KR20070091974A - Photoresist composition for color filter - Google Patents

Abstract

A photosensitive resin composition for a color filter is provided to is used for manufacturing a column spacer or a protective film of a photoresist which maintains uniform cell gap in coupling a color filter substrate and TFT(Thin Film Transistor) substrate, and to manufacture a pattern showing excellent developability, coatability, resolution, pattern stability, residual film rate and uniformity. A photoresist resin composition for a color filter comprises (a) an alkali-soluble copolymer containing an acrylic resin; (b) a polyfunctional acrylic monomer having one or more of ethylenically unsaturated bonds; (c) a bifunctional acrylic monomer derived from barbituric acid, which is represented by the formula(1) or (2), alone or a mixture thereof; (d) a photopolymerization initiator; and (e) a solvent. In the formulae(1) and (2), R is a hydrogen atom or an alkyl group having 1-6 carbon atoms, X is an alkylene group having 2-6 carbon atoms, and n is an integer of 1-6.

Description

Photosensitive resin composition for color filters {Photoresist composition for color filter}

The present invention relates to a photosensitive resin composition for a protective film or a column spacer used in a color filter which is a liquid crystal display device, and more particularly, to a pattern thickness having a desired thickness when forming a column spacer of a liquid crystal display device, as well as developability and coating property. The present invention relates to a photosensitive resin composition having excellent resolution, pattern stability, residual film ratio, flatness, and the like.

The liquid crystal display device is constituted by upper and lower panels having a constant interval and liquid crystal injected between the panels. The gap between the upper panel and the lower panel is called a cell gap and determines the thickness of the injected liquid crystal. In the liquid crystal display device, the cell gap must be kept constant throughout the panel. This is because the uniformity of the cell gap affects the fast response characteristics, contrast, and wide viewing angle of the liquid crystal.

Conventionally, a technique for adjusting the cell gap is to control the cell gap by dispersing and applying spherical or cylindrical spacer particles such as transparent glass, silica particles, or plastic beads that are slightly larger than the cell gap in the middle of two substrates. Has been used.

However, this method not only makes it difficult to disperse and apply the spacer particles in a desired position, but also causes other problems in that the particle position changes due to the agglomeration, vibration, or external impact of the particles.

According to this method, a process of causing color change and image distortion of the liquid crystal display device due to spacer particles or scattering incident light in the effective pixel region of the liquid crystal display device, and causing damage to the alignment layer and the electrode, etc. It may also provide the cause of the failure.

In order to solve this problem, a method of manufacturing a patterned column spacer using a photosensitive resin composition has been proposed. This method is performed by applying a photosensitive resin composition to a substrate and then exposing the substrate coated with the photosensitive resin composition to ultraviolet rays using a mask having a predetermined pattern corresponding to the column spacer pattern, and removing the unexposed portion of the resin composition. Form a spacer. Since this method can form the spacer in a fixed position at a desired position, the above-mentioned problem can be solved and the contrast and aperture ratio of the liquid crystal display element can be improved.

Examples of such methods include Korean Patent Laid-Open Publication Nos. 1999-88297, 2002-76924, and 2002-66504. These published patents propose a composition for column spacers comprising a polyvalent acrylate crosslinking agent and a photoinitiator using a binder polymer as an acrylic copolymer, and it is possible to form column spacers having excellent pattern stability, film thickness uniformity, and thermal stability. It is described. However, in order to manufacture a column spacer having a desired thickness in such a patterned column spacer, the photosensitive resin film coating process must be repeatedly performed several times, and the thickness of the final spacer film is uneven due to the volume shrinkage occurring in the drying process after curing. Is inevitable.

The thickness variation occurring in the final spacer causes the cell gap to be uneven in the bonding process of the upper substrate and the lower substrate.

If there is a deviation in the thickness of the spacers formed on the color filter substrate, the gap formed by the bonding with the array substrate shows a difference at each point of the substrate, and as a result, the characteristics of the liquid crystal display are deteriorated by uneven cell gap after the bonding. Phenomenon occurs. In this regard, the above-mentioned prior art techniques have focused on reducing the thickness variation between the formed spacers. However, to date, this approach has not been an effective countermeasure to cure cell gap non-uniformity.

The above-described methods of Korean Patent Laid-Open Publication Nos. 1999-88297, 2002-76924, and 2002-66504 describe that the advantages of formation of patterns, pattern stability, and film thickness thermal stability are good. However, the patterns formed in this way do not describe the mechanical properties such as inherent elastic properties and compression displacement of the upper and lower panels of the liquid crystal display in actual processes. It is a very important property in terms of fairness.

In fact, when the uniformity and compression of the physical properties of the column spacers are insufficient, they are destroyed in the lower overcoat, black matrix, color filter pixels, etc. due to the pressure applied to the panels from the outside during the panel forming process or the final panel completion. Defects may occur.

Therefore, it is essential to consider the flatness and compression characteristics simultaneously as the column spacer as well as the protective film for the color filter.

Another object of the present invention is to improve the mechanical properties, especially compression displacement and elastic recovery rate of the pattern formed when the photosensitive resin composition comprising the same by providing an elastic force to the photosensitive polymer used.

It is also an object to provide a photosensitive resin composition that can maintain the pattern stability during development, excellent adhesion, excellent pattern flatness and high film strength.

Another object of the present invention is to provide a photosensitive resin composition capable of maintaining a constant cell gap by reducing spacer thickness variation and acting as a buffer against external impact by paying attention to the mechanical properties of the spacer to be finally formed.

In order to achieve the above technical problem, the present invention provides a photosensitive resin composition composed of the following composition.

(a) an alkali-soluble copolymer comprising an acrylic resin;

(b) polyfunctional acrylic monomers having at least one ethylenically unsaturated bond;

(c) bifunctional acrylic monomers alone or mixtures thereof derived from barbituric acid represented by the following general formula (1) or (2);

(d) photopolymerization initiators; And

(e) solvent.

In the above formula, R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, X represents an alkylene group having 2 to 6 carbon atoms, and n is an integer of 1 to 6.

Wherein R is as defined in formula (1).

The present invention will be described in more detail as follows.

(a) Alkali-soluble copolymer containing acrylic resin

In the present invention, the (a) alkali-soluble copolymer,

(a1) unsaturated carboxylic acids, unsaturated carboxylic anhydrides or a mixture of both materials; And

(a2) an olefin compound containing an alcohol group of a side branch;

(a3) After radical polymerization of at least one compound selected from olefinically unsaturated compounds to obtain a polymerized product, an isocyanate compound capable of reacting with an alcohol group of the olefin compound including an alcohol group of (a2) side branch is selected and added. It may be a polymer obtained by the reaction.

As the compound (a1), acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, metaconic acid and anhydrides of these dicarboxylic acids may be used. In particular, acrylic acid, methacrylic acid and maleic anhydride are preferred in view of copolymerization reactivity, heat resistance and easy availability. These compounds may be used in combination of one or more kinds.

As the compound (a2), carboxylic acid esters including hydroxyalkyl esters such as 2-hydroxy ethyl methacrylate or 2-hydroxy propyl methacrylate can be used.

Examples of the compound (a3) include acrylic acid glycidyl ester, methacrylic acid glycidyl ester, α-ethyl acrylic acid glycidyl ester, n-propyl acrylic acid glycidyl ester, n-butyl acrylic acid glycidyl ester, and acrylic acid. -3,4-epoxy butyl ester, methacrylic acid-3,4-epoxy butyl ester, acrylic acid-6,7-epoxy heptyl ester, methacrylic acid-6,7-epoxy heptyl ester, α-ethyl acrylic acid-6, Epoxy group-containing unsaturated compounds such as 7-epoxy heptyl ester, o-vinyl benzyl glycidyl ether, m-vinyl benzyl glycidyl ether, p-vinyl benzyl glycidyl ether, such as methyl methacrylate, ethyl methacrylate, methacrylic acid alkyl esters such as n-butyl methacrylate, sec-butyl methacrylate and t-butyl methacrylate; Acrylic acid alkyl esters such as methyl acrylate and isopropyl acrylate; Methacrylic acid cycloalkyl esters such as cyclohexyl methacrylate, 2-methyl cyclohexyl methacrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate and isobornyl methacrylate; Acrylic acid cycloalkyl esters such as cyclohexyl acrylate, 2-methyl cyclohexyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, isoboroyl acrylate and trimethylcyclohexyl methacrylate; Methacrylic acid aryl esters such as petyl methacrylate and benzyl methacrylate; Acrylic acid aryl esters such as phenyl acrylate and benzyl acrylate; Dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate and diethyl itaconic acid; Compounds can be used. In addition, styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, vinyl toluene, p-methoxy styrene, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide Olefinically unsaturated compounds such as vinyl acetate, 1,3-butadiene, isoprene and 2,3-dimethyl-1,3-butadiene may be used. The above-mentioned olefinically unsaturated compound can be used in mixture of 2 or more types.

(a2) Examples of the isocyanate compound capable of reacting with an alcohol group of an olefin compound containing an alcohol group of a side branch include ethyl isocyanate, propyl isocyanate, butyl isocyanate, isopropyl isocyanate, phenyl isocyanate, benzyl isocyanate, cyclohexyl isocyanate, toluene diisocyanate, Methane diisocyanate, acryloyl isocyanate, methacryloyl isocyanate (hereinafter referred to as MOI) and isocyanatoethyl methacrylate (MOEI), isocyanatoethyl acrylate, 3,3,5-isopropenyl-α- Isocyanates, such as (alpha)-dimethylbenzyl isocyanate (TMI), hexyl isocyanate, and hexamethylene diisocyanate, can be used.

As a solvent used for the synthesis | combination of the said copolymer, Alcohol, such as methanol and ethanol; Ethers such as tetrahydrofuran, diethylene glycol dimethyl ether and diethylene glycol diethyl ether; Propylene glycol alkyl ether acetates, such as propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, and propylene glycol butyl ether acetate, etc. are preferable.

As the polymerization initiator that can be used for synthesizing the copolymer, an ordinary radical polymerization initiator may be used. For example, 2,2'-azobis isobutyronitrile, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobis- (4-methoxy-2,4 Azo compounds such as -dimethylvaleronitrile); Organic peroxides and hydrogen peroxide, such as benzoyl peroxide, t-butyl peroxy pibarate, 1,1'-bis- (t-butyl peroxy) cyclohexane, are mentioned. When a peroxide is used as a radical polymerization initiator, you may use it as a redox initiator by using a peroxide together with a reducing agent.

The content of the copolymer (a) in the photosensitive resin of the present invention is preferably about 10 to about 70% by weight, more preferably about 20 to 50% by weight, based on the photosensitive resin solid content. It is preferable in the storage stability, alkali solubility, heat resistance, and surface hardness of a copolymer that content of (a) alkali-soluble copolymer is the said range.

(b) a polyfunctional acrylic monomer having at least one ethylenically unsaturated bond

The photosensitive resin composition of this invention can use the polyfunctional acrylic monomer which has one or more ethylenically unsaturated bond as a photopolymerizable material. Monofunctional, bifunctional or trifunctional or higher (meth) acrylates are preferred as the polyfunctional acrylic monomers of the present invention from the viewpoint of polymerizability and the heat resistance and surface hardness of the resulting protective film.

As monofunctional (meth) acrylate, 2-hydroxy ethyl (meth) acrylate, carbitol (meth) acrylate, isobornyl (meth) acrylate, 3-methoxy butyl (meth) acrylate, 2 -(Meth) acryloyl oxy ethyl 2-hydroxy propyl phthalate can be used.

As a bifunctional (meth) acrylate, for example, ethylene glycol (meth) acrylate, 1,6-hexanediol (meth) acrylate, 1,9-nonanediol (meth) acrylate, and propylene glycol (meth) acryl Rate, tetraethylene glycol (meth) acrylate, bisphenoxy ethyl alcohol fluorene diacrylate, polyethylene glycol acrylate (ethylene glycol repeat number = 3-40), polyethylene glycol methacrylate (ethylene glycol repeat number = 3) 40), polybutylene glycol acrylate (butylene glycol repeating number = 3-40), polybutylene glycol methacrylate (butylene glycol repeating number = 3-40), etc. are mentioned.

As (meth) acrylate more than trifunctional, for example, tris hydroxyethyl isocyanurate tri (meth) acrylate, trimethyl propane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth) ) Acrylate, dipentaerythritol hexa (meth) acrylate, can be used.

These monofunctional, bifunctional or trifunctional or more (meth) acrylates can be used individually or in combination.

In the present invention, the content of the multifunctional acrylic monomer is preferably included in about 10 to about 50% by weight based on the total solids of the photosensitive resin.

(c) a bifunctional acrylic monomer derived from barbituric acid represented by the formula (1) or (2)

The photosensitive resin composition of the present invention includes an acrylic monomer represented by Formula 1 or Formula 2 alone or in combination. For example, the bifunctional acrylic monomer represented by Formula 2 may be obtained by a reaction as in Scheme 1 below. have.

Wherein R is as defined in formula (1).

Specifically, barbituric acid is reacted with epihalohydrin such as epichlorohydrin or epibromohydrin under a base to obtain a precursor having two epoxy groups, which is reacted with 2 equivalents of acrylic acid to ring-open an epoxy. The bifunctional acrylic monomer represented by can be obtained.

The bifunctional acrylic monomer derived from barbituric acid thus obtained is preferably used in combination with the multifunctional monomer of (b) described above as 10 to 50% by weight in the photosensitive resin composition. It is preferable that the content is in the above range in the improvement of the compression recovery rate, the heat resistance and the adhesion.

(d) photopolymerization initiator

The photosensitive resin composition of this invention initiates photopolymerization of the (a) alkali-soluble copolymer which has a side chain double bond by exposure, (b) polyfunctional acrylic monomer, and (c) bifunctional acrylic monomer derived from barbituric acid. And a photopolymerization initiator for generating active species. In addition, the photopolymerization initiator may be included in about 0.5 to 15% by weight of the total composition of the photosensitive resin composition. If the content is less than 0.5% by weight, the coating film is likely to be lost in the developing process, and even if the coating film is maintained in the developing step, it is difficult to obtain a coating film having a sufficiently high crosslink density. When the content of the photoinitiator exceeds 15% by weight, not only the heat resistance and planarization characteristics of the protective film are lowered, but also the light transmittance as the protective film tends to be lowered.

As a photoinitiator, Irgacure 907, Irgacure 369, Irgacure ox01, Irgacure 242, thioxanthone, 2, 4- diethyl thioxanthone, thioxanthone-4-sulfonic acid, benzophenone, 4,4'-bis (diethyl Amino) benzophenone, acetophenone, p-dimethylaminoacetophenone, α, α'-dimethoxyacetoxy benzophenone, 2,2'-dimethoxy-2-pentylacetophenone, p-methoxyacetophenone, 2- Methyl [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-diethylamino-1- (4-morpholinophenyl) -butan-1-one, 2 -Hydroxy-2-methyl-1-phenylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone, etc. Ketones; Quinones such as anthraquinone and 1,4-naphthoquinone; 1,3,5-tris (trichloromethyl) -s-triazine, 1,3-bis (trichloromethyl) -5- (2-chlorophenyl) -s-triazine, 1,3-bis (trichloro Halogen compounds such as rophenyl) -s-triazine, phenacyl chloride, tribromomethylphenyl sulfone and tris (trichloromethyl) -s-triazine; Peroxides such as di-t-butyl peroxide; Acyl phosphine oxides, such as 2,4,6-trimethyl benzoyl diphenyl phosphine oxide, can be used. In the present invention, the photopolymerization initiator may be used alone or in combination.

(e) solvent

In the present invention, the following materials may be used as a solvent for preparing the copolymer or maintaining the solid content and the viscosity of the composition. Alcohols such as methanol and ethanol; Ethers such as tetrahydrofuran, diethylene glycol dimethyl ether and diethylene glycol diethyl ether; Propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate and propylene glycol butyl ether acetate. Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol methyl ether acetate in view of solubility in the solvent, reactivity with each component, and convenience of coating film formation; Ketones such as methyl ethyl ketone, cyclohexanone and 4-hydroxy-4-methyl-2-pentanane; Methyl, ethyl, propyl, butyl ester of acetic acid, ethyl of 2-hydroxypropionic acid, methyl ester, ethyl ester of 2-hydroxy-2-methylpropionic acid, methyl, ethyl, butyl ester of hydroxyacetic acid, ethyl lactate, lactic acid Ethyl, propyl lactate, butyl lactate, methyl of methoxyacetic acid, ethyl, propyl, butyl ester, methyl of ethyl propoxy, ethyl, propyl, butyl ester, methyl of methyl butoxy, ethyl, propyl, butyl ester, 2-methic Methyl, ethyl, propyl, butyl ester of oxypropionic acid, methyl, ethyl, propyl, butyl ester, methyl of ethoxypropionic acid, methyl, ethyl, propyl, butyl ester of 2-butoxypropionic acid, methyl of 3-methoxypropane, Ester, such as ethyl, propyl, butyl ester, methyl of 3-ethoxy propionic acid, ethyl, propyl, butyl ester, and methyl, ethyl, propyl, butyl ester of 3-butoxy propionic acid Use of leu is preferred.

The solvent may also be used with high boiling solvents. As the high boiling point solvent which can be used, for example, N-methyl formamide, N, N-dimethyl formamide, N-methyl acetamide, N, N-dimethyl acetamide, N-methyl pyrrolidone, dimethyl sulfoxide, benzyl ethyl ether Can be mentioned.

In the photosensitive resin composition of the present invention, the content of the solvent may be included in an appropriate amount depending on the intended use. Generally, the solvent accounts for about 50 to about 80% by weight of the total composition of the photosensitive resin composition.

On the other hand, the photosensitive resin composition of the present invention may include additives commonly used in the photosensitive resin composition in order to improve a specific function, such as a surfactant, a polymerization inhibitor or an adhesion aid, in addition to the above-mentioned composition (a) to (e). .

For example, the photosensitive resin composition of this invention is brand name FC-129, FC-170C, FC-430, F-172, F-173, F-183, F-470, F-475, Shin-Etsu Silicone company of 3M company Fluorine and silicone based surfactants such as KP322, KP323, KP340, KP341. The amount of the surfactant added is preferably 5 parts by weight or less, more preferably 2 parts by weight or less based on 100 parts by weight of the alkali-soluble copolymer. When the amount of the surfactant added exceeds 5 parts by weight with respect to the copolymer, problems such as foaming occur during application.

Moreover, the photosensitive resin composition of this invention may also contain an adhesion | attachment adjuvant in order to improve adhesiveness with a base | substrate. A functional silane coupling agent may be used as the adhesion aid, for example trimethoxysilyl benzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatepropyltri Ethoxysilane, (gamma)-glycidoxy propyl trimethoxysilane. It is preferable that the addition amount of the said adhesion | attachment adjuvant is 20 weight part or less with respect to 100 weight part of (a) alkali-soluble copolymers, More preferably, it is 10 weight part or less. When content of the said adhesion | attachment adjuvant exceeds 20 weight part with respect to the said copolymer, the heat resistance fall of a coating film will be easy to be caused.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples.

Alkali-soluble copolymer used in the embodiment of the present invention is prepared by using the monomer described above is just one example. First, 5 parts by weight of 2,2'-azobis isobutyronitrile, 35 parts by weight of styrene, 15 parts by weight of methacrylic acid, 40 parts by weight of glycidyl methacrylate, 10 parts by weight of 2-hydroxyethyl methacrylate In addition, 200 parts by weight of propylene glycol monomethyl ether acetate was added to the reactor and replaced with nitrogen, followed by gentle stirring. The temperature of the solution was increased to 70 ° C. and maintained for 4 hours. Solid content concentration in this polymer solution was 35 weight%.

Example 1

100 parts by weight of the solid of the copolymer (binder), 40 parts by weight of dipentaerythritol penta / hexa acrylate as a polyfunctional acrylic monomer, R in the general formula (1) is a methyl group, and X is an ethylene group 40 parts by weight of a bifunctional monomer (G1), 5 parts by weight of Irgacure 907 as a photopolymerization initiator, and 5 parts by weight of ethyl 4-diethylaminobenzoate were sequentially added to propylene glycol monomethyl ether acetate so that the total solid content was 35% by weight. Stir at room temperature. Subsequently, this solution was filtered with the filter of 0.45 micrometers of pore diameters, and the photosensitive resin composition was produced.

The photosensitive resin composition was applied to a color filter glass substrate using a spin coater, and heated at a temperature of 100 ° C. for 2 minutes on a hot plate to remove the solvent to some extent to form a coating film. Subsequently, the coating film was irradiated with ultraviolet light having a central wavelength of 365 nm through a photo mask at a light amount of 150 mJ / cm 2 and then developed with an aqueous alkali solution. The developed coating film was baked at 220 ° C. for 30 minutes in a clean oven to form a dot spacer pattern having a thickness of 3 μm and a width of 20 μm.

The spacer pattern thus formed was measured for pattern shape, flatness, heat resistance, recovery rate, and adhesion by the following method.

a. Pattern shape

The spacer pattern was cut in the vertical direction, and the cut surface was observed with an electron microscope, and it was evaluated that the length ratio of the bottom and the top was 85% or more and good, and 85% or less.

b. Flatness (%)

Surface irregularities of the pattern were examined at 25 different points on the substrate in α-step to calculate the rate of change of thickness from the difference between the maximum and minimum thicknesses.

c. Heat resistance

The spacer pattern was heated in a clean oven at 240 ° C. for 60 minutes to measure changes in film thickness before and after heating. If the change in film thickness was less than 10%, the heat resistance was good, and if it was 10% or more, the heat resistance was evaluated as poor.

d. Adhesion

After maintaining for 2 hours at 120 ℃, 100% humidity was expressed as the number of eyes remaining of 100 eyes by the ASTM D3359 method.

e. Compression displacement and recovery

The recovery rate was calculated by measuring the compression displacement (D1 / D2) of the spacer pattern with an ultra-microscopic compressive hardness tester manufactured by Shimazu. Compression displacement and recovery were measured by load-unload using a planar indenter with a diameter of 50 μm. In the test, the reference value applied to the indenter was 5 gf / cm 2, the loading speed was 0.45 gf / sec, and the holding time was 2 seconds.

Table 1 shows the test result of each test item of this example.

Example 2

It was prepared in the same manner as in Example 1 except for using a bifunctional acrylic monomer (G2) in which R is a methyl group in the formula (2) instead of G1 as an acrylic monomer derived from barbituric acid. The physical properties of each item were measured in the same manner as in Example 1 using the formed spacer pattern. Table 1 shows the test result of each test item of this example.

Example 3

An acrylic monomer derived from barbituric acid was prepared in the same manner as in Example 1 except that 20 parts by weight of G1 and 20 parts by weight of G2 were mixed. The physical properties of each item were measured in the same manner as in Example 1 using the formed spacer pattern. Table 1 shows the test result of each test item of this example.

Example 4

It was prepared in the same manner as in Example 1 except that X is a propylene group, n is 3, and R is a methyl group, instead of G1, as an acrylic monomer derived from barbituric acid. The physical properties of each item were measured in the same manner as in Example 1 using the formed spacer pattern. Table 1 shows the test result of each test item of this example.

Example 5

An acrylic monomer derived from barbituric acid was prepared in the same manner as in Example 2, except that R was a butyl group instead of G2. The physical properties of each item were measured in the same manner as in Example 1 using the formed spacer pattern. Table 1 shows the test result of each test item of this example.

Comparative Example 1

It was prepared in the same manner as in Example 1 except that no acrylic monomer derived from barbituric acid was added. The physical properties of each item were measured in the same manner as in Example 1 using the formed spacer pattern. Table 1 shows the test result of each test item of this example.

Comparative Example 2

It was prepared in the same manner as in Example 1 except that tris (2-hydroxyethyl isocyanurate triacrylate) represented by the following Formula 3 was used instead of the acryl-based monomer derived from barbituric acid. The physical properties of each item were measured in the same manner as in Example 1 using the formed spacer pattern. Table 1 shows the test result of each test item of this comparative example.

Comparative Example 3

It was prepared in the same manner as in Example 1 except for using a compound represented by the following formula (4, wherein R ₁ is a methyl group) instead of an acryl-based monomer derived from barbituric acid. The physical properties of each item were measured in the same manner as in Example 1 using the formed spacer pattern. Table 1 shows the test result of each test item of this comparative example.

Pattern shape flatness(%) Heat resistance (%) Adhesion % Recovery Example 1 Good 91 Good 100 65% Example 2 Good 92 Good 100 69% Example 3 Good 93 Good 100 74% Example 4 Good 97 Good 100 78% Example 5 Good 95 Good 100 75% Comparative Example 1 Good 86 Bad 100 61% Comparative Example 2 Good 88 Good 100 65% Comparative Example 3 Good 89 Good 100 63%

From the results in Table 1, when the acrylic monomers derived from barbituric acid are not contained at all (Comparative Example 1), it is found that not only the results are significantly lowered in the flatness and the recovery rate but also poor in the heat resistance. On the other hand, Comparative Examples 2 and 3 including trifunctional acrylic monomers structurally similar to the bifunctional acrylic monomers derived from barbituric acid represented by the general formula (1) or (2) of the present invention have good heat resistance, but are poor in flatness and recovery rate. It can be seen that.

As described above, the photosensitive resin composition of the present invention is not only a protective film by exposure after coating of the substrate, but also easily forms a pattern by an exposure / development process. By introducing the derived bifunctional acrylic monomer, the compression recovery rate, flatness, adhesion, and heat resistance are improved as compared with the conventional column spacer. Therefore, the cell gap may be kept constant due to the improved characteristics of the column spacer when the color filter substrate to which the column spacer is applied is bonded.

Claims (2)

(a) an alkali-soluble copolymer comprising an acrylic resin; (b) polyfunctional acrylic monomers having at least one ethylenically unsaturated bond; (c) bifunctional acrylic monomers alone or mixtures thereof derived from barbituric acid represented by the following general formula (1) or (2); (d) photopolymerization initiators; And (e) Photosensitive resin composition for color filters containing a solvent. Formula 1

In the above formula, R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, X represents an alkylene group having 2 to 6 carbon atoms, and n is an integer of 1 to 6. Formula 2

Wherein R is as defined in formula (1). According to claim 1, Bifunctional acrylic monomers derived from barbituric acid (barbituric acid) represented by Formula 1 or Formula 2 alone or a mixture thereof are contained in 10 to 50% by weight of the total resin composition, characterized in that Photosensitive resin composition for color filters.