Ultraviolet curable composition and use thereof

Abstract

Provided is an ultraviolet-curable composition containing silicon atoms, the product obtained by curing the composition having excellent mechanical properties and low exhaust characteristics, and also having excellent workability when applied to a substrate. This ultraviolet-curable composition is characterized by containing (A) one or more organopolysiloxanes or organosilanes having more than one cationically polymerizable functional group per molecule on average, (B) a compound that releases a basic substance by heating at 60-200 DEG C, and (C) a photoacid generator, and is substantially free from an organic solvent. The viscosity of the entire composition as measured at 25 DEG C using an E-type viscometer is 500 mPa.s or less.

Description

Technical Field

[0001] The present invention relates to an ultraviolet curable composition that can be cured by actinic rays such as ultraviolet rays or electron beams, and in particular to an ultraviolet curable composition comprising an organosilicon compound, preferably an organosilane and / or an organopolysiloxane, and in particular to an ultraviolet curable composition having good low outgassing (volatile gas) characteristics and excellent coating properties. The curable composition of the present invention has low outgassing properties and excellent mechanical properties, and is suitable for use as an insulating material for electronic devices and electrical equipment, especially display devices, and is particularly suitable for use as a coating and protective layer. Further, it has excellent coating properties and excellent wettability to a substrate, and is useful as an inkjet printing material. Background Art

[0002] Silicone resins have been used as coating agents, potting agents, and insulating materials for electronic devices and electrical equipment due to their high heat resistance and excellent chemical stability. Among silicone resins, ultraviolet curable silicone compositions have also been reported.

[0003] Touch panels are used in various display devices such as mobile devices, industrial equipment, and car navigation. In order to improve its sensing sensitivity, it is necessary to suppress the film response from the light-emitting parts such as light-emitting diodes (LEDs) and organic EL devices (OLEDs), and an insulating layer is usually configured between the light-emitting part and the touch screen.

[0004] On the other hand, thin display devices such as OLED have a structure in which multiple functional thin layers are stacked. In recent years, research has begun on improving the reliability of display devices, especially flexible display devices, by stacking a highly flexible insulating layer on a touch screen layer. In addition, inkjet printing is used as a processing method for organic layers for the purpose of improving productivity. Therefore, materials that can be processed by inkjet printing are also required for the above-mentioned insulating layer.

[0005] International Patent Application Publication No. WO2019 / 117298 discloses a sealant for electronic devices, which is composed of a disiloxane compound having an ultraviolet curable functional group, a polysiloxane having an ultraviolet curable functional group, and an arbitrarily formulated silicon-free compound having an ultraviolet curable functional group, and can be applied by an inkjet method. However, since no chemical consideration is made for reducing the exhaust gas generated when the high temperature is reduced, it cannot be said that the exhaust gas generated by the sealant is sufficiently low.

[0006] On the other hand, International Patent Application Publication No. WO2006 / 100978 and Japanese Patent Application Publication No. 2004-231923 disclose active light-curable compositions that can be printed by inkjet printing and contain alicyclic epoxy or oxetane compounds having a special structure. Among them, the use of a thermal base generator is suggested and studied, but it is recorded that the thermal base generator is used as an additive for improving the ejection stability and storage stability of the composition (paragraph

[0211] of WO2006 / 100978), and there is no record of the exhaust of the cured product. Furthermore, these patent documents do not record or suggest a curable composition containing an organopolysiloxane or organosilane having an epoxy group or an oxetane group.

[0007] In ultraviolet curing type sealants for electric and electronic components, particularly curable compositions containing organopolysiloxane or organosilane, the outgassing characteristics at high temperatures still remain as characteristics that need to be improved.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: WO2019-117298

[0011] Patent Document 2: WO2006-100978

[0012] Patent Document 3: Japanese Patent Application Publication No. 2004-231923 Summary of the invention

[0013] Problems to be solved by the invention

[0014] As described above, UV-curable organopolysiloxane compositions, particularly UV-curable organopolysiloxane compositions capable of inkjet printing, have been widely disclosed, but there is still a need for a UV-curable composition whose cured product has low outgassing characteristics and excellent workability for coating on a substrate, particularly low viscosity. The object of the present invention is to provide a curable composition containing silicon atoms, particularly a UV-curable composition, which has low outgassing characteristics when cured and excellent workability when coated on a substrate.

[0015] Solutions for solving problems

[0016] The present invention has been accomplished by finding that a UV-curable composition obtained by using in combination (A) one or more organopolysiloxanes or organosilanes having an average number of more than one cationically polymerizable functional group in one molecule, (B) a compound that releases a basic substance when heated at 60 to 200° C., and (C) a photoacid generator has a low viscosity and excellent workability when applied to a substrate, and that a cured product obtained by curing the composition exhibits low outgassing characteristics.

[0017] The present invention relates to an ultraviolet curable composition containing an organosilicon compound, and in particular to an ultraviolet curable organopolysiloxane composition. The composition can also be cured by forming a bond based on an ultraviolet curable functional group, but its curing method is not limited to ultraviolet irradiation, and any method that can cause a curing reaction using the ultraviolet curable functional group can also be used, for example, electron beam irradiation can be used to cure the composition of the present invention.

[0018] The ultraviolet curable composition of the present invention is characterized in that it contains (A) one or more organopolysiloxanes or organosilanes having an average number of more than 1 cationic polymerizable functional groups in one molecule, (B) a compound that releases a basic substance by heating at 60 to 200° C., and (C) a photoacid generator, the viscosity of the entire composition measured at 25° C. using an E-type viscometer is 500 mPa·s or less, the composition does not contain an organic solvent, and the cured product of the composition has low outgassing characteristics when cured. It should be noted that, unless otherwise specified in this specification, the viscosity of a substance is a value measured at 25° C. using an E-type viscometer.

[0019] The cationically polymerizable reactive group possessed by the component (A) of the present invention is an arbitrary group capable of forming a bond in the presence of an acid generated by the photoacid generator of the component (C) by irradiation with ultraviolet rays or the like. Examples of the cationically polymerizable functional group include a vinyl ether group, an epoxy group-containing group, an oxetane group-containing group, for example, CH2=CH-O-(CH2)n- (n is an integer of 3 to 20), a glycidyloxy-(CH2) n -(n is an integer from 3 to 20), 3,4-epoxycyclohexyl-(CH2) n-(n is an integer from 2 to 20) and other groups. The cationic polymerizable functional group is preferably a group containing an epoxy group. Particularly preferred groups include: glycidyloxyalkyl, such as glycidyloxypropyl; and epoxycyclohexylalkyl, especially 3,4-epoxycyclohexylethyl. The organopolysiloxane or organosilane of the above-mentioned component (A) can be a linear, branched or cyclic organopolysiloxane or organosilane, and each molecule has an average number of cationic polymerizable functional groups (R) exceeding 1. The following description is based on formula (1) to explain the cationic polymerizable reactive group, and the following description applies to all cationic reactive groups possessed by the component (A) of the present invention.

[0020] Component (A) is preferably composed of the average composition formula:

[0021] R a R' b SiO (4-a-b) / 2 (1)

[0022] (wherein, R is a cationic polymerizable functional group,

[0023] R' is a group selected from a monovalent hydrocarbon group, a hydroxyl group and an alkoxy group other than a cationically polymerizable functional group,

[0024] a and b are numbers satisfying the following conditions: 1≤a+b≤4 and 0.01≤a / (a+b)≤0.5, and the average number of R in the molecule is at least greater than 1. )

[0025] The linear, branched or cyclic organopolysiloxane or organosilane shown.

[0026] The above-mentioned component (A) preferably contains (A1) one or more organopolysiloxanes having two or more cationic polymerizable functional groups in one molecule, and (A2) one or more organosilanes or organopolysiloxanes having one cationic polymerizable functional group in one molecule. Component (A2) only needs to contain at least one of organosilane or organopolysiloxane, so the case where both organosilane and organopolysiloxane are contained as component (A2) is also within the scope of the present invention.

[0027] The above-mentioned component (A1) is preferably selected from the following formula (2):

[0028] [Chemical formula 1]

[0029]

[0030] (In the formula, in all R 1 ~R 8 In the group, each molecule has an average of two or more cationic polymerizable functional groups; other R 1 ~R8 are each independently an unsubstituted or fluorine-substituted monovalent hydrocarbon group; n is a number from 0 to 20),

[0031] From the average unit formula (3):

[0032] (R3SiO 1 / 2 ) c (R2SiO 2 / 2 ) d (RSiO 3 / 2 ) e (SiO 4 / 2 ) f (3)

[0033] (wherein, R is independently a group selected from a cationically polymerizable functional group and a monovalent hydrocarbon group that is unsubstituted or substituted with fluorine, at least two of all R are cationically polymerizable functional groups, (e+f) is a positive number, c is 0 or a positive number, and d is a number in the range of 0 to 10.) an organopolysiloxane,

[0034] From the following formula (4):

[0035] [Chemical formula 2]

[0036]

[0037] (wherein, R is independently a group selected from a cationically polymerizable functional group and a monovalent hydrocarbon group that is unsubstituted or substituted with fluorine, x is an integer of 3 to 10, and the molecule has at least two cationically polymerizable functional groups) a cyclic organopolysiloxane represented by

[0038] and one or more organopolysiloxanes having a cationically polymerizable functional group from the group consisting of a mixture of two or more organopolysiloxanes arbitrarily selected from these.

[0039] The number of cationically polymerizable functional groups in the component (A1) is preferably two per molecule on average.

[0040] Component (A1) may be a linear organopolysiloxane having cationically polymerizable functional groups only at both ends of the molecular chain and having an average number of silicon atoms in the range of 2 to 12.

[0041] The component (A2) is preferably selected from the following formula (2'):

[0042] [Chemical formula 3]

[0043]

[0044] (In the formula, in all R 1 ~R 8In the group, there is only one cationic polymerizable functional group in the molecule; the other R 1 ~R 8 are independently unsubstituted or fluorine-substituted monovalent hydrocarbon groups; n is the viscosity of the polyorganosiloxane represented by formula (2') at 25°C of 1 to 20 mPa·s, and n may be 0) represented by an organopolysiloxane,

[0045] Or by the following formula (4'):

[0046] [Chemical formula 4]

[0047]

[0048] (wherein, R is independently a group selected from a cationically polymerizable functional group and a monovalent hydrocarbon group which is unsubstituted or substituted with fluorine, x is an integer of 3 to 10, and the molecule has only one cationically polymerizable functional group) a cyclic organopolysiloxane represented by

[0049] Or by the following formula (5):

[0050] RSiR'3(5)

[0051] An organosilicon compound having one cationically polymerizable functional group in the molecule, which is a member of the group consisting of organosilanes represented by (wherein R is a cationically polymerizable functional group, and R' is a group selected from a monovalent hydrocarbon group, a hydroxyl group, and an alkoxy group other than the above-mentioned cationically polymerizable functional group).

[0052] The component (A2) is preferably an organopolysiloxane having 3 or more silicon atoms and one cationically polymerizable functional group in the molecule.

[0053] The ratio of the component (A1) to the component (A2) in the ultraviolet curable composition is preferably 10 / 90 to 90 / 10 (A1 / A2; mass ratio).

[0054] The component (B) is preferably a compound that releases a basic substance when heated at 60 to 120°C.

[0055] Component (B) may be a compound comprising a nitrogen-containing cyclic base.

[0056] 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.

[0057] The present invention further provides an insulating coating agent comprising the above-mentioned ultraviolet curable composition. The ultraviolet curable composition of the present invention is useful as an insulating coating agent.

[0058] The present invention further provides a cured product of the ultraviolet curable composition and a method of using the cured product as an insulating coating.

[0059] The present invention further provides a display device including a layer composed of a cured product of the ultraviolet curable composition, such as a liquid crystal display, an organic EL display, and an organic EL flexible display. DETAILED DESCRIPTION

[0060] Hereinafter, the configuration of the present invention will be described in further detail.

[0061] The ultraviolet curable composition of the present invention contains (A) one or more organopolysiloxanes having an average number of more than 1 cationic polymerizable functional groups in one molecule, (B) a compound that releases a basic substance by heating at 60 to 200° C., and (C) a photoacid generator as essential components, and may further contain a component selected from various additives as required. The curable composition of the present invention is characterized in that it does not substantially contain an organic solvent.

[0062] In the present specification, the term "organosilicon compound" is used as a term referring to a concept including organosilane, organosiloxane oligomer, and organopolysiloxane.

[0063] In this specification, the term "polysiloxane" refers to a polysiloxane having a degree of polymerization of siloxane units (Si-O) of 2 or more, that is, a polysiloxane having an average of more than two Si-O bonds per molecule. Polysiloxane includes siloxane oligomers such as disiloxane, trisiloxane, and tetrasiloxane to siloxane polymers with higher degrees of polymerization.

[0064] [Ingredients (A)]

[0065] Component (A) is one or more organopolysiloxanes or organosilanes having an average number of cationic polymerizable functional groups exceeding 1 in one molecule. As long as the purpose can be achieved, the molecular structure can be any structure. The cationic polymerizable functional group having component (A) is preferably a group containing an epoxy group. In the present invention, one or more organopolysiloxanes or organosilanes also include a combination of organopolysiloxanes and organosilanes.

[0066] In one embodiment of the present invention, component (A) is composed of the following average composition formula:

[0067] R a R' b SiO (4-a-b) / 2 (1)

[0068] The linear, branched or cyclic organopolysiloxane or organosilane or a mixture thereof is preferably linear or branched, and particularly preferably linear.

[0069] In formula (1),

[0070] R is a cationic polymerizable functional group,

[0071] R' is a group selected from a monovalent hydrocarbon group, a hydroxyl group and an alkoxy group other than a cationically polymerizable functional group,

[0072] a and b are numbers satisfying the following conditions: 1≤a+b<4 and 0.01≤a / (a+b)≤0.5, preferably 2≤a+b≤3 and 0.05≤a / (a+b)≤0.34.

[0073] The cationically polymerizable functional group represented by R in formula (1) is generally an organic group that can form a cationic intermediate by irradiation with ultraviolet light in the presence or absence of a photoinitiator, thereby forming a bond with each other. In the present invention, it is an arbitrary group that can form a bond in the presence of an acid generated by the photoacid generator of component (C) by irradiation with ultraviolet light or the like. Examples of cationically polymerizable functional groups include: vinyl ether groups, groups containing epoxy groups, groups containing oxetane groups, for example, CH2=CH-O-(CH2)n- (n is an integer from 3 to 20), glycidyloxy-(CH2) n -(n is an integer from 3 to 20), 3,4-epoxycyclohexyl-(CH2) n - (n is an integer from 2 to 20) and the like.

[0074] The cationic polymerizable functional group is preferably a group containing an epoxy group. Particularly preferred groups include: glycidyloxyalkyl, such as glycidyloxypropyl; and epoxycyclohexylalkyl, especially 3,4-epoxycyclohexylethyl. The linear, branched or cyclic organopolysiloxane or organosilane represented by the above average composition formula has an average number of more than 1 cationic polymerizable functional group (R) per molecule.

[0075] R' is a monovalent hydrocarbon group, including unsubstituted monovalent hydrocarbon groups and monovalent hydrocarbon groups substituted by fluorine. The unsubstituted or fluorine-substituted monovalent hydrocarbon group is preferably a group selected from an unsubstituted or fluorine-substituted alkyl group, a cycloalkyl group, an arylalkyl group and an aryl group having 1 to 20 carbon atoms. As the above-mentioned alkyl group, groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, pentyl, and octyl can be listed, but methyl is particularly preferred. As the above-mentioned cycloalkyl group, cyclopentyl, cyclohexyl, etc. can be listed. As the above-mentioned arylalkyl group, benzyl, phenethyl, etc. can be listed. As the above-mentioned aryl group, phenyl, naphthyl, etc. can be listed. As examples of monovalent hydrocarbon groups substituted by fluorine, 3,3,3-trifluoropropyl and 3,3,4,4,5,5,6,6,6-nonafluorohexyl can be listed. As a monovalent hydrocarbon group substituted by fluorine, 3,3,3-trifluoropropyl is preferred. R' is not essentially a cationically polymerizable functional group.

[0076] The viscosity of the component (A) represented by the above formula (1) at 25°C is 1 to 1000 mPa·s, 5 to 500 mPa·s or 10 to 100 mPa·s, and most preferably 10 to 50 mPa·s. The viscosity of the organopolysiloxane or organosilane can be adjusted by changing the ratio and molecular weight of a and b in formula (1).

[0077] The component (A) preferably has an average of 1.1 to 20, more preferably 1.2 to 12, and particularly preferably 1.3 to 12 silicon atoms per molecule.

[0078] In a preferred embodiment, component (A) contains: (A1) one or more organopolysiloxanes having an average of two or more cationic polymerizable functional groups in one molecule and (A2) one or more organosilanes or organopolysiloxanes having one cationic polymerizable functional group in one molecule. In the present invention, the one or more organosilanes or organopolysiloxanes include the case where an organosilane and an organopolysiloxane are used in combination. Thus, the crosslinking density of the obtained organopolysiloxane cured product can be controlled, and the ability to adjust various physical properties can be improved. Specifically, component (A2) improves the flexibility of the cured product obtained from the present composition and is effective for the design of an organopolysiloxane with a large tensile elongation.

[0079] The above-mentioned component (A1) can be represented by the following formula (2):

[0080] [Chemical formula 5]

[0081]

[0082] (In the formula, in all R 1 ~R 8 In the group, each molecule has an average of two or more cationic polymerizable functional groups; other R 1 ~R8 An organopolysiloxane represented by (wherein each independently is an unsubstituted or fluorine-substituted monovalent hydrocarbon group; and n is a number from 0 to 20).

[0083] In formula (2), in all R 1 ~R 8 In the group, an average of two or more per molecule are cationically polymerizable functional groups. As the cationically polymerizable functional group, the functional group described in the above formula (1) can be used. In addition, R other than the cationically polymerizable functional group 1 ~R 8 Each is independently an unsubstituted or fluorine-substituted monovalent hydrocarbon group, preferably a group selected from an unsubstituted or fluorine-substituted alkyl group, cycloalkyl group, aralkyl group and aryl group having 1 to 20 carbon atoms. Similarly, the functional groups described in the above formula (1) can be used.

[0084] The number of cationically polymerizable functional groups possessed by the organopolysiloxane of formula (2) as component (A1) is 2 to 6, preferably 2 to 5, more preferably 2 to 4, particularly preferably 2 to 3, and most preferably 2 per molecule on average.

[0085] In particular, it is preferred that R in formula (2) 1 ~R 3 One of the 6 ~R 8 Furthermore, it is particularly preferred that R in formula (2) 1 ~R 3 One of the 6 ~R 8 Only one of them is a cationically polymerizable functional group.

[0086] n in formula (2) is a value at which the viscosity of the organopolysiloxane represented by formula (2) at 25°C is preferably 1 to 1000 mPa·s, more preferably 5 to 500 mPa·s, particularly preferably 10 to 100 mPa·s, and most preferably 10 to 50 mPa·s. A person skilled in the art can easily determine the value of n without excessive trial and error in such a manner that the viscosity of the organopolysiloxane of formula (2) is within the above viscosity range. However, in general, in order to make the compound of formula (2) have a desired viscosity, the number of silicon atoms per molecule is preferably 2 to 12, particularly preferably 2 to 10.

[0087] The organopolysiloxane of formula (2) can be used alone or as a mixture of two or more. When two or more organopolysiloxanes are used as a mixture, the viscosity of the mixture at 25° C. is preferably the above-mentioned viscosity.

[0088] The compound of the component (A1) may be an organopolysiloxane represented by the following average unit formula (3).

[0089] Average unit formula (3):

[0090] (R3SiO 1 / 2 ) c (R2SiO 2 / 2 ) d (RSiO 3 / 2 ) e (SiO 4 / 2 ) f (3)

[0091] In formula (3), R is independently a group selected from a cationically polymerizable functional group and a monovalent hydrocarbon group which is unsubstituted or substituted by fluorine, at least two of all R are cationically polymerizable functional groups, (e+f) is a positive number, a is 0 or a positive number, and b is a number in the range of 0 to 10.

[0092] The cationically polymerizable functional group and the monovalent hydrocarbon group are the same as those defined in the above formula (1). The preferred viscosity of the organopolysiloxane represented by formula (3) is also the same as that defined for the organopolysiloxane represented by formula (1).

[0093] The number of ultraviolet curable functional groups possessed by the organopolysiloxane represented by the formula (3) is preferably 2 to 5, more preferably 2 to 4, particularly preferably 2 to 3, and most preferably two per molecule.

[0094] The organopolysiloxane represented by the formula (3) preferably has 3 to 20, more preferably 3 to 12, and particularly preferably 5 to 12 silicon atoms per molecule.

[0095] Specific examples of the above-mentioned component (A1), in particular the organopolysiloxane represented by formula (2) or (3), include: 1,3-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3-tetramethyldisiloxane, 1,5-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5-hexamethyltrisiloxane, 1,7-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5,7,7-octamethyltetrasiloxane, 1,9-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5,7,7-octamethyltetrasiloxane, Bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5,7,7,9,9-decamethylpentasiloxane, methyl(tris[2-(3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, tetrakis[2-(3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, 1,3-(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, 1,5-bis(3-glycidoxypropyl)-1,1,3,3,5,5-hexamethyltrisiloxane oxane, 1,7-bis(3-glycidoxypropyl)-1,1,3,3,5,5,7,7-octamethyltetrasiloxane, 1,9-bis(3-glycidoxypropyl)-1,1,3,3,5,5,7,7,9,9-decamethylpentasiloxane, (3,4-epoxycyclohexylethyldimethylsilyl)-polydimethylsiloxane at both ends, (3-glycidoxypropyldimethylsilyl)-polydimethylsiloxane at both ends, trimethylsilyl-dimethylsiloxy / (methyl- 3,4-epoxycyclohexylethylsilyloxy) copolymer, trimethylsilyl-dimethylsilyloxy / (methyl-3-glycidoxypropylsilyloxy) copolymer at both ends, (3,4-epoxycyclohexylethyldimethylsilyloxy)-dimethylsilyloxy / (methyl-3,4-epoxycyclohexylethylsilyloxy) copolymer at both ends, (3-glycidoxypropyldimethylsilyl)-dimethylsilyloxy / (methyl-3-glycidoxypropylsilyloxy) copolymer at both ends.

[0096] In addition, the compound of the component (A1) may also be represented by the following formula (4):

[0097] [Chemical formula 6]

[0098]

[0099] (wherein, R is independently a group selected from a cationically polymerizable functional group and a non-substituted or fluorine-substituted monovalent hydrocarbon group, x is an integer of 3 to 10, and the molecule has at least two cationically polymerizable functional groups).

[0100] The cationically polymerizable functional group and the unsubstituted or fluorine-substituted monovalent hydrocarbon group which may be represented by R in formula (4) are the same as those defined in formula (1).

[0101] The preferred viscosity of the organopolysiloxane represented by the formula (4) is also the same as that defined above for the organosilicon compound represented by the formula (1).

[0102] Specific examples of the cyclic organopolysiloxane represented by formula (4) include: 1,3,5-trimethyl-1,3,5-tris[2-(3,4-epoxycyclohexyl)ethyl]cyclotrisiloxane, 1,3,5-trimethyl-1,3,5-tris(3-glycidoxypropyl)cyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetra[2-(3,4-epoxycyclohexyl)ethyl]cyclotrisiloxane, )ethyl] cyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetra(3-glycidoxypropyl)cyclotetrasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-penta[2-(3,4-epoxycyclohexyl)ethyl]cyclopentasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-penta(3-glycidoxypropyl)cyclopentasiloxane.

[0103] The organopolysiloxanes represented by the above formulae (2) to (4) may be used alone or in any combination of two or more thereof as the component (A1).

[0104] As the component (A1), it is particularly preferred to use one or more organopolysiloxanes selected from the group consisting of the linear organopolysiloxane represented by the above formula (2), the cyclic organopolysiloxane represented by the formula (4), and a combination thereof.

[0105] Component (A1) is particularly preferably a linear organopolysiloxane having only cationically polymerizable functional groups at both ends of the molecular chain and having an average number of silicon atoms of 2 to 12, and particularly preferably a linear dimethylpolysiloxane having epoxy-containing groups at both ends of the molecular chain.

[0106] The compound recommended as component (A1) is one compound selected from the group consisting of 1,3-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3-tetramethyldisiloxane, 1,5-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5-hexamethyltrisiloxane, 1,9-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5,7,7,9,9-decamethylpentasiloxane, methyl(tris[2-(3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, tetrakis([2-(3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, and polydimethylsiloxane having (3,4-epoxycyclohexylethyldimethylsilyl) groups at both ends, or a combination of two or more compounds. Among them, 1,3-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3-tetramethyldisiloxane, 1,5-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5-hexamethyltrisiloxane, and 1,9-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5,7,7,9,9-decamethylpentasiloxane can be particularly preferably used.

[0107] The above-mentioned component (A2) is an organosilicon compound having one cationic polymerizable functional group in one molecule in an organosilane or organopolysiloxane skeleton. The component (A2) mainly has the following effects: controlling the crosslinking density of the cured product obtained from the composition of the present invention, adjusting the physical properties of the cured product, and reducing the viscosity of the composition.

[0108] The component (A2) is preferably selected from the following formula (2'):

[0109] [Chemical formula 7]

[0110]

[0111] (In the formula, in all R 1 ~R 8 In the group, there is only one cationic polymerizable functional group in the molecule; the other R 1 ~R 8 are independently unsubstituted or fluorine-substituted monovalent hydrocarbon groups; n is the viscosity of the (poly)organosiloxane represented by formula (2') at 25°C of 1 to 20 mPa·s, and n can be 0) represented by the organopolysiloxane,

[0112] Or by the following formula (4'):

[0113] [Chemical formula 8]

[0114]

[0115] (wherein, R is independently a group selected from a cationically polymerizable functional group and a monovalent hydrocarbon group which is unsubstituted or substituted with fluorine, x is an integer of 3 to 10, and the molecule has only one cationically polymerizable functional group) a cyclic organopolysiloxane represented by

[0116] Or by the following formula (5):

[0117] RSiR'3(5)

[0118] An organosilicon compound having one cationically polymerizable functional group in the molecule, which is a member of the group consisting of organosilanes represented by (wherein R is a cationically polymerizable functional group, and R' is a group selected from a monovalent hydrocarbon group, a hydroxyl group, and an alkoxy group other than the above-mentioned cationically polymerizable functional group).

[0119] R of the organopolysiloxane represented by formula (2') 1 ~R 8 In the group, there is one cationically polymerizable functional group per molecule. As the cationically polymerizable functional group, the functional group described in the above formula (1) can be used. In addition, R other than the cationically polymerizable functional group 1 ~R 8 Each is independently an unsubstituted or fluorine-substituted monovalent hydrocarbon group, preferably a group selected from an unsubstituted or fluorine-substituted alkyl group, cycloalkyl group, aralkyl group and aryl group having 1 to 20 carbon atoms. Similarly, the functional groups described in the above formula (1) can be used.

[0120] There is no particular restriction on the position of the cationic polymerizable functional group in the organopolysiloxane represented by formula (2'), and it may be a terminal substituent of the molecular chain, for example, R 1 ~R 3 One of the groups can also be a side chain substituent, that is, R 4 or R 5 Group.

[0121] The viscosity of the organosilicon compound represented by the formula (2') at 25° C. is preferably 1 to 20 mPa·s, more preferably 2 to 10 mPa·s. The viscosity of the organosilicon compound can be adjusted by changing the value of n in the formula (2') which is a numerical value of 0 or more.

[0122] The organosilicon compound represented by the above formula (2') is preferably a compound having 1 to 10, preferably 2 to 4 silicon atoms per molecule.

[0123] In the substituent R of the cyclic organopolysiloxane represented by the formula (4'), there is one cationically polymerizable functional group per molecule. As the cationically polymerizable functional group and other groups, the functional groups described in the above formula (1) can be used.

[0124] The preferred viscosity of the cyclic organopolysiloxane represented by the formula (4') is also the same as that defined for the organosilicon compound represented by the formula (1).

[0125] The cationically polymerizable functional group R of the organosilane represented by formula (5) is the same as that of the organosilicon compound represented by formula (1). In addition, the other groups R' are groups selected from monovalent hydrocarbon groups, hydroxyl groups and alkoxy groups other than the cationically polymerizable functional group, and the functional groups described in formula (1) can be used.

[0126] The organopolysiloxane or organosilane represented by the above formula (2'), (4') and (5) can be used alone or in any combination of two or more thereof as the component (A2).

[0127] As the component (A2), it is particularly preferred to use one or more organopolysiloxanes selected from the group consisting of the linear organopolysiloxane represented by the above formula (2'), the cyclic organopolysiloxane represented by the formula (4'), and a combination thereof.

[0128] Component (A2) is particularly preferably a linear organopolysiloxane having one cationically polymerizable functional group and having an average silicon atom number of 2 to 5, particularly 3 to 5, and particularly preferably a linear polysiloxane in which all substituents other than the cationically polymerizable functional group are methyl groups.

[0129] Specific examples of the organopolysiloxane having one cationically polymerizable functional group in the molecule of the component (A2) include 1-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,3-pentamethyldisiloxane, 1-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5,5-heptamethyltrisiloxane, 3-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,1,3,5,5,5-heptamethyltrisiloxane, 1-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5,7,7,7-nonamethyltetrasiloxane, 1-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5,7,7,7-nonamethyltetrasiloxane, and 1-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5,7,7,7-nonamethyltetrasiloxane. 1-(3-glycidoxypropyl)-1,1,3,3,3-pentamethyldisiloxane, 1-(3-glycidoxypropyl)-1,1,3,3,5,5,5-heptamethyltrisiloxane, 3-(3-glycidoxypropyl)-1,1,1,3,5,5,5-heptamethyltrisiloxane, 1-(3-glycidoxypropyl)-1,1,3,3,5,5,7,7,7-nonamethyltetrasiloxane, 1-[2-(3,4-epoxycyclohexyl)ethyl]1,3,3,5,5,7,7-heptamethylcyclotetrasiloxane, 1-(3-glycidoxypropyl)-1,3,3,5,5,7,7-heptamethylcyclotetrasiloxane.

[0130] Component (A1) and component (A2) can be used in any mass ratio, but relative to the total amount 100 mass % of component (A1) and component (A2), the ratio of component (A1) is 10 mass % or more and 90 mass % or less, preferably 30 mass % or more and 80 mass % or less, more preferably 40 mass % or more and 70 mass % or less. In other words, the ratio of component (A2) is 10 mass % or more and 90 mass % or less, preferably 20 mass % or more and 70 mass % or less, more preferably 30 mass % or more and 60 mass % or less. In the case of this scope, the viscosity of the curable composition can be made appropriate, and the mechanical properties, dielectric properties, etc. of the cured product obtained can be easily adjusted as the desired properties of the insulating coating material.

[0131] [Ingredient (B)]

[0132] Component (B) is a compound that releases a basic substance when heated at 60 to 200° C. and is a component useful for improving the outgassing characteristics of the cured product obtained from the ultraviolet curable composition of the present invention, that is, reducing outgassing.

[0133] The component (B) of the present invention can suppress the unintended reaction of the ultraviolet curable composition of the present invention in the presence of an acidic compound generated by the photoacid generator of the component (C) as a curing catalyst at high temperatures, for example, 60 to 200° C., particularly 80 to 150° C., thereby reducing the amount of gas generated. More specifically, the component (B) can preferably use a compound that releases more than 10 mol% of alkaline molecules equivalent to its use amount by heating for 30 minutes within the above temperature range, and can use a specific compound described later. The amount of alkaline molecules released can be determined by a known measurement method such as an acid-base titration method.

[0134] As component (B), compounds with various structures known to dissociate and / or decompose within a specified temperature range to release alkaline substances can be used. In the present invention, as long as it is a compound that can release alkaline substances at high temperatures, specifically at 60 to 200°C, its structure is not particularly limited, and any compound selected from such a compound group can be used. As component (B), for example, compounds commercially available as thermal base generators can be listed, preferably organic acid salts of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and / or 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) known as U-CAT SA (registered trademark) and U-CAT (registered trademark) series, preferably, the active temperature is in the range of 60°C to 200°C.

[0135] Specific examples of the compound that can be used as component (B) include N-(2-nitrobenzyloxycarbonyl)imidazole, N-(3-nitrobenzyloxycarbonyl)imidazole, N-(4-nitrobenzyloxycarbonyl)imidazole, N-(5-methyl-2-nitrobenzyloxycarbonyl)imidazole, N-(4-chloro-2-nitrobenzyloxycarbonyl)imidazole, 1-(p-methoxycinnamoyl)imidazole, 1-(o-nitro-p-methoxy)imidazole, imidazole derivatives such as cinnamoyl) imidazole; ethyl formate such as 1-methyl-1-(4-biphenyl) carbamate and 2-cyano-1,1-dimethyl carbamate; ureas such as urea, N,N-dimethyl-N'-methylurea, 1,1'-(4-methyl-1,3-phenylene)bis(3,3-dimethylurea); guanidines such as trichloroacetic acid guanidine, benzenesulfonyl acetate, and guanidine phenylpropionate; 1,4-dihydronicotinoyl dihydropyridines such as amines; dimethyl piperidines such as N-(isopropoxycarbonyl)-2,6-dimethylpiperidine, N-(tert-butoxycarbonyl)-2,6-dimethylpiperidine, and N-(benzyloxycarbonyl)-2,6-dimethylpiperidine; quaternary ammonium salts such as tetramethylammonium benzenesulfonyl acetate and tetramethylammonium benzenepropionate; amino ketones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one; cyclic amidine compounds Organic acid salts, for example, DBU salts of organic acids such as phenol salt of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), ethylhexanoate of 1,8-diazabicyclo[5.4.0]undec-7-ene; DBN salts of organic acids such as ethylhexanoate of 1,5-diazabicyclo[4.3.0]non-5-ene (DBN); triphenylphosphine derivative salts such as benzyltriphenylphosphonium bromide; dicyandiamide, etc. It should be noted that in the present invention, the "organic acid" related to component (B) refers to any organic compound having an acidic group, and the structure of the acidic group is not particularly limited, but carboxyl group and phenolic hydroxyl group are particularly preferred.

[0136] Furthermore, as component (B), if the miscibility with component (A), storage stability and alkalinity are taken into consideration, a compound containing a nitrogen-containing cyclic base is preferred. Specifically, the organic acid salts of the above-mentioned imidazole derivatives, piperidine derivatives, and cyclic amidine compounds, such as DBU salts of organic acids and DBN salts of organic acids, are a preferred compound group. Among them, DBU salts of organic acids and DBN salts of organic acids can be particularly preferably used. In this case, the organic acid is preferably selected from organic carboxylic acids, especially alkyl carboxylic acids, and especially C1-C 20 Alkyl carboxylic acids, especially C6-C 18 Organic acids from the group consisting of alkyl carboxylic acids, aromatic carboxylic acids such as phthalic acid, aromatic sulfonic acids such as p-toluenesulfonic acid, and aromatic compounds having a phenolic hydroxyl group such as phenols or novolac resins, especially unsubstituted or alkyl-substituted phenols, and combinations of trimellitic acid and phenolic resins.

[0137] As the component (B), a compound group that releases a basic substance when heated in a temperature range of 60 to 120°C is preferred, and a compound group whose temperature range is 80 to 120°C is more preferred.

[0138] The preferred usage amount of component (B) of the present invention is 0.01 to 5% by mass relative to 100% by mass of the ultraviolet curable composition. This is because, when it is less than the above lower limit, the exhaust suppression effect is almost invisible, and on the other hand, when the usage amount is above the upper limit above the above conditions, the ultraviolet curability of the present composition is adversely affected. Relative to 100% by mass of the curable composition, component (B) is preferably in the range of 0.1 to 1% by mass.

[0139] On the other hand, the preferred amount of component (B) used in the ultraviolet curable composition depends on the structure and molecular weight of the photoacid generator of component (C) described below. As described above, in order to suppress the influence on the ultraviolet curability of the present composition, the stoichiometric amount of component (B) is preferably less than the stoichiometric amount of component (C), preferably less than 80 mol% of the stoichiometric amount of component (C), more preferably less than 60 mol%, and more preferably less than 50 mol%.

[0140] [Ingredient (C)]

[0141] In the ultraviolet curable composition of the present invention, in addition to the above-mentioned components (A) and (B), a component (C): a photoacid generator is added. It is known that component (C) is a kind of photocationic polymerization initiator, and generates a Bronsted acid or a Lewis acid by irradiation with ultraviolet rays, and the acid causes a reaction between cationic polymerizable functional groups.

[0142] The photoacid generator used in the curable composition of the present invention can be arbitrarily selected from the photoacid generators known in the art and is not particularly limited to a specific photoacid generator. Among the photoacid generators, strong acid generating compounds such as diazonium salts, sulfonium salts, iodonium salts, and phosphonium salts are known, and one or more selected from these compounds can be used. Examples of photoacid generators include: bis(4-tert-butylphenyl)iodonium hexafluorophosphate, cyclopropyldiphenylsulfonium tetrafluoroborate, dimethylphenacylmethylsulfonium tetrafluoroborate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, diphenyliodonium tetrafluoromethanesulfonate, 2-(3,4-dimethoxyphenylvinyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(furan-2-yl)vinyl]-4, 6-bis(trichloromethyl)-1,3,5-triazine, 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-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5 -triazine, 4-nitrobenzene diazonium tetrafluoroborate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium bromide, tri-p-tolylsulfonium hexafluorophosphate, tri-p-tolylsulfonium trifluoromethanesulfonate, diphenyliodonium trifluoromethanesulfonate, triphenylsulfonium trifluoromethanesulfonate, diphenyliodonium nitrate, bis(4-tert-butylphenyl)iodonium perfluoro-1-butanesulfonate, bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, triphenylsulfonium perfluoro-1-butanesulfonate, N-hydroxy Naphthalimide trifluoromethanesulfonate, p-toluenesulfonate, diphenyliodonium p-toluenesulfonate, (4-tert-butylphenyl)diphenylsulfonium trifluoromethanesulfonate, tris(4-tert-butylphenyl)sulfonium trifluoromethanesulfonate, N-hydroxy-5-norbornene-2,3-dicarboximide perfluoro-1-butylsulfonate, (4-phenylthiophenyl)diphenylsulfonium trifluoromethanesulfonate, and 4-(phenylthio)phenyldiphenylsulfonium triethyl trifluorophosphate, etc., but are not limited thereto. Examples of the photocationic polymerization initiator include, in addition to the above compounds, commercially available photoinitiators such as Omnicat 250, Omnicat 270 (from IGM Resins BV), CPI-310B, IK-1 (from San-Apro Co., Ltd.), DTS-200 (from Midori Chemical Co., Ltd.), and Irgacure 290 (from BASF).

[0143] The amount of the photoacid generator added to the curable composition of the present invention is not particularly limited as long as the intended photocuring reaction occurs, but is usually preferably used in an amount of 0.1 to 10% by mass, preferably 0.2 to 5% by mass, and particularly 0.5 to 4% by mass, relative to 100% by mass of the composition of the present invention.

[0144] In the present invention, as a polymerization initiator, in addition to the above-mentioned photoacid generator, the photosensitizer described below can also be used. It is known that the use of a sensitizer can improve the photopolymerization and curing reaction quantum efficiency, and compared with the case of using only a photoacid generator, it becomes possible to use longer wavelength light in the polymerization reaction, so it is particularly effective when the coating thickness of the composition is thicker or when a longer wavelength LED light source is used. As a sensitizer, it is known that there are: anthracene compounds, phenothiazine compounds, perylene compounds, anthocyanin compounds, merocyanine compounds, coumarin compounds, benzylidene ketone compounds, (thio) xanthene or (thio) xanthone compounds, such as isopropyl thioxanthone, 2,4-diethyl thioxanthone, alkyl substituted anthracene, squarylium compounds, (thio) pyrylium compounds, porphyrin compounds, etc., but are not limited to these, and any photosensitizer can be used for the curable composition of the present invention.

[0145] [Overall viscosity of the composition]

[0146] The curable composition of the present invention can be used as a coating agent. In order to have fluidity and workability suitable for applying the composition to a substrate, the viscosity of the entire composition is measured using an E-type viscometer and is 500 mPa·s or less at 25°C. The preferred viscosity range is 5 to 80 mPa·s, more preferably 5 to 50 mPa·s, and particularly preferably 5 to 30 mPa·s. In order to adjust the viscosity of the entire curable composition to the desired viscosity, compounds with preferred viscosities can be used as each component so that the viscosity of the entire composition has the desired viscosity.

[0147] [No use of organic solvents]

[0148] The ultraviolet curable composition of the present invention is a composition that can achieve a viscosity suitable for the above-mentioned coating agent by using the above-mentioned components without using an organic solvent. In this specification, the organic solvent is substantially not included, which means that the content of the organic solvent is less than 0.05% by mass of the entire composition, preferably below the analytical limit using an analytical method such as gas chromatography. In the present invention, by adjusting the molecular structure and molecular weight of component (A), component (B) and component (C), the desired viscosity can be achieved even without using an organic solvent.

[0149] The cured product obtained by the curable composition of the present invention can obtain the desired physical properties of the cured product and the curing speed of the curable composition according to the molecular chain length of component (A), the position of the cationic polymerizable functional group in the molecule, the molecular structure and the number of cationic polymerizable functional groups per molecule, and the viscosity of the curable composition is designed to the desired value. In addition, the cured product obtained by curing the curable composition of the present invention is also included in the scope of the present invention. Further, the shape of the cured product obtained by the composition of the present invention is not particularly limited, and can be a film-like coating, or a sheet-like molding, or it can be injected into a specific position in an uncured state to cure it, forming a filler, and it can also be used as a sealing material, an intermediate layer of a laminate or a display device, etc. The cured product obtained by the composition of the present invention is particularly preferably in the form of a film-like coating, and is particularly preferably an insulating coating.

[0150] The curable composition of the present invention is suitable for use as a coating agent or a potting agent, particularly as an insulating coating agent or a potting agent for electronic devices and electric equipment.

[0151] The cured product obtained by curing the curable composition of the present invention has excellent mechanical properties and its adjustment ability, and has low dielectric properties. The elastic modulus measured at 25°C is usually 200MPa or more, and the value of the relative dielectric constant is usually 3.0 or less. According to expectations, the cured product obtained by curing the curable composition of the present invention can be designed to have a relative dielectric constant of 2.7 or less, and the curable composition of the present invention can also be used to form a coating with a low relative dielectric constant.

[0152] On the other hand, the curable composition of the present invention can also design materials with large tensile elongation. Using a test body with a thickness of 0.5 mm, the tensile elongation is usually more than 10% when evaluated at a tensile speed of 50 mm / min at 25°C. By optimizing the curable composition, the tensile elongation of the cured product can be made to reach more than 50%. Taking advantage of this characteristic, it is also useful as a layer forming material for flexible displays.

[0153] [Other additives]

[0154] In the composition of the present invention, other additives can be added as desired. As the additive that can be used, there can be listed: leveling agent, various adhesion imparting agents, silane coupling agents other than these, ultraviolet light absorbers, antioxidants, polymerization inhibitors, fillers (functional fillers such as reinforcing fillers, insulating fillers and thermal conductive fillers), etc. As required, suitable additives can be added to the composition of the present invention. In addition, in the composition of the present invention, as required, particularly in the case of being used as a potting agent or a sealing material, a thixotropic imparting agent can also be added. In particular, in the composition of the present invention, the following tackifier can be and preferably added arbitrarily.

[0155] [Thickener]

[0156] In the composition of the present invention, in order to improve the adhesion and closeness relative to the base material in contact with the composition, an adhesion promoter can be added. In the case where the curable composition of the present invention is used for the purposes of coating agents, sealing materials, etc. that require adhesion or closeness relative to the base material, it is preferred to add a tackifier in the curable composition of the present invention. As the adhesion promoter, any known adhesion promoter can be used as long as the curing reaction of the composition of the present invention is not hindered.

[0157] Examples of adhesion promoters that can be used in the present invention include: organic silanes having a trialkoxysilyloxy group (e.g., trimethoxysilyloxy group, triethoxysilyloxy 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 organic siloxane oligomers having a linear structure, a branched structure, or a cyclic structure having about 4 to 20 silicon atoms; organic silanes having a trialkoxysilyloxy group or a trialkoxysilylalkyl group and a methacryloxyalkyl group (e.g., 3-methacryloxypropyl group); alkyl) or an organosiloxane oligomer having a linear structure, branched structure or cyclic structure with about 4 to 20 silicon atoms; an organosilane having a trialkoxysilyloxy group or a trialkoxysilylalkyl group and an epoxy-bonded alkyl group (for example, a 3-glycidoxypropyl group, a 4-glycidoxybutyl group, a 2-(3,4-epoxycyclohexyl)ethyl group, a 3-(3,4-epoxycyclohexyl)propyl group), or an organosiloxane oligomer having a linear structure, branched structure or cyclic structure with about 4 to 20 silicon atoms; an organosilane having two or more trialkoxysilyl groups (for example, a trimethoxysilyl group) or a 2-(3,4-epoxycyclohexyl)ethyl group, a 2-(3,4-epoxycyclohexyl)ethyl group, a 2-(3,4-epoxycyclohexyl)propyl group, or an organosiloxane oligomer having a linear structure, branched structure or cyclic structure with about 4 to 20 silicon atoms; , triethoxysilyl) organic compounds; reactants of aminoalkyltrialkoxysilyl and epoxy-bonded alkyltrialkoxysilyl, epoxy-containing ethyl polysilicates, specifically, 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, a reaction product of 3-glycidoxypropyltriethoxysilane and 3-aminopropyltriethoxysilane, a condensation reaction product of a silanol-terminated methylvinylsiloxane oligomer and 3-glycidoxypropyltrimethoxysilane, a condensation reaction product of a silanol-terminated methylvinylsiloxane oligomer and 3-methacryloxypropyltriethoxysilane, and tris(3-trimethoxysilylpropyl)isocyanurate.

[0158] The amount of the adhesion promoter added to the curable composition of the present invention is not particularly limited, but is preferably in the range of 0.01 to 5 mass parts, or in the range of 0.01 to 2 mass parts, relative to 100 mass parts of the curable composition, from the perspective of the curing characteristics of the curable composition and not promoting discoloration of the cured product.

[0159] [use]

[0160] The ultraviolet curable organopolysiloxane composition of the present invention can be cured not only by ultraviolet rays but also by electron beams, which is also one embodiment of the present invention.

[0161] The curable composition of the present invention is low-viscosity, and is particularly useful as a material for forming an insulating layer constituting various articles, particularly electronic devices and electrical equipment. The composition of the present invention can be applied to a substrate, or at least one side can be clamped by two substrates composed of a material for ultraviolet rays or electron beams to pass through, and the composition is irradiated with ultraviolet rays or electron beams, thereby curing the composition to form an insulating layer. In this case, it is also possible to form a pattern when the composition of the present invention is applied to a substrate, and then the composition is cured. In addition, the composition can also be applied to a substrate, and when it is cured, a portion and an uncured portion cured by the irradiation of ultraviolet rays or electron beams remain, and then the uncured portion is removed by a solvent, thereby forming an insulating layer of a desired pattern. In particular, when the cured layer involved in the present invention is an insulating layer, it can be designed in a manner with a low relative dielectric constant less than 3.0.

[0162] As for the curable composition of the present invention, the cured product obtained therefrom has good transparency, and is therefore particularly suitable as a material for forming an insulating layer of a display device such as a touch panel and a display. In this case, the insulating layer can also be formed into a desired optional pattern as described above as needed. Therefore, a display device such as a touch panel and 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.

[0163] In addition, after applying the curable composition of the present invention to an article, it is cured to form an insulating coating (insulating film). Therefore, the composition of the present invention can be used as an insulating coating agent. In addition, the cured product formed by curing the curable composition of the present invention can also be used as an insulating coating.

[0164] The insulating film formed by the curable composition of the present invention can be used for various purposes. In particular, it can be used as a component of an electronic device, or can be used 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 a semiconductor device, such as LSI (Large Scale Integration), system LSI, DRAM (Dynamic Random Access Memory), SDRAM (Synchronous Dynamic Random Access Memory), RDRAM (Rambus Dynamic Random Access Memory), D-RDRAM (Direct Rambus Dynamic Random Access Memory) and multi-chip module (Multichip Module) multilayer wiring board insulation coating, semiconductor interlayer insulation film, etching stopper (Etching Stopper) film, surface protection film, buffer coating, passivation film in LSI, cover coat of flexible copper clad board, solder resist film, surface protection film for optical device.

[0165] Furthermore, the ultraviolet curable composition of the present invention can be suitably used as a potting agent in addition to a coating agent, and is particularly suitably used as an insulating potting agent for electronic devices and electric equipment.

[0166] The composition of the present invention can be particularly used as a material for forming a coating layer on a substrate surface using an inkjet printing method.

[0167] Hereinafter, the present invention will be further described based on examples, but the present invention is not limited to the following examples.

[0168] Example

[0169] The ultraviolet curable composition of the present invention and its cured product will be described in detail by way of examples. The measurements and evaluations in the examples and comparative examples were performed as follows.

[0170] [Viscosity of curable composition]

[0171] The viscosity (mPa·s) of the composition at 25° C. was measured using a rotational viscometer (manufactured by TOKIMEC CORPORATION, E-type viscometer VISCONIC EMD).

[0172] [Appearance of the curable composition and the cured product obtained therefrom]

[0173] The appearance of the curable composition and the cured product obtained therefrom were visually observed and evaluated.

[0174] [Preparation of curable composition]

[0175] The respective materials in the amounts described in the following Table 1 were placed in a brown plastic container and thoroughly mixed using a planetary mixer to prepare a curable composition.

[0176] [Curing of Curable Composition and Measurement of Outgassing]

[0177] On a PET film coated with a fluoropolymer release agent, a coating layer of the curable composition was prepared by spin coating. 2 The composition was cured by irradiating LED light with a wavelength of 405 nm with energy to produce a cured coating with a thickness of 8 μm. The obtained coating was peeled off from the film, and 5 to 10 mg was weighed and put into a specified vial. After heating the cured sample under the following two conditions, the gas (unit ppm) generated by heating was analyzed and quantified by headspace gas chromatography.

[0178] <Condition 1> Maintain at 110°C for 30 minutes

[0179] <Condition 2> Maintain at 130°C for 30 minutes

[0180] [Curing of curable composition and preparation of viscoelasticity test piece]

[0181] About 0.5 g of the curable composition was injected between two glass substrates sandwiched by a 1 mm thick spacer. The curable composition was injected through one of the glass substrates from the outside at a rate of 2 J / cm 2 The composition was cured by irradiating LED light with a wavelength of 405 nm to produce a strip-shaped cured product with a long side of 50 mm, a short side of 10 mm, and a thickness of 1 mm.

[0182] [Determination of elastic modulus of cured organopolysiloxane]

[0183] The strip test piece made of the organopolysiloxane cured product was used to measure the dynamic viscoelasticity of the sample using a dynamic viscoelasticity measuring apparatus MCR-302 manufactured by Anton Paar at a frequency of 1 Hz, a strain of 0.1%, and a stress of -0.1 N / mm 2 Under the conditions of a heating rate of 3°C / min, the viscoelasticity measurement was performed in a temperature range of -40°C to 160°C, and the storage modulus value (unit: MPa) at 25°C was recorded.

[0184] [Curing of Curable Composition and Preparation of Sample for Measurement of Relative Dielectric Constant]

[0185] A mold with a thickness of 1 mm and 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 the curable composition was poured into the hole. The same PET film as described above was covered on the composition, and a glass plate with a thickness of 10 mm was further placed on it. 2 The composition was cured by irradiating LED light having a wavelength of 405 nm with energy of 100 nm to prepare a disk-shaped organopolysiloxane cured product having a diameter of 40 mm and a thickness of 1 mm.

[0186] [Relative dielectric constant of cured organopolysiloxane]

[0187] On the organopolysiloxane cured product produced, a tin foil with a diameter of 33mm and a thickness of 0.007mm was crimped on both sides. In order to improve the adhesion of the cured product and the foil, a trace amount of silicone oil can be crimped as required. The E4990A precision impedance analyzer (PrecisionImpedance Analyzer) manufactured by Keysight Technologies, which is connected to a parallel plate electrode with a diameter of 30mm, was used to measure the electrostatic capacity at room temperature and 100KHz. The relative dielectric constant was calculated using the value of the electrostatic capacity measured, the thickness of the cured product measured in addition, and the value of the electrode area.

[0188] [Examples and Comparative Examples]

[0189] Using the following components, ultraviolet curable compositions having the compositions (parts by mass) shown in Table 1 were prepared.

[0190] (A1) 1,3-Bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3-tetramethyldisiloxane

[0191] (A2) 1,1,1,3,5,5,5-heptamethyl-3-[2-(3,4-epoxycyclohexyl)ethyl]trisiloxane

[0192] (B1) Phenol salt of DBU (U-CAT SA1 manufactured by SAN-APRO CORPORATION)

[0193] (B2) Ethylhexanoate of DBU (U-CAT SA102 manufactured by SAN-APRO CORPORATION)

[0194] (C) 4-Isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate

[0195] (D) 2-Isopropylthioxanthone

[0196] [Table 1]

[0197] Element Example 1 Example 2 Comparative Example 1 Comparative Example 2 (A1) 64.00 64.00 64.00 64.00 (A2) 34.30 34.30 34.30 34.30 (B1) 0.20 - - - (B2) - 0.20 - - (C) 1.50 1.50 1.50 1.50 (D) 0.04 0.04 0.04 0.04 total 100.0 100.0 100.0 100.0 Appearance of curable composition transparent transparent transparent transparent Viscosity of the composition mPa·s 19 19 19 19 Appearance of cured product transparent transparent transparent transparent Outgassing of solidified materials: Condition: 1ppm 210 - 280 - Exhaust of solidified material: Condition: 2ppm - 215 - 290 Storage modulus of cured product MPa 560 560 570 570 Relative dielectric constant of the solidified material 2.6 2.6 2.6 2.6

[0198] As shown in Table 1, the ultraviolet curable composition of the present invention (Examples 1 and 2) has a viscosity at 25°C suitable for application as a coating agent to a substrate, especially a viscosity for application by inkjet printing, and the transparency of the cured product is high. In addition, compared with the cured product obtained from the composition (Comparative Examples 1 and 2) not containing component (B), the amount of outgassing generated by the cured product when kept at a high temperature (110°C or 130°C for 30 minutes in the embodiment) is significantly reduced. On the other hand, the cured product obtained from the ultraviolet curable composition (Examples 1 and 2) has a sufficiently high storage modulus and a sufficiently low relative dielectric constant compared to the cured product obtained from the curable composition not containing component (B), and it can be confirmed that by adding component (B), there is no substantial adverse effect on other cured product properties.

[0199] Industrial Applicability

[0200] The ultraviolet curable composition of the present invention is suitable for the above-mentioned uses, and is particularly suitable as a material for forming an insulating layer of a display device such as a touch panel and a display, especially a flexible display.

Claims

1. A UV-curable composition comprising: (A) one or more organopolysiloxanes or organosilanes having an average number of more than one cationically polymerizable functional group in one molecule; (B) a compound that releases an alkaline substance when heated at 60 to 200° C.; and (C) Photoacid generator, The composition does not substantially contain an organic solvent, and the viscosity of the entire composition measured at 25° C. using an E-type viscometer is 500 mPa·s or less.

2. The ultraviolet curable composition according to claim 1, wherein Component (A) has the average composition formula: R a R' b SiO (4-a-b) / 2 (1) (wherein, R is a cationic polymerizable functional group, R' is a group selected from a monovalent hydrocarbon group, a hydroxyl group and an alkoxy group other than a cationically polymerizable functional group, a and b are numbers satisfying the following conditions: 1≤a+b≤4 and 0.01≤a / (a+b)≤0.5, and the average number of R in the numerator is at least 1) The linear, branched or cyclic organopolysiloxane or organosilane shown.

3. The ultraviolet curable composition according to claim 1, wherein Component (A) contains (A1) one or more organopolysiloxanes having an average of two or more cationically polymerizable functional groups in one molecule, and (A2) one or more organosilanes or organopolysiloxanes having one cationically polymerizable functional group in one molecule.

4. The ultraviolet curable composition according to claim 3, wherein Component (A1) is selected from the following formula (2): [Chemical formula 1] (In the formula, in all R 1 ~R 8 In the group, each molecule has an average of two or more cationic polymerizable functional groups; other R 1 ~R 8 are each independently an unsubstituted or fluorine-substituted monovalent hydrocarbon group; n is a number from 0 to 20), From the average unit formula (3): (R3SiO 1 / 2 ) c (R2SiO 2 / 2 ) d (RSiO 3 / 2 ) e (Not 4 / 2 ) f (3) (wherein, R is independently a group selected from a cationically polymerizable functional group and a monovalent hydrocarbon group that is unsubstituted or substituted with fluorine, at least two of all R are cationically polymerizable functional groups, (e+f) is a positive number, c is 0 or a positive number, and d is a number in the range of 0 to 10) represented by an organopolysiloxane, From the following formula (4): [Chemical formula 2] (wherein, R is independently a group selected from a cationically polymerizable functional group and a monovalent hydrocarbon group that is unsubstituted or substituted with fluorine, x is an integer of 3 to 10, and the molecule has at least two cationically polymerizable functional groups) a cyclic organopolysiloxane represented by and one or more organopolysiloxanes having a cationically polymerizable functional group in the group consisting of a mixture of two or more organopolysiloxanes arbitrarily selected from these.

5. The ultraviolet curable composition according to claim 3, wherein The number of cationically polymerizable functional groups in the component (A1) is two per molecule on average.

6. The ultraviolet curable composition according to claim 3, wherein Component (A1) is a linear organopolysiloxane having cationically polymerizable functional groups only at both ends of the molecular chain and having an average number of silicon atoms in the range of 2 to 12.

7. The ultraviolet curable composition according to claim 3, wherein Component (A2) is selected from the following formula (2'): [Chemical formula 3] (In the formula, in all R 1 ~R 8 In the group, there is only one cationic polymerizable functional group in the molecule; the other R 1 ~R 8 are independently unsubstituted or fluorine-substituted monovalent hydrocarbon groups; n is the viscosity of the (poly)organosiloxane represented by formula (2') at 25°C of 1 to 20 mPa·s, and n can be 0) represented by the organopolysiloxane, Or by the following formula (4'): [Chemical formula 4] (wherein, R is independently a group selected from a cationically polymerizable functional group and a monovalent hydrocarbon group which is unsubstituted or substituted with fluorine, x is an integer of 3 to 10, and the molecule has only one cationically polymerizable functional group) a cyclic organopolysiloxane represented by Or by the following formula (5): RSiR'3(5) An organosilicon compound having one cationic polymerizable functional group in the molecule, which is a member of the group consisting of organosilanes represented by (wherein R is a cationic polymerizable functional group, and R' is a group selected from a monovalent hydrocarbon group, a hydroxyl group and an alkoxy group other than the cationic polymerizable functional group).

8. The ultraviolet curable composition according to claim 3, wherein Component (A2) is an organopolysiloxane having an average of 3 or more silicon atoms and one cationically polymerizable functional group in the molecule.

9. The ultraviolet curable composition according to claim 3, wherein The ultraviolet curable composition contains the component (A1) and the component (A2) in a mass ratio of 10 / 90 to 90 / 10 (A1 / A2).

10. The ultraviolet curable composition according to claim 1, wherein The cationically polymerizable functional group is a group containing an epoxy group.

11. The ultraviolet curable composition according to claim 1, 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.

12. The ultraviolet curable composition according to claim 1, wherein Component (B) is a compound that releases a basic substance when heated at 60 to 120°C.

13. The ultraviolet curable composition according to claim 1, wherein Component (B) is a compound comprising a nitrogen-containing cyclic base. 14 . An insulating coating agent comprising the ultraviolet curable composition according to claim 1 . 15 . A cured product of an ultraviolet curable composition, which is the cured product of the ultraviolet curable composition according to claim 1 .

16. A method of using a cured product of the ultraviolet curable composition according to any one of claims 1 to 13 as an insulating coating. 17 . A display device comprising a layer composed of a cured product of the ultraviolet curable composition according to claim 1 .

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