WO2023037941A1 - High energy ray-curable composition and use of same - Google Patents

Abstract

[Problem] To provide a silicon-atom-containing high energy ray-curable composition that enables a product, which is obtained by curing the composition, to be highly regulated with respect to the mechanical properties, while having excellent workability when applied to a base material even in cases where the high composition is of solvent-free type. [Solution] A high energy ray-curable composition which is characterized by containing 5 parts by mass to 95 parts by mass of (A) a compound that has one or more (meth)acryloxy groups and no silicon atom in each molecule, and 95 parts by mass to 5 parts by mass of (B) a branched organopolysiloxane that has one or more (meth)acryloxy groups and no alkoxy group in each molecule, and which is also characterized by substantially containing no organic solvent in the composition and having a viscosity of the entire composition of 100 mPa∙s or less as determined with use of an E-type viscometer at 25°C; and a use of this high energy ray-curable composition.

Description

High-energy radiation-curable composition and use thereof

The present invention relates to high energy radiation curable compositions curable by actinic rays, e.g. , relates to a high-energy ray-curable composition having low viscosity and excellent applicability. Since the cured product obtained therefrom exhibits a low dielectric constant, the curable composition of the present invention is suitable as a material for use as an insulating material, particularly as a coating agent, for electronic and electrical devices. Furthermore, it has excellent applicability and excellent wettability to substrates, and is useful as an injection molding material and an inkjet printing material.

Due to its high heat resistance and excellent chemical stability, silicone resins have been used as coating agents, potting agents, insulating materials, etc. for electronic and electrical devices. Among silicone resins, high-energy ray-curable silicone compositions have also been reported so far.

Touch panels are used in various display devices such as mobile devices, industrial equipment, and car navigation systems. In order to improve the detection sensitivity, it is necessary to suppress the electrical influence from the light emitting parts such as light emitting diodes (LED) and organic EL devices (OLED). placed.

On the other hand, thin display devices such as OLED have a structure in which many functional thin layers are laminated. In recent years, studies have begun to improve the reliability of display devices, particularly flexible display devices as a whole, by laminating a highly flexible insulating layer on a touch screen layer. Further, for the purpose of improving productivity, an inkjet printing method is adopted as a method for processing an organic layer. Therefore, a non-solvent type material that can be processed by an inkjet printing method is also required for the insulating layer.

Patent Document 1 (European Patent Publication No. 2720085) describes a high-energy ray-curable composition comprising a monomer having a (meth)acryloxy functional group and a silane having a (meth)acryloxy functional group, and a composition obtained from the composition. A barrier layer is disclosed. Further, in Patent Document 2 (International Patent Application Publication No. WO2018-3381), linear silicone having 12 or more silicon atoms with (meth)acryloxy functionality at both ends and a monomer having a (meth)acryloxy functional group A high-energy ray-curable inkjet ink composition comprising: Although both compositions have low viscosities, dielectric properties of the cured products thereof are neither described nor suggested.

Patent Document 3 (Japanese Unexamined Patent Application Publication No. 2020-70358) discloses a radiation-curable organosilicon resin composition having excellent gas barrier properties, comprising linear silicone having 3 or less silicon atoms with (meth)acryloxy functionality at both ends. things are disclosed. Although the composition disclosed therein has a low molecular weight, it has a high viscosity, which limits the processing method and is not suitable for application by an inkjet method.

Furthermore, in Patent Document 4 (Japanese Patent Application Laid-Open No. 2020-53313), a monomer having a (meth)acryloxy functional group and a silicone compound having a methoxy group are used for inkjet printable high energy ray curing for organic EL sealing. A flexible resin composition is disclosed. A large number of methoxy groups present in the composition improve the adhesiveness to the substrate, but there is a concern that the physical properties of the composition such as viscosity may change due to moisture absorption. In addition, methoxy groups and silanol groups generated by moisture absorption have anisotropy, which is not preferable as a low dielectric material.

As described above, many high-energy ray-curable compositions containing organopolysiloxanes having (meth)acryloxy functional groups are known. A high-energy ray-curable composition which has excellent workability, especially low viscosity, and whose cured product has a low dielectric constant still has problems to be solved.

European Patent Publication No. 2720085 International Patent Application Publication No. WO2018/3381 Pamphlet JP 2020-70358 A JP 2020-53313 A

The present invention makes it easy to adjust the mechanical properties of the cured product, allows designing hardness etc. in a wide range, and has excellent workability when applied to a substrate even if it is a solventless type. The object of the present invention is to provide a curable composition containing silicon atoms, particularly a high-energy ray-curable composition, which gives a cured product having a low dielectric constant.

The present invention provides (A) 5 to 95 parts by mass of a compound having one or more (meth)acryloxy groups in one molecule and no silicon atoms, and (B) one or more (meth)acryloxy groups in one molecule. ) Branched organopolysiloxane having an acryloxy group and not having an alkoxy group A high-energy radiation-curable composition obtained by using 95 to 5 parts by mass in combination, even if substantially no organic solvent is used, It was completed by discovering that it has a low viscosity, is excellent in workability when applied to a substrate, and exhibits excellent mechanical properties and dielectric properties in its cured product.

The present invention relates to high-energy ray-curable compositions comprising organosilicon compounds, particularly UV-curable organopolysiloxane compositions, which cure by forming bonds with UV-curable functional groups. However, the curing method is not limited to ultraviolet irradiation, and any method that allows the curable functional group to undergo a curing reaction can be used, for example, electron beam irradiation can be used to cure the composition of the present invention. You may let

The high-energy ray-curable composition of the present invention is
(A) a compound having one or more (meth)acryloxy groups in one molecule and no silicon atoms, 5 to 95 parts by mass, and (B) one or more (meth)acryloxy groups in one molecule and contains 95 to 5 parts by mass of branched organopolysiloxane having no alkoxy group, and the viscosity of the entire composition measured at 25 ° C. using an E-type viscometer is 100 mPa s or less, and the composition The product is characterized by being substantially free of organic solvents. Unless otherwise specified in this specification, the viscosity of a substance is a value measured using an E-type viscometer at 25°C.

Component (A) in the curable composition is a compound having one (meth)acryloxy group and no silicon atom or two or more kinds of compounds having one (meth)acryloxy group and no silicon atom It may be a mixture of compounds.

The above component (A) comprises one or more compounds having one (meth)acryloxy group and no silicon atom and one or more compounds having two or more (meth)acryloxy groups and no silicon atom. A mixture may be used.

The above component (A) may be a compound having one or more acryloxy groups in one molecule and no silicon atoms.

The above component (A) may be a compound having one (meth)acryloxy group in one molecule and no silicon atom.

Component (B) in the curable composition has an average composition formula:
R _a R′ _b SiO _(4-ab)/2 (1)
(Wherein, R is a (meth) acryloxy group-containing group,
R′ is a group selected from unsubstituted or fluorine-substituted monovalent hydrocarbon groups and hydroxyl groups, and a and b satisfy the following conditions: 1≦a+b<3 and 0.01≦a/(a+b)< A number that satisfies 1.0 and has at least one R in the molecule. )
A branched organopolysiloxane represented by is preferred.

The above component (B) has an average unit formula:
(X ₃ SiO _1/2 ) _c (X ₂ SiO _2/2 ) _d (XSiO _3/2 ) _e (SiO _4/2 ) _f (2)
(Wherein, X is each independently a group selected from (meth)acryloxy group-containing groups, unsubstituted or fluorine-substituted monovalent hydrocarbon groups, and hydroxyl groups, and among all X, at least one is a (meth)acryloxy group-containing group, (e + f) is a positive number, c is 0 or a positive number, and d is a number within the range of 0 to 100). Polysiloxane is preferred.

The above component (B) is preferably a branched organopolysiloxane having alkenyl groups.

The above component (B) is preferably a branched organopolysiloxane having two or more (meth)acryloxy groups in one molecule and no alkoxy groups.

The viscosity of the entire composition measured at 25°C using an E-type viscometer is preferably in the range of 5 to 30 mPa·s.

The present invention further provides an insulating coating agent containing the above high-energy ray-curable composition. The high-energy ray-curable composition of the present invention is useful as an insulating coating agent.

The present invention further provides a cured product of the above high-energy ray-curable composition. Also provided is a method of using the cured product as an insulating coating layer.

The present invention further provides a display device, such as a liquid crystal display, an organic EL display, and an organic EL flexible display, including a layer comprising a cured product of the above-described high-energy ray-curable composition.

The high-energy ray-curable composition of the present invention is solvent-free, yet has an appropriate viscosity that provides good workability when applied to a substrate, and excellent wettability. etc., can be designed in a wide range and has the advantage of having a low dielectric constant. Furthermore, since the physical properties of the composition do not easily change, the composition has excellent storage stability and can maintain good coatability and curability over a long period of time. Therefore, the high-energy ray-curable composition according to the present invention can be used as a material for forming a low dielectric constant layer, particularly a low dielectric constant material for electronic devices, in any field where a material having a low dielectric constant is required. It is useful as a material for insulating layers, especially as a coating material.

The configuration of the present invention will be described in more detail below.
The high-energy ray-curable composition of the present invention is
(A) 5 to 95 parts by mass of a compound having one or more (meth)acryloxy groups in one molecule and having no silicon atoms, and (B) one or more (meth)acryloxy groups in one molecule 95 to 5 parts by mass of a branched organopolysiloxane having no alkoxy group as an essential component for curing, and if necessary, a component selected from a photoradical polymerization initiator and various additives. can be done. However, the curable composition of the present invention is characterized by being substantially free of organic solvents. In addition, in this specification, "(meth)acryloxy group" means a group selected from a methacryloxy group and an acryloxy group, and may include both. Also, compounds having a (meth)acryloxy group include both methacrylate compounds and acrylate compounds.

As used herein, the term "polysiloxane" refers to a siloxane unit (Si—O) having a degree of polymerization of 2 or more, that is, having an average of 2 or more Si—O bonds per molecule. It includes siloxane oligomers such as disiloxanes, trisiloxanes, tetrasiloxanes, etc., to siloxane polymers with a higher degree of polymerization. In component (B), part of the siloxane structure between silicon atoms represented by Si—O—Si is substituted with alkylene having 6 or less carbon atoms (preferably in the range of 2 to 6). and those having a silalkylene structure.

[Component (A)]
Component (A) is a compound having one or more (meth)acryloxy groups in one molecule and having no silicon atoms. The molecular structure is not limited as long as it can achieve this purpose, and may be linear, branched, cyclic, cage-like, or any other structure.

The component (A) preferably has a viscosity at 25°C of 1 to 500 mPa·s, more preferably 1 to 100 mPa·s, and particularly preferably 1 to 20 mPa·s.

In addition, the component (A) contains 1 to 4, preferably 1 to 3, more preferably 1 to 2 (meth)acryloxy groups per molecule. In a compound having a plurality of (meth)acryloxy groups, the positions of the (meth)acryloxy groups in the molecule are not particularly limited, and may be adjacent or separated.

The component (A) may be a single compound having one (meth)acryloxy group, or a mixture of two or more compounds having one (meth)acryloxy group.

Furthermore, the component (A) may be a mixture of one or more compounds having one (meth)acryloxy group and a compound having two or more (meth)acryloxy groups. However, considering the viscosity of the composition as a whole, it is preferable that one or more compounds having one (meth)acryloxy group constitute the main component of component (A).

Furthermore, the component (A) may be one or more compounds having one acryloxy group, or one or more compounds having one acryloxy group and one or more compounds having two or more acryloxy groups. A mixture may be used. However, as with the above, it is preferred that one or more compounds having one acryloxy group constitute the main component of component (A).

Specific examples of compounds having one (meth)acryloxy group include isoamyl acrylate, isoamyl methacrylate, octyl acrylate, octyl methacrylate, dodecyl acrylate, dodecyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, and diethylene glycol monoethyl ether. Acrylates, diethylene glycol monoethyl ether methacrylate, diethylene glycol monomethyl ether acrylate, diethylene glycol monomethyl ether methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, diethylene glycol monophenyl ether acrylate, diethylene glycol monophenyl ether methacrylate, 4- Hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, isobornyl acrylate, isobornyl methacrylate, dicyclopentanyl acrylate, dicyclo Pentanyl methacrylate, dicyclopentenyl acrylate, dicyclopentenyl methacrylate, 3,3,5-tricyclohexyl acrylate, 3,3,5-tricyclohexyl methacrylate, and the like, and these alone It may be used or a mixture of two or more may be used.

The compound having one (meth)acryloxy group can be used alone or in combination of two or more, taking into consideration the viscosity, curability, hardness after curing, and glass transition temperature of the compound. Among them, acrylate compounds or methacrylate compounds having 8 or more carbon atoms in the molecule are preferable from the viewpoint of providing low volatility, low viscosity of the composition, and high glass transition temperature of the cured product. , 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, dicyclopentanyl acrylate, dicyclopentanyl methacrylate, dicyclopentenyl acrylate and dicyclopentenyl methacrylate are preferred. Available.

Specific examples of compounds having two or more (meth)acryloxy groups include diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, and polyethylene. Glycol diacrylate, polyethylene glycol dimethacrylate, 1,4-bis(acryloyloxy)butane, 1,4-bis(methacryloyloxy)butane, 1,6-bis(acryloyloxy)hexane, 1,6-bis(methacryloyloxy) ) Hexane, 1,9-bis(acryloyloxy)nonane, 1,9-bis(methacryloyloxy)nonane, tricyclodecanedimethanol diacrylate, tricyclodecanedimethanol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tris(2-acryloyloxy)ethylisosialate, tris(2-methacryloyloxy)ethylisosialate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate and the like.

With respect to the compound having two or more (meth)acryloxy groups, taking into account the viscosity of the compound, curability, compatibility with the compound having one (meth)acryloxy group, hardness after curing, and glass transition temperature, They can be used singly or in combination of two or more. Diethylene glycol diacrylate, diethylene glycol dimethacrylate, 1,6-bis(acryloyloxy)hexane, 1,6-bis(methacryloyloxy)hexane, tricyclodecanedimethanol diacrylate, tricyclodecanedimethanol dimethacrylate, trimethylolpropane tri Acrylates, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, and pentaerythritol tetramethacrylate can be preferably used.

Furthermore, in consideration of the above physical properties, it is also possible to use a compound having two or more (meth)acryloxy groups and a compound having one (meth)acryloxy group in combination. In this case, both can be combined in any ratio, but usually [compound having two or more (meth)acryloxy groups]/[compound having one (meth)acryloxy group] is 0/100 to 50/ 50 (mass ratio). This is because if the ratio of the polyfunctional compound having two or more (meth)acryloxy groups is too high, the viscosity of the composition as a whole will be high, and the cured product will tend to be brittle. In particular, a monofunctional acrylate compound or methacrylate compound having one (meth)acryloxy group may be used alone and is preferred.

[Component (B)]
Component (B) is a branched organopolysiloxane having one or more silicon-bonded (meth)acryloxy group-containing organic groups per molecule and no alkoxy groups. Having a branched structure has the effect of increasing the mechanical strength of the cured product, particularly the elastic modulus.

The above component (B) has the following average composition formula:
R _a R′ _b SiO _(4-ab)/2 (1)
(Wherein, R is a (meth) acryloxy group-containing organic group,
R′ is a group selected from unsubstituted or fluorine-substituted monovalent hydrocarbon groups and hydroxyl groups, and a and b satisfy the following conditions: 1≦a+b<3 and 0.01≦a/(a+b)< A number that satisfies 1.0 and has at least one R in the molecule. )
It can be a branched organopolysiloxane represented by

　　（３）
（式中、Ｒ^１は水素原子またはメチル基であり、ｘは２以上１０以下の数であり、＊で表される分岐状ポリシロキサンを構成するケイ素原子と結合する）

　　（４）
（式中、Ｒ^１は水素原子またはメチル基であり、Ｒ^２は炭素原子数が１から２０の一価炭化水素基であり、ｘは２以上１０以下の数であり、ｙは０以上３以下の数であり、ｚは１以上の数であり、＊で表される分岐状ポリシロキサンを構成するケイ素原子と結合する） As the (meth)acryloxy group-containing group represented by R in Formula (1), a group represented by Formula (3) or (4) below is preferable.

(3)
(Wherein, R ¹ is a hydrogen atom or a methyl group, x is a number of 2 or more and 10 or less, and is bonded to the silicon atom constituting the branched polysiloxane represented by *)

(4)
(wherein R ¹ is a hydrogen atom or a methyl group, R ² is a monovalent hydrocarbon group having 1 to 20 carbon atoms, x is a number of 2 or more and 10 or less, and y is 0 or more and 3 is the following number, z is a number of 1 or more, and is bonded to the silicon atom that constitutes the branched polysiloxane represented by *)

The branched organopolysiloxane represented by the average composition formula has at least one (meth)acryloxy group-containing group on average per molecule. From the viewpoint of the stability of the cured product at high temperatures, the number of (meth)acryloxy group-containing groups per molecule is preferably more than 1 on average, preferably 2 to 8, more preferably 2 to 4. be.

R' is a group selected from unsubstituted or fluorine-substituted monovalent hydrocarbon groups and hydroxyl groups. The unsubstituted or fluorine-substituted monovalent hydrocarbon group is preferably a group selected from unsubstituted or fluorine-substituted alkyl, cycloalkyl, arylalkyl, and aryl groups having 1 to 20 carbon atoms. be. Examples of the alkyl group include groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, pentyl, hexyl and octyl, with methyl and hexyl being particularly preferred. . Examples of the cycloalkyl group include cyclopentyl and cyclohexyl. Examples of the arylalkyl group include benzyl and phenylethyl groups. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of fluorine-substituted monovalent hydrocarbon groups include 3,3,3-trifluoropropyl and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. but the 3,3,3-trifluoropropyl group is preferred.

The substituent R ² is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and an unsubstituted monovalent hydrocarbon group for R′ can be applied.

The organopolysiloxane represented by the above formula (1) has a viscosity at 25°C of 5 to 2,000 mPa·s, 5 to 1,000 mPa·s, most preferably 5 to 500 mPa·s. The viscosity of the organopolysiloxane can be adjusted by varying the ratio of a and b in formula (1) and the molecular weight.

The organopolysiloxane represented by the above formula (1) preferably has an average of 4 to 50, more preferably 4 to 30, and particularly preferably 4 to 20 silicon atoms per molecule.

In one preferred embodiment, component (B) organopolysiloxane is
The following average unit formula (2):
(X ₃ SiO _1/2 ) _c (X ₂ SiO _2/2 ) _d (XSiO _3/2 ) _e (SiO _4/2 ) _f (2)
It is a branched organopolysiloxane represented by
(Wherein, X is each independently a group selected from (meth)acryloxy group-containing groups, unsubstituted or fluorine-substituted monovalent hydrocarbon groups, and hydroxyl groups, and among all X, at least one is a (meth)acryloxy group-containing group, (e+f) is a positive number, c is 0 or a positive number, and d is a number within the range of 0 to 100)

Similar to the branched organopolysiloxane represented by the formula (1), the branched organopolysiloxane represented by the formula (2) has an average of one or more (meth)acryloxy group-containing groups per molecule. have The average number of (meth)acryloxy group-containing groups per molecule is preferably 2 to 8, more preferably 2 to 4. The structure of the (meth)acryloxy group-containing group is not limited as long as it has a (meth)acryloxy group, but a group represented by the above formula (3) or (4) is preferable.

In formula (2), the substituents other than the high-energy ray-curable functional group on the silicon atom are as defined for formula (1) above. Also, the preferred viscosity of the branched organopolysiloxane represented by formula (2) is as defined in formula (1).

The organopolysiloxane represented by formula (2) preferably has 4 to 30, particularly 4 to 20 silicon atoms per molecule.

In one preferred embodiment, component (B), particularly the branched organopolysiloxane of formula (2), is a branched organopolysiloxane having (RSiO _3/2 ) units.

Furthermore, in one preferred embodiment, component (B) can be a branched organopolysiloxane having one or more alkenyl groups in its molecule. Here, since the alkenyl group has reactivity with the (meth)acryloxy group of the component (A), it is useful for adjusting the degree of cure of the curable composition as well as the hardness and elastic modulus of the cured product.

Specific examples of the branched organopolysiloxane represented by the above formula (1), especially the above formula (2) include polysiloxanes composed of combinations of the following siloxy units. Here, M is a trimethylsiloxy unit, ^MVi is a dimethylvinylsiloxy unit, ^MMA is a triorganosiloxy unit containing a methacryloxy-containing organic group represented by _{RMe2SiO1 /2} , ^MA is _RMe2 triorganosiloxy units containing acryloxy-containing organic groups represented by SiO _1/2 , D is dimethylsiloxy units, D ^Vi is methylvinylsiloxy units, D ^Hex is methylhexenylsiloxy units, ^DMA is RMeSiO _{2 /2} , D ^A is a diorganosiloxy unit containing an acryloxy-containing organic group represented by RMeSiO _2/2 , T is a methylsiloxy unit, T ^Ph is a , a phenylsiloxy unit, T ^Hex is a hexenylsiloxy unit, T ^MA is an organosiloxy unit containing a methacryloxy-containing organic group represented by RSiO _3/2 , ^TA is an acryloxy-containing organic group represented by RSiO _3/2 An organosiloxy unit containing a group, Q, represents a siloxy unit without an organic group. The content of each siloxy unit (in particular, the values of c, d, e, and f corresponding to each unit), the viscosity, and the number of silicon atoms contained in the branched organopolysiloxane composed of these structural units are the same as those described above. It is the same as the branched organopolysiloxane represented by the average unit formula (2). In addition, in the examples of combinations below, the specific number of each siloxy unit is omitted.
Examples of combinations of siloxy units that make up branched organopolysiloxanes:
MT ^MA , ^MTA , MM ^Vi T ^MA , MM ^Vi T ^A , MDT ^MA , MDTA , MD ^Vi T ^MA , MD ^Vi T ^A , MD ^Hex T ^MA , MD ^{Hex T A} , MD ^Vi T ^Ph T ^MA , MD ^{ViTPhTA , MD HexTPhTMA , MDHexTPhTA , MDMAT , MDAT , MDMATPh , MDATPh , MDViDMAT , MDViDAT ,} MD ^{Hex DMA} T, MD ^{Hex DA} T, MD ^{Vi DMA} T ^Ph , MD Vi ^DA T ^Ph , MD ^{Hex DMA} T ^Ph , MD ^{Hex DA T Ph} , MM ^{Vi DMA} T, MM ^{Vi DA} T, MM ^{Vi DMA} T ^Ph , MM ^Vi DA ^{T Ph ,} MMA DT, ^{M A} DT, M ^MA DT Ph, M ^A DT ^Ph , MM ^MA DT, MM ^A DT, MM ^MA DT ^Ph , MM ^A DT ^Ph , M ^MA Q, M ^{A Q} , MM ^MA Q, MMA Q, M ^Vi M ^MA Q, M ^Vi M ^A Q, M ^MA DQ, M ^A DQ, MM ^MA DQ, MM ^A DQ, M ^Vi M ^MA DQ, ^{MViMA DQ}

The branched organopolysiloxanes represented by the above formulas (1) and (2) can be used as component (B) singly or in any combination of two or more.

Particularly preferred components (B) are MT ^MA , ^MTA , MDT ^MA , MDT ^A , MD ^{MAT Ph} , MD ^{ATP Ph} , MD ^{Hex DMA} T ^Ph , MD ^{Hex DA} T ^Ph , MD ^{MAT Ph} , It is one compound or a combination of two or more compounds selected from the group consisting of branched organopolysiloxanes having a combination of siloxy units represented by ^MDATPh , ^{MMMAQ ,} and ^MMAAQ . Among them, branched polysiloxanes represented by MD ^Hex D ^{MAT Ph} , MD ^Hex D ^{ATP Ph} , MD ^{MAT Ph} , MD ^{ATP Ph} , MM ^MA Q, and MM ^A Q are particularly preferably used. The content of each siloxy unit (in particular, the values of c, d, e, and f corresponding to each unit), the viscosity and the number of silicon atoms contained in the branched organopolysiloxane composed of these structural units are the same as the average unit It is the same as the branched organopolysiloxane represented by formula (2).

[Mixing ratio of component (A)/(B)]
The mixing ratio of component (A) and component (B) is such that the total amount of component (A) and component (B) is 100% by mass, the ratio of component (A) is 5 to 95% by mass, and the ratio of component (B) is is 95 to 5% by mass. When the proportions of components (A) and (B) are within this range, the viscosity of the curable composition is adjusted appropriately, good high-energy ray curability is maintained, and the mechanical properties of the obtained cured product, particularly storage elasticity. A material with a large modulus can be designed. By increasing the ratio of component (A), it is easy to design a cured product having a high hardness. On the other hand, by increasing the ratio of the component (B), it is easy to design the cured product to have a low dielectric constant. A preferable proportion of component (A) is 30% by mass or more and 85% by mass or less, more preferably 35% by mass or more and 80% by mass or less, and still more preferably 40% by mass of the total amount of components (A) and (B). Above, it is below 80 mass %.

[No use of organic solvents]
The high-energy ray-curable composition of the present invention can achieve a viscosity suitable for a coating agent without substantially using an organic solvent by using each of the components described above. It does not contain solvents. As used herein, substantially free of organic solvent means that the content of organic solvent is less than 0.1% by mass of the entire composition, and is preferably analyzed using an analytical method such as gas chromatography. It means that it is below the limit. In the present invention, a desired viscosity can be achieved without using an organic solvent by adjusting the molecular structure and molecular weight of component (A) and component (B).

If desired, a photopolymerization initiator can be added to the high-energy ray-curable composition of the present invention in addition to the above components (A) and (B). A photoradical polymerization initiator can be used as the photopolymerization initiator. The photo-radical polymerization initiator can cure the composition of the present invention by generating free radicals upon irradiation with ultraviolet rays or electron beams, which induce radical polymerization reactions. A polymerization initiator is usually unnecessary when the composition of the present invention is cured by electron beam irradiation.

Radical photopolymerization initiators are roughly classified into photocleavage type and hydrogen abstraction type, but the photoradical polymerization initiator used in the composition of the present invention is arbitrarily selected from those known in the art. It can be selected and used, and is not particularly limited. Some photoradical polymerization initiators can accelerate the curing reaction not only under irradiation with high-energy rays such as ultraviolet rays but also under light irradiation in the visible light range.

Specific examples of radical photopolymerization initiators include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2 α-ketol compounds such as hydroxypropiophenone and 1-hydroxycyclohexylphenyl ketone; methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4 Acetophenone compounds such as -(methylthio)-phenyl]-2-morpholinopropane-1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether; ketal compounds such as benzyl dimethyl ketal; aromatic sulfonyl chloride compounds such as naphthalenesulfonyl chloride; photoactive oxime compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; benzophenone, benzoylbenzoic acid, 3,3' -benzophenone compounds such as dimethyl-4-methoxybenzophenone; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone , 2,4-diethylthioxanthone and 2,4-diisopropylthioxanthone; camphorquinone; and halogenated ketones. 

Similarly, bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide are suitable photoradical polymerization initiators in the present invention. , bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4 ,4-trimethylpentylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-( Bisacylphosphine oxides such as 2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide and bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; 2,6-dimethoxybenzoyl diphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, monoacylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2- anthraquinones such as amyl anthraquinone and 2-aminoanthraquinone; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate and p-dimethylbenzoic acid ethyl ester; bis(η5-2,4) -cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3- (2-(1-Pyr-1-yl)ethyl)phenyl]titanium and other titanocenes; phenyl disulfide 2-nitrofluorene, butyroin, anisoine ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide can be mentioned.

Suitable commercial products of the acetophenone-based photopolymerization initiator in the present invention include Omnirad 907, 369, 369E, 379 manufactured by IGM Resins. Commercially available acylphosphine oxide-based photopolymerization initiators include Omnirad TPO, TPO-L, and 819 manufactured by IGM Resins. Commercially available oxime ester photopolymerization initiators include Irgacure OXE01, OXE02, OXE03, OXE04 manufactured by BASF Japan Ltd., N-1919 manufactured by ADEKA Co., Ltd., Adeka Arcles NCI-831, NCI-831E, and Changzhou Strong Denshi. Examples include TR-PBG-304 manufactured by Shinzai Co., Ltd.

The amount of the radical photopolymerization initiator to be added to the composition of the present invention is not particularly limited as long as the desired photopolymerization reaction or photocuring reaction occurs. It is used in an amount of 0.01 to 5% by weight, preferably 0.05 to 3% by weight.

A photosensitizer can also be used in combination with the photoradical polymerization initiator. The use of a sensitizer can increase the photon efficiency of the polymerization reaction, making longer wavelength light available for the polymerization reaction compared to the use of the photoinitiator alone. It is known to be particularly effective when the coating thickness is relatively thick or when relatively long wavelength LED light sources are used. Sensitizers include anthracene compounds, phenothiazine compounds, perylene compounds, cyanine compounds, merocyanine compounds, coumarin compounds, benzylidene ketone compounds, (thio)xanthene or (thio)xanthone compounds such as isopropyl Thioxanthone, 2,4-diethylthioxanthone, alkyl-substituted anthracenes, squarium-based compounds, (thia)pyrylium-based compounds, porphyrin-based compounds, etc. are known, and any photosensitizer may be used in the curing of the present invention without being limited to these. can be used in sexual compositions.

The cured product obtained from the curable composition of the present invention can be cured according to the molecular chain length, molecular structure, and number of (meth)acryloxy groups per molecule of component (A) and component (B). The physical properties of the product and the curing rate of the curable composition can be obtained, and the viscosity of the curable composition can be designed to a desired value. A cured product obtained by curing the curable composition of the present invention is also included in the scope of the present invention. Furthermore, the shape of the cured product obtained from the composition of the present invention is not particularly limited, and may be a thin coating layer, a molded product such as a sheet, or a specific site in an uncured state. It may be injected into and cured to form a filling, or may be used as a sealing material or an intermediate layer for laminates, display devices, or the like. The cured product obtained from the composition of the present invention is preferably in the form of injection-molded protective/adhesive layers and thin-film coating layers, particularly preferably thin-film insulating coating layers.

The curable composition of the present invention is suitable for use as a coating agent or potting agent, particularly as an insulating coating agent or potting agent for electronic devices and electrical devices.

The cured product obtained by curing the curable composition of the present invention has mechanical properties, specifically, high elastic modulus and low dielectric constant. When the relative dielectric constant at room temperature and 100 kHz is measured by the capacitance method, it usually has a value of 3.0 or less. By optimizing the curable composition, it is possible to make the dielectric constant of the cured product 2.6 or less, which is useful as an insulating layer material for flexible displays.

When the curable composition of the present invention is used as an injection molding material and coating agent, an E-type viscometer is used in order to provide suitable fluidity and workability for applying the composition to a substrate. The viscosity of the composition as a whole is 100 mPa·s or less at 25°C. When used as an injection molding material, the viscosity is preferably 80 mPa·s or less, depending on the injection gap. On the other hand, when used as a coating agent, considering the application of the inkjet printing method, which is rapidly being put into practical use, the preferable viscosity range is 5 to 60 mPa s, more preferably 5 to 30 mPa s, and particularly preferably 5 to 20 mPa. · s. In order to adjust the viscosity of the entire curable composition to a desired viscosity, compounds having preferable viscosities can be used as respective components so that the viscosity of the entire composition has the desired viscosity.

[Component (C)]
When the high-energy ray-curable composition of the present invention is applied as a coating agent to the substrate surface using any method, the wettability of the composition to the substrate is improved to form a defect-free coating film. In order to achieve this, a component (C) selected from the following can be further added to the composition of the present invention containing the components described above. It is particularly preferred to use an inkjet printing method as a method for coating a substrate with the composition of the invention. Accordingly, component (C) is a component that improves the wettability of the high-energy ray-curable composition of the present invention to substrates, and particularly significantly improves ink-jet printing properties. Component (C) is at least one compound selected from the group consisting of (C1), (C2) and (C3) below.

(i) Component (C1)
Component (C1) is a silicon-free non-acrylic non-ionic surfactant, ie a non-acrylic non-ionic surfactant. A non-acrylic surfactant means that the surfactant does not have a (meth)acrylate group in its molecule. Surfactants that can be used as component (C1) include organic nonionic surfactants such as glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, alkyl glycosides, and acetylene glycol polyethers. Active agents, fluorine-based nonionic surfactants, and the like can be mentioned, and these can be used singly or in combination of two or more. Specific examples of the component (C1) include, as organic nonionic surfactants, Emulgen series and Rheodor series manufactured by Kao Corporation, Surfynol 400 series manufactured by Evonik Industries, and Olphine E series manufactured by Nissin Chemical Industry Co., Ltd. Fluorinated nonionic surfactants include FC-4400 series manufactured by 3M and Megafac 550 and 560 series manufactured by DIC Corporation.
Among these, Surfynol 400 series and Olphine E series, which are alkynol polyethers, are particularly preferred.

(ii) Component (C2) is a nonionic surfactant containing a silicon atom and having an HLB value of 4 or less. Here, the HLB value is a value that represents the degree of affinity of a surfactant for water and an organic compound. /molecular weight) is used. Silicone polyethers having polyethers as hydrophilic moieties, glycerol silicones having (di)glycerol derivatives as hydrophilic moieties, and carbinol silicones having hydroxyethoxy groups as hydrophilic moieties are known as silicon-containing nonionic surfactants. . Among these surfactants, those with an HLB value of 4 or less, that is, those with a hydrophilic moiety mass fraction of 20% by mass or less, are preferably used in the composition of the present invention. Among these, carbinol silicone is particularly preferred.

(iii) Component (C3) is a silicone oil having a viscosity of 90 mPa·s or less at 25°C. Examples of silicone oils include both-terminated trimethylsilyl-polydimethylsiloxane, both-terminated dimethylvinylsilyl-polydimethylsiloxane, both-terminated trimethylsilyl-dimethylsiloxy/methylvinylsiloxy copolymer, both-terminated dimethylvinylsilyl-dimethylsiloxy/methylvinylsiloxy copolymer. Polymer, Both-Terminal Trimethylsilyl-Dimethylsiloxy/Methylphenylsiloxy Copolymer, Both-Terminal Trimethylsilyl-Dimethylsiloxy/Diphenylsiloxy Copolymer, Both-Terminal Dimethylvinylsilyl-Dimethylsiloxy/Methylphenylsiloxy Copolymer, Both-Terminal Dimethylvinyl Examples thereof include silyl-dimethylsiloxy/diphenylsiloxy copolymers, and preferably both-terminated trimethylsilyl-polydimethylsiloxane and both-terminated dimethylvinylsilyl-polydimethylsiloxane. A preferable viscosity range of the silicone oil is 2 to 50 mPa·s, a more preferable range is 2 to 30 mPa·s, and a further preferable viscosity range is 5 to 20 mPa·s. In addition, the value of the viscosity here is the value measured at 25° C. using the rotational viscometer described in the Examples.

The above-mentioned components (C1) to (C3) can use one or a combination of two or more thereof. The amount of component (C) to be added to the curable composition is not particularly limited. The total of (C3) (collectively referred to as component (C)) is preferably 0.05% by mass or more and 1% by mass or less. When the amount of component (C) is less than 0.05% by mass with respect to 100% by mass of the total amount of components (A) and (B), the effect of improving the wettability of the curable composition to the substrate is obtained. If the amount of component (C) exceeds 1% by mass with respect to the total amount of 100% by mass of components (A) and (B), component (C) will be removed from the cured product after curing. This is because there is a risk that the bleed-out of the

As the component (C), the silicone oil of the component (C3) can be used alone, or the component (C3) can be used in combination with one or more components selected from the group consisting of the component (C1) and the component (C2). It is particularly preferred to use component (C3) alone as component (C).

<Other additives>
In addition to the above ingredients, further additives may be added to the compositions of the present invention as desired. Examples of additives include, but are not limited to, the following.

[Adhesion imparting agent]
Adhesion promoters can be added to the composition of the present invention to improve adhesion and adhesion to substrates in contact with the composition. When the curable composition of the present invention is used as a coating agent, a sealant, etc., where adhesiveness or adhesion to substrates is required, an adhesion-imparting agent may be added to the curable composition of the present invention. is preferred. Any known adhesion promoter can be used as the adhesion promoter as long as it does not inhibit the curing reaction of the composition of the present invention.

Examples of adhesion promoters that can be used in the present invention include trialkoxysiloxy groups (e.g., trimethoxysiloxy group, triethoxysiloxy group) or trialkoxysilylalkyl groups (e.g., trimethoxysilylethyl group, triethoxysilylethyl group) and a hydrosilyl group or an alkenyl group (e.g., vinyl group, allyl group), or an organosiloxane oligomer having a linear, branched or cyclic structure with about 4 to 20 silicon atoms; trialkoxy Organosilanes having a siloxy group or a trialkoxysilylalkyl group and a methacryloxyalkyl group (e.g., 3-methacryloxypropyl group), or organosilanes having a linear, branched or cyclic structure having about 4 to 20 silicon atoms Siloxane oligomer; trialkoxysiloxy group or trialkoxysilylalkyl group and epoxy group-bonded alkyl group (e.g., 3-glycidoxypropyl group, 4-glycidoxybutyl group, 2-(3,4-epoxycyclohexyl)ethyl group) , 3-(3,4-Epoxycyclohexyl)propyl group) or an organosiloxane oligomer having a linear, branched or cyclic structure having about 4 to 20 silicon atoms; a trialkoxysilyl group (e.g., trimethoxysilyl group, triethoxysilyl group); reaction products of aminoalkyltrialkoxysilane and epoxy group-bonded alkyltrialkoxysilane; epoxy group-containing ethyl polysilicate; vinyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, hydrogentriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 1,6-bis(trimethoxysilyl)hexane, 1,6-bis(triethoxysilyl)hexane, 1,3 -bis[2-(trimethoxysilyl)ethyl]-1,1,3,3-tetramethyldisiloxane, reaction product of 3-glycidoxypropyltriethoxysilane and 3-aminopropyltriethoxysilane, silanol group capping Methylvinylsiloxane oligomer and 3-glycidoxypropyl A condensation reaction product of trimethoxysilane, a condensation reaction product of a silanol group-blocked methylvinylsiloxane oligomer and 3-methacryloxypropyltriethoxysilane, and tris(3-trimethoxysilylpropyl)isocyanurate can be mentioned.

The amount of the adhesion promoter added to the curable composition of the present invention is not particularly limited. It is preferably in the range of 0.01 to 5 parts by mass, or preferably in the range of 0.01 to 2 parts by mass.

[Further Optional Additives]
If desired, other additives may be added to the composition of the present invention in addition to or instead of the adhesion imparting agent described above. Additives that can be used include leveling agents, silane coupling agents that are not included in the adhesiveness imparting agents described above, ultraviolet absorbers, antioxidants, polymerization inhibitors, fillers (reinforcing fillers, insulating and functional fillers such as thermally conductive fillers). Suitable additives can be added to the composition of the present invention, if desired. Further, a thixotropic agent may be added to the composition of the present invention as necessary, particularly when used as a potting agent or sealing material.

[Use]
The high-energy ray-curable composition of the present invention can be cured not only by ultraviolet rays but also by electron beams, which is also an aspect of the present invention.

By irradiating the composition of the present invention with high-energy rays such as ultraviolet rays, a radical polymerization reaction proceeds and a cured product can be formed.

Usable high-energy rays include ultraviolet rays, gamma rays, X-rays, α-rays, electron beams, and the like. In particular, ultraviolet rays, X-rays, and electron beams emitted from a commercially available electron beam irradiation device can be mentioned. It is preferable from the viewpoint of industrial use. In addition, although the irradiation dose differs depending on the type of the high-energy ray-activating catalyst, in the case of ultraviolet rays, the cumulative irradiation dose at a wavelength of 365 nm is preferably within the range of 100 mJ/cm ² to 10 J/cm ² .

The curable composition of the present invention has a low viscosity and is particularly useful as a material for forming insulating layers that constitute various articles, especially electronic devices and electrical devices. The composition of the present invention is coated on a substrate, or sandwiched between two substrates, at least one of which is made of a material that transmits ultraviolet rays or electron beams, and is irradiated with ultraviolet rays or electron beams. The material can be cured to form an insulating layer. In that case, the composition of the present invention can be patterned when applied to a substrate and then cured, or the composition can be applied to a substrate and cured with UV or electron beam radiation. It is also possible to form an insulating layer having a desired pattern by leaving a cured portion and an uncured portion by irradiation of , and then removing the uncured portion with a solvent. In particular, if the stiffening layer according to the present invention is an insulating layer, it can be designed to have a low dielectric constant of less than 3.0.

The curable composition of the present invention is particularly suitable as a material for forming insulating layers of display devices such as touch panels and displays because the cured product obtained therefrom has good transparency. In this case, the insulating layer may form any desired pattern, as described above, if desired. Accordingly, a display device such as a touch panel and a display including an insulating layer obtained by curing the high-energy ray-curable organopolysiloxane composition of the present invention is also an aspect of the present invention.

In addition, the curable composition of the present invention can be used to coat an article and then cured to form an insulating coating layer (insulating film). Therefore, the composition of the present invention can be used as an insulating coating agent. A cured product formed by curing the curable composition of the present invention can also be used as an insulating coating layer.

The insulating film formed from the curable composition of the present invention can be used for various purposes. In particular, it can be used as a component of electronic devices or as a material used in the process of manufacturing electronic devices. Electronic devices include electronic equipment such as semiconductor devices and magnetic recording heads. For example, the curable composition of the present invention can be used for semiconductor devices such as LSI, system LSI, DRAM, SDRAM, RDRAM, D-RDRAM, insulating films for multi-chip module multilayer wiring boards, interlayer insulating films for semiconductors, and etching stopper films. , a surface protective film, a buffer coat film, a passivation film in LSI, a cover coat for flexible copper-clad plates, a solder resist film, and a surface protective film for optical devices.

In addition to being used as a coating agent, the high-energy ray-curable composition of the present invention is suitable for use as a potting agent, particularly an insulating potting agent for electronic devices and electrical devices.

The composition of the present invention can be used as a material for forming a coating layer on a substrate surface, especially using an inkjet printing method, in which case the composition of the present invention contains component (C) as described above. is particularly preferred.

The present invention will be further described based on examples below, but the present invention is not limited to the following examples.

The high-energy ray-curable composition of the present invention and its cured product will be described in detail with reference to examples. Measurements and evaluations in Examples and Comparative Examples were carried out as follows.

[Viscosity of curable composition]
The viscosity (mPa·s) of the composition at 25° C. was measured using a rotational viscometer (E-type viscometer VISCONIC EMD manufactured by Tokimec Co., Ltd.).

[Appearance of curable composition and cured product obtained therefrom]
The appearance of the curable composition and the cured product with a thickness of 0.1 mm obtained therefrom was visually observed and evaluated.

[Preparation of curable composition]
The amounts of each material shown in Table 1 below were placed in a brown plastic container and well mixed using a planetary mixer to prepare a curable composition.

[Wettability of curable composition to substrate (contact angle of composition)]
2 microliters of the curable composition was dropped on a silicon nitride-coated glass substrate, and the contact angle (unit: °) of the curable composition immediately after dropping and after 15 seconds had passed was measured using a contact angle measuring device manufactured by Kyowa Interface Science Co., Ltd. Measured at 23°C with DM-700.

[Curing of curable composition and preparation of dynamic viscoelastic test piece]
About 0.55 g of the curable composition was injected between two glass substrates sandwiching a 1.0 mm thick spacer. By irradiating LED light with a wavelength of 405 nm with an energy amount of 2 J/cm ² through one of the glass substrates from the outside, the composition is cured to form a strip of 10 × 50 × 1.0 (thickness) mm ³ A test piece was prepared.

[Viscoelasticity measurement of cured organopolysiloxane]
Using a strip-shaped test piece prepared from the organopolysiloxane cured product, a frequency of 1 Hz, a strain of 0.1%, a stress of -0.1 N/mm2, and a temperature increase were performed using a dynamic viscoelasticity measuring device MCR-302 manufactured by Anton Paar. Viscoelasticity measurement was performed in the temperature range from -40°C to 160°C at a rate of 3°C/min, and the storage modulus value (unit: Pa) at 130°C was recorded.

[Curing of curable composition and preparation of sample for dielectric constant measurement]
A mold with a thickness of 1 mm and having a circular hole with an inner diameter of 40 mm was placed on the PET film coated with the fluoropolymer release agent, and about 1.3 g of the curable composition was poured into the hole. The composition was covered with the same PET film as above, and a glass plate with a thickness of 10 mm was placed thereon. The composition was cured by irradiating LED light having a wavelength of 405 nm with an energy amount of 2 J/cm ² from above to prepare a disk-shaped cured organopolysiloxane having a diameter of 40 mm and a thickness of 1 mm.

[Dielectric constant of cured organopolysiloxane]
A tin foil having a diameter of 33 mm and a thickness of 0.007 mm was crimped onto both surfaces of the prepared organopolysiloxane cured product. In order to improve the adhesiveness between the cured product and the foil, they were pressure-bonded via a very small amount of silicone oil, if necessary. The capacitance was measured at room temperature and 100 KHz with an E4990A precision impedance analyzer manufactured by Keysight Technologies, to which parallel plate electrodes with a diameter of 30 mm were connected. The dielectric constant was calculated using the thickness of the cured product and the value of the electrode area.

[Stability of cured organopolysiloxane]
A cured product thin film having a thickness of 10 μm was prepared on a glass substrate coated with ITO by a spin coating method followed by ultraviolet irradiation (LED light with a wavelength of 405 nm and an energy amount of 2 J/cm ² ). A silver thin film (thickness: about 20 nanometers) was vapor-deposited on this cured product by plasma CVD with the substrate temperature set to 80° C. under vacuum. Changes in the surface of the cured product at that time were visually observed and evaluated according to the following criteria.
A: The surface is smooth and almost unchanged. B: Wrinkles are observed on the surface or the surface is slightly discolored to black. C: Many wrinkles are observed on the surface and most of the surface is discolored to black.

[Examples and Comparative Examples]
A high-energy ray-curable composition having the composition (parts by mass) shown in Table 1 was prepared using the following components. M in the B component is Me ₃ SiO _1/2 units, D ^Hex is Me(CH ₂ =CH(CH ₂ ) ₄ )SiO _2/2 units, D ^MA1 is Me(CH ₂ =C(CH ₃ ) _CO2 ( _CH2 ) _3SiMe2OSiMe2 ( _CH2 ) ₆ )SiO2 _/2 units, ^DMA2 is Me( _CH2 = _C ( _{CH3 ) CO2} ( _CH2 ) ₃ )SiO2 _/2 The unit T ^Ph _stands for _{C6H5SiO3 /2} units.
(A1) Isobornyl acrylate (A2) Tricyclodecanedimethanol diacrylate (B1) Branched polysiloxane represented by M _0.2 D ^Hex _0.33 D ^MA1 _0.07 T ^Ph _0.4 (methacrylate group Average number of: 1.0)
(B2) Branched polysiloxane represented by M _0.2 D ^Hex _0.28 D ^MA1 _0.12 T ^Ph _0.4 (average number of methacrylate groups: 1.6)
(B3) Branched polysiloxane represented by M _0.2 D ^Hex _0.41 D ^MA1 _0.19 T ^Ph _0.2 (average number of methacrylate groups: 2.4)
(B4) Branched polysiloxane represented by M _0.2 D ^MA2 _0.33 T ^Ph _0.47 (average number of methacrylate groups: 2.8)
(b') branched polysiloxane represented by M _0.2 D ^Hex _0.6 T ^Ph _0.2 (not including methacrylate groups)
(C) Polydimethylsiloxane end-blocked with trimethylsiloxy groups (product name: DOWSIL (TM) SH 200 Fluid (viscosity at 25°C: 20 mPa s), manufactured by Dow Silicones Corporation)
(D) 2,4,6-trimethylbenzoyldiphenylphosphine oxide (product name Omnirad TPO, manufactured by IGM Resins)
(E) dibutyl hydroxytoluene (polymerization inhibitor)

The contact angles of the composition of Example 4 immediately after dropping and 15 seconds after dropping were 16° and 10°, respectively. On the other hand, the contact angles of the composition of Example 5 immediately after dropping and 15 seconds after dropping were 14° and <1°, respectively.

As shown in Table 1, the high-energy radiation curable compositions of the present invention (Examples 1-6) are suitable as injection molding materials and as coating agents for application to substrates, particularly by inkjet printing. It has viscosity and high transparency. Moreover, the present composition has good wettability with respect to the substrate, and the wettability can be further improved by adding the component (C) (Example 5). Furthermore, the cured product obtained from the composition of the present invention has a high elastic modulus and is excellent in stability at high temperatures. In particular, the compositions in Examples 3, 4, and 6 exhibited extremely good stability at high temperatures. Also, the cured product obtained from the composition of the invention exhibits low dielectric properties. On the other hand, in the composition (comparative example) using branched polysiloxane (b') that does not contain (meth)acryloxy groups in the component molecule instead of component (B), the stability of the cured product at high temperatures It was inferior in quality, and coloration and many wrinkles were observed.

The high-energy ray-curable composition of the present invention is suitable for the above-mentioned uses, particularly as a material for forming an insulating layer of display devices such as touch panels and displays, especially flexible displays.

Claims (14)

(A) 5 to 95 parts by mass of a compound having one or more (meth)acryloxy groups in one molecule and having no silicon atoms, and (B) one or more (meth)acryloxy groups in one molecule A composition containing 95 to 5 parts by mass of a branched organopolysiloxane having no alkoxy groups, substantially free of organic solvents, and measured at 25°C using an E-type viscometer A high-energy ray-curable composition, characterized in that the viscosity of the entire product is 100 mPa·s or less. Component (A) is a compound having one (meth)acryloxy group and no silicon atom or a mixture of two or more compounds having one (meth)acryloxy group and no silicon atom; The high-energy ray-curable composition according to claim 1. Component (A) is a mixture of one or more compounds having one (meth)acryloxy group and no silicon atoms and one or more compounds having two or more (meth)acryloxy groups and no silicon atoms. The high-energy ray-curable composition according to claim 1 or 2, which is The ultraviolet-curable composition according to any one of claims 1 to 3, wherein component (A) contains a compound having one or more acryloxy groups in one molecule and no silicon atoms. The ultraviolet-curable composition according to claim 1, wherein component (A) is a compound having one (meth)acryloxy group in one molecule and no silicon atoms. Component (B) has the average compositional formula:
R _a R′ _b SiO _(4-ab)/2 (1)
(Wherein, R is a (meth) acryloxy group-containing group,
R′ is a group selected from unsubstituted or fluorine-substituted monovalent hydrocarbon groups and hydroxyl groups, and a and b satisfy the following conditions: 1≦a+b<3 and 0.01≦a/(a+b)< A number that satisfies 1.0 and has at least one R in the molecule. )
The high-energy ray-curable composition according to any one of claims 1 to 5, which is a branched organopolysiloxane represented by Component (B) has the average unit formula:
(X ₃ SiO _1/2 ) _c (X ₂ SiO _2/2 ) _d (XSiO _3/2 ) _e (SiO _4/2 ) _f (2)
(Wherein, X is each independently a group selected from (meth)acryloxy group-containing groups, unsubstituted or fluorine-substituted monovalent hydrocarbon groups, and hydroxyl groups, and among all X, at least one is a (meth)acryloxy group-containing group, (e + f) is a positive number, c is 0 or a positive number, and d is a number within the range of 0 to 100). The high-energy ray-curable composition according to any one of claims 1 to 6, which is polysiloxane. The high-energy ray-curable composition according to any one of claims 1 to 7, wherein component (B) is a branched organopolysiloxane further having one or more alkenyl groups in its molecule. High energy according to any one of claims 1 to 8, wherein component (B) is a branched organopolysiloxane having two or more (meth)acryloxy groups in one molecule and no alkoxy groups. A radiation-curable composition. The high-energy ray-curable composition according to any one of claims 1 to 9, wherein the viscosity of the entire composition measured at 25°C using an E-type viscometer is in the range of 5 to 30 mPa·s. An insulating coating agent comprising the high-energy ray-curable composition according to any one of claims 1 to 10. A cured product of the high-energy ray-curable composition according to any one of claims 1 to 10. A method of using the cured product of the high-energy ray-curable composition according to any one of claims 1 to 10 as an insulating coating layer. A display device comprising a layer comprising a cured product of the high-energy ray-curable composition according to any one of claims 1 to 10.