Ultraviolet-curable organomodified silicone composition and cured product

Abstract

An ultraviolet-curable organo-modified silicone composition containing (A) a polymer represented by formula (1) [in the formula, each X is independently a divalent group represented by formula (2), each Y is independently a monovalent group represented by any one of formulas (3) to (5), each Y' is independently a divalent group represented by formula (6) or (7), and m is an integer of 0 to 12], (B) an organosilicon compound having at least three hydrogen atoms bonded to terminal silicon atoms in one molecule, and (C) a platinum group metal catalyst activated with light having a wavelength of 200 to 500 nm, and not having an organic hydrosiloxane unit represented by formula (1) (in the formula, R represents an organic group). 2 / 2 An ultraviolet-curable organo-modified silicone composition containing (A) a polymer represented by formula (1) [in the formula, each X is independently a divalent group represented by formula (2), each Y is independently a monovalent group represented by any one of formulas (3) to (5), each Y' is independently a divalent group represented by formula (6) or (7), and m is an integer of 0 to 12], (B) an organosilicon compound having at least three hydrogen atoms bonded to terminal silicon atoms in one molecule, and (C) a platinum group metal catalyst activated with light having a wavelength of 200 to 500 nm, and not having an organic hydrosiloxane unit represented by formula (1) (in the formula, R represents an organic group).

Description

TECHNICAL FIELD

[0001] The present application relates to an ultraviolet-curable organomodified silicone composition and a cured product thereof, and more particularly to an ultraviolet-curable organomodified silicone composition and a cured product thereof which are useful as a material for optical devices or optical parts, an insulating material for electronic devices or electronic parts, a coating material, an adhesive, a mold material for nanoimprint applications, and the like. BACKGROUND

[0002] Organomodified silicones such as alkylene-modified silicones and arylene-modified silicones have characteristics such as high hardness, high toughness, and high gas barrier properties compared to dimethyl silicones. Due to these characteristics, organomodified silicones are used as coating materials for electronic components and sealing materials for light emitting diodes.

[0003] On the other hand, in the case of organomodified silicones, it is necessary to cure them using an addition crosslinking reaction, and in order to obtain a cured product with sufficient hardness, it is necessary to heat and cure at a high temperature of 150°C or the like for several hours. Thus, there are difficulties in applications in which the size of the device is large and it is difficult to load into a curing oven, and in applications in which low-temperature curability is required for reasons of heat resistance of the device, and the like.

[0004] In contrast, ultraviolet-curable addition-curable silicones use a platinum catalyst of the ultraviolet-active type, and crosslinking is performed starting with irradiation with ultraviolet rays, and thus curing can be performed at a relatively low temperature. In addition, since there is no oxygen curing hindrance, it is not necessary to have a process of replacing the inside of the system with an inactive gas at the time of curing and equipment therefor.

[0005] Hitherto, it has been known that a composition containing an addition polymer of vinyl norbornene and bis(dimethylsilyl)benzene and an organohydrogenpolysiloxane can be used as an ultraviolet-active addition-curable material (Patent Document 1).

[0006] However, in this material, the curability after ultraviolet irradiation is insufficient, and in order to obtain a cured product, post-curing is required.

[0007] PRIOR ART DOCUMENTS

[0008] PATENT DOCUMENTS

[0009] Patent Document 1: Japanese Patent Application Publication No. 2019-108471 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] The present application was made in view of the above circumstances, and aims to provide an ultraviolet-curable organomodified silicone composition which rapidly performs curing using a hydrosilylation reaction after ultraviolet irradiation, and can form a cured product with high hardness without the need for post-curing.

[0012] Means for solving the problems

[0013] The present inventors have conducted intensive studies in order to solve the above problems, and as a result, have found that the following composition rapidly cures upon irradiation of ultraviolet rays, and forms a cured product having excellent hardness, thereby completing the present invention.

[0014] That is, the present invention provides:

[0015] 1. An ultraviolet-curable organomodified silicone composition, comprising:

[0016] (A) a polymer represented by the following structural formula (1):

[0017] [Chemical Formula 1]

[0018]

[0019] [In the formulae, each X is independently a divalent group represented by the following structural formula (2), each Y is independently a monovalent group represented by any one of the following structural formulae (3) to (5), each Y' is independently a divalent group represented by the following structural formula (6) or (7), and Me represents a methyl group. m is an integer of 0 to 12.

[0020] [Chemical Formula 2]

[0021]

[0022] (In the formulae, the asterisk (*) represents a bonding site to a silicon atom.)

[0023] [Chemical Formula 3]

[0024]

[0025] (In formulae (3) to (7), the asterisk (*) represents a bonding site to a silicon atom, and the stereo configuration of each chiral carbon can be either of cis (exo) or trans (endo).)

[0026] (B) an organosilicon compound having at least three hydrogen atoms bonded to a terminal silicon atom in one molecule, and

[0027] (C) a platinum group metal catalyst activated with light having a wavelength of 200 to 500 nm,

[0028] and does not have an organohydrogensiloxane unit represented by HRSiO 2 / 2 (In the formula, R represents an organic group.)

[0029] 2. The ultraviolet-curable organomodified siloxane composition according to 1, wherein the (B) component comprises a compound represented by the following formula (I), an addition reaction product of phenyltrivinylsilane represented by the following formula (II) and 1,4-bis(dimethylsilyl)benzene, or both,

[0030] [Chem. 4]

[0031]

[0032] [Chem. 5]

[0033]

[0034] (In formula (II), n is an integer of 1 to 20.)

[0035] 3. The ultraviolet-curable organomodified siloxane composition according to 1 or 2, wherein the (C) component comprises (η 5 a cyclopentadienyl group) trisfatty aliphatic platinum compound or a bis(β-diketonato) platinum compound,

[0036] 4. A cured product of the ultraviolet-curable organomodified siloxane composition according to any one of 1 to 3.

[0037] Effects of the Invention

[0038] According to the present invention, an organomodified siloxane resin cured product having sufficient hardness can be obtained in a short time, and thus technical or production problems possessed by conventional materials can be solved. In addition, since curing can be performed at room temperature, the present invention can be applied to substrates having low heat resistance.

[0039] Therefore, the ultraviolet-curable organomodified siloxane composition of the present invention can be used as a material for optical devices or optical members, an insulating material for electronic devices or electronic members, a coating material, an adhesive, a mold material for nanoimprinting, and the like. DETAILED DESCRIPTION

[0040] The present invention will be specifically described below.

[0041] [1] (A) Component

[0042] The (A) component in the ultraviolet-curable organosilicon resin composition of the present invention is a polymer represented by the following structural formula (1).

[0043] [Chem. 61

[0044]

[0045] In formula (1), each X is independently a divalent group represented by the following structural formula (2), each Y is independently a monovalent group represented by any one of the following structural formulas (3) to (5), each Y' is independently a divalent group represented by the following structural formula (6) or (7), and Me represents a methyl group (the same applies hereinafter).

[0046] [Chemical Formula 7]

[0047]

[0048] (In the formula, an asterisk (*) indicates a bonding site to a silicon atom.)

[0049] [Chemical Formula 8]

[0050]

[0051] (In formulas (3) to (7), an asterisk (*) indicates a bonding site to a silicon atom, and the stereo configuration of each chiral carbon can be either cis (exo) or trans (endo).)

[0052] Note that the bonding direction of the divalent group represented by the above structural formula (6) or (7) is not limited to that described above, and includes a structure in which each structure is rotated 180° on the paper surface.

[0053] In addition, m is an integer of 0 to 12, and is preferably 1 to 5. When m exceeds 12, the liquid becomes highly viscous at normal temperature, and is difficult to handle.

[0054] The kinematic viscosity of the (A) component is not particularly limited, and is preferably 1000 to 100000 mm 2 / s, and more preferably 5000 to 30000 mm 2 / s. Note that in the present application, the kinematic viscosity is a value at 23°C measured using a Cannon-Fenske type viscometer (the same applies hereinafter).

[0055] The (A) component can be produced according to a known method (Japanese Patent Application Publication No. 2005-133073, etc.) as, for example, an addition reaction product of (a) bis(dimethylsilyl)benzene and (b) vinyl norbornene.

[0056] The (a) component is a bis(dimethylsilyl)benzene substituted at the ortho position, meta position, or para position represented by the following structural formula (8), and a single structure can be used, or a mixture of two or more isomers can be used.

[0057] [Chemical Formula 9]

[0058]

[0059] (b) Component is 5-vinylbicyclo[2.2.1]hept-2-ene represented by the following structural formula (9), a single structure can be used, or a mixture of two or more isomers can be used.

[0060] [Chemical Formula 10]

[0061]

[0062] The (A) component of the present application can be obtained, for example, by allowing the (b) component having two addition-reactive carbon-carbon double bonds in one molecule to be present in an excess of 1 mole or more and 10 moles or less, preferably 1 mole or more and 5 moles or less, per 1 mole of the (a) component having two SiH groups in one molecule, in the presence of a hydrosilylation reaction catalyst.

[0063] As the hydrosilylation reaction catalyst, a publicly known catalyst can be used. For example, platinum-based catalysts such as carbon powder supported with platinum metal, platinum black, platinum chloride, chloroplatinic acid, a reaction product of chloroplatinic acid with monohydric alcohol, a complex of chloroplatinic acid with olefins, platinum bis(acetylacetonate), and the like; palladium-based catalysts, rhodium-based catalysts, and the like platinum group metal-based catalysts, and the like can be exemplified. In addition, the addition reaction conditions, the use of solvents, and the like are not particularly limited, and the reaction can be performed under publicly known conditions.

[0064] As described above, in the production of the (A) component, the (b) component is used in an excess molar amount relative to the (a) component, and therefore the (A) component has two addition-reactive carbon-carbon double bonds from the (b) component in one molecule.

[0065] In addition, in the case where a compound having an addition-reactive carbon-carbon double bond is used as the (B) component or the like described later, the proportion of the addition-reactive carbon-carbon double bond from the (A) component in the total of the addition-reactive carbon-carbon double bonds in the composition of the present application is preferably 20 to 100 mole%, more preferably 40 to 100 mole%.

[0066] The above (A) component can be used singly or in combination of two or more.

[0067] [2] (B) Component

[0068] The (B) component of the present application is an organosilicon compound having at least three hydrogen atoms (hydrogensilyl groups) bonded to terminal silicon atoms. Such terminal hydrogensilyl groups have high reactivity in hydrosilylation reaction, and therefore the formation of three-dimensional crosslinks proceeds rapidly, and a cured product having high hardness is formed.

[0069] In addition, the (B) component is an organohydrogensiloxane unit (D) represented by the following formula: 2 / 2 (In the formula, R represents an organic group.)H The silicone compound of the present application is exemplified by a compound represented by the following formula (I), an addition reaction product of phenyltrivinylsilane and 1,4-bis(dimethylsilyl)benzene represented by the following formula (II), a compound represented by the following formula (III), and the like.

[0070] [Chem. 11]

[0071]

[0072] [Chem. 12]

[0073]

[0074] (In formula (II), n is an integer of 1 to 20, preferably an integer of 1 to 10, and the dotted line indicates a bonding end.)

[0075] [Chem. 13]

[0076]

[0077] The kinematic viscosity of the component (B) is not particularly limited, and is preferably 0.1 to 100,000 mm 2 / s, more preferably 0.1 to 3,000 mm 2 / s, further preferably 0.5 to 500 mm 2 / s.

[0078] The compounding amount of the component (B) is preferably an amount in which the amount of hydrogen atoms bonded to silicon atoms becomes 0.5 to 1.5 moles with respect to 1 mole of the addition reaction carbon-carbon double bond of the component (A) in the composition of the present application, and more preferably an amount in which it becomes 0.8 to 1.2 moles.

[0079] The above component (B) can be used alone or in combination of two or more.

[0080] [3] Component (C)

[0081] The platinum group metal catalyst for the hydrosilylation reaction of the component (C) is a platinum catalyst which is inactive under light shielding and becomes active by irradiation of light having a wavelength of 200 to 500 nm, and is used for catalyzing the hydrosilylation reaction of the addition reaction carbon-carbon double bond in the component (A) and the hydrogen atoms bonded to silicon atoms in the component (B).

[0082] As a specific example of such a component (C), there can be mentioned (η 5 - cyclopentadienyl)trisfatty platinum compound, derivatives thereof, and the like.

[0083] Of these, particularly preferable are cyclopentadienyltrimethylplatinum complex, methylcyclopentadienyltrimethylplatinum complex, and derivatives in which the cyclopentadienyl group thereof is modified.

[0084] Further, bis(β-diketonato)platinum compounds are also listed as examples of the preferred (C) component, of which bis(acetylacetonato)platinum compounds and derivatives in which the acetylacetonato group thereof is modified are particularly preferable.

[0085] The compounding amount of the (C) component is not limited as long as it is an amount that promotes the curing (hydrosilylation reaction) of the present composition, and it is preferable that the platinum group metal atom in the present component be in the range of 0.01 to 500 ppm in mass units, relative to the total mass of the (A) component and the (B) component of the present composition, more preferably in the range of 0.05 to 100 ppm, and further preferably in the range of 0.01 to 50 ppm.

[0086] The above (C) component can be used alone or in combination with two or more.

[0087] [4] (D) Component

[0088] In the composition of the present application, in order not to cause thickening or gelation before heat curing when the composition is formulated or applied on a substrate, a reaction control agent of the (D) component can be added as necessary.

[0089] As specific examples thereof, 3-methyl-1-butyne-3-ol, 3-methyl-1-pentyne-3-ol, 3,5-dimethyl-1-hexyne-3-ol, 1-ethynylcyclohexanol, ethynylmethyldecylcarbinol, 3-methyl-3-trimethylsilyloxy-1-butyne, 3-methyl-3-trimethylsilyloxy-1-pentyne, 3,5-dimethyl-3-trimethylsilyloxy-1-hexyne, 1-ethynyl-1-trimethylsilyloxycyclohexane, bis(2,2-dimethyl-3-butyloxy)dimethylsilane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,1,3,3-tetramethyl-1,3-divinyl disiloxane, and the like can be given.

[0090] Of these, 1-ethynylcyclohexanol, ethynylmethyldecylcarbinol, 3-methyl-1-butyne-3-ol, and bis(2,2-dimethyl-3-butyloxy)dimethylsilane are preferable.

[0091] The compounding amount of the (D) component is preferably 0.01 to 2.0 parts by mass, and more preferably 0.01 to 0.1 parts by mass, relative to 100 parts by mass of the total of the (A) component and the (B) component. If it is in this range, the effect of the reaction control is sufficiently exerted.

[0092] In addition, the ultraviolet-curable organomodified siloxane composition of the present application has substantially no HRSiO 2 / 2 units represented by the formula: R H units represented by the formula: R

[0093] [5] Other Components

[0094] The composition of the present application can contain other components exemplified below, in addition to the above-mentioned components (A) to (C) and the component (D) used as necessary, without impairing the object of the present application.

[0095] For example, adhesion-imparting agents having one or more functional groups consisting of alkenyl group, (meth)acryloyl group, carbonyl group, epoxy group, alkoxysilyl group, amido group in one molecule; thixotropy-controlling agents such as fumed silica; reinforcing agents such as crystalline silica; antioxidants such as hindered phenol, hindered amine; light stabilizers; heat resistance-improving agents such as metal oxides, metal hydroxides; colorants such as titanium oxide; thermally-conductivity-imparting fillers such as alumina, crystalline silica; viscosity-adjusting agents such as non-reactive silicone oils not having reactive functional groups; electrically-conductivity-imparting agents such as metal powders such as silver, gold; pigments, dyes for coloring.

[0096] The ultraviolet-curable organomodified siloxane composition of the present application can be used for various substrates, and can be used for materials for optical devices or optical parts, insulating materials for electronic devices or electronic parts, coating materials, mold materials for nanoimprinting, and the like.

[0097] As the substrate, a substrate used in the fields of coating, casting, bonding and sealing of housings or members for composite materials, metal members, plastic members, ceramic members, quartz glass, electrical applications, electronic applications, optical applications, and the like can be used.

[0098] The composition of the present application can also be used for substrates activated by a publicly-known pretreatment process such as primer treatment, plasma treatment, excimer light treatment, and the like.

[0099] At the time of curing of the ultraviolet-curable organomodified siloxane composition of the present application, a UV-LED lamp, a metal halide lamp, a mercury lamp, or the like can be used, and light having a wavelength of 200 to 500 nm, preferably 200 to 370 nm, is used in the photoactivation of the platinum catalyst.

[0100] From the viewpoint of the curing speed of the composition and the prevention of discoloration, the irradiation intensity is preferably 30 to 2000 mW / cm 2 , and the irradiation dose is preferably 3000 to 100000 mJ / cm2 The temperature at the time of irradiation is preferably 10 to 60°C, more preferably 20 to 40°C.

[0101] Examples

[0102] The present application is specifically described below by citing examples and comparative examples, but the present application is not limited to the following examples. Note that in the following formulae, Ph represents a phenyl group.

[0103] [Examples 1 to 3, Comparative Examples 1 to 4]

[0104] The following (A) to (D) components were mixed at the compounding amounts (parts by mass) shown in Table 1 to prepare an ultraviolet-curable organomodified silicone composition.

[0105] (A) Component

[0106] m in the above structural formula (1) is a mixture of polymers having a value of 1 to 5 (content ratio of addition-reactive carbon-carbon double bonds: 0.47 mol / 100 g)

[0107] (B) Component

[0108] (B-1) A compound represented by the following structural formula (I) (kinematic viscosity at 23°C: 1.8 mm 2 / s, content of silicon atom-bonded hydrogen atoms: 0.0092 mol / g)

[0109] [Chemical 141

[0110]

[0111] (B-2) A mixture of compounds represented by the following structural formulae (a) to (d) [(a):(b):(c):(d) = 55:25:10:15 (molar ratio), kinematic viscosity at 23°C: 30000 mm 2 / s, average content of silicon atom-bonded hydrogen atoms: 0.0035 mol / g]

[0112] [Chemical 15]

[0113] (a)

[0114]

[0115] [Chemical 16]

[0116] (b)

[0117]

[0118] [Chemical 17]

[0119] (c)

[0120]

[0121] [Chem. 18]

[0122] (d)

[0123]

[0124] (n = 4 to 10, dotted line indicates bonding end.)

[0125] (B-3) Compound represented by the following structural formula (kinetic viscosity at 23°C: 21.4 mm 2 / s, content of silicon atom-bonded hydrogen atoms: 0.0069 mol / g)

[0126] [Chem. 19]

[0127]

[0128] (In the formula, the arrangement of each siloxane unit in parentheses is random, alternating, or block)

[0129] (B-4) Compound represented by the following structural formula (kinetic viscosity at 23°C: 65 mm 2 / s, content of silicon atom-bonded hydrogen atoms: 0.0116 mol / g)

[0130] [Chem. 20]

[0131]

[0132] (In the formula, the arrangement of each siloxane unit in parentheses is random, alternating, or block)

[0133] (C) Component

[0134] Toluene solution of methylcyclopentadienyl trimethyl platinum complex having a content of platinum element of 0.5 mass%

[0135] (D) Component

[0136] Bis(2,2-dimethyl-3-butyneoxy)dimethylsilane

[0137] [State of curing of composition]

[0138] For each of the obtained compositions 8 g, UV rays were irradiated at room temperature (23°C) in such a manner that the irradiation intensity becomes 100 mW / cm 2 and the dose becomes 30,000 mJ / cm 2 , using a UV-LED lamp of wavelength 365 nm, and the state of curing of the composition immediately after the irradiation was completed was judged by touch.

[0139] In addition, the hardness of the cured product at 23°C was evaluated with a JIS hardness tester, Durometer type. The results are collectively shown in Table 1.

[0140] [Table 1]

[0141]

[0142] As shown in Table 1, it was found that the compositions prepared in Examples 1 to 3 were cured rapidly after irradiation with ultraviolet rays at 23°C, and formed cured products having high hardness.

[0143] On the other hand, it was found that the compositions prepared in Comparative Examples 1 to 4 did not cure immediately after irradiation with ultraviolet rays.

Claims

1. An ultraviolet-curable organomodified silicone composition which is capable of forming a cured product without post-curing, and which contains: (A) a polymer represented by the following structural formula (1): [Chemical Formula 1] ###0001### wherein each X is independently a divalent group represented by the following structural formula (2), each Y is independently a monovalent group represented by any one of the following structural formulas (3) to (5), each Y' is independently a divalent group represented by the following structural formula (6) or (7), Me represents a methyl group, and m is an integer of 0 to 12, [Chemical Formula 2] ###0002### wherein an asterisk * represents a bonding site to a silicon atom, [Chemical Formula 3] ###0003### [Chemical Formula 4] ###0004### [Chemical Formula 5] ###0005### wherein an asterisk * represents a bonding site to a silicon atom, and the stereo configuration of each chiral carbon is either cis, i.e., exo, or trans, i.e., endo, (B) a silicone compound having at least three hydrogen atoms bonded to a terminal silicon atom in one molecule, and (C) a platinum group metal catalyst activated with light having a wavelength of 200 to 500 nm, the (B) component contains a compound represented by the following formula (I), an addition reaction product of phenyltrivinylsilane represented by the following formula (II) and 1,4-bis(dimethylsilyl)benzene, or both: [Chemical Formula 6] ###0006### [Chemical Formula 7] ###0007### wherein n is an integer of 1 to 20.

4. A cured product of the ultraviolet-curable organomodified silicone composition according to any one of claims 1 to 3. ​ ​ ​ ​ ​ ​ ​ ​ Further, the ultraviolet-curable organic-modified silicone composition does not have an organic hydrosiloxane unit represented by the formula of R 2 / 2 wherein R represents an organic group.

2. The ultraviolet-curable organomodified siloxane composition according to claim 1, wherein ​ ​ ​ ​ 3. The ultraviolet-curable organomodified siloxane composition according to claim 1 or 2, wherein The (C) component comprises (η 5 - a (cyclopentadienyl)tri-aliphatic platinum compound or a bis(β-diketonato) platinum compound. ​

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