UV-curable organopolysiloxane composition and application thereof

Abstract

An object of the present invention is to provide a UV-curable organopolysiloxane composition without using an organic solvent, in which a cured product obtained by curing has sufficient hardness and toughness, and has particularly excellent processability when applied to a substrate. The solution is a UV curable organopolysiloxane composition comprising (A1) a branched organopolysiloxane having two or more alkenyl groups in one molecule and a molecular weight of 2,500 or more; (A2) a branched organopolysiloxane having two or more alkenyl groups in one molecule and having a molecular weight of less than 2,500; and (A3) a linear organopolysiloxane having two or more alkenyl groups in one molecule; (B) an organopolysiloxane having two or more silicon-bonded hydrogen atoms in one molecule in an amount in which the molar ratio of the silicon-bonded hydrogen atoms in component (B) to the alkenyl groups in component (A) is in the range of 0.5 to 4.0; and (C) a photoactivatable hydrosilylation catalyst; wherein the mass ratio of the component (A1) to the component (A2) to the component (A3) satisfies the following formula (1): [(A1) + (A2)] / (A3) gt; 1.3 (1) The content X of alkenyl groups per 100 g of the entire composition satisfies the following formula (2): 110 < = X < = 220 (2) The viscosity of the entire composition measured at 25 DEG C using an E-type viscometer ranges from more than 80 mPas to 500 mPas or less, and the composition is substantially free of organic solvents.

Description

Technical Field

[0001] The present invention relates to an ultraviolet (UV)-curable organopolysiloxane composition containing an organosiloxane and / or an organopolysiloxane that can be cured by actinic rays (such as ultraviolet rays or electron beams), and particularly to a UV-curable organopolysiloxane composition, wherein the cured product obtained therefrom has high hardness and good toughness and excellent coating ability. The curable organopolysiloxane composition of the present invention has a low viscosity of less than 500mPas and is suitable as an insulating material for electronic and electrical devices, particularly as a material used as a coating agent. In addition, since it is substantially free of organic solvents, the composition contributes to the simplification of the process. In addition, the cured product obtained by curing the composition performs well in its demoulding properties and can be used as a material (also referred to as a mask, a master mold, a template or a molding material) for a stamp applied to nanoimprint lithography. Background Art

[0002] Due to high heat resistance and excellent chemical stability, silicone resins have been used as coating agents, potting agents, insulating materials, etc. for electronic and electrical devices. Among silicone resins, UV-curable silicone compositions have also been reported.

[0003] As a method for forming fine patterns for semiconductor devices, photolithography is known. In addition, organic silicon materials used therefor are well known. For example, Japanese unexamined patent application 2009-298887 discloses a photopatternable material composed of polysiloxane obtained by hydrolysis and condensation reaction, a photoacid generator and an organic solvent.

[0004] On the other hand, as an alternative to the photolithography process, nanoimprint lithography has been proposed, which is expected to contribute to a significant reduction in the manufacturing cost of semiconductors. The technology includes the following processes: a stamp made of a UV transparent material (such as quartz, etc.) having a fine pattern thereof is contacted with a curable material such as an acrylate-based resin, etc.; the curable material is cured; and the stamp is released from the following cured body. The stamp deteriorates through repeated use and needs to be replaced regularly. However, stamps made of quartz are expensive, and stamps made of resin materials have been studied.

[0005] Japanese unexamined patent application 2015-214637 discloses a nanoimprint master product consisting of a laminate obtained by bonding a thermoplastic resin plate with a cured body from a UV-curable organopolysiloxane resin composition, the UV-curable organopolysiloxane resin composition comprising a linear organopolysiloxane having at least two alkenyl groups, a three-dimensional resinous organopolysiloxane having a specific amount of alkenyl groups, an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule and no alkoxy groups, and a photoactivatable hydrosilylation catalyst. However, due to the high content ratio of the linear organopolysiloxane having at least two alkenyl groups, the composition is formed into an elastomeric cured body with low hardness. In addition, the viscosity of the composition is higher than 2700 mPas and is not suitable for coating process applications such as spin coating applications, etc.

[0006] In addition, Japanese Unexamined Patent Application No. 2010-47646 discloses a UV-curable organopolysiloxane composition comprising a branched organopolysiloxane having at least three alkenyl groups, a linear organopolysiloxane having at least two alkenyl groups, and a polysiloxane composed of SiO 4 / 2 Unit and R 3 SiO 1 / 2 The present invention relates to an organohydrogenpolysiloxane having a branched organopolysiloxane unit composition and having at least three silicon-bonded hydrogen atoms in one molecule, and a (methylcyclopentadienyl)trialkylplatinum complex. Although the cured body from the composition has a sufficiently high hardness due to its high content ratio of branched organopolysiloxane, the composition is not suitable for coating process applications such as spin coating applications due to its high viscosity of 5,100 mPas.

[0007] On the other hand, Japanese unexamined patent application 2005-227701 discloses a curable organopolysiloxane composition that is applied to light transmission articles, which is included in an organopolysiloxane with at least two silicon-bonded alkenyl groups in one molecule, an organopolysiloxane or an organosilicon compound with at least two silicon-bonded hydrogen atoms in one molecule, and a hydrosilylation catalyst. The viscosity of said composition is as low as 800mPas or lower, and its solidified body has good flexibility. However, the relationship between the mechanical strength in the solidified body obtained thereby and the molecular weight of the branched organopolysiloxane is not studied. In addition, the hardness of the solidified body obtained by said composition is not high enough. In addition, this patent documentation does not mention UV curability at all.

[0008] Related technical literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Unexamined Patent Application 2015-214637

[0011] Patent Document 2: Japanese Unexamined Patent Application 2010-047646

[0012] Patent Document 3: Japanese Unexamined Patent Application 2005-227701 Summary of the invention

[0013] Problems Solved by the Invention

[0014] As described above, curable organopolysiloxane compositions and low-viscosity organopolysiloxane compositions applied to nanoimprint molded products are well known, but there is still a need for UV-curable organopolysiloxane compositions, wherein the cured product obtained therefrom has sufficient hardness and toughness and has excellent processability to be applied to a substrate, especially low viscosity. That is, an object of the present invention is to provide a UV-curable organopolysiloxane composition, wherein the cured product obtained by curing has sufficient hardness and toughness and has particularly excellent processability when applied to a substrate.

[0015] Methods used to solve problems

[0016] The present invention has been accomplished by the following findings: a UV-curable organopolysiloxane composition having a viscosity ranging from more than 80 mPas to 500 mPas or less as measured at 25° C. for the entire composition using an E-type viscometer is comprehensively designed by using (A) a mixture of at least two kinds of branched organopolysiloxanes having at least two alkenyl groups in one molecule and different in molecular weight and a linear organopolysiloxane having at least two alkenyl groups in one molecule, (B) an organopolysiloxane having two or more silicon-bonded hydrogen atoms in one molecule, and a photoactivatable hydrosilylation catalyst, without containing an organic solvent in the composition; and by controlling the content of alkenyl groups in the composition, the curable composition is excellent in its processability such as its coatability and the cured body obtained therefrom is sufficiently high in its hardness and toughness.

[0017] The ultraviolet (UV)-curable organopolysiloxane composition of the present invention is characterized by comprising (A1) a branched organopolysiloxane having two or more alkenyl groups in one molecule and having a molecular weight of 2,500 or more;

[0018] (A2) a branched organopolysiloxane having two or more alkenyl groups in one molecule and a molecular weight of less than 2,500; and

[0019] (A3) a linear organopolysiloxane having two or more alkenyl groups in one molecule;

[0020] (B) an organopolysiloxane having two or more silicon-bonded hydrogen atoms in one molecule, in an amount ranging from 0.5 to 4.0 in a molar ratio of the silicon-bonded hydrogen atoms in the component (B) relative to the alkenyl groups in the component (A); and

[0021] (C) a photoactivatable hydrosilylation catalyst;

[0022] The mass ratio of component (A1), component (A2) and component (A3) satisfies the following formula (1):

[0023] [(A1)+(A2)] / (A3)>1.3 (1)

[0024] The content X of alkenyl groups per 100 g of the entire composition satisfies the following formula (2): 110≤X≤220(2)

[0025] The viscosity of the entire composition measured at 25° C. using an E-type viscometer ranges from more than 80 mPas to 500 mPas or less, and

[0026] The composition is substantially free of organic solvents.

[0027] It is preferred that the mass parts of component (A1), component (A2) and component (A3) satisfy the following conditions: (A1): 25 to 75 parts by mass; (A2): 3 to 60 parts by mass; and (A3): 5 to 40 parts by mass; wherein the total mass of components (A) to (C) in the composition is 100 parts by mass.

[0028] Component (A3) is preferably a linear organopolysiloxane having an alkenyl group at a molecular terminal thereof.

[0029] Component (B) is preferably a linear organopolysiloxane having two or more silicon-bonded hydrogen atoms in one molecule.

[0030] Component (A1) is preferably a branched organopolysiloxane having an alkenyl group, and is represented by the following average unit formula:

[0031] (R 1 3SiO 1 / 2 ) a1 (R 1 2SiO 2 / 2 ) b1 (R 1 SiO 3 / 2 ) c1 (SiO 4 / 2 ) d1 (3)

[0032] (where R 1are independently monovalent hydrocarbon groups having 1 to 12 carbon atoms,

[0033] All R 1 At least two of the above are alkenyl groups having 2 to 12 carbon atoms, and a1, b1, c1 and d1 are values ​​satisfying the following conditions: a1+b1+c1+d1=1, 0≤a1≤0.5, 0≤b1≤0.4, 0≤c1≤0.8, and 0≤d1≤0.7, 0.5≤c1+d1≤0.8)

[0034] Component (A2) is preferably a branched organopolysiloxane having an alkenyl group, and is represented by the following average unit formula:

[0035] (R 2 3SiO 1 / 2 ) a2 (R 2 2SiO 2 / 2 ) b2 (R 2 SiO 3 / 2 ) c2 (SiO 4 / 2 ) d2 (4)

[0036] (where R 2 are independently monovalent hydrocarbon groups having 1 to 12 carbon atoms,

[0037] All R 2 At least two of them are alkenyl groups having 2 to 12 carbon atoms, and a2, b2, c2 and d2 are values ​​satisfying the following conditions: a2+b2+c2+d2=1, 0≤a2≤0.5, 0≤b2≤0.8, 0≤c2<0.5, and 0≤d2<0.5, 0≤ <c2+d2<0.5)。

[0038] It is preferred that the mass ratio of component (A1), component (A2) and component (A3) satisfies the following formula: [(A1)+(A2)] / (A3)≥1.5 (5).

[0039] The hardness of the cured body obtained by curing the composition measured at 25° C. using a type D durometer is preferably 30 or more.

[0040] The viscosity measured at 25° C. using an E-type viscometer for the entire composition is preferably in the range of 100 mPas to 350 mPas.

[0041] Component (C) is preferably an unsubstituted or alkyl-substituted (cyclopentadienyl)trialkylplatinum complex.

[0042] The UV-curable organopolysiloxane composition of the present invention is suitable for use as an insulating coating agent. Therefore, the present invention provides an insulating coating agent comprising the UV-curable organopolysiloxane composition.

[0043] Furthermore, the present invention provides a cured body obtained by curing the UV-curable organopolysiloxane composition.

[0044] Furthermore, the present invention provides use of the UV-curable organopolysiloxane composition as a stamp-forming material for nanoimprint lithography.

[0045] Effects of the Invention

[0046] The UV-curable organopolysiloxane composition of the present invention has low viscosity without using an organic solvent and is excellent in its coating ability on a substrate via a spin coating process or the like, and this composition has good curability and the hardness of the cured product obtained by curing is sufficiently high and has good toughness. DETAILED DESCRIPTION

[0047] First, the UV-curable organopolysiloxane composition of the present invention (hereinafter may be referred to as "curable composition" or "UV-curable composition") will be described in further detail below. In addition, in the present invention, the molecular weight means a weight average molecular weight of a relative value of a polystyrene standard measured by a gel permeation chromatography (GPC) method.

[0048] The curable composition of the present invention is characterized by comprising:

[0049] (A1) a branched organopolysiloxane having two or more alkenyl groups in one molecule and having a molecular weight of 2,500 or more;

[0050] (A2) a branched organopolysiloxane having two or more alkenyl groups in one molecule and a molecular weight of less than 2,500; and

[0051] (A3) a linear organopolysiloxane having two or more alkenyl groups in one molecule;

[0052] (B) an organopolysiloxane having two or more silicon-bonded hydrogen atoms in one molecule in an amount within the range of 0.5 to 4.0 in a molar ratio of silicon-bonded hydrogen atoms in component (B) relative to alkenyl groups in component (A); and

[0053] (C) a photoactivatable hydrosilylation catalyst;

[0054] The mass ratio of component (A1), component (A2) and component (A3) satisfies the following formula (1):

[0055] [(A1)+(A2)] / (A3)>1.3 (1)

[0056] The content X of alkenyl groups per 100 g of the entire composition satisfies the following formula (2): 110≤X≤220(2)

[0057] The viscosity of the entire composition measured at 25° C. using an E-type viscometer ranges from more than 80 mPas to 500 mPas or less, and

[0058] The composition is substantially free of organic solvents.

[0059] Since the UV-curable composition contains a component (C) of a photoactivatable hydrosilylation catalyst, the catalyst is activated as a hydrosilylation reaction catalyst by exposure to actinic light (e.g., UV rays), resulting in curing by crosslinking caused by an addition reaction between the alkenyl groups of the component (A) and the silicon-bonded hydrogen atoms (Si—H) (i.e., hydrosilyl groups) in the component (B).

[0060] Component (A), component (B), component (C) and other optional components will be described in further detail below.

[0061] [Component (A)]

[0062] Component (A) is a mixture of the main component of the composition and an organopolysiloxane having an alkenyl group. Specifically, component (A) consists of the following component (A1), component (A2) and component (A3), and the mass ratio of each component satisfies a specific relationship.

[0063] [Component (A1): Branched organopolysiloxane having two or more alkenyl groups in one molecule and having a molecular weight of 2,500 or more]

[0064] Component (A1) is an organopolysiloxane with an alkenyl group (i.e., a curable group comprising a carbon-carbon double bond). The carbon-carbon double bond can be a carbon-carbon double bond that reacts with a Si-H group by hydrosilylation, and is not limited to the alkenyl group with a specific chemical structure. The alkenyl group is preferably an alkenyl group on a molecular end, and is exemplified by, but not limited to, an alkenyl group with C2 to C20, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl and 4-vinylphenyl groups. The alkenyl group is particularly preferably selected from the one in vinyl, allyl and hexenyl groups, and vinyl groups are most preferred.

[0065] The branched organopolysiloxane of component (A1) is a branched (more specifically, having a branched structure or a resinous (network) structure) organopolysiloxane having two or more alkenyl groups in one molecule and having a molecular weight of 2,500 or more, preferably 3000 or more. By formulating the branched organopolysiloxane having a higher molecular weight, the hardness and toughness of the cured body obtained by curing the composition are improved. The component (A1) preferably contains 25 or more, more preferably 30 or more silicon atoms. As component (A1), one type of branched organopolysiloxane or a combination of at least two types of branched organopolysiloxanes can be used.

[0066] In addition to the alkenyl group, the branched organopolysiloxane of component (A1) may include any functional group selected from the group consisting of monovalent hydrocarbon groups, hydroxyl groups and alkoxy groups that do not include carbon-carbon double bonds in the molecule. The monovalent hydrocarbon group includes unsubstituted monovalent hydrocarbon groups and fluorine-substituted monovalent hydrocarbon groups. Unsubstituted or fluorine-substituted monovalent hydrocarbon groups are preferably selected from the following groups: unsubstituted or fluorine-substituted alkyl, cycloalkyl, arylalkyl and aryl groups with 1 to 20 carbon atoms. Examples of the above-mentioned alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, amyl, octyl and other groups, and methyl groups are particularly preferred. Examples of the above-mentioned cycloalkyl groups include cyclopentyl, cyclohexyl, etc. Examples of the above-mentioned arylalkyl groups include benzyl, phenylethyl groups, etc. Examples of the above-mentioned aryl groups include phenyl groups, naphthyl groups, etc. Examples of the fluorine-substituted monovalent hydrocarbon group include a 3,3,3-trifluoropropyl group and a 3,3,4,4,5,5,5,6,6,6-nonafluorohexyl group. A 3,3,3-trifluoropropyl group is preferred as the fluorine-substituted monovalent hydrocarbon group.

[0067] In the branched organopolysiloxane of component (A1), its Si atom-bonded organic groups other than alkenyl groups are preferably substantially methyl groups. That is, among all Si atom-bonded organic groups other than alkenyl groups, preferably 95 mol % or more, more preferably 99 mol % or more, and most preferably 100 mol % of the organic groups are methyl groups. Therefore, the most preferred embodiment of component (A1) is an organosiloxane having a vinyl group as an alkenyl group, and wherein the Si atom-bonded organic groups other than alkenyl groups are substantially methyl groups, and are preferably one species or a combination of at least two species selected from the group of branched organopolysiloxanes and resinous organopolysiloxanes.

[0068] The branched organopolysiloxane of component (A1) is generally in a solid state, although this state may vary depending on its molecular weight, its molecular weight distribution, and the kind of substituent groups on Si atoms. When preparing the UV-curable organopolysiloxane composition of the present invention, component (A1) may be directly formulated as one of the raw materials. On the other hand, it is preferred that component (A1) may be formulated as a liquid mixture by premixing component (A1) with other organopolysiloxanes, particularly a linear organopolysiloxane (A3) having an alkenyl group, to simplify the manufacturing process.

[0069] Preferably, component (A1) is a branched organopolysiloxane represented by the following average unit formula or a mixture of two or more types:

[0070] (R 1 3SiO 1 / 2 ) a1 (R 1 2SiO 2 / 2 ) b1 (R 1 SiO 3 / 2 ) c1 (SiO 4 / 2 ) d1 (3)

[0071] In this formula, R 1 are independently monovalent hydrocarbon groups having 1 to 12 carbon atoms, all R 1 At least two of them are alkenyl groups having 2 to 12 carbon atoms, and a1, b1, c1 and d1 are values ​​satisfying the following conditions: a1+b1+c1+d1=1, 0≤a1≤0.5, 0≤b1≤0.4, 0≤c1≤0.8, and 0≤d1≤0.7, 0.5≤c1+d1≤0.8. R representing an alkenyl group and another monovalent hydrocarbon group having 1 to 12 carbon atoms is 1 , the above groups can be used. Regarding the preferred ratio of each siloxane unit, when a1, b1, c1 and d1 are within the range, a higher molecular weight of the branched organopolysiloxane can be easily designed. In addition, when c1+d1 is higher than the lower limit, it is preferred for the branched organopolysiloxane to easily have a higher molecular weight. On the other hand, when c1+d1 is lower than the above upper limit, it is preferred for being able to produce a branched organopolysiloxane more stably.

[0072] The organopolysiloxane represented by the following average unit formula is exemplified as the branched organopolysiloxane having an alkenyl group that can be used as the component (A1). In the following formula, Me, Vi, Ph each represent a methyl group, a vinyl group, and a phenyl group; n, m, l, and k each represent a molar ratio of each siloxane unit, and each are greater than 0 and less than 1, provided, however, that these values ​​satisfy the condition n+m+l+k=1.

[0073] (Me3SiO 1 / 2 ) n (Me2ViSiO 1 / 2 ) m (SiO 4 / 2 ) l [0.5≤l]

[0074] (Me2ViSiO 1 / 2 ) n (SiO 4 / 2 ) m [0.5≤m]

[0075] (Me3SiO 1 / 2 ) n (Me2ViSiO 1 / 2 ) m (Me2SiO 2 / 2 ) l (SiO 4 / 2 ) k [0.5≤k]

[0076] (Me2ViSiO 1 / 2 ) n (Me2SiO 2 / 2 ) m (SiO 4 / 2 ) l [0.5≤l]

[0077] (Me3SiO 1 / 2 ) n (MeViSiO 2 / 2 ) m (SiO 4 / 2 ) l [0.5≤l]

[0078] (Me2ViSiO 1 / 2 ) n (MeSiO 3 / 2 ) m [0.5≤m]

[0079] (Me3SiO 1 / 2 ) n (Me2ViSiO 1 / 2 )m (MeSiO 3 / 2 ) l [0.5≤l]

[0080] (Me3SiO 1 / 2 ) n (Me2ViSiO 1 / 2 ) m (Me2SiO 2 / 2 ) l (MeSiO 3 / 2 ) k [0.5≤k]

[0081] (Me2ViSiO 1 / 2 ) n (Me2SiO 2 / 2 ) m (MeSiO 3 / 2 ) l [0.5≤l]

[0082] (Me2ViSiO 1 / 2 ) n (PhSiO 3 / 2 ) m [0.5≤m]

[0083] (Me2ViSiO 1 / 2 ) n (Me2SiO 2 / 2 ) m (PhSiO 3 / 2 ) l [0.5≤l]

[0084] (Me2ViSiO 1 / 2 ) n (MePhSiO 2 / 2 ) m (PhSiO 3 / 2 ) l [0.5≤l]

[0085] (Me2ViSiO 1 / 2 ) n (Ph2SiO 2 / 2 ) m (PhSiO 3 / 2 ) l [0.5≤l]

[0086] The organopolysiloxane of component (A1) may contain a small amount of silanol groups or alkoxysilyl groups which do not affect the hydrosilylation reaction thereof. Here, a small amount means less than 5 mol% of all substituent groups bonded to Si atoms.

[0087] [Component (A2): a branched organopolysiloxane having two or more alkenyl groups in one molecule and a molecular weight of less than 2,500]

[0088] Similar to component (A1), the organopolysiloxane of component (A2) is an organopolysiloxane having an alkenyl group (i.e., a curable group containing a carbon-carbon double bond). The carbon-carbon double bond can be a carbon-carbon double bond that reacts with a Si-H group through a hydrosilylation reaction, and is not limited to an alkenyl group with a specific chemical structure. The alkenyl group is particularly preferably selected from one of a vinyl, an allyl and a hexenyl group, and a vinyl group is most preferred.

[0089] The branched organopolysiloxane of component (A2) is a branched (more specifically, having a branched structure or a resinous (network) structure) organopolysiloxane having two or more alkenyl groups in one molecule, having a molecular weight of less than 2,500, preferably less than 2000, and is generally liquid. By formulating this liquid, branched organopolysiloxane with a relatively low molecular weight, the viscosity of the entire composition is reduced and its coating ability is improved. In addition, the use of component (A2) in combination contributes to a higher hardness of the cured body obtained by curing the composition. The component (A2) preferably contains less than 25, more preferably less than 20 silicon atoms. As component (A2), one type of branched organopolysiloxane or a combination of at least two types of branched organopolysiloxanes can be used.

[0090] In addition to the alkenyl group, the branched organopolysiloxane of component (A2) may contain any functional group selected from the group consisting of a monovalent hydrocarbon group not containing a carbon-carbon double bond, a hydroxyl group, and an alkoxy group in the molecule. Herein, regarding these functional groups, the same groups as exemplified in component (A1) may be used.

[0091] In the branched organopolysiloxane of component (A2), its organic groups bonded to Si atoms other than alkenyl groups are preferably substantially methyl groups. That is, among all the organic groups bonded to Si atoms other than alkenyl groups, preferably 95 mol % or more, more preferably 99 mol % or more, and most preferably 100 mol % of the organic groups are methyl groups. Therefore, the most preferred embodiment of component (A2) is an organosiloxane having a vinyl group as an alkenyl group, and wherein its organic groups bonded to Si atoms other than alkenyl groups are substantially methyl groups, and preferably one type or a combination of at least two types selected from the group of branched organopolysiloxane and resinous organopolysiloxane.

[0092] Preferably, component (A2) is a branched organopolysiloxane represented by the following average unit formula or a mixture of two or more types:

[0093] (R 2 3SiO 1 / 2 ) a2 (R 2 2SiO 2 / 2 ) b2 (R 2 SiO 3 / 2 ) c2 (SiO 4 / 2 ) d2 (4)

[0094] In this formula, R 2 is independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, and at least two of all R 2 are alkenyl groups having 2 to 12 carbon atoms. a2, b2, c2, and d2 are numerical values satisfying the following conditions: a2 + b2 + c2 + d2 = 1, 0 ≤ a2 ≤ 0.5, 0 ≤ b2 ≤ 0.8, 0 ≤ c2 < 0.5, and 0 ≤ d2 < 0.5, 0 < c2 + d2 < 0.5. As R 2 representing the alkenyl group and other monovalent hydrocarbon groups having 1 to 12 carbon atoms, the above-mentioned groups of group R 1 can be used. Regarding the preferred ratio of each siloxane unit, when a2, b2, c2, and d2 are within the above ranges, the lower molecular weight of the branched organopolysiloxane can be easily designed. In addition, when c2 + d2 is within the above range, it is preferable to form a branched organopolysiloxane, and its molecular weight tends not to be too high.

[0095] The organopolysiloxane represented by the following average unit formula is an example of a branched organopolysiloxane having an alkenyl group that can be used as the component (A2). In the following formula, Me, Vi, and Ph each represent a methyl, vinyl, and phenyl group; n, m, l, and k respectively represent the molar ratio of each siloxane unit, and each is greater than 0 and less than 1. However, the condition is that these numerical values satisfy the condition n + m + l + k = 1.

[0096] (Me3SiO 1 / 2 ) n (Me2ViSiO 1 / 2 ) m (SiO 4 / 2 ) l [l < 0.5]

[0097] (Me2ViSiO 1 / 2 ) n (SiO 4 / 2 ) m [m < 0.5; preferably, an organopolysiloxane satisfying 3.0 ≤ n / m ≤ 4.0]

[0098] (Me3SiO 1 / 2 ) n (Me2ViSiO 1 / 2 ) m (Me2SiO 2 / 2 ) l (SiO 4 / 2 ) k [k<0.5]

[0099] (Me2ViSiO 1 / 2 ) n (Me2SiO 2 / 2 ) m (SiO 4 / 2 ) l [l<0.5]

[0100] (Me3SiO 1 / 2 ) n (MeViSiO 2 / 2 ) m (SiO 4 / 2 ) l [l<0.5]

[0101] (Me2ViSiO 1 / 2 ) n (MeSiO 3 / 2 ) m [m<0.5; preferably, an organopolysiloxane satisfying 1.5≤n / m≤3.0]

[0102] (Me3SiO 1 / 2 ) n (Me2ViSiO 1 / 2 ) m (MeSiO 3 / 2 ) l [l<0.5]

[0103] (Me3SiO 1 / 2 ) n (Me2ViSiO 1 / 2 ) m (Me2SiO 2 / 2 ) l (MeSiO 3 / 2 ) k [k<0.5]

[0104] (Me2ViSiO 1 / 2 ) n (Me2SiO 2 / 2 ) m (MeSiO 3 / 2 ) l [l<0.5]

[0105] (Me2ViSiO 1 / 2 ) n (PhSiO 3 / 2 ) m [m<0.5; preferably, an organopolysiloxane satisfying 1.5≤n / m≤3.0]

[0106] (Me2ViSiO 1 / 2 ) n (Me2SiO 2 / 2 ) m (PhSiO 3 / 2 ) l [l<0.5]

[0107] (Me2ViSiO 1 / 2 ) n (MePhSiO 2 / 2 ) m (PhSiO 3 / 2 ) l [l<0.5]

[0108] (Me2ViSiO 1 / 2 ) n (Ph2SiO 2 / 2 ) m (PhSiO 3 / 2 ) l [l<0.5]

[0109] The organopolysiloxane of component (A2) may contain a small amount of silanol groups or alkoxysilyl groups which do not affect its hydrosilylation reaction. Here, a small amount means less than 5 mol% of all substituent groups bonded to Si atoms.

[0110] [Component (A3): linear organopolysiloxane having two or more alkenyl groups in one molecule]

[0111] Similar to components (A1) and (A2), component (A3) is a straight chain organopolysiloxane having an alkenyl group (i.e., a curable group containing a carbon-carbon double bond). The carbon-carbon double bond can be a carbon-carbon double bond that reacts with a Si-H group through a hydrosilylation reaction, and is not limited to an alkenyl group having a specific chemical structure. The alkenyl group is particularly preferably one selected from a vinyl, allyl, and hexenyl group, and a vinyl group is most preferred.

[0112] Component (A3) is a straight chain organopolysiloxane having two or more alkenyl groups on average in a molecule. From the viewpoint of providing flexibility and toughness for the cured body from the curable composition, component (A3) is preferably a straight chain organopolysiloxane having alkenyl groups at both ends. The degree of polymerization (i.e., the number of silicon atoms) of component (A3) is not limited, but component (A3) may include an average of 5 or more, more preferably 10 or more organosilicon atoms per molecule, and in addition, an average of 1000 or less, more preferably 500 or less organosilicon atoms per molecule. In particular, from the viewpoint of controlling the viscosity of the curable composition, component (A3) preferably includes 30 to 200 silicon atoms. By preparing this component (A3), the viscosity of the entire composition is reduced, and its flexibility and toughness are improved in the cured body obtained by curing the composition. As this straight chain organopolysiloxane with alkenyl groups, a combination of one type or at least two types can be used.

[0113] In addition to the alkenyl group, the linear organopolysiloxane of component (A3) may contain any functional group selected from the group consisting of a monovalent hydrocarbon group not containing a carbon-carbon double bond, a hydroxyl group, and an alkoxy group in the molecule. Herein, regarding these functional groups, the same groups as exemplified in components (A1) and (A2) can be used.

[0114] In the linear organopolysiloxane of component (A3), similar to component (A1) or component (A2), its Si atom-bonded organic groups other than alkenyl groups are preferably substantially methyl groups. That is, among all silicon atom-bonded organic groups other than alkenyl groups, preferably 95 mol% or more, more preferably 99 mol% or more, and most preferably 100 mol% of the organic groups are methyl groups. Therefore, the most preferred embodiment of component (A3) is a linear organosiloxane having a vinyl group as an alkenyl group, and wherein its silicon atom-bonded organic groups other than alkenyl groups are substantially methyl groups, and preferably one type or a combination of at least two types of the linear organopolysiloxane has a vinyl group at both ends.

[0115] As an example of the straight-chain organopolysiloxane having an alkenyl group that can be used as the component (A3), an organopolysiloxane represented by the following average unit formula is used. In the following formula, Me, Vi, Ph each represent a methyl group, a vinyl group, and a phenyl group; n, m, and l each represent a molar ratio of each siloxane unit, and each are greater than 0 and less than 1, provided, however, that these values ​​satisfy the condition n+m+l=1.

[0116] (Me2ViSiO 1 / 2 ) n (Me2SiO 2 / 2) m

[0117] (Me2ViSiO 1 / 2 ) n (Me2SiO 2 / 2 ) m (MeViSiO 2 / 2 ) l

[0118] (Me3SiO 1 / 2 ) n (Me2SiO 2 / 2 ) m (MeViSiO 2 / 2 ) l

[0119] (Me3SiO 1 / 2 ) n (MeViSiO 2 / 2 ) m

[0120] (Me2ViSiO 1 / 2 ) n (MePhSiO 2 / 2 ) m

[0121] (Me2ViSiO 1 / 2 ) n (Me2SiO 2 / 2 ) m (Ph2SiO 2 / 2 ) l

[0122] (Me2ViSiO 1 / 2 ) n (Ph2SiO 2 / 2 ) m

[0123] (Me3SiO 1 / 2 ) n (MePhSiO 2 / 2 ) m (MeViSiO 2 / 2 ) l

[0124] (Me3SiO 1 / 2 ) n (Ph2SiO 2 / 2 ) m (MeViSiO 2 / 2 ) l

[0125] When the total mass of components (A) to (C) in the composition is 100 parts by mass, the mass parts of components (A1), (A2) and (A3) preferably satisfy the following conditions: (A1): 25 parts by mass to 75 parts by mass; (A2): 3 parts by mass to 60 parts by mass; and (A3): 5 parts by mass to 40 parts by mass. These mass ratios of the components (A1), (A2) and (A3) can be determined in consideration of the viscosity of the composition, the hardness and toughness in the cured body obtained by curing the composition.

[0126] In the curable composition of the present invention, the mass ratio of component (A1), component (A2) and component (A3) is required to satisfy the following formula (1):

[0127] [(A1)+(A2)] / (A3) > 1.3 (1)

[0128] This formula (1) means that the mass ratio of the branched organopolysiloxane (A1, A2) to the linear organopolysiloxane exceeds 1.3. From the viewpoint of hardness, particularly the suitable hardness of the cured body as a stamp material for nanoimprint lithography, the preferred value of the mass ratio is equal to or exceeds 1.5. More preferred is a value range of 1.5 to 10.0. On the other hand, when the value is 1.3 or less, due to its higher ratio of the linear organopolysiloxane in the composition, the hardness of the cured body is low and the purpose of the present invention cannot be achieved.

[0129] Furthermore, the content of alkenyl groups (X, unit: mmol) per 100 g of the entire organopolysiloxane composition is required to satisfy the following formula (2):

[0130] 110 ≤ X ≤ 220 (2)

[0131] When the value is lower than 110, it is difficult to design a composition having a preferred viscosity for application in a coating process, or the cured body tends to have a lower hardness after curing. On the other hand, when the value exceeds 220, the toughness of the cured body after curing becomes worse, and the purpose of the present invention cannot be achieved. The range of the X value is preferably 130≤X≤200, and more preferably 130≤X≤180.

[0132] [Component (B): an organopolysiloxane having two or more silicon-bonded hydrogen atoms in one molecule]

[0133] The organopolysiloxane having silicon-bonded hydrogen atoms (hereinafter, may be referred to as "organohydrogenpolysiloxane") of component (B) has an average of two or more silicon-bonded hydrogen atoms in one molecule, and may be used as a crosslinking agent to form a crosslinked structure through its hydrosilylation reaction with component (A) having an alkenyl group.

[0134] One type or two or more types selected from the group consisting of organohydrogenpolysiloxanes having a linear form, a branched form, a cyclic form and a resinous form may be used as component (B). Such organohydrogenpolysiloxane is a well-known compound in the technical field of the present invention.

[0135] As component (B), examples of the linear organohydrogenpolysiloxane are, but are not limited to, 1,1,3,3-tetramethyldisiloxane, methylhydrogenpolysiloxane terminated with trimethylsiloxy groups at both ends of the molecular chain, dimethylsiloxane / methylhydrogensiloxane copolymer terminated with trimethylsiloxy groups at both ends of the molecular chain, dimethylpolysiloxane terminated with dimethylhydrogensiloxy groups at both ends of the molecular chain, dimethylsiloxane / methylhydrogensiloxane copolymer terminated with dimethylhydrogensiloxy groups at both ends of the molecular chain, methylhydrogensiloxane / diphenylsiloxane copolymer terminated with trimethylsiloxy groups at both ends of the molecular chain, and methylhydrogensiloxane / diphenylsiloxane / dimethylsiloxane copolymer terminated with trimethylsiloxy groups at both ends of the molecular chain. One type or a combination of at least two types of these linear organohydrogenpolysiloxanes may be used. As component (B) of the present invention, of all silicon-bonded organic groups excluding silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane, preferably 80 mol% or more, more preferably 90 mol% to 100 mol% of the organic groups are methyl groups.

[0136] As component (B), examples of branched, cyclic and resinous organohydrogenpolysiloxanes are 1,3,5,7-tetramethylcyclotetrasiloxane, tris(dimethylhydrogensiloxy)methylsilane, tris(dimethylhydrogensiloxy)phenylsilane, tetrakis(dimethylhydrogensiloxy)silane, hydrolysis condensation products of trimethoxysilane, and mixtures of two or more types selected therefrom. Further examples of the resinous organohydrogenpolysiloxane include at least one type of organohydrogenpolysiloxane resin selected from the following: H MQ type, M H Q type, M H MT type, M H T type, M H MQT type, M H QT type, M H MDQ type, M H MDD H Q type, M H DQ type, M H DD H Q type, M H MDT type, M H MDD H T type, M H DT type, M HDD H T type, M H MDQT type, M H MDD H QT type, M H DQT type and M H DD H QT type, wherein the organohydrogenpolysiloxane contains at least one branched siloxane unit selected from the group consisting of: SiO 4 / 2 Unit (Q unit) and R 3 SiO 3 / 2 Unit (T unit), R 3 3SiO 1 / 2 Unit (M unit), R 3 3HSiO 1 / 2 Unit (M H unit), and optionally contains R 3 2SiO 2 / 2 Unit (D unit), R 3 HSiO 2 / 2 Unit (D H Unit). One type thereof, or a combination of two or more types thereof may be used. 3 It may be independently a methyl or phenyl group, and is preferably a methyl group.

[0137] The branched, cyclic or resinous organohydrogenpolysiloxane of component (B) may contain a small amount of silanol groups or alkoxysilyl groups which do not affect the hydrosilylation reaction thereof. Here, a small amount means less than 5 mol% of all substituent groups bonded to Si atoms.

[0138] As component (B), one type or a combination of two or more types of the linear, branched, cyclic and resinous organohydrogenpolysiloxanes may be used. Preferred is a linear organohydrogenpolysiloxane.

[0139] As the (B) component of the present invention, the hydrogen content of hydrogen radicals bonded to silicon atoms of the organohydrogenpolysiloxane is preferably within 0.1 to 1.6 mass %, more preferably within 0.2 to 1.5 mass %, and most preferably within 0.4 to 1.5 mass %.

[0140] The viscosity of component (B) at 25° C. is preferably 2 to 100 mPas, but when it is combined with component (A) and component (C), an organohydrogenpolysiloxane having an optional viscosity may be used so that the viscosity measured at 25° C. for the entire composition using an E-type viscometer ranges from greater than 80 mPas to 500 mPas or less.

[0141] In the curable composition of the present invention, the content of component (A) is such an amount that the amount of silicon-bonded hydrogen atoms in component (B) ranges from 0.5 mol to 4.0 mol, preferably from 0.7 mol to 3.0 mol, and most preferably from 0.7 mol to 2.0 mol per 1 mol of alkenyl groups in component (A). When the amount of silicon-bonded hydrogen atoms in component (B) is within the range, a curable composition having good curability and excellent physical properties in a cured body after curing can be obtained.

[0142] [Component (C): Photoactivatable Hydrosilylation Catalyst]

[0143] Component (C) is a photoactivatable hydrosilylation catalyst which provides curing properties to the curable composition of the present invention by irradiation with actinic rays (e.g., UV rays). To activate component (C), UV (ultraviolet) radiation with a wavelength of 280 nm to 380 nm is readily used in industry. The exposure amount depends on the type of catalyst activated by high-energy radiation. In the case of ultraviolet radiation, the total exposure at a wavelength of 365 nm is preferably between 100 mJ / cm 2 Up to 10J / cm 2 within the range.

[0144] Although component (C) is not limited to a specific compound to the extent that the compound exerts catalytic activity as a hydrosilylation catalyst by UV ray irradiation, it is preferred to use a photoactivatable platinum complex. Examples of the photoactivatable platinum complex include (methylcyclopentadienyl)trimethylplatinum (IV), (cyclopentadienyl)trimethylplatinum (IV), (1,2,3,4,5-pentamethylcyclopentadienyl)trimethylplatinum (IV), (cyclopentadienyl)dimethylethylplatinum (IV), (cyclopentadienyl)dimethylacetylplatinum (IV), (trimethylsilylcyclopentadienyl)trimethylplatinum (IV), (methoxycarbonylcyclopentadienyl)trimethylplatinum (IV), (dimethylphenylsilylcyclopentadienyl)trimethylcyclopentadienylplatinum (IV), bis(1-phenyl-1,3-butanedione)platinum(II), bis(1,3-diphenyl-1,3-propanedione)platinum(II), and bis(hexafluoroacetylacetonate)platinum(II).

[0145] As component (C), a (cyclopentadienyl)trialkylplatinum complex or a derivative thereof in which the cyclopentadienyl ligand is substituted with an alkyl group is preferred, and from the standpoint of versatility and availability, (methylcyclopentadienyl)trimethylplatinum (IV) is preferred. Furthermore, as component (C), from the standpoint of versatility and availability, bis(2,4-pentanedione)platinum (II) is preferred.

[0146] The amount of component (C) is an amount required to cure the curable composition of the present invention at an industrially sufficient curing speed. The amount of platinum metal atoms in component (C) is in the range of 1 ppm to 500 ppm, and preferably in the range of 5 ppm to 100 ppm, and more preferably in the range of 10 ppm to 100 ppm, relative to the mass of the UV-curable organopolysiloxane composition.

[0147] The curable composition of the present invention may optionally include a hydrosilylation reaction inhibitor. Typically, the hydrosilylation reaction inhibitor is added to the composition to improve the shelf life of the composition and to obtain a stable curable composition. However, in order to avoid slowing down its curing speed, the curable composition of the present invention does not necessarily include a hydrosilylation reaction inhibitor. On the other hand, in order to extend the usable time of the curable composition, a hydrosilylation reaction inhibitor may be added to the composition. In the present technical field, hydrosilylation reaction inhibitors are well known, and examples thereof include acetylenic alcohols such as 1-ethynylcyclohexan-1-ol, 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, and 2-phenyl-3-butyn-2-ol; enyne compounds such as 3-methyl-3-pentene-1-yne and 3,5-dimethyl-3-hexene-1-yne; methylalkenylsiloxane oligomers such as 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane and 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane; alkynyloxysilanes such as dimethylbis(1,1-dimethyl-2-propynyloxy)silane and methylvinylbis(1,1-dimethyl-2-propynyloxy)silane; and triaryl isocyanurate-based compounds.

[0148] When the hydrosilylation reaction inhibitor is used in the UV-curable organopolysiloxane composition of the present invention, the amount of the hydrosilylation reaction inhibitor is not particular, but the hydrosilylation reaction inhibitor is preferably used in the range of 0.0001 part by mass to 1 part by mass, 0.01 part by mass to 1 part by mass, or 0.01 part by mass to 0.1 part by mass relative to 100 parts by mass of the total amount of components (A) to (C).

[0149] [UV-curable organopolysiloxane composition]

[0150] The UV-curable organopolysiloxane composition of the present invention is characterized by comprising the components (A), (B) and (C) as essential components, substantially containing no organic solvent, and having a viscosity ranging from more than 80 mPas to 500 mPas or less as measured at 25° C. using an E-type viscometer for the entire composition. When the viscosity of the composition is within the range, the composition is excellent in its coating ability and a high-quality coating layer can be effectively obtained.

[0151] The viscosity of the entire composition is preferably in the range of 100 mPas to 500 mPas, more preferably 100 mPas to 350 mPas, particularly preferably 200 mPas to 350 mPas. In this embodiment, substantially free of organic solvent means that the content of organic solvent is less than 0.05% by mass of the entire composition, and the content is preferably below the detection limit determined using an analytical method such as gas chromatography. In the present invention, the desired viscosity of the composition can be achieved by controlling the molecular structure and molecular weight of component (A) and component (B).

[0152] In the curable composition of the present invention, the desired physical properties of the thus obtained cured body and its curing speed can be achieved, and the viscosity of the curable composition can be designed to have its desired value, depending on the molecular length of component (A) and component (B), the number of alkenyl groups or silicon atom-bonded hydrogen groups in each molecule, the binding position of these reactive functional groups in the molecule, and its molecular structure. In addition, the cured body obtained by curing the curable composition of the present invention is also included in the scope of the present invention.

[0153] The hardness of the cured body of the present invention (its hardness measured at 25° C. by a D-type durometer) is preferably 30 or greater. Since the cured body having the hardness can be used as a stamp material having good demolding properties for cured optical products, such as products having patterns by nanoimprint lithography, it helps to improve the productivity in the nanoimprint lithography process. On the other hand, when the hardness of the cured body is too high, this may unfavorably increase its brittle characteristics, resulting in lower productivity. The preferred D-type durometer hardness in the cured body of the present invention is 30 or greater and 70 or less.

[0154] There is no particular restriction on the form of the solidified body obtained by curing the composition of the present invention, and the solidified body may be in the form of a film-like coating layer, may be a sheet-like molded product, and may be a filling material obtained by curing by injecting into a specific position in an uncured state. In addition, the solidified body can be used as a sealing material or applied to an intermediate layer of a laminate or a display device, etc. The solidified body obtained by the composition of the present invention is preferably a coating layer in the form of a film, a film-like molding material, and particularly preferably a film-like insulating molding material.

[0155] The curable composition of the present invention is suitable for use as an insulating coating agent, a potting agent or a molding material having a film shape for electronic and electrical devices, and is particularly suitable for use as a stamp applied to a nanoimprint lithography process.

[0156] [Other additives]

[0157] If necessary, various additives can be added to the composition of the present invention. Examples of usable additives include release agents, leveling agents, UV absorbers, antioxidants, fillers (reinforcement fillers, insulating fillers, thermal conductive fillers and other functional fillers), etc. In addition, particularly when used as a potting agent or sealant, a thixotropy imparting agent can be added to the composition of the present invention if necessary.

[0158] The composition can be prepared by uniformly mixing components (A) to (C) and other components (if necessary). When preparing the composition, it can be mixed at room temperature using various stirrers or kneaders, and can be mixed while applying heating if necessary. There is no particular restriction on the order of adding each component. They can be mixed in any order.

[0159] Furthermore, in view of its storage stability, the composition may be a one-component type composition, and may be a multi-component type composition such as a two-component type composition that is mixed before use. Specifically, when in a two-component type composition, it is preferred that the first component contains a part of the component (A) and the catalytic component (C), and the second component contains a part of the component (A) and the bridging component (B). Furthermore, although other optional components may be added to any component, from the viewpoint of reactivity when all components are mixed, it is preferred that the hydrosilylation reaction inhibitor is added to the second component containing the component (B).

[0160] The composition can be cured at a relatively low temperature range including room temperature (e.g., a range of 15° C. to 80° C.) after irradiation with high energy rays such as UV rays. In addition, the curing reaction of the composition can be controlled at a desired speed by the content of the catalytic metal in component (C), the type and amount of the hydrosilylation reaction inhibitor.

[0161] [application]

[0162] The UV-curable organopolysiloxane composition of the present invention is curable not only by ultraviolet rays but also by electron beams, which is another aspect of the present invention.

[0163] The viscosity of the curable composition of the present invention is low, and can be used as the formation material of the insulating layer of electronic and electrical devices, and as the stamp applied to the nanoimprint lithography process. The curable composition of the present invention can be applied to the substrate or the interlayer between two substrates (at least one of which contains the material that allows ultraviolet rays or electron beams to pass through), and the composition is cured to form an insulating layer by irradiating ultraviolet rays or electron beams. In this case, when the composition of the present invention is applied to the substrate, it can be patterned, and then the composition can be cured. Alternatively, the composition can be applied to the substrate, and during the curing period, the cured part and the uncured part are left by ultraviolet rays or electron beam irradiation. Then, the uncured part can be removed with a solvent to form an insulating layer with a desired pattern.

[0164] Because the transparency of the solidified body thus obtained is good, the curable composition of the present invention is suitable as a material for forming an insulating layer of a touch panel, a display, and other display devices. In this case, if necessary, any desired pattern can be formed on the insulating layer as described above. In addition, since the solidified body thus obtained has high hardness and demolding properties, it is suitable as a stamp material applied to a nanoimprint lithography process.

[0165] In addition, the curable composition can also be used to form an insulating coating layer (insulating film) by curing after the coated product. 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 layer. Moreover, the cured body obtained by curing the curable composition of the present invention can be used as an insulating coating layer, an insulating potting agent for electronic and electrical devices, and a stamp material applied to a nanoimprint lithography process.

[0166] The present invention is further described below based on examples, but the present invention is not limited to the following examples.

[0167] Example

[0168] The UV-curable organopolysiloxane composition of the present invention and the cured product thereof are described in detail based on Examples. In addition, the measurements and evaluations in Examples and Comparative Examples were performed as follows.

[0169] [Viscosity of Organopolysiloxane and Curable Organopolysiloxane Composition]

[0170] The viscosity (mPa·s) at 25° C. was measured using a rotational viscometer (E-type viscometer VISCONIC EMD manufactured by TOKIMEC CORPORATION).

[0171] [Preparation of Curable Organopolysiloxane Composition]

[0172] Each material in an amount listed in the following Table 1 was placed in a brown plastic container and thoroughly mixed using a planetary mixer to prepare a curable organopolysiloxane composition.

[0173] [Preparation of Cured Body from Curable Organopolysiloxane Composition]

[0174] About 0.65 g of the curable organopolysiloxane composition was poured between two glass substrates having a spacer having a thickness of 1 mm. Through one glass substrate, 4000 mJ / cm 2 LED light having a wavelength of 365 nm was irradiated onto the composition at an energy exposure amount of 100 Å, and the composition was cured by subsequent heating at 80° C. in an oven for 30 minutes, thereby preparing a plate-shaped organopolysiloxane cured body having 25 mm per side and 1 mm in thickness.

[0175] [Appearance of Cured Body Obtained from Curable Organopolysiloxane Composition]

[0176] The appearance of the plate-like organopolysiloxane cured body obtained by the above method was visually evaluated.

[0177] [Hardness of Cured Body Obtained from Curable Organopolysiloxane Composition]

[0178] Four sheets of the plate-like organopolysiloxane cured body obtained by the aforementioned method were laminated, and the D-type durometer hardness was measured at 25° C. using a digital durometer (Asker automatic rubber hardness meter manufactured by KOUBUNSHI-KEIKI CORPORATION).

[0179] [Toughness of Cured Body Obtained from Curable Organopolysiloxane Composition]

[0180] After the hardness measurement, the upper layer of the solidified body was visually inspected, and the toughness of the solidified body was evaluated by the following criteria:

[0181] "Good" No changes in appearance were observed,

[0182] "NG1" Slight cracks were observed from the contact point of the needle tip of the hardness tester.

[0183] Obvious cracks were observed in “NG2”.

[0184] [Examples and Comparative Example 1]

[0185] UV-curable organopolysiloxane compositions of the compositions (parts by mass) shown in Table 1 were prepared using the following components.

[0186] (A1) is composed of (Me3SiO 1 / 2 ) 0.38(Me2ViSiO 1 / 2 ) 0.08 (SiO 4 / 2 ) 0.54 The branched organopolysiloxane represented by has a molecular weight of 6,000.

[0187] (A2a) is composed of (Me3SiO 1 / 2 ) 0.48 (Me2ViSiO 1 / 2 ) 0.14 (SiO 4 / 2 ) 0.38 The branched organopolysiloxane represented by has a molecular weight of 1,200.

[0188] (A2b) is composed of (Me2ViSiO 1 / 2 ) 0.8 (SiO 4 / 2 ) 0.2 The branched organopolysiloxane represented by has a molecular weight of 432.

[0189] (A3) dimethyl polysiloxane terminated with dimethyl vinyl siloxy groups at both ends of the molecular chain, with a viscosity of 60 mPas

[0190] (B1) MQ-type branched organopolysiloxane having a dimethylhydrogensiloxy group and a hydrogen content of 1.0 mass%

[0191] (B2) Polymethylhydrogensiloxane having a hydrogen content of 1.4% by mass and end-capped with trimethylsiloxy groups at both ends of the molecular chain

[0192] (C) (Cyclopentadienyl)trimethylplatinum(IV) complex

[0193] [Table 1]

[0194]

[0195] As shown in Table 1, the UV-curable organopolysiloxane composition of the present invention (Examples 1 to 6) has a viscosity suitable for being applied to a substrate as a coating agent by spin coating or other coating procedures at 25°C, and has high transparency. The cured product obtained by UV irradiation and subsequent heating is transparent and has a sufficiently high hardness. Therefore, the UV-curable organopolysiloxane composition of the present invention and the cured body obtained therefrom are suitable as a stamp material applied to a nanoimprint lithography process. On the other hand, a composition with too low viscosity (Comparative Example 2, Comparative Example 3) cannot provide a cured body with sufficient toughness. In addition, in the composition lacking component (A2) (Comparative Example 4), the hardness of the cured body obtained therefrom is insufficient. Moreover, when the alkenyl content of the composition (Comparative Example 1) is outside a specific range, the viscosity is too high and is not suitable as a coating agent.

[0196] Industrial Applicability

[0197] The UV-curable organopolysiloxane composition of the present invention is particularly suitable for the applications described above, and in particular as a material for forming a stamp material applied to a nanoimprint lithography process.

Claims

1. An ultraviolet (UV)-curable organopolysiloxane composition, the UV-curable organopolysiloxane composition comprising (A) an alkenyl-functional organopolysiloxane mixture comprising the following component (A1), component (A2) and component (A3): (A1) a branched organopolysiloxane having two or more alkenyl groups in one molecule and having a molecular weight of 2,500 or more; (A2) a branched organopolysiloxane having two or more alkenyl groups in one molecule and a molecular weight of less than 2,500; and (A3) a linear organopolysiloxane having two or more alkenyl groups in one molecule; (B) an organopolysiloxane having two or more silicon-bonded hydrogen atoms in one molecule, in an amount ranging from 0.5 to 4.0 in a molar ratio of the silicon-bonded hydrogen atoms in the component (B) relative to the alkenyl groups in the component (A); and (C) a photoactivatable hydrosilylation catalyst; The mass ratio of component (A1), component (A2) and component (A3) satisfies the following formula (1): [(A1)+(A2)] / (A3) > 1.3 (1) The content X of alkenyl groups per 100 g of the entire composition satisfies the following formula (2): 110 ≤ X ≤ 220 (2) The viscosity of the entire composition measured at 25° C. using an E-type viscometer ranges from more than 80 mPas to 500 mPas or less, and The composition is substantially free of organic solvents.

2. The UV-curable organopolysiloxane composition according to claim 1, wherein the mass parts of component (A1), component (A2) and component (A3) satisfy the following conditions: (A1): 25 to 75 parts by mass; (A2): 3 parts by mass to 60 parts by mass; and (A3): 5 to 40 parts by mass; The total mass of components (A) to (C) in the composition is 100 parts by mass.

3. The UV-curable organopolysiloxane composition according to claim 1, wherein component (A3) is a linear organopolysiloxane having an alkenyl group at a molecular terminal thereof.

4. The UV-curable organopolysiloxane composition of claim 1, wherein component (B) is a linear organopolysiloxane having two or more silicon-bonded hydrogen atoms in the molecule.

5. The UV-curable organopolysiloxane composition according to claim 1, wherein component (A1) is a branched organopolysiloxane having an alkenyl group and represented by the following average unit formula: (R 1 3SiO 1 / 2 ) a1 (R 1 2SiO 2 / 2 ) b1 (R 1 SiO 3 / 2 ) c1 (SiO 4 / 2 ) d1 (3) (where R 1 are independently monovalent hydrocarbon groups having 1 to 12 carbon atoms, All R 1 At least two of them are alkenyl groups having 2 to 12 carbon atoms, and a1, b1, c1 and d1 are values ​​satisfying the following conditions: a1+b1+c1+d1=1, 0≤a1≤0.5, 0≤b1≤0.4, 0≤c1≤0.8, and 0≤d1≤0.7, 0.5≤c1+d1≤0.8).

6. The UV-curable organopolysiloxane composition according to claim 1, wherein component (A2) is a branched organopolysiloxane having an alkenyl group and represented by the following average unit formula: (R 2 3SiO 1 / 2 ) a2 (R 2 2SiO 2 / 2 ) b2 (R 2 SiO 3 / 2 ) c2 (SiO 4 / 2 ) d2 (4) (where R 2 are independently monovalent hydrocarbon groups having 1 to 12 carbon atoms, All R 2 At least two of them are alkenyl groups having 2 to 12 carbon atoms, and a2, b2, c2 and d2 are values ​​satisfying the following conditions: a2+b2+c2+d2=1, 0≤a2≤0.5, 0≤b2≤0.8, 0≤c2<0.5, and 0≤d2<0.5, 0≤ <c2+d2<0.5)。 7. The UV-curable organopolysiloxane composition according to claim 1, wherein the mass ratio of component (A1), component (A2) and component (A3) satisfies the following formula (5): [(A1)+(A2)] / (A3) ≥ 1.5 (5).

8. The UV-curable organopolysiloxane composition according to any one of claims 1 to 7, wherein the hardness of the cured body obtained by curing the composition measured at 25°C using a type D durometer is 30 or more.

9. The UV-curable organopolysiloxane composition according to any one of claims 1 to 8, wherein the viscosity of the entire composition measured at 25°C using an E-type viscometer ranges from 100 mPas to 350 mPas.

10. The UV-curable organopolysiloxane composition according to any one of claims 1 to 9, wherein component (C) is an unsubstituted or alkyl-substituted (cyclopentadienyl)trialkylplatinum complex. 11 . An insulating coating agent comprising the UV-curable organopolysiloxane composition according to claim 1 .

12. A cured body obtained by curing the UV-curable organopolysiloxane composition according to any one of claims 1 to 10.

13. Use of the UV-curable organopolysiloxane composition according to any one of claims 1 to 10 as a stamp-forming material for application in nanoimprint lithography.

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