JP2012184371A - Silicone resin composition and its compact - Google Patents

Abstract

[PROBLEMS] To provide a silicone resin composition which can be easily molded into a film or a sheet and can provide a silicone resin molded article having a pencil hardness of 5H or more, which has a significantly improved surface hardness as compared with the prior art, and a silicone resin molding obtained therefrom. Provide the body.
A silicone resin (A) comprising a polyorganosilsesquioxane represented by the general formula [RSiO _3/2 ] _n and having a cage structure in the structural unit as a main component, and a predetermined polyfunctional unsaturation The compound (B) can be radically copolymerized with the silicone resin, and is a component composed of an unsaturated compound other than the polyfunctional unsaturated compound (B), and 80 to 100% by weight of the compound is a predetermined alicyclic ring. This is a silicone resin composition comprising an unsaturated compound component (C), which is an unsaturated compound, and a compound (D) having an unsaturated group at the end and having a urethane bond, and this is a radical copolymer It is the silicone resin molding obtained by making it.
[Selection figure] None

Description

  The present invention relates to a silicone resin composition and a molded article thereof, and more particularly, a silicone resin composition capable of obtaining a molded article having high surface hardness, and a three-dimensional crosslinked product obtained by radical polymerization of the silicone resin composition. The present invention relates to a silicone resin molded body.

  Since inorganic glass has high transparency, heat resistance, and dimensional stability, it has been used in a wider range of industrial fields since long ago as a structure that transmits visible light while separating spaces but does not hinder visibility. . Although it is an inorganic glass having such excellent characteristics, it has two major drawbacks: its specific gravity is as heavy as 2.5 or more, and it is weak against impact and easily broken. In particular, as a result of recent progress in downsizing such as light weight and thinning in all industrial fields, users are increasingly demanding improvement of the above defects.

  One of the applications where the replacement of inorganic glass is strongly demanded and the replacement is progressing is LCD protective plates for LCDs such as mobile phones and tablet PCs. The LCD front protective plate is a member arranged on the outermost surface with an air layer or an optical adhesive interposed between the front surface of the LCD. In recent years, the structure that the LCD front protective plate is exposed to the outside, such as slide type and bar type, is becoming mainstream in mobile phones, so if there is no surface hardness to some extent, the surface of the LCD front protective plate will be There is a problem that the LCD is scratched and the LCD becomes difficult to see. Therefore, there is a demand for a material that is resistant to external impacts and has high surface hardness and is hardly damaged.

  As a material that meets such demands from the industry, there are high expectations for transparent thermoplastic and thermosetting plastics. Here, examples of the transparent thermoplastic plastic include PMMA (polymethyl methacrylate) and PC (polycarbonate). Among them, PMMA is also called organic glass, and has attracted attention as a material that has excellent transparency and overcomes the two major drawbacks of glass. However, these transparent plastics are remarkably inferior in surface hardness as compared with inorganic glass, and in use, a treatment such as providing a hard coat layer on the surface is required. However, the normal hard coat treatment increases the surface hardness by about 2 to 4 H in terms of pencil hardness, and is insufficient as an LCD front protective plate. Further, this hard coat layer has a problem that it peels off as it is used and deteriorates with time.

  On the other hand, as a transparent thermosetting plastic, an epoxy resin, a curable (meth) acrylate resin, and the like can be exemplified, and these have a surface hardness higher than that of the above thermoplastic plastic depending on the composition. However, if the surface hardness of the epoxy resin or curable (meth) acrylate resin is sufficiently high, the curing shrinkage rate becomes extremely large, and the material becomes brittle and has poor moldability, making it difficult to form a sheet or film.

  On the other hand, as an example of a curable resin, polyorganosilsesquioxane, which is excellent in terms of heat resistance, weather resistance, and water resistance, among which (meth) acrylate trichlorosilane is hydrolyzed in an organic solvent. (Meth) acrylate trihydroxysilane, and this hydrolyzed product is heated in a solvent free of water using an alkaline rearrangement and condensation catalyst, and is dehydrated and condensation polymerized to obtain a vertical octa (meth) acrylate silsesquioxy Sun, a silicone resin molded article obtained by blending the octagonal (meth) acrylate silsesquioxane and an unsaturated compound capable of radical copolymerization at a specific ratio is disclosed in Japanese Patent No. 4409997 (Patent Document 1) Is disclosed.

Japanese Patent No. 4409397

  The silicone resin molded body shown in the example of Patent Document 1 is easy to form a film or a sheet, and has a surface hardness of about 3H, which has a pencil hardness significantly higher than that of acrylic without being subjected to a hard coat treatment. However, it is desirable to further improve the surface hardness for use in applications such as an LCD front protective plate as an alternative to glass.

  Accordingly, an object of the present invention is to provide a silicone resin composition that can be easily molded into a film or a sheet, and can provide a silicone resin molded article having a pencil hardness of 5H or more, which is significantly improved in surface hardness as compared with the prior art. is there.

  Therefore, as a result of intensive investigations on the combination of radically polymerizable unsaturated compounds in the composition of the silicone resin composition in the above-mentioned silicone resin molded article, the present inventors have found that the above problems can be solved, Completed the invention.

（一般式（２）中、Ｚは（2a）又は（2b）で表される何れかの基を示し、Ｒ⁵は水素又はメチル基を示す） That is, the present invention relates to the general formula (1),
[RSiO _3/2 ] _n (1)
(However, R is an organic functional group having a (meth) acryloyl group represented by CH ₂ = CR ₁ —COO— (CH ₂ ) _m —, m is an integer of 1 to 3, and R ₁ is a hydrogen atom. Or a methyl group. N is 8, 10 or 12), and a silicone resin (A) mainly comprising polyorganosilsesquioxane having a cage structure in the structural unit, and in the molecule —R ³ —CR ⁴ ═CH ₂ or —CR ⁴ ═CH ₂ (wherein R ³ represents an alkylene group having 1 to 6 carbon atoms, an alkylidene group having 1 to 6 carbon atoms or an —OCO— group, and R ⁴ represents A polyfunctional unsaturated compound (B) containing at least three unsaturated groups represented by hydrogen or a methyl group) and —R ³ —CR ⁴ ═CH ₂ or —CR ⁴ ═CH ₂ (R ³ and R ⁴ are as described above) and can be radically copolymerized with the silicone resin. A component comprising an unsaturated compound other than the polyfunctional unsaturated compound (B), wherein 80 to 100% by weight is an alicyclic unsaturated compound represented by the following general formula (2) The saturated compound component (C) and the compound (D) having an unsaturated group at the terminal and having a urethane bond are represented by A: B: C: D = 5 to 80: 1 to 50:10 to 80: A silicone resin composition characterized in that it is blended at a weight ratio (%) of 1 to 60 and the weight ratio of the silicone resin (A) and the polyfunctional unsaturated compound (B) is 30% or more. It is.

(In general formula (2), Z represents any group represented by (2a) or (2b), and R ⁵ represents hydrogen or a methyl group)

Moreover, this invention is a silicone resin copolymer or a molded object obtained by carrying out radical copolymerization of the said silicone resin composition. The silicone resin molded body preferably satisfies the following conditions (A) to (E).
(B) Pencil hardness of 5H or more, preferably 7H or more (b) Glass transition temperature is 300 ° C. or more (C) Linear expansion coefficient is 70 ppm / K or less (d) Visible light transmittance of 400 to 800 nm wavelength is 85% or more (E) Birefringence is 1.0 nm or less

  Furthermore, the present invention is a method for producing a silicone resin molded article, wherein the silicone resin composition is radically copolymerized by heating or irradiation with energy rays.

The present invention will be further described below.
The silicone resin composition of the present invention comprises A) a silicone resin represented by the general formula (1) (hereinafter also referred to as the present silicone resin), and B) -R ³ -CR ⁴ = CH ₂ or -CR in the molecule. ⁴ ═CH ₂ (wherein R ³ represents an alkylene group having 1 to 6 carbon atoms, an alkylidene group having 1 to 6 carbon atoms, or —OCO— group, and R ⁴ represents hydrogen or a methyl group). Functional unsaturated compound (hereinafter also referred to as the present polyfunctional unsaturated compound), C) -R ³ -CR ⁴ = CH ₂ or -CR ⁴ = CH _{2 in the} molecule (R ³ and R ⁴ are as described above. And is a component composed of an unsaturated compound other than the polyfunctional unsaturated compound (B), which is capable of being radically copolymerized with the silicone resin, and having 80 to 100 weights thereof % Is an alicyclic unsaturated compound represented by the general formula (2) (Hereinafter also referred to as the unsaturated compound component), and D) a compound having an unsaturated group at the terminal and having a urethane bond (hereinafter also referred to as the oligomer) as an essential component. The main component of the resin component (excluding solvent and filler, including polymerizable component). Molded articles such as films can be obtained by radical copolymerization of the silicone resin composition of the present invention. The molded article of the present invention can be obtained by molding and curing this silicone resin composition or molding this silicone resin copolymer. The silicone resin copolymer of the present invention is a crosslinked polymer, and in this case, a molding and curing method similar to that of a thermosetting resin can be adopted.

A) This silicone resin used in the present invention is a polyorganosilsesquioxane represented by the above general formula (1) and having a cage structure in a structural unit (also called caged polyorganosilsesquioxane). The main component.
In general formula (1), R is an organic functional group having a (meth) acryloyl group, and is an organic functional group represented by the following general formula (4), and n is 8, 10 or 12. In General Formula (4), m is an integer of 1 to 3, and R ₁ is a hydrogen atom or a methyl group. In general formula (4) is _{CH 2 = CR 1 -COO- (CH} 2) m - can also be expressed as.

A) This silicone resin has a reactive functional group on the silicon atom in the molecule. Specific structures of the cage polyorganosilsesquioxane in which n in the general formula (1) is 8, 10, 12 are as shown in the following structural formulas (5), (6) and (7). An example is a saddle type structure. In addition, R in the following formula represents the same as R in the general formula (1).

This silicone resin can be produced by the method described in Japanese Patent No. 4256756. For example, a silicon compound represented by RSiX ₃ is subjected to a hydrolysis reaction in the presence of a polar solvent and a basic catalyst and partially condensed, and the obtained hydrolysis product is further recycled in the presence of a nonpolar solvent and a basic catalyst. It can be obtained by condensation. Here, R is a group represented by the general formula (4), and X represents a hydrolyzable group. Specific examples of preferred R include a 3-methacryloxypropyl group, a methacryloxymethyl group, and a 3-acryloxypropyl group.

  The hydrolyzable group X is not particularly limited as long as it is a hydrolyzable group, and examples thereof include an alkoxy group and an acetoxy group, but an alkoxyl group is preferable. Examples of the alkoxyl group include methoxy group, ethoxy group, n- and i-propoxy group, n-, i- and t-butoxy group. A methoxy group is preferable because of its high reactivity.

Among the silicon compounds represented by RSiX ₃ , preferable compounds are methacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxylane, 3-methacryloxypropyltrichlorosilane, 3-methacryloxypropyltrimethoxysilane, 3- Examples include methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-acryloxypropyltrichlorosilane. Among these, it is preferable to use 3-methacryloxypropyltrimethoxysilane, which is easily available.

  Basic catalysts used in the hydrolysis reaction include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, cesium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, benzyl Examples thereof include ammonium hydroxide salts such as trimethylammonium hydroxide and benzyltriethylammonium hydroxide. Among these, tetramethylammonium hydroxide is preferably used because of its high catalytic activity. The basic catalyst is usually used as an aqueous solution.

  About hydrolysis reaction conditions, 0-60 degreeC is preferable and reaction temperature is more preferable 20-40 degreeC. When 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 long reaction time. On the other hand, when the temperature is higher than 60 ° C., the reaction rate is too high, so that a complicated condensation reaction proceeds, and as a result, a high molecular weight of the hydrolysis product is promoted. The reaction time is preferably 2 hours or more. If the reaction time is less than 2 hours, the hydrolysis reaction does not proceed sufficiently and the hydrolyzable group remains in an unreacted state.

  In the hydrolysis reaction, the presence of water is essential, but this can be supplied from an aqueous solution of a basic catalyst or may be added as water separately. The amount of water is not less than an amount sufficient to hydrolyze the hydrolyzable group, preferably 1.0 to 1.5 times the theoretical amount. Moreover, it is necessary to use an organic polar solvent at the time of hydrolysis, and alcohol, such as methanol, ethanol, 2-propanol, or another organic polar solvent can be used as an organic polar solvent. Preferred are lower alcohols having 1 to 6 carbon atoms that are soluble in water, and 2-propanol is more preferred. Use of a nonpolar solvent is not preferable because the reaction system is not uniform and the hydrolysis reaction does not proceed sufficiently and unreacted alkoxyl groups remain.

  After completion of the hydrolysis reaction, water or a water-containing reaction solvent is separated. Separation of water or the water-containing reaction solvent can employ means such as evaporation under reduced pressure. In order to sufficiently remove moisture and other impurities, a non-polar solvent is added to dissolve the hydrolysis reaction product, this solution is washed with brine, and then dried with a desiccant such as anhydrous magnesium sulfate. It is possible to adopt a means such as If the nonpolar solvent is separated by means such as evaporation, the hydrolysis reaction product can be recovered. However, if the nonpolar solvent can be used as the nonpolar solvent used in the next reaction, it is separated. do not have to.

  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 having a number average molecular weight of 1400 to 5000. Although the hydrolysis product varies depending on the reaction conditions, it becomes an oligomer having a number average molecular weight of 1400 to 3000, and most of the hydrolyzable group X, preferably almost all, is substituted with OH groups, and most of the OH groups, Preferably 95% or more is condensed. As for the structure of the hydrolysis product, there are several types of cage-type, ladder-type, and random-type silsesquioxanes, and the proportion of the complete cage-type structure is small even for compounds that have a cage-type structure. Mainly an incomplete cage structure with some open. Therefore, the hydrolysis product obtained by this hydrolysis is further heated in an organic solvent in the presence of a basic catalyst to condense the siloxane bond (referred to as recondensation), thereby producing a silsesquioxy having a cage structure. Selectively produce sun.

  After separating water or the water-containing reaction solvent, a recondensation reaction is performed in the presence of a nonpolar solvent and a basic catalyst. Regarding the reaction conditions for the recondensation reaction, the reaction temperature is preferably in the range of 100 to 200 ° C, more preferably 110 to 140 ° C. On the other hand, if the reaction temperature is too low, sufficient driving force cannot be obtained to cause the recondensation reaction, and the reaction does not proceed. If the reaction temperature is too high, the (meth) acryloyl group may cause a self-polymerization reaction. Therefore, it is necessary to suppress the reaction temperature or add a polymerization inhibitor or the like. The reaction time is preferably 2 to 12 hours. The amount of the nonpolar solvent used is preferably an amount sufficient to dissolve the hydrolysis reaction product, and the amount of the basic catalyst used is in the range of 0.1 to 10 wt% with respect to the hydrolysis reaction product.

  Any nonpolar solvent may be used as long as it is insoluble or hardly soluble in water, but a hydrocarbon solvent is preferred. Such hydrocarbon solvents include nonpolar solvents having a low boiling point such as toluene, benzene, and xylene. Of these, it is preferable to use toluene. As the basic catalyst, a basic catalyst used in a hydrolysis reaction can be used. Alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and cesium hydroxide, tetramer ammonium ammonium hydroxide, tetraethyl ammonium hydroxide Ammonium hydroxide salts such as tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, and benzyltriethylammonium hydroxide, but a catalyst soluble in a nonpolar solvent such as tetraalkylammonium is preferred.

  The hydrolysis product used for recondensation is preferably washed, dehydrated and concentrated, but can be used without washing and dehydration. In this reaction, water may be present, but it is not necessary to add it positively, and it is preferable that the water is brought to the extent of water brought from the basic catalyst solution. If the hydrolysis product has not been sufficiently hydrolyzed, it requires more water than the theoretical amount necessary to hydrolyze the remaining hydrolyzable groups, but usually the hydrolysis reaction is sufficient. To be done. After the recondensation reaction, the catalyst is washed away with water and concentrated to obtain a silsesquioxane mixture.

  The silsesquioxane thus obtained varies depending on the reaction conditions and the state of the hydrolysis product, but the constituent components are more than 70% of a plurality of cage silsesquioxanes, and the remainder is a ladder type. It is expected to be a random cross-linked silsesquioxane. Since these are difficult to separate and require a lot of labor, in the present invention, silsesquioxane containing 70% or more of the cage silsesquioxane represented by the general formula (1) is used as the silicone resin of the present invention. To do. In addition, there is no difference in the effect acquired if cage-type silsesquioxane content is 70% or more. The components of the multiple types of cage silsesquioxanes are 20 to 40% T8 represented by the general formula (5), 40 to 50% T10 represented by the general formula (6), and other components are general. It is T12 represented by Formula (7). T8 can be separated as a needle-like crystal by leaving the siloxane mixture at 20 ° C. or lower.

  The silicone resin used in the present invention may be a mixture of T8 to T12, or may be one obtained by separating or concentrating 1 or 2 such as T8. Further, the silicone resin used in the present invention is not limited to the silicone resin obtained by the above production method.

In the silicone resin composition of the present invention, A) a compound used together with the silicone resin, D) a compound having a urethane bond (present oligomer) is a compound having an unsaturated group at the terminal and having a urethane bond, Preferably, the molecule contains at least one unsaturated group represented by —R ³ —CR ⁴ ═CH ₂ or —CR ⁴ ═CH ₂ and has a number average molecular weight of 2500 or more capable of radical copolymerization with the silicone resin. It is an oligomer having a urethane bond. Here, R ³ represents an alkylene group, an alkylidene group, or an —OCO— group, and the alkylene group and alkylidene group are preferably a lower alkylene group having 1 to 6 carbon atoms and an alkylidene group. R ⁴ represents hydrogen or an alkyl group, preferably hydrogen or a methyl group. Preferable unsaturated groups include at least one selected from the group consisting of acryloyl group, methacryloyl group, allyl group and vinyl group.

  This oligomer can be manufactured by the method generally used conventionally. That is, a method of synthesizing from a polyol, a polyisocyanate, and a compound having a polymerizable unsaturated group and a hydroxyl group at the terminal. In that case, the urethane acrylate used for the resin composition of this invention can be obtained by adjusting suitably the molecular weight of a raw material substance, or the molar ratio at the time of reaction.

  Examples of the polyol include polyester polyols obtained by polycondensation of polybasic acids and polyhydric alcohols, polyester polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone and γ-valerolactone, ethylene oxide, propylene oxide. , Alkylene oxides such as butylene oxide, polymers of cyclic ethers such as tetrahydrofuran and alkyl-substituted tetrahydrofuran, or polyether polyols that are copolymers of two or more of these.

  Examples of the polyisocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hydrogenated 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, and hydrogenated xylylene diene. Isocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate, transcyclohexane 1,4-diisocyanate, lysine diisocyanate, tetramethylxylene diisocyanate, lysine ester triisocyanate, 1,6,11 -Undecane triisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane, 1,3,6-hexa Examples include methylene triisocyanate, bicycloheptane triisocyanate, trimethylhexamethylene diisocyanate, dicyclopentadiene diisocyanate, and norbornene diisocyanate.

Examples of the compound having a polymerizable unsaturated group and a hydroxyl group at the terminal include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (Meth) acryloyloxyethyl-2-hydroxyethylphthalic acid, pentaerythritol tri (meth) acrylate, 3-acryloyloxyglycerin mono (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-1- (meta ) Acryloxy-3- (meth) acryloxypropane, glycerin di (meth) acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, poly ε-caprolactone mono (meth) actyl Rate, 4-hydroxybutyl (meth) acrylate, .epsilon.-caprolactone mono (meth) acrylate, various types of epoxy acrylate.
In addition, this oligomer can use what is marketed, for example, the urethane acrylate oligomer UF-8001 (number average molecular weight: 2600) and UF-503 (number average molecular weight: 3800) by Kyoeisha Chemical Co., Ltd. ) And urethane acrylate oligomer UA-122P (number average molecular weight: 1100) manufactured by Shin-Nakamura Chemical Co., Ltd. is preferably used.

Examples of the polyfunctional unsaturated compound B) used in the silicone resin composition of the present invention include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate and the like. In addition to these, a terminal hydroxy group of a skeleton obtained by modifying a part or all of the hydroxy groups of pentaerythritol and dipentaerythritol with glycol such as ethylene or isopropylene, γ-butyrolactone, or the like, and -R ³ -CR ⁴ = CH ₂ or -CR ⁴ = CH ₂ (where, R ³ is an alkylene group, an alkylidene group or a -OCO- group, R ⁴ represents hydrogen or an alkyl group) with an unsaturated group represented by Modified compounds and the like can also be used. These polyfunctional unsaturated compounds may be used alone or in combination of two or more.

  The C) unsaturated compound component used in the silicone resin composition of the present invention comprises D) a compound having a urethane bond and B) an unsaturated compound other than the polyfunctional unsaturated compound, and A) the present compound. It can be copolymerized with a silicone resin. The unsaturated compound component is not limited as long as the above conditions are satisfied, but the alicyclic unsaturated compound represented by the general formula (2) is contained in an amount of 80 to 100% by weight. By including such a C) unsaturated compound component, according to the silicone resin composition of this invention, it can be set as a low water absorption molded object.

In the alicyclic unsaturated compound represented by the general formula (2), as a specific compound in the case where Z is a group represented by the formula (2a), pentacyclo [6.5 in which R ⁵ is hydrogen. 1.1 ^3,6 . 0 ^2,7 . 0 ^9,13] Specific compounds of case pentadecane dimethylol diacrylate, Z is a group represented by the formula (2b), dicyclopentanyl diacrylate R ⁵ is hydrogen (or tricyclo [ 5.2.1.0 ^2,6 ] decane dimethylol diacrylate).

  Moreover, a reactive monofunctional and bifunctional monomer is mentioned as another component which can be used together with the alicyclic unsaturated compound represented by General formula (2). Reactive monofunctional monomers include styrene, vinyl acetate, N-vinyl pyrrolidone, butyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-decyl acrylate, isobornyl acrylate, dicyclopentenyloxyethyl Examples include acrylate, phenoxyethyl acrylate, trifluoroethyl methacrylate, and the like. Examples of reactive bifunctional monomers include tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol A diglycidyl ether diacrylate, tetraethylene glycol diacrylate, and hydroxypivalate neopentyl glycol diacrylate. Can do. Other components that can be used in combination with the alicyclic unsaturated compound represented by the general formula (2) can be used in a proportion of less than 20% with respect to the C) unsaturated compound component. If blended in an amount of 20% or more, the crosslinking density and the water absorption rate tend to decrease, which is not preferable.

  In the present invention, various reactive oligomers and monomers other than the above-mentioned A), B), C) and D) can also be blended as a minor component as an unsaturated compound. These reactive oligomers and monomers may be used alone or in combination of two or more.

  The silicone resin composition of the present invention comprises A) the present silicone resin, B) the present polyfunctional unsaturated compound, C) the present unsaturated compound component, and D) the present oligomer as the main components. The mixing ratio (weight ratio) is in the range of 5-80: 1 to 50: 10-80: 1-60, but preferably in the range of 5-60: 1-20: 10-80: 10-50. It is. A) If the silicone resin ratio is less than 5%, physical properties such as heat resistance, transparency and water absorption of the molded article after curing are unfavorable. Moreover, since the viscosity of a composition will increase when this silicone resin ratio exceeds 80%, manufacture of a molded object becomes difficult, it is unpreferable too. B) If the ratio of the polyfunctional unsaturated compound is less than 5%, the crosslinking density is lowered and the surface hardness is lowered. On the other hand, if it exceeds 50%, deformation due to shrinkage at the time of curing becomes remarkably large, which makes it difficult to produce a film or sheet form.

  Moreover, it is preferable that the ratio which combined A) this silicone resin and B) polyfunctional unsaturated compound is 30% or more of the whole. If it is less than 30% of the total, the surface hardness represented by the pencil hardness is remarkably lowered, which is not preferable.

  Moreover, low hygroscopicity can be provided to the copolymer obtained by mix | blending 10% or more of C) an unsaturated compound component. Further, D) By adding this oligomer in the range of 1 to 60%, the film or sheet can be provided with flexibility, and can be formed into a roll with good winding properties. When the ratio exceeds 60%, A) the compatibility with the silicone resin is poor and a uniform resin composition cannot be obtained, which is not preferable.

  The silicone resin composition of this invention can obtain a silicone resin copolymer by radical copolymerizing this. Various additives can be added to the silicone resin composition of the present invention for the purpose of improving the physical properties of the silicone resin copolymer or promoting radical copolymerization. Examples of the additive that accelerates the reaction include a thermal polymerization initiator, a thermal polymerization accelerator, a photopolymerization initiator, a photoinitiation assistant, and a sharpening agent. When a photopolymerization initiator or a thermal polymerization initiator is blended, the addition amount is preferably in the range of 0.1 to 5 parts by weight with respect to 100 parts by weight of the total of the silicone resin and the unsaturated compound. More preferably, it is in the range of 1 to 3 parts by weight. If this addition amount is less than 0.1 parts by weight, curing will be insufficient and the strength and rigidity of the resulting molded product will be low, while if it exceeds 5 parts by weight, problems such as coloring of the molded product may occur. is there.

  As the photopolymerization initiator used when the silicone resin composition is used as a photocurable composition, compounds such as acetophenone-based, benzoin-based, benzophenone-based, thioxanthone-based, and acylphosphine oxide-based compounds can be preferably used. . Specifically, trichloroacetophenone, diethoxyacetophenone, 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4-methylthiophenyl) -2 -Morpholinopropan-1-one, benzoin methyl ether, benzyldimethyl ketal, benzophenone, thioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, methylphenylglyoxylate, camphorquinone, benzyl, anthraquinone, Michler's ketone, etc. It can be illustrated. Moreover, the photoinitiator adjuvant and the sharpening agent which show an effect in combination with a photoinitiator can also be used together.

  Various additives can be added to the silicone resin composition of the present invention within a range not departing from the object of the present invention. Various additives include organic / inorganic fillers, plasticizers, flame retardants, heat stabilizers, antioxidants, light stabilizers, UV absorbers, lubricants, antistatic agents, mold release agents, foaming agents, nucleating agents, colorants, Crosslinking agents, dispersion aids, resin components and the like can be exemplified.

  A silicone resin copolymer can be obtained by radical copolymerization of the silicone resin composition of the present invention. In addition, the silicone resin composition can be obtained by radically copolymerizing the silicone resin composition into a predetermined shape. A molded body can be obtained. When the resulting silicone resin copolymer is thermoplastic, various molding methods can be employed, but when the number of reactive substituents or unsaturated groups per molecule exceeds 1.0, three-dimensional crosslinking is performed. Since it becomes the copolymer which has a structure, shaping | molding hardening is employ | adopted normally. Therefore, radical copolymerization is also called curing. For radical copolymerization, heating or irradiation with an energy beam such as an electron beam or an ultraviolet ray is suitable.

  The silicone resin copolymer of the present invention can be produced by curing a silicone resin composition containing a radical polymerization initiator by heating or light irradiation. When a copolymer (molded article) is produced by heating, the molding temperature can be selected from a wide range from room temperature to around 200 ° C., depending on the selection of the thermal polymerization initiator and accelerator. In this case, a silicone resin molded body having a desired shape can be obtained by polymerization and curing in a mold or on a steel belt.

  Moreover, when manufacturing a copolymer (molded object) by light irradiation, a molded object can be obtained by irradiating ultraviolet rays with a wavelength of 10 to 400 nm or visible rays with a wavelength of 400 to 700 nm. The wavelength of the light to be used is not particularly limited, but near ultraviolet light having a wavelength of 200 to 400 nm is particularly preferably used. As a lamp used as an ultraviolet ray generation source, a low-pressure mercury lamp (output: 0.4 to 4 W / cm), a high-pressure mercury lamp (40 to 160 W / cm), an ultra-high pressure mercury lamp (173 to 435 W / cm), a metal halide lamp (80-160 W / cm), a pulse xenon lamp (80-120 W / cm), an electrodeless discharge lamp (80-120 W / cm), etc. can be illustrated. Each of these ultraviolet lamps is characterized by its spectral distribution, and is therefore selected according to the type of photoinitiator used.

  As a method for obtaining a silicone resin copolymer (molded product) by light irradiation, for example, it is injected into a mold having an arbitrary cavity shape and made of a transparent material such as quartz glass, and ultraviolet rays are emitted from the above ultraviolet lamp. The method of producing a molded body having a desired shape by performing polymerization and curing by irradiating the mold, and when not using a mold, for example, a doctor blade or a roll on a moving steel belt The method of manufacturing a sheet-like molded object etc. can be illustrated by apply | coating the silicone resin composition of this invention using the coater of this, and carrying out polymerization hardening with said ultraviolet lamp.

  The silicone resin copolymer (molded product) of the present invention thus obtained exhibits extremely high surface hardness as a resin having a pencil hardness of 5H or more. Further, the glass transition temperature measured by a dynamic thermomechanical analyzer does not show a glass transition temperature lower than 300 ° C., and the substrate can be processed at a high temperature in thin film deposition or the like. Further, when the linear expansion coefficient is 70 ppm / K or less, more preferably 65 ppm / K or less, the difference in thermal expansion from the peripheral members becomes small, which is advantageous for dimensional stability. Further, the transmittance of visible light having a wavelength of 400 to 800 nm is 85% or more, more preferably 90% or more, and birefringence is 1.0 nm or less, more preferably 0.8 nm or less. When applied to a display member such as a protective plate, a clear image without distortion can be obtained.

  According to the silicone resin composition of the present invention, a molded product having high surface hardness, high heat resistance, high transparency, and high dimensional stability can be obtained. For example, an LCD front protective plate, a touch panel substrate, It can be used for various applications such as optical applications such as flat panel display substrates, lenses, optical disks and optical fibers, and window materials for various transport machines and houses. The molded body is a transparent member having a light weight and high impact strength, and has a wide range of use as a glass substitute material and has high industrial utility value.

  Examples of the present invention will be described below. In addition, the silicone resin used for the following Example was obtained by the method shown to the following synthesis examples.

[Synthesis Example 1]
A reaction vessel equipped with a stirrer, a dropping funnel and a thermometer was charged with 40 ml of 2-propanol (IPA) as a solvent and 5% tetramethylammonium hydroxide aqueous solution (TMAH aqueous solution) as a basic catalyst. In a dropping funnel, 15 ml of IPA and 12.69 g of 3-methacryloxypropyltrimethoxysilane (MTMS: SZ-6300 manufactured by Toray Dow Corning Silicone Co., Ltd.) were added, and the IPA solution of MTMS was added at room temperature while stirring the reaction vessel. It was added dropwise over 30 minutes. After completion of the MTMS addition, the mixture 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 brine until neutral, and then dehydrated with anhydrous magnesium sulfate. 8.6 g of hydrolysis product (silsesquioxane) was obtained by filtering off anhydrous magnesium sulfate and concentrating. This silsesquioxane was a colorless viscous liquid soluble in various organic solvents.

  Next, 20.65 g of the silsesquioxane obtained above, 82 ml of toluene, and 3.0 g of 10% TMAH aqueous solution were placed in a reaction vessel equipped with a stirrer, a Dinsterk, and a cooling tube, and the water was gradually heated to maintain the water. Left. Further, the mixture was heated to 130 ° C., and toluene was recondensed at the reflux temperature. The temperature of the reaction solution at this time was 108 ° C. After stirring for 2 hours after refluxing toluene, the reaction was terminated. The reaction solution was washed with saturated brine until 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 basket-type silsesquioxane (mixture). The resulting cage-type silsesquioxane was a colorless viscous liquid soluble in various organic solvents.

  Mass spectrometry after separation by liquid chromatography of the reaction product after the recondensation reaction confirmed that molecular ions with ammonium ions in the molecular structures of the above structural formulas (5), (6) and (7) were confirmed. The ratio of T8: T10: T12 and others was about 2: 4: 1: 3, and it was confirmed that the silicone resin was mainly composed of a cage structure.

[Example 1]
Vertical silicone resin having methacryloyl groups obtained in Synthesis Example 1 on all silicon atoms: 25 parts by weight, dipentaerythritol hexaacrylate: 40 parts by weight, dicyclopentanyl diacrylate: 30 parts by weight, urethane acrylate Oligomer 1: 5 parts by weight and 1-hydroxycyclohexyl phenyl ketone: 2.5 parts by weight as a photopolymerization initiator were mixed to obtain a transparent silicone resin composition.

Next, it is cast (cast) to a thickness of 0.2 mm using a roll coater, and cured with a cumulative exposure amount of 2000 mJ / cm ² using a 30 W / cm high-pressure mercury lamp, to a predetermined thickness. A sheet-like silicone resin molded product was obtained.

[Examples 2 to 4 and Comparative Examples 1 to 4]
A resin molded body was obtained in the same manner as in Example 1 except that the blending composition was changed to the weight ratio shown in Table 1. Table 2 summarizes the physical property values of the obtained molded body.

Abbreviations in the table are as follows.
A: Compound B obtained in Synthesis Example 1 Dipentaerythritol hexaacrylate C: Trimethylolpropane triacrylate
D: Dicyclopentanyl diacrylate (Kyoeisha Chemical Co., Ltd. light acrylate DCP-A (in general formula (2), Z is (a2) and R is H))
E: Urethane acrylate oligomer 1 (UF-503 manufactured by Kyoeisha Chemical Co., Ltd .: number average molecular weight about 3800)
F: Urethane acrylate oligomer 2 (Kyoeisha Chemical Co., Ltd. UF-8001: Number average molecular weight about 2600)
G: Urethane acrylate oligomer 3 (UA-122P manufactured by Shin-Nakamura Chemical Co., Ltd .: number average molecular weight of about 1100)
H: 1-hydroxycyclohexyl phenyl ketone (polymerization initiator)

Various characteristics were evaluated by the following methods.
1) Pencil hardness: (reference standard JIS K 5600): sample thickness 0.2 mm)
2) Glass transition temperature: Dynamic thermomechanical analysis, heating rate 5 ° C / min, chuck distance 10mm
3) Linear expansion coefficient: Thermomechanical analysis method, heating rate 5 ° C / min, compression load 0.1N
4) Total light transmittance (reference standard JIS K 7361-1): sample thickness 0.2 mm)
5) Birefringence: Spectroscopic ellipsometry: Sample thickness 0.2mm

Claims (5)

Formula (1),
[RSiO _3/2 ] _n (1)
(However, R is an organic functional group having a (meth) acryloyl group represented by CH ₂ = CR ₁ —COO— (CH ₂ ) _m —, m is an integer of 1 to 3, and R ₁ is a hydrogen atom. Or a methyl group. N is 8, 10 or 12), and a silicone resin (A) mainly comprising polyorganosilsesquioxane having a cage structure in the structural unit, and in the molecule —R ³ —CR ⁴ ═CH ₂ or —CR ⁴ ═CH ₂ (wherein R ³ represents an alkylene group having 1 to 6 carbon atoms, an alkylidene group having 1 to 6 carbon atoms or an —OCO— group, and R ⁴ represents A polyfunctional unsaturated compound (B) containing at least three unsaturated groups represented by hydrogen or a methyl group) and —R ³ —CR ⁴ ═CH ₂ or —CR ⁴ ═CH ₂ (R ³ and R ⁴ are as described above) and can be radically copolymerized with the silicone resin. A component comprising an unsaturated compound other than the polyfunctional unsaturated compound (B), wherein 80 to 100% by weight is an alicyclic unsaturated compound represented by the following general formula (2) The saturated compound component (C) and the compound (D) having an unsaturated group at the terminal and having a urethane bond are represented by A: B: C: D = 5 to 80: 1 to 50:10 to 80: A silicone resin composition characterized in that it is blended at a weight ratio (%) of 1 to 60 and the weight ratio of the silicone resin (A) and the polyfunctional unsaturated compound (B) is 30% or more. .

(In general formula (2), Z represents any group represented by (2a) or (2b), and R ⁵ represents hydrogen or a methyl group) Terminus have an unsaturated group, and, -R terminated compound having a urethane bond (D) is unsaturated group ³ -CR ⁴ = CH ₂ or -CR ⁴ = CH ₂ (where, R ³ is the number of carbon atoms An alkylene group having 1 to 6 carbon atoms, an alkylidene group having 1 to 6 carbon atoms, or an —OCO— group, wherein R ⁴ represents hydrogen or a methyl group), and has a number average molecular weight. The silicone resin composition according to claim 1, wherein the silicone resin composition is 2500 or more.   A silicone resin molded article obtained by radical copolymerization of the silicone resin composition according to claim 1. A silicone resin molded article, wherein the silicone resin molded article according to claim 2 satisfies the following conditions (a) to (d).
(B) Pencil hardness of 5H or more (b) Glass transition temperature of 300 ° C. or more (c) Linear expansion coefficient of 70 ppm / K or less (d) Visible light transmittance of 400 to 800 nm wavelength is 85% or more (e) Birefringence 1.0nm or less   A method for producing a silicone resin molded article, wherein the silicone resin composition according to claim 1 is radically copolymerized by heating or irradiation with energy rays.