TWI480685B - A photosensitive resin composition and a liquid crystal panel - Google Patents

Description

Photosensitive resin composition and liquid crystal panel

The present invention relates to a photosensitive resin composition and a liquid crystal panel, and more particularly to a photosensitive resin composition suitable for a spacer provided between two substrates of a liquid crystal panel, and A liquid crystal panel of a spacer formed of a photosensitive resin composition.

In the liquid crystal panel of the liquid crystal display device, since the sandwich structure in which the liquid crystal material is sandwiched by the transparent substrate such as two glass substrates is used, it is necessary to form a spacer between the two substrates under the liquid crystal material.

Conventionally, in order to form a spacer, a method of dispersing beads forming a spacer over the entire substrate is used, but only on the pixel display portion; beads are also attached, and the contrast of the image or the display image quality is lowered. . Therefore, in recent years, various methods for forming the spacer by a photosensitive resin composition have been proposed (see Patent Documents 1, 2, etc.). In this method, a photosensitive resin composition is applied onto a substrate, exposed to light through a predetermined mask, and developed to form spacers such as dots, and spacers can be formed only in a predetermined portion other than the pixel display portion. .

[Practical Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2006-184841

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2006-308961

Here, in order to prevent plastic deformation or breakage of the spacer due to excessive load of the liquid crystal panel, it is necessary to have sufficient fracture strength of the formed spacer. Therefore, an alkali-soluble resin having a constituent unit derived from an epoxy group-containing unsaturated compound such as glycidyl methacrylate is usually used as the resin contained in the photosensitive resin composition.

However, as a result of further intensive review, the inventors of the present invention found that the ratio of the constituent units derived from glycidyl methacrylate or the like in the case of improving the breaking strength is, for example, 71% by mass or more, the breakpoint at the time of development. (BP; the time when the unexposed portion is completely dissolved) becomes extremely short, and development is not easily performed properly. Further, it is understood that the shape of the spacer is deteriorated at the same time, and the adhesion to the substrate is lowered.

The present invention is directed to a photosensitive resin composition having a suitable developability and capable of forming a spacer having a good shape or adhesion to a substrate, and having a photosensitive resin composition. The liquid crystal panel of the spacer formed by the object is for the purpose.

In order to solve the above problems, the inventors of the present invention have conducted in-depth review. As a result, it has been found that by using a constituent unit derived from an unsaturated carboxylic acid and a constituent unit derived from an epoxy group-containing unsaturated compound having no alicyclic group, and an unsaturated group containing an alicyclic epoxy group The above-mentioned problem can be solved by the constituent unit derived from the compound or the alkali-soluble resin derived from the constituent unit derived from the unsaturated compound containing an alicyclic group, and the present invention has been completed. Specifically, the present invention provides the following.

The first aspect of the present invention relates to a photosensitive resin composition containing a photosensitive resin composition of an alkali-soluble resin (A), a photopolymerizable monomer (B), and a photopolymerization initiator (C), which are characterized The alkali-soluble resin (A) is a constituent unit (a2) having a constituent unit (a1) derived from an unsaturated carboxylic acid, an unsaturated compound containing an epoxy group having no alicyclic group, and The constituent unit (a3) derived from the unsaturated compound containing an alicyclic epoxy group, and the total ratio of the ratio of the constituent unit (a2) to the constituent unit (a3) is 71% by mass or more.

The second aspect of the present invention relates to a photosensitive resin composition containing a photosensitive resin composition of an alkali-soluble resin (A), a photopolymerizable monomer (B), and a photopolymerization initiator (C), which is characterized by The alkali-soluble resin (A) is a constituent unit (a2) having a constituent unit (a1) derived from an unsaturated carboxylic acid, an unsaturated compound containing an epoxy group having no alicyclic group, and The constituent unit (a4) derived from the unsaturated compound containing an alicyclic group, and the ratio of the above-mentioned constituent unit (a2) is 71% by mass or more.

A third aspect of the present invention relates to a liquid crystal panel characterized by comprising a spacer formed of the photosensitive resin composition of the present invention.

[Effect of the invention]

According to the present invention, it is possible to provide a photosensitive resin composition having a suitable developability and capable of forming a spacer having a good shape or adhesion to a substrate, and a liquid crystal having a spacer formed of the photosensitive resin composition. panel.

[In order to implement the invention] <<Photosensitive Resin Composition>>

The photosensitive resin composition of the present invention contains at least an alkali-soluble resin (A), a photopolymerizable monomer (B), and a photopolymerization initiator (C). Each component contained in the photosensitive resin composition of the present invention will be described below.

<alkali soluble resin (A)>

The alkali-soluble resin refers to a resin film having a film thickness of 1 μm formed on a substrate by a resin solution having a resin concentration of 20% by mass (solvent: propylene glycol monomethyl ether acetate), and 2.38 mass% of tetramethylammonium hydroxide (TMAH). When immersed in an aqueous solution for 1 minute, the film thickness is 0.01 μm or more.

The alkali-soluble resin (A) (hereinafter also referred to as "(A) component)) contained in the photosensitive resin composition of the present invention has a constituent unit (a1) derived from an unsaturated carboxylic acid, and contains no a constituent unit (a2) derived from an alicyclic group-containing epoxy group-containing unsaturated compound, and a constituent unit (a3) derived from an alicyclic epoxy group-containing unsaturated compound (hereinafter the resin is also referred to as " (A1) Resin") is a constituent unit (a4) derived from the above-mentioned constituent unit (a1), the above-mentioned constituent unit (a2), and an unsaturated compound containing an alicyclic group (hereinafter, the resin is also referred to as "( A2) Resin"). In the following, the sequence describes various situations related to these.

((A1) resin)

(A1) The resin has at least the above-mentioned constituent unit (a1), the above-mentioned constituent unit (a2), and the above-mentioned constituent unit (a3).

An unsaturated carboxylic acid derived from the constituent unit (a1), for example, a monocarboxylic acid such as (meth)acrylic acid or crotonic acid; maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid Dicarboxylic acids; anhydrides of such dicarboxylic acids, and the like. Among these, (meth)acrylic acid and maleic anhydride are preferable in terms of copolymerization reactivity, alkali solubility of the obtained resin, and easy availability. These unsaturated carboxylic acids may be used singly or in combination of two or more kinds.

An epoxy group-unsaturated compound having no alicyclic group, such as glycidyl (meth)acrylate or 2-methylglycidyl (meth)acrylate, when the constituent unit (a2) is derivatized, (meth)acrylic acid epoxy alkyl esters such as 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl (meth)acrylate; α-ethyl acrylate propylene Alpha-alkyl acrylate alkyl acrylate such as ester, α-n-propyl propylene acrylate, α-n-butyl butyl acrylate, α-ethyl acrylate 6,7-epoxyheptyl ester Classes, etc. Among these, in terms of copolymerization reactivity, resin strength after curing, etc., glycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, and (methyl) The 6,7-epoxyheptyl acrylate is preferred. These epoxy group-containing unsaturated compounds having no alicyclic group may be used singly or in combination of two or more kinds.

The alicyclic epoxy group-containing unsaturated compound in the case where the constituent unit (a3) is derivatized is not particularly limited as long as it is an unsaturated compound having an alicyclic epoxy group. The alicyclic group constituting the alicyclic epoxy group may be a single ring or a polycyclic ring. A monocyclic alicyclic group such as a cyclopentyl group, a cyclohexyl group or the like. Further, a polycyclic alicyclic group is, for example, a norbornyl group, an isobornyl group, a tricyclodecyl group, a tricyclodecyl group, a tetracyclododecyl group or the like.

Specifically, the alicyclic epoxy group-containing unsaturated compound is, for example, a compound represented by the following formulas (a3-1) to (a3-15). In the above, when the developability is appropriate, the compounds represented by the following formulas (a3-1) to (a3-5) are preferable, and the following formulas (a3-1) to (a3-3) are used. The compounds shown are preferred.

【化1】

[Chemical 2]

[化3]

In the above formula, R ¹¹ represents a hydrogen atom or a methyl group, R ¹² represents a divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms, R ¹³ represents a divalent hydrocarbon group having 1 to 10 carbon atoms, and n represents 0. An integer of ~10. R ¹² is a linear or branched alkyl group such as methylene, ethyl, propyl, tetramethylene, ethylethyl, pentamethylene or hexamethylene. R ¹³ such as methylene, ethyl, propyl, tetramethylene, ethylethyl, pentamethylene, hexamethylene, phenylene, cyclohexyl, -CH ₂ -Ph-CH ₂ - (Ph represents a phenylene group) is preferred.

In addition, the (A1) resin may have a total amount of the ratio of the ratio of the constituent unit (a2) to the constituent unit (a3) of 71% by mass or more, and may have the following constituent unit (a4). The effect of the present invention can be improved by combining the constituent units (a4).

Further, the (A1) resin may have other constituent units other than the above-described constituent units (a1), (a2), (a3), and (a4). The compound in the case where the other constituent unit is derived is, for example, a (meth) acrylate, a (meth) acrylamide, an allyl compound, a vinyl ether, a vinyl ester, or a styrene. These compounds may be used alone or in combination of two or more.

(Meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, amyl (meth) acrylate, 3-octyl (meth) acrylate Linear or branched alkyl (meth)acrylate; ethyl (meth)acrylate, 2,2-dimethylhydroxypropyl (meth)acrylate, 2-(meth)acrylate Hydroxyethyl ester, trimethylolpropane mono(meth)acrylate, benzyl (meth)acrylate, decyl (meth)acrylate, and the like.

(Meth) acrylamides such as (meth) acrylamide, N-alkyl (meth) acrylamide, N-aryl (meth) acrylamide, N, N-dialkyl (A Acrylamide, N,N-aryl(meth)acrylamide, N-methyl-N-phenyl(meth)acrylamide, N-hydroxyethyl-N-methyl (methyl ) acrylamide and the like.

Allyl compound such as allyl acetate, allyl hexanoate, allyl octanoate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, acetaminoacetic acid Allyl esters such as allyl ester and allyl lactate; allyloxyethanol and the like.

Vinyl ethers such as hexyl vinyl ether, octyl vinyl ether, mercapto vinyl ether, ethylhexyl vinyl ether, methoxy ethyl vinyl ether, ethoxyethyl vinyl ether, ethyl vinyl chloride, 1-methyl Base-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylamine An alkyl vinyl ether such as ethyl ethyl vinyl ether, butyl amino ethyl vinyl ether, benzyl vinyl ether or tetrahydrofurfuryl vinyl ether; vinyl phenyl ether, vinyl toluene ether, vinyl phenyl chloride A vinyl aryl ether such as vinyl-2,4-dichlorophenyl ether, vinyl naphthyl ether or vinyl anthracene.

Vinyl esters such as vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl acetate, vinyl valerate, vinyl hexanoate, vinyl acetate, vinyl acetate Ester, methoxyvinyl acetate, butoxy vinyl acetate, vinyl phenyl acetate, vinyl acetate, vinyl laurate, vinyl β-phenylbutyrate, vinyl benzoate, water Vinyl acetate, vinyl benzoate, vinyl benzoate, vinyl naphthate, and the like.

Styrenes such as styrene; methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, butyl styrene, hexyl styrene, An alkane such as cyclohexylstyrene, mercaptostyrene, benzyl styrene, methyl styrene chloride, methyl styrene trifluoride, ethoxymethyl styrene, ethoxymethyl methene styrene Alkoxystyrene, methoxystyrene, 4-methoxy-3-methylstyrene, dimethoxystyrene, etc.; styrene chloride, styrene dichloride, trichloro Styrene, styrene tetrachloride, styrene pentachloride, styrene bromide, styrene dibromide, styrene iodide, styrene fluoride, styrene trifluoride, 2-bromo-4-tri Halogenated styrene such as fluorinated methyl styrene or 4-fluoro-3-trifluoromethyl styrene.

The ratio of the above-mentioned constituent unit (a1) in the resin (A1) is preferably 5 to 29% by mass, more preferably 10 to 25% by mass.

Further, the total ratio of the ratio of the constituent unit (a2) in the resin (A1) to the ratio of the constituent unit (a3) is 71% by mass or more, preferably 71 to 95% by mass, and more preferably 75 to 5% by weight. 90% by mass. The ratio of the constituent unit (a2) is preferably from 10 to 70% by mass, more preferably from 20 to 45% by mass. Further, the ratio of the constituent unit (a3) is preferably 20 to 65 mass%, more preferably 30 to 50 mass%. By setting the ratio of the constituent unit (a3) within the above range, the developability can be made appropriate, and the specific dielectric constant of the cured product can be lowered.

Further, the ratio of the above-mentioned constituent unit (a4) in the (A1) resin is preferably from 1 to 15% by mass, more preferably from 3 to 10% by mass.

Further, the ratio of the other constituent units in the (A1) resin is preferably from 0 to 10% by mass, more preferably from 0 to 5% by mass.

When the ratio of each constituent unit is within the above range, the developability of the photosensitive resin composition can be made appropriate, and the shape or breaking strength of the cured product and the adhesion to the substrate can be improved.

(A1) Mass average molecular weight of the resin (Mw: gel permeation chromatography (GPC)), measured value in terms of styrene. The same in the present specification) is preferably from 2,000 to 50,000, more preferably from 5,000 to 30,000. By the above range, the film forming ability of the photosensitive resin composition and the balance of the developability after exposure tend to be easily obtained.

(A1) When the resin has a constituent unit other than the above constituent units (a1), (a2), and (a3), the (A1) resin can be produced by a conventional radical polymerization method. In other words, each compound derived from each constituent unit and a conventional radical polymerization initiator can be dissolved in a polymerization solvent, and then heated and stirred to be produced.

Further, when the (A1) resin does not have a constituent unit other than the above-mentioned constituent units (a1), (a2), and (a3), the general radical polymerization method is such that the carboxyl group and the constituent unit (a2) of the constituent unit (a1) are The epoxy group of (a3) is reacted and gelled.

Therefore, in the above case, the reaction mixture is prepared by first reacting an unsaturated carboxylic acid with a specific reactive compound (reaction step), and then the reaction mixture is not reacted with an epoxy group having no alicyclic group. The saturated compound and the unsaturated compound containing an alicyclic epoxy group are subjected to copolymerization (polymerization step) to produce a resin (A1). Depending on the requirements, it is also possible to carry out the refining and rinsing treatment (refining step).

First, the reaction step is carried out by adding an unsaturated carboxylic acid and at least one compound selected from the group consisting of the compounds (reactive compounds) represented by the following formulas (1) to (3) to a suitable reaction vessel such as a flask. The mixture was heated and stirred to prepare a reaction mixture.

【化4】

R ¹ -O-R ³ -O-R ² (1)

(wherein R ¹ and R ² each independently represent an alkyl group having 1 to 4 carbon atoms; and R ³ represents a linear or branched hydrocarbon group having 1 to 4 carbon atoms which may also contain an oxygen atom)

【化5】

(wherein R ⁴ and R ⁵ each represent an independent alkyl group having 1 to 4 carbon atoms)

【化6】

(wherein R ⁶ and R ⁷ each independently represent an alkyl group having 1 to 4 carbon atoms, and R ⁸ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms)

a compound represented by the above formula (1), for example, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,2-dipropoxyethane, 1,2-di Butoxyethane, diethoxymethane, dipropoxymethane, dibutoxymethane, 1,1-dimethoxypropane, 1,1-diethoxypropane, 1,1-dipropyl Oxypropane, 1,1-dibutoxypropane, 2,2-dimethoxypropane, 2,2-diethoxypropane, 2,2-dipropoxypropane, 2,2-dibutyl Oxypropane, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, and the like.

a compound represented by the above formula (2), for example, 2,5-dimethoxytetrahydrofuran, 2,5-diethoxytetrahydrofuran, 2,5-dipropoxytetrahydrofuran, 2,5-dibutoxy Tetrahydrofuran and the like.

a compound represented by the above formula (3), for example, 3,4-dimethoxytoluene, 3,4-diethoxytoluene, 3,4-dipropoxytoluene, 3,4-dibutoxy Toluene, 1,2-dimethoxybenzene, 1,2-diethoxybenzene, 1,2-dipropoxybenzene, 1,2-dibutoxybenzene, and the like.

Among these reactive compounds, in terms of reactivity with an unsaturated carboxylic acid, diethoxymethane, 1,2-dimethoxyethane, 1,2-diethoxyethane, Diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, 2,5-dimethoxytetrahydrofuran, 1,1-diethoxypropane, and 2,2-diethoxypropane are preferred. These reactive compounds may be used singly or in combination of two or more kinds.

The molar ratio of the unsaturated carboxylic acid to the reactive compound is not particularly limited, and is preferably from 1:0.5 to 1:3, more preferably from 1:0.8 to 1:2. Further, the reaction temperature is preferably 60 to 150 ° C, more preferably 80 to 120 ° C. The reaction time is preferably from 10 minutes to 10 hours, more preferably from 30 minutes to 5 hours.

Next, the polymerization step is carried out by dissolving the reaction mixture obtained in the reaction step with an epoxy group-containing unsaturated compound having no alicyclic group and an alicyclic epoxy group-containing unsaturated compound in a conventional radical polymerization. After the initiator and the polymerization solvent are heated and stirred, a copolymer is obtained.

Finally, the purification step is performed by, for example, washing treatment using a poor solvent or the like to remove the residue.

The content of the resin (A1) is preferably 40 to 230% by mass, more preferably 60 to 220% by mass, and 70 to 215% by mass, based on the content of the photopolymerizable monomer (B). optimal.

((A2) resin)

The resin (A2) has at least the above-mentioned constituent unit (a1), the above-mentioned constituent unit (a2), and the above-mentioned constituent unit (a4). The compound in the case where the constituent units (a1) and (a2) are derivatized is the same as in the case of the (A1) resin, and thus the description thereof is omitted. The resin (A2) may have other constituent units other than the constituent units (a1), (a2), and (a4). The other constituent units described above are, for example, the same constituent units as the other constituent units of the resin (A1).

The alicyclic group-containing unsaturated compound in the case where the constituent unit (a4) is derivatized is not particularly limited as long as it is an unsaturated compound having an alicyclic epoxy group. The alicyclic group may be a single ring or a polycyclic ring. A monocyclic alicyclic group such as a cyclopentyl group, a cyclohexyl group or the like. Further, a polycyclic alicyclic group such as an adamantyl group, a norbornyl group, an isobornyl group, a tricyclodecyl group, a tricyclodecyl group, a tetracyclododecyl group or the like.

Specifically, the alicyclic epoxy group-containing unsaturated compound is, for example, a compound represented by the following formulas (a4-1) to (a4-7). In the above, in order to make the developability suitable, the compounds represented by the following formulas (a4-3) to (a4-8) are preferred, and the following formulas (a4-3) and (a4-4) are used. The compounds shown are preferred.

【化7】

【化8】

In the above formula, R ²¹ represents a hydrogen atom or a methyl group, R ²² represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms, and R ²³ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. . R ²² is a single bond, a linear or branched alkyl group, such as methylene, ethyl, propyl, tetramethylene, ethyl ethyl, pentamethylene, hexamethylene good. R ^{23 is} preferably a methyl group or an ethyl group.

The ratio of the above-mentioned constituent unit (a1) in the resin (A2) is preferably 3 to 25% by mass, more preferably 5 to 25% by mass.

Further, the ratio of the above-mentioned constituent unit (a2) in the (A2) resin is 71% by mass or more, preferably 71 to 95% by mass, and more preferably 75 to 90% by mass.

Further, the ratio of the above-mentioned constituent unit (a4) in the (A2) resin is preferably 1 to 25% by mass, more preferably 3 to 20% by mass, and most preferably 5 to 15% by mass. By setting the ratio of the constituent unit (a4) within the above range, the developability can be made appropriate, and the specific dielectric constant of the cured product can be lowered.

Further, the ratio of the other constituent units in the (A2) resin is preferably from 0 to 10% by mass, more preferably from 0 to 5% by mass.

When the ratio of each constituent unit is within the above range, the developability of the photosensitive resin composition can be made appropriate, and the shape or breaking strength of the cured product and the adhesion to the substrate can be improved.

The mass average molecular weight of the resin (A2) is preferably from 2,000 to 50,000, more preferably from 5,000 to 30,000. In the above range, the film forming ability of the photosensitive resin composition and the balance of the developability after exposure tend to be easily obtained.

The (A2) resin can be produced by a conventional radical polymerization method. In other words, each compound derived from each constituent unit and a conventional radical polymerization initiator can be dissolved in a polymerization solvent, and then heated and stirred to be produced.

The content of the resin (A2) is preferably 40 to 230% by mass, more preferably 60 to 220% by mass, and 70 to 215% by mass, based on the content of the photopolymerizable monomer (B). optimal.

Further, the component (A) may contain other conventional alkali-soluble resins in addition to the (A1) resin or the (A2) resin. In this case, in all the constituent units of the component (A), the proportion of the constituent unit having an epoxy group is preferably 50% by mass or more.

Further, the content of the component (A) is preferably from 40 to 85% by mass, more preferably from 45 to 75% by mass, based on the solid content of the photosensitive resin composition. Within the above range, there is a tendency that the balance of developability can be easily obtained.

<Photopolymerizable monomer (B)>

The photopolymerizable monomer (B) (hereinafter also referred to as "(B) component)) contained in the photosensitive resin composition of the present invention is preferably a monomer having an ethylenically unsaturated group. The monomer having an ethylenically unsaturated group is a monofunctional monomer and a polyfunctional monomer.

Monofunctional monomers such as (meth) acrylamide, hydroxymethyl (meth) acrylamide, methoxymethyl (meth) acrylamide, ethoxymethyl (meth) acrylamide, Propyloxymethyl (meth) acrylamide, butoxymethoxymethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-hydroxymethyl (methyl) Acrylamide, (meth)acrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, crotonic acid, 2-propenylamine-2 -methylpropanesulfonic acid, 3-butylacrylamide, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethyl (meth)acrylate Hexyl hexyl ester, cyclohexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (methyl) 2-phenoxy-2-hydroxypropyl acrylate, 2-(methyl)propenyloxy-2-hydroxypropyl phthalate, glycerol mono(meth)acrylate, (methyl) Tetrahydrofurfuryl acrylate, dimethyl (meth) acrylate, glycidyl (meth) acrylate, (meth) propylene 2,2,2-trifluoroethyl acrylate, (meth) acrylate, 2,2,3,3-tetrafluoro-propyl, semi-phthalic acid derivative of (meth) acrylate. These monofunctional monomers may be used singly or in combination of two or more kinds.

Further, polyfunctional monomers such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate Polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl bis(meth)acrylate, 1,6-hexanediol di(meth)acrylate, three ( Trimethylolpropane methyl methacrylate, glycerol di(meth) acrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, di(meth)acrylic acid Pentaerythritol ester, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 2,2-bis(4-( Methyl)propenyloxydiethoxyphenyl)propane, 2,2-bis(4-(methyl)propenyloxypolyethoxyphenyl)propane, 2-hydroxy-3-(methyl) ) acryloxypropyl (meth) acrylate, ethylene glycol diglycidyl di(meth) acrylate, diethylene glycol diglycidyl di(methyl) propyl Ethyl ester, diglycidyl phthalate di(meth) acrylate, glycerol triacrylate, glycerol polyglycidyl ether poly(meth) acrylate, urethane (A Reaction of 2-hydroxyethyl (meth) acrylate, such as methacrylate (i.e., metriphenyl diisocyanate), trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, etc. a polyfunctional monomer such as methyl bis(methyl) acrylamide, (meth) acrylamide methyl ether, a condensate of a polyol and N-methylol (meth) acrylamide, or tripropylene Alkyl acetal and the like. These polyfunctional monomers can be used singly or in combination of two or more kinds.

In the monomer having an ethylenically unsaturated group, the adhesiveness of the photosensitive resin composition to the substrate and the breaking strength of the photosensitive resin composition after curing are three or more functional polyfunctional monomers. Preferably, a polyfunctional monomer having 6 or more functional groups is more preferable.

The content of the component (B) is preferably from 5 to 50% by mass, more preferably from 10 to 40% by mass, based on the solid content of the photosensitive resin composition. By being within the above range, sensitivity can be easily obtained. The tendency to balance the developability and resolution.

<Photopolymerization initiator (C)>

The photopolymerization initiator (C) (hereinafter also referred to as "(C) component)) contained in the photosensitive resin composition of the present invention is not particularly limited, and a conventional photopolymerization initiator can be used.

Specifically, a photopolymerization initiator such as 1-hydroxycyclohexyl benzophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)benzene 2-hydroxy-2-methyl-1-propan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4 -dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, bis (4- Dimethylaminophenyl)one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropan-1-one, 2-benzyl-2-ene Methylamino-1-(4-morpholinylphenyl)-butan-1-one, ethyl ketone, 1-[9-ethyl-6-(2-methylbenzhydryl)-9H- Oxazol-3-yl], 1-(o-ethylindenyl), 2,4,6-trimethylbenzimidyldiphenylphosphine oxide, 4-benzylidene-4'-methyl Dimethyl sulfide, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, 4-dimethylaminobenzoic acid Ester, 4-dimethylamino-2-ethylhexylbenzoic acid, 4-dimethylamino-2-isopentylbenzoic acid, benzyl-β-methoxyethyl acetal, benzene Methyl dimethyl acetal, 1-phenyl-1,2-propanedione-2-(o-ethoxy carbonyl肟, methyl o-benzylidene benzoate, 2,4-diethyl thioxanthone, 2-thioxanthone chloride, 2,4-dimethylthioxanthone, 1-chloro-4- Propoxy thioxanthone, thioxanthene, 2-chlorothioxanthene, 2,4-diethylthioxanthene, 2-methylthioxanthene, 2-isopropylthioxanthene, 2-ethylhydrazine, eight Methyl hydrazine, 1,2-benzopyrene, 2,3-diphenyl fluorene, azobisisobutyronitrile, benzoyl peroxide, cumene peroxide, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)-imidazolyl dimer, diphenyl Ketone, 2-benzoic benzophenone, p,p'-bisdimethylaminobenzophenone, 4,4'-bisdiethylaminobenzophenone, 4,4'-dichloro Benzophenone, 3,3-dimethyl-4-methoxybenzophenone, benzyl, benzoin, benzoin methyl ether, benzoin ether, benzoin isopropyl ether, Benzophene n-butyl ether, benzoin isobutyl ether, benzoin butane, acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylamino Phenylacetone, acetophenone dichloride, acetophenone trichloride, p-tert-butylacetophenone, p-dimethyl Amino acetophenone, p-tert 3-butyl acetophenone, p-tert 3-butyl acetophenone, α,α-dichloro-4-phenoxyacetophenone, Thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, dibenzocycloheptanone, pentyl-4-dimethylaminobenzoate, 9-phenyl acridine, 1,7-bis-(9-acridinyl)heptane, 1,5-bis(9-acridinyl)pentane, 1,3-bis-(9-acridinyl)propane, p-methoxy Triazine, 2,4,6-gin (methyl chloride)-s-triazine, 2-methyl-4,6-bis(methyl chloride)-s-triazine, 2-[ 2-(5-methylfuran-2-yl)ethylidene]-4,6-bis(methyl chloride)-s-triazine, 2-[2-(furan-2-yl)-second 4,6-bis(trimethylmethyl)-s-triazine, 2-[2-(4-diethylamino-2-methylphenyl)ethenyl]-4,6 - bis(methyl chloride)-s-triazine, 2-(3,4-dimethoxyphenyl)ethylidene]-4,6-bis(methyl chloride)-s-three Pyrazine, 2-(4-methoxyphenyl)-4,6-bis(methyl chloride)-s-triazine, 2-(4-ethoxystyryl)-4,6-double (methyl chloride)-s-triazine, 2-(4-n-butoxyphenyl)-4,6-bis(methyl chloride)-s-triazine, 2,4-bis- Methyl-6-(3-bromo-4-methoxy)phenyl-s-triazine, 2,4-bis- Methyl-6-(2-bromo-4-methoxy)phenyl-s-triazine chloride, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy Styrylphenyl-s-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)styrylphenyl-s-triazine, and the like. Among these, the use of a fluorene-based photopolymerization initiator is more preferable in terms of sensitivity. These photopolymerization initiators may be used singly or in combination of two or more kinds.

The content of the component (C) is preferably from 0.5 to 30% by mass, more preferably from 1 to 20% by mass, based on the solid content of the photosensitive resin composition. By the above range, sufficient heat resistance and chemical resistance can be obtained, and the coating film forming ability can be improved, and the hardening failure can be suppressed.

Further, a photoinitiator may be combined in the component (C). Photoinitiating aids such as triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, 4-dimethylamino Isoamyl ester, 2-ethylhexyl 4-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, N,N-dimethyl-p-toluidine, 4,4'-double ( Dimethylamino)benzophenone, 9,10-dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 2-ethyl -9,10-diethoxyanthracene, and the like. These photoinitiating aids may be used singly or in combination of two or more kinds.

<Organic Solvent(S)>

In order to improve the applicability and adjust the viscosity, the photosensitive resin composition of the present invention preferably contains an organic solvent (S) (hereinafter also referred to as "(S) component").

Specifically, an organic solvent such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether , diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol (poly)alkylene glycol monoalkane such as mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether Ethers; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), (poly)alkylene glycol monoalkyl ether acetates such as propylene glycol monoethyl ether acetate; diethylene glycol dimethyl ether, diethylene glycol methyl ether, diethylene glycol diethyl ether, tetrahydrofuran, etc. Other ethers; ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone; milk of methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, etc. Acid alkyl esters; ethyl 2-hydroxy-2-methylpropanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3- Ethyl ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3 -methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, N-amyl formate, isoamyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, acetone Other esters such as n-propyl acrylate, methyl acetoxyacetate, ethyl acetoxyacetate, ethyl 2-carbonylbutyrate; aromatic hydrocarbons such as toluene and xylene; N-methylpyrrolidone, N An amide such as N-dimethylformamide or N,N-dimethylacetamide. Among these, an alkanediol monoalkyl ether, an alkylene glycol monoalkyl ether acetate, the above other ethers, an alkyl lactate, and the other esters are preferably an alkanediol monoalkane. The ether acetates, the other ethers described above, and the other esters described above are more preferred. These solvents may be used singly or in combination of two or more kinds.

The content of the component (S) is not particularly limited, and the concentration which can be applied to a substrate or the like is appropriately set depending on the thickness of the coating. The viscosity of the photosensitive resin composition is preferably 5 to 500 cp, more preferably 10 to 50 cp, and most preferably 20 to 30 cp. Further, the solid content concentration is preferably from 5 to 100% by mass, more preferably from 20 to 50% by mass.

<Other ingredients>

The photosensitive resin composition of the present invention may contain an additive such as a surfactant, an adhesion improving agent, a thermal polymerization inhibiting agent, or an antifoaming agent as needed. Any one of the additives can be used by a person skilled in the art. The surfactant is a compound such as an anion, a cation or a nonionic system, a adhesion improving agent such as a conventional decane coupling agent, a thermal polymerization inhibiting agent such as hydroquinone or hydroquinone monoethyl ether, and an antifoaming agent such as an anthraquinone or a fluorine-based agent. Compounds, etc.

<Modulation Method of Photosensitive Resin Composition>

In the photosensitive resin composition of the present invention, the above-mentioned respective components may be mixed (dispersed, kneaded) by a three-roll mill, a ball mill, a sand mill or the like, and a filter such as a membrane filter of 5 μm is required. Filter and modulate.

<<LCD panel>>

The liquid crystal panel of the present invention has a spacer formed of a photosensitive resin composition. The point other than the spacer is the same as that of a general liquid crystal panel, and only the method of forming the spacer will be described below.

First, on a substrate on which a spacer is formed, a contact copy type coating device or a rotator (rotary coating device) using a roll coater, a reversible coater, a bar coater, or the like, a curtain flow coating In the non-contact type coating apparatus such as a cloth, the photosensitive resin composition of the present invention is applied and dried, and a solvent is removed to form a photosensitive resin layer.

Next, the photosensitive resin layer is irradiated with an active energy ray such as ultraviolet rays or excimer laser light through a negative mask to perform partial exposure processing. When exposed, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a xenon lamp, a carbon arc lamp, or the like can be used to emit ultraviolet light. The amount of exposure may vary depending on the composition of the photosensitive resin composition, and is preferably, for example, about 50 to 600 mJ/cm ² .

Then, the photosensitive resin layer after the exposure is developed with a developing solution to form a spacer. The developing method is not particularly limited, and a dipping method, a spraying method, or the like can be used. Specific examples of the developer include an organic system such as monoethanolamine, diethanolamine or triethanolamine, or an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, aqueous ammonia or a quaternary ammonium salt. Since the photosensitive resin composition of the present invention has moderate developability, development can be appropriately performed.

Next, a post-baking treatment is performed on the spacer after development to heat-harden. The temperature of the post-baking treatment is preferably 150 to 250 °C.

The spacer formed using the photosensitive resin composition of the present invention has high breaking strength and good shape or adhesion to the substrate. Further, since the specific dielectric constant is low, it is effective when a spacer is formed on the array substrate.

In the following, the invention is illustrated in more detail by the examples, but the invention is not limited by the examples.

[Examples] <Examples 1 to 5 and Comparative Examples 1 to 3>

Each component shown in the following Table 1 was mixed and dissolved in a solvent to prepare a photosensitive resin composition.

In Table 1, each abbreviation is as follows, and the numerical value in the scratch is the compounding amount (parts by mass).

(A)-1: glycidyl methacrylate: methacrylic acid: 3,4-epoxycyclohexylmethyl methacrylate = 60:20:20 (mass ratio) resin (mass average molecular weight 13000)

(A)-2: glycidyl methacrylate: methacrylic acid: 2,3-epoxycyclopentyl methyl methacrylate = 60:20:20 (mass ratio) of resin (mass average molecular weight 15000) )

(A)-3: Glycidyl methacrylate: methacrylic acid: tricyclodecyl methacrylate = 72:18:10 (mass ratio) of resin (mass average molecular weight 14000)

(A)-4: Glycidyl methacrylate: methacrylic acid = 80:20 (mass ratio) resin (mass average molecular weight 15000)

(A)-5: Glycidyl methacrylate: methacrylic acid: isobutyl methacrylate = 72:18:10 (mass ratio) resin (mass average molecular weight 15000)

(A)-6: Glycidyl methacrylate: methacrylic acid: tricyclodecyl methacrylate = 71:20:9 (mass ratio) of resin (mass average molecular weight 12,800)

(A)-7: glycidyl methacrylate: methacrylic acid: 3,4-epoxycyclohexylmethyl methacrylate: tricyclodecyl methacrylate = 35.5:20:35.5:9 (mass Resin (mass average molecular weight 11000)

(B)-1: Dipentaerythritol hexaacrylate (DPHA)

(C)-1: 2-methyl-1-(4-methylthiophenyl)-2-morpholinylpropan-1-one ("IRGACURE 907", manufactured by Chiba Specialty Chemical Co., Ltd.)

(C)-2: 2-Benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1 ("IRGACURE 369", manufactured by Chiba Specialty Chemical Co., Ltd.)

(C)-3: Ethylketone, 1-[9-ethyl-6-(2-methylbenzylidenyl)-9H-indazol-3-yl], 1-(o-ethylindenyl) ("IRGACURE OXE02" by Chiba Specialty Chemical Co., Ltd.)

(S)-1: a mixed solvent of PGMEA/diethylene glycol methyl ether/3-methoxypropionate methyl ester=22/22/56 (mass ratio)

(S)-2: PGMEA/diethylene glycol methyl ether = 50/50 (mass ratio) mixed solvent

<evaluation> [developability evaluation]

The photosensitive resin composition prepared in each of the above Examples and Comparative Examples was applied onto a 6-inch glass substrate (manufactured by Dow Corning Co., Ltd., 1737 glass), and then dried at 100 ° C for 2 minutes to obtain a film. A photosensitive resin layer having a thickness of 3.8 μm. Next, on the photosensitive resin layer, ultraviolet light was selectively irradiated through a negative mask, and a 0.5% aqueous solution of tetramethylammonium hydroxide was used as a developing solution, and a dot pattern was formed by stirring and developing at 23 °C. Next, the developability was evaluated by measuring the time (BP: breakpoint) at which the unexposed portion was completely dissolved. The results are shown in Table 2.

[Adhesion evaluation]

A dot pattern is formed in the same manner as the "developability evaluation" described above. The development time is BP × 1.5 based on the aforementioned break point (BP). Then, it was washed with pure water, and the formed pattern was subjected to post-baking treatment at 100 ° C for 10 minutes, and then post-baking treatment at 220 ° C for 40 minutes to form a dot pattern.

Then, the optimum dot exposure (EOP) necessary for reproducing the mask size and the exposure amount of 50 mJ/cm ² were examined, and the dot pattern size which can be developed was examined, and the adhesion was evaluated. The results are shown in Table 2. Further, "None" in Table 2 means a case where the pattern is peeled off even if it is 20 μm after development, and the pattern is peeled off.

[Shape evaluation]

The exposure amount was the above EOP, and a dot pattern having a diameter of 15 μm was formed in the same manner as the above-mentioned "adhesion evaluation". Then, the shape of the pattern was observed by SEM, and the following criteria were evaluated. The results are shown in Table 2.

○: The surface has no rough and good shape.

△: The surface has a rough condition.

×: The surface and the side surface have large irregularities. The dissolution residue can be seen.

[Specific dielectric constant evaluation]

The exposure amount was the above EOP, and a dot pattern having a diameter of 15 μm was formed in the same manner as the above-mentioned "adhesion evaluation". Then, using a dielectric constant measuring device SSM495 (manufactured by Nippon SSM Co., Ltd.), the dielectric constant of the film thickness direction of the dot pattern to the vacuum was measured. The results are shown in Table 2.

As is clear from Table 2, a constituent unit derived from an unsaturated compound containing an epoxy group having no alicyclic group, and an unsaturated compound containing an alicyclic epoxy group or an unsaturated compound containing an alicyclic group are used. Each of the examples of the resin of the constituent unit derived has a moderate developability with a break point of 15 to 30 seconds. Further, the dot pattern of 9 to 15 μm can be developed by an exposure amount of 50 mJ/cm ² , and the adhesion is excellent, and the pattern shape is also good. Further, in Examples 1 to 3, the specific dielectric constant was lower than Comparative Examples 1 and 2. Further, the specific dielectric constants of Examples 4 and 5 were lower than the equivalent values of Comparative Example 3.

On the other hand, in each of the comparative examples using the resin having no alicyclic group, the breakage point was less than 10 seconds, and the development resistance was deteriorated. Further, the pattern cannot be formed with an exposure amount of 50 mJ/cm ² and the adhesion is low. Further, when exposed by EOP, the pattern shape was not good, and the case where the shape was poor due to the elution residue in Comparative Example 3 was confirmed.

Claims (5)

A photosensitive resin composition containing a photosensitive resin composition of an alkali-soluble resin (A), a photopolymerizable monomer (B), and a photopolymerization initiator (C), characterized in that the alkali-soluble resin (A) It is a constituent unit (a1) derived from an unsaturated carboxylic acid, a constituent unit (a2) derived from an unsaturated compound having an epoxy group having no alicyclic group, and an alicyclic epoxy group. The constituent unit (a3) derived from the unsaturated compound, and the total ratio of the ratio of the constituent unit (a2) to the constituent unit (a3) is 71% by mass or more, and the ratio of the constituent unit (a3) is 20%. 60% by mass. A photosensitive resin composition containing a photosensitive resin composition of an alkali-soluble resin (A), a photopolymerizable monomer (B), and a photopolymerization initiator (C), characterized in that the alkali-soluble resin (A) It is a constituent unit (a1) derived from an unsaturated carboxylic acid, a constituent unit (a2) derived from an unsaturated compound containing an epoxy group having no alicyclic group, and an unsaturated group containing an alicyclic group. The constituent unit (a4) derived from the compound, and the ratio of the above-mentioned constituent unit (a2) is 71% by mass or more. The photosensitive resin composition of claim 2, wherein the ratio of the constituent unit (a4) is 1 to 25% by mass. The photosensitive resin composition according to any one of claims 1 to 3, which is used for forming a spacer for a liquid crystal panel. A liquid crystal panel characterized by having a patent application scope A spacer formed of the photosensitive resin composition according to any one of items 1 to 4.