Organopolysiloxane compositions, cured products, and laminates
The composition of linear organopolysiloxane, organohydrogenpolysiloxane, and platinum catalyst addresses the trade-off of pot life and crosslinking rate, enabling storage at normal temperatures and rapid UV-induced crosslinking for optical device applications.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-09-18
- Publication Date
- 2026-03-31
AI Technical Summary
Existing ultraviolet-curable organopolysiloxane compositions face a trade-off between pot life and crosslinking rate, requiring storage in dark and cool places or complex mixing methods, which are impractical and can lead to deviations in physical properties.
A composition comprising linear organopolysiloxane with alkenyl groups, organohydrogenpolysiloxane with Si-H groups, and a platinum group metal catalyst that remains inactive in the dark but activates upon UV irradiation, allowing storage at normal temperatures and rapid crosslinking.
The composition achieves long pot life at room temperature under light-shielding conditions and rapid crosslinking upon UV irradiation, with minimal viscosity increase, suitable for bonding and sealing optical devices.
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Abstract
Description
[Technical Field]
[0001] The present invention relates to organopolysiloxane compositions, cured products thereof, and laminates. [Background technology]
[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 mentioned 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 UV irradiation. While the use of large amounts of reaction control agents, or 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. [Prior art documents] [Patent Documents]
[0009] [Patent Document 1] Japanese Patent Publication No. 2015-110752 [Patent Document 2] Special Publication No. 2020-522582 [Patent Document 3] Japanese Patent Publication No. 2001-089491 [Patent Document 4] Japanese Patent Publication No. 2020-158548 [Patent Document 5] Japanese Patent Publication No. 2024-040726 [Patent Document 6] Japanese Patent Publication No. 2016-150991 [Overview of the project] [Problems that the invention aims to solve]
[0010] In the prior art, there has been a problem that in an ultraviolet-curable organopolysiloxane composition, the pot life and the crosslinking rate are in a trade-off relationship and it is difficult to achieve both simultaneously.
[0011] The present invention has been made to solve the above problems, and an object thereof is to provide an organopolysiloxane composition, a cured product, and a laminate that can be stored for a long period under shading at normal temperature (approximately 25 to 40°C) and can be rapidly crosslinked by ultraviolet irradiation.
Means for Solving the Problems
[0012] In order to solve the above problems, the present invention provides an organopolysiloxane composition 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)
Chemical formula
[0013] The above organopolysiloxane composition can be stored for a long period in the dark at about 25 to 40°C and has rapid crosslinkability by ultraviolet irradiation. Further, an organopolysiloxane cured product and a laminate obtained by curing such an organopolysiloxane composition are suitable for adhesion, sealing, etc. of optical devices such as image display devices.
[0014] In this case, in the organopolysiloxane composition of the present invention, the number of hydrogen atoms bonded to the silicon atom in the component (B) is preferably 0.2 to 10 with respect to one alkenyl group in the 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. [Effects of the Invention]
[0026] As described above, the organopolysiloxane composition of the present invention can be stored for a long time at room temperature (generally around 25-40°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. [Modes for carrying out the invention]
[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 diligent research into the above-mentioned problems, the inventors have found that an organopolysiloxane composition containing the following components (A), (B), and (C) can achieve both a long pot life, i.e., long-term storage at room temperature under light shielding, and a rapid crosslinking rate upon ultraviolet irradiation, thereby completing the present invention.
[0029] In other words, the present invention is an organopolysiloxane composition characterized by containing the following components (A) to (C). (A) Linear organopolysiloxane containing alkenyl groups bonded to silicon atoms (B) Organohydrogenpolysiloxane containing hydrogen atoms bonded to silicon atoms (C) Platinum group metal catalyst represented by the following formula (1) [ka] (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.
[0030] The present invention will be described in detail below, but the present invention is not limited to these descriptions.
[0031] [Organopolysiloxane composition] The organopolysiloxane composition of the present invention comprises the following components (A), (B), and (C), and may contain other components as needed. Each component will be described in detail below.
[0032] [(A) component] 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 diorganosiloxane units. The position of the silicon atom to which the alkenyl group is bonded may be either at the end of the molecular chain (i.e., the triorganosiloxy group) or in the middle of the molecular chain (i.e., a bifunctional diorganosiloxane unit located off-terminal), or both, but it is preferable that it is located only at the end of the molecular chain.
[0033] The above 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 alkenyl groups include vinyl, allyl, butenyl, pentenyl, and hexenyl groups. Furthermore, some or all of the hydrogen atoms of the alkenyl group may be substituted with halogen atoms such as F, Cl, and Br, or cyano groups. Among these, the 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, with a preferred number of carbon atoms of 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5.
[0035] Specific examples of organic groups other than alkenyl 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; and aryl groups such as phenyl, naphthyl, tolyl, xylyl, and mesityl groups.
[0036] 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.
[0037] Among these, methyl or phenyl groups are preferred as organic groups other than alkenyl groups.
[0038] The number-average degree of polymerization of component (A) is preferably 5 to 1500, and more preferably 5 to 1200. If the number-average molecular weight is 5 or higher, the mechanical properties of the resulting organopolysiloxane cured product are improved, and if the number-average degree of polymerization is 1500 or lower, a viscosity with good workability is obtained.
[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: 0.35mL / min Detector: Differential refractive index detector (RI) Column: TSK Guardcolumn SuperH-L TSKgel SuperH4000(6.0mmI.D.×15cm×1) TSKgel SuperH3000(6.0mmI.D.×15cm×1) TSKgel SuperH2000(6.0mmI.D.×15cm×2) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 10 μL (0.5% by 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 using a rotational viscometer according to 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. Note that Me represents a methyl group, Ph represents a phenyl group, and Vi represents a vinyl group (the same applies below). [ka]
[0044] (A) The organopolysiloxane may be used alone or in combination of two or more types.
[0045] [(B) Component] 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) The number of Si-H groups contained in one molecule of component 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). [ka]
[0054] (B) The organohydrogenpolysiloxane may be used alone or in combination of two or more types.
[0055] The amount of component (B) is preferably such that the number of hydrogen atoms bonded to 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 amount 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] In the organopolysiloxane composition of the present invention, when a component having an alkenyl group bonded to a silicon atom is contained in addition to the component (A), and / or when a component having a hydrogen atom bonded to a silicon atom is contained in addition to the component (B), it is preferable to adjust the blending amounts of the respective components so that the hydrogen atoms bonded to the silicon atoms in the whole composition are 0.2 to 10 with respect to one alkenyl group bonded to the silicon atoms in the whole composition.
[0057] [Component (C)] Component (C) is a platinum group metal catalyst and has a function of promoting the hydrosilylation reaction between the alkenyl group in the above-mentioned component (A) and the hydrogen bonded to the silicon atom in the component (B). 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, and promotes the hydrosilylation reaction.
[0058] The platinum group metal catalyst of component (C) is represented by the following formula (1). [Chemical formula] (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. Any platinum group metal having a function of promoting the hydrosilylation reaction may be used, and examples 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 is preferably one having 1 to 20 carbon atoms, more preferably one having 1 to 10 carbon atoms, and even more preferably one having 1 to 5 carbon atoms. Specific examples of alkyl 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; and cyclic alkyl groups such as cyclohexyl groups. Furthermore, some 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. Specific examples of such groups include halogen-substituted alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl groups.
[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). [ka] (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] [(D) component] The organopolysiloxane composition of the present invention may optionally contain an adhesive aid as component (D) to impart 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] [ka]
[0071] Furthermore, specific examples of adhesive aids that do not contain siloxane bonds include allyl glycidyl ether, vinylcyclohexene monooxide, diethyl 2-allylmalonate, diallyl bisphenol ether, allyl benzoate, diallyl phthalate, tetraallyl pyromellitic acid (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 using component (D), 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] [(E) component] The organopolysiloxane composition of the present invention may optionally contain (E) a reaction control agent 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 ingredients] 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 control 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 was determined 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. [{(Viscosity after 4 weeks at 40°C) - (Initial viscosity)} / (Initial viscosity)] × 100 = (Viscosity increase rate, %) This value was calculated as follows. Furthermore, in this invention, the viscosity is measured using a rheometer (manufactured by Thermo Fisher Scientific Co., Ltd.) at a constant shear rate (10s). -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 is preferably 100 to 30000 mJ / cm². 2 And 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] [Laminated structure] The laminate of the present invention is formed by laminating a substrate with 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. [Examples]
[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 values were measured at 25°C using a rotational viscometer according to the method described in JIS K 7117-1:1999.
[0091] (A) Ingredients: (A-1) Linear organopolysiloxane represented by the following average formula (2) [ka] (A-2) Linear organopolysiloxane represented by the following formula (3) [ka] (A-3) Linear organopolysiloxane represented by the following formula (4) [ka] (A-4) Linear organopolysiloxane represented by the following formula (5) [ka]
[0092] (B) Ingredients: (B-1) Organohydrogenpolysiloxane represented by the following formula (7) [ka] (B-2) Organohydrogenpolysiloxane represented by the following average formula (8) [ka] (B-3) Organohydrogenpolysiloxane represented by the following formula (9) [ka] (B-4) Organohydrogenpolysiloxane represented by the following formula (10) [ka]
[0093] (C) Ingredients: (C-1) Trimethyl(pentamethylcyclopentadienyl)platinum(IV) dimethylvinylsiloxy group-sealed polysiloxane solution (viscosity 600 mPa·s, 0.59% by mass) (C-2) Trimethyl(pentamethylcyclopentadienyl)platinum(IV) solution in toluene (viscosity 0.60 mPa·s, 0.59 mass%) (C-3) Trimethyl(methylcyclopentadienyl)platinum(IV) dimethylvinylsiloxy group-sealed polysiloxane solution (viscosity 600 mPa·s, 0.50% by mass) (C-4) Toluene solution of bis(acetylacetonate)platinum(II) (viscosity 0.60 mPa·s, 0.62 mass%) (C-5) Trimethyl(cyclopentadienyl)platinum(IV) dimethylvinylsiloxy group-sealed polysiloxane solution (viscosity 600 mPa·s, 0.48% by mass) (C-6) Trimethyl(ethylcyclopentadienyl)platinum(IV) solution in toluene (viscosity 0.6 mPa·s, 0.52% by mass)
[0094] (D) Ingredients: (D-1)7-Octenyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-1083) (D-2) Compound represented by the following formula (14) [ka] (D-3) Compound represented by the following formula (15) [ka]
[0095] (E) Ingredients: (E-1) Ethinylmethyldecylcarbinol dimethylvinylsiloxy group-sealed polysiloxane solution (viscosity 600 mPa·s, 0.39% by mass) (E-2) Bis(2,2-dimethyl-3-butinoxy)dimethylsilane solution of dimethylvinylsiloxy group-sealed polysiloxane (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] [Table 1]
[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 to expose the plate 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 (10s) was used. -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. [{(Viscosity after 4 weeks at 40°C) - (Initial viscosity)} / (Initial viscosity)] × 100 = (Viscosity increase rate, %) That's what I decided.
[0103] [Table 2]
[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 viscosity increase 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 containing the following components (A) to (C). (A) Linear organopolysiloxane containing alkenyl groups bonded to silicon atoms (B) Organohydrogenpolysiloxane containing hydrogen atoms bonded to silicon atoms (C) Platinum group metal catalyst represented by the following formula (1) [ka] (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 8 The 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] An 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. A cured organopolysiloxane product characterized by being a cured organopolysiloxane composition according to any one of items [6], [1] to [5]. [7] A laminate characterized by being formed by laminating a substrate and the organopolysiloxane cured product described in [6].
[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) Linear organopolysiloxane containing alkenyl groups bonded to silicon atoms (B) Organohydrogenpolysiloxane containing hydrogen atoms bonded to silicon atoms (C) Platinum group metal catalyst represented by the following formula (1) 【Chemistry 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 the (C) component 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 an organopolysiloxane cured product according to claim 6.
Citation Information
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