JP2022098954A - Photocurable silicone resin composition and silicone resin molding obtained by curing the same, and method for manufacturing the molding - Google Patents

Abstract

To provide a photocurable silicone resin composition which can give a molding that has high pencil hardness, and is excellent in scratch resistance and bending resistance, and a silicone resin molding that is a three-dimensional crosslinked body obtained by curing the same.SOLUTION: A photocurable silicone resin composition is obtained by blending a reactive silicone resin (A), a polyfunctional alkylene oxide-modified unsaturated compound (B) that contains at least two unsaturated groups represented by -R3-CR4=CH2 or -CR4=CH2 in one molecule, in the formula, R3 represents an alkylene group, an alkylidene group or a -O-C(=O)- group, and R4 represents a hydrogen atom or an alkyl group, and further has an alkylene oxide-modified part, and a polyfunctional unsaturated compound (C) that contains the two or more unsaturated groups in one molecule and does not contain an alkylene oxide-modified part in a mass ratio of 1 to 50:10 to 40:10 to 80.SELECTED DRAWING: None

Description

The present invention is a photocurable silicone resin composition capable of obtaining a molded body having high pencil hardness, scratch resistance and bending resistance, and silicone resin molding which is a three-dimensional crosslinked body obtained by curing the photocurable silicone resin composition. Regarding the body.

In recent years, there has been an increasing need for design, weight reduction, and thinning in all fields such as displays, mobile devices, home appliances, and automobile parts. Lightweight metals and the like are used. However, plastics and some lightweight metals have a problem that their surface hardness is low and they are easily damaged. Therefore, a method of providing a hard coat layer that protects the surface is used.

Acrylic compositions are often used in such hardcoat layers. Acrylic compositions are generally formed and cured by a radical reaction caused by irradiation with active energy rays such as ultraviolet rays and electron beams, so that they can be cured in a short time and at a low temperature, and the toughness can be maintained by the resin composition to be blended. Widely used in paints and adhesives.

As an example of such a hard coat layer, the present inventors have focused on a reactive silicone resin having a cage-shaped structure and a reactive functional group, and have been studying a reaction having this cage-shaped structure. By increasing the number of reactive functional groups in the flexible silicone resin and blending it with an unsaturated compound capable of radical copolymerization in a specific ratio, a balance between high surface hardness, heat resistance, mechanical properties, dimensional stability, etc. can be achieved. It has been found that it is possible to provide an excellent and transparent silicone resin molded body, and it is disclosed that this can be suitably used as a substitute for inorganic glass (Patent Documents 1 and 2). Further, a method for producing a reactive silicone resin having such a cage-shaped structure is particularly disclosed in Patent Document 3.

However, although the silicone resin composition has a high surface hardness, there is a problem that cracks and peeling occur at the time of bending.

Japanese Patent No. 4558643 Japanese Patent No. 5698566 Japanese Unexamined Patent Publication No. 2004-143449

The present invention is a photocurable silicone resin composition capable of obtaining a molded body having high pencil hardness, scratch resistance and bending resistance, and silicone resin molding which is a three-dimensional crosslinked body obtained by curing the photocurable silicone resin composition. The challenge is to provide the body.

The present inventors have made such a photocurable silicone resin composition by containing a polymerizable compound having a specific structure as a radically polymerizable unsaturated compound in the composition in a specific ratio. We have found that the problem can be solved and have reached the present invention.

That is, in the present invention, the reactive silicone resin (A) and -R ³ -CR ⁴ = CH ₂ or -CR ⁴ = CH ₂ in one molecule [However, R ³ is an alkylene group, an alkylidene group or -O-. A polyfunctional alkylene oxide-modified unsaturated compound (indicating a C (= O) -group, where ^R4 represents a hydrogen atom or an alkyl group] containing at least two unsaturated groups represented by] and further having an alkylene oxide modification site. B) and the polyfunctional unsaturated compound (C) containing two or more of the unsaturated groups in one molecule and not containing an alkylene oxide modification site, having a mass of 1 to 50:10 to 40:10 to 80. It is a photocurable silicone resin composition characterized by being blended in a ratio.

According to the present invention, a photocurable silicone resin composition capable of obtaining a molded body having high pencil hardness, scratch resistance and bending resistance, and a three-dimensional crosslinked body obtained by curing the molded body. A silicone resin molded body can be provided.

Hereinafter, each element constituting the present invention will be described in detail, but the following description is an example of an embodiment of the present invention, and the present invention is limited to the following description as long as the gist thereof is not exceeded. It is not something that will be done. In addition, when the expression "-" is used in this specification, it shall be used as an expression including numerical values or physical property values before and after the expression. Further, in the present invention, when the expression "(meth) acrylic" is used, it means one or both of "acrylic" and "methacrylic". The same applies to "(meth) acrylate" and "(meth) acryloyl".

The photocurable silicone resin composition of the present invention comprises a reactive silicone resin (A) and -R ³ -CR ⁴ = CH ₂ or -CR ⁴ = CH ₂ in one molecule [where R ³ is an alkylene group. A polyfunctional alkylene containing at least two unsaturated groups represented by [alkylidene group or -OC (= O) -group, where ^R4 represents a hydrogen atom or an alkyl group] and having an alkylene oxide modification site. Oxide-modified unsaturated compound (B) and polyfunctional unsaturated compound (C) containing two or more of the unsaturated groups in one molecule and not containing an alkylene oxide-modified site are 1 to 50:10 to 40. : It is characterized by blending in a mass ratio of 10 to 80.

The reactive silicone resin (A) used in the present invention is preferably blended in a mass ratio of 1 to 50 with respect to 100 parts by mass of the photocurable silicone resin composition, more preferably 2.5 to 30. It is a mass ratio. If it is less than 1 part by mass, the crosslink density is lowered and the pencil becomes soft, and the scratch resistance and the pencil hardness are deteriorated. If it is more than 50 parts by mass, the crosslink density increases and becomes hard and brittle, causing cracks and peeling at the time of bending.

As the reactive silicone resin (A), a known silicone-based resin can be used, but a preferable mode is represented by the following general formula (1), and a polyorganosilsesqui having a cage-shaped structure in the structural unit. The main component is oxane (also referred to as cage-type polyorganosilsesquioxane. Polyorganosilsesquioxane is also referred to as silsesquioxane). In the general formula (1), R is an organic functional group having a (meth) acryloyl group, and n is 8, 10 or 12.
[RSiO _3/2 ] _n (1)
In the general formula (1), R is an organic functional group having a (meth) acryloyl group, and n is 8, 10 or 12. Examples of the organic functional group having a (meth) acryloyl group include a group represented by the following general formula (4). In the general formula (4), m is an integer of 1 to 3, and R ¹ is a hydrogen atom or a methyl group.
CH ₂ = CR ¹ -COO- (CH ₂ ) _m- (4)

Such a reactive silicone resin has an organic functional group having a (meth) acryloyl group on a silicon atom in the molecule. Specific structures of the cage-shaped polyorganosylsesquioxane in which n in the general formula (1) is 8, 10 and 12 are as shown in the following structural formulas (5), (6) and (7), respectively. A basket-shaped structure can be mentioned. In addition, R in the following formula represents the same thing as R in the general formula (1).

Here, such a reactive silicone resin can be produced by the method described in Patent Document 3 and the like. For example, the silicon compound represented by RSiX ₃ is hydrolyzed in the presence of a polar solvent and a basic catalyst and partially condensed, and the obtained hydrolysis product is further re-reduced in the presence of a non-polar solvent and a basic catalyst. It can be obtained by condensation. Here, R is an organic functional group having a (meth) acryloyl group, specifically, a group represented by the general formula (4), and X represents a hydrolyzable group. Specific examples of preferred R include 3-methacryloxypropyl group, methacryloxymethyl group, and 3-acryloxypropyl group.

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

Among the silicon compounds represented by RSiX3, preferred compounds are methacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxylane, ₃ -methacryloxypropyltrichlorosilane, 3-methacryloxypropyltrimethoxysilane, 3-. Examples thereof include methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-acryloxypropyltrichlorosilane. Above all, it is preferable to use 3-methacryloxypropyltrimethoxysilane, which is easily available as a raw material.

Examples of the basic catalyst used in the hydrolysis reaction include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and cesium hydroxide, or tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide and 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.

Regarding the hydrolysis reaction conditions, the reaction temperature is preferably 0 to 60 ° C, more preferably 20 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 reaction time. On the other hand, if the temperature is higher than 60 ° C., the reaction rate is too fast, so that a complicated condensation reaction proceeds, and as a result, the 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 hydrolyzing reaction may not proceed sufficiently and the hydrolyzable groups may remain in an unreacted state.

The presence of water is essential for the hydrolysis reaction, which can be supplied from an aqueous solution of a basic catalyst or may be added as separate water. The amount of water is often more than enough to hydrolyze the hydrolyzable group, preferably 1.0 to 1.5 times the theoretical amount. Further, it is necessary to use an organic polar solvent at the time of hydrolysis, and as the organic polar solvent, alcohols such as methanol, ethanol and 2-propanol, or other organic polar solvents can be used. It is preferably a lower alcohol having 1 to 6 carbon atoms which is soluble in water, and it is more preferable to use 2-propanol. When a non-polar solvent is used, the reaction system is not uniform, the hydrolysis reaction does not proceed sufficiently, and unreacted hydrolyzable groups remain, which is not preferable.

After completion of the hydrolysis reaction, water or the water-containing reaction solvent is separated. For the separation of water or the water-containing reaction solvent, means such as evaporation under reduced pressure can be adopted. In order to sufficiently remove water and other impurities, a non-polar solvent is added to dissolve the hydrolysis reaction product, the solution is washed with saline or the like, and then dried with a desiccant such as anhydrous magnesium sulfate. Means such as letting it be adopted can be adopted. The hydrolysis reaction product can be recovered by separating the non-polar solvent by means such as evaporation, but if the non-polar solvent can be used as a non-polar solvent to be used in the next reaction, it is separated. No need.

In the hydrolysis reaction, a condensation reaction of the hydrolyzate occurs together with the hydrolysis. The hydrolyzed product associated with the condensation reaction of the hydrolyzate is usually a colorless viscous liquid having a number average molecular weight of 1400 to 5000. The hydrolyzed product becomes an oligomer having a number average molecular weight of 1400 to 3000, which varies depending on the reaction conditions, and most of the hydrolyzable groups X, preferably almost all of them, are substituted with OH groups, and most of the OH groups are further substituted. Preferably 95% or more is condensed. Regarding the structure of the hydrolysis product, there are multiple types of cage-type, ladder-type, and random-type silsesquioxane, and the proportion of complete cage-type structures is small even for compounds having a cage-type structure. The main structure is an incomplete basket-shaped structure that is partially 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 (recondensate) a siloxane bond, thereby forming a cage-shaped silsesquioki. Selectively manufacture sun.

Specifically, it is performed as follows. That is, as described above, after the water or the water-containing reaction solvent is separated after the hydrolysis reaction is completed, the recondensation reaction is carried out in the presence of a non-protic solvent and a basic catalyst. Regarding the reaction conditions of the recondensation reaction, the reaction temperature is preferably in the range of 100 to 200 ° C, more preferably 110 to 140 ° C. Further, if the reaction temperature is too low, a sufficient driving force cannot be obtained for 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, so 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 non-polar solvent used is often sufficient to dissolve the hydrolysis reaction product, and the amount of the basic catalyst used is 0.1 to 10% by mass (wt%) with respect to the hydrolysis reaction product. It should be in the range of.

The non-polar solvent may be one that is insoluble or almost insoluble in water, but a hydrocarbon solvent is preferable. Examples of such hydrocarbon solvents include non-polar solvents having a low boiling point such as toluene, benzene, and xylene. Of these, it is preferable to use toluene. Further, as the basic catalyst, the basic catalyst used in the hydrolysis reaction can be used, and alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and cesium hydroxide, or tetramelammonium hydroxide and tetraethyl can be used. Examples thereof include ammonium hydroxide salts such as ammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide and benzyltriethylammonium hydroxide, but catalysts soluble in non-polar solvents such as tetraalkylammonium are preferred.

The hydrolysis product used for recondensation is preferably washed with water, dehydrated and concentrated, but can be used without washing with water or dehydration. In this reaction, water may be present, but it is not necessary to add it positively, and it is preferable to keep the amount of water brought in from the basic catalyst solution. If the hydrolyzed product is not sufficiently hydrolyzed, more water than the theoretical amount required to hydrolyze the remaining hydrolyzable groups is required, but the hydrolysis reaction is usually sufficient. It is done in. After the recondensation reaction, the catalyst is washed off with water and concentrated to obtain a silsesquioxane mixture. The resulting silsesquioxane mixture preferably has the same number of silicon atoms in the molecule as the number of (meth) acryloyl groups.

The silsesquioxane mixture thus obtained varies depending on the reaction conditions and the state of the hydrolysis product, but the constituents are 70% or more of the whole cage-type silsesquioxane, and the rest is a ladder. It is considered to be a type, random cross-linked type silsesquioxane. Since these are difficult to separate and require a great deal of labor, in the present invention, when the cage-type silsesquioxane represented by the general formula (1) is used, 70 kinds of cage-type silsesquioxane are used. It is preferable to use silsesquioxane containing% or more. If the cage-shaped silsesquioxane content is 70% or more, there is no difference in the obtained effect. The constituents of the plurality of cage-shaped silsesquioxane are 20 to 40% T8 represented by the general formula (5), 40 to 50% T10 represented by the general formula (6), and the others. The component is T12 represented by the general formula (7). T8 can be separated by precipitating as needle-like crystals by leaving the silsesquioxane mixture at 20 ° C. or lower. The content ratio of the cage-shaped silsesquioxane can be confirmed by using, for example, GPC, LC-MS, or the like.

Such a reactive silicone resin may be a mixture of T8 to T12, or one or 2 such as T8 may be separated or concentrated from the mixture, but the reactive silicone resin obtained by the above-mentioned production method may be used. Not limited to.

The polyfunctional alkylene oxide-modified unsaturated compound (B) has -R ³ -CR ⁴ = CH ₂ or -CR ⁴ = CH ₂ in the molecule [however, R ³ has an alkylene group, an alkylidene group or -OC (=). It represents an O) -group, where ^R4 represents a hydrogen atom or an alkyl group] and contains at least two unsaturated groups and has an alkylene oxide modification site. Here, the alkylene oxide denatured site is preferably ethylene oxide or propylene oxide. Further, it is preferable to include at least one alkylene oxide modification site for each unsaturated group. By containing the component (B), cracks and peeling during bending can be suppressed while maintaining high surface hardness.

The polyfunctional alkylene oxide-modified unsaturated compound (B) is preferably blended in a mass ratio of 10 to 40 with respect to 100 parts by mass of the photocurable silicone resin composition, more preferably in a mass ratio of 10 to 30. .. If it is less than 10 parts by mass, sufficient flexibility cannot be imparted, cracks and peeling occur at the time of bending, and if it is more than 40 parts by mass, the surface hardness is lowered, which causes the pencil hardness and scratch resistance to be lowered.

Examples of the polyfunctional alkylene oxide-modified unsaturated compound (B) include alkylene oxide-modified glycerin tri (meth) acrylate, alkylene oxide-modified diglycerin tetra (meth) acrylate, alkylene oxide-modified dipentaerythritol tetra (meth) acrylate, and alkylene. Examples thereof include osid-modified dipentaerythritol hexa (meth) acrylate, polyethylene glycol acrylate, and polypropylene glycol acrylate. In addition, these components (B) may be used alone or in combination of two or more.

Specifically, ethylene oxide 3 mol modified trimethylol propantriacrylate, ethylene oxide 6 mol modified trimethylol propantriacrylate, ethylene oxide 9 mol modified trimethylol propantriacrylate, propylene oxide 3 mol modified trimethylol propantriacrylate, ethylene oxide 4 mol modified. Pentaerythritol tetraacrylate, ethylene oxide 5 mol modified pentaerythritol tetraacrylate, ethylene oxide 6 mol modified dipentaerythritol hexaacrylate, ethylene oxide 12 mol modified dipentaerythritol hexaacrylate, ethylene oxide 3 mol modified glycerin triacrylate, propylene oxide 3 mol modified glycerin triacrylate , Ethylene oxide 4 mol modified diglycerin tetraacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, ethylene oxide 3 mol modified bisphenol A diacrylate, ethylene oxide 4 mol modified bisphenol A diacrylate, ethylene oxide 10 mol modified bisphenol A diacrylate, ethylene oxide 4 Examples thereof include molar-modified bisphenol F diacrylate, polyethylene glycol diacrylate, and polypropylene glycol diacrylate. Among these compounds, those having three or more photopolymerizable unsaturated groups are more preferable from the viewpoint of surface hardness, and at least one per unsaturated group from the viewpoint of suppressing cracks and peeling during bending. It is preferably a polyfunctional alkylene oxide-modified unsaturated compound containing an alkylene oxide moiety.

The polyfunctional unsaturated compound (C) containing no alkylene oxide modification site has -R ³ -CR ⁴ = CH ₂ or -CR ⁴ = CH ₂ in the molecule [However, R ³ is an alkylene group, an alkylidene group or -O. It is a compound containing an unsaturated group represented by —C (= O) − group, and ^R4 represents a hydrogen atom or an alkyl group], preferably containing at least two unsaturated groups, and more preferably (). C) A polyfunctional unsaturated compound containing a hydroxyl group in an amount of 20% by mass or more out of 100% by mass of the component.

The polyfunctional unsaturated compound (C) containing no alkylene oxide modification site has a good mass ratio of 10 to 80 with respect to 100 parts by mass of the photocurable silicone resin composition, more preferably a quality ratio of 30 to 80. be. If it is less than 10 parts by mass, cross-linking becomes insufficient, and scratch resistance and pencil hardness deteriorate. If it is more than 80 parts by mass, the crosslink density increases and becomes hard and brittle, causing cracks and peeling at the time of bending.

The polyfunctional unsaturated compound (C) containing no alkylene oxide modification site preferably contains 10 to 100% by mass of the polyfunctional unsaturated compound having two or more or three or more unsaturated groups. By blending such a polyfunctional unsaturated compound, a molded product having a high surface hardness can be obtained.

Examples of the unsaturated compound containing a hydroxyl group among the above polyfunctional unsaturated compounds include pentaerythritol triacrylate, glycerin dimethacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol tetraacrylate. Since these have hydroxyl groups in their molecules, the radicals generated by the interaction of the hydroxyl groups shortening the distance between the molecules rapidly react with the double bond, improving the curing rate and prior to the reaction between oxygen and radicals. Since radical polymerization proceeds, it becomes possible to suppress hardening inhibition due to oxygen.
As described above, the polyfunctional unsaturated compound (C) containing no alkylene oxide modification site, which is blended in the present silicone resin composition, is preferably an unsaturated compound containing 20% by mass or more of a hydroxyl group, more preferably. (C) is preferably an unsaturated compound containing a hydroxyl group in an amount of 30% by mass or more. Within this range, intramolecular interactions are effective. There is no particular upper limit to the composition, but if it exceeds 60% by mass, the increase in the oxygen inhibition inhibitory effect almost disappears.

On the other hand, examples of the polyfunctional unsaturated compound containing no hydroxyl group include trimethylolpropane triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate. In addition to these, all of the terminal hydroxy groups of the skeleton obtained by modifying some or all of the hydroxy groups of pentaerythritol and dipentaerythritol with glycols such as ethylene and isopropylene and γ-butyrolactone, etc. R ³ -CR ⁴ = CH ₂ or -CR ⁴ = CH ₂ [However, R ³ indicates an alkylene group, an alkylidene group or an -OC (= O)-group, and R ⁴ indicates a hydrogen atom or an alkyl group. ] Can also be used, such as a compound modified with an unsaturated group represented by. Alternatively, urethane acrylate, acrylic copolymer acrylate and the like can be exemplified. Further, these polyfunctional unsaturated compounds, unsaturated compounds containing no hydroxyl group, and the like may be used alone or in combination of two or more.

Further, the polyfunctional unsaturated compound (C) that does not contain the alkylene oxide modification site may be blended with a reactive monofunctional or other bifunctional monomer (unsaturated compound) as long as the surface hardness is not lowered. good. Examples of the monofunctional monomer include styrene, vinyl acetate, N-vinylpyrrolidone, butyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-decyl acrylate, isobonyl acrylate, dicyclopentenyloxyethyl acrylate, and phenoxy. Ethyl acrylate, trifluoroethyl methacrylate and the like can be exemplified. Examples of other bifunctional monomers include tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol A diglycidyl ether diacrylate, tetraethylene glycol diacrylate, and neopentyl glycol diacrylate hydroxypivalate. Can be done.
The monofunctional monomer and other bifunctional monomers are preferably contained in the polyfunctional unsaturated compound (C) containing no alkylene oxide modification site in an amount of 20% by mass or less, more preferably 10% by mass or less. If it is blended in an amount of more than 20% by mass, the surface hardness tends to decrease, which is not preferable.

The photocurable silicone resin composition of the present invention preferably further contains an active energy ray polymerization initiator (D). The amount of the active energy ray polymerization initiator (D) is 0.1 to 20 parts by mass, preferably 1 to 10 parts by mass with respect to 100 parts by mass of the photocurable silicone resin composition. If it is less than this range, cross-linking and deterioration of scratch resistance and pencil hardness can be suppressed. On the contrary, even if the content exceeds this range, further improvement in the reaction rate may not be expected.

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

Specific active energy ray polymerization initiators (D) include benzophenones such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and benzoin isobutyl ether as photoinitiators; acetophenone, 2,2-diethoxy-2. -Phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-phenylpropane-1-one, diethoxyacetophenone, 1-hydroxycyclohexylphenylketone, 2- Acetophenone series such as methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one; anthraquinones such as 2-ethylanthraquinone, 2-terriary butyl anthraquinone, 2-chloroanthraquinone and 2-amylanthraquinone. Classes; thioxanthones such as 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal, benzyl dimethyl ketal; benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, Benzophenones such as 4,4'-bismethylaminobenzophenone; phosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide and the like can be mentioned. .. These can be used alone or as a mixture of two or more, and further, tertiary amines such as triethanolamine and methyldiethanolamine, N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester. It can be used in combination with a photoinitiator aid such as a benzoic acid derivative such as.

Examples of the photosensitizer include 1,4-dimethoxynaphthalene, 1,4-diethoxynaphthalene, 1,4-di (n-propoxy) naphthalene, 1,4-di (i-propoxy) naphthalene, and 2,6-. Naphthalenes such as dimethoxynaphthalene, 2,6-diethoxynaphthalene, 2,6-di (n-propoxy) naphthalene, 2,6-di (i-propoxy) naphthalene, benzophenone, 4-methylbenzophenone, 4-( Methylphenylthio) phenyl] -phenylmethane, 4,4'-bis (diethylamino) benzophenone and other benzophenone systems can be preferably mentioned. The blending amount is in the range of 0.05 to 3 parts by mass, preferably in the range of 0.1 to 3 parts by mass with respect to the photocurable silicone resin composition from the viewpoint of photocurability and transparency. If it is less than 0.05 parts by mass, the effect of improving the sensitizer is not exhibited, and the expected effect of improving hardness cannot be obtained. Further, if it exceeds 3 parts by mass, coloring tends to be strong, so it is preferable to use it in the above range. A plurality of photosensitizers may be combined in order to adjust the photocurability and transparency.

The photocurable silicone resin molded body of the present invention can be produced by curing the above-mentioned photocurable silicone resin composition by irradiation with active energy rays such as visible light, ultraviolet rays, and electron beams, and is preferable. A cured molded product can be obtained by irradiating with ultraviolet rays having a wavelength of 10 to 400 nm or visible light having a wavelength of 400 to 700 nm. The wavelength of the light used is not particularly limited, but near-ultraviolet rays having a wavelength of 200 to 400 nm are particularly preferably used. Lamps used as ultraviolet sources include low-pressure mercury lamps (output: 0.4 to 4 W / cm), high-pressure mercury lamps (40 to 160 W / cm), ultra-high pressure mercury lamps (173 to 435 W / cm), and metal halide lamps. (80 to 160 W / cm) and the like can be exemplified.

As a method for obtaining a molded product (silicone resin copolymer or cured product) by irradiation with active energy rays such as light irradiation, either an oxygen blocking atmosphere or an air atmosphere may be used, but the composition of the present invention may be used. Is preferably carried out in an air atmosphere because it gives a good molded product even if it is polymerized and cured in an air atmosphere. For example, the photocurable silicone resin composition of the present invention is injected into a mold having an arbitrary cavity shape and made of a transparent material such as quartz glass, and ultraviolet rays are irradiated with an ultraviolet lamp to perform polymerization curing. In the present invention, a method for producing a molded body having a desired shape by removing the mold from the mold, or when a mold is not used, for example, using a doctor blade or a roll-shaped coater on a moving steel belt. A method of producing a sheet-shaped molded product by applying a photocurable silicone resin composition and polymerizing and curing it with an ultraviolet lamp can be exemplified.
The shape of the molded body is arbitrary, and may be a film, a coating film, or the like. This molded product is obtained by radically copolymerizing and curing the photocurable silicone resin composition of the present invention. The molded product or cured product of the present invention is a three-dimensional crosslinked polymer, and in this case, a molding and curing method similar to that of a thermosetting resin can be adopted.

Further, on various substrates such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), triacetyl cellulose (TAC), transparent polyimide (CPI), polyimide (PI), metal plates, and glass. An example is a method of forming a molded product as a hard coat film on the surface of a base material by applying the photocurable silicone resin composition of the present invention or diluting it with various organic solvents and applying and curing it. Specific examples thereof include a salivation method, a roller coating method, a bar coating method, a spray coating method, an air knife coating method, a spin coating method, a flow coating method, a curtain coating method and a dipping method. The coating film thickness is adjusted by the solid content concentration in consideration of the film thickness formed after drying and curing by an ultraviolet lamp. When an organic solvent is used for adjusting the solid content concentration, it is preferable to remove the organic solvent by drying or the like after coating. The drying temperature is a condition under which the substrate to be used is not deformed, and the drying time is preferably 1 hour or less from the viewpoint of productivity. Further, from the viewpoint of scratch resistance and adhesiveness, the thickness of the hard coating film is 0.5 to 100 μm, preferably 1 to 60 μm.

Specific examples of the organic solvent include aromatic organic solvents such as toluene and xylene, ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone, and ester organic solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate and isobutyl acetate. , Alcohol-based organic solvents such as methanol, ethanol, n-propanol, isopropanol, and n-butanol, glycol ether-based organic solvents such as propylene glycol monomethyl ether, and other known organic solvents can be used. In particular, it is preferable to contain a glycol-based organic solvent.

Examples of the glycol ether-based organic solvent include 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, and ethylene. Ethylene glycol ethers such as glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol dibutyl ether, ethylene glycol isoamyl ether, ethylene glycol monohexyl ether, ethylene glycol mono2-ethylhexyl ether, methoxyethoxyethanol, and ethylene glycol monoallyl ether, Examples thereof include propylene glycols such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether and butoxypropanol, and propylene glycol monomethyl ether is preferable.

The laminate (photocurable silicone resin laminate) containing the resin molded body of the present invention thus obtained has a pencil hardness (based on JIS K5600) of 2H or more, preferably 3H or more, and has a scratch resistance of steel. It is preferable that the wool test does not damage the product after a load of at least 1,500 g and 300 round trips. As for bending resistance, for a test piece of 80 x 50 mm square, the long side of the rectangle should be along the circumference of the cylinder in an acrylic cylinder with a diameter of 50 mm with the layer of the silicone resin molded body on the outside. It is preferable that the silicone resin molded body does not crack or peel off when wound.

Various additives can be added to the photocurable silicone resin composition of the present invention within a range not deviating from the object of the present invention. As various additives, organic / inorganic fillers, plasticizers, flame retardants, heat stabilizers, antioxidants, light stabilizers, UV absorbers, leveling materials, slippering agents, antistatic agents, mold release agents, foaming agents, etc. Examples thereof include nucleating agents, coloring agents, fluorescent whitening agents, cross-linking agents, dispersion aids, resin components and the like.

Hereinafter, examples of the present invention will be shown. The reactive silicone resin used in the following examples was obtained by the method shown in the following synthetic example.

[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 a 5% tetramethylammonium hydroxide aqueous solution (TMAH aqueous solution) as a basic catalyst. Add 15 ml of IPA and 12.69 g of 3-methacryloxypropyltrimethoxysilane (MTMS: SZ-6030 manufactured by Toray Dow Corning Silicone Co., Ltd.) to the dropping funnel, and while stirring the reaction vessel, add 30 of the MTMS IPA solution at room temperature. Dropped over minutes. After completion of MTMS dropping, 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. Anhydrous magnesium sulfate was filtered off and concentrated to obtain 25.8 g of a hydrolysis product (silsesquioxane). This silsesquioxane was a colorless viscous liquid soluble in various organic solvents.
Next, in a reaction vessel equipped with a stirrer, Dean-Stark apparatus, and a cooling tube, 20.65 g of silsesquioxane obtained above, 82 ml of toluene, and 3.0 g of a 10% TMAH aqueous solution were placed, and the mixture was gradually heated to add water. Distilled away. Further, the mixture was heated to 130 ° C. and the toluene was recondensed at the reflux temperature. The temperature of the reaction solution at this time was 108 ° C. After refluxing the toluene and stirring for 2 hours, the reaction was terminated. The reaction solution was washed with saturated brine until neutral, and then dehydrated with anhydrous magnesium sulfate. Anhydrous magnesium sulfate was filtered off and concentrated to obtain 18.77 g of the target cage-shaped silsesquioxane (mixture). The obtained cage-shaped silsesquioxane (S1) was a colorless viscous liquid soluble in various organic solvents.
Mass spectrometry after liquid chromatography separation of the reactants after the recondensation reaction revealed that the molecular structures of the above structural formulas (5), (6) and (7) had R as a methacryloyl group and ammonium. Molecular ions with ions are confirmed, and the composition ratio is T8: T10: T12: other is about 2: 4: 1: 3, and it can be confirmed that the silicone resin has a cage-shaped structure as a main component. In addition, T8, T10, and T12 correspond to those having R as a methacryloyl group in the formulas (5), (6), and (7), respectively.

[Example 1]
Cage-shaped silicone resin (S1) having the methacryloyl group of Synthesis Example 1 on all silicon atoms as a component of the reactive silicone resin (A): 25 parts by mass, ethylene oxide as a component of the polyfunctional alkylene oxide-modified unsaturated compound (B) 12 mol-modified dipentaerythritol hexaacrylate (B1) (trade name KAYARAD DPEA-12 manufactured by Nippon Kayaku Co., Ltd.): 20 parts by mass, dipentaerythritol hexaacrylate (Mw = 578) as a component of the polyfunctional unsaturated compound (C) .57, A mixture of 65:35 (mass ratio) of dipentaerythritol pentaacrylate (Mw = 524.52, number of acrylic groups = 5, number of hydroxyl groups = 1) and acrylic groups = 6, number of hydroxyl groups = 0) (C1) (Product name KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.): 55 parts by mass, 1-hydroxycyclohexyl-phenyl-ketone (D1) (trade name Omnirad 184 manufactured by IGM) was mixed as an active energy ray polymerization initiator (D), and the mixture was mixed. A photocurable silicone resin composition was obtained.

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 Industry Co., Ltd.): 1 part by mass. After mixing, the mixture was dried in the air using a bar coater on the polymethylmethacrylate side of a composite plate made of polymethylmethacrylate / polycarbonate (thickness 650 μm, length 10 cm, width 10 cm C001 manufactured by Escalbo Sheet). It was applied so that the film thickness was 10 μm, and dried at 80 ° C. for 5 minutes. Then, it was cured at an integrated exposure amount of 2,800 mJ / cm ² under an oxygen atmosphere to obtain a laminated body test piece formed by forming a layer of the present silicone resin molded body on the surface of the polymethylmethacrylate of the composite plate.

[Examples 2 to 14, Comparative Examples 1 to 5]
A photocurable silicone resin composition was obtained in the same procedure as in Example 1 except that the raw materials and composition ratios shown in Table 1 were used. Other abbreviations in the table are as follows.
DGE-4A: Ethylene oxide 4 mol modified diglycerin tetraacrylate (B2) (number of acrylic groups = 4, ethylene oxide modified number = 4, manufactured by Kyoeisha Chemical Co., Ltd.)
M3130: Ethylene oxide 3 mol modified trimethylolpropane triacrylate (B3) (number of acrylic groups = 3, ethylene oxide modified number = 3, manufactured by MIWON)
M3190: Ethylene oxide 9 mol modified trimethylolpropane triacrylate (B4) (number of acrylic groups = 3, ethylene oxide modified number = 9, manufactured by MIWON)
M320: Propylene oxide 3 mol-modified glycerin triacrylate (B5) (number of acrylic groups = 3, number of propylene oxide modifications = 3, manufactured by MIWON)
Light acrylate PE-3A (C2): 40:60 (mass ratio) of pentaerythritol tetraacrylate (acrylic group number = 4, number of hydroxyl groups = 0) and pentaerythritol triacrylate (number of acrylic groups = 3, number of hydroxyl groups = 1). Mixture (manufactured by Kyoeisha Chemical Co., Ltd.)
Light Acrylate TMP-A (C'1): Trimethylolpropane Triacrylate (acrylic group number = 3, hydroxyl group number = 0, manufactured by Kyoeisha Chemical Co., Ltd.)

[evaluation]
The following evaluation was performed using the laminated body test piece obtained above. The evaluation results are shown in Tables 1 to 3.

[Pencil hardness]
According to JIS K 5600, the surface of the laminated body test piece on the silicone resin molded body side was scratched with a Mitsubishi Pencil Uni at a load of 750 g and an angle of 45 degrees, and the hardness without scratches was visually determined.

[Scratch resistance]
Using # 0000 steel wool and using a reciprocating wear tester (Type: 30S manufactured by HEIDON), the surface of the laminated body test piece on the silicone resin molded body side was worn under a load of 1.5 kg / cm ² . A scratch with a length of 1 mm or more was judged to be a scratch, and the presence or absence of the scratch was visually observed under a fluorescent lamp, and the number of scratches was evaluated according to the following criteria.
◎: No scratches on 1,000 round trips 〇: No scratches on 300 round trips △: Less than 10 scratches on 300 round trips ×: 10 or more scratches on 300 round trips

[Bending resistance]
The laminated body test piece is cut into 80 x 50 mm squares, and each is wound around an acrylic cylinder having a diameter of 50 mm with the silicone resin molded body side as the outside so that the long side of the rectangle is along the circumference of the cylinder. Deformation and cracks of the resin molded body were visually observed.
○: No cracks or peeling occur ×: Cracks or peeling occur

Claims (8)

Reactive silicone resin (A) and
-R ³ -CR ⁴ = CH ₂ or -CR ⁴ = CH ₂ in one molecule [However, R ³ indicates an alkylene group, an alkylidene group or an -OC (= O) -group, and R ⁴ is a hydrogen atom. Or a polyfunctional alkylene oxide-modified unsaturated compound (B) containing at least two unsaturated groups represented by [or an alkyl group] and further having an alkylene oxide modification site.
A polyfunctional unsaturated compound (C) containing two or more of the unsaturated groups described above in one molecule and not containing an alkylene oxide modification site was blended in a mass ratio of 1 to 50:10 to 40:10 to 80. A photocurable silicone resin composition characterized by this. The polyfunctional alkylene oxide-modified unsaturated compound (B) has -R ³ -CR ⁴ = CH ₂ or -CR ⁴ = CH ₂ in the molecule [however, R ³ has an alkylene group, an alkylidene group or -OC (=). O) -indicates a-group, ^R4 represents a hydrogen atom or an alkyl group] contains at least two unsaturated groups, and the alkylene oxide modification site is ethylene oxide or propylene oxide, with respect to one unsaturated group. The photocurable silicone resin composition according to claim 1, further comprising a polyfunctional alkylene oxide-modified unsaturated compound containing at least one alkylene oxide-modified site. The polyfunctional unsaturated compound (C) has -R ³ -CR ⁴ = CH ₂ or -CR ⁴ = CH ₂ in the molecule [however, R ³ has an alkylene group, an alkylidene group or -OC (= O)-. Represents a group, where ^R4 represents a hydrogen atom or an alkyl group] contains at least two unsaturated groups, and 20% by mass or more of 100% by mass of the component (C) contains a hydroxyl group. The photocurable silicone resin composition according to claim 1 or 2, which is a compound. The reactive silicone resin (A) is the general formula (1).
[RSiO _3/2 ] _n (1)
[However, R is an organic functional group having a (meth) acryloyl group, and n is 8, 10 or 12], and the main component is polyorganosylsesquioxane having a cage-shaped structure in the structural unit. The photocurable silicone resin composition according to any one of claims 1 to 3, wherein the composition is. The photocurable silicone resin composition according to any one of claims 1 to 4, which contains an active energy ray polymerization initiator (D). A photocurable silicone resin molded product obtained by radically copolymerizing and curing the photocurable silicone resin composition according to any one of claims 1 to 5. A photocurable silicone resin laminate obtained by applying the photocurable silicone resin composition according to any one of claims 1 to 5 to a substrate, subjecting it to radical copolymerization, and curing it. The photocurable silicone resin composition according to any one of claims 1 to 5 is irradiated with active energy rays in the atmosphere and radically copolymerized to obtain a silicone resin molded product. A method for manufacturing a resin molded product.