Organopolysiloxane composition, cured product, and laminate

Abstract

[Solution] An organopolysiloxane composition characterized by containing the following components (A) to (C). (A) A linear organopolysiloxane containing an alkenyl group bonded to a silicon atom. (B) An organohydrogenpolysiloxane containing a hydrogen atom bonded to a silicon atom. (C) A platinum group metal catalyst represented by formula (1). Thus, provided is an organopolysiloxane composition which can be stored for a long period of time shielded from light at room temperature (approximately 25-40°C) and which can be rapidly crosslinked by ultraviolet irradiation.

Description

Organopolysiloxane compositions, cured products, and laminates

[0001] The present invention relates to organopolysiloxane compositions, cured products thereof, and laminates.

[0002] Electronic devices with image display capabilities, such as displays and touch panels, generally consist of a protective cover panel with excellent light transmittance, made of highly transparent resins such as acrylic or polycarbonate, or glass, and an image display unit equipped with polarizing plates and image display elements on a substrate. Between these cover panels and the image display unit, an optically transparent resin layer is often placed to improve visibility and mechanical strength.

[0003] As the optically transparent resin layer described above, an ultraviolet-curable transparent organopolysiloxane adhesive composition has been proposed (Patent Document 1). Since this adhesive composition undergoes a gradual curing reaction by a platinum catalyst triggered by ultraviolet irradiation, a processing method can be employed in which the adhesive composition is applied to the polarizing plate of the image display section, and the cover panel is bonded after ultraviolet irradiation. This offers advantages such as enabling use in areas that are not irradiated with ultraviolet light (dark areas), such as under the bezel, and allowing the use of cover panels containing ultraviolet absorbers to provide weather resistance.

[0004] For UV-curable organopolysiloxane compositions, platinum group metal complexes that are activated by UV irradiation and exhibit rapid crosslinking properties are primarily used as catalysts.

[0005] Examples of such platinum group metal complexes include (trimethyl)cyclopentadienyl platinum (IV) and derivatives in which one of the hydrogen atoms bonded to the carbon atom of the cyclopentadienyl group is substituted with an alkyl or aryl group, and bis(acetylacetonate)platinum (II) and derivatives in which the hydrogen atom bonded to the carbon atom of the acetylacetonate group is substituted with an alkyl group (Patent Documents 2-6).

[0006] UV-curable organopolysiloxane compositions are required to remain uncrosslinked during storage (when protected from light) and to crosslink rapidly upon exposure to ultraviolet light. While the use of large amounts of reaction control agents, or so-called inhibitors, is known to achieve long pot life and good storage in the dark, there is generally a trade-off between pot life and crosslinking rate, and the use of inhibitors has the disadvantage of impairing the crosslinking rate.

[0007] On the other hand, UV-curable organopolysiloxane compositions that exhibit rapid crosslinking properties (i.e., do not require the use of large amounts of reaction control agents) increase in viscosity over time, requiring storage in a dark and cool place. However, storage in a cool place presents problems such as the need to install refrigeration equipment and space limitations.

[0008] In addition, a method is known in which the composition is divided into two liquid systems for storage and mixed before use. However, this method requires the introduction of stirring and defoaming equipment, and has problems such as the inability to achieve the expected physical properties if the mixing ratio deviates from the specified ratio.

[0009] Japanese Patent Publication No. 2015-110752, Japanese Patent Publication No. 2020-522582, Japanese Patent Publication No. 2001-089491, Japanese Patent Publication No. 2020-158548, Japanese Patent Publication No. 2024-040726, Japanese Patent Publication No. 2016-150991

[0010] Conventional technologies have presented a problem in that UV-curable organopolysiloxane compositions have a trade-off relationship between pot life and crosslinking rate, making it difficult to achieve both simultaneously.

[0011] The present invention has been made to solve the above problems and aims to provide organopolysiloxane compositions, cured products, and laminates that can be stored for a long period of time at room temperature (generally around 25 to 40°C) under light shielding and that rapidly crosslink upon ultraviolet irradiation.

[0012] To solve the above problems, the present invention provides an organopolysiloxane composition characterized by containing the following components (A) to (C): (A) A linear organopolysiloxane containing an alkenyl group bonded to a silicon atom; (B) An organohydrogenpolysiloxane containing a hydrogen atom bonded to a silicon atom; (C) A platinum group metal catalyst represented by the following formula (1). (In the formula, M represents a platinum group metal. R １ ~R ８ Each of these independently represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

[0013] The above organopolysiloxane composition can be stored for a long period of time in the dark at a temperature of about 25 to 40°C and has rapid crosslinking properties upon ultraviolet irradiation. Furthermore, organopolysiloxane cured products and laminates obtained by curing such organopolysiloxane compositions are suitable for bonding, sealing, and other applications of optical devices such as image display devices.

[0014] In this case, it is preferable that the organopolysiloxane composition of the present invention has 0.2 to 10 hydrogen atoms bonded to the silicon atom in component (B) for each alkenyl group in component (A).

[0015] The organopolysiloxane composition having such a ratio of [number of Si-H groups] / [number of alkenyl groups] exhibits superior pot life and crosslinking properties.

[0016] Furthermore, the organopolysiloxane composition of the present invention contains the R in component (C) above. １ ~R ８ However, each is independently a methyl group or an ethyl group, and it is preferable that M is platinum.

[0017] The organopolysiloxane composition using such component (C) exhibits superior pot life.

[0018] Furthermore, it is preferable that the organopolysiloxane composition of the present invention has a platinum group metal concentration derived from component (C) of the above-mentioned component (A) of 0.01 to 100 ppm.

[0019] The organopolysiloxane composition having such a platinum group metal concentration can achieve both superior pot life and crosslinking properties.

[0020] Furthermore, it is preferable that the organopolysiloxane composition of the present invention has a viscosity increase rate of 10% or less after 4 weeks in a light-shielded environment at 40°C.

[0021] The organopolysiloxane composition having a viscosity increase rate within the above range will fully satisfy the required pot life.

[0022] The present invention provides an organopolysiloxane cured product obtained by curing the organopolysiloxane composition.

[0023] Such organopolysiloxane cured products can be suitably used for bonding, sealing, and other applications of optical devices such as image display devices.

[0024] Furthermore, the present invention provides a laminate in which a substrate and the organopolysiloxane cured product are laminated together.

[0025] The laminate of the present invention provides a laminate with excellent reliability.

[0026] As described above, the organopolysiloxane composition of the present invention can be stored for a long time at room temperature (generally around 25 to 40°C) under light-shielding conditions, thus offering excellent handling properties, and provides an organopolysiloxane composition that crosslinks rapidly upon ultraviolet irradiation. Furthermore, organopolysiloxane cured products and laminates obtained by curing such organopolysiloxane compositions are suitable for bonding, sealing, and other applications of optical devices such as image display devices.

[0027] As described above, there was a need to develop an organopolysiloxane composition that could be stored for long periods at room temperature under light-shielding conditions and that could be rapidly crosslinked by ultraviolet irradiation.

[0028] As a result of intensive studies on the above problems, the present inventor has found that an organopolysiloxane composition containing the following components (A), (B) and (C) can have a long pot life, that is, can be stored for a long time under normal temperature and light shielding, and can achieve a rapid crosslinking rate upon ultraviolet irradiation, thus completing the present invention.

[0029] That is, the present invention is an organopolysiloxane composition, characterized in that it contains the following components (A) to (C). (A) Linear organopolysiloxane containing an alkenyl group bonded to a silicon atom (B) Organohydrogenpolysiloxane containing a hydrogen atom bonded to a silicon atom (C) Platinum group metal catalyst represented by the following formula (1) (In the formula, M represents a platinum group metal. R １ to R ８ each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.)

[0030] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0031] [Organopolysiloxane composition] The organopolysiloxane composition of the present invention contains the following components (A), (B), and (C), and may contain other components as necessary. Hereinafter, each component will be described in detail.

[0032] [Component (A)] Component (A) is a linear organopolysiloxane containing an alkenyl group bonded to a silicon atom. The molecular structure of component (A) is linear, with the main chain consisting of repeating units of diorganosiloxane. The position of the silicon atom to which the alkenyl group is bonded may be either at the molecular chain end (i.e., the triorganosiloxy group) or in the middle of the molecular chain (i.e., the bifunctional diorganosiloxane unit located at a non-terminal position of the molecular chain), or both, and it is preferably located only at the molecular chain end.

[0033] The alkenyl group is not particularly limited and may be linear, branched or cyclic, preferably having 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms, and even more preferably 2 to 6 carbon atoms. Specific examples of the alkenyl group include vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group and the like. Further, some or all of the hydrogen atoms of the alkenyl group may be substituted with a halogen atom such as F, Cl, Br or the like, or a cyano group or the like. Among these, a vinyl group is preferred.

[0034] The organic group other than the alkenyl group bonded to the silicon atom of component (A) is not particularly limited and may be linear, branched or cyclic, preferably having 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms.

[0035] Specific examples of the organic group other than the alkenyl group include linear or branched alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group and the like; cyclic alkyl groups such as cyclohexyl group; aryl groups such as phenyl group, naphthyl group, tolyl group, xylyl group, mesityl group and the like.

[0036] Further, some or all of the hydrogen atoms of the above organic group may be substituted with a halogen atom such as F, Cl, Br or the like, or a cyano group or the like. Specific examples of such a group include halogen-substituted alkyl groups such as chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group and the like, and halogen-substituted aryl groups such as chlorophenyl group.

[0037] Among these, as the organic group other than the alkenyl group, a methyl group or a phenyl group is preferred.

[0038] The number average degree of polymerization of component (A) is preferably 5 to 1500, more preferably 5 to 1200. If the number average molecular weight is 5 or more, the mechanical properties of the resulting organopolysiloxane cured product are improved, and if the number average degree of polymerization is 1500 or less, the viscosity is good for workability.

[0039] In this specification, the number-average degree of polymerization is determined from the number-average molecular weight obtained by GPC (gel permeation chromatography) analysis using toluene as the developing solvent, measured under the following conditions, and converted to a polystyrene equivalent.

[0040] [Measurement Conditions] Developing solvent: Toluene Flow rate: 0.35 mL / min Detector: Differential refractive index detector (RI) Column: TSK Guardcolumn SuperH-L TSKgel SuperH4000 (6.0 mm I.D. × 15 cm × 1) TSKgel SuperH3000 (6.0 mm I.D. × 15 cm × 1) TSKgel SuperH2000 (6.0 mm I.D. × 15 cm × 2) (All manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 10 μL (0.5 mass% toluene solution)

[0041] Furthermore, component (A) is preferably liquid at 25°C, and its viscosity at 25°C is preferably 10 to 100,000 mPa·s. If the viscosity is 10 mPa·s or higher, the mechanical properties of the resulting organopolysiloxane cured product are improved, and if the viscosity is 100,000 mPa·s or lower, the workability is good.

[0042] In this specification, the viscosity at 25°C is the value measured by a rotational viscometer using the method described in JIS K 7117-1:1999.

[0043] (A) Specific examples of component (A) include, but are not limited to, organopolysiloxanes represented by formulas (2) to (5) below. Me represents a methyl group, Ph represents a phenyl group, and Vi represents a vinyl group (the same applies below).

[0044] (A) The organopolysiloxane component may be used alone or in combination of two or more types.

[0045] [Component (B)] Component (B) is an organohydrogenpolysiloxane containing hydrogen atoms (Si-H groups) bonded to silicon atoms. The molecular structure of component (B) may be linear, cyclic, branched, or three-dimensional network, and the position of the hydrogen atoms bonded to the silicon atoms may be at the end of the molecular chain, in the middle of the molecular chain, or both.

[0046] (B) In component (B), the number of Si-H groups contained in one molecule is preferably 2 to 100, and more preferably 2 to 30. Within this range, the curability and the mechanical properties of the resulting organopolysiloxane cured product are improved.

[0047] The organic groups other than the hydrogen atoms bonded to the silicon atoms in component (B) above are not particularly limited and may be linear, branched, or cyclic, with a preferred number of carbon atoms of 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5.

[0048] Specific examples of organic groups include linear or branched alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, n-pentyl, n-hexyl, and n-heptyl groups; cyclic alkyl groups such as cyclohexyl groups; aryl groups such as phenyl, naphthyl, tolyl, xylyl, and mesityl groups; and trialkoxysilyl alkyl groups such as 2-(trimethoxysilyl)ethyl, 2-(triexxisilyl)ethyl, 3-(trimethoxysilyl)propyl, and 3-(triethoxysilyl)propyl groups.

[0049] Furthermore, some or all of the hydrogen atoms of the above organic group may be substituted with halogen atoms such as F, Cl, Br, or cyano groups. Specific examples of such groups include halogen-substituted alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl, and halogen-substituted aryl groups such as chlorophenyl.

[0050] Among these, methyl, phenyl, and 2-(trimethoxysilyl)ethyl groups are preferred as organic groups other than the hydrogen atom bonded to the silicon atom.

[0051] The number-average degree of polymerization of component (B) is preferably 5 to 500, and more preferably 5 to 300. If the number-average degree of polymerization is 5 or higher, the mechanical properties of the resulting organopolysiloxane cured product are improved, and if the number-average molecular weight is 500 or lower, the viscosity is such that it is easy to work with.

[0052] Furthermore, component (B) is preferably liquid at 25°C, and its viscosity at 25°C is preferably 0.5 to 10,000 mPa·s, more preferably 0.5 to 5,000 mPa·s, and even more preferably 1 to 2,000 mPa·s. If the viscosity is 0.5 mPa·s or higher, the mechanical properties of the resulting organopolysiloxane cured product are improved, and if the viscosity is 10,000 mPa·s or lower, the workability is good.

[0053] (B) Specific examples of component (B) include, but are not limited to, organohydrogenpolysiloxanes represented by the following formulas (6) to (10).

[0054] (B) The organohydrogenpolysiloxane may be used alone or in combination of two or more types.

[0055] The amount of component (B) blended is preferably such that the number of hydrogen atoms bonded to the silicon atoms in component (B) is 0.2 to 10 per alkenyl group in component (A), more preferably 0.5 to 5, and even more preferably 0.8 to 3. If the number is 0.2 or more, the curability of the organopolysiloxane composition is improved, and if it is 10 or less, the heat resistance of the resulting organopolysiloxane cured product is good.

[0056] Furthermore, in the organopolysiloxane composition of the present invention, if a component other than component (A) contains a component having an alkenyl group bonded to a silicon atom, and / or if a component other than component (B) contains a hydrogen atom bonded to a silicon atom, it is preferable to adjust the amount of each component so that the total number of hydrogen atoms bonded to silicon atoms in the composition is 0.2 to 10 per alkenyl group bonded to silicon atoms in the composition.

[0057] [(C) component] The (C) component is a platinum group metal catalyst and has a function of promoting the hydrosilylation reaction between the alkenyl group in the above-mentioned (A) component and the hydrogen bonded to the silicon atom in the (B) component. This platinum group metal catalyst is inactive in a shielded state, but changes to an active platinum catalyst at room temperature by irradiating light with a wavelength of 300 to 450 nm, thereby promoting the hydrosilylation reaction.

[0058] The platinum group metal catalyst of the (C) component is represented by the following formula (1). (In the formula, M represents a platinum group metal. R １ ~R ８ each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.)

[0059] In the above formula (1), M represents a platinum group metal. The platinum group metal may be any one having a function of promoting the hydrosilylation reaction, and examples thereof include ruthenium, palladium, osmium, iridium, and platinum. Ruthenium, palladium, and platinum are preferable, and platinum is more preferable.

[0060] R １ ~R ８ each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.

[0061] The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms. Specific examples of the alkyl group include linear or branched alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, n-pentyl group, n-hexyl group, and n-heptyl group; and cyclic alkyl groups such as cyclohexyl group. Further, part or all of the hydrogen atoms of the alkyl group may be substituted with halogen atoms such as F, Cl, and Br, or cyano groups, and specific examples of such groups include halogen-substituted alkyl groups such as chloromethyl group, 3-chloropropyl group, and 3,3,3-trifluoropropyl group.

[0062] The aryl group is preferably one having 6 to 20 carbon atoms, and more preferably one having 6 to 10 carbon atoms. Specific examples of aryl groups include phenyl, naphthyl, tolyl, xylyl, and mesityl groups. Furthermore, some or all of the hydrogen atoms of the aryl group may be substituted with halogen atoms such as F, Cl, and Br, or cyano groups. Specific examples of such groups include chlorophenyl.

[0063] Among these, R １ ~R ８ The preferred groups are methyl, ethyl, and phenyl groups, with methyl and ethyl groups being more preferred.

[0064] (C) component is the R in formula (1) above. １ ~R ８ However, each is independently a methyl group or an ethyl group, and it is preferable that M is platinum.

[0065] The amount of component (C) is not limited as long as it promotes the curing (hydrosilylation reaction) of the organopolysiloxane composition, but it is preferably in the range of 0.01 to 100 ppm, more preferably in the range of 0.05 to 80 ppm, and even more preferably in the range of 0.1 to 50 ppm, relative to component (A) in terms of the mass of platinum group metals. If it is 0.01 ppm or more, the resulting organopolysiloxane cured product will have sufficient curability, and if it is 100 ppm or less, the pot life of the organopolysiloxane composition will be improved.

[0066] Specific examples of platinum group metal catalysts for component (C) include, but are not limited to, those represented by the following formulas (11) to (13). (In the formula, Et represents an ethyl group.)

[0067] The platinum group metal catalyst of component (C) may be used alone or in combination of two or more types.

[0068] [Component (D)] The organopolysiloxane composition of the present invention may optionally contain an adhesive aid as component (D) to provide adhesion to a substrate such as a polarizing plate, glass, polycarbonate resin, or acrylic resin.

[0069] (D) Specific examples of adhesive aids containing siloxane bonds among the components include vinyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-1003), γ-(glycidyloxypropyl)trimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403), γ-(methacryloxypropyl)trimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503), their hydrolysates, and compounds represented by the following structural formulas.

[0070]

[0071] Furthermore, specific examples of adhesive aids that do not contain siloxane bonds include allyl glycidyl ether, vinylcyclohexene monooxide, 2-allyl malonate diethyl, diallyl bisphenol ether, allyl benzoate, diallyl phthalate, tetraallyl pyromellitic acid ester (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., TRIAM805), and triallyl isocyanurate. Note that component (D) may be used alone or in combination of two or more types.

[0072] When component (D) is used, the amount added is preferably 0.05 to 10 parts by mass, and more preferably 0.05 to 5 parts by mass, per 100 parts by mass of component (A). If the amount of component (D) is within the above range, appropriate adhesiveness can be provided.

[0073] [Component (E)] The organopolysiloxane composition of the present invention may optionally contain a reaction control agent (E) to control the reactivity of the hydrosilylation reaction catalyst so as not to cause thickening or gelation before light irradiation, such as when preparing the composition or when coating the composition onto a substrate.

[0074] Specific examples of reaction control agents include 3-methyl-1-butyne-3-ol, 3-methyl-1-pentin-3-ol, 3,5-dimethyl-1-hexyne-3-ol, 1-ethynylcyclohexanol, ethinylmethyldecylcarbinol, 3-methyl-3-trimethylsiloxy-1-butyne, 3-methyl-3-trimethylsiloxy-1-pentyne, 3,5-dimethyl-3-trimethylsiloxy-1-hexyne, 1-ethynyl-1-trimethylsiloxycyclohexane, bis(2,2-dimethyl-3-butinoxy)dimethylsilane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,1,3,3-tetramethyl-1,3-divinyldisiloxane, etc. These may be used individually or in combination of two or more.

[0075] Among these, 1-ethynylcyclohexanol, ethinylmethyldecylcarbinol, 3-methyl-1-buty-3-ol, and bis(2,2-dimethyl-3-butinoxy)dimethylsilane are preferred.

[0076] The amount of component (E) is preferably 0.01 to 2.0 parts by mass, and more preferably 0.01 to 0.1 parts by mass, per 100 parts by mass of the total of component (A). Within this range, the effect of reaction control is sufficiently exhibited.

[0077] [Other Components] In addition to the components (A) to (E) above, the organopolysiloxane composition of the present invention may also contain other components as exemplified below, depending on the purpose of the present invention.

[0078] Other components include, for example, thixotropic agents such as fumed silica; reinforcing agents such as crystalline silica; antioxidants; light stabilizers; heat resistance improvers such as metal oxides and metal hydroxides; colorants such as titanium dioxide; thermal conductivity-imparting fillers such as alumina and crystalline silica; viscosity modifiers such as non-reactive organopolysiloxane oils that do not have reactive functional groups; conductivity-imparting agents such as metal powders such as silver and gold; and organic solvents such as toluene, xylene, hexane, and ethyl acetate.

[0079] The organopolysiloxane composition of the present invention can be prepared by mixing the above components (A) to (C), components (D) and (E) as needed, and other components by known methods.

[0080] The organopolysiloxane composition of the present invention preferably has a viscosity increase rate of 10% or less after 4 weeks in a light-shielded environment at 40°C, and more preferably 5% or less. The organopolysiloxane composition having a viscosity increase rate within the above range will fully satisfy the required pot life.

[0081] The viscosity increase rate is calculated by measuring the viscosity of the organopolysiloxane composition immediately after preparation (initial viscosity) and the viscosity after storage at 40°C for 4 weeks under light shielding, and formulating the following: [{(viscosity after 4 weeks at 40°C) - (initial viscosity)} / (initial viscosity)] × 100 = (viscosity increase rate, %). In this invention, the above viscosity is measured using a rheometer (manufactured by Thermo Fisher Scientific Co., Ltd.) at a constant shear rate (10 s). －１ This value represents the rotational viscosity (mPa·s) measured at 25°C.

[0082] [Organopolysiloxane Cured Product] The organopolysiloxane composition of the present invention can be cured by irradiation with light such as ultraviolet light. Examples of ultraviolet light sources include UV LED lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, carbon arc lamps, and xenon lamps. A useful ultraviolet wavelength range is 300 to 450 nm, more preferably 340 to 420 nm. The amount of ultraviolet irradiation (cumulative light dose) is not particularly limited as long as it is sufficient for curing, but preferably 100 to 30,000 mJ / cm². ２ More preferably, 1000 to 10000 mJ / cm² ２ That is the case.

[0083] Furthermore, irradiating the material with light such as ultraviolet light and then heating it at a low temperature of 100°C or below is also an effective way to accelerate curing.

[0084] [Laminate] The laminate of the present invention is formed by laminating a substrate and the organopolysiloxane cured product of the present invention.

[0085] Examples of the above-mentioned substrates include polarizing materials and composite materials, metal components, plastic components, ceramic components, etc. They are particularly useful for applications in fields such as casing, coating, casting, bonding, and sealing of components in electrical, electronic, and optical applications, and are especially useful for polarizing plates and polarizing films.

[0086] Furthermore, the organopolysiloxane composition of the present invention can also be used on substrates that have been activated by well-known pretreatment processes such as primer treatment, plasma treatment, and excimer phototreatment.

[0087] The laminate of the present invention can be obtained, for example, by applying the organopolysiloxane composition of the present invention to the surface of a substrate and curing the applied organopolysiloxane composition by irradiating it with ultraviolet light.

[0088] The present invention will be specifically described below using examples and comparative examples, but the present invention is not limited to these.

[0089] [Examples 1-4, Comparative Examples 1-5] The following components were mixed in the amounts (parts by mass) shown in Table 1 to prepare organopolysiloxane compositions.

[0090] In the examples below, Me represents a methyl group, Ph represents a phenyl group, and Vi represents a vinyl group. Viscosity is measured at 25°C using a rotational viscometer according to the method described in JIS K 7117-1:1999.

[0091] (A) Component: (A-1) Linear organopolysiloxane represented by the following average formula (2) (A-2) Linear organopolysiloxane represented by the following formula (3) (A-3) Linear organopolysiloxane represented by the following formula (4) (A-4) Linear organopolysiloxane represented by the following formula (5)

[0092] (B) Component: (B-1) Organohydrogenpolysiloxane represented by the following formula (7) (B-2) Organohydrogenpolysiloxane represented by the following average formula (8) (B-3) Organohydrogenpolysiloxane represented by the following formula (9) (B-4) Organohydrogenpolysiloxane represented by the following formula (10)

[0093] (C) Components: (C-1) Dimethylvinylsiloxy group-sealed polysiloxane solution of trimethyl(pentamethylcyclopentadienyl)platinum(IV) (viscosity 600 mPa·s, 0.59 mass%) (C-2) Toluene solution of trimethyl(pentamethylcyclopentadienyl)platinum(IV) (viscosity 0.60 mPa·s, 0.59 mass%) (C-3) Dimethylvinylsiloxy group-sealed polysiloxane solution of trimethyl(methylcyclopentadienyl)platinum(IV) (viscosity 600 mPa·s, 0.50 mass%) (C-4) Toluene solution of bis(acetylacetonate)platinum(II) (viscosity 0.60 mPa·s, 0.62 mass%) (C-5) Trimethyl(cyclopentadienyl)platinum(IV) in a dimethylvinylsiloxy group-sealed polysiloxane solution (viscosity 600 mPa·s, 0.48% by mass) (C-6) Trimethyl(ethylcyclopentadienyl)platinum(IV) in a toluene solution (viscosity 0.6 mPa·s, 0.52% by mass)

[0094] (D) Components: (D-1) 7-Octenyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-1083) (D-2) Compound represented by the following formula (14) (D-3) Compound represented by the following formula (15)

[0095] (E) Components: (E-1) Dimethylvinylsiloxy group-sealed polysiloxane solution of ethinylmethyldecylcarbinol (viscosity 600 mPa·s, 0.39% by mass) (E-2) Dimethylvinylsiloxy group-sealed polysiloxane solution of bis(2,2-dimethyl-3-butinoxy)dimethylsilane (viscosity 600 mPa·s, 1.0% by mass)

[0096] Other ingredients: Silica (manufactured by Nippon Aerosil Co., Ltd., Aerosil NSX-200, fumed silica with an average primary particle size of 8 nm)

[0097]

[0098] The organopolysiloxane compositions prepared in Examples 1-3 and Comparative Examples 1-5 were evaluated for gelation time, viscosity, and viscosity increase rate using the following method. The results are shown in Table 2.

[0099] [Gelation Time] The gelation time was measured using a viscoelasticity measuring device ARES-G2 (manufactured by T.A. Instruments Japan Co., Ltd.) equipped with a UV curing accessory.

[0100] One ml of each prepared photocurable organopolysiloxane composition was coated onto a stainless steel plate, and a UV-LED lamp with a peak wavelength of 365 nm (Panasonic Corporation, ANOJ6186) was used at 100 mW / cm². ２ The light was 3,000 mJ / cm². ２ Each composition was irradiated under a 25°C environment to achieve the desired result, and its viscoelasticity was measured. The time (in minutes) required from the start of UV irradiation until tanδ = 1 was defined as the gelation time.

[0101] [Viscosity] Using a HAAKE MARS rheometer (manufactured by Thermo Fisher Scientific Co., Ltd.), a constant shear rate (10 s) was measured. －１ The rotational viscosity (mPa·s) was measured at 25°C.

[0102] [Viscosity Increase Rate] The viscosity of the organopolysiloxane composition immediately after preparation (initial viscosity) and the viscosity after storage at 40°C for 4 weeks under light shielding were measured, and the viscosity increase rate was calculated as follows: [{(Viscosity after 4 weeks at 40°C) - (initial viscosity)} / (initial viscosity)] × 100 = (Viscosity increase rate, %).

[0103]

[0104] As shown in Table 2, in Examples 1 to 3 using the organopolysiloxane composition of the present invention, crosslinking proceeded rapidly upon UV irradiation, and even after 4 weeks at 40°C, the increase in viscosity was minimal, demonstrating excellent long-term pot life.

[0105] On the other hand, in Comparative Examples 1 to 4, in which component (C) was changed to trimethyl(methylcyclopentadienyl) platinum complex, bis(acetylacetonate) platinum complex, trimethyl(cyclopentadienyl) platinum complex, and trimethyl(ethylcyclopentadienyl) platinum complex, the gelation time was short and the curing performance was excellent, but the viscosity increase rate was large and the pot life was significantly inferior.

[0106] Furthermore, in Comparative Example 5, where a large amount of reaction control agent was added as component (E), although the viscosity increase rate was kept low at 4.0%, it was found that the gelation time was significantly delayed.

[0107] This specification includes the following embodiments: [1] An organopolysiloxane composition characterized by comprising the following components (A) to (C): (A) A linear organopolysiloxane containing an alkenyl group bonded to a silicon atom (B) An organohydrogenpolysiloxane containing a hydrogen atom bonded to a silicon atom (C) A platinum group metal catalyst represented by the following formula (1) (In the formula, M represents a platinum group metal. R １ ~R ８ (Each of these independently represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.) [2] The organopolysiloxane composition according to [1], characterized in that the number of hydrogen atoms bonded to the silicon atom in component (B) is 0.2 to 10 per alkenyl group in component (A). [3] The R in component (C) １ ~R ８The organopolysiloxane composition according to [1] or [2], characterized in that each is independently a methyl group or an ethyl group, and the M is platinum. [4] The organopolysiloxane composition according to any one of [1] to [3], characterized in that the platinum group metal concentration derived from component (C) is 0.01 to 100 ppm relative to component (A). [5] The organopolysiloxane composition according to any one of [1] to [4], characterized in that the viscosity increase rate after 4 weeks in a light-shielded environment at 40°C is 10% or less. [6] An organopolysiloxane cured product, characterized in that the organopolysiloxane composition according to any one of [1] to [5] has been cured. [7] A laminate, characterized in that a substrate and the organopolysiloxane cured product according to [6] are laminated together.

[0108] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention.

Claims

1. An organopolysiloxane composition characterized by containing the following components (A) to (C): (A) A linear organopolysiloxane containing alkenyl groups bonded to silicon atoms (B) An organohydrogenpolysiloxane containing hydrogen atoms bonded to silicon atoms (C) A platinum group metal catalyst represented by the following formula (1) (In the formula, M represents a platinum group metal. R １ ~R ８ Each of these independently represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

2. The organopolysiloxane composition according to claim 1, characterized in that the number of hydrogen atoms bonded to the silicon atom in component (B) is 0.2 to 10 per alkenyl group in component (A).

3. The R in component (C) １ ~R ８ The organopolysiloxane composition according to claim 1, characterized in that each of the groups is independently a methyl group or an ethyl group, and the M is platinum.

4. The organopolysiloxane composition according to claim 1, characterized in that the platinum group metal concentration derived from component (C) is 0.01 to 100 ppm relative to component (A).

5. The organopolysiloxane composition according to claim 1, characterized in that the viscosity increase rate after 4 weeks in a light-shielded environment at 40°C is 10% or less.

6. A cured organopolysiloxane product characterized by being a cured organopolysiloxane composition according to any one of claims 1 to 5.

7. A laminate characterized by being formed by laminating a substrate and the organopolysiloxane cured product described in claim 6.

Images