Epoxy group-containing cyclic organopolysiloxane, curable composition containing same, and cured product thereof

Abstract

To provide epoxy group-containing organopolysiloxane that yields a cured product having excellent crack resistance and flexibility.SOLUTION: The present invention provides epoxy group-containing cyclic organopolysiloxane, represented by a general formula (1). (R1 to R4 each represent a monovalent hydrocarbon group or the like; Z1 and Z2 each represent a monovalent hydrocarbon group, an epoxy group-containing monovalent organic group, or the like, where at least one of them is an epoxy group-containing monovalent organic group).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an epoxy group-containing cyclic organopolysiloxane, a curable composition containing the same, and a cured product thereof. More specifically, the present invention relates to an organopolysiloxane in which epoxy group-containing cyclic siloxane skeletons are linked by linking groups, a curable composition containing the same, and a cured product thereof. [Background technology]

[0002] Organopolysiloxanes having epoxy groups have superior heat yellowing resistance and low cure shrinkage compared to epoxy materials having a non-siloxane phenolic resin skeleton, and therefore encapsulants and lens molding materials using epoxy-functional polysiloxanes have been proposed for use in electronic materials (Patent Documents 1 and 2). Furthermore, it has been proposed that organopolysiloxanes having epoxy groups be used as paint binders, taking advantage of the heat resistance and weather resistance of the siloxane skeleton (Patent Documents 3 to 6).

[0003] On the other hand, conventional curable epoxy materials have the drawback of being prone to cracking in their cured products, and even organopolysiloxanes containing epoxy groups have not yet achieved sufficient improvement in properties. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-171021 [Patent Document 2] Japanese Patent Application Publication No. 2019-189874 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-112599 [Patent Document 4] Japanese Patent Application Publication No. 2019-143161 [Patent Document 5] Japanese Patent Application Publication No. 2019-108541 [Patent Document 6] Japanese Patent Application Laid-Open No. 2012-144678 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an epoxy group-containing organopolysiloxane that gives a cured product that has excellent crack resistance and flexibility, a curable composition containing the same, and a cured product thereof. [Means for solving the problem]

[0006] As a result of extensive research conducted by the present inventors in order to achieve the above object, they discovered that organopolysiloxanes having a main skeleton in which epoxy group-containing cyclic siloxanes are linked by linking groups improve the flexibility and crack resistance of cured products obtained by polymerization of the epoxy groups, and thus completed the present invention.

[0007] That is, the present invention is 1. An epoxy group-containing cyclic organopolysiloxane represented by the following general formula (1): [ka] (In the formula, R 1 , R 2 , R 3 and R 4 each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms which may be interrupted by an oxygen atom, Y represents a divalent hydrocarbon group; Z 1 and Z 2 each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms which may be interrupted by an oxygen atom, an epoxy group-containing monovalent organic group which may be interrupted by an oxygen atom, an alkoxysilylalkyl group, or a hydrogen atom, and at least one of them is an epoxy group-containing monovalent organic group which may be interrupted by an oxygen atom; n1 and n2 each independently represent an integer of 1 to 5 and satisfy the relationship n1+n2=3 to 6; n3 and n4 each independently represent an integer of 1 to 5 and satisfy the relationship n3+n4=3 to 6; m represents an integer of 1 to 11. 2. The above R 1 , R 2 , R 3 and R 4 is a methyl group, 3. Said Z 1 and Z 2 is at least one selected from a 3-glycidyloxypropyl group and a 2-(3,4-epoxycyclohexyl)ethyl group; 4. The epoxy group-containing cyclic organopolysiloxane of 1, wherein Y is a divalent saturated hydrocarbon group having a polycyclic structure. 5. The epoxy group-containing cyclic organopolysiloxane of 4, wherein Y is at least one divalent saturated hydrocarbon group selected from the group consisting of the following formulas (2a) and (2b): [ka] (In the formula, an asterisk (*) indicates the bonding site to the silicon atom, and the configuration at each asymmetric carbon may be either cis (exo) or trans (endo).) 6. The epoxy group-containing cyclic organopolysiloxane of 1, wherein n1 and n4 are 3, and n2 and n3 are 1. 7. The epoxy group-containing cyclic organopolysiloxane of 1, wherein the functional group equivalent weight of the epoxy group is 200 to 400 g / mol. 8. (A) 100 parts by mass of any one of the epoxy group-containing cyclic organopolysiloxanes 1 to 7, and (B) Curing agent: 0.01 to 5 parts by mass a curable composition comprising: 9. The curable composition of 8, containing 1 to 200 parts by mass of (C) an epoxy group-containing compound other than (A); 10. The curable composition of 9, wherein the curing agent is a photoacid generator. 11. A cured product obtained by curing the curable composition of 9. to provide. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an epoxy group-containing organopolysiloxane that gives a cured product that is crack-resistant and flexible, and a curable composition containing the same. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be specifically described below. [1] Epoxy group-containing organopolysiloxane The epoxy group-containing cyclic organopolysiloxane according to the present invention is represented by the following general formula (1).

[0010] [ka]

[0011] In formula (1), R 1 , R 2 , R 3 and R 4 each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms which may be interrupted by an oxygen atom. The monovalent hydrocarbon group may be linear, branched, or cyclic, and specific examples thereof include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, cyclohexyl, n-octyl, 2-ethylhexyl, and n-decyl; alkenyl groups such as vinyl, allyl (2-propenyl), 1-propenyl, isopropenyl, and butenyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; and aralkyl groups such as benzyl, phenylethyl, and phenylpropyl.

[0012] Among these, alkyl groups having 1 to 20 carbon atoms and aryl groups having 6 to 12 carbon atoms are preferred, alkyl groups having 1 to 10 carbon atoms are more preferred, alkyl groups having 1 to 5 carbon atoms are even more preferred, and methyl groups are even more preferred. The monovalent hydrocarbon group may have an oxygen atom present within the molecular chain or at the Si terminal, and may be, for example, an alkoxy group having 1 to 20 carbon atoms.

[0013] In formula (1), Y represents a divalent hydrocarbon group. This group is not particularly limited, but is preferably a divalent saturated hydrocarbon group having a polycyclic structure, more preferably groups represented by the following formulae (2a), (2b), and (10a) to (10c), and even more preferably groups represented by formulae (2a) and (2b). The left-right direction of the asymmetric divalent hydrocarbon group represented by the formula below is not limited to the following, and the hydrocarbon group may have a structure obtained by rotating each of the formulas below by 180° on the paper. Furthermore, the hydrocarbon group represented by the formula below may be a combination of each structure.

[0014] [ka] (In the formula, an asterisk (*) indicates the bonding site to the silicon atom, and the configuration at each asymmetric carbon may be either cis (exo) or trans (endo).)

[0015] In formula (1), Z 1 and Z 2 each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms which may be interrupted by an oxygen atom, an epoxy group-containing monovalent organic group which may be interrupted by an oxygen atom, an alkoxysilylalkyl group, or a hydrogen atom, and at least one of them is an epoxy group-containing monovalent organic group which may be interrupted by an oxygen atom. Z 1 and Z 2 The monovalent hydrocarbon group of R 1 ~R 4 Examples of the groups include the same as those exemplified in the above. The epoxy group-containing monovalent organic group is not particularly limited as long as it contains an epoxy group, but a 3-glycidyloxypropyl group and a 2-(3,4-epoxycyclohexyl)ethyl group are particularly preferred. Examples of the alkoxysilylalkyl group include 2-(trimethoxysilyl)ethyl, 2-(methyldimethoxysilyl)ethyl, 2-(dimethylmethoxysilyl)ethyl, 2-(triethoxysilyl)ethyl, 2-(methyldiethoxysilyl)ethyl, 2-(dimethylethoxysilyl)ethyl, 6-(trimethoxysilyl)hexyl, and 8-(trimethoxysilyl)octyl groups.

[0016] In formula (1), n1 and n2 each independently represent an integer of 1 to 5 and satisfy the condition n1+n2=3 to 6, and n3 and n4 each independently represent an integer of 1 to 5 and satisfy the condition n3+n4=3 to 6. It is particularly preferred that n1 and n4 are 3, and n2 and n3 are 1. Furthermore, m represents an integer of 1 to 11.

[0017] As the epoxy group-containing cyclic organopolysiloxane represented by the above formula (1), the compounds represented by the following formulas (4) to (7) are preferred because the raw materials are easily available and they have excellent compatibility with general-purpose epoxy binders, but the invention is not limited to these. In the following, Me means a methyl group.

[0018] [ka]

[0019] [ka] (In the formula, m1 represents an integer of 2 to 11.)

[0020] [ka]

[0021] [ka] (In the formula, m2 represents an integer of 2 to 11.)

[0022] The epoxy group-containing cyclic organopolysiloxane compound of the present invention can be obtained, for example, by addition reaction of a cyclic organohydrogenpolysiloxane represented by the following formula (3) with a compound having one addition-reactive carbon-carbon double bond per molecule and having an epoxy group.

[0023] [ka]

[0024] In each of formula (3), R 1 ~R 4 , Y, n1 to n4, and m have the same meanings as above, and Z 11 , Z 12 each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms which may be interrupted by an oxygen atom, or a hydrogen atom, and at least one of these is a hydrogen atom. Z 11 and Z 12 The monovalent hydrocarbon group of the above R 1 ~R 4 Examples of the groups include the same as those exemplified in the above.

[0025] Specific examples of the compound represented by the above formula (3) include, but are not limited to, those represented by the following formula (8).

[0026] [ka] (In the formula, m3 represents an integer of 1 to 11.)

[0027] The compound having one addition-reactive carbon-carbon double bond in one molecule and having an epoxy group is not particularly limited, but allyl glycidyl ether, hexenyl glycidyl ether, octenyl glycidyl ether, vinylcyclohexene oxide, and the like are preferred, and from the viewpoint of marketability, allyl glycidyl ether and vinylcyclohexene oxide are more preferred. From the viewpoint of the thermal stability and productivity of the resulting epoxy group-containing cyclic organopolysiloxane, the amount of the compound used is preferably 1 to 10 moles, and more preferably 1.5 to 5 moles, per mole of hydrogen atoms bonded to silicon atoms (Si-H groups) in the compound represented by formula (3) above.

[0028] The catalyst used in the addition reaction may be a known catalyst typically used in hydrosilylation addition reactions, and examples thereof include platinum metal-supported carbon powder, platinic chloride, chloroplatinic acid, reaction products of chloroplatinic acid with monohydric alcohols, complexes of chloroplatinic acid with olefins; and platinum group metal catalysts such as palladium-based catalysts and rhodium-based catalysts. Considering the prevention of side reactions and the coloring of the product, the amount of catalyst used is preferably 2 mass % or less, more preferably 5 to 5,000 ppm, based on the total amount of the compound represented by the above formula (3).

[0029] A solvent may be used in the addition reaction. The solvent is preferably one that can dissolve the compound represented by the above formula (3) and a compound having one addition-reactive carbon-carbon double bond in one molecule and having an epoxy group. Examples of solvents that can be used include hydrocarbon solvents such as pentane, hexane, cyclohexane, heptane, isooctane, toluene, xylene, and mesitylene; alcohol solvents such as methanol, ethanol, and isopropanol; aprotic polar solvents such as acetonitrile, propionitrile, N,N-dimethylformamide, and N-methylpyrrolidone; halogenated hydrocarbon solvents such as dichloromethane, dichloroethane, and chlorobenzene; and ether solvents such as diethyl ether, tetrahydrofuran, dioxane, and dimethoxyethane. These solvents may be used alone or in combination of two or more.

[0030] The reaction temperature is preferably 20 to 150°C, more preferably 60 to 100°C, from the viewpoints of improving productivity by shortening the reaction time and preventing side reactions and coloring of the product. The reaction time may be any time that allows the raw materials to be sufficiently consumed as the reaction proceeds, but from the viewpoint of production efficiency, it is preferably 10 minutes to 24 hours, more preferably 1 to 10 hours, and even more preferably 2 to 7 hours.

[0031] The weight-average molecular weight of the epoxy group-containing cyclic organopolysiloxane of the present invention is not particularly limited, but in consideration of imparting sufficient hardness and flex resistance to the cured product obtained by curing a curable composition containing the organopolysiloxane, the weight-average molecular weight is preferably 1,500 to 20,000, more preferably 2,000 to 15,000, and even more preferably 3,000 to 10,000. The weight-average molecular weight in the present invention is a value calculated using standard polystyrene as determined by gel permeation chromatography (GPC).

[0032] The epoxy functional group equivalent of the epoxy group-containing cyclic organopolysiloxane of the present invention is not particularly limited, but in consideration of imparting sufficient hardness and flex resistance to the cured product obtained by curing a curable composition containing the organopolysiloxane, it is preferably 200 to 400 g / mol, and more preferably 250 to 350 g / mol.

[0033] [2] Curable composition The curable composition of the present invention comprises (A) the above-described epoxy group-containing cyclic organopolysiloxane and (B) a curing agent.

[0034] The curing agent for component (B) is not particularly limited, but from the viewpoint of production efficiency, a photoacid generator (cationic photopolymerization initiator) that generates cationic species upon irradiation with light and initiates the curing reaction of a cationic curable compound is preferred.

[0035] Examples of photoacid generators include diazonium salt compounds, iodonium salt compounds, sulfonium salt compounds, phosphonium salt compounds, selenium salt compounds, oxonium salt compounds, ammonium salt compounds, bromine salt compounds, etc. Among these, in the present invention, it is preferable to use a sulfonium salt compound, since a cured product having excellent curability can be formed.

[0036] Examples of the cation moiety of the sulfonium salt compound include arylsulfonium ions (particularly triarylsulfonium ions), such as triphenylsulfonium ion, diphenyl[4-(phenylthio)phenyl]sulfonium ion, tri-p-tolylsulfonium ion, (4-hydroxyphenyl)methylbenzylsulfonium ion, and 4-(4-biphenylylthio)phenyl-4-biphenylylphenylsulfonium ion.

[0037] The anion portion may be, for example, [(Ar) s B(Phf) 4-s ] - (wherein Ar represents a phenyl group or a biphenylyl group; Phf represents a phenyl group in which at least one hydrogen atom is substituted with at least one selected from a perfluoroalkyl group, a perfluoroalkoxy group, and a halogen atom; and s represents an integer of 0 to 3), BF4 - , [(Rf) L PF 6-L ] - (wherein Rf represents an alkyl group in which 80% or more of the hydrogen atoms are substituted with fluorine atoms, and L is an integer of 0 to 5), AsF6 - , SbF6 - , pentafluorohydroxyantimonate, and the like.

[0038] Specific examples of the photoacid generator include (4-hydroxyphenyl)methylbenzylsulfonium tetrakis(pentafluorophenyl)borate, 4-(4-biphenylylthio)phenyl-4-biphenylylphenylsulfonium tetrakis(pentafluorophenyl)borate, 4-(phenylthio)phenyldiphenylsulfonium phenyltris(pentafluorophenyl)borate, [4-(4-biphenylylthio)phenyl]-4-biphenylylphenylsulfonium phenyltris(pentafluorophenyl)borate, diphenyl[4-(phenylthio)phenyl]sulfonium tris(pentafluoroethyl)trifluorophosphate, and diphenyl[4-(phenylthio)phenyl] Sulfonium tetrakis(pentafluorophenyl)borate, diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate, 4-(4-biphenylylthio)phenyl-4-biphenylylphenylsulfonium tris(pentafluoroethyl)trifluorophosphate, bis[4-(diphenylsulfonio)phenyl]sulfidophenyltris(pentafluorophenyl)borate, [4-(2-thioxanthonylthio)phenyl]phenyl-2-thioxanthonylsulfonium phenyltris(pentafluorophenyl)borate, 4-(phenylthio)phenyldiphenylsulfoniumHexafluoroantimonates and the like are exemplified, and these are commercially available under the trade names "Cyracure UVI-6970", "Cyracure UVI-6974", "Cyracure UVI-6990", "Cyracure UVI-950" (all manufactured by Union Carbide Corporation, USA), "Irgacure 250", "Irgacure 261", "Irgacure 264" (all manufactured by Chiba Specialty Chemicals), "SP-150", "SP-151", "SP-170", "Optomer SP-171" (all manufactured by ADEKA Corporation), "CG-24-61" (manufactured by Chiba Specialty Chemicals), "DAICAT II" (manufactured by Daicel Corporation), "UVAC1590", "UVAC1591" (all manufactured by Daicel-Cytec Co., Ltd.), "CI-2064", "CI-2639", "CI-2624", Commercially available products such as "CI-2481", "CI-2734", "CI-2855", "CI-2823", "CI-2758", "CIT-1682" (all manufactured by Nippon Soda Co., Ltd.), "PI-2074" (manufactured by Rhodia), tetrakis(pentafluorophenylborate) toluylcumyl iodonium salt), "FFC509" (manufactured by 3M), "BBI-102", "BBI-101", "BBI-103", "MPI-103", "TPS-103", "MDS-103", "DTS-103", "NAT-103", "NDS-103" (all manufactured by Midori Chemical Co., Ltd.), "CD-1010", "CD-1011", "CD-1012" (all manufactured by Sartomer), "CPI-100P", "CPI-101A", "CPI-200K" (all manufactured by San-Apro Co., Ltd.) can be used.

[0039] The curable composition of the present invention may contain a binder precursor other than the component (A) as the component (C), if necessary. The binder precursor is not particularly limited as long as it can be used as a binder, and examples thereof include various binder precursors such as thermoplastic resins such as (meth)acrylic resins and polyurethane resins; photocurable (meth)acrylic systems consisting of functional or polyfunctional (meth)acrylates; photo- or thermosetting epoxy systems consisting of monofunctional or polyfunctional epoxy compounds; thermosetting acid anhydride systems consisting of monofunctional or polyfunctional acid anhydrides; and thermosetting silicone systems using silanols. Among these, from the viewpoints of reactivity with the epoxy group-containing cyclic organopolysiloxane, productivity, and durability, photo- or thermosetting epoxy-based binder precursors made from monofunctional or polyfunctional epoxy compounds and thermosetting acid anhydride-based binder precursors made from monofunctional or polyfunctional acid anhydrides are preferred.

[0040] More preferred examples of the epoxy binder precursor include epoxy compounds having a molecular weight of 100 to 3,000, an epoxy group functional group equivalent of 100 to 300 g / mol, and two or more, preferably two, epoxy groups per molecule. In particular, epoxy compounds having a cyclic organopolysiloxane structure represented by the following formula (C1), similar to component (A), and having two or more, preferably 2 to 4, epoxy groups per molecule are suitable.

[0041] [ka] (In the formula, R 1 , R 2 , Z 1 , Z 2 , n1 and n2 have the same meaning as in the above formula (1), but Z 1 and Z 2 At least two of the above are epoxy-containing monovalent organic groups which may be interrupted by an oxygen atom.)

[0042] The blend amount of the component (C) is preferably 1 to 200 parts by mass, and more preferably 5 to 100 parts by mass, per 100 parts by mass of the component (A).

[0043] The curable composition of the present invention may be diluted with an organic solvent as needed. The organic solvent used in this case is preferably one that sufficiently dissolves the components and is non-reactive with the epoxy group or the curing catalyst. Specific examples of the organic solvent include aliphatic and / or aromatic hydrocarbon compounds, ester compounds, ketone compounds, and ether compounds. Among these, isododecane, toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and propylene glycol monomethyl ether acetate are preferred from the viewpoint of marketability.

[0044] The curable composition of the present invention may further contain, as optional components, inorganic fillers such as precipitated silica, wet silica, fumed silica, calcined silica, titanium oxide, alumina, glass, quartz, aluminosilicate, iron oxide, zinc oxide, calcium carbonate, carbon black, silicon carbide, silicon nitride, and boron nitride; inorganic fillers obtained by treating these fillers with organosilicon compounds such as organohalosilanes, organoalkoxysilanes, and organosilazanes; organic resin fine powders such as silicone resins, epoxy resins, and fluororesins; conductive metal powders such as silver and copper; curing aids; solvents (organic solvents, etc.); stabilizers (antioxidants, ultraviolet absorbers, light-resistant stabilizers, etc.); The composition may contain conventional additives such as stabilizers, heat stabilizers, heavy metal deactivators, flame retardants (phosphorus-based flame retardants, halogen-based flame retardants, inorganic flame retardants, etc.), flame retardant aids, reinforcing materials (other fillers, etc.), nucleating agents, coupling agents (silane coupling agents, etc.), lubricants, waxes, plasticizers, release agents, impact modifiers, color modifiers, clarifying agents, rheology modifiers (flow modifiers, etc.), processability modifiers, colorants (dyes, pigments, etc.), antistatic agents, dispersants, surface conditioners (antifoaming agents, leveling agents, anti-popping agents, etc.), surface modifiers (slip agents, etc.), matting agents, antifoaming agents, foam suppressors, defoamers, antibacterial agents, preservatives, viscosity modifiers, thickeners, photosensitizers, and foaming agents. These additives may be used alone or in combination of two or more.

[0045] The curable composition of the present invention can be cured by irradiation with light and / or heating to obtain a corresponding cured product. The form of the cured product is not particularly limited, and it may be a cured coating film on a substrate, or a self-standing cured molded product or sealed product. Photocuring is preferred as the curing method from the viewpoint of productivity. When photocuring the curable composition of the present invention, for example, the curable composition is applied to a substrate so as to form a desired film thickness, and then, after volatilizing the solvent as necessary, the composition is irradiated with ultraviolet light or an electron beam using a high-pressure mercury lamp, a metal halide lamp, an LED lamp, or the like. The irradiation atmosphere may be air or an inert gas such as nitrogen or argon. When irradiating with ultraviolet light, the intensity is, for example, 1 to 1,000 mJ / cm. 2 It is preferable to set it to about this level. On the other hand, the conditions for heat curing the curable composition of the present invention are not particularly limited, but are, for example, preferably 30 to 200° C., more preferably 50 to 190° C. The curing time can be set appropriately.

[0046] The substrate is not particularly limited, and examples thereof include organic resins such as plastic molded bodies, wood products, fibers, ceramics, glass, metals, and composites thereof. Among these, the curable composition of the present invention can be suitably used for various plastic materials, and can be particularly suitably used for polycarbonate resin, polystyrene resin, acrylic resin, modified acrylic resin, urethane resin, thiourethane resin, polycondensation product of halogenated bisphenol A and ethylene glycol, acrylic urethane resin, halogenated aryl group-containing acrylic resin, sulfur-containing resin, polyalkylene terephthalate resin, polyimide resin, polyamide resin, polycycloolefin resin, polyphenylene sulfide resin, polyphenylene oxide resin, cellulose resin, amorphous polyolefin resin, and composite resins thereof.

[0047] Furthermore, the surface of these resin substrates may be treated, specifically, by chemical conversion treatment, corona discharge treatment, flame treatment, plasma treatment, or acid or alkali solution treatment, or a laminate whose surface layer is coated with a resin different from that of the substrate itself may be used.Specific examples of the laminate include a laminate in which an acrylic resin layer or a urethane resin layer is present on the surface of a polycarbonate resin substrate produced by coextrusion or lamination, and a laminate in which an acrylic resin layer is present on the surface of a polyester resin substrate. The curable composition of the present invention may be applied directly to the surface of a substrate, or may be applied via a primer layer, an ultraviolet absorbing layer, a printing layer, a recording layer, a heat ray shielding layer, an adhesive layer, an inorganic vapor deposition film layer, or the like, as needed.

[0048] The coating method can be appropriately selected from known coating methods such as a spin coater, comma coater, lip coater, roll coater, die coater, knife coater, blade coater, rod coater, kiss coater, gravure coater, screen coating, dip coating, and cast coating.

[0049] Furthermore, if necessary, other coating layers such as an adhesive layer, an ultraviolet absorbing layer, a printing layer, a recording layer, a heat ray shielding layer, a pressure-sensitive adhesive layer, an inorganic vapor deposition film layer, a water- and oil-repellent layer, or a hydrophilic antifouling layer may be formed on the surface of the cured coating film of the coating composition of the present invention.

[0050] In addition to the method using a mold, the curable composition of the present invention can be formed into a self-supporting cured molded product by a film-forming method using a casting method in which the composition is coated on a film previously provided with a release layer and cured. The material of the mold is not particularly limited as long as it ensures releasability from the cured product obtained after curing, and may be, for example, a metal, glass, plastic, silicone, or Teflon (registered trademark, the same applies hereinafter)-coated mold, but it is preferable to use a Teflon-coated mold. In the present invention, a Teflon-coated mold has excellent releasability and can prevent damage to the cured product when the curable composition is removed.

[0051] The cured product obtained from the curable composition of the present invention has both crack resistance and flexibility, and therefore can be used in scratch-resistant coatings for plastic substrates, optical lenses, flexible display materials for electronic materials, optical encapsulants for LED devices, etc., as well as denture molding materials and dental filling agents. [Example]

[0052] The present invention will be described in more detail below with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to these examples. In the following examples, unless otherwise specified, "parts" and "%" mean "parts by mass" and "% by mass," respectively. The devices used in the examples are as follows:

[0053] (1) GPC measurement conditions Apparatus: Tosoh Corporation HLC-8320GPC Developing solvent: tetrahydrofuran (THF) Flow rate: 0.6mL / min Detector: Refractive index detector (RI) Column: TSK Guardcolumn SuperH-H TSKgel SuperHM-N(6.0mmI.D.×15cm×1) TSKgel SuperH2500(6.0mmI.D.×15cm×1) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 50 μL (2.0% by mass THF solution) Standard: Monodisperse polystyrene (2) Proton nuclear magnetic resonance spectrum ( 1 H-NMR) measurement conditions Equipment: BURKER AVANCE III 400 Solvent: CDCl3 Internal standard: tetramethylsilane (TMS) (3) Kinematic viscosity measurement conditions Measurements were made at 25°C using a Cannon-Fenske viscometer. (4) Viscosity measurement conditions Measurement was carried out at 25°C using a B-type rotational viscometer.

[0054] [1] Synthesis of cyclic organohydrogenpolysiloxane [Synthesis Example 1] A 500 mL four-neck flask equipped with a stirrer, condenser, dropping funnel, and thermometer was charged with 80 g of toluene and 115.2 g (0.48 mol) of 1,3,5,7-tetramethylcyclotetrasiloxane and heated to 117°C using an oil bath. 0.05 g of 5% platinum metal-loaded carbon powder was added, and 48 g (0.4 mol) of vinylnorbornene (trade name: V0062, manufactured by Tokyo Chemical Industry Co., Ltd.; a roughly equimolar isomer mixture of 5-vinylbicyclo[2.2.1]hept-2-ene and 6-vinylbicyclo[2.2.1]hept-2-ene) was added dropwise over 16 minutes with stirring. After the dropwise addition, the mixture was heated and stirred at 125°C for 16 hours and then cooled to room temperature. The platinum metal-loaded carbon was then removed by filtration, and the toluene was removed by distillation under reduced pressure to obtain a colorless, transparent, viscous liquid (A-0). The kinematic viscosity of this product at 25°C is 2,500 mm 2 / s, and the amount of SiH contained was 7.2 mmol / g on average.

[0055] The resulting viscous liquid (A-0) 1 Analysis by H-NMR and GPC measurements confirmed that the product was a mixture of the compounds shown below. Compound having one tetramethylcyclotetrasiloxane ring: approximately 6 mol % (a representative structural formula is shown in the following formula (9))

[0056] [ka]

[0057] Compound having two tetramethylcyclotetrasiloxane rings: approximately 25 mol % (a representative structural formula is shown in the following formula (10))

[0058] [ka]

[0059] Compound having three tetramethylcyclotetrasiloxane rings: approximately 16 mol % (an example of a representative structural formula is shown in the following formula (11), m = 2) Contains four tetramethylcyclotetrasiloxane rings: approximately 11 mol % (a typical structural formula is shown in the following formula (11), m = 3). Compound having 5 to 12 cyclotetrasiloxane rings: remainder (a representative structural formula is shown in the following formula (11), m = 4 to 11).

[0060] [ka]

[0061] [2] Synthesis of cyclic organopolysiloxane containing epoxy groups [Example 1-1] A 1-L separable flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer was charged with 124 parts (1 mole) of 1,2-epoxy-4-vinylcyclohexane, 121 parts of toluene, 37 parts of isopropanol, 0.12 parts of acetonitrile, and 0.0001 mole (platinum equivalent) of a toluene solution of platinum complex (Pt(0) 1,3-divinyltetramethyldisiloxane complex). The contents were then stirred and mixed. After heating, the flask reached an internal temperature of 85°C. 116 parts (Si-H; 0.83 moles) of the viscous liquid (A-0) obtained in Synthesis Example 1 were added dropwise over 1 hour. Simultaneously with the addition, a reaction occurred, generating heat and gradually increasing the reaction temperature from 85°C. The addition was continued while adjusting the reaction temperature so that it did not exceed 90°C. After the addition was completed, the reaction solution was aged for 6 hours while heating to maintain an internal temperature of 90°C. The amount of hydrogen gas generated from the reaction solution was then measured, confirming that no Si-H groups remained. Then, 0.02 parts of triphenylphosphine was added, and toluene, isopropanol, acetonitrile, and excess 1,2-epoxy-4-vinylcyclohexane were removed by distillation under reduced pressure (90°C, 5 mmHg), yielding a pale yellow viscous liquid (A-1) with a viscosity of 2,000 Pa·s or more at 25°C and an epoxy equivalent of 295 g / mol.1 The results of H-NMR measurement confirmed that the compound was a mixture (m=1 to 11) represented by the following formula (12).

[0062] [ka]

[0063] [Example 1-2] A 1-L separable flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer was charged with 114 parts (1 mole) of allyl glycidyl ether, 121 parts of toluene, 37 parts of isopropanol, 0.12 parts of acetonitrile, and 0.0001 mole (platinum equivalent) of a toluene solution of platinum complex (Pt(0) 1,3-divinyltetramethyldisiloxane complex). The contents were then stirred and mixed. After heating, the flask reached an internal temperature of 85°C. 116 parts (Si-H; 0.83 mole) of the viscous liquid (A-0) obtained in Synthesis Example was added dropwise over 1 hour. A reaction occurred simultaneously with the addition, generating heat, and the reaction temperature gradually rose from 85°C. The addition was continued while adjusting the reaction temperature so that it did not exceed 90°C. After the addition was completed, the reaction solution was aged for 6 hours while heating to maintain an internal temperature of 90°C. The amount of hydrogen gas generated from the reaction solution was then measured, confirming that no Si-H groups remained. Then, 0.02 parts of triphenylphosphine was added, and toluene, isopropanol, acetonitrile, and excess allyl glycidyl ether were removed by distillation under reduced pressure (90°C, 5 mmHg), yielding a pale yellow, highly viscous oil (A-2) with a viscosity of over 2,000 Pa·s at 25°C and an epoxy equivalent of 282 g / mol. 1 The results of H-NMR measurement confirmed that the compound was a mixture (m=1 to 11) represented by the following formula (13).

[0064] [ka]

[0065] [3] Preparation of curable coating composition and cured product [Examples 2-1 to 2-3, Comparative Examples 2-1 to 2-4] The components were mixed in the blending ratios shown in Table 1 to prepare curable coating compositions.

[0066] [Table 1]

[0067] (A-1): Epoxy group-containing cyclic organopolysiloxane obtained in Example 1-1 (A-2): Epoxy group-containing cyclic organopolysiloxane obtained in Example 1-2 (B-1): Non-antimony cationic photopolymerization initiator (manufactured by San-Apro Co., Ltd., "CPI-200K") (C-1): A cyclic siloxane represented by the following formula (14) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "X-40-2678", epoxy equivalent: 300) (C-2): Cyclic siloxane represented by the following formula (15) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KR-470", epoxy equivalent: 200) (C-3): Dimethylsiloxane having an epoxycyclohexyl structural group in the side chain and a viscosity of 280 mPa·s at 25°C (manufactured by Shin-Etsu Chemical Co., Ltd., product name "X-40-2715", epoxy equivalent weight 290) (C-4): Hydrocarbon-based bifunctional epoxycyclohexyl compound (Daicel Corporation, Celloxide 2021P)

[0068] [ka]

[0069] The curable coating compositions obtained in Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-4 were applied to the surface of a polycarbonate NF-2000 sheet (4 mm thick × 15 cm long × 10 cm wide) manufactured by Mitsubishi Engineering Plastics Corporation using a bar coater No. 14, and then air-dried for 15 minutes. After heating at 80°C for 1 minute, the coating was irradiated with 600 mJ / cm using a high-pressure mercury lamp. 2The coating film was cured by irradiation with light at an irradiation dose of 10 ...

[0070] The following evaluations were carried out on each test piece, and the results are shown in Table 2. (1) Coating appearance The coating film was visually inspected to determine whether or not there was any abnormality. ○: No abnormalities △: Colored ×: Foreign matter, unevenness, whitening abnormalities present (2) Initial haze The haze of the coated sheet was measured using a haze meter NDH5000SP manufactured by Nippon Denshoku Industries Co., Ltd., and the measured value was taken as the initial haze. (3) Scratch resistance In accordance with ASTM 1044, a Taber abrasion tester was fitted with an abrasion wheel CS-10F, and the haze value was measured after 100 revolutions under a load of 500 g. The difference in haze value before and after the test was taken as the scratch resistance. (4) Initial adhesion In accordance with JIS K5600, 25 grids were made by cutting six vertical and six horizontal cuts at 2 mm intervals in the coating film using a razor blade, and the cuts were thoroughly adhered with Scotch tape (registered trademark, manufactured by Nichiban Co., Ltd.). The tape was then rapidly peeled off at a 90° angle towards the user. The number of grids (X) that remained without the coating film peeling off was expressed as X / 25. (5) Boiling adhesion The test piece was immersed in boiling water for 2 hours, and the adhesion after that was evaluated in the same manner as the initial adhesion. (6) Pencil hardness Measurement was carried out by applying a load of 750 g in accordance with the pencil scratch test described in JIS K5600-5-4, and the results are shown. (7) Crack resistance (impact resistance) The impact strength was measured using a DuPont impact tester in accordance with the weight drop test specified in JIS K5600-5-3, and the results are shown below.

[0071] [Table 2]

[0072] As shown in Table 2, it is clear that the coating films formed from the curable coating compositions of Examples 2-1 to 2-3 achieve transparency, hardness, adhesion, and crack resistance. On the other hand, in Comparative Example 2-1, the hardness and adhesion were insufficient, and therefore the scratch resistance also tended to deteriorate; in Comparative Example 2-2, although the hardness was excellent, the flexibility of the film was poor and the crack resistance was insufficient; in Comparative Example 2-3, the hardness and flexibility were insufficient, and therefore the scratch resistance tended to deteriorate; and in Comparative Example 4, the polycarbonate substrate used was eroded, resulting in a deterioration in initial haze and insufficient hardness and flexibility.

[0073] [4] Preparation of curable composition for sheet molding [Examples 3-1 and 3-2, Comparative Examples 3-1 to 3-4] Curable compositions for sheet molding were prepared by mixing the components in the blending ratios shown in Table 3. The abbreviations in the table are the same as those described above.

[0074] [Table 3]

[0075] The compositions obtained in Examples 3-1 and 3-2 and Comparative Examples 3-1 to 3-4 were poured into a Teflon (registered trademark) coated mold (depth 0.3 mm × length 15 cm × width 10 cm), left to stand for 30 minutes, and then irradiated with 600 mJ / cm 2 using a high-pressure mercury lamp. 2 The composition was cured by irradiating it with light at an irradiation dose of 1000 to obtain a film-like test piece.

[0076] The following evaluations were carried out on each test piece, and the results are shown in Table 4. (8) Film appearance The test pieces obtained above were visually observed to determine whether or not there were any abnormalities. ○: No abnormalities ×: Abnormalities such as cracks (9) Film formability When the film was removed from the mold, it was observed whether it could stand on its own, and judged as follows: 〇: The film can be removed without any abnormalities. ×: Brittle and impossible to take out as a film. (10) 90° bending ability The test pieces obtained above were cut into strips 1 cm wide, 10 cm long, 1 cm wide, and 0.3 mm thick. Both short sides were picked up with tweezers and folded at 90°. The state of the film was observed and judged as follows: 〇: Can be bent without breaking. △: Some cracks occurred but no fracture occurred. ×: Completely broken and unable to bend. (11) Storage modulus, Tanδ(max) The test pieces obtained above were cut into strips 1 cm wide, and then cut into strips 10 cm long, 1 cm wide, and 0.3 mm thick. Using a viscoelasticity measuring device DMA7100 manufactured by Hitachi High-Tech Science Corporation, the temperature was raised from -50°C to 250°C at a heating rate of 10°C / min in an air atmosphere, and measurements were made in the tensile measurement mode.

[0077] [Table 4]

[0078] As shown in Table 4, it can be seen that the films obtained from the compositions of Examples 3-1 and 3-2 achieve good formability, flexibility, and hardness (storage modulus). On the other hand, in Comparative Example 3-1, although the moldability was good, the hardness (storage modulus) was low and a decrease in Tan δ(max), which corresponds to the glass transition temperature, was observed. In Comparative Example 3-2, the cured product was very brittle and had low crack resistance, so a film sufficient for measurement could not be obtained. In Comparative Examples 3-3 and 3-4, both the flexibility was insufficient and the films had poor hardness (storage modulus) compared to the Examples.

[0079] As described above, the cured products obtained using the epoxy group-containing cyclic organopolysiloxane of the present invention combine hardness and flexibility and are suitable for use as hard coating layers on plastic substrates, lens materials, sealants, and other cured molded products.

Claims

1. An epoxy group-containing cyclic organopolysiloxane represented by the following general formula (1): 【Chemistry 1】 (In the formula, R 1 , R 2 , R 3 and R 4 each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms which may be interrupted by an oxygen atom, Y represents a divalent saturated hydrocarbon group having a polycyclic structure; Z 1 and Z 2 each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms which may be interrupted by an oxygen atom, an epoxy group-containing monovalent organic group which may be interrupted by an oxygen atom, or an alkoxysilylalkyl group, but at least one of them is an epoxy group-containing monovalent organic group which may be interrupted by an oxygen atom; n1 and n2 each independently represent an integer of 1 to 5 and satisfy the relationship n1+n2=3 to 6; n3 and n4 each independently represent an integer of 1 to 5 and satisfy the relationship n3+n4=3 to 6; m represents an integer of 1 to 11.

2. The R 1 , R 2 , R 3 and R 4 2. The epoxy group-containing cyclic organopolysiloxane according to claim 1, wherein is a methyl group.

3. Said Z 1 and Z 2 2. The epoxy group-containing cyclic organopolysiloxane according to claim 1, wherein is at least one selected from the group consisting of a 3-glycidyloxypropyl group and a 2-(3,4-epoxycyclohexyl)ethyl group.

4. 2. The epoxy group-containing cyclic organopolysiloxane according to claim 1, wherein Y is at least one divalent saturated hydrocarbon group selected from the group consisting of divalent saturated hydrocarbon groups represented by the following formulae (2a) and (2b): 【Chemistry 2】 (In the formula, an asterisk (*) indicates the bonding site to the silicon atom, and the configuration at each asymmetric carbon may be either cis (exo) or trans (endo).)

5. 2. The epoxy group-containing cyclic organopolysiloxane according to claim 1, wherein n1 and n4 are 3, and n2 and n3 are 1.

6. 2. The epoxy-containing cyclic organopolysiloxane according to claim 1, wherein the functional group equivalent weight of the epoxy group is 200 to 400 g / mol.

7. (A) 100 parts by mass of the epoxy group-containing cyclic organopolysiloxane according to any one of claims 1 to 6, and (B) Curing agent: 0.01 to 5 parts by mass A curable composition comprising:

8. The curable composition according to claim 7, further comprising: (C) 1 to 200 parts by mass of an epoxy group-containing compound other than (A).

9. The curable composition according to claim 8, wherein the curing agent is a photoacid generator.

10. A cured product obtained by curing the curable composition according to claim 8.

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