Silicone resin composition, molded body, laminate, and method for manufacturing molded body

Abstract

The present invention provides a photocurable silicone resin composition capable of obtaining a molded article having excellent pencil hardness, scratch resistance and bending resistance, and a silicone resin molded article as a three-dimensional crosslinked body obtained by hardening the same. A photocurable silicone resin composition is formulated in a mass ratio of 1 to 50: 10 to 40: 10 to 80 with: a reactive silicone resin (A); a polyfunctional epoxyalkane-modified unsaturated compound (B) containing at least two -R 3 -CR 4 =CH2 or -CR 4 =CH2 [wherein, R 3 represents an alkylene group, a secondary alkylene group or an -O-C(=O)- group, and R 4 represents a hydrogen atom or an alkyl group] and further having an epoxyalkane-modified moiety; and a polyfunctional unsaturated compound (C) containing two or more of the above-mentioned unsaturated groups and not containing an epoxyalkane-modified moiety.

Description

Technical Field

[0001] The present invention relates to a photocurable silicone resin composition capable of obtaining a molded article having excellent pencil hardness, scratch resistance, bend resistance, etc., and a silicone resin molded article as a three-dimensional crosslinked body obtained by curing the same, and particularly relates to a silicone resin composition, a molded article, a laminate, and a method for manufacturing a molded article. Background Art

[0002] In recent years, in all fields such as displays, mobile devices, household appliances, and automotive parts, the demand for design, lightweight, and thinness has been increasing. As surface protection members for these, plastics or lightweight metals can be used instead of conventional glass or metal. However, plastics or some lightweight metals have the problem of low surface hardness and being easily damaged. Therefore, a method of providing a hard coating for protecting the surface can be used.

[0003] Most of the hard coatings use acrylic-based compositions. Acrylic-based compositions are usually film-formed and cured by a radical reaction using active energy rays such as ultraviolet rays or electron beams, so they can be cured in a short time and at a low temperature, and can maintain toughness through the formulated resin composition, so they can be widely used in coatings, adhesives, etc.

[0004] As an example of the hard coating, the present inventors focused on a reactive silicone resin having a cage structure and a reactive functional group and conducted research. It was found that by increasing the number of reactive functional groups in the reactive silicone resin having a cage structure and formulating an unsaturated compound capable of radical copolymerization with it at a specific ratio, a silicone resin molded article having excellent balance of high surface hardness, heat resistance, mechanical properties, and dimensional stability and being transparent can be provided, and it was disclosed that it can be preferably used as an alternative to inorganic glass (Patent Documents 1 to 2). In addition, a method for manufacturing the reactive silicone resin having a cage structure was particularly disclosed in Patent Document 3.

[0005] However, with respect to the silicone resin composition, although it has a high surface hardness, there is a problem of cracks or peeling occurring during bending.

[0006] [Prior Art Documents]

[0007] [Patent Documents]

[0008] Patent Document 1: Japanese Patent No. 4558643 Gazette

[0009] Patent Document 2: Japanese Patent No. 5698566 Gazette

[0010] Patent Document 3: Japanese Patent Laid-Open No. 2004-143449 Gazette Summary of the Invention

[0011] [Problems to be Solved by the Invention]

[0012] An object of the present invention is to provide a photocurable silicone resin composition capable of obtaining a molded article having excellent high pencil hardness, scratch resistance, and flexural resistance, and a silicone resin molded article obtained by curing the composition and being a three-dimensional crosslinked body.

[0013] [Technical Means for Solving the Problems]

[0014] The present inventors have found that for such a photocurable silicone resin composition, the above problems are solved by containing, as an unsaturated compound capable of radical polymerization in its composition, a polymerizable compound having a specific structure in a specific ratio, thereby completing the present invention.

[0015] That is, the present invention is a photocurable silicone resin composition formulated in a mass ratio of 1 to 50: 10 to 40: 10 to 80 with: a reactive silicone resin (A); a polyfunctional alkylene oxide-modified unsaturated compound (B) containing at least two -R 3 -CR 4 =CH2 or -CR 4 =CH2 [wherein, R 3 represents an alkylene group, an alkylidene group, or an -O-C(=O)- group, and R 4 represents a hydrogen atom or an alkyl group] and further having an alkylene oxide modification site; and a polyfunctional unsaturated compound (C) containing two or more of the above unsaturated groups and not containing an alkylene oxide modification site.

[0016] [Effects of the Invention]

[0017] According to the present invention, there can be provided a photocurable silicone resin composition capable of obtaining a molded article having excellent high pencil hardness, scratch resistance, and flexural resistance, and a silicone resin molded article obtained by curing the composition and being a three-dimensional crosslinked body. Detailed Description of the Invention

[0018] Hereinafter, each element constituting the present invention will be described in detail. The following description is an example of an embodiment of the present invention, and the present invention is not limited to the following description as long as it does not exceed its gist. Further, in this specification, when the expression "~" is used, it is used as an expression including the numerical values or physical property values before and after it. In addition, in the present invention, when the expression "(meth)acrylic acid" is used, it means one or both of "acrylic acid" and "methacrylic acid". The same applies to "(meth)acrylate" and "(meth)acryloyl".

[0019] The photocurable silicone resin composition of the present invention is characterized in that it is formulated in a mass ratio of 1 to 50: 10 to 40: 10 to 80 with: a reactive silicone resin (A); a polyfunctional epoxyalkane-modified unsaturated compound (B) containing at least two -R 3 -CR 4 =CH2 or -CR 4 =CH2 [wherein, R 3 represents an alkylene group, a sub-alkylene group or an -O-C(=O)- group, and R 4 represents a hydrogen atom or an alkyl group] and further having an epoxyalkane-modified moiety; and a polyfunctional unsaturated compound (C) containing two or more of the above-mentioned unsaturated groups and not containing an epoxyalkane-modified moiety.

[0020] The reactive silicone resin (A) used in the present invention can be formulated in a mass ratio of 1 to 50 relative to 100 parts by mass of the photocurable silicone resin composition, and more preferably in a mass ratio of 2.5 to 30. When less than 1 part by mass, the crosslinking density decreases and it becomes soft, and the abrasion resistance and pencil hardness deteriorate. When more than 50 parts by mass, the crosslinking density increases and it becomes hard and brittle, and cracks or peeling occur during bending.

[0021] As the reactive silicone resin (A), known silicone resins can be used, and a preferred form is a form mainly composed of polyorganosilsesquioxane represented by the following general formula (1) and having a cage structure in the structural unit (also called cage-shaped polyorganosilsesquioxane. Polyorganosilsesquioxane is also called silsesquioxane). In the general formula (1), R is an organic functional group having a (meth)acryloyl group, and n is 8, 10 or 12.

[0022] [RSiO 3 / 2 n (1)

[0023] In the general formula (1), R is an organic functional group having a (meth)acryloyl group, and n is 8, 10 or 12. As the organic functional group having a (meth)acryloyl group, a group represented by the following general formula (4) can be cited. In the general formula (4), m is an integer of 1 to 3, and R 1 ​is a hydrogen atom or a methyl group.

[0024] CH2=CR 1 -COO-(CH2) m - (4)

[0025] The reactive silicone resin contains an organic functional group having a (meth)acryloyl group on the silicon atom in the molecule. As specific structures of the cage-type polyorganosilsesquioxane where n in the general formula (1) is 8, 10, or 12, cage-type structures represented by the following structural formulas (5), (6), and (7) can be respectively cited. Furthermore, R in the following formulas represents the same as R in the general formula (1).

[0026] [Chemical formula 1]

[0027]

[0028]

[0029]

[0030] Here, the reactive silicone resin can be produced by the method described in Patent Document 3 and the like. For example, a silicon compound represented by RSiX3 can be subjected to a hydrolysis reaction in the presence of a polar solvent and a basic catalyst, and at the same time, a part of it can be condensed, and the obtained hydrolysis product can be further condensed in the presence of a non-polar solvent and a basic catalyst. Here, R is an organic functional group having a (meth)acryloyl group, specifically, the group represented by the general formula (4), and X represents a hydrolyzable group. If specific examples of preferred R are shown, 3-methacryloyloxypropyl, methacryloxymethyl, and 3-acryloyloxypropyl can be cited.

[0031] The hydrolyzable group X is not particularly limited as long as it is a hydrolyzable group, and alkoxy groups, acetoxy groups, etc. can be cited, and alkoxy groups are preferred. As the alkoxy group, methoxy, ethoxy, n-propoxy or isopropoxy, or n-butoxy, isobutoxy or tert-butoxy, etc. can be cited. Methoxy is preferred because of its high reactivity.

[0032] If preferred compounds in the silicon compound represented by RSiX3 are shown, the following can be cited: methacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxysilane, 3-methacryloyloxypropyltrichlorosilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrichlorosilane. Among them, 3-methacryloyloxypropyltrimethoxysilane, which is easy to obtain as a raw material, is preferably used.

[0033] As the basic catalyst used in the hydrolysis reaction, examples thereof include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, cesium hydroxide, or ammonium hydroxide salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide. Among these basic catalysts, in terms of high catalyst activity, tetramethylammonium hydroxide can be preferably used. The basic catalyst is usually used as an aqueous solution.

[0034] Regarding the hydrolysis reaction conditions, the reaction temperature is preferably 0°C to 60°C, more preferably 20°C to 40°C. If the reaction temperature is lower than 0°C, the reaction rate becomes slow and the hydrolyzable group remains in an unreacted state, resulting in a large amount of reaction time being spent. On the other hand, if it is higher than 60°C, the reaction rate is too fast, so a complex condensation reaction occurs, resulting in the promotion of the high molecular weight of the hydrolysis product. In addition, the reaction time is preferably 2 hours or more. If the reaction time is less than 2 hours, there is a risk that the hydrolysis reaction is not fully carried out and the hydrolyzable group remains in an unreacted state.

[0035] The hydrolysis reaction requires the presence of water, which can also be supplied by the aqueous solution of the basic catalyst or added in the form of additional water. The amount of water can be more than the amount sufficient to hydrolyze the hydrolyzable group, preferably 1.0 to 1.5 times the theoretical amount. In addition, an organic polar solvent must be used during hydrolysis. As the organic polar solvent, alcohols such as methanol, ethanol, 2-propanol, or other organic polar solvents can be used. Lower alcohols having 1 to 6 carbon atoms that are soluble in water are preferred, and 2-propanol is more preferably used. If a non-polar solvent is used, the reaction system is non-uniform, the hydrolysis reaction is not fully carried out, and unreacted hydrolyzable groups remain, which is not good.

[0036] After the hydrolysis reaction is completed, water or the reaction solvent containing water is separated. The separation of water or the reaction solvent containing water can be carried out by methods such as vacuum evaporation. In order to sufficiently remove water or other impurities, methods such as adding a non-polar solvent to dissolve the hydrolysis reaction product, washing the solution with brine, and then drying with a desiccant such as anhydrous magnesium sulfate can be used. If the non-polar solvent is separated by methods such as evaporation, the hydrolysis reaction product can be recovered. If the non-polar solvent can be used as the non-polar solvent used in the next reaction, it does not need to be separated.

[0037] In the hydrolysis reaction, a condensation reaction of the hydrolyzate occurs together with the hydrolysis. The hydrolysis product accompanied by the condensation reaction of the hydrolyzate usually becomes a colorless viscous liquid with a number average molecular weight of 1400 to 5000. The hydrolysis product varies depending on the reaction conditions and becomes an oligomer with a number average molecular weight of 1400 to 3000. Most, preferably almost all, of the hydrolyzable groups X are replaced by OH groups, and furthermore, most, preferably more than 95%, of the OH groups are condensed. The structure of the hydrolysis product is a variety of cage-type, ladder-type, and random-type silsesquioxanes. Even for a compound with a cage structure, the proportion of the complete cage structure is small, and mainly an incomplete cage structure with a part of the cage opened. Therefore, the hydrolysis product obtained in the hydrolysis is further heated in an organic solvent in the presence of a basic catalyst to condense the siloxane bonds (referred to as recondensation), thereby selectively producing a cage-type silsesquioxane.

[0038] Specifically, it is carried out as follows. That is, as described above, after separating water or the water-containing reaction solvent after the hydrolysis reaction, the recondensation reaction is carried out in the presence of a nonpolar solvent and a basic catalyst. Regarding the reaction conditions of the recondensation reaction, the reaction temperature is preferably in the range of 100°C to 200°C, and more preferably in the range of 110°C to 140°C. In addition, if the reaction temperature is too low, sufficient driving force for the recondensation reaction cannot be obtained and the reaction does not proceed. If the reaction temperature is too high, (meth)acryloyl groups may undergo a self-polymerization reaction, so it is necessary to control the reaction temperature or add a polymerization inhibitor, etc. The reaction time is preferably 2 hours to 12 hours. The amount of the nonpolar solvent used can be an amount sufficient to dissolve the hydrolysis reaction product, and the amount of the basic catalyst used can be in the range of 0.1 mass% to 10 mass% (wt%) relative to the hydrolysis reaction product.

[0039] As the nonpolar solvent, any solvent that is insoluble or almost insoluble in water can be used, and a hydrocarbon-based solvent is preferred. The hydrocarbon-based solvent includes nonpolar solvents with low boiling points such as toluene, benzene, and xylene. Among them, toluene is preferably used. In addition, as the basic catalyst, the basic catalyst used in the hydrolysis reaction can be used, and examples include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, and cesium hydroxide, or ammonium hydroxide salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, and benzyltriethylammonium hydroxide, but a catalyst that is soluble in a nonpolar solvent such as a tetraalkylammonium is preferred.

[0040] In addition, the hydrolysis product used in recondensation is preferably a hydrolysis product that has been washed with water, dehydrated, and concentrated, but it may also be used without washing with water or dehydration. During the above reaction, water may be present, but it is not necessary to actively add it, and it may be limited to the amount of water introduced by the alkaline catalyst solution. Furthermore, in the case where the hydrolysis of the hydrolysis product is not sufficiently carried out, the amount of water must be more than the theoretical amount required for the hydrolyzable groups remaining after hydrolysis, but usually the hydrolysis reaction proceeds sufficiently. After the recondensation reaction, the catalyst is removed by washing with water and concentrated to obtain a silsesquioxane mixture. The obtained silsesquioxane mixture preferably has an equal number of silicon atoms and (meth)acryloyl groups in the molecule.

[0041] The silsesquioxane mixture obtained in the above manner varies depending on the reaction conditions or the state of the hydrolysis product, and it is considered that the constituent components are more than 70% of various cage silsesquioxanes as a whole, and the remainder is trapezoidal or randomly crosslinked silsesquioxanes. Since these are difficult to separate and require a great deal of effort, in the present invention, when using the cage silsesquioxane represented by the general formula (1), it is preferably a silsesquioxane containing more than 70% of various cage silsesquioxanes. Furthermore, if the content of the cage silsesquioxane is 70% or more, there is no difference in the obtained effects. Among the constituent components of the various cage silsesquioxanes, T8 represented by the general formula (5) is 20% to 40%, T10 represented by the general formula (6) is 40% to 50%, and the other components are T12 represented by the general formula (7). T8 can be precipitated and separated as needle-like crystals by allowing the silsesquioxane mixture to stand at 20°C or lower. Furthermore, regarding the content ratio of the cage silsesquioxane, for example, it can be confirmed using gel permeation chromatography (GPC) or liquid chromatograph mass spectrometer (LC-MS).

[0042] The reactive silicone resin may be a mixture of T8 to T12, or may be one or two obtained by separating or concentrating T8, etc., but is not limited to the reactive silicone resin obtained by the above production method.

[0043] The polyfunctional epoxyalkane-modified unsaturated compound (B) contains at least two -R 3 -CR 4 =CH2 or -CR 4 =CH2 [wherein, R 3 represents an alkylene group, a sub-alkylene group, or an -O-C(=O)- group, R 4An unsaturated group represented by [hydrogen atom or alkyl group] and having an alkylene oxide modification site. Here, for the alkylene oxide modification site, ethylene oxide or propylene oxide is preferred. In addition, it is preferred to contain at least one alkylene oxide modification site relative to one unsaturated group. By containing component (B), cracks or peeling during bending can be suppressed while maintaining high surface hardness.

[0044] The polyfunctional alkylene oxide-modified unsaturated compound (B) is preferably formulated in a mass ratio of 10 to 40, more preferably 10 to 30, based on 100 parts by mass of the photocurable silicone resin composition. When less than 10 parts by mass, sufficient flexibility cannot be imparted, and cracks or peeling will occur during bending. When more than 40 parts by mass, the surface hardness decreases, which causes a decrease in pencil hardness and scratch resistance.

[0045] Examples of the polyfunctional alkylene oxide-modified unsaturated compound (B) include: alkylene oxide-modified glycerol tri(meth)acrylate, alkylene oxide-modified diglycerol tetra(meth)acrylate, alkylene oxide-modified dipentaerythritol tetra(meth)acrylate, alkylene oxide-modified dipentaerythritol hexa(meth)acrylate, polyethylene glycol acrylate, polypropylene glycol acrylate, etc. Furthermore, these component (B) can be used alone or in combination of two or more.

[0046] Specifically, examples include: trimethylolpropane triacrylate modified with 3 moles of ethylene oxide, trimethylolpropane triacrylate modified with 6 moles of ethylene oxide, trimethylolpropane triacrylate modified with 9 moles of ethylene oxide, trimethylolpropane triacrylate modified with 3 moles of propylene oxide, pentaerythritol tetraacrylate modified with 4 moles of ethylene oxide, pentaerythritol tetraacrylate modified with 5 moles of ethylene oxide, dipentaerythritol hexaacrylate modified with 6 moles of ethylene oxide, dipentaerythritol hexaacrylate modified with 12 moles of ethylene oxide, glycerol triacrylate modified with 3 moles of ethylene oxide, glycerol triacrylate modified with 3 moles of propylene oxide, diglycerol tetraacrylate modified with 4 moles of ethylene oxide, triethylene glycol diacrylate, polyethylene glycol diacrylate, bisphenol A diacrylate modified with 3 moles of ethylene oxide, bisphenol A diacrylate modified with 4 moles of ethylene oxide, bisphenol A diacrylate modified with 10 moles of ethylene oxide, bisphenol F diacrylate modified with 4 moles of ethylene oxide, polyethylene glycol diacrylate, polypropylene glycol diacrylate, etc. Among these compounds, from the viewpoint of surface hardness, compounds having three or more polymerizable unsaturated groups are more preferred. From the viewpoint of suppressing cracks or peeling during bending, polyfunctional alkylene oxide-modified unsaturated compounds containing at least one alkylene oxide site relative to one unsaturated group are preferred.

[0047] The polyfunctional unsaturated compound (C) that does not contain an alkylene oxide modification site contains -R in the molecule 3 -CR 4=CH2 or -CR 4 =CH2 [wherein, R 3 represents an alkylene group, a sub-alkylene group or an -O-C(=O)- group, and R 4 represents a hydrogen atom or an alkyl group], and is preferably a polyfunctional unsaturated compound containing at least two unsaturated groups, and more preferably containing 20% by mass or more of hydroxyl groups in 100% by mass of the component (C).

[0048] The polyfunctional unsaturated compound (C) not containing an alkylene oxide modification site should preferably be in a mass ratio of 10 to 80, more preferably 30 to 80, relative to 100 parts by mass of the photocurable silicone resin composition. When less than 10 parts by mass, crosslinking becomes insufficient and the abrasion resistance and pencil hardness deteriorate. When more than 80 parts by mass, the crosslinking density increases and it becomes hard and brittle, and cracks or peeling occur during bending.

[0049] The polyfunctional unsaturated compound (C) not containing an alkylene oxide modification site preferably contains 10% to 100% by mass of a polyfunctional unsaturated compound having two or more or three or more of the above unsaturated groups. By blending the polyfunctional unsaturated compound, a molded article with high surface hardness can be obtained.

[0050] Examples of the unsaturated compound containing a hydroxyl group in the polyfunctional unsaturated compound include pentaerythritol triacrylate, glycerol dimethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetraacrylate, etc. Since these have hydroxyl groups in the molecule, the radicals generated by shortening the distance between molecules due to the interaction of the hydroxyl groups react rapidly with the double bonds, thereby increasing the hardening speed. Radical polymerization is carried out before the reaction of oxygen with the radicals, so that the hardening hindrance caused by oxygen can be suppressed.

[0051] As described above, regarding the polyfunctional unsaturated compound (C) without an alkylene oxide modification site formulated in the silicone resin composition, it is preferably an unsaturated compound containing 20% by mass or more of hydroxyl groups, and more preferably an unsaturated compound containing 30% by mass or more of hydroxyl groups in (C). If it is within the above range, the intermolecular interaction is effective. There is no particular upper limit for the blending amount, but if it exceeds 60% by mass, the effect of suppressing oxygen hindrance hardly increases.

[0052] On the other hand, examples of the polyfunctional unsaturated compound without a hydroxyl group include trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, etc. In addition to these, the following compounds can also be used: all the terminal hydroxyl groups of the skeleton obtained by modifying a part or all of the hydroxyl groups of pentaerythritol or dipentaerythritol with ethylene, isopropylene and other diols or γ-butyrolactone are further modified with -R 3 -CR 4=CH2 or -CR 4 =CH2 [wherein, R 3 represents an alkylene group, a sub-alkylene group or an -O-C(=O)- group, and R 4 represents a hydrogen atom or an alkyl group] and compounds modified with an unsaturated group represented thereby, etc. Alternatively, urethane acrylates, acrylic acid copolymers, etc. can be exemplified. In addition, these polyfunctional unsaturated compounds or unsaturated compounds without a hydroxyl group can be used alone or in combination of two or more thereof.

[0053] In addition, in the polyfunctional unsaturated compound (C) not containing an alkylene oxide modification site, a reactive monofunctional or other difunctional monomer (unsaturated compound) can be blended within a range not reducing the surface hardness. Examples of the monofunctional monomer include styrene, vinyl acetate, N-vinylpyrrolidone, butyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-decyl acrylate, isobornyl acrylate, dicyclopentenoxyethyl acrylate, phenoxyethyl acrylate, trifluoroethyl methacrylate, etc. Examples of the other difunctional monomer include tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol A diglycidyl ether diacrylate, tetraethylene glycol diacrylate, hydroxypivalic acid neopentyl glycol diacrylate, etc.

[0054] The monofunctional monomer or the other difunctional monomer is preferably contained in the polyfunctional unsaturated compound (C) not containing an alkylene oxide modification site in an amount of 20% by mass or less, more preferably 10% by mass or less. If blended in an amount exceeding 20%, there is a tendency for the surface hardness to decrease, and thus it is not good.

[0055] The photocurable silicone resin composition of the present invention preferably further contains an active energy ray polymerization initiator (D). The active energy ray polymerization initiator (D) is 0.1 part by mass to 20 parts by mass, preferably 1 part by mass to 10 parts by mass, based on 100 parts by mass of the photocurable silicone resin composition. If this range is not satisfied, crosslinking cannot be inhibited, or the abrasion resistance and pencil hardness deteriorate. On the contrary, if it is contained in an amount exceeding this range, further improvement in the reaction rate may not be expected.

[0056] As the active energy ray polymerization initiator (D), compounds of, for example, benzoin type, acetophenone type, anthraquinone type, thioxanthone type, ketal type, and phosphine oxide type can be preferably used. In addition, a photoinitiator aid or a photosensitizer that exerts an effect in combination with a photoinitiator can also be used.

[0057] As a specific active energy ray polymerization initiator (D), examples of the benzoin series as a photoinitiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, etc.; examples of the acetophenone series include acetophenone, 2,2 - diethoxy - 2 - phenylacetophenone, 2,2 - diethoxy - 2 - phenylacetophenone, 1,1 - dichloroacetophenone, 2 - hydroxy - 2 - methyl - phenylpropan - 1 - one, diethoxyacetophenone, 1 - hydroxycyclohexyl phenyl ketone, 2 - methyl - 1 - [4 - (methylthio)phenyl] - 2 - morpholinopropan - 1 - one, etc.; examples of the anthraquinones include 2 - ethylanthraquinone, 2 - tert - butylanthraquinone, 2 - chloroanthraquinone, 2 - pentylanthraquinone, etc.; examples of the thioxanthones include 2,4 - diethylthioxanthone, 2 - isopropylthioxanthone, 2 - chlorothioxanthone, etc.; examples of the ketals include acetophenone dimethyl ketal, benzyl dimethyl ketal, etc.; examples of the benzophenones include benzophenone, 4 - benzoyl - 4'-methyl diphenyl sulfide, 4,4'-dimethylamino benzophenone, etc.; examples of the phosphine oxides include 2,4,6 - trimethylbenzoyl diphenyl phosphine oxide, bis(2,4,6 - trimethylbenzoyl) - phenyl phosphine oxide, etc. They can be used alone or as a mixture of two or more, and further can be used in combination with photoinitiator aids such as tertiary amines like triethanolamine and methyldiethanolamine, and benzoic acid derivatives like ethyl N,N - dimethylaminobenzoate and isopentyl N,N - dimethylaminobenzoate.

[0058] As the photosensitizer, naphthalene series such as 1,4 - dimethoxynaphthalene, 1,4 - diethoxynaphthalene, 1,4 - bis(n - propoxy)naphthalene, 1,4 - bis(isopropoxy)naphthalene, 2,6 - dimethoxynaphthalene, 2,6 - diethoxynaphthalene, 2,6 - bis(n - propoxy)naphthalene, 2,6 - bis(isopropoxy)naphthalene, etc., or benzophenone series such as benzophenone, 4 - methylbenzophenone, 4 - (methylphenylthio)phenyl - phenylmethane, 4,4'-bis(diethylamino)benzophenone, etc. can be preferably cited. As the blending amount, from the viewpoints of photocurability and transparency, it is in the range of 0.05 parts by mass to 3 parts by mass, preferably in the range of 0.1 parts by mass to 3 parts by mass, relative to the photocurable silicone resin composition. If it is less than 0.05 parts by mass, the enhancing effect of the photosensitizer will not be exerted, and the expected hardness enhancing effect cannot be obtained. In addition, if it exceeds 3 parts by mass, there is a tendency for the coloring to become stronger, so it is preferably used within the above range. In order to adjust the photocurability or transparency, multiple photosensitizers can also be combined.

[0059] The photocurable silicone resin molded article of the present invention can be manufactured by irradiating the photocurable silicone resin composition with active energy rays such as visible light, ultraviolet rays, or electron beams to harden it. Preferably, by irradiating ultraviolet rays with a wavelength of 10 nm to 400 nm or visible light with a wavelength of 400 nm to 700 nm, a hardened molded article can be obtained. The wavelength of the light used is not particularly limited, and in particular, near-ultraviolet rays with a wavelength of 200 nm to 400 nm can be preferably used. As lamps that can be used as ultraviolet ray sources, low-pressure mercury lamps (output: 0.4 W / cm to 4 W / cm), high-pressure mercury lamps (40 W / cm to 160 W / cm), ultra-high-pressure mercury lamps (173 W / cm to 435 W / cm), metal halide lamps (80 W / cm to 160 W / cm), etc. can be exemplified.

[0060] As a method for obtaining a molded article (silicone resin copolymer or hardened product) by irradiating active energy rays such as light irradiation, it can be either in an oxygen-blocking environment or in an atmospheric environment. However, even when the composition of the present invention is polymerized and hardened in an atmospheric environment, a good molded article can be obtained. Therefore, it is preferably carried out in an atmospheric environment. For example, the following methods can be exemplified: injecting the photocurable silicone resin composition of the present invention into a mold having an arbitrary cavity shape and made of a transparent raw material such as quartz glass, irradiating ultraviolet rays with an ultraviolet lamp to carry out polymerization and hardening, and demolding it from the mold to manufacture a molded article having a desired shape; or without using a mold, for example, coating the photocurable silicone resin composition of the present invention on a moving steel belt using a doctor blade or a roll coater, and polymerizing and hardening it with an ultraviolet lamp to manufacture a sheet-shaped molded article, etc.

[0061] The shape of the molded article is arbitrary and can be a film or a coating film, etc. The molded article can be obtained by subjecting the photocurable silicone resin composition of the present invention to radical copolymerization and hardening it. The molded article or hardened product of the present invention is a three-dimensional cross-linked polymer. In this case, the same molding and hardening method as that of a thermosetting resin can be adopted.

[0062] Furthermore, the following method can be exemplified: Coating the photocurable silicone resin composition of the present invention on various substrates such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), triacetyl cellulose (TAC), colorless polyimide (CPI), polyimide (PI), metal plate, and glass, or diluting with various organic solvents and then coating and curing, thereby forming a shaped body as a hard coat film on the substrate surface. Specifically, casting method, roll coating method, bar coating method, spray coating method, air knife coating method, spin coating method, flow coating method, curtain coating method, and dipping method can be cited. Moreover, the coating film thickness is adjusted according to the solid content concentration in consideration of the formed film thickness after drying and curing by an ultraviolet lamp. When an organic solvent is used for adjusting the solid content concentration, it is preferably removed by drying or the like after coating. The drying temperature is set under the condition that the used substrate does not deform, and from the viewpoint of productivity, the drying time is preferably 1 hour or less. In addition, from the viewpoints of scratch resistance and adhesion, the thickness of the hard coat film is 0.5 μm to 100 μm, preferably 1 μm to 60 μm.

[0063] As specific examples of the organic solvent, the following can be used: aromatic organic solvents such as toluene and xylene; ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester organic solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate, and isobutyl acetate; alcohol organic solvents such as methanol, ethanol, n-propanol, isopropanol, and n-butanol; glycol ether organic solvents such as propylene glycol monomethyl ether and the like. Particularly preferably, it contains a glycol organic solvent.

[0064] As the glycol ether organic solvent, for example, the following can be cited: ethylene glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol dipropyl ether, ethylene glycol monobutyl ether, ethylene glycol mono-isobutyl ether, ethylene glycol dibutyl ether, ethylene glycol isoamyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, methoxyethoxyethanol, and ethylene glycol monoallyl ether; propylene glycols such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and butoxypropanol. Among them, propylene glycol monomethyl ether is preferred.

[0065] The pencil hardness (in accordance with Japanese Industrial Standards (JIS) K5600) of a laminate (photo-curable silicone resin laminate) including the resin molded body of the present invention obtained in the above-described manner is 2H or higher, preferably 3H or higher. Regarding scratch resistance, it is preferably not damaged in a steel wool test at least under a load of 1,500 g and reciprocated 300 times. Further, as flexural resistance, it is preferably such that when a test piece of 80 mm × 50 mm square is wound around an acrylic cylinder with a diameter of 50 mm with the layer of the silicone resin molded body on the outside and the long side of the rectangle along the circumference of the cylinder, no cracks or peeling of the silicone resin molded body occur.

[0066] Various additives can be added to the photo-curable silicone resin composition of the present invention within the scope not departing from the object of the present invention. As various additives, examples include organic / inorganic fillers, plasticizers, flame retardants, heat stabilizers, antioxidants, light stabilizers, ultraviolet absorbers, leveling agents, lubricity imparting agents, antistatic agents, mold release agents, foaming agents, nucleating agents, colorants, fluorescent brighteners, crosslinking agents, dispersion aids, resin components, and the like.

[0067] [Examples]

[0068] Hereinafter, examples of the present invention are shown. Furthermore, the reactive silicone resin used in the following examples was obtained by the method shown in the following synthesis examples.

[0069] [Synthesis Example 1]

[0070] In a reaction vessel equipped with a stirrer, a dropping funnel, and a thermometer, 40 ml of 2-propanol (IPA) as a solvent and 5% aqueous solution of tetramethylammonium hydroxide (TMAH (tetramethylammonium hydroxide) aqueous solution) as a basic catalyst were charged. 15 ml of IPA and 12.69 g of 3-methacryloxypropyltrimethoxysilane (MTMS: SZ-6030 manufactured by Toray Dow Corning Silicone Co., Ltd.) were added to the dropping funnel, and while stirring the reaction vessel, the IPA solution of MTMS was added dropwise at room temperature over 30 minutes. After the addition of MTMS was completed, it was stirred for 2 hours without heating. After stirring for 2 hours, the solvent was removed under reduced pressure and dissolved in 50 ml of toluene. The reaction solution was washed with saturated saline until it became neutral and then dehydrated with anhydrous magnesium sulfate. The anhydrous magnesium sulfate was filtered off and concentrated to obtain 25.8 g of a hydrolysis product (sesquisiloxane). The sesquisiloxane is a colorless viscous liquid soluble in various organic solvents.

[0071] Next, 20.65 g of the obtained sesquisiloxane, 82 ml of toluene, and 3.0 g of 10% aqueous TMAH solution were added to a reaction vessel equipped with a stirrer, Dean-Stark, and a cooling tube, and slowly heated to distill off water. Further heated to 130 °C, toluene was subjected to a recondensation reaction at the reflux temperature. The temperature of the reaction solution at this time was 108 °C. After stirring for 2 hours after toluene reflux, the reaction was terminated. The reaction solution was washed with saturated brine until it became neutral, and then dehydrated with anhydrous magnesium sulfate. The anhydrous magnesium sulfate was filtered off and concentrated to obtain 18.77 g of the target cage-type sesquisiloxane (mixture). The obtained cage-type sesquisiloxane (S1) is a colorless viscous liquid soluble in various organic solvents.

[0072] Mass spectrometry analysis of the reactants after the recondensation reaction by liquid chromatography separation confirmed that in the molecular structures of the structural formulas (5), (6), and (7), for the molecules with ammonium ions where R is methacryloyl, the composition ratio of T8:T10:T12:others is approximately 2:4:1:3, and it can be confirmed as a silicone resin mainly composed of a cage structure. Furthermore, T8, T10, and T12 correspond to the molecules where R is methacryloyl in the formulas (5), (6), and (7), respectively.

[0073] [Example 1]

[0074] 25 parts by mass of the cage-type silicone resin (S1) having methacryloyl groups on all silicon atoms in Synthesis Example 1 as the reactive silicone resin (A) component, 20 parts by mass of ethylene oxide 12 mol modified dipentaerythritol hexaacrylate (B1) (manufactured by Nippon Kayaku Co., Ltd., product name KAYARAD DPEA) as the polyfunctional epoxyalkane-modified unsaturated compound (B) component, 55 parts by mass of a 65:35 (mass ratio) mixture (C1) of dipentaerythritol hexaacrylate (Mw = 578.57, number of acrylate groups = 6, number of hydroxyl groups = 0) and dipentaerythritol pentaacrylate (Mw = 524.52, number of acrylate groups = 5, number of hydroxyl groups = 1) (manufactured by Nippon Kayaku Co., Ltd., product name KAYARAD DPHA) as the polyfunctional unsaturated compound (C) component, and 1-hydroxy-cyclohexyl-phenyl-ketone (D1) (manufactured by IGM, trade name Omnirad 184) as the active energy ray polymerization initiator (D) were mixed to obtain a photocurable silicone resin composition.

[0075] Next, the obtained photocurable silicone resin composition: 50 parts by mass, propylene glycol monomethyl ether as a diluting solvent: 50 parts by mass, and a fluorine-based surface conditioner (KY-1203 manufactured by Shin-Etsu Chemical Co., Ltd.): 1 part by mass are mixed. In the atmosphere, using a bar coater, the mixture is coated on the polymethyl methacrylate side of a composite plate (thickness 600 μm, length 10 cm, width 10 cm, C001 manufactured by Escarbosheet Co., Ltd.) containing polymethyl methacrylate / polycarbonate so that the dried film thickness becomes 10 μm, and it is dried at 80 °C for 5 minutes. Thereafter, in an oxygen environment, it is cured with a cumulative exposure dose of 2,800 mJ / cm 2 to obtain a laminate test piece in which a layer of the present silicone resin formed body is formed on the polymethyl methacrylate surface of the composite plate.

[0076] [Examples 2 to 14, Comparative Examples 1 to 5]

[0077] Except for using the raw materials and composition ratios described in Table 1, a photocurable silicone resin composition is obtained in the same order as in Example 1. Furthermore, other abbreviations in the table are as follows.

[0078] DGE-4A: Ethylene oxide 4-mole modified diglycerol tetraacrylate (B2) (number of acrylic acid groups = 4, number of ethylene oxide modifications = 4, manufactured by Kyoeisha Chemical Co., Ltd.)

[0079] M3130: Ethylene oxide 3-mole modified trimethylolpropane triacrylate (B3) (number of acrylic acid groups = 3, number of ethylene oxide modifications = 3, manufactured by MIWON Co., Ltd.)

[0080] M3190: Ethylene oxide 9-mole modified trimethylolpropane triacrylate (B4) (number of acrylic acid groups = 3, number of ethylene oxide modifications = 9, manufactured by MIWON Co., Ltd.)

[0081] M320: Propylene oxide 3-mole modified glycerol triacrylate (B5) (number of acrylic acid groups = 3, number of propylene oxide modifications = 3, manufactured by MIWON Co., Ltd.)

[0082] Light Acrylate PE-3A (C2): A 40:60 (mass ratio) mixture of pentaerythritol tetraacrylate (number of acrylic acid groups = 4, number of hydroxyl groups = 0) and pentaerythritol triacrylate (number of acrylic acid groups = 3, number of hydroxyl groups = 1) (manufactured by Kyoeisha Chemical Co., Ltd.)

[0083] Light Acrylate TMP-A (C'1): Trimethylolpropane triacrylate (number of acrylic acid groups = 3, number of hydroxyl groups = 0, manufactured by Kyoeisha Chemical Co., Ltd.)

[0084] [Evaluation]

[0085] The obtained laminate test pieces were used for the following evaluations. The evaluation results are shown in Tables 1 to 3.

[0086] [Pencil hardness]

[0087] According to JIS K 5600, using a Mitsubishi pencil UNI, the side surface of the silicone resin formed body of the laminate test piece was scraped at a load of 750 g and an angle of 45 degrees, and the hardness without damage was visually determined.

[0088] [Abrasion resistance]

[0089] Using #0000 steel wool, a reciprocating abrasion tester (Model: 30S, manufactured by HEIDON Corporation) was used to abrade the side surface of the silicone resin formed body of the laminate test piece under a load of 1.5 kg / cm 2 The scratches with a length of 1 mm or more were judged as scratches. The presence or absence of scratches was visually observed under a fluorescent lamp, and the number of scratches was evaluated according to the following criteria.

[0090] ◎: No scratches after 1000 reciprocations

[0091] 〇: No scratches after 300 reciprocations

[0092] △: Less than 10 scratches after 300 reciprocations

[0093] ×: 10 or more scratches after 300 reciprocations

[0094] [Flexural resistance]

[0095] The laminate test piece was cut into a square of 80 mm × 50 mm, and with the side of the silicone resin formed body on the outside, it was wound around an acrylic cylinder with a diameter of 50 mm in such a way that the long side of the rectangle was along the circumference of the cylinder, and the deformation or crack of the silicone resin formed body was visually observed.

[0096] ○: No cracks or peeling occurred

[0097] ×: Cracks or peeling occurred

[0098] [Table 1]

[0099]

[0100] [Table 2]

[0101]

[0102] [Table 3]

[0103]

Claims

1. A photocurable silicone resin composition, characterized in that Based on 100 parts by mass of the photocurable silicone resin composition, a reactive silicone resin (A), a polyfunctional epoxyalkane-modified unsaturated compound (B), and a polyfunctional unsaturated compound (C) are blended in a mass ratio of 1 to 50: 10 to 40: 10 to 80. The polyfunctional epoxyalkane-modified unsaturated compound (B) contains at least two -R in one molecule 3 -CR 4 an unsaturated group represented by =CH2 and also has an epoxyalkane modification site, where R 3 represents an -O-C(=O)- group, and R 4 represents a hydrogen atom or an alkyl group; The polyfunctional unsaturated compound (C) contains two or more of the above-mentioned unsaturated groups in one molecule and does not contain an epoxyalkane-modified moiety. The polyfunctional unsaturated compound (C) is a polyfunctional unsaturated compound as follows: containing at least two -R in the molecule 3 -CR 4 =CH2 represented unsaturated group, wherein, R 3 represents -O-C(=O)- group, R 4 represents a hydrogen atom or an alkyl group, and further, 20% by mass or more of the component (C) contains a hydroxyl group in 100% by mass The reactive silicone resin (A) is represented by the general formula (1), and the content of polyorganosilsesquioxane having a cage structure in the structural unit is 70% or more: [RSiO 3 / 2 n (1)​ In (1), R is an organic functional group having a (meth)acryloyl group, and n is 8, 10, or 12.

2. The photocurable silicone resin composition according to claim 1, wherein The polyfunctional epoxyalkane-modified unsaturated compound (B) is a polyfunctional epoxyalkane-modified unsaturated compound as follows: it contains at least two -R groups in the molecule 3 -CR 4 =CH2 groups representing unsaturated groups, where R 3 represents an -O-C(=O)- group, R 4 represents a hydrogen atom or an alkyl group, the epoxyalkane modification site is ethylene oxide or propylene oxide, and at least one epoxyalkane modification site is contained relative to one unsaturated group.

3. The photocurable silicone resin composition according to claim 1 or 2, wherein It further contains an active energy ray polymerization initiator (D).

4. A photocurable silicone resin molded article is obtained by subjecting the photocurable silicone resin composition according to any one of claims 1 to 3 to radical copolymerization and curing the same.

5. A photocurable silicone resin laminate is obtained by coating the photocurable silicone resin composition according to any one of claims 1 to 3 on a substrate, subjecting the same to radical copolymerization, and curing the same.

6. A method for manufacturing a photocurable silicone resin molded body, characterized in that, Under the atmosphere, an active energy ray is irradiated to the photocurable silicone resin composition according to any one of claims 1 to 3, and radical copolymerization is carried out to form a silicone resin molded article.

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