Ultraviolet-curable organopolysiloxane composition and its uses

Abstract

The present invention provides an ultraviolet-curable organopolysiloxane composition which has excellent workability when applied on a substrate, and whereby a product obtained by curing the ultraviolet-curable organopolysiloxane composition has low relative permittivity. This ultraviolet-curable organopolysiloxane composition is characterized by containing: (A) one or more organosiloxanes and / or organopolysiloxanes having an average of two or more ultraviolet-reactive functional groups in each molecule thereof; and (B) one or more organosilanes, organosiloxanes, and / or organopolysiloxanes having one ultraviolet-reactive functional group in each molecule thereof, and in that the composition does not include an organic solvent. This composition preferably includes, in addition to components (A) and (B), one or a plurality of additives selected from the group consisting of (D1) a nonionic surfactant which does not include a silicon atom and which is not acrylic, (D2) a nonionic surfactant which includes a silicon atom and which has an HLB value of 4 or less, and (D3) silicone oil having a viscosity at 25°C of 90 mPa∙s or less.

Description

[Technical field]

[0001] The present invention relates to an ultraviolet-curable organopolysiloxane composition containing an organosiloxane and / or organopolysiloxane that can be cured by actinic rays, such as ultraviolet rays or electron beams, and in particular to an ultraviolet-curable organopolysiloxane composition having a cured product having a low dielectric constant. The curable organopolysiloxane composition of the present invention has a low dielectric constant of less than 2.8 and is suitable as an insulating material for electronic and electric devices, in particular as a material for use as a coating agent. [Background technology]

[0002] 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 electric devices. Among silicone resins, ultraviolet-curable silicone compositions have also been reported.

[0003] For example, JP 2009-298887 A discloses a curable composition for optical components containing an epoxy-modified silicone and / or an oxetane-modified silicone, a cationic polymerizable monomer, and a cationic polymerization initiator, in which no monofunctional compound containing a silicon atom is exemplified as the cationic polymerizable monomer.

[0004] JP2013-525551A discloses an ultraviolet-curable composition comprising a disiloxane having a cationic polymerizable functional group, a polysiloxane having 9 or more silicon atoms and a cationic polymerizable functional group, an epoxy component and / or an oxetane component not containing a siloxane group, and a cationic photoinitiator.

[0005] In addition, WO 2016 / 167347 discloses a sealant for electronic devices that contains a silicone compound having a UV-reactive group and can be applied by an inkjet method, but does not exemplify a monofunctional compound that has a UV-reactive group and contains a silicon atom.

[0006] Furthermore, JP 2018-111792 A discloses an ultraviolet-curable resin composition containing a polyfunctional cationically polymerizable compound, a monofunctional cationically polymerizable compound having a viscosity of 8 mPa·s or less, and a cationic curing catalyst. As the monofunctional cationically polymerizable compound, no silicon atom-containing compound is exemplified.

[0007] In addition, JP 2020-98684 A describes a composition containing a curable resin containing a low molecular weight silicone compound, a photocationic polymerization initiator, and an acrylic surfactant that does not contain Si atoms, as a cationic polymerization curable inkjet resin composition for sealing organic EL elements, and describes that the use of an acrylic surfactant that does not contain Si improves the initial wetting and spreading properties when applied to a substrate. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2009-298887 A [Patent Document 2] Special Publication No. 2013-525551 [Patent Document 3] International Publication No. 2016 / 167347 [Patent Document 4] JP 2018-111792 A [Patent Document 5] JP 2020-98684 A Summary of the Invention [Problem to be solved by the invention]

[0009] As described above, several ultraviolet-curable organopolysiloxane compositions are known that combine compounds having multiple ultraviolet-reactive functional groups and are used in applications such as materials for electronic devices, but there is still a demand for ultraviolet-curable organopolysiloxane compositions whose cured products have a low relative dielectric constant and excellent workability for application to substrates, particularly low viscosity. The present invention provides an ultraviolet-curable organopolysiloxane composition whose cured product has a low relative dielectric constant and has particularly excellent workability when applied to substrates, and which also has good storage stability at room temperature. [Means for solving the problem]

[0010] The present invention was completed based on the discovery that by controlling the crosslinking structure of organosiloxanes and / or organopolysiloxanes having functional groups that can be cured by irradiation with energy rays that can cause chemical reactions, such as ultraviolet rays or electron beams, it is possible to obtain a cured product that has a low relative dielectric constant, and further, this curable composition has a low viscosity and is excellent in workability when applied to a substrate.

[0011] The present invention relates to an ultraviolet-curable organopolysiloxane composition, which cures through the formation of bonds via ultraviolet-reactive functional groups. However, the curing method is not limited to ultraviolet irradiation, and any method that can cause a curing reaction of the ultraviolet-curable functional groups can be used. For example, the composition of the present invention may be cured using electron beam irradiation.

[0012] The composition of the present invention comprises (A) one or more organosiloxanes and / or organopolysiloxanes having an average of two or more ultraviolet-reactive functional groups per molecule, and (B) one or more organosilanes, organosiloxanes and / or organopolysiloxanes each having one ultraviolet-reactive functional group per molecule; and the composition does not contain any organic solvent.

[0013] In the above composition, the organosiloxane or organopolysiloxane of component (A) has the following average composition formula: R a R’ b SiO (4-a―b) / 2 (1) (In the formula, R is an ultraviolet-reactive functional group, R’ is a group other than the above ultraviolet-curable functional group, selected from a monovalent hydrocarbon group, a hydroxyl group, and an alkoxy group, a and b are numbers satisfying the following conditions: 1 ≦ a + b ≦ 3 and 0.01 ≦ a / (a + b) ≦ 0.34, and having at least two Rs in the molecule.) It is preferably a linear, branched, or cyclic organopolysiloxane represented by Further, the organosilane, organosiloxane, and / or organopolysiloxane of component (B) has the following average composition formula: R c R’ d SiO (4-c―d) / 2 (2) (In the formula, R and R‘ are the same groups as described above, c and d are numbers satisfying the following conditions: 1 < c + d ≦ 4 and 0.05 ≦ c / (c + d) ≦ 0.25, and the number of Rs in the molecule is 1.) It is preferably an organosilane or a linear, branched, or cyclic organopolysiloxane represented by

[0014] Alternatively, in the above composition, the organosiloxane or organopolysiloxane of component (A) has the following formula (3):

Chemical formula

[0015] The organosilane, organosiloxane and / or organopolysiloxane of component (B) is represented by the following formula (3'): [ka] (Wherein, all R 1 ~R 8 Of the R groups, only one UV-reactive functional group is present in the molecule; 1 From R 8 each independently represents an unsubstituted or fluorine-substituted monovalent hydrocarbon group; n is a value that provides a viscosity of 1 to 100 mPa s at 25°C of the (poly)organosiloxane represented by formula (3'), and n may be 0; or The following formula (5): [ka] (wherein each R is independently a group selected from an ultraviolet-reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, and x is an integer of 3 to 10, and has only one ultraviolet-reactive functional group per molecule), Or, the following formula (6): RSiR'3(6) (wherein R is an ultraviolet-reactive functional group, and R' is a group selected from a monovalent hydrocarbon group, a hydroxyl group, and an alkoxy group other than the ultraviolet-reactive functional group), is preferably a silicon-containing compound having one ultraviolet-reactive functional group in the molecule.

[0016] The ultraviolet-reactive functional group is preferably a cationically polymerizable functional group, and the cationically polymerizable functional group is preferably an epoxy group-containing group.

[0017] In the above component (A), the number of ultraviolet-reactive functional groups in component (A) is preferably 2 to 4 on average per molecule.

[0018] In the above component (A), the ultraviolet-reactive functional group of component (A) is preferably an epoxy group-containing group. In the above component (B), the ultraviolet-reactive functional group of component (B) is preferably an epoxy group-containing group.

[0019] Regarding the above component (B), it is preferable that component (B) is an organosiloxane or organopolysiloxane having one ultraviolet-reactive functional group in the molecule.

[0020] In the above composition, the proportion of component (A) is preferably less than 80% by mass relative to 100% by mass of the total of components (A) and (B).

[0021] In the above composition, the proportion of component (A) is preferably less than 50% by mass relative to 100% by mass of the total of components (A) and (B).

[0022] The composition may further contain (C) a compound having one or more UV-reactive functional groups in one molecule and having no silicon atoms, and it is preferable that the mass ratio of component (C) to the total of components (A), (B), and (C) is less than 50%.

[0023] The component (C) is preferably a compound that has one epoxy group in one molecule and contains no oxetane groups or silicon atoms.

[0024] It is preferable that the composition is substantially free of compounds that contain an oxetane group in the molecule and do not contain silicon atoms.

[0025] The viscosity of the composition measured at 25° C. using an E-type viscometer is preferably 100 mPa·s or less, and more preferably in the range of 5 to 50 mPa.s. Furthermore, the relative dielectric constant of the cured product obtained by curing the composition is preferably less than 2.8.

[0026] The present invention further provides an insulating coating agent comprising the above ultraviolet-curable organopolysiloxane composition.

[0027] The present invention also provides a method for using a cured product formed from the above ultraviolet-curable organopolysiloxane composition as an insulating coating layer.

[0028] The present invention also provides a display device comprising a layer made of a cured product formed from the above ultraviolet-curable organopolysiloxane composition. Effect of the Invention

[0029] The ultraviolet ray-curable organopolysiloxane composition of the present invention has an appropriate viscosity that provides good workability when applied to a substrate, and the cured product obtained from the composition has a low dielectric constant. Therefore, the composition is useful as an article including a low dielectric constant layer, particularly a low dielectric constant material for an electronic device, particularly a material for an insulating layer, and particularly a coating material, in any field in which a material having a low dielectric constant is used. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] The configuration of the present invention will be described in further detail below. The ultraviolet-curable organopolysiloxane composition of the present invention essentially comprises the following components (A) and (B), and may optionally contain a component (C) and a component selected from various additives. One of the features of the ultraviolet-curable organopolysiloxane composition of the present invention is that the cured product obtained from the composition has a low relative dielectric constant. The reason why the relative dielectric constant of the cured product obtained from the composition of the present invention is low is not necessarily clear, but it is presumed that nanoscale pores are introduced into the cured product by controlling the crosslinked structure of the polysiloxane formed by ultraviolet irradiation, which results in a low relative dielectric constant. The ultraviolet-curable organopolysiloxane composition of the present invention is useful as an insulating coating agent, particularly as a coating agent for forming an insulating layer in electronic devices and electric devices, for example, display devices such as touch panels and displays and their components, or semiconductor devices, taking advantage of the low relative dielectric constant and good workability of the cured product.

[0031] In the following description, the viscosity of the compound is a value (unit: mPa s) measured at 25°C using an E-type rotational viscometer. The relative dielectric constant is a value measured at 23°C using a capacitance method (capacitor method). These measurement methods are well known to those skilled in the art.

[0032] [Component (A): Organosiloxane and / or organopolysiloxane having, on average, two or more UV-reactive functional groups per molecule] The organosiloxane or organopolysiloxane having a UV-reactive functional group used as component (A) has an average of two or more UV-reactive functional groups per molecule in the organosiloxane or organopolysiloxane skeleton, and the molecular structure can be any as long as this purpose can be achieved. In general, the organosiloxane or organopolysiloxane of component (A) is The average composition formula is as follows: R a R' b SiO (4-a―b) / 2 (1) (wherein R is an ultraviolet-reactive functional group; R' is a group selected from a monovalent hydrocarbon group, a hydroxyl group, and an alkoxy group, excluding the above ultraviolet-reactive functional groups, a and b are numbers that satisfy the following conditions: 1≦a+b≦3 and 0.01≦a / (a+b)≦0.34. The organopolysiloxane is a linear, branched, or cyclic organopolysiloxane represented by the formula:

[0033] The ultraviolet-reactive functional group represented by R in formula (1) is an organic group that can generate a bond between itself by irradiation with ultraviolet light in the presence or absence of a photoinitiator. Examples of ultraviolet-reactive functional groups include radically polymerizable groups and cationic polymerizable groups. The radically polymerizable group is not particularly limited as long as it is a functional group that can form a new bond, particularly a bond between radically polymerizable groups, by a radical reaction mechanism, and examples of the radically polymerizable group include an acryl group, a methacryl group, a maleimide group, and an organic group containing any of these groups. Specific examples of radically polymerizable groups include acryloxypropyl, methacryloxypropyl, acrylamidepropyl, methacrylamidepropyl, and 3-(N-maleimide)propyl groups. Examples of cationic polymerizable groups include vinyl ether groups, epoxy group-containing groups, and oxetane group-containing groups, such as CH2=CH-O-(CH2)n- (n is an integer of 3 to 20), glycidyloxy-(CH2) n -(n is an integer from 3 to 20), 3,4-epoxycyclohexyl-(CH2) n-(n is an integer of 2 to 20) and the like. The ultraviolet-reactive functional group is preferably one or more epoxy-containing groups. Particularly preferred groups include epoxycyclohexylalkyl groups, particularly 3,4-epoxycyclohexylethyl groups. The linear, branched, or cyclic organopolysiloxane represented by the above average composition formula has at least two ultraviolet-reactive functional groups (R) on average per molecule. The number of ultraviolet-curable groups on average per molecule is preferably 2 to 6, more preferably 2 to 5, and particularly preferably 2 to 4.

[0034] The monovalent hydrocarbon group represented by R' is a monovalent hydrocarbon group, which includes unsubstituted monovalent hydrocarbon groups and monovalent hydrocarbon groups substituted with fluorine. 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. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, pentyl, and octyl groups, with the methyl group 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 phenyl and naphthyl groups. Examples of the monovalent hydrocarbon group substituted with fluorine include 3,3,3-trifluoropropyl and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. Examples of the monovalent hydrocarbon group substituted with fluorine include 3,3,3-trifluoropropyl groups. A preferred example of the monovalent hydrocarbon group substituted with fluorine is a 3,3,3-trifluoropropyl group. By introducing fluorine atoms into the organopolysiloxane of formula (1), it may be possible to further reduce the dielectric constant of the cured product obtained from the composition of the present invention.

[0035] The organosiloxane or organopolysiloxane represented by the above formula (1) preferably has a viscosity at 25° C. of 1 to 10,000 mPa s, more preferably 1 to 2,000 mPa s, and particularly preferably 5 to 1,000 mPa s. The viscosity of the organosiloxane or organopolysiloxane can be adjusted by changing the ratio of a and b in formula (1) and the molecular weight.

[0036] In one preferred embodiment, the organosiloxane or organopolysiloxane of component (A) is The following formula (3): [ka] It is a compound represented by the formula:

[0037] As with the compounds represented by formula (1) above, the organosiloxanes or organopolysiloxanes represented by formula (3) have, on average, two or more UV-reactive functional groups per molecule. 1 ~R 8 Among the groups, two or more per molecule are ultraviolet-reactive functional groups on average. The ultraviolet-reactive functional groups are organic groups that can form bonds between each other by irradiation with ultraviolet light in the presence or absence of a photoinitiator. Examples of ultraviolet-reactive functional groups include radically polymerizable groups and cationic polymerizable groups. The radically polymerizable groups are not particularly limited as long as they are functional groups that can form new bonds, particularly bonds between radically polymerizable groups, by a radical reaction mechanism, and examples of the radically polymerizable groups include an acrylic group, a methacrylic group, a maleimide group, and an organic group containing any of these groups. Specific examples of radically polymerizable groups include groups such as acryloxypropyl, methacryloxypropyl, acrylamidepropyl, methacrylamidepropyl, and 3-(N-maleimide)propyl. Examples of the cationic polymerizable groups include groups such as a vinyl ether group, an epoxy group-containing group, and an oxetane group-containing group, such as CH2=CH-O-(CH2)n- (n is an integer of 3 to 20), and glycidyloxy-(CH2) n-(n is an integer from 3 to 20), 3,4-epoxycyclohexyl-(CH2) n -(n is an integer of 2 to 20) and the like. The ultraviolet-reactive functional group is preferably one or more epoxy-containing groups, and particularly preferably an epoxycyclohexylalkyl group, in particular a 3,4-epoxycyclohexylethyl group.

[0038] In formula (3), R other than the ultraviolet-reactive functional group 1 From R 8 are each independently selected from unsubstituted or fluorine-substituted monovalent hydrocarbon groups, preferably unsubstituted or fluorine-substituted alkyl, cycloalkyl, arylalkyl, and aryl groups having 1 to 20 carbon atoms. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, pentyl, and octyl groups, with methyl 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 phenyl and naphthyl groups. Examples of the fluorine-substituted monovalent hydrocarbon group include 3,3,3-trifluoropropyl and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. Examples of the fluorine-substituted monovalent hydrocarbon group include 3,3,3-trifluoropropyl groups. By introducing fluorine atoms into the organopolysiloxane of formula (3), the relative dielectric constant of the cured product obtained from the composition of the present invention may be further reduced.

[0039] The organosiloxane and / or organopolysiloxane of formula (3) which is component (A) has an average of 2 to 6, preferably 2 to 5, and particularly preferably 2 to 4 ultraviolet-reactive functional groups per molecule as a whole.

[0040] In particular, it is preferred that one of R1 to R3 and one of R6 to R8 in formula (3) is a UV-reactive functional group.Moreover, it is particularly preferred that only one of R1 to R3 and one of R6 to R8 in formula (3) is a UV-reactive functional group.

[0041] The n in formula (3) is preferably a value that gives the organosiloxane or organopolysiloxane represented by formula (3) a viscosity at 25°C of 1 to 10,000 mPa·s, more preferably a value that gives 1 to 2,000 mPa·s, and particularly preferably a value that gives 5 to 1,000 mPa·s. A person skilled in the art can easily determine the value of n so that the viscosity of the organosiloxane or organopolysiloxane of formula (3) falls within the above-mentioned viscosity range without the need for excessive trial and error. However, in general, the number of n is preferably 0 to 500, more preferably in the range of 0 to 100, so that the compound of formula (3) has the desired viscosity.

[0042] The organosiloxane or organopolysiloxane of formula (3) can be used alone or in a mixture of two or more. When two or more organosiloxanes and / or organopolysiloxanes are used as a mixture, the viscosity of the mixture at 25°C is preferably 1 to 10,000 mPa·s, more preferably 1 to 2,000 mPa·s, and particularly preferably 5 to 1,000 mPa·s.

[0043] The compound of formula (1) above may be an organopolysiloxane represented by the following average unit formula (4). Average unit formula: (R3SiO 1 / 2 ) e (R2SiO 2 / 2 ) f (RSiO 3 / 2 ) g (SiO 4 / 2 ) h (4) In formula (4), R is each independently a group selected from an ultraviolet-reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, at least two of all R are ultraviolet-reactive functional groups, (g+h) is a positive number, e is 0 or a positive number, and f is a number within the range of 0 to 100. The UV-reactive functional group and the monovalent hydrocarbon group are as defined above for formula (1), and the preferred viscosity of the organopolysiloxane represented by formula (4) is also as defined above for the organopolysiloxane represented by formula (1). Specific examples of the organosiloxane or organopolysiloxane represented by the above formula (1) include 1,3-bis(3,4-epoxycyclohexylethyl)-1,1,3,3-tetramethyldisiloxane, 1,5-bis(3,4-epoxycyclohexylethyl)-1,1,3,3,5,5-hexamethyltrisiloxane, methyltris(3,4-epoxycyclohexylethyldimethylsiloxy)silane, tetrakis(3,4-epoxycyclohexylethyldimethylsiloxy)silane, both-end(3,4-epoxycyclohexylethyldimethylsilyl)-polydimethylsiloxane, both-end(trimethylsilyl-dimethylsiloxy / (methyl-3,4-epoxycyclohexylethylsiloxy) copolymer, and both-end(3,4-epoxycyclohexylethyldimethylsilyl)-dimethylsiloxy / (methyl-3,4-epoxycyclohexylethylsiloxy) copolymer.

[0044] The organosiloxane or organopolysiloxane represented by the above formula (3) and the organopolysiloxane represented by the above formula (4) can each be used alone or in any combination of two or more. That is, the organosiloxane or organopolysiloxane represented by formula (3), the organopolysiloxane represented by formula (4), and a mixture of two or more selected from them can be used as component (A) of the composition of the present invention.

[0045] [Component (B): Organosilane, organosiloxane, and / or organopolysiloxane having one UV-reactive functional group per molecule] Component (B) is an organosilane, organosiloxane, or organopolysiloxane skeleton having one UV-reactive functional group per molecule, and has the effect of controlling the crosslink density of the cured product obtained from the composition of the present invention, lowering the dielectric constant, and at the same time, reducing the viscosity of the composition. As long as this purpose can be achieved, the molecular structure can be any. In general, the organosilane, organosiloxane, and / or organopolysiloxane of component (B) are: The average composition formula is as follows: R c R' d SiO (4-c―d) / 2 (2) (In the formula, R is an ultraviolet-curable functional group, R' is a group selected from a monovalent hydrocarbon group, a hydroxyl group, and an alkoxy group, excluding the above ultraviolet-curable functional groups, c and d are numbers that satisfy the following conditions: 1≦c+d≦3 and 0.05≦c / (c+d)≦0.25. Also, the number of R in the numerator is 1. or a linear, branched, or cyclic organopolysiloxane.

[0046] The ultraviolet-reactive functional group represented by R in formula (2) is an organic group that can generate a bond between itself by irradiation with ultraviolet light in the presence or absence of a photoinitiator. Examples of ultraviolet-reactive functional groups include radically polymerizable groups and cationic polymerizable groups. The radically polymerizable group is not particularly limited as long as it is a functional group that can form a new bond, particularly a bond between radically polymerizable groups, by a radical reaction mechanism, and examples of the radically polymerizable group include an acryl group, a methacryl group, a maleimide group, and an organic group containing any of these groups. Specific examples of radically polymerizable groups include acryloxypropyl, methacryloxypropyl, acrylamidepropyl, methacrylamidepropyl, and 3-(N-maleimide)propyl groups. Examples of cationic polymerizable groups include vinyl ether groups, epoxy group-containing groups, and oxetane group-containing groups, such as CH2=CH-O-(CH2)n- (n is an integer of 3 to 20), glycidyloxy-(CH2) n -(n is an integer from 3 to 20), 3,4-epoxycyclohexyl-(CH2) n -(n is an integer of 2 to 20) and the like. The ultraviolet-reactive functional group is preferably one or more epoxy-containing groups. Particularly preferred groups include epoxycyclohexylalkyl groups, particularly 3,4-epoxycyclohexylethyl groups. The organosilane or linear, branched, or cyclic organopolysiloxane represented by the above average composition formula has one ultraviolet-reactive functional group (R) per molecule.

[0047] The monovalent hydrocarbon group represented by R' is a monovalent hydrocarbon group, which includes unsubstituted monovalent hydrocarbon groups and monovalent hydrocarbon groups substituted with fluorine. 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. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, pentyl, and octyl groups, with the methyl group 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 phenyl and naphthyl groups. Examples of the monovalent hydrocarbon group substituted with fluorine include 3,3,3-trifluoropropyl and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. Examples of the monovalent hydrocarbon group substituted with fluorine include 3,3,3-trifluoropropyl groups. A preferred example of the monovalent hydrocarbon group substituted with fluorine is a 3,3,3-trifluoropropyl group. By introducing fluorine atoms into the organopolysiloxane of formula (2), it may be possible to further reduce the dielectric constant of the cured product obtained from the composition of the present invention.

[0048] The organosilane, organosiloxane, or organopolysiloxane represented by the above formula (2) preferably has a viscosity at 25° C. of 1 to 500 mPa s, more preferably 1 to 100 mPa s, and particularly preferably 5 to 50 mPa s. The viscosity of the organosiloxane or organopolysiloxane can be adjusted by changing the ratio of c and d in formula (2) and the molecular weight.

[0049] In one preferred embodiment, the organosilane, or organosiloxane or organopolysiloxane of component (B) is The following formula (3'): [ka] The organosiloxane or organopolysiloxane compound is represented by the formula:

[0050] As with the compound represented by formula (2) above, the ultraviolet-reactive functional groups are organic groups that can form bonds between each other by irradiation with ultraviolet light in the presence or absence of a photoinitiator. Examples of ultraviolet-curable functional groups include radically polymerizable groups and cationic polymerizable groups. The radically polymerizable group is not particularly limited as long as it is a functional group that can form a new bond, particularly a bond between radically polymerizable groups, by a radical reaction mechanism, and examples of the radically polymerizable group include an acrylic group, a methacrylic group, a maleimide group, and an organic group containing any of these groups. Specific examples of radically polymerizable groups include groups such as acryloxypropyl, methacryloxypropyl, acrylamidepropyl, methacrylamidepropyl, and 3-(N-maleimide)propyl. Examples of the cationic polymerizable group include groups such as a vinyl ether group, an epoxy group-containing group, and an oxetane group-containing group, such as CH2=CH-O-(CH2)n- (n is an integer of 3 to 20), and glycidyloxy-(CH2) n -(n is an integer from 3 to 20), 3,4-epoxycyclohexyl-(CH2) n -(n is an integer of 2 to 20) and the like. The ultraviolet-reactive functional group is preferably one or more epoxy-containing groups, and particularly preferably an epoxycyclohexylalkyl group, in particular a 3,4-epoxycyclohexylethyl group.

[0051] In formula (3'), R other than the ultraviolet-reactive functional group 1 From R 8are each independently selected from unsubstituted or fluorine-substituted monovalent hydrocarbon groups, preferably unsubstituted or fluorine-substituted alkyl, cycloalkyl, arylalkyl, and aryl groups having 1 to 20 carbon atoms. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, pentyl, and octyl groups, with methyl 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 phenyl and naphthyl groups. Examples of the fluorine-substituted monovalent hydrocarbon group include 3,3,3-trifluoropropyl and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. Examples of the fluorine-substituted monovalent hydrocarbon group include 3,3,3-trifluoropropyl groups. By introducing fluorine atoms into the organopolysiloxane of formula (3'), the relative dielectric constant of the cured product obtained from the composition of the present invention may be further reduced.

[0052] The organosiloxane or organopolysiloxane represented by formula (3') has one ultraviolet-reactive functional group per molecule.

[0053] There are no limitations on the position of the UV-curable functional group in the organosiloxane or organopolysiloxane represented by formula (3'). Only the molecular terminal groups, i.e., only one of R1 to R3 or only one of R6 to R8, may be a UV-reactive functional group, or only one of the non-terminal groups R4 to R5 in formula (3') may be a UV-reactive functional group. Specific examples of organosiloxanes or organopolysiloxanes having one UV-reactive functional group in the molecule, as represented by formula (3'), include 1-(3,4-epoxycyclohexylethyl)-1,1,3,3,3-pentamethyldisiloxane, 1-(3,4-epoxycyclohexylethyl)-1,1,3,3,5,5,5-heptamethyltrisiloxane, 3-(3,4-epoxycyclohexylethyl)-1,1,1,3,5,5,5-heptamethyltrisiloxane, and 1-(3,4-epoxycyclohexylethyl)-1,1,3,3,5,5,7,7,7-nonamethyltetrasiloxane.

[0054] The n in formula (3') is preferably a value that gives the organosiloxane or organopolysiloxane represented by formula (3') a viscosity at 25°C of 1 to 500 mPa·s, more preferably a value that gives 1 to 100 mPa·s, and particularly preferably a value that gives 5 to 50 mPa·s. A person skilled in the art can easily determine the value of n so that the viscosity of the organosiloxane or organopolysiloxane of formula (3') falls within the above-mentioned viscosity range without the need for excessive trial and error. However, in general, the number of n is preferably 0 to 100, more preferably in the range of 0 to 10, so that the compound of formula (3') has the desired viscosity.

[0055] The organosiloxane or organopolysiloxane of formula (3') can be used alone or as a mixture of two or more. When two or more organosiloxanes and / or organopolysiloxanes are used as a mixture, the viscosity of the mixture at 25°C is preferably 1 to 500 mPa·s, more preferably 1 to 100 mPa·s, and particularly preferably 5 to 50 mPa·s.

[0056] The compound of formula (2) above may be a cyclic organopolysiloxane represented by formula (5) below. formula: [ka] In formula (5), each R is independently a group selected from an ultraviolet-reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, and x is an integer of 3 to 10, and there is only one ultraviolet-reactive functional group in the molecule.

[0057] The ultraviolet-reactive functional group and the monovalent hydrocarbon group are as defined for formula (2) above. Specific examples of organosilanes represented by formula (5) include 3,4-epoxycyclohexylethyl-pentamethylcyclotrisiloxane, 3,4-epoxycyclohexylethyl-heptamethylcyclotetrasiloxane, and 3,4-epoxycyclohexylethyl-nonamethylcyclopentasiloxane.

[0058] On the other hand, the preferred viscosity of the organopolysiloxane represented by formula (5) is also as defined above for the organopolysiloxane represented by formula (2).

[0059] Furthermore, the compound of formula (2) above may be an organosilane represented by formula (6) below. Formula: RSiR'3(6) In formula (6), R is an ultraviolet-reactive functional group, and R' is a group selected from a monovalent hydrocarbon group other than the ultraviolet-reactive functional group, a hydroxyl group, and an alkoxy group. The ultraviolet-reactive functional group and the monovalent hydrocarbon group are as defined for the above formula (2), and the alkoxy group is an alkoxy group having 1 to 20 carbon atoms, preferably 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms, or a cycloalkyl group having 5 to 20 carbon atoms. Specifically, a methoxy group, an ethoxy group, an isopropoxy group, a cyclopentyl group, or a cyclohexyl group is preferred.

[0060] Specific examples of organosilanes represented by formula (6) include 3,4-epoxycyclohexylethyltriethylsilane, 3,4-epoxycyclohexylethyldimethylphenylsilane, 3,4-epoxycyclohexylethyldimethyloctylsilane, 3,4-epoxycyclohexylethyldimethylcyclohexylsilane, 3,4-epoxycyclohexylethyltrihexylsilane, and 3,4-epoxycyclohexylethyltributylsilane.

[0061] The preferred viscosity of the organopolysiloxane represented by formula (6) is as defined above for the organopolysiloxane represented by formula (2).

[0062] When the ultraviolet-reactive functional group of the organosiloxane and / or organopolysiloxane represented by formula (1), (3), or (4) is a radical polymerizable group, it is preferable that the ultraviolet-reactive functional group of the organosilane or linear, branched, or cyclic organopolysiloxane represented by formula (2), (3'), (5), or (6) is also a radical polymerizable group.In addition, when the ultraviolet-reactive functional group of the organosiloxane or organopolysiloxane represented by formula (1), (3), or (4) is a cationic polymerizable functional group, it is preferable that the ultraviolet-reactive functional group of the organosiloxane or linear, branched, or cyclic organopolysiloxane represented by formula (2), (3'), (5), or (6) is also a cationic polymerizable functional group, such as an epoxy group, a glycidyloxy group, and a vinyl ether group.

[0063] The organosiloxane or organopolysiloxane represented by the above formula (2) or (3'), the cyclic organopolysiloxane represented by the above formula (5), or the organosilane represented by the above formula (6) may each be used alone or in any combination of two or more. That is, the organosiloxane or organopolysiloxane represented by the formula (2) or (3'), the cyclic organopolysiloxane represented by the formula (5), or the organosilane represented by the formula (6), or a mixture of two or more selected from them may be used as component (B) of the composition of the present invention.

[0064] [Photopolymerization initiator] In addition to the above-mentioned components (A) and (B), a photopolymerization initiator can be added to the ultraviolet-curable organopolysiloxane composition of the present invention, if desired. In this case, when the ultraviolet-reactive functional groups of components (A) and (B) are cationic polymerizable functional groups containing epoxy or vinyl ether, a photocationic polymerization initiator is used as the photopolymerization initiator. As the photocationic polymerization initiator, a compound capable of generating a Bronsted acid or a Lewis acid by irradiation with ultraviolet rays or an electron beam, that is, a so-called photoacid generator, is known, and it is known that an acid is generated by irradiation with ultraviolet rays or the like, and the acid causes a reaction between cationic polymerizable functional groups. In addition, when the ultraviolet-reactive functional group is a radical polymerizable functional group, a photoradical polymerization initiator can be used as the photopolymerization initiator. The photoradical polymerization initiator generates free radicals by irradiation with ultraviolet rays or an electron beam, which cause a radical polymerization reaction to cure the composition of the present invention. When the composition of the present invention is cured by irradiation with an electron beam, a polymerization initiator is usually not required.

[0065] (1) Photocationic polymerization initiator The photocationic polymerization initiator used in the composition of the present invention can be selected from those known in the art and is not particularly limited. Strong acid generating compounds such as diazonium salts, sulfonium salts, iodonium salts, and phosphonium salts are known as photocationic polymerization initiators, and these can be used. Examples of photocationic polymerization initiators include bis(4-tert-butylphenyl)iodonium hexafluorophosphate, cyclopropyldiphenylsulfonium tetrafluoroborate, dimethylphenacylsulfonium tetrafluoroborate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, diphenyliodonium tetrafluoromethanesulfonate, 2-(3,4-dimethoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(furan-2-yl)vinyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, and 4-isopropyl-4'-methyldiphenyliodonium. Tetrakis(pentafluorophenyl)borate, 2-[2-(5-methylfuran-2-yl)vinyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-Triazine, 4-nitrobenzenediazonium tetrafluoroborate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium bromide, tri-p-tolylsulfonium hexafluorophosphate, tri-p-tolylsulfonium trifluoromethanesulfonate, diphenyliodonium triflate, triphenylsulfonium triflate, diphenyliodonium nitrate, bis(4-tert-butylphenyl)iodonium perfluoro-1-butanesulfonate, bis(4-tert-butylphenyl)iodonium triflate, triphenylsulfonium perfluoro-1-butanesulfonate, N-hydroxynaphthalimide triflate, p-toluenesulfonate, diphenyliodonium p-toluenesulfonate, (4-tert-butylphenyl)diphenylsulfonium triflate, tris(4-tert-butylphenyl)sulfonium triflate, N-hydroxy-5-norbornene-2,3-dicarboximide Examples of the photocationic polymerization initiator include, but are not limited to, perfluoro-1-butanesulfonate, (4-phenylthiophenyl)diphenylsulfonium triflate, and 4-(phenylthio)phenyldiphenylsulfonium triethyltrifluorophosphate. In addition to the above compounds, examples of the photocationic polymerization initiator include commercially available photoinitiators such as Omnicat 250, Omnicat 270 (both from IGM Resins BV), CPI-310B, IK-1 (both from San-Apro Co., Ltd.), DTS-200 (Midori Chemical Co., Ltd.), and Irgacure 290 (BASF).

[0066] The amount of the cationic photopolymerization initiator added to the composition of the present invention is not particularly limited as long as the desired photocuring reaction occurs. In general, however, it is preferable to use the cationic photopolymerization initiator in an amount of 0.1 to 5 mass %, particularly 0.2 to 3 mass %, based on the total amount of the components (A) and (B) of the present invention.

[0067] (2) Photoradical polymerization initiator Photoradical polymerization initiators are roughly divided into photocleavage type and hydrogen abstraction type, and the photoradical polymerization initiator used in the composition of the present invention can be arbitrarily selected from those known in the art and is not particularly limited to a specific one. Examples of photoradical polymerization initiators include acetophenone, p-anisyl, benzyl, benzoin, benzophenone, 2-benzoylbenzoic acid, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin ethyl ether, 4-benzoylbenzoic acid, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, methyl 2-benzoylbenzoate, 2-(1,3-benzodioxol-5-yl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-benzyl-2-(dimethylamino)- 4'-Morpholinobutyrophenone, (±)-Camphorquinone, 2-Chlorothioxanthone, 4,4'-Dichlorobenzophenone, 2,2-Diethoxyacetophenone, 2,2-Dimethoxy-2-phenylacetophenone, 2,4-Diethylthioxanthen-9-one, Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, Ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate, 1,4-Dibenzoylbenzene, 2-Ethylanthraquinone, 1-Hydroxycyclohexyl phenyl ketone, 2-Hydroxy-2-methylpropiophenone, 2-Hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 2-Isopropylthioxanthone, Lithium These include, but are not limited to, phenyl(2,4,6-trimethylbenzoyl)phosphineate, 2-methyl-4'-(methylthio)-2-morpholinopropiophenone, 2-isonitrosopropiophenone, 2-phenyl-2-(p-toluenesulfonyloxy)acetophenone, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.In addition to the above compounds, examples of the photoradical polymerization initiator include Omnirad 651, 184, 1173, 2959, 127, 907, 369, 369E, and 379EG (alkylphenone-based photopolymerization initiators, IGM Resins BV), Omnirad TPO H, TPO-L, and 819 (acylphosphine oxide-based photopolymerization initiators, IGM Resins BV), Omnirad MBF and 754 (intramolecular hydrogen abstraction type photopolymerization initiators, IGM Resins BV), and Irgacure OXE01 and OXE02 (oxime ester-based non-polymerization initiators, BASF).

[0068] The amount of the photoradical polymerization initiator added to the composition of the present invention is not particularly limited as long as the desired photopolymerization reaction or photocuring reaction occurs, but it is generally used in an amount of 0.01 to 5 mass %, preferably 0.05 to 1 mass %, relative to the total mass of the composition of the present invention.

[0069] A photosensitizer can also be used in combination with the photocationic or radical photopolymerization initiator. The use of a sensitizer can increase the photon quantum efficiency of the polymerization reaction, and since light of a longer wavelength can be used for the polymerization reaction compared to the case where only a photoinitiator is used, it is known to be particularly effective when the coating thickness of the composition is relatively thick or when an LED light source with a relatively long wavelength is used. As sensitizers, anthracene-based compounds, phenothiazine-based compounds, perylene-based compounds, cyanine-based compounds, merocyanine-based compounds, coumarin-based compounds, benzylidene ketone-based compounds, (thio)xanthene or (thio)xanthone-based compounds, such as isopropylthioxanthone, 2,4-diethylthioxanthone, squalium-based compounds, (thia)pyrylium-based compounds, and porphyrin-based compounds, are known, and any photosensitizer can be used in the curable composition of the present invention, without being limited to these.

[0070] The mass ratio of components (A) and (B) contained in the composition of the present invention is not particularly limited, but the amount of component (A) relative to the total amount of (A) and (B) (100% by mass) is less than 75% by mass, preferably less than 60% by mass, particularly preferably less than 55% by mass, and even more preferably less than 50% by mass.

[0071] The cured product obtained from the curable composition of the present invention can be designed to have the desired hardness, tear strength, tensile strength, viscoelasticity including elongation at break, adhesive strength, curing reaction rate, etc. of the cured product by selecting the siloxane chain length, crosslinking density, crosslinking reaction site and structure of component (A) and component (B). For example, it is possible to design the molecular structure so that the cured product has physical properties according to the application of the cured product by selecting a polymer with molecular chain end reactivity, a polymer with molecular chain side chain reactivity, a resinous or branched polymer, etc., and the cured product is 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 it may be a thin film coating layer, a molded product such as a sheet, or it may be injected into a specific part in an uncured state and cured to form a filling, or it may be used as a sealant or intermediate layer for a laminate or a display device.

[0072] In addition, the cured product obtained from the composition of the present invention is substantially transparent and can be used for adhesion or fixing between members, so it can be used as an optically transparent adhesive (OCA) or optically transparent resin (OCR). Furthermore, the cured product obtained from the composition of the present invention can form not only a resin-like cured product with high hardness, but also a soft elastomeric cured product or a gel-like cured product, so it may be used for optical members, electronic members, protective materials for electronic materials, functional elastomers, functional gels, etc., which require a low relative dielectric constant. In addition, further functions may be imparted by using additives, etc., which will be described later.

[0073] In particular, the cured product obtained from the composition of the present invention is characterized by a low dielectric constant, and therefore the 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 and electrical devices.

[0074] When the composition of the present invention is used as a coating agent, in order to provide the composition with suitable fluidity and workability for application to a substrate, the viscosity of the entire composition is preferably 1 to 100 mPa·s, more preferably 1 to 50 mPa·s, even more preferably 5 to 30 mPa·s, and particularly preferably 5 to 20 mPa·s at 25° C. In order to adjust the viscosity of the entire composition to a desired viscosity, it is preferable to use, as components (A) and (B), organosilanes, organosiloxanes, and / or organopolysiloxanes represented by formulas (1), (2), (3), (3'), (4), (5), and (6) having a viscosity such that the viscosity of the entire composition becomes the desired viscosity. To achieve this, the molecular weight of the organosiloxane and / or organopolysiloxane represented by formulas (1) and (2) can be adjusted to a preferred range, and the molecular weight can be adjusted appropriately by selecting R and R' of the organopolysiloxanes of formulas (1) and (2) and adjusting the degree of polymerization of the polysiloxane, adjusting n in formulas (3) and (3'), adjusting the values ​​of e, f, g, and h in formula (4), selecting R and x in formula (5), or selecting the groups for R and R' in formula (6).

[0075] A non-volatile or low-volatile low molecular weight compound may be added to adjust the viscosity of the composition, improve the applicability, and adjust the physical properties of the cured product. Such a low molecular weight compound is preferably non-volatile or low-volatile with a molecular weight of 500 or less, has a boiling point of more than 150°C at normal pressure, and has a symmetrical molecular structure so as to maintain low dielectric properties, but is not limited thereto. It may also be a compound having an ultraviolet-reactive functional group. Specific examples of such low molecular weight compounds include dodecane, tetradecane, hexadecane, dodecene, tetradecene, hexadecene, allyl glycidyl ether, butyl glycidyl ether, 1,2-epoxy-4-vinylcyclohexane, (3,4-epoxycyclohexyl)methyl acrylate, 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The amount of the compound is the amount required to adjust the viscosity of the composition, and may be 5% or less, or even 2% or less of the entire composition. When the ultraviolet-curable group contained in the curable composition of the present invention is a cationic polymerizable group, the low molecular weight compound having an epoxy group can also be called a reactive diluent.

[0076] Compounds that act as reactive diluents, have one or more UV-reactive functional groups in one molecule, and do not contain silicon atoms can be used as component (C). The content of component (C) is such that the mass ratio of component (C) to the total of components (A), (B), and (C) is less than 50% in order to suppress an increase in the relative dielectric constant. The mass ratio of component (C) to the total of components (A), (B), and (C) is preferably less than 30%, more preferably less than 10%.

[0077] As component (C), a compound having one UV-reactive functional group in one molecule and not containing silicon atoms is preferable, and a compound having one epoxy group in one molecule and not containing oxetane groups or silicon atoms is more preferable.Specific examples include the above-mentioned allyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, 1,2-epoxy-4-vinylcyclohexane, and (3,4-epoxycyclohexyl)methyl acrylate.

[0078] [Component (D)] In order to improve the wettability of the composition to the substrate and form a coating film without defects when the ultraviolet-curable organopolysiloxane composition of the present invention is applied as a coating agent to the surface of a substrate by any method, it is preferable to further add a component (D) selected from the following to the composition of the present invention containing the above-mentioned components. It is particularly preferable to use an inkjet printing method as a method for coating the composition of the present invention to a substrate. Therefore, component (D) is a component that improves the wettability of the ultraviolet-curable organopolysiloxane composition of the present invention to the substrate and significantly improves the inkjet printing characteristics in particular. Component (D) is at least one compound selected from the group consisting of the following (D1), (D2), and (D3).

[0079] (i) Component (D1) Component (D1) is a nonionic surfactant that does not contain silicon atoms and is not acrylic, that is, a nonacrylic nonionic surfactant. Nonacrylic refers to a surfactant that does not have a (meth)acrylate group in its molecule. Examples of surfactants that can be used as component (D1) 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, and fluorine-based nonionic surfactants, and these can be used alone or in combination of two or more. Specific examples of component (D1) include organic nonionic surfactants such as the Emulgen series and Leodol series manufactured by Kao Corporation, the Surfynol 400 series manufactured by Evonik Industries, and the Olfin E series manufactured by Nissin Chemical Industry Co., Ltd., and fluorine-based nonionic surfactants such as the FC-4400 series manufactured by 3M, and the Megafac 550 and 560 series manufactured by DIC Corporation. Among these, the alkynol polyethers Surfynol 400 series and Olfine E series are particularly preferred.

[0080] (ii) Component (D2) is a nonionic surfactant containing silicon atoms and having an HLB value of 4 or less. Here, the HLB value is a value that indicates the degree of affinity of a surfactant to water and organic compounds, and here, the value defined by the Griffin method (20 x sum of formula weights of hydrophilic parts / molecular weight) is used as the HLB value. Silicone polyethers having polyether as the hydrophilic part, glycerol silicones having (di)glycerol derivatives as the hydrophilic part, carbinol silicones having hydroxyethoxy groups as the hydrophilic part, and the like are known as silicon-containing nonionic surfactants. Among these surfactants, those having an HLB value of 4 or less, that is, those having a mass fraction of the hydrophilic part of 20 mass% or less are preferably used in the composition of the present invention. Among these, carbinol silicones are particularly preferred.

[0081] (iii) Component (D3) is a silicone oil having a viscosity of 90 mPa·s or less at 25° C. Examples of silicone oils include polydimethylsiloxane having trimethylsilyl terminals at both ends, polydimethylsiloxane having dimethylvinylsilyl terminals at both ends, copolymer having trimethylsilyl-dimethylsiloxy / methylvinylsiloxy terminals at both ends, copolymer having dimethylvinylsilyl-dimethylsiloxy / methylvinylsiloxy terminals at both ends, copolymer having trimethylsilyl-dimethylsiloxy / methylphenylsiloxy terminals at both ends, copolymer having trimethylsilyl-dimethylsiloxy / diphenylsiloxy terminals at both ends, copolymer having dimethylvinylsilyl-dimethylsiloxy / methylphenylsiloxy terminals at both ends, copolymer having dimethylvinylsilyl-dimethylsiloxy / diphenylsiloxy terminals at both ends, and copolymer having dimethylvinylsilyl-dimethylsiloxy / diphenylsiloxy terminals at both ends. Of these, polydimethylsiloxane having trimethylsilyl terminals and polydimethylsiloxane having dimethylvinylsilyl terminals at both ends are preferably used. The silicone oil has a preferred viscosity range of 2 to 50 mPa s, more preferably 2 to 30 mPa s, and even more preferably 5 to 20 mPa s, where the viscosity values ​​are values ​​measured at 25°C using the rotational viscometer described in the examples.

[0082] The above-mentioned components (D1) to (D3) can be used alone or in combination of two or more thereof. The amount of component (D) to be blended in the curable composition is not particularly limited, but the total amount of the above-mentioned components (A) to (C) is taken as 100 mass%, and the total amount of the components (D1) to (D3) (collectively referred to as component (D)) is preferably 0.05 mass% or more and 1 mass% or less relative to the total amount. If the amount of component (D) is less than 0.05 mass% relative to the total amount of the components (A) to (C), which is 100 mass%, the effect of improving the wettability of the curable composition to the substrate may not be sufficiently obtained, and if the amount of component (D) is more than 1 mass% relative to the total amount of the components (A) to (C), which is 100 mass%, there is a risk that the component (D) will bleed out from the cured product after curing.

[0083] As component (D), it is preferable to use the silicone oil of component (D3) alone or in combination with one or more components selected from the group consisting of components (D1) and (D2), and it is particularly preferable to use component (D3) alone as component (D).

[0084] Other Additives In addition to the above components, further additives may be added to the composition of the present invention as desired. Examples of additives include, but are not limited to, the following:

[0085] [Adhesion imparting agent] An adhesion promoter can be added to the composition of the present invention in order to improve adhesion or adhesion to a substrate in contact with the composition. When the curable composition of the present invention is used for applications requiring adhesion or adhesion to a substrate, such as a coating agent or a sealing material, it is preferable to add an adhesion imparting agent to the curable composition of the present invention. As the adhesion promoter, any known adhesion promoter can be used as long as it does not inhibit the curing reaction of the composition of the present invention.

[0086] Examples of adhesion promoters that can be used in the present invention include organosilanes having a trialkoxysiloxy group (e.g., trimethoxysiloxy group, triethoxysiloxy group) or a trialkoxysilylalkyl group (e.g., trimethoxysilylethyl group, triethoxysilylethyl group) and a hydrosilyl group or an alkenyl group (e.g., vinyl group, allyl group), or organosiloxane oligomers having a linear, branched or cyclic structure with about 4 to 20 silicon atoms; organosilanes having a trialkoxysiloxy group or a trialkoxysilylalkyl group and a methacryloxyalkyl group (e.g., 3-methacryloxypropyl group); organosilanes, or organosiloxane oligomers having a linear, branched, or cyclic structure with about 4 to 20 silicon atoms; organosilanes having a trialkoxysiloxy group or a trialkoxysilylalkyl group and an 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 organosiloxane oligomers having a linear, branched, or cyclic structure with about 4 to 20 silicon atoms; organic compounds having two or more trialkoxysilyl groups (e.g., trimethoxysilyl group, triethoxysilyl group);Examples of the reaction product of aminoalkyltrialkoxysilane and epoxy group-bonded alkyltrialkoxysilane, and epoxy group-containing ethyl polysilicate include vinyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, hydrogentriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 1,6-bis(trimethoxysilane), silyl)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, condensation reaction product of silanol group-blocked methylvinylsiloxane oligomer and 3-glycidoxypropyltrimethoxysilane, condensation reaction product of silanol group-blocked methylvinylsiloxane oligomer and 3-methacryloxypropyltriethoxysilane, and tris(3-trimethoxysilylpropyl)isocyanurate.

[0087] The amount of adhesion promoter added to the curable composition of the present invention is not particularly limited, but in order not to promote the curing characteristics of the curable composition or discoloration of the cured product, it is preferably within the range of 0.01 to 5 parts by mass, or within the range of 0.01 to 2 parts by mass, relative to 100 parts by mass of the total of components (A) and (B).

[0088] [Other additives] In addition to the adhesion promoter described above, or instead of the adhesion promoter, other additives may be added to the composition of the present invention as desired. Examples of additives that can be used include leveling agents, silane coupling agents not included in the adhesion promoters described above, ultraviolet absorbers, antioxidants, polymerization inhibitors, fillers (functional fillers such as reinforcing fillers, insulating fillers, and thermally conductive fillers), and the like. If necessary, appropriate additives can be added to the composition of the present invention. In addition, if necessary, a thixotropic agent may be added to the composition of the present invention, especially when the composition is used as a potting agent or a sealing material.

[0089] [Dielectric constant of the cured product of the composition of the present invention] The cured product obtained from the ultraviolet-curable organopolysiloxane composition of the present invention can have a low dielectric constant, and the relative dielectric constant can be less than 3.0, and preferably less than 2.8. The relative dielectric constant is a value measured under conditions of 23° C. and 100 kHz.

[0090] [Application] The ultraviolet-curable organopolysiloxane composition of the present invention can be cured not only by ultraviolet light, but also by electron beams, which is also one embodiment of the present invention.

[0091] The composition of the present invention can be used as an insulating material by utilizing the characteristic that the relative dielectric constant of the cured product obtained therefrom is low. Specifically, the composition of the present invention is particularly useful as a material for forming an insulating layer constituting various articles, particularly electronic devices and electric devices. The composition of the present invention can be applied onto 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 the composition can be cured by irradiating the composition with ultraviolet rays or electron beams to form an insulating layer. In this case, a pattern can be formed when the composition of the present invention is applied to a substrate, and then the composition can be cured, or the composition can be applied to a substrate, and when curing, the cured and uncured parts can be left by irradiation with ultraviolet rays or electron beams, and then the uncured parts can be removed with a solvent to form an insulating layer of a desired pattern.

[0092] The curable composition of the present invention is particularly suitable as a material for forming an insulating layer of a display device such as a touch panel or a display. In this case, the insulating layer may be formed into any desired pattern as described above, if necessary. Therefore, a display device such as a touch panel or a display including an insulating layer obtained by curing the ultraviolet-curable organopolysiloxane composition of the present invention is also an embodiment of the present invention.

[0093] 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. In addition, the curable composition of the present invention can be cured to form a cured product, which can be used as an insulating coating layer.

[0094] The insulating film formed from the curable composition of the present invention can be used for various applications. In particular, it can be used as a component of an electronic device or as a material used in the process of manufacturing an electronic device. The electronic device includes electronic devices such as semiconductor devices and magnetic recording heads. For example, the curable composition of the present invention can be used as an insulating film for semiconductor devices such as LSI, system LSI, DRAM, SDRAM, RDRAM, D-RDRAM, and multi-chip module multilayer wiring boards, an interlayer insulating film for semiconductors, an etching stopper film, a surface protective film, a buffer coat film, a passivation film in LSI, a cover coat for flexible copper-clad boards, a solder resist film, and a surface protective film for optical devices.

[0095] In addition to being used as a coating agent, the ultraviolet-curable organopolysiloxane composition of the present invention is also suitable for use as a potting agent, particularly as an insulating potting agent for electronic and electrical devices.

[0096] The composition of the present invention can be used as a material for forming a coating layer on a substrate surface, particularly by using an inkjet printing method. In this case, it is particularly preferable that the composition of the present invention contains the above-mentioned component (D).

[0097] The present invention will be further described below based on examples, but the present invention is not limited to the following examples. EXAMPLES

[0098] The ultraviolet-curable organopolysiloxane composition of the present invention and its cured product will be described in detail with reference to examples. In the formula, Me and Ep represent a methyl group and a 2-(3,4-epoxycyclohexyl)ethyl group, respectively. Measurements and evaluations in the examples and comparative examples were carried out as follows.

[0099] [Viscosity of Organopolysiloxane and Curable Organopolysiloxane Composition] The viscosity (mPa·s) at 25°C was measured using a rotational viscometer (E-type viscometer VISCONIC EMD manufactured by Tokimec Inc.).

[0100] [Preparation of Curable Organopolysiloxane Composition] The materials in the amounts shown in Table 1 below were placed in a brown plastic container and thoroughly mixed using a planetary mixer to prepare a curable organopolysiloxane composition.

[0101] [Wettability of the curable organopolysiloxane composition to the substrate (contact angle of the composition)] Two microliters of the curable composition was dropped onto a silicon nitride-coated glass substrate, and the contact angle of the curable composition immediately after dropping and after 1 minute was measured at 23° C. using a contact angle measuring device DM-700 manufactured by Kyowa Interface Science Co., Ltd. The unit of contact angle is degrees (°).

[0102] [Inkjet Printing Properties of Curable Organopolysiloxane Composition] Using a Unijet inkjet printer Omnijet 200 equipped with a print head KM-1204, the curable composition was printed in droplets of 14 picoliters onto a silicon nitride-coated glass substrate in a size of 155 × 89 mm so that the thickness after curing was 4 micrometers. 2 The curable composition was applied to a range of 100 mm. The applicability was evaluated by rating it as "○" if there was no uncoated area in the applied area and it was printed uniformly, and rating it as "×" if there was an uncoated area. In addition, the size of the droplets (unit: micrometer) immediately after the curable composition was applied to the substrate by the inkjet method and 1 minute after application were photographed to evaluate the spreadability of the droplets (measurement of the droplet size of the composition).

[0103] [Curing of the Curable Organopolysiloxane Composition] A 1 mm thick mold with a circular hole with an inner diameter of 40 mm was placed on a PET film coated with a fluoropolymer release agent, and about 1.3 g of a curable organopolysiloxane composition was poured into the hole. The composition was covered with the same PET film as above, and a 10 mm thick glass plate was placed on top of that. LED light with a wavelength of 365 nm was irradiated from above at 2 J / cm. 2 The composition was cured by irradiating it with an energy amount of 1.0 g / cm 2 , to produce a disk-shaped cured organopolysiloxane product having a diameter of 40 mm and a thickness of 1 mm.

[0104] [Dielectric constant of cured organopolysiloxane] Tin foil with a diameter of 33 mm and a thickness of 0.007 mm was pressure-bonded to both sides of the organopolysiloxane cured product. To improve the adhesion between the cured product and the foil, a small amount of silicone oil was used for pressure bonding, if necessary. The capacitance was measured at room temperature (23°C) and 100 KHz using a Keysight Technologies E4990A precision impedance analyzer connected to a parallel plate electrode with a diameter of 30 mm. The relative dielectric constant was calculated using the measured capacitance value, the thickness of the cured product measured separately, and the electrode area value.

[0105] [Examples and Comparative Examples 1] Using the components below, ultraviolet-curable organopolysiloxane compositions having the compositions (parts by mass) shown in Table 1 were prepared. (A)(EpMe2Si)2O (B) EpMeSi(OSiMe3)2 (C) 1,2-epoxy-4-vinylcyclohexane (D1, D2) Catalyst master batch composed of the following components D1:(D1a) / (X) / (Y)=48 / 2 / 50(mass ratio) D2:(D2a) / (X) / (Y)=48 / 2 / 50(mass ratio) (D1a): CPI-310B (manufactured by San-Apro Co., Ltd.) (D2a): 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (X): 2-isopropylthioxanthone (Y): 1,2-epoxy-4-vinylcyclohexane

[0106] [Table 1]

[0107] As shown in the above table, the ultraviolet-curable organopolysiloxane compositions of the present invention (Examples 1 to 7) have a viscosity at 25°C suitable for application to a substrate as a coating agent. Furthermore, the ultraviolet-curable organopolysiloxane composition of the present invention has the effect of lowering the relative dielectric constant of the cured product obtained by ultraviolet irradiation by using an organo(poly)siloxane having two or more ultraviolet-reactive groups in one molecule and one or more silicon-containing compounds having one ultraviolet-reactive functional group in one molecule. On the other hand, the compositions (Comparative Examples 1 to 3) that do not contain one or more silicon-containing compounds having one ultraviolet-reactive functional group in one molecule have a higher relative dielectric constant of the cured product than those of Examples 1 to 7.

[0108] [Example and Reference Example 2] Using the components listed below, ultraviolet-curable organopolysiloxane compositions having the compositions (parts by mass) shown in Tables 2 and 3 were prepared. (A)(EpMe2Si)2O (B) EpMeSi(OSiMe3)2 (D) The following compound: D1a: Surfynol 420 (manufactured by Evonik Industries) HLB value: 4 D1b: Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) HLB value: 14 D2a: DOWSIL TM 67 Additive (Dow Chemical Company) HLB value: 12 D2b:DOWSIL TM 5562 Carbinol Fluid (Dow Chemical Company) HLB value: 2 D3a: DOWSIL TMSH 200 Fluid 100mPa.s (Dow Chemical Company) HLB value: 0 D3b:DOWSIL TM SH 200 Fluid 20mPa.s (Dow Chemical Company) HLB value: 0 D3c:DOWSIL TM SH 200 Fluid 5mPa.s (Dow Chemical Company) HLB value: 0 (E) A catalyst masterbatch consisting of the following components: E:(E1) / (X) / (B)=30 / 2.4 / 67.6 (mass ratio) (E1): 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (X): 2-isopropylthioxanthone

[0109] [Table 2]

[0110] [Table 3]

[0111] As shown in Table 2, the ultraviolet-curable organopolysiloxane compositions of the present invention (Examples 8 to 12) have a viscosity at 25°C suitable for application to a substrate as a coating agent, and are highly transparent. Furthermore, the ultraviolet-curable organopolysiloxane composition of the present invention contains a specific wettability improver (component D1a, etc.), which significantly reduces the contact angle with the substrate. Furthermore, the relative dielectric constant of the cured product obtained by ultraviolet irradiation is also low. On the other hand, the compositions containing the specific wettability improver (Examples 8 to 12) have a lower contact angle with the substrate and the same or better transparency than the compositions not containing the specific wettability improver (Reference Examples 1 to 3). Furthermore, it was confirmed that the ultraviolet-curable organopolysiloxane compositions of the present invention also have excellent applicability by inkjet printing, as shown in Table 3. [Industrial Applicability]

[0112] The ultraviolet-curable organopolysiloxane composition of the present invention is particularly suitable for the above-mentioned applications, in particular as a material for forming insulating layers in display devices such as touch panels and displays.

Claims

1. (A) (EpMe2Si)2O, and (B) EpMeSi(OSiMe 3 ) 2 (In these formulas, Me represents a methyl group, and Ep represents a 2-(3,4-epoxycyclohexyl)ethyl group.) A material for forming an insulating layer of a display device, comprising an ultraviolet-curable organopolysiloxane composition containing the above as an essential curable component and not containing any organic solvent in the composition.

2. The material according to claim 1, wherein the ratio of component (A) is less than 80% by mass relative to 100% by mass of the sum of components (A) and (B).

3. The material according to claim 1, wherein the ratio of component (A) is less than 50% by mass relative to 100% by mass of the sum of components (A) and (B).

4. The material according to any one of claims 1 to 3, further comprising (C) a compound having one or more ultraviolet-reactive functional groups in one molecule and having no silicon atoms, wherein the mass ratio of component (C) to the total of components (A), (B), and (C) is less than 50%.

5. 5. The material according to claim 4, wherein component (C) is a compound having one epoxy group in one molecule and containing no oxetane group or silicon atom.

6. (D) The following (D1), (D2), and (D3): (D1) a non-acrylic nonionic surfactant not containing a silicon atom, (D2) a nonionic surfactant containing a silicon atom and having an HLB value of 4 or less; (D3) a silicone oil having a viscosity of 90 mPa·s or less at 25°C; The material according to any one of claims 1 to 5, further comprising at least one compound selected from the group consisting of:

7. The material according to any one of claims 1 to 6, wherein the composition is substantially free of a compound that contains an oxetane group in the molecule and does not contain a silicon atom.

8. The material of any one of claims 1 to 7, wherein the ultraviolet curable organopolysiloxane composition after curing has a dielectric constant of less than 2.

8. (A) (EpMe2Si)2O, and (B) EpMeSi(OSiMe 3 ) 2 (In these formulas, Me represents a methyl group, and Ep represents a 2-(3,4-epoxycyclohexyl)ethyl group.) The insulating coating agent comprises an ultraviolet-curable organopolysiloxane composition comprising the above as an essential curable component and containing no organic solvent in the composition. (A) (EpMe2Si)2O, and (B) EpMeSi(OSiMe 3 ) 2 (In these formulas, Me represents a methyl group, and Ep represents a 2-(3,4-epoxycyclohexyl)ethyl group.) The cured product of the ultraviolet-curable organopolysiloxane composition contains the above as an essential curing component and does not contain any organic solvent in the composition, and is used as an insulating coating layer. (A) (EpMe2Si)2O, and (B) EpMeSi(OSiMe 3 ) 2 (In these formulas, Me represents a methyl group, and Ep represents a 2-(3,4-epoxycyclohexyl)ethyl group.) A display device comprising a layer made of a cured product of an ultraviolet-curable organopolysiloxane composition, the composition containing the above as an essential curable component and containing no organic solvent.

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