, 6-methacryloyloxyhexyl group, 8-methacryloyloxyoctyl group, Examples thereof include unsaturated asyloxy group-containing hydrocarbon groups such as 10-methacryloyloxydecyl group.

In the above general formula (1), m represents an integer of 4 to 400, preferably 6 to 300, and more preferably 6 to 100. When m is smaller than 4, the molecular weight of the compound of the general formula (1) is low, and it is easy to volatilize from the composition or the cured product. When m exceeds 400, the compatibility between the compound of the general formula (1) and other components contained in the composition of the present invention is lowered, and it is difficult to obtain a uniform composition.

Further, in the above general formula (1), n represents an integer of 1 to 100, preferably 1 to 50, and more preferably 1 to 10. Since the component (a) contains P, which is an ethylenically unsaturated group, in the molecule, the silsesquioxane of the general formula (1) bleeds out after the composition of the present invention is cured, and the physical properties of the cured product are improved. It can be prevented from changing.

m and n are 0.1 ≦ [m / (m + n)] <1, preferably 0.3 ≦ [m / (m + n)] <1, more preferably 0.5 ≦ [m / (m + n)] < The condition of 1 is satisfied. When the value of [m / (m + n)] is smaller than 0.1, the content of the fluorine-substituted aryl group contained in the compound of the general formula (1) is reduced, and the effect of improving the relative permittivity is small. Or, the thermal stability of the compound of the general formula (1) is lowered.

The polystyrene-equivalent number average molecular weight (Mn) of silsesquioxane having a fluorine-substituted aryl group of the general formula (1) by gel permeation chromatography (GPC) is the stability of the composition and compatibility with other components. From the above viewpoint, it is preferably 500 to 100,000, more preferably 800 to 50,000, still more preferably 1,000 to 30,000, and particularly preferably 1,000 to 10,000.
The dispersity (Mw / Mn) of silsesquioxane having a fluorine-substituted aryl group according to the general formula (1) is preferably 1 to 2.5, more preferably 1 to 2, from the viewpoint of material uniformity. 2, more preferably 1 to 1.7.

The silsesquioxane having a fluorine-substituted aryl group represented by the above general formula (1) added to the photocurable composition of the present invention may be a single compound or a mixture. When the compound of the general formula (1) is produced from hydrolyzable silane by the method described later, it is convenient to use it as a mixture.

In the photocurable composition of the present invention, the blending amount of silsesquioxane having a fluorine-substituted aryl group represented by the above general formula (1), which is a component (a), is the relative permittivity and mechanical properties of the cured product. Or, from the viewpoint of the transparency of the composition, the total amount with the component (b) described later is preferably 1 to 90% by mass, more preferably 10 to 85% by mass, and further preferably 20 to 80% by mass.
The total ratio of the component (a) and the component (b) described later to the entire composition is preferably 1 to 99% by mass, more preferably 10 to 90% by mass.

The silsesquioxane having a fluorine-substituted aryl group represented by the general formula (1) is, for example, a silane having a fluorine-substituted aryl group represented by the following general formula (2) and a silane having the following general formula (3). It can be produced by co-hydrolysis / condensation of the represented ethylenically unsaturated group.

Wherein, A and R ¹ represent the same substituents as A and R ¹ in the general formula (1).
X may be the same or different, and is a group that is hydrolyzable by binding to a silicon atom, and represents an organoxy group having 1 to 6 carbon atoms, an asyloxy group having 1 to 3 carbon atoms, or a halogen atom. Specific examples of X include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an isopropoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, an isopentyloxy group, and 2 -Alkoxy groups such as pentyloxy group, cyclopentyloxy group and cyclohexyloxy group; alkenoxy groups such as vinyloxy group and 2-propenoxy group; phenoxy group; asyloxy group such as acetoxy group, propanoyloxy group and butanoyloxy group; chlorine Examples thereof include halogen atoms such as atoms, bromine atoms and iodine atoms.

In the formula, P and R ² represent the same substituents as ^{P and R 2} in the general formula (1).
Y may be the same or different, and is a group that binds to a silicon atom and exhibits hydrolyzability, and represents an organoxy group having 1 to 6 carbon atoms, an asyloxy group having 1 to 3 carbon atoms, or a halogen atom. Specific examples of Y include the same substituents as those given as specific examples of X.

When producing silsesquioxane represented by the general formula (1), the silane represented by the general formula (2) and the silane represented by the general formula (3) are used alone. Alternatively, two or more kinds may be mixed and used.

The co-hydrolysis / condensation of the silane of the general formula (2) and the silane of the general formula (3) can be carried out by a known method. For example, a method of mixing the silane of the general formula (2), the silane of the general formula (3) and water in a solvent and reacting them can be adopted. In this case, the amount of the silane of the general formula (2) and the silane of the general formula (3) is preferably 0.0025 with respect to 1 mol of the silane of the general formula (3). It is 10 mol, more preferably 0.0025 to 2.5 mol, still more preferably 0.025 to 1 mol.

The above reaction proceeds without a solvent, but a solvent can also be used. Solvents include hydrocarbons such as hexane, heptane, octane, isooctane, decane, toluene, xylene, mesitylen; alcohols such as methanol, ethanol, propanol, 2-propanol, butanol, 2-butanol, tert-butanol; acetone, methyl ethyl ketone. , Ketones such as methyl isobutyl ketone; nitriles such as acetonitrile, propionitrile, benzonitrile; amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone; diethyl ether, tetrahydrofuran, cyclopentylmethyl ether, 1,2-dimethoxyethane and the like. Ether and the like can be mentioned.

By adding an acid or base as a catalyst to the reaction mixture, the co-hydrolysis / condensation reaction is accelerated.
Acids used as catalysts include carboxylic acids such as formic acid, acetic acid, propionic acid, citric acid and benzoic acid; sulfonic acids such as methanesulfonic acid, toluenesulfonic acid and dodecylbenzenesulfonic acid; hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid. Inorganic acids and the like can be mentioned.
Bases used as catalysts include amines such as ethyldimethylamine, diethylmethylamine, triethylamine, tributylamine, diisopropylethylamine, ammonia, sodium hydroxide, potassium hydroxide, cesium hydroxide, ammonium carbonate, sodium carbonate, potassium carbonate. , Inorganic bases such as ammonium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate and the like.

The reaction is accelerated by heating. Usually, the reaction is carried out below the reflux temperature of the solvent. The reaction temperature is preferably 0 to 200 ° C, more preferably 0 to 150 ° C, and even more preferably 0 to 100 ° C. The reaction time is preferably 1 to 60 hours, more preferably 1 to 30 hours, still more preferably 1 to 20 hours. The reaction atmosphere may be in the atmosphere, but it is preferably an atmosphere of an inert gas such as nitrogen or argon.

The silsesquioxane represented by the general formula (1) obtained by co-hydrolysis / condensation of the silanes of the general formulas (2) and (3) includes the non-hydrolyzed substituent X or Y, and Substituent OH that has been hydrolyzed and has not undergone condensation may remain. In silsesquioxane represented by the general formula (1), the proportion of silicon atoms to which the substituents X and Y and the OH group are bonded is determined from the viewpoint of the stability of the composition and the cured product of all silicon. Of the atoms, it is preferably 0 to 25 mol%, more preferably 0 to 15 mol%, still more preferably 0 to 10 mol%.

(B) Ethylene unsaturated monofunctional monomer Examples of the ethylenically unsaturated monofunctional monomer which is the component (b) of the present invention include a compound having an acryloyl group or a methacryloyl group, a compound having a vinyl group, and the like. Among these, α, β-unsaturated carboxylic acid esters such as acrylic acid ester and methacrylic acid ester have abundant structural variations, and the mechanical properties and thermal properties of the cured product can be arbitrarily adjusted. preferable.

Examples of the α, β-unsaturated carboxylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, propyl (meth) acrylate, isobutyl (meth) acrylate, and butyl (meth) acrylate. sec-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, carbitol (meth) acrylate, cyclohexyl (meth) acrylate , Tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, norbornanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate , Dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate and other (meth) acrylic acid esters.

Examples of the compound having a vinyl group include unsaturated amides such as N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, and acryloylmorpholin; (meth) acrylic acid, crotonic acid, and silicic acid. , Vinyl benzoic acid, maleic acid, fumaric acid, itaconic acid and other unsaturated carboxylic acids; styrene, α-methylstyrene, vinyltoluene, methoxystyrene and other aromatic vinyl compounds; methylmaleimide, ethylmaleimide, isopropylmaleimide, cyclohexylmaleimide , N-substituted maleimides such as phenylmaleimide, benzylmaleimide, naphthylmaleimide; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate; N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylacetamide, etc. N-vinylamide; allyl ethers such as allyl glycidyl ether and glycerin allyl ether can be mentioned.

The ethylenically unsaturated monofunctional monomer (b) component may be used alone or in combination of two or more. The physical characteristics of the cured product are determined by the type and compounding ratio of the monomer.

The blending amount of the component (b) in the photocurable composition of the present invention is preferably the total amount of the component (a) and the component (b) from the viewpoint of the uniformity of the composition or the electrical characteristics of the cured product. It is 10 to 99% by mass, more preferably 15 to 95% by mass, and even more preferably 20 to 90% by mass.

(C) Ethylene unsaturated polyfunctional monomer The ethylenically unsaturated polyfunctional monomer, which is the component (c) of the present invention, acts as a cross-linking agent. As the component (c), a compound containing a plurality of ethylenically unsaturated groups can be used. For example, α, β-unsaturated carboxylic acid ester of polyhydric alcohol, or a compound having a plurality of vinyl groups or a plurality of allyl groups can be used. Among these, α, β-unsaturated carboxylic acid esters of polyhydric alcohols are preferable because they have abundant structural variations and can arbitrarily adjust the mechanical properties of the cured product. The ethylenically unsaturated polyfunctional monomer (c) component may be used alone or in combination of two or more.

Among these ethylenically unsaturated polyfunctional monomers, examples of the α, β-unsaturated carboxylic acid ester of the polyhydric alcohol include bis (4- (meth) acryloxypolyethoxyphenyl) propane and neopentyl glycol di ( Meta) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) Α, β-unsaturated carboxylics of dihydric alcohols such as acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and tricyclodecanedimethanol di (meth) acrylate. Acid ester; α of trihydric alcohol such as trimethylpropantri (meth) acrylate; α of tetrahydric alcohol such as pentaerythritol tri (meth) acrylate and pentaerythritol tetra (meth) acrylate, β-unsaturated carboxylic acid ester; β-Unsaturated carboxylic acid ester; α, β-unsaturated carboxylic acid ester of a pentavalent or higher alcohol such as dipentaerythritol hexa (meth) acrylate can be mentioned.

Examples of the compound having a plurality of vinyl groups and allyl groups include diallyl phthalate, triallyl trimellitate, allyl (meth) acrylate, vinyl norbornene and the like.

In the photocurable composition of the present invention, the blending amount of the component (c) is the sum of the component (a) and the component (b) from the viewpoint of the solvent resistance of the cured product, the elongation of the cured product, the strength, and the like. On the other hand, it is preferably 0.001 to 20% by mass, and more preferably 0.01 to 10% by mass.

(D) Photopolymerization Initiator The photopolymerization initiator, which is the component (d) of the present invention, initiates photoradical polymerization. (D) Ingredients include intramolecular cleavage type photopolymerization initiators such as alkylphenones, benzoins, acylphosphine oxides, oxime esters, and biimidazoles, and hydrogens such as benzophenones, thioxanthones, and α-diketones. A pull-out type photopolymerization initiator or the like can be used.

Specific examples of the component (d) include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, and 2-hydroxy-2-methyl-1-phenylpropane-1. -On, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-) 2-Methylpropionyl) benzyl] phenyl} -2-methylpropan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino -1- (4-morpholinophenyl) -1-butanone, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone Alkylphenones such as; benzoins such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; (2,4,6-trimethylbenzoyl) diphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) ) Acylphosphine oxides such as phenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,4,4-trimethylpentylphosphine oxide; 1- [4- (phenylthio) -2- (O-benzoyloxime) )] Oxime esters such as -1,2-octanedione, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] -1- (O-acetyloxime) etanone; 2,2'-bis (2-chlorophenyl) -4,4', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis (2,4-dichlorophenyl) -4,4 ', 5,5'-Tetraphenyl-1,2'-biimidazole, 2,2'-bis (2,4,6-trichlorophenyl) -4,4', 5,5'-tetraphenyl-1, Biimidazoles such as 2'-biimidazole; benzophenones, 4,4'-bis (dimethylamino) benzophenones, benzophenones such as 2-carboxybenzophenone; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone , 2,4-Dimethylthioxanthone, 2,4-diethylthioxanthone and other thioxanthones; Examples thereof include α-diketones such as phenylquinone and benzyl.

These photopolymerization initiators can be used alone or in combination of any two or more. Among these photopolymerization initiators, alkylphenones are preferable from the viewpoint of compatibility in the photocurable composition.

The blending amount of the component (d) in the photocurable composition of the present invention is the component (a), the component (b) and (from the viewpoint of properties such as photocurability and flexibility and transparency of the obtained cured product). c) It is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, based on the total amount of the components.

Further, in addition to the above-mentioned photopolymerization initiator, a reducing compound can be used in combination for promoting polymerization. In particular, it is useful to combine a hydrogen abstraction type photopolymerization initiator and a reducing compound.
Typical examples of the reducing compound are aromatic tertiary amines, and specific examples thereof include aminobenzoic acids such as 4-dimethylaminobenzoic acid, 4-diethylaminobenzoic acid, and 3-dimethylaminobenzoic acid; 4 -Amino benzoate esters such as methyl dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, ethyl 4-diethylaminobenzoate, lauryl 4-dimethylaminobenzoate, ethyl 3-dimethylaminobenzoate; dimethylamino-p- Examples thereof include aniline derivatives such as toluidine, diethylamino-p-toluidine, and p-tolyldiethanolamine. Among these aromatic tertiary amines, aminobenzoic acid and aminobenzoic acid esters are preferable.
When such a reducing compound is used, the amount added thereof is usually in the range of preferably 0.001 to 20 mol, more preferably 0.005 to 10 mol, based on 1 mol of the photopolymerization initiator. ..

The photocurable composition of the present invention may optionally contain a solvent. Solvents include, for example, hydrocarbons such as hexane, heptane, octane, isooctane, decane, toluene, xylene, mesityrene; methanol, ethanol, propanol, 2-propanol, butanol, 2-butanol, tert-butanol, propylene glycol monomethyl ether. Alcohols such as: acetonitrile, propionitrile, benzonitrile, nitriles such as 3-methoxypropionitrile; amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone; diethyl ether, tetrahydrofuran, cyclopentylmethyl ether, 1,2- Ethers such as dimethoxyethane and anisole; esters such as ethyl acetate, isopropyl acetate and propylene glycol monomethyl ether acetate can be mentioned. These solvents may be used alone or in admixture of two or more, but when a plurality of these solvents are mixed, it is preferable to use solvents that are compatible with each other. .. Further, it is preferable that the solvent is one capable of dissolving the components of the photocurable composition of the present invention at room temperature.

When the solvent is added, the blending amount thereof is preferably 0.01 to 10 times by mass with respect to the total of the above-mentioned components (a) to (d). By curing while containing the solvent, a cured product is obtained as a gel. By removing the solvent after curing, it is possible to obtain a cured product containing no solvent.

The photocurable composition of the present invention is stable at room temperature under the condition of not irradiating light, but may contain a polymerization inhibitor as long as the properties of the composition such as transparency and curability can be maintained. .. Specific examples of the polymerization inhibitor include hydroquinones such as hydroquinone monomethyl ether, hydroquinone mono n-butyl ether, hydroquinone monobenzyl ether, hydroquinone monocyclohexyl ether, and 4-methoxy-1-naphthol; 2,6-bis (tert-butyl). ) -4-Methylphenol, octadecyl-3- (3,5-ditert-butyl-4-hydroxyphenyl) propionate, isooctyl-3- (3,5-ditert-butyl-4-hydroxyphenyl) propionate, 2 , 4-Bis- (n-octylthio) -6- (4-hydroxy-3,5-ditert-butylanilino) -1,3,5-triazine, 3,5-ditert-butyl-4-hydroxybenzylphos Hindered phenols such as phonate-diethyl ester and 6-tert-butyl-o-cresol; 6-tert-butyl-2,4-xylenol, 2,4,8,10-tetra-tert-butyl-6- [3- (3-Methyl-4-hydroxy-5-tert-butylphenyl) propoxy] dibenzo [d, f] [1,3,2] dioxaphosphepine, 2,4-dimethyl-6- (1) -Methylpentadecyl) phenol, 2,4-bis (octylthiomethyl) -o-cresol, 2,4-bis (dodecylthiomethyl) -o-cresol, 2-tert-butylphenol, 2,4-ditert- Examples thereof include semi-hindered phenols such as butylphenol, 2-tert-amylphenol, and 2,4-ditert-amylphenol. These polymerization inhibitors may be used alone or in combination of two or more.

When a polymerization inhibitor is added, the blending amount thereof is the component (a) and (b) from the viewpoint of improving the stability and preventing coloring while ensuring the curing reactivity of the photocurable composition of the present invention. It is preferably 0.001 to 2% by mass, more preferably 0.05 to 1% by mass, and further preferably 0.01 to 0.1% by mass with respect to the total of the components and the component (c).

The photocurable composition of the present invention can be obtained by mixing the above-mentioned components (a) to (d) and, if necessary, a solvent or a polymerization inhibitor, for example, at normal temperature (25 ° C.) and normal pressure. A mixing device such as a stirrer or various mixers can be used for mixing.
The photocurable composition of the present invention thus obtained is a uniform liquid at room temperature and is transparent.

<Cured product of photocurable composition>
The photocurable composition of the present invention can be cured by irradiating with light, and since the essential component (c) is a cross-linking agent, a polymer material composed of a cured product having a network-like structure can be obtained. Be done. Specifically, the composition is cured by irradiating it with light such as ultraviolet rays or visible light. The wavelength of the light to be irradiated is selected depending on the type of the photopolymerization initiator added, and is, for example, ultraviolet light of 254 nm, 365 nm (i line), 405 nm (h line), 436 nm (g line) or Visible light is most preferably used.

The amount of ultraviolet rays to be irradiated is preferably about ^{10 to 1,000 mJ / cm 2.} Further, if necessary, further heating may be performed at 50 to 200 ° C. after light irradiation. The heating time is arbitrary, but it is preferable to heat for 10 to 500 minutes. Further, in order to remove low molecular weight uncured matter and solvent, washing with a solvent or vacuum drying may be performed after light irradiation. Two or more of these post-treatments may be combined.

Since the photocurable composition of the present invention is liquid at room temperature, it can be cured by using a mold, or it can be applied on a substrate and cured as a thin film.

The cured product obtained by curing the photocurable composition of the present invention is a crosslinked polymer material. (A) The addition of the component improves the electrical properties such as the relative permittivity of the material. By selecting the component (b) and the component (c), it is possible to adjust the physical properties such as mechanical properties, thermal properties, and adhesiveness of the cured product. Since the component (a) of the present invention generally has good compatibility with the component (b) and the component (c), the transparency is often maintained even after curing.

Hereinafter, the present invention will be described in more detail with reference to Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Synthesis Example 1] [3- (acryloyloxy) propyl] [3- (3,4,5-trifluorophenyl) propyl] Synthesis of silsesquioxane (SSQ1) Stirrer, thermometer, reflux condenser, dropping A 100 mL four-necked round-bottom flask equipped with a funnel was replaced with nitrogen, and nitrogen was aerated over the reflux condenser opened to the outside air to block air and moisture. 14.72 g (50.0 mmol) of 3- (3,4,5-trifluorophenyl) propyltrimethoxysilane, 1.17 g (5.0 mmol) of 3- (acryloyloxy) propyltrimethoxysilane in the flask. 0.28 g (2.8 mmol) of triethylamine and 15 g of acetone were charged, and the internal temperature was adjusted to 50 ° C. while stirring the contents. 2.97 g (165 mmol) of deionized water was added, and the reaction was carried out at 50 ° C. for 12 hours while monitoring the progress of the reaction by gel permeation chromatography (GPC). The obtained colorless and transparent solution was concentrated under reduced pressure using a rotary evaporator, and the residue was vacuum-heated and dried at 80 ° C. to obtain a viscous oil.

When the GPC measurement of this oily substance was performed, the weight average molecular weight (Mw) of the main peak was 4,732, the number average molecular weight (Mn) was 3,573 (polystyrene conversion by GPC, respectively), and the dispersity (Mw). / Mn) was 1.324.

The infrared absorption spectrum of this solid is shown in FIG. Stretching vibration peak of the carbonyl group of the acrylic acid ester to 1,724cm ^-1, expansion and contraction of the Si-O bond on the stretching vibration peak and 1,000～1,100Cm ^-1 vinyl group of the acrylic acid ester 1,621Cm ^-1 Since the vibration peak was observed, it was judged that the desired silsesquioxane (SSQ1) was obtained.

[Synthesis Example 2] [3- (Acryloyloxy) propyl] [3- (3,4-difluorophenyl) propyl] Synthesis of silsesquioxane (SSQ2) A stirrer, a thermometer, a reflux condenser, and a dropping funnel are provided. A 100 mL four-necked round-bottom flask was replaced with nitrogen, and nitrogen was aerated over the reflux condenser opened to the outside air to block air and moisture. In the flask, 19.35 g (70.0 mmol) of 3- (3,4-difluorophenyl) propyltrimethoxysilane, 1.64 g (7.0 mmol) of 3- (acryloyloxy) propyltrimethoxysilane, triethylamine 0. 39 g (3.9 mmol) and 21 g of acetone were charged, and the internal temperature was adjusted to 50 ° C. while stirring the contents. 4.16 g (231 mmol) of deionized water was added, and the reaction was carried out at 50 ° C. for 18 hours while monitoring the progress of the reaction by gel permeation chromatography (GPC). The obtained colorless and transparent solution was concentrated under reduced pressure using a rotary evaporator, and the residue was vacuum-heated and dried at 80 ° C. to obtain 15.58 g of a viscous oil.

When the GPC measurement of this oil was performed, the weight average molecular weight (Mw) of the main peak was 5,882, the number average molecular weight (Mn) was 4,081 (each converted to polystyrene by GPC), and the degree of dispersion (each was converted to polystyrene by GPC). Mw / Mn) was 1.441.

The infrared absorption spectrum of this solid is shown in FIG. 1,724 cm ^-1 is the expansion and contraction vibration peak of the carbonyl group of the acrylic acid ester, 1,609 cm ^-1 is the expansion and contraction vibration peak of the vinyl group of the acrylic acid ester, and 1,000 to ^{1,100 cm -1} is the Si—O bond. Since the expansion and contraction vibration peak was observed, it was judged that the desired silsesquioxane (SSQ2) was obtained.

[Synthesis Example 3] [3- (Acryloyloxy) propyl] [3- (Pentafluorophenyl) propyl] Synthesis of silsesquioxane (SSQ3) 100 mL equipped with a stirrer, thermometer, reflux condenser, and dropping funnel. The four-necked round-bottom flask was replaced with nitrogen, and nitrogen was aerated over the reflux condenser opened to the outside air to block air and moisture. 16.52 g (50.0 mmol) of 3- (pentafluorophenyl) propyltrimethoxysilane, 1.17 g (5.0 mmol) of 3- (acryloyloxy) propyltrimethoxysilane, 0.28 g (2) of triethylamine in the flask. 8.8 mmol) and 15 g of acetone were charged, and the internal temperature was adjusted to 50 ° C. while stirring the contents. 2.97 g (165 mmol) of deionized water was added, and the reaction was carried out at 50 ° C. for 12 hours while monitoring the progress of the reaction by gel permeation chromatography (GPC). The obtained colorless and transparent solution was concentrated under reduced pressure using a rotary evaporator, and the residue was vacuum-heated and dried at 80 ° C. to obtain a viscous oil.

When the GPC measurement of this oil was performed, the weight average molecular weight (Mw) of the main peak was 4,499, the number average molecular weight (Mn) was 3,403 (polystyrene conversion by GPC, respectively), and the degree of dispersion (each was converted to polystyrene by GPC). Mw / Mn) was 1.322.

The infrared absorption spectrum of this solid is shown in FIG. Stretching vibration peak of the carbonyl group of the acrylic acid ester to 1,728cm ^-1, expansion and contraction of the Si-O bond on the stretching vibration peak and 1,000～1,100Cm ^-1 vinyl group of the acrylic acid ester 1,656Cm ^-1 Since the vibration peak was observed, it was judged that the desired silsesquioxane (SSQ3) was obtained.

[Synthesis Example 4] [3- (Acryloyloxy) propyl] [3- (p-trifluoromethylphenyl) propyl] Synthesis of silsesquioxane (SSQ4) A stirrer, a thermometer, a reflux condenser, and a dropping funnel are provided. A 100 mL four-necked round-bottom flask was replaced with nitrogen, and nitrogen was aerated over the reflux condenser opened to the outside air to block air and moisture. In the flask, 14.72 g (50.0 mmol) of 3- (p-trifluoromethylphenyl) propyltrimethoxysilane, 1.17 g (5.0 mmol) of 3- (acryloyloxy) propyltrimethoxysilane, triethylamine 0. 28 g (2.8 mmol) and 15 g of acetone were charged, and the internal temperature was adjusted to 50 ° C. while stirring the contents. 2.97 g (165 mmol) of deionized water was added, and the reaction was carried out at 50 ° C. for 12 hours while monitoring the progress of the reaction by gel permeation chromatography (GPC). The obtained colorless and transparent solution was concentrated under reduced pressure using a rotary evaporator, and the residue was vacuum-heated and dried at 80 ° C. to obtain 12.72 g of a viscous oil.

When the GPC measurement of this oil was performed, the weight average molecular weight (Mw) of the main peak was 11,020, the number average molecular weight (Mn) was 6,840 (polystyrene conversion by GPC, respectively), and the dispersity (each). Mw / Mn) was 1.611.

The infrared absorption spectrum of this solid is shown in FIG. Stretching vibration peak of the carbonyl group of the acrylic acid ester to 1,725cm ^-1, expansion and contraction of the Si-O bond on the stretching vibration peak and 1,000～1,100Cm ^-1 vinyl group of the acrylic acid ester 1,619Cm ^-1 Since the vibration peak was observed, it was judged that the desired silsesquioxane (SSQ4) was obtained.

[Examples 1 to 3 and Comparative Example 1]
The component (a) is silsesquioxane (SSQ1) obtained in Synthesis Example 1, the component (b) is ethyl acrylate (EA), and the component (c) is 1,4-butanediol diacrylate (BDA), (d). ) As a component, 2-hydroxy-2-methyl-1-phenylpropane-1-one (HMP) was mixed at the blending ratio shown in Table 1 using a rotation / revolution type mixer to obtain a photocurable composition.
Further, the photocurable composition of Comparative Example 1 was obtained by mixing the other components excluding the component (a) at the blending ratios shown in Table 1.

The obtained liquid composition is filled in a quartz glass mold having a depth of 1 mm, visually observed, and then cured by irradiating ultraviolet light having a central wavelength of 365 nm in a nitrogen atmosphere to form a rubber. E1, E2, E3 and C1 of the cured products of the above were obtained.

Table 2 shows the visual appearance, relative permittivity (1 kHz, 20 ° C.), and dielectric loss tangent (1 kHz, 20 ° C.) of the cured products E1, E2, E3, and C1. The relative permittivity and the dielectric loss tangent were measured by the LCR meter E4980A manufactured by Keysight Technologies and the dielectric test fixture 16451B.

[Examples 4 to 10]
(A) As a component, silsesquioxane (SSQ2) obtained in Synthesis Example 2, silsesquioxane (SSQ3) obtained in Synthesis Example 3, or silsesquioxane (SSQ4) obtained in Synthesis Example 4, EA as the component (b), BDA as the component (c), and HMP as the component (d) were mixed at the blending ratios shown in Table 3 to obtain the photocurable compositions of Examples 4 to 10. The obtained liquid composition was cured in the same manner as in Examples 1 to 3 to obtain rubber-like cured products E4 to E10.

Table 4 shows the appearance, relative permittivity (1 kHz, 25 ° C.) and dielectric loss tangent (1 kHz, 25 ° C.) of the cured products E4 to E10.

The polymer material, which is a cured product obtained from the photocurable composition of the present invention, has a high relative permittivity, and the electrical and mechanical properties can be adjusted by appropriately selecting the type and composition of the constituent monomers. Therefore, it can be used as an insulating film for polymer actuators and organic transistors.

Claims (6)

(A) The following general formula (1)

(In the formula, A may be the same or different, represents an aryl group having 6 to 25 carbon atoms, and at least one of the hydrogen atoms of the aryl group is substituted with a fluorine atom (the fluorine atom is A). It may be directly bonded to the aryl group constituting the above, or if A has an alkyl substituent, it may be bonded to the alkyl group). P may be the same or different, and has 2 carbon atoms. Represents an ethylenically unsaturated group of ^{10. R 1} may be the same or different and represents a divalent hydrocarbon group having 1 to 10 carbon atoms. R ² may be the same or different and has 1 carbon number. It represents a divalent hydrocarbon group or a single bond of 10 to 10. However, ^{the bond between the group represented by PR 2-} and the silicon atom is substantially non-hydrolytable. M is 4 to 4 to. An integer of 400, n represents an integer of 1 to 100, and the condition of 0.1 ≦ [m / (m + n)] <1 is satisfied.)
Silsesquioxane having a fluorine-substituted aryl group represented by
(B) One or more kinds of ethylenically unsaturated monofunctional monomers,
A photocurable composition comprising (c) one or more kinds of ethylenically unsaturated polyfunctional monomers and (d) a photopolymerization initiator as essential components. The first aspect of the above formula (1), wherein A is a phenyl group or an alkyl-substituted phenyl group, and at least one of the hydrogen atoms of the phenyl group or the alkyl group is substituted with a fluorine atom. Photocurable composition. The photocurable composition according to claim 1 or 2, wherein in the above formula (1), P is a group selected from a vinyl group, an allyl group, a butenyl group, a metallicyl group, an acryloyloxy group and a methacryloyloxy group. The photocurable composition according to any one of claims 1 to 3, wherein the component (b) is an α, β-unsaturated carboxylic acid ester. The photocurable composition according to any one of claims 1 to 4, wherein the component (c) is an α, β-unsaturated carboxylic acid ester of a polyhydric alcohol. A cured product of the photocurable composition according to any one of claims 1 to 5.

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