TWI427418B - A positive-type photosensitive resin composition, and a liquid crystal alignment control protrusion formed - Google Patents

Description

Positive photosensitive resin composition and liquid crystal alignment control protrusion formed thereby

The present invention relates to a positive photosensitive resin composition for a liquid crystal display element. In particular, a positive photosensitive resin composition for a projection for liquid crystal alignment control which is excellent in sensitivity and has no image sticking phenomenon is provided.

The liquid crystal display element is the most widely used user in today's flat panel displays. In recent years, with the popularization of office equipment such as personal computers and word processors, LCD TVs, etc., the display of liquid crystal displays (TFT-LCDs) for thin film transistors. In terms of quality, its performance requirements are becoming more stringent.

Among the TFT-LCDs, the TN (Twisted Nematic) type LCD is currently used at the most. This TN-type LCD has been improved in technology in recent years, and the contrast of the front side, the color reproducibility, etc. are comparable to or above the CRT. However, the TN type LCD has a problem that the viewing angle is too narrow.

In order to solve this problem, the industry has developed an MVA (Multi-domain Vertically Alignmented) type LCD (vertical alignment type liquid crystal display). In the MVA type LCD, in order to make the liquid crystal in the pixel region to be a region of the plurality of alignment directions, a slit may be provided on the electrode on the light incident side in the one pixel region, and on the electrode substrate on the display side. In the same pixel region, a projection having a slope (for example, a triangular pyramid shape or a semi-convex lens shape) is formed at a position shifted from the electrode slit.

Since the protrusions are formed to control the alignment of the liquid crystal, they are referred to as protrusions for liquid crystal alignment control. The protrusion for liquid crystal alignment is tilted by providing an alignment state of liquid crystal molecules locally along the surface thereof, and even when viewed obliquely with respect to the LCD surface, the same display state as that of the front view can be obtained, and the expanded viewing angle can be obtained. purpose.

As disclosed in Japanese Laid-Open Patent Publication No. 2002-122858, a phenol novolac resin is used as a technique for forming protrusions for liquid crystal alignment control. However, such a liquid crystal alignment control protrusion has a problem that the image sticking phenomenon easily occurs when the LCD is displayed for a long time.

An object of the present invention is to provide a positive photosensitive resin composition for a liquid crystal display device. In particular, a positive photosensitive resin composition for a projection for liquid crystal alignment control which is excellent in sensitivity and has no image sticking phenomenon is provided.

The composition comprises a novolac resin (A), an esterified sensitizer (B) of o-naphthoquinonediazidesulfonic acid, and a solvent (C); wherein the novolak resin (A) is analyzed by gel permeation chromatography When the measured molecular weight is less than 150,000, and the total integrated area of the resin signal having a molecular weight of 200 to 150,000 is regarded as 100% by weight, the molecular weight thereof is between 200 and 400, and the molecular weight is between 10,000 and 10,000. 30,000% or more; and the novolak resin (A) was analyzed by a thermogravimetric analyzer, and its thermal weight loss was 10% by weight or less under conditions of 230 ° C for 30 minutes.

The following is a detailed description of each component of the invention:

Novolak resin (A)

The novolak resin (A) of the present invention is generally obtained by a condensation reaction of an aromatic hydroxy compound and an aldehyde in the presence of an acidic catalyst. Specific examples of the aromatic hydroxy compound include phenol, m-cresol, p-cresol, o-cresol, 2,3-dimethyl Phenol (2,3-xylenol), 2,5-xylenol (2,5-xylenol), 3,5-xylenol (3,5-xylenol), 3,4-xylenol (3,4 -xylenol) xylenol; m-ethyl phenol, p-ethyl phenol, o-ethyl phenol, 2, 3,5-trimethyl phenol, 2,3,5-triethyl phenol, 4-tert-butylphenol (4- Tert-butyl phenol), 3-tert-butyl phenol, 2-tert-butyl phenol, 2-tert-butyl-4-methylphenol (2-tert-butyl-4-methylphenol), 2-tert-butyl-5-methylphenol, 6-tert-butyl-3-methylphenol (6 -alkyl phenol, such as -tert-butyl-3-methylphenol; p-methoxy phenol, m-methoxy phenol, p-ethoxy P-ethoxy phenol, m-ethoxy phenol, p-propyl Alkoxy phenol such as p-propoxy phenol or m-propoxy phenol; o-isopropenyl phenol, para-iso P-isopropenyl phenol, 2-methyl-4-isopropenyl phenol, 2-ethyl-4-isopropenylphenol (2-ethyl-4- Isopropenyl phenol (isopropenyl phenol); phenyl phenol aryl phenol; 4,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl Polyhydroxyphenol such as bisphenol A, resorcinol, hydroquinone, pyrogallorl or the like. These compounds may be used singly or in combination of two or more. And the above aromatic hydroxy compound is o-cresol, m-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, etc. It is better.

Specific examples of the aldehydes condensed with the aromatic hydroxy compound of the present invention include: formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, and butyl. Butyl aldehyde, trimethyl acetaldehyde, acrolein, crotonaldehyde, cyclohexanealdehyde, furfural, furyl acrolein, benzene Benzaldehyde, terephthalaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-Hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde , cinnamaldehyde and the like. The aldehydes exemplified above may be used singly or in combination of plural kinds, with formaldehyde being preferred.

Specific examples of the acidic catalyst of the present invention include hydrochloric acid, sulfuric acid, formic acid, acetic acid, oxalic acid, p-toluenesulfonic acid and the like.

The novolac resin (A) obtained by the condensation reaction can be dissolved in a good solvent, and then re-injected into a poor solvent to precipitate, and the above steps are repeated for treatment.

The novolak resin novolak resin (A) of the present invention has a molecular weight of less than 150,000 as measured by gel permeation chromatography and a total integrated area of a resin signal having a molecular weight of 200 to 150,000 as 100% by weight. The molecular weight of 200 to 400 is 6% by weight or less, preferably 5 to 0.05% by weight, more preferably 4 to 0.05% by weight; and the molecular weight is 10,000 to 30,000, and 12% by weight or more, preferably 12 ～50% by weight, more preferably 12 to 35% by weight. In particular, when the molecular weight is from 400 to 10,000, which is from 35 to 75% by weight, and the molecular weight is from 30,000 to 150,000, which is from 1 to 10% by weight, the object and effect of the present invention are further improved.

In the present invention, when the molecular weight is in the range of 200 to 400, the content of the liquid crystal alignment control protrusion is used in a liquid crystal display, and the image sticking problem is likely to occur. When the molecular weight is between 10,000 and 30,000, the weight is less than 12% by weight. The positive photosensitive resin composition formed has a high sensitivity, is easily exposed excessively, and has a poor pattern shape.

The novolac resin (A) of the present invention is analyzed by a thermogravimetric analyzer and heated at 230 ° C for 30 minutes, and its thermal weight loss is 10% by weight or less, preferably 8 to 0.2% by weight, more preferably 6 to 0.2% by weight. %the following. When the thermal weight loss is 10% by weight or more, the formed liquid crystal alignment control protrusion is used in a liquid crystal display, and the image sticking problem easily occurs.

An ester of o-naphthoquinonediazidesulfonic acid (B) The photosensitive material of the present invention is an ester of the o-naphthoquinonediazidesulfonic acid (B), which is not particularly limited and can be optionally used. Among them, preferred are: o-naphthoquinone diazide-5-sulfonic acid, o-naphthoquinone diazide-4-sulfonic acid, o-naphthoquinone diazide-6-sulfonic acid, etc. An esterified product of azidesulfonic acid and a hydroxy compound is more preferably an esterified product of the above o-naphthoquinonediazidesulfonic acid with a polyvalent hydroxy compound. The above compounds may be completely esterified or partially esterified, and the kinds of the above hydroxy compounds are listed below.

(a) hydroxybenzophenones, for example: 2,3,4-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2, 3,4,4'-tetrahydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,3',4,4',6-pentahydroxybenzophenone, 2,2 ',3,4,4'-pentahydroxybenzophenone, 2,2',3,4,5'-pentahydroxybenzophenone, 2,3',4,5,5'-pentahydroxybenzophenone , 2,3,3',4,4',5'-hexahydroxybenzophenone and the like.

(2) General formula (I)

Wherein R ¹ to R ² are a hydrogen atom or a lower alkyl group, and R ³ to R ⁹ are a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a lower aliphatic alkenyl group. (alkenyl) and cycloalkyl, R ¹⁰ and R ¹¹ are a hydrogen atom, a halogen atom and a lower alkyl group, and x, y and z are integers of 1 to 3, and n is 0 or 1.

Specific examples of the above-mentioned hydroxyaryl compound are, for example, tris(4-hydroxyphenyl)methane, bis(4-hydroxy-3,5-dimethylphenyl)-4-hydroxyphenylmethane, bis(4-hydroxy-) 3,5-Dimethylphenyl)-3-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2, 5-dimethylphenyl)-4-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-3-hydroxyphenylmethane, bis(4-hydroxy-2,5- Dimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-3,4-dihydroxyphenylmethane, bis(4-hydroxy-2,5 -Dimethylphenyl)-3,4-dihydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-2,4-dihydroxyphenylmethane, bis(4-hydroxyl -2,5-dimethylphenyl)-2,4-dihydroxyphenylmethane, bis(4-hydroxyphenyl)-3-methoxy-4-hydroxyphenylmethane, bis(3-cyclohexyl) 4-hydroxyphenyl)-3-hydroxyphenylmethane, bis(3-cyclohexyl-4-hydroxyphenyl)-2-hydroxyphenylmethane, bis(3-cyclohexyl-4-hydroxyphenyl)- 4-hydroxyphenylmethane, bis(3-cyclohexyl-4-hydroxy-6-methylaryl)-2-hydroxyphenylmethane, bis(3-cyclohexyl-4-hydroxy-6-methylphenyl -3-hydroxybenzene Methane, bis(3-cyclohexyl-4-hydroxy-6-methylphenyl)-4-hydroxyphenylmethane, bis(3-cyclohexyl-4-hydroxy-6-methylphenyl)-3,4 -dihydroxyphenylmethane, bis(3-cyclohexyl-6-hydroxyphenyl)-3-hydroxyphenylmethane, bis(3-cyclohexyl-6-hydroxyphenyl)-4-hydroxyphenylmethane, double (3-cyclohexyl-6-hydroxyphenyl)-2-hydroxyphenylmethane, bis(3-cyclohexyl-6-hydroxy-4-methylphenyl)-2-hydroxyphenylmethane, bis(3- Cyclohexyl-6-hydroxy-4-methylphenyl)-4-hydroxyphenylmethane, bis(3-cyclohexyl-6-hydroxy-4-methylphenyl)-3,4-dihydroxyphenylmethane , 1-[1-(4-hydroxyphenyl)isopropyl]-4-[1,1-bis(4-hydroxyphenyl)ethyl]benzene, 1-[1-(3-methyl-4 -Hydroxyphenyl)isopropyl]-4-[1,1-bis(3-methyl-4-hydroxyphenyl)ethyl]benzene.

(3) General formula (II)

In the formula, R ¹² and R ¹³ are a hydrogen atom or a lower alkyl group, and x' and y' are integers of 1 to 3.

Specific examples of the (hydroxyphenyl) hydrocarbons of the above formula: 2-(2,3,4-trihydroxyphenyl)-2-(2',3',4'-trihydroxyphenyl)propane, 2- (2,4-dihydroxyphenyl)-2-(2',4'-dihydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(4'-hydroxyphenyl)propane, double (2,3,4-trihydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)methane, and the like.

(4) Other aromatic hydroxy compounds such as phenol, p-methoxyphenol, dimethyl phenol, hydroquinone, bisphenol A, naphthol, pyrocatechol, 1 , pyrogallol monomethyl ether, pyrogallol-1,3-dimethyl ether, 3,4,5 -gallic acid, partially esterified or partially etherified 3,4,5-trihydroxybenzoic acid, and the like. The above hydroxy compound is preferably 2,3,4-trihydroxybenzophenone or 2,3,4,4'-tetrahydroxyoxybenzophenone. The above hydroxy compounds may be used singly or in combination of several kinds.

The photosensitive material of the ortho-naphthoquinonediazidesulfonic acid ester (B) in the resin composition of the present invention may be a compound containing a quinonediazide group, for example, o-naphthoquinonediazide-4 (or 5) sulfonate. The acid halide salt and the hydroxy compound of the above (1) to (4) are subjected to a condensation reaction, and may be completely esterified or partially esterified. The condensation reaction is usually carried out in dioxane or N-pyrrolidone. It is preferably carried out in an organic solvent such as (N-pyrrolidone) or acetamide, and in the presence of a base condensing agent such as triethanolamine, an alkali metal carbonate or an alkali metal hydrogencarbonate.

In this case, it is preferably 50 mol% or more, more preferably 60 mol% or more and o-naphthoquinonediazide-4 (or 5) sulfonate, based on 100 mol% of the total of the hydroxyl groups in the hydroxy compound. The acid halide salt is condensed to form an esterified product, that is, the degree of esterification is 50% or more, preferably 60% or more.

The ortho-naphthoquinone diazide sulfonic acid ester ester (B) of the present invention is used in an amount of 1 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the novolak resin (A). Good is 20~40 parts by weight.

Solvent (C)

The solvent used in the present invention requires an organic solvent which is relatively easy to dissolve with other organic components.

The solvent (C) of the photosensitive resin composition of the present invention is used in an amount of 700 to 2,000 parts by weight, preferably 800 to 1,800 parts by weight, more preferably 900 to 1,600, based on 100 parts by weight of the novolak resin (A). Parts by weight.

The solvent (C) of the present invention is, for example, an ether type or an ester type. Among them, specific examples of ethers are: ethylene glycol monopropyl ether, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether, ethylene glycol ether (ethylene glycol monoethyl ether), diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether. Specific examples of the ester system are: ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate , propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, and ethyl lactate. These solvents may be used alone or in combination of two or more. Among the above solvents, propylene glycol monomethyl ether acetate and ethyl lactate are preferred.

Additive (D)

In the positive photosensitive resin composition of the present invention, an aromatic hydroxy compound may be further added to adjust the sensitivity or viscosity of the composition. Specific examples of the aromatic hydroxy compound suitable for the present invention are, for example, Japan Honshu Chemical Industry Co., Ltd. trade names TPPA-1000P, TPPA-1100-2C, TPPA-1100-3C, TPPA-1100-4C, TPPA-1200-24X, TPPA Commercial products such as -1200-26X, TPPA-1300-235T, TPPA-1600-3M6C, TPPA-MF, among which the products of the trade name TPPA-1600-3M6C and TPPA-MF are preferred, which can be used alone or in combination. . The aromatic hydroxy compound is used in an amount of usually from 0 to 20 parts by weight, preferably from 0.5 to 18 parts by weight, more preferably from 1.0 to 15 parts by weight, based on 100 parts by weight of the novolak resin (A).

The positive photosensitive resin composition of the present invention may further contain an adhesion promoter, a surface leveling agent, a diluent, and a dye having good compatibility, and among them, a auxiliaries of the present invention, for example, melamine (melamine) The compound and the decane-based compound function to increase the adhesion between the positive photosensitive resin composition and the attached substrate, and specific examples of the melamine are commercially available: Cymel-300, 303 (manufactured by Mitsui Co., Ltd.), MW-30MH, MW. -30, MS-11, MS-001, MX-750, MX-706 (Sanwa Chemical), etc. Specific examples of the silane compound are, for example, vinyltrimethoxydecane, vinyltriethoxydecane, vinyltris(2-methoxyethoxy)decane, and N-(2-aminoethyl). -3-aminopropylmethyldimethoxydecane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 3-epoxypropyl Alcohol propyl trimethoxy decane, 3-glycidyl propyl methyl dimethoxy decane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxy decane, 3-chloropropylmethyl Dimethoxydecane, 3-chloropropyltrimethoxydecane, 3-methylpropoxypropyltrimethoxydecane, 3-thiolpropyltrimethoxydecane, and the like. The amount of the adhesion aid of the melamine compound is generally from 0 to 20 parts by weight, preferably from 0.5 to 18 parts by weight, more preferably from 1.0 to 15 based on 100 parts by weight of the novolak resin (A). The amount of the adhesion aid of the silane compound is usually 0 to 2 parts by weight, preferably 0.001 to 1 part by weight, more preferably 0.005 to 0.8 part by weight.

The surface flattening agent which can be used in the present invention is, for example, a fluorine-based surfactant, a silicone-based surfactant, or the like. Specific examples of the fluorine-based surfactant include commercially available 3M Flourate FC-430, FC-431, Tochem product F top EF122A, 122B, 122C, 126, and BL20. Specific examples of the silicone surfactant are, for example, SF8427, SH29PA, and the like commercially available from Toray Dow Corning Silicon. The surfactant is used in an amount of usually from 0 to 1.2 parts by weight, preferably from 0.025 to 1.0 part by weight, more preferably from 0.050 to 0.8 part by weight, based on 100 parts by weight of the novolak resin (A).

A diluent which can be used in the present invention is a diluent such as trade name RE801, RE802 (manufactured by Imperial Ink).

The dyes which are compatible for use in the present invention are, for example, curcumin, coumarin, azo dyes, etc. Further, the present invention may further add other additives as needed, for example : Plasticizer, stabilizer, etc.

<Method of Forming Protrusion for Liquid Crystal Alignment Control>

The positive photosensitive resin composition of the present invention comprises a novolac resin (A), an ester of an o-naphthoquinonediazide sulfonic acid (B), and a solvent (C), which are uniformly mixed into a solution state in a stirrer, if necessary. Additives (D) such as adhesion aids, surfactants, diluents, compatible dyes, plasticizers, stabilizers, etc. may be added at the same time. Finally, the composition is applied onto a substrate by a roll coating method, a spin coating method, a cast coating method, an inkjet method, or the like. After coating, the solvent was removed by a prebake method to form a photosensitive composition layer. The pre-baking conditions vary depending on the type of each component and the blending ratio, and the temperature is usually between 90 and 110 ° C for 1 minute to 10 minutes. The film thickness of the photosensitive composition layer after prebaking is 1 to 3 μm.

After pre-baking, the photosensitive resin composition layer is interposed between the designated masks, exposed by a stepper (such as Nikon 1755G7A), and immersed in a developer at 23±2 ° C for 30 seconds to 5 minutes. The development is carried out, and the portion is removed without being partially removed. Light for exposure: UV rays such as g-line, h-line, and i-line are preferable, and the ultraviolet device can be (ultra) high mercury lamp and metal halide lamp.

The above-mentioned substrate is exemplified by an alkali-free glass, a soda-lime glass, a hard glass (Pyles glass), a quartz glass, or the like used for a liquid crystal display device or the like.

Further, the developer is used, for example, 0.1 to 5% by weight of tetramethyl ammonium hydroxide, sodium carbonate (Na ₂ CO ₃ ), sodium hydrogencarbonate (Na ₂ HCO ₃ ), sodium hydroxide ( NaOH), potassium hydroxide (KOH), and the like. When a developer composed of such an alkaline aqueous solution is used, it is usually washed with water after development.

Next, the pattern is air-dried by compressed air or compressed nitrogen, and then post-baked by a heating device such as a hot plate or an oven. The set temperature is 100~250°C, the heating plate is 2 minutes~60 minutes for the given time, and the oven is 2 minutes~90 minutes.

<Liquid crystal display element>

In the liquid crystal display device of the present invention, after the transparent conductive film and the alignment film are formed on the color filter substrate, the liquid crystal alignment control protrusion is formed by the above-described method for forming a liquid crystal alignment control protrusion, and a spacer is formed. After that, it is bonded to a driving substrate provided with a thin film transistor (TFT), injected with liquid crystal, and sealed with an injection hole to constitute a liquid crystal cell. Then, a polarizing plate is attached to the outer surface of the liquid crystal cell to obtain a liquid crystal display element.

The technical contents, features and effects of the present invention will be apparent from the following description of the embodiments and the comparative examples.

[Synthesis Example of Novolak Resin (A)] Synthesis Example A-1

A nitrogen inlet, a stirrer, a heater, a condenser and a thermometer were placed on a four-necked flask of 1000 ml volume, and nitrogen was introduced and the feed composition was added according to the amount shown in Table 1. The above feed composition included: - cresol 75.7 g (0.7 mol), p-cresol 32.4 g (0.3 mol), 37 wt% formaldehyde aqueous solution 52.8 g (formaldehyde 0.65 mol), oxalic acid 1.8 g (0.02 mol). When the contents of the four-necked flask were stirred, the temperature of the oil bath was raised to 100 °C. The reaction temperature of the polycondensation process was maintained at 100 ° C and the polycondensation time was 6 hours. After the completion of the polycondensation, the temperature was raised to 180 ° C and dried under reduced pressure at a pressure of 10 mmHg, and the solvent was devolatilized to obtain a novolak resin (A-1). The results of the molecular weight distribution measured by gel permeation chromatography of the obtained novolak resin (A-1) and the results of thermal weight loss measured by a thermogravimetric analyzer are shown in Table 2.

Synthesis Example A-2 to A-4

The operation method of the synthesis example A-1 differs from the type and amount of the aromatic hydroxy compound, the amount of the aldehyde, the amount of the acidic catalyst, and the reaction temperature. The formulation and reaction conditions are shown in Table 1. The results of the molecular weight distribution measured by gel permeation chromatography of the obtained novolac resin and the results of thermal weight loss measured by a thermogravimetric analyzer are shown in Table 2.

Synthesis Example A-5

100 parts by weight of the novolak resin (A-1) obtained in Synthesis Example 1 was dissolved in 300 parts by weight of a solvent of propylene glycol monomethyl ether acetate, and stirring was continued at room temperature until completely dissolved. Thereafter, the mixture was poured into 2000 parts by weight of ethylbenzene (Ethylbenzene), and stirring was continued for 30 minutes, and then the precipitate was taken out, and the solvent was devolatilized to obtain a novolak resin (A-5). The results of molecular weight distribution measured by gel permeation chromatography of the obtained novolak resin (A-5) and the results of thermal weight loss measured by a thermogravimetric analyzer are shown in Table 2.

Synthesis Example A-6

100 parts by weight of the novolak resin (A-2) obtained in Synthesis Example 2 was dissolved in 300 parts by weight of a solvent of propylene glycol monomethyl ether acetate, and stirring was continued at room temperature until completely dissolved. Thereafter, the mixture was poured into 1500 parts by weight of isopropylbenzene (Benzenebenzene), and stirring was continued for 30 minutes. Then, the precipitate was taken out, and the solvent was devolatilized to obtain a novolac resin (A-6). The results of the molecular weight distribution measured by gel permeation chromatography of the obtained novolac resin (A-6) and the results of thermal weight loss measured by a thermogravimetric analyzer are shown in Table 2.

Synthesis Example A-7

100 parts by weight of the novolak resin (A-3) obtained in Synthesis Example 3 was dissolved in 300 parts by weight of a solvent propylene glycol monomethyl ether acetate, and stirring was continued at room temperature until completely dissolved. Thereafter, the mixture was poured into 3000 parts by weight of ethylbenzene, and stirring was continued for 30 minutes. Then, the precipitate was taken out, and the solvent was devolatilized to obtain a novolak resin (A-7). The results of the molecular weight distribution measured by gel permeation chromatography of the obtained novolak resin (A-7) and the results of thermal weight loss measured by a thermogravimetric analyzer are shown in Table 2.

Synthesis Example A-8

100 parts by weight of the novolak resin (A-4) obtained in Synthesis Example 4 was dissolved in 300 parts by weight of a solvent propylene glycol monomethyl ether acetate, and stirring was continued at room temperature until completely dissolved. Thereafter, it is injected into 1500 parts by weight of ethylbenzene, and stirring is continued for 30 minutes, and then the precipitate is taken out, and after the solvent is devolatilized, the steps of dissolving, precipitating, and devolatilizing are repeated once to obtain a novolak resin (A-8). . The results of the molecular weight distribution measured by gel permeation chromatography of the obtained novolak resin (A-8) and the results of thermal weight loss measured by a thermogravimetric analyzer are shown in Table 2.

Synthesis Example A-9

100 parts by weight of the novolak resin (A-3) obtained in Synthesis Example 3 was dissolved in 300 parts by weight of a solvent propylene glycol monomethyl ether acetate, and stirring was continued at room temperature until completely dissolved. After injecting into 1000 parts by weight of cumene while stirring for 30 minutes, the precipitate is taken out, and after the solvent is devolatilized, the steps of dissolving, precipitating, and devolatilizing are repeated twice to obtain a novolak resin (A- 9). The results of the molecular weight distribution measured by gel permeation chromatography of the obtained novolac resin (A-9) and the thermal weight loss measured by a thermogravimetric analyzer are shown in Table 2. The weight average molecular weight of the resin was 9,800. .

Synthesis Example A-10

100 parts by weight of the novolak resin (A-4) obtained in Synthesis Example 3 was dissolved in 300 parts by weight of a solvent propylene glycol monomethyl ether acetate, and stirring was continued at room temperature until completely dissolved. Thereafter, the mixture was poured into a cosolvent of 1000 parts by weight of ethylbenzene/1000 parts by weight of cumene, and stirring was continued for 30 minutes, and then the precipitate was taken out, and the solvent was devolatilized to obtain a novolak resin (A-10). The results of the molecular weight distribution measured by gel permeation chromatography of the obtained novolak resin (A-10) and the results of thermal weight loss measured by a thermogravimetric analyzer are shown in Table 2.

[Examples and Comparative Examples of Photosensitive Resin Composition] Example 1

100 parts by weight of novolac resin A-7 shown in Table 2, esterified with 2,3,4-trihydroxybenzophenone and 1,2-naphthoquinonediazide-5-sulfonic acid (average degree of esterification) 85%, hereinafter referred to as B-1) 25 parts by weight, esterified with 2,3,4,4'-tetrahydroxybenzophenone and 1,2-naphthoquinonediazide-5-sulfonic acid (average ester 85% by weight, hereinafter referred to as B-2) 10 parts by weight, and a surfactant (trade name: SF8427, manufactured by Toray Dow Corning Silicone Co., Ltd.) 0.3 parts by weight dissolved in propylene glycol monomethyl ether acetate 1100 parts by weight of a solvent, which can be obtained. A positive photosensitive resin composition. The measurement evaluation methods described below were evaluated, and the results obtained are shown in Table 3.

[Evaluation method] (1) Determination of molecular weight distribution of novolak resin (A)

The novolac resin (A) was determined according to the GPC of the Waters Company by gel permeation chromatography, and was determined according to the following conditions:

Column: GP-501/502/503/504 (manufactured by Polymer Laboratories) Detector: Waters RI-2410 mobile phase: tetrahydrofuran (flow rate 1.0 ml/min) using standard molecular weight polystyrene as a measurement standard.

The molecular weight of the resin referred to in the present invention is determined by GPC, that is, in the measurement range of GPC, the total integrated area of the resin signal having a molecular weight of 200 to 150,000 is regarded as 100%, wherein the molecular weight is determined to be 200, respectively. ～400, and the content of the total resin (% by weight) of the molecular weight of 10,000 to 30,000.

(2) Thermal Gravimetric Analysis of Novolak Resin (A)

The novolac resin (A) was measured by a thermogravimetric analyzer (manufactured by TA Instruments, Model: 2850) under a nitrogen atmosphere at 230 ° C for 30 minutes to determine its thermal weight loss (% by weight).

(three) sensitivity

The photosensitive resin composition was spin-coated on a 6 吋 Si wafer substrate, and then prebaked at a temperature of 110 ° C for 1.5 minutes to form a pre-baked film having a film thickness of 1.5 μm. After further irradiation with a stepper (Nikon 1755G7A) at intervals of 1 ms, the solution was further immersed in a developing solution at 23 ° C for 1 minute to remove the exposed portion of the substrate, and washed with pure water. The sensitivity is estimated as the exposure time (milliseconds, ms) required for each exposure zone (0.5 cm x 0.5 cm) to be fully visible.

○: 25≦ exposure time ≦50

╳: Exposure time ≦25

(4) Afterimage

The photosensitive resin composition is applied to a color filter glass substrate having an alignment film and a transparent conductive film by spin coating, and then pre-baked at a temperature of 110 ° C for 1.5 minutes to form a film thickness. Pre-baked film of 1.5 μm. The pre-baked coating film is placed between the designated masks, irradiated with a light amount of 20 mJ/cm ² by a stepping machine (Nikon 1755G7A), and then immersed in a developing solution at 23 ° C for 1 minute to develop and expose the substrate. The part was removed, washed with pure water, and baked at 230 ° C for 30 minutes, thereby forming a projection for liquid crystal alignment control on the substrate.

The color filter glass substrate obtained by the above steps was coated with a thermocompression adhesive, and the other drive glass substrate having the thin film transistor was sprinkled with a spacer of 4 μm, and the two sheets of glass were bonded. After injecting the nematic liquid crystal, the liquid crystal injection port is sealed with ultraviolet (UV) hardening glue to form a liquid crystal cell.

After the obtained liquid crystal cell was applied at a DC voltage of 10 volts for 48 hours, when the voltage application was released, the presence or absence of image sticking on the display screen was visually observed.

○: No image sticking occurred.

╳: There is a phenomenon of afterimages.

Example 2

The operation method of the first embodiment differs from the type and amount of the novolak resin (A), the type and amount of the additive (D), and the formulation and evaluation results are shown in Table 3.

Example 3

The operation method of the first embodiment is different from the type and amount of the novolak resin (A), the amount of the ester of the o-naphthoquinone diazide sulfonic acid (B), the kind of the solvent (C), and the additive ( The type and amount of D), the formulation and evaluation results are shown in Table 3.

Example 4

The operation method of the first embodiment is different from the type and amount of the novolak resin (A), the amount of the ester of the o-naphthoquinone diazide sulfonic acid (B), the kind and amount of the solvent (C), The types of additives (D), their formulations and evaluation results are shown in Table 3.

Example 5

The operation method of Example 1 was different except that the type of the novolac resin (A) was changed, and the formulation and evaluation results are shown in Table 3.

Example 6

The operation method of the first embodiment differs from the type and amount of the novolak resin (A), the type and amount of the additive (D), and the formulation and evaluation results are shown in Table 3.

Example 7

The method of operation of Example 1 differs in that the type and amount of the novolac resin (A), the type and amount of the ester of the o-naphthoquinone diazide sulfonic acid (B), the type of the solvent (C), and The dosage and the type and amount of the additive (D), the formulation and evaluation results are shown in Table 3.

Example 8

The operation method of the first embodiment is different from the type and amount of the novolak resin (A), the type and amount of the ester of the o-naphthoquinone diazide sulfonic acid (B), and the amount of the solvent (C). And the additive (D) was not added, and the formulation and evaluation results are shown in Table 3.

Comparative example 1

The operation method of Example 1 was different except that the type of the novolac resin (A) was changed, and the formulation and evaluation results are shown in Table 3.

Comparative example 2

The operation method of the first embodiment differs from the type of the novolak resin (A), the type and amount of the additive (D), and the formulation and evaluation results are shown in Table 3.

Comparative example 3

The operation method of the first embodiment is different from the type of the novolac resin (A), the type and amount of the ester of the o-naphthoquinonediazidesulfonic acid (B), the kind and amount of the solvent (C), The types and amounts of additives (D), their formulations and evaluation results are shown in Table 3.

Comparative example 4

The operation method of the first embodiment is different from the type of the novolac resin (A), the type and amount of the ester of the o-naphthoquinonediazidesulfonic acid (B), the amount of the solvent (C), and the The additive (D) was added, and the formulation and evaluation results are shown in Table 3.

Comparative Example 5

The operation method of Example 1 was different except that the type of the novolac resin (A) was changed, and the formulation and evaluation results are shown in Table 3.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All should remain within the scope of the invention patent.

[Note to the attached table]

Table 1: Composition ratio of each synthesis example of the novolak resin (A) of the present invention.

Table 2: Molecular weight distribution of each of the synthetic examples of the novolac resin (A) of the present invention, and the results of thermogravimetric loss.

Table 3: Composition ratios and evaluation results of the respective examples and comparative examples of the photosensitive resin composition of the present invention.

Claims (5)

A positive photosensitive resin composition comprising: a novolac resin (A); an esterified sensitizer (B) of o-naphthoquinonediazidesulfonic acid; and a solvent (C); wherein the novolak resin (A) The molecular weight measured by the gel permeation chromatography method is less than 150,000, and the total integrated area of the resin signal having a molecular weight of 200 to 150,000 is regarded as 100% by weight, and the molecular weight thereof is between 200 and 400. ~4% by weight, the molecular weight of 10,000-30,000 is more than 12% by weight; and the novolac resin (A) is analyzed by a thermogravimetric analyzer, and the thermal weight loss is 10% by weight at 230 ° C for 30 minutes. the following. The positive photosensitive resin composition according to the first aspect of the invention, wherein the total integrated area of the resin signal having a molecular weight of 200 to 150,000 is regarded as 100% by weight, and the molecular weight thereof is between 200 and 400. 0.05~2% by weight. A projection for liquid crystal alignment control, which is characterized in that it is formed of a positive photosensitive resin composition as described in claim 1 of the patent application. A method for producing a projection for liquid crystal alignment control, which is characterized in that a positive photosensitive resin composition as described in claim 1 of the patent application is formed by coating, exposing, and developing a substrate. A liquid crystal display element comprising the liquid crystal alignment control protrusion according to the second aspect of the patent application.