JP6456632B2 - Photosensitive resin composition - Google Patents

Description

  The present invention relates to a photosensitive resin composition.

In the liquid crystal display, a reflector is disposed on the back surface of the liquid crystal screen to prevent escape of screen light. For a reflector that requires a high light reflectance, a white film having a high reflectance is used. A study of diverting a technique related to a lamp shade for a lighting fixture that requires a similar high light reflectance to a surface light source reflector is also underway. As a typical high light reflection material, there is a reflection material such as an Ag vapor deposition film in which a metal vapor deposition film is deposited on a substrate surface to form a mirror surface. Although a vapor deposition film has a high specular reflectance, it does not easily cause diffuse reflection, and the amount of light directed to a display surface such as a liquid crystal decreases.
As a reflective material that replaces the Ag vapor-deposited film, a thermoplastic polyester foam containing fine bubbles (Patent Document 1), a reflector having a resin coating film in which silica aerogel is dispersed (Patent Document 2), and the like are known. Yes.

Japanese Patent No. 2925745 JP-A-11-29745

  However, in the reflective material and the reflective film whose reflectance is increased by foaming of the resin of Patent Document 1, reflection is promoted at the interface between the film resin and the fine bubbles having greatly different refractive indexes, regardless of the presence or absence of a white pigment such as titanium oxide. Although it exhibits a white surface with a high reflectance, it is necessary to increase the film thickness in order to improve the reflectance. Generally, a reflective film is produced by dissolving and extruding a film of polyester or the like and then incorporating fine bubbles inside the film by a method of stretching uniaxially or biaxially. As the film thickness is increased, the reflectance is improved. However, the cost is high and the productivity is low, and the film thickness is about 150 to 200 μm, so the reflectance is insufficient.

  Moreover, since the reflector on the back surface of the liquid crystal display screen of Patent Document 2 is irradiated with illumination light from a fluorescent tube or LED, it is always irradiated with ultraviolet rays that are contained in the illumination light in a small amount. In the reflective material and reflective film whose reflectance is increased with foamed resin, there is a problem that the resin itself deteriorates due to ultraviolet rays, and as the time passes, discoloration of the coating proceeds and total reflection and diffuse reflection decrease. .

Therefore, by developing a coating film made from thermosetting acrylic paint as a surface coating film, we have developed a sheet for liquid crystal backlight reflectors that improves the efficiency of illumination light use and does not decrease the reflectivity even after prolonged use. Has been. However, the thermosetting method still has a problem that productivity is poor and a large amount of energy is consumed.
Moreover, when using as an optical member in which the resin coating film was formed on glass, it is calculated | required that resin has high adhesiveness with respect to glass.

  An object of this invention is to provide the photosensitive resin composition which can form the coating film which has high adhesiveness with respect to glass, and has a high reflectance efficiently.

The inventors of the present invention have reached the present invention as a result of studies to achieve the above object.
That is, the present invention relates to a resin (A) having a radical polymerizable group having a number average molecular weight of 1,000 to 50,000, a compound (B) having two or more radical polymerizable groups other than (A), A photosensitive resin composition comprising a compound (C) having a decomposable alkoxy group, a photopolymerization initiator (D) and titanium oxide (E) as essential components.

  The photosensitive resin composition of the present invention has an effect that a coating film having high adhesion to glass and having a high reflectance can be efficiently formed.

  A resin (A) having a radical polymerizable group having a number average molecular weight of 1,000 to 50,000, a compound (B) having two or more radical polymerizable groups other than (A), and a hydrolyzable alkoxy group It contains a compound (C), a photopolymerization initiator (D), and titanium oxide (E) as essential components. Moreover, the coating film obtained by hardening this composition has high adhesiveness with respect to glass, and can make a reflectance high.

  In this specification, “(meth) acrylate” means “acrylate or methacrylate”, “(meth) acrylic acid” means “acrylic acid or methacrylic acid”, and “(meth) acrylic resin” means “ “Acrylic resin or methacrylic resin”, “(meth) acryloyl group” means “acryloyl group or methacryloyl group”, and “(meth) acryloyloxy group” means “acryloyloxy group or methacryloyloxy group”.

  Below, (A)-(E) which is an essential structural component of the photosensitive resin composition of this invention is demonstrated in order.

The number average molecular weight in the resin (A) having a radical polymerizable group having a number average molecular weight of 1,000 to 50,000, which is the first essential component in the photosensitive resin composition of the present invention, is determined by gel permeation chromatography. It is a measured value by the method (hereinafter abbreviated as GPC).
The number average molecular weight of (A) is usually 1,000 to 50,000, preferably 1,500 to 30,000, more preferably 2,000 to 20,000, from the viewpoint of the strength of the cured coating film.

  The number average molecular weight in the present invention uses HLC-8320GPC (manufactured by Tosoh Corp.) as a GPC device, and is a tetrahydrofuran solvent, using TSK standard polystyrene (manufactured by Tosoh Corp.) as a reference substance, measuring temperature: 40 ° C., Column: measured with Alliance (manufactured by Waters). Moreover, GPC workstation EcoSEC-WS (made by Tosoh Corporation) is used as analysis software.

The resin (A) having a radical polymerizable group having a number average molecular weight of 1,000 to 50,000 used in the present invention has a radical polymerizable group in the molecule.
Examples of the radical polymerizable group include (meth) acryloyl group, vinyl group, allyl group, and propenyl group. From the viewpoint of photocurability, (meth) acryloyl group, vinyl group, and allyl group are preferable, and ( A (meth) acryloyl group.

  The resin (A) having a radical polymerizable group preferably has a hydrogen bondable functional group in the molecule together with the radical polymerizable group, and the hydrogen bondable functional group is from the viewpoint of adhesion. A carboxyl group, a hydroxyl group, a sulfonic acid group and a phosphoric acid group are preferable, and a carboxyl group is more preferable.

  Specific examples of the resin (A) having a radical polymerizable group that can be used in the present invention include an epoxy resin (A1) having a radical polymerizable group and a (meth) acrylic resin (A2) having a radical polymerizable group. ) And the like.

  The epoxy resin (A1) having a radical polymerizable organic group can be obtained by reacting a commercially available epoxy resin with a compound having a radical polymerizable organic group. Further, by further reacting a compound having a hydrogen bonding functional group, a compound having a hydrogen bonding functional group in the molecule can be obtained. For example, a novolak type epoxy resin having an epoxy group in the molecule ( Examples include those obtained by reacting (meth) acrylic acid and further reacting with a polyvalent carboxylic acid such as phthalic acid or phthalic anhydride or a polyvalent carboxylic acid anhydride.

The (meth) acrylic resin (A2) having a radical polymerizable group can be obtained by polymerizing a (meth) acrylic acid derivative by an existing method and further reacting a compound having a radical polymerizable group.
As a method for producing the (meth) acrylic resin (A2), radical polymerization is preferable, and a solution polymerization method is preferable because the molecular weight can be easily adjusted.

  Examples of the monomer constituting the (meth) acrylic resin (A2) include (meth) acrylic acid (a21), (meth) acrylic acid ester (a22), and maleic anhydride.

  As (meth) acrylic acid ester (a22), alkyl (meth) acrylate having 1 to 24 carbon atoms [methyl (meth) acrylate, butyl (meth) acrylate and (meth) acrylic acid-2-ethylhexyl, etc.] and Examples thereof include hydroxyalkyl (meth) acrylate having 1 to 24 carbon atoms [hydroxyethyl (meth) acrylate, etc.], preferably methyl (meth) acrylate.

  As a monomer constituting the (meth) acrylic resin (A2), from the viewpoint of elastic recovery characteristics of the photosensitive resin composition, a vinyl compound (a23) (styrene or the like) having an aromatic ring is substituted with (meth) acrylic acid (a21 ) And (meth) acrylic acid ester (a22).

  Examples of the method for introducing a (meth) acryloyl group into the side chain include the following methods (1) and (2).

(1) Groups capable of reacting with isocyanate groups (hydroxyl groups or primary or secondary amino groups, etc.) in at least a part of the monomers [(a21) and (a22) etc.] constituting the (meth) acrylic resin (A2) ) And a monomer having a (meth) acryloyl group and an isocyanate group (such as (meth) acryloyloxyethyl isocyanate).

(2) At least a part of the monomers ((a21) and (a22) etc.) constituting the (meth) acrylic resin (A2) (groups capable of reacting with an epoxy group (hydroxyl group, carboxyl group and primary or secondary) A method of producing a polymer using a monomer having an amino group and the like, and then reacting a compound having a (meth) acryloyl group and an epoxy group (such as glycidyl (meth) acrylate).

  When the resin (A) in the photosensitive resin composition of the present invention contains an acidic group, for example, a carboxyl group, a sulfone group or a phosphoric acid group, the acid value of (A) is preferably 50 from the viewpoint of adhesion. To 200, more preferably 70 to 180, and particularly preferably 80 to 150.

  The acid value in the present invention can be measured by potentiometric titration in accordance with JIS K0070. As the measurement solvent, acetone, methanol, a mixed solution of acetone and methanol, or the like is used.

The content of the resin (A) in the present invention is preferably 5 to 60% by weight, more preferably 10 to 50% by weight, based on the weight of solid content in the photosensitive resin composition, from the viewpoint of adhesion. is there.
In addition, the weight of the solid content of the photosensitive resin composition is the weight of components other than the solvent (J) described later in the photosensitive resin composition, and is hereinafter used in the same meaning.

  As the compound (B) having two or more radical polymerizable groups other than (A) which is the second essential component in the photosensitive resin composition of the present invention, a (meth) acryloyl group, a vinyl group, Examples include compounds having two or more radically polymerizable groups selected from the group consisting of allyl groups and propenyl groups, and compounds having a (meth) acryloyl group [namely, (meth) acrylates] are preferred, and two or more (meth ) A compound having an acryloyl group is more preferred.

The compound having two or more (meth) acryloyl groups in the molecule is not particularly limited as long as it is a known polyfunctional (meth) acrylate monomer.
As such a polyfunctional (meth) acrylate monomer, bifunctional (meth) acrylate (B1), trifunctional (meth) acrylate (B2), 4-6 functional (meth) acrylate (B3), and 7-10 functional ( And (meth) acrylate (B4).

  Examples of the bifunctional (meth) acrylate (B1) include esterified products of polyhydric alcohol and (meth) acrylic acid [for example, di (meth) acrylate of glycol, di (meth) acrylate of glycerin, dimethyl methacrylate). (Meth) acrylate, di (meth) acrylate of 3-hydroxy-1,5-pentanediol and di (meth) acrylate of 2-hydroxy-2-ethyl-1,3-propanediol]; alkylene oxide of polyhydric alcohol Adduct and esterified product of (meth) acrylic acid [for example, di (meth) acrylate of trimethylolpropane ethylene oxide adduct and di (meth) acrylate of glycerin ethylene oxide adduct]; ; With polyhydric alcohol (me ) Esters of acrylic acid and hydroxycarboxylic acid [e.g., hydroxypivalic acid neopentyl glycol di (meth) acrylate], and the like.

  Trifunctional (meth) acrylate (B2) includes tri (meth) acrylate of glycerin, tri (meth) acrylate of trimethylolpropane, tri (meth) acrylate of pentaerythritol, and trioxide of ethylene oxide adduct of trimethylolpropane ( And (meth) acrylate.

  Examples of the 4- to 6-functional (meth) acrylate (B3) include pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, hexapentamethacrylate of dipentaerythritol, and an ethylene oxide adduct of dipentaerythritol. Examples include tetra (meth) acrylate, penta (meth) acrylate of an ethylene oxide adduct of dipentaerythritol, and penta (meth) acrylate of a propylene oxide adduct of dipentaerythritol.

  Examples of 7 to 10 functional (meth) acrylate compounds include diisocyanate compounds and polyfunctional (meth) acrylate compounds having a hydroxyl group, such as compounds obtained by reaction of dipentaerythritol penta (meth) acrylate and hexamethylene diisocyanate. It can be obtained by reaction.

  The content of the compound (B) having two or more radical polymerizable groups other than (A) in the photosensitive resin composition of the present invention is such that the content in the photosensitive resin composition is from the viewpoint of curability and adhesion. Preferably it is 0.5 to 20 weight%, More preferably, it is 1 to 15 weight% based on the weight of solid content.

  As the compound (C) having a hydrolyzable alkoxy group, which is the third essential component in the photosensitive resin composition of the present invention, a compound having an alkoxy group such as alkoxytitanium, alkoxysiloxane, alkoxyaluminum and alkoxyzirconia, and its Examples include condensates.

  The compound (C) having a hydrolyzable alkoxy group is preferably an alkoxysilane and an alkoxysiloxane from the viewpoint of improving adhesion, and more preferably a silane compound represented by the following general formula (1) and a condensate thereof. It is a certain siloxane compound.

In general formula (1), R ¹ is a (meth) acryloyloxyalkyl group having 1 to 6 carbon atoms in the alkyl group, a glycidoxyalkyl group having 1 to 6 carbon atoms in the alkyl group, or an alkyl group Represents one or more organic groups selected from the group consisting of a mercaptoalkyl group having 1 to 6 carbon atoms and an aminoalkyl group having 1 to 6 carbon atoms in the alkyl group, and R ² represents 1 to 1 carbon atoms. 12 represents an aliphatic saturated hydrocarbon group or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and R ³ represents an alkyl group having 1 to 4 carbon atoms. m is 0 or 1.

Examples of the aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms in R ^2, a straight-chain alkyl groups include branched alkyl group and alicyclic saturated hydrocarbon group.

Examples of the linear alkyl group include methyl, ethyl, n-propyl, n-butyl, n-octyl and n-dodecyl groups, and their deuterium substitutes.
Examples of the branched alkyl group include isopropyl, isobutyl, sec-butyl and 2-ethylhexyl groups.
Examples of the cyclic saturated hydrocarbon group include a cyclohexyl group, a cyclooctyl group, a cyclohexylmethyl group, a cyclohexylethyl group, and a methylcyclohexyl group.

  Examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms include an aryl group, an aralkyl group, and an alkylaryl group.

Examples of the aryl group include phenyl, biphenyl, naphthyl groups, their deuterium, fluorine and chlorine substituents.
Examples of the aralkyl group include tolyl, xylyl, mesityl, and their deuterium, fluorine, or chloride.
Examples of the alkylaryl group include methylphenyl and ethylphenyl groups.

R ² is preferably a linear alkyl group, a branched alkyl group or an aryl group from the viewpoint of curing reactivity, more preferably a linear alkyl group or an aryl group, and particularly preferably a methyl group or ethyl group. Group and phenyl group.
Examples of R ³ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a sec-butyl group, and a methyl group and an ethyl group are preferable from the viewpoint of thermosetting reactivity. .
A plurality of R ³ may be the same or different.

In the general formula (1), examples of the silane compound having a (meth) acryloyloxyalkyl group having 1 to 6 carbon atoms in the alkyl group as R ¹ include the following compounds.
m is 0, that is, a trifunctional silane compound having three alkoxy groups: 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltrimethoxysilane, and 3- Acryloyloxypropyltriethoxysilane, etc.

  m is 1, that is, a trifunctional silane compound having two alkoxy groups: 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-acryloyloxypropylmethyldimethoxysilane and 3 -Acryloyloxypropylmethyldiethoxysilane, etc.

The silane compound the carbon number of the alkyl group as R ¹ has a glycidoxy alkyl group is 1 to 6, include compounds such as the following.
m is 0, that is, a trifunctional silane compound having three alkoxy groups, such as 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane. m is 1, that is, two alkoxy groups are 3 Functional silane compounds: 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, etc.

Examples of the silane compound having a mercaptoalkyl group having 1 to 6 carbon atoms in the alkyl group as R ¹ include the following compounds.
m is 0, that is, a trifunctional silane compound having three alkoxy groups, such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane. m is 1, that is, a trifunctional silane compound having two alkoxy groups. ..3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, etc.

Examples of the silane compound having an aminoalkyl group having 1 to 6 carbon atoms as the alkyl group as R ¹ include the following compounds.
m is 0, that is, trifunctional silane compound having three alkoxy groups: N-2 aminoethyl γ-aminopropyltrimethoxysilane, N-2 aminoethyl γ-aminopropyltriethoxysilane, 3-aminopropyltrimethoxy Silane, 3-aminopropyltriethoxysilane, etc. m is 1, that is, a trifunctional silane compound having two alkoxy groups: N-2 aminoethyl γ-aminopropylmethyldimethoxysilane, N-2 aminoethyl γ-aminopropyl Methyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, etc.

  Examples of commercially available silane compounds represented by the general formula (1) include methacryl-modified alkoxysilanes (KBM-503, KBM-5103, and KBE-502 [all manufactured by Shin-Etsu Chemical Co., Ltd.]).

The siloxane compound is a condensate of the silane compound represented by the general formula (1), and can be obtained by a known method such as a condensation reaction using an acid catalyst.
A silane compound may be used individually by 1 type, and may be used in combination of 2 or more types.

  Of the compounds (C) having a hydrolyzable alkoxy group, a trifunctional silane compound having a (meth) acryloyloxyalkyl group having three alkoxy groups and a trifunctional having a (meth) acryloyloxyalkyl group are preferable. A condensate having a silane compound as an essential constituent monomer and a condensate having a trifunctional silane compound having a glycidoxyalkyl group having three alkoxy groups as an essential constituent monomer, more preferably 3- It is a condensate containing (meth) acryloyloxypropyltrimethoxysilane and 3- (meth) acryloyloxypropyltrimethoxysilane as essential constituent monomers.

  The content of the compound (C) having a hydrolyzable alkoxy group in the present invention is preferably 0.1 to 20 weights based on the weight of the solid content in the photosensitive resin composition from the viewpoint of curability and adhesion. %, More preferably 1 to 15% by weight.

  The photopolymerization initiator (D), which is the fourth essential component in the photosensitive resin composition of the present invention, is polymerizable unsaturated by exposure to radiation such as visible light, ultraviolet light, far infrared light, charged particle beam and X-ray. Any component that generates a radical capable of initiating polymerization of a compound may be used.

  Examples of the photopolymerization initiator (D) include an acetophenone derivative (D1), an acyl phosphine oxide derivative (D2), a titanocene derivative (D3), a triazine derivative (D4), a bisimidazole derivative (D5), and an O-acyl oxime. (Oxime ester) derivative (D6), benzophenone derivative (D7), thioxanthone derivative (D8), α-diketone derivative (D9), anthraquinone derivative (D10) and a mixture containing two or more of these.

  Examples of the acetophenone derivative (D1) include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, benzyldimethyl ketal, 2-hydroxy-2-methylpropiophenone, 4-isopropyl-2-hydroxy-2-methylpropiophenone, 2 -Methyl-1- (4- (methylthio) phenyl) -2-morpholino-1-propan-1-one, dimethylbenzyl ketal, methylbenzoylformate and 2-benzyl-2-dimethylamino-1- (4-moly Morpholinopropane phenyl) - butan-1-one] and the like.

  Examples of the acylphosphine oxide derivative (D2) include trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide.

Examples of the titanocene derivative (D3) include bis (η ⁵ -2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium. It is done.

  Examples of the triazine derivative (D4) include trichloromethyltriazine and benzyl-2,4,6- (trihalomethyl) triazine.

  Examples of the bisimidazole derivative (D5) include 2- (o-chlorophenyl) -4,5-diphenylimidazolyl dimer.

  Examples of the O-acyloxime (oxime ester) derivative (D6) include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] and ethanone, 1- [9. -Ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime).

  Examples of the benzophenone derivative (D7) include benzophenone, 4,4-bis (dimethylamino) benzophenone, 3,3-dimethyl-4-methoxy-benzophenone, and Michler's ketone.

  Examples of the thioxanthone derivative (D8) include isopropylthioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, and diisopropylthioxanthone.

  Examples of the α-diketone derivative (D9) include camphorquinone.

  Examples of the anthraquinone derivative (D10) include anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, and tert-butylanthraquinone.

  Of these (D1) to (D10), (D1), (D2), and (D8) are preferable from the viewpoint of ease of synthesis, and 2-methyl-1- (4- (methylthio) phenyl) -2- Morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide and diethylthioxanthone Are more preferable, and 2-methyl-1- (4- (methylthio) phenyl) -2-morpholino-1-propanone and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide are preferable from the viewpoint of reactivity. Particularly preferred.

  From the viewpoint of curability, at least one of the photopolymerization initiators (D) preferably has an absorbance at a wavelength of 400 nm or more, and more preferably has an extinction coefficient of 100 or more at a wavelength of 405 nm. 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one [Irgacure 369 (BASF, extinction coefficient at 405 nm: 280)], bis (2,4 , 6-trimethylbenzoyl) -phenylphosphine oxide [Irgacure 819 (manufactured by BASF, extinction coefficient at 405 nm: 899)], 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide [lucirin TPO (manufactured by BASF) , Extinction coefficient at 405 nm: 165)] and 1,2-octanedione 1- [4- Phenylthio) -, 2-(O-benzoyl oxime)] [IRGACURE OXE01 (BASF Corp., extinction coefficient at 405 nm: 102)], and the like.

  The absorbance in the present invention can be measured using an ultraviolet-visible spectrophotometer [“UV-2550” manufactured by Shimadzu Corporation] in the range of 200 to 500 nm in accordance with JIS K0115. As a measurement sample, a photopolymerization initiator (D) dissolved in a solvent having no absorption at a wavelength of 200 to 500 nm (acetonitrile, methanol, etc.) at a concentration of 0.001 to 0.01% by weight is used. .

  The content of the photopolymerization initiator (D) of the present invention is preferably 1 to 20% by weight, more preferably 3 to 18% by weight, particularly preferably based on the weight of the solid content in the photosensitive resin composition. 5 to 15% by weight. If it is 1% by weight or more, curing reactivity can be exhibited more satisfactorily, and if it is 20% by weight or less, reduction of yellowing of the cured product after photoexposure can be exhibited more satisfactorily.

  As titanium oxide (E) which is the fifth essential component in the photosensitive resin composition of the present invention, since whiteness varies depending on the production method, it is preferable to select titanium oxide having high whiteness in order to improve reflectivity. Impurities of heavy metals and metal oxides mixed during the purification of titanium oxide have an adverse effect on whiteness, and coloring with Fe, Cr, Cu, Mn, V, Nb, etc. is particularly harmful. Therefore, it is preferable that the impurities of heavy metals and metal oxides be regulated to 0.1% by mass or less as impurities.

  Titanium oxide having an impurity content of 0.1% by mass or less can be prepared by surface-treating rutile titanium oxide preferably made by a chlorine method with alumina, silica, zirconia, titania, organic matter, or the like. The particle diameter of titanium oxide effective for improving the reflectivity is preferably 0.1 to 0.5 μm, more preferably 0.2 to 0.4 μm. Examples of the chlorinated titanium oxide include Taipur R900 and R920 (manufactured by DuPont), Taipaque CR50, CR58, CR67, PFC-105 and PFC-107 (manufactured by Ishihara Sangyo).

  The content of titanium oxide (E) of the present invention is preferably 30 to 90% by weight, more preferably 35 to 85% by weight, and particularly preferably 40 to 40% by weight based on the weight of the solid content in the photosensitive resin composition. 80% by weight. If it is 30% by weight or more, the reflectance is even better, and if it is 90% by weight or less, the handling property during coating can be further improved.

  The photosensitive resin composition according to the present invention may further contain other components as necessary. Other components include monofunctional (meth) acrylate (F) other than (A) and (C), leveling agent (G), antioxidant (H), extender pigments (barium sulfate and tie), sensitizer , Polymerization inhibitors, solvents (J), thickeners and other additives (for example, fluorescent brighteners, yellowing inhibitors, defoamers and deodorants).

The monofunctional (meth) acrylate (F) in the present invention is preferably a (meth) acrylate having a phosphate group, a carboxyl group or a hydroxyl group, more preferably a (meth) acrylate having a phosphate group, from the viewpoint of adhesion. It is.
Examples of the (meth) acrylate containing a hydroxyl group include hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate, and examples of the (meth) acrylate having a phosphate group include 2- (meth) acryloyloxyethyl acid. A phosphate etc. are mentioned.

  The content of the monofunctional (meth) acrylate (F) of the present invention is preferably 0 to 20% by weight, more preferably 0.5 to 15% by weight, based on the weight of the solid content in the photosensitive resin composition. Particularly preferably, it is 1 to 10% by weight.

  Examples of the leveling agent (G) include anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, fluorine surfactants, and silicon surfactants. Among (G), from the viewpoint of applicability, fluorine-based surfactants and silicon-based surfactants are preferable.

  Examples of the antioxidant (H) include phenol-based antioxidants, sulfur-based antioxidants, and amine-based antioxidants. Among these, from the viewpoint of photocurability and antioxidant ability, phenolic antioxidants are preferable, and 2,6-di-t-butyl-4-methylphenol (BHT) and 2-t-butyl are particularly preferable. -6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1- (2-hydroxy-3,5-di-t-pentylphenyl) ethyl]- 4,6-di-t-pentylphenyl acrylate, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate ("Irganox 1076" manufactured by BASF), thiodiethylene bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (Irganox 1035), ethylenebis (oxyethylene) bis [3 (5-tert-butyl-4-hydroxy-m-tolyl) propionate] ("Irganox 245" manufactured by BASF), hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (Irganox 259) and pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] ("Irganox 1010" manufactured by BASF).

  Solvents (J) include ketone solvents (such as cyclohexanone), ether solvents (including ether ester solvents and ether alcohol solvents) (such as propylene glycol monomethyl ether acetate and methoxybutyl acetate), ester solvents (such as butyl acetate), ether solvents (Ether ester solvent and ether alcohol solvent, etc.), alcohol solvent (including ketone alcohol solvent) (1.3-butylene glycol and diacetone alcohol, etc.), ester solvent (ethyl lactate, etc.) and ketone solvent (acetone, methyl ethyl ketone, etc.) Etc.

  As a method for forming a cured product from the photosensitive resin composition of the present invention, for example, the photosensitive resin composition of the present invention is applied to a glass plate and irradiated with active energy rays (such as ultraviolet rays, electron beams, and visible rays). It is formed by photocuring. These operations may be performed a plurality of times.

  As a method for applying the photosensitive resin composition, a known method such as roll coating, gravure coating, curtain flow coating, pouring coating, rotary coating using a wheeler or spinner, spray coating, or silk screen printing is used. It can be carried out.

When the photosensitive resin composition of the present invention is cured by ultraviolet rays, various ultraviolet irradiation devices [model number “VPS / I600”, manufactured by Fusion UV Systems Co., Ltd.] can be used. Examples of the lamp light source to be used include a high-pressure mercury lamp, a metal halide lamp, and an LED. The dose of ultraviolet rays is preferably from the viewpoint of curability of the composition 10~1,000mJ / cm ^2, more preferably from 40~500mJ / cm ^2.

  Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these. Hereinafter, unless otherwise specified, “%” represents “% by weight” and “parts” represents “parts by weight”.

Production Example 1 [Production of Resin (A-1) Having Radical Polymerizable Group]
In a glass flask equipped with a heating / cooling / stirring device, a reflux condenser, a dropping funnel and a nitrogen introduction tube, 200 parts of cresol novolac epoxy resin “EOCN-102S” [Epoxy equivalent 200 from Nippon Kayaku Co., Ltd.] and propylene 245 parts of glycol monomethyl ether acetate was charged and heated to 110 ° C. to dissolve uniformly. Subsequently, 76 parts of acrylic acid, 2 parts of triphenylphosphine and 0.2 part of p-methoxyphenol were charged and reacted at 110 ° C. for 10 hours.
The reaction product was further charged with 91 parts of tetrahydrophthalic anhydride, reacted at 90 ° C. for 5 hours, and then diluted with propylene glycol monomethyl ether acetate so that the resin content was 50% by weight. A 50% solution of a cresol novolac type epoxy resin (A-1) was obtained as an epoxy resin having the following.
The acid value in terms of solid content of this epoxy resin was 88.4. The number average molecular weight by GPC was 2,200.

Production Example 2 [Production of Resin (A-2) Having Radical Polymerizable Group]
A glass flask equipped with a heating / cooling / stirring device, a reflux condenser, and a nitrogen introduction tube was charged with 90 parts of styrene, 10 parts of methyl methacrylate, 30 parts of methacrylic acid, and 327 parts of propylene glycol monomethyl ether acetate. After substituting the gas phase part in the system with nitrogen, 38 parts of a solution prepared by dissolving 8 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) in 30 parts of propylene glycol monomethyl ether acetate were added, and 90 ° C. And further reacted at the same temperature for 4 hours. Further, 15 parts of glycidyl methacrylate and 1 part of triethylamine were added to the obtained solution and reacted at 90 ° C. for 6 hours. As an acrylic resin having a (meth) acryloyl group and a carboxyl group, an acrylic resin (A-2) 30 % Solution was obtained.
The acid value in terms of solid content of this acrylic resin was 96.1. The number average molecular weight by GPC was 4,500.

Production Example 3 [Production of Resin (A-3) Having Radical Polymerizable Group]
In a glass flask equipped with a heating / cooling / stirring device, a reflux condenser, and a nitrogen introduction tube, 191 parts of a copolymer of styrene and maleic anhydride (SMA-EF40, manufactured by Sartomer), 102 parts of hydroxyethyl methacrylate and propylene glycol 700 parts of monomethyl ether acetate was charged. After replacing the gas phase part in the system with nitrogen, 7 parts of triethylamine was added, heated to 90 ° C., and further reacted at the same temperature for 8 hours. As an acrylic resin having a (meth) acryloyl group and a carboxyl group, A 30% solution of resin (A-3) was obtained.
The acid value in terms of solid content of this acrylic resin was 98. The number average molecular weight by GPC was 5,500.

Production Example 4 [Production of Resin (A-4) Having Radical Polymerizable Group]
A glass flask equipped with a heating / cooling / stirring device, a reflux condenser, and a nitrogen introduction tube was charged with 6 parts of methyl methacrylate, 70 parts of methacrylic acid, 172 parts of cyclohexyl methacrylate and 454 parts of diethylene glycol dimethyl ether. After replacing the gas phase in the system with nitrogen, 175 parts of a solution prepared by dissolving 16 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) in 159 parts of diethylene glycol dimethyl ether was added and heated to 90 ° C. The mixture was further reacted at the same temperature for 4 hours. Further, 31 parts of glycidyl methacrylate, 10 parts of triethylamine, and 82 parts of propylene glycol monomethyl ether acetate were added to the resulting solution and reacted at 90 ° C. for 6 hours to obtain an acrylic resin having a (meth) acryloyl group and a carboxyl group. A 30% solution of resin (A-4) was obtained.
The acid value in terms of solid content of this acrylic resin was 112.9. The number average molecular weight by GPC was 4,700.

Production Example 5 [Production of Compound (C-2) Having Hydrolyzable Alkoxy Group]
In a glass flask equipped with a heating / cooling / stirring device, a reflux condenser, a dropping funnel and a nitrogen introduction tube, 46 parts (0.2 mol part) of 3-acryloyloxypropyltrimethoxysilane, 160 parts of diphenyldimethoxysilane (0 .65 mol part), 45 g (2.5 mol part) of ion-exchanged water and 0.1 part (0.001 mol part) of oxalic acid, and heated and stirred at 60 ° C. for 6 hours. The methanol by-produced by hydrolysis was removed under reduced pressure over 2 hours to obtain acrylic-modified alkoxypolysiloxane (C-2) (number average molecular weight: 2,100).

Production Example 6 [Production of Titanium Oxide Dispersion (E-1)]
A SUS flask equipped with a stirrer was charged with 500 parts of propylene glycol monomethyl ether acetate and 80 parts of polyacrylic acid as a dispersing agent and homogenized. Here, 420 parts of titanium oxide (trade name: JR-403, average particle size: 0.21 um, manufactured by Teika Co., Ltd.) whose surface was treated with an inorganic material were charged and stirred and dispersed. This dispersed liquid was transferred to a 250 mL plastic container, and further glass beads having a particle diameter of 1 mm were charged therein and dispersed for 1 hour with a paint shaker. After completion of the dispersion, the glass beads were removed by filtration through 300 mesh to obtain a 50% dispersion of titanium oxide (E-1).

Production Example 7 [Production of Titanium Oxide (E-2) Dispersion]
Similar to Production Example 7 except that the titanium oxide of Production Example 7 was changed from a surface inorganic treatment product to a surface organic treatment product (trade name: D-2667, average particle size: 0.26 um, manufactured by Sakai Chemical Co., Ltd.). In this way, a 50% dispersion (E-2) of titanium oxide was obtained.

Comparative Production Example 1 [Production of Resin (A′-1) Having Radical Polymerizable Group]
190 parts of styrene, 70 parts of methacrylic acid, and 670 parts of propylene glycol monomethyl ether acetate were charged into a glass flask equipped with a heating / cooling / stirring device, a reflux condenser, and a nitrogen introduction tube. After replacing the gas phase part in the system with nitrogen, 27 parts of a solution in which 2 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in 25 parts of propylene glycol monomethyl ether acetate were added, and 90 ° C. And further reacted at the same temperature for 4 hours. Further, 36 parts of glycidyl methacrylate and 7 parts of triethylamine were added to the obtained solution and reacted at 90 ° C. for 6 hours. As an acrylic resin having a (meth) acryloyl group and a carboxyl group, an acrylic resin (A′-1) A 30% solution was obtained.
The acid value in terms of solid content of this acrylic resin was 80. The number average molecular weight by GPC was 70,000.

Examples 1-7 and Comparative Examples 1-4
In accordance with the number of parts shown in Table 1, the solution of (A), (B), (C) and (D) and, if necessary, (F), (G) and / or (H) are charged into a glass container, and uniformly After stirring until the same, the dispersion of (E) and the solvent (J) (propylene glycol monomethyl ether acetate) were charged at the same time to obtain a uniform dispersion, and the photosensitive resin compositions of Examples 1 to 7 and Comparative Examples 1 to 4 were used. Got.

The details of the chemicals in Table 1 are as follows.
(B-1): “Neomer DA-600” (dipentaerythritol pentaacrylate: manufactured by Sanyo Chemical Industries, Ltd.)
(B-2): “Neomer EA-300” (pentaerythritol tetraacrylate: manufactured by Sanyo Chemical Industries, Ltd.)
(C-1): Methacryl-modified alkoxysilane ("KBM-503": manufactured by Shin-Etsu Chemical Co., Ltd.)
(D-1): “Irgacure 819” (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide: manufactured by BASF, extinction coefficient at 405 nm: 899)
(D-2): “Irgacure 907” (2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one: manufactured by BASF)
(D-3): “Kayacure DETX-S” (2,4-diethylthioxanthone: manufactured by Nippon Kayaku Co., Ltd.)
(F-1): “Light acrylate P-1A” (2-acryloyloxyethyl acid phosphate: manufactured by Kyoeisha Chemical Co., Ltd.)
(G-1): Polyether-modified polydimethylsiloxane (“KF-352A”: manufactured by Shin-Etsu Chemical Co., Ltd.)
(G-2): Polyether-modified fluorine compound (“Megafac TF-2066” manufactured by DIC Corporation)
(H-1): 2,6-di-t-butyl-4-methylphenol (“BHT”: manufactured by Tokyo Chemical Industry Co., Ltd.)

The performance evaluation method will be described below.
[Production of cured plate]
The photosensitive resin composition was applied onto a 10 cm × 10 cm square glass substrate with an applicator and dried to form a coating film having a dry film thickness of 5 μm. This coating film was heated on a hot plate at 80 ° C. for 3 minutes.
The obtained coating film was irradiated with light from an ultrahigh pressure mercury lamp at 100 mJ / cm ² .

[Evaluation of adhesion]
In accordance with JIS K 5600-5-6, the cured product is cut into a 1 mm width with a cutter knife so as to form 100 (10 × 10) masses, and the resin adhesion is measured.
The measurement result is expressed as “the grid remaining on the base film after the test / 100”.
○: The squares remaining on the film after the test are 100/100
X: The grid remaining on the film after the test was 99/100 or less

[Evaluation of reflectance]
Using the spectrocolorimeter (CM3700d, light source C) used for measuring the object color in accordance with JIS Z 8722, the above cured product was measured with a reflectance of wavelength: 650 nm as a total reflectance.
◎: Reflectance is 85% or more ○: Reflectance is 80% or more and less than 85% △: Reflectance is 70% or more and less than 80% ×: Reflectance is less than 70%

The photosensitive resin compositions of Examples 1 to 7 of the present invention are excellent in both adhesiveness and reflectance as shown in Table 1.
On the other hand, the comparative example 1 which does not use resin (A) which has a radically polymerizable group, the comparative example 2 which does not use the compound (C) which has a hydrolyzable alkoxyl group, and resin (A) instead of Comparative Example 4 using a resin having a number average molecular weight exceeding 50,000 does not satisfy the adhesion. Moreover, the comparative example 3 which does not use titanium oxide (E) does not satisfy a reflectance.

  Since the photosensitive resin composition of this invention is excellent in the reflectance after hardening and the adhesiveness with respect to a glass substrate, it can be used conveniently as a reflecting plate of a display.

Claims (7)

Resin (A) having a radical polymerizable group having a number average molecular weight of 2,200 to 5,500 and an acid value (unit: KOHmg / g) of 80 to 150 , two or more radical polymerizable groups other than the above (A) A compound (B) having a group, a compound (C) having a hydrolyzable alkoxy group, a photopolymerization initiator (D) and titanium oxide (E) as essential components, and having the hydrolyzable alkoxy group The photosensitive resin composition whose compound (C) is a siloxane compound which is a silane compound represented by the following general formula (1) or a condensate thereof.

[Wherein R ¹ is a (meth) acryloyloxyalkyl group having 1 to 6 carbon atoms in the alkyl group, a glycidoxyalkyl group having 1 to 6 carbon atoms in the alkyl group, or a carbon number in the alkyl group. 1 represents one or more organic groups selected from the group consisting of a mercaptoalkyl group having 1 to 6 and an aminoalkyl group having 1 to 6 carbon atoms in the alkyl group, and R ² represents a fatty acid having 1 to 12 carbon atoms. Represents a saturated aromatic hydrocarbon group or an aromatic hydrocarbon group having 6 to 12 carbon atoms, R ³ represents an alkyl group having 1 to 4 carbon atoms, and m is 0 or 1. ]   The photosensitive resin composition according to claim 1, wherein the resin (A) having a radical polymerizable group has a carboxyl group.   The photosensitive resin composition according to claim 1 or 2, wherein the compound (B) having two or more radically polymerizable groups is a compound having a (meth) acryloyl group.   4. The method according to claim 1, wherein the resin (A) is a combination of an epoxy resin (A1) having a radical polymerizable group and a (meth) acrylic resin (A2) having a radical polymerizable group. The photosensitive resin composition as described.   The photosensitive resin composition according to claim 1, wherein at least one of the photopolymerization initiators (D) is an initiator having absorbance at a wavelength of 400 nm or more.   The photosensitive resin composition according to any one of claims 1 to 5, wherein a weight ratio of titanium oxide (E) to a solid content in the photosensitive resin composition is 30 to 90% by weight. The weight ratio of the compound (C) which has a hydrolyzable alkoxy group with respect to the weight of the solid content in the photosensitive resin composition contains 0.1 to 20 weight%, The description of any one of Claims 1-6 Photosensitive resin composition.