JP2010091984A - Negative-type resist for forming protrusion for liquid crystal alignment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a negative-type resist for forming a protrusion for liquid crystal alignment that forms a protrusion for controlling the liquid crystal alignment of a liquid crystal display, and prevents a liquid crystal burning phenomenon from occurring in the manufactured liquid crystal display. <P>SOLUTION: This negative-type resist for forming the protrusion for liquid crystal alignment contains alkali-soluble resin, polymerization monomer and photopolymerization initiator, and is used for forming the protrusion for liquid crystal alignment of an MVA (Multidomain Vertical Alignment) type liquid crystal display. The polymerization monomer contains novolac epoxy (meth) acrylate with a hydroxyl group amount of 15-70 mol%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a negative resist for forming protrusions for liquid crystal alignment, which can form protrusions for controlling the liquid crystal alignment of a liquid crystal display device and can prevent the occurrence of liquid crystal burn-in phenomenon in the manufactured liquid crystal display device.

The liquid crystal display device has a structure in which liquid crystal aligned in a direction perpendicular or parallel to the substrate is injected between two substrates on which a color filter, a black matrix, a linear transparent electrode, an alignment film, and the like are formed. Have. The liquid crystal injected between the substrates is aligned in the direction perpendicular or parallel to the substrate in the absence of an electric field, but the alignment state changes with the application of an electric field, and the amount of light transmitted through the liquid crystal. Can be adjusted.

A liquid crystal display device has been put to practical use as a liquid crystal television used for a large screen television because it is thin and consumes less power than a display device using a conventional cathode ray tube. However, the liquid crystal display element has a problem that the viewing angle is narrower than a display device using a cathode ray tube. With the widespread use of large-screen LCD TVs, there has been a strong demand for improved viewing angles.

As a method of improving the viewing angle of a liquid crystal display device, an arch-shaped protrusion is formed on a transparent electrode, the liquid crystal is locally tilted using the slope of this protrusion, and the liquid crystal is divided and aligned in multiple directions within one pixel. A so-called MVA (Multidomain Vertical Alignment) method has been proposed.
As a method of forming the arch-shaped protrusion formed on the transparent electrode, a protrusion having a substantially rectangular cross section is formed by a photolithographic technique using a positive resist, and then the protrusion is heated and reflowed. There is known a method of making it arched. As a positive resist used to form arch-shaped protrusions on a transparent electrode, for example, Patent Document 1 discloses a composition containing a naphthoquinonediazide compound and a copolymer containing a specific structural unit having a hydroxyl group. Has been.

However, when a protrusion is formed on a transparent substrate using a positive resist, a process of reflowing into an arch shape is essential, so the arch of the protrusion to be obtained depends on the bottom width of the pattern to be formed and the heating temperature. There has been a problem that the height of the shape, the angle of contact with the substrate, and the like are different. If the heights and angles of the protrusions are different, liquid crystal alignment unevenness and display unevenness occur. In addition, the positive resist disclosed in Patent Document 1 has a problem in that the unreacted naphthoquinone diazite and a copolymer containing a specific structural unit having a hydroxyl group undergo a coupling reaction by heating, causing the resist to turn red. It was. In addition, the positive resist disclosed in Patent Document 1 develops a difference in solubility in an alkali developer between an exposed area and an unexposed area by an alkali-soluble carboxylic acid generated by photolysis of naphthoquinonediazide. For this reason, the development condition margin is narrower than that of the negative resist and the development state is difficult to manage, such as development deterioration due to oxygen in the air. Further, the manufacturing process of the liquid crystal display device includes a process using various resists in addition to the process of forming protrusions on the transparent electrode, and most of them use a negative resist. The use of a positive resist only in the process of forming protrusions has caused the manufacturing process to become complicated.

On the other hand, Patent Document 2 discloses providing protrusions on an electrode using a negative resist mainly composed of an alkali-soluble resin, a photopolymerization initiator, and a photopolymerizable monomer. Patent Document 3 discloses a photosensitive resin composition mainly composed of an ethylenically unsaturated compound, a photopolymerization initiator, and an alkali-soluble resin as a negative resist for forming liquid crystal split alignment protrusions. . It is considered that the use of these negative resists can simplify the production of the liquid crystal display device.
However, in the liquid crystal display device in which the liquid crystal alignment protrusions are formed using the conventional negative resist, when the liquid crystal alignment protrusions are formed for a long time, the liquid crystal is abnormally aligned and the display image is burned. There was a problem that the liquid crystal burn-in phenomenon occurred.
JP-A-7-92689 JP 2003-330011 A JP 2006-11359 A

The present invention provides a negative resist for forming protrusions for liquid crystal alignment, which can form protrusions for controlling the liquid crystal alignment of the liquid crystal display device and can prevent the occurrence of liquid crystal burn-in phenomenon in the manufactured liquid crystal display device. The purpose is to do.

The present invention is a negative resist used for forming projections for liquid crystal alignment of an MVA liquid crystal display device, which contains an alkali-soluble resin, a polymerizable monomer, and a photopolymerization initiator, The body is a negative resist for forming liquid crystal alignment protrusions containing novolak epoxy (meth) acrylate having a hydroxyl group content of 15 to 70 mol%.
The present invention is described in detail below.

The present inventors use a negative resist containing a novolac epoxy (meth) acrylate as a polymerizable monomer and a protrusion for dividing and aligning the liquid crystal of an MVA liquid crystal display device in multiple directions within one pixel. It has been found that even when the display is performed for a long period of time, abnormal alignment of liquid crystal does not occur in the projection formation portion, and the liquid crystal burn-in phenomenon does not occur. As a result of further investigation, when novolak epoxy (meth) acrylate having a certain amount of hydroxyl group is used, it is possible to simultaneously achieve high developability and heat resistance required for a negative resist. The headline and the present invention were completed.

The negative resist for forming projections for liquid crystal alignment of the present invention (hereinafter also referred to as negative resist of the present invention) is formed on a substrate for partially dividing and aligning liquid crystals in an MVA liquid crystal display device. This is for forming arch-shaped protrusions (liquid crystal alignment protrusions). Note that the negative resist of the present invention can be used to manufacture, for example, a column spacer that regulates a gap between two substrates of a liquid crystal display device in addition to the liquid crystal alignment protrusion.

The negative resist of the present invention contains an alkali-soluble resin, a polymerizable monomer, and a photopolymerization initiator.
The polymerizable monomer is a cross-linking component that cross-links an alkali-soluble resin described later by light irradiation to the negative resist of the present invention. By using novolak epoxy (meth) acrylate as the polymerizable monomer, the MVA type liquid crystal display device provided with the liquid crystal alignment protrusion using the negative resist of the present invention suppresses the occurrence of the liquid crystal burn-in phenomenon. it can. The reason for this is considered as follows.

The liquid crystal burn-in phenomenon that occurs in the MVA type liquid crystal display device is considered to be caused by a residual electric field generated between the protrusion formation portion and the counter substrate. This residual electric field is thought to have been caused by the large difference between the dielectric loss tangent of the protrusion and the dielectric loss tangent of the alignment film and the liquid crystal. The protrusion for liquid crystal alignment formed using the negative resist of the present invention containing novolak epoxy (meth) acrylate as the polymerizable monomer has a dielectric loss tangent close to that of the alignment film and the liquid crystal. It is considered that the generation of an electric field can be prevented. Therefore, it is considered that the MVA type liquid crystal display device having the liquid crystal alignment protrusions formed using the negative resist of the present invention does not cause a liquid crystal burn-in phenomenon even when displaying for a long time.

The novolak epoxy (meth) acrylate is not particularly limited. For example, phenol novolac epoxy (meth) acrylate, 0-cresol novolac epoxy (meth) acrylate, m-cresol novolac epoxy (meth) acrylate, p-cresol novolac epoxy ( Examples include meth) acrylate, naphthol-modified novolac epoxy (meth) acrylate, and halogenated phenol novolac epoxy (meth) acrylate.
In the present specification, (meth) acrylate means acrylate or methacrylate.
The general formula representing the novolak epoxy (meth) acrylate is shown in the following formula (1).

In Formula (1), R ¹ and R ² represent hydrogen or a methyl group, and m represents 0 or a positive integer.

The novolak epoxy (meth) acrylate has a lower limit of 15 mol% of the amount of hydroxyl groups and an upper limit of 70 mol%. When the hydroxyl group content of the novolak epoxy (meth) acrylate is less than 15 mol%, the developability is inferior, and when it exceeds 70 mol%, the heat resistance is inferior.
The hydroxyl group content of the novolac epoxy (meth) acrylate can be adjusted by adjusting the degree of (meth) acrylate modification.

The novolak epoxy (meth) acrylate having a hydroxyl group content of 15 to 70 mol% is a method of adding (meth) acrylic acid to a hydroxyl group while leaving the hydroxyl group of the novolak resin having a hydroxyl group, or a novolac epoxy resin ( It can be produced by a method in which an epoxy group is opened by adding (meth) acrylic acid to generate a hydroxyl group.

As a method of opening an epoxy group by adding (meth) acrylic acid to the above novolak epoxy resin to form a hydroxyl group, novolac epoxy resin and (meth) acrylic acid are used in the presence of a basic catalyst according to a conventional method. And the like. An epoxy resin having a desired acrylate ratio can be obtained by appropriately changing the mixing ratio of the novolac epoxy resin to be reacted and (meth) acrylic acid.

Among the raw materials of the above (meth) acrylic acid-modified epoxy resin, for example, as a phenol novolak type, Epicron N-740, Epicron N-770, Epicron N-775 (above, Dainippon Ink and Chemicals, Inc.) Manufactured by the company), Epicoat 152, Epicoat 154 (manufactured by Japan Epoxy Resin Co., Ltd.). -680, Epicron N-695, Epicron N-665-EXP, Epicron N-672-EXP (above, manufactured by Dainippon Ink & Chemicals, Inc.) and the like.

Examples of the reaction include a method of reacting the novolak epoxy resin and (meth) acrylic acid at a temperature of 30 to 150 ° C. in the presence of a stabilizer such as an epoxy esterification catalyst, a polymerization inhibitor, and an antioxidant. It is done.
Examples of the esterification catalyst include tertiary amines, imidazole compounds, phosphorus compounds, and organic metals.
Examples of the polymerization inhibitor include hydroquinone, methylhydroquinone, 4-methoxyphenol and the like.
Examples of the antioxidant include phosphites, phosphites, phosphites and the like.

The novolac epoxy (meth) acrylate preferably has an alkali-soluble functional group. By having an alkali-soluble functional group, the developability of the resulting negative resist of the present invention is improved. The alkali-soluble functional group can be introduced by reacting a polybasic acid anhydride with a hydroxyl group contained in the novolak epoxy (meth) acrylate. As the reaction method, for example, it can be obtained by continuing the reaction under the same conditions as in the esterification reaction.
A general formula representing the novolak epoxy (meth) acrylate having the alkali-soluble functional group is shown in the following formula (2).

In formula (2), R ¹ and R ² represent hydrogen or a methyl group, and R ³ represents an atomic group derived from a polybasic acid anhydride and having a carboxyl group. M and n represent 0 or a positive integer.

Examples of the polybasic acid anhydride include succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, itaconic anhydride, pyromellitic anhydride, trimellitic anhydride, and the like. It is done. Of these, succinic anhydride or phthalic anhydride is preferred from the viewpoint of reactivity.

When the said novolak epoxy (meth) acrylate has an alkali-soluble functional group, the preferable upper limit of the oxidation is 250 mgKOH / g. When the oxidation of the novolak epoxy (meth) acrylate having an alkali-soluble functional group exceeds 250 mgKOH / g, the adhesion may be lowered. The upper limit with more preferable oxidation of the novolak epoxy (meth) acrylate which has the said alkali-soluble functional group is 200 mgKOH / g.

The novolak epoxy (meth) acrylate has a preferable lower limit of 600 and a preferable upper limit of 2000 for the weight average molecular weight. If the weight average molecular weight of the novolak epoxy (meth) acrylate is less than 600, the amount of unreacted low molecular weight compound in the resin increases, and the remaining low molecular weight compound elutes in the liquid crystal, resulting in poor panel display. If it exceeds 2000, a residue may be generated during development, and the resulting protrusion may not be arched. The more preferable lower limit of the weight average molecular weight of the novolak epoxy (meth) acrylate is 800, and the more preferable upper limit is 1800.
In the present invention, the weight average molecular weight of the novolak epoxy (meth) acrylate is measured by a gel permeation chromatography (GPC) method using tetrahydrofuran as a developing solvent using a column such as Shodex LF-804 manufactured by Showa Denko KK, for example. And a value obtained by polystyrene conversion.

As a commercial item of the said novolak epoxy (meth) acrylate, for example, EA-1020, EA-1025, EA-1026, EA-1028, EA-6320, EA-6340 (all are made by Shin-Nakamura Chemical Co., Ltd.) , Ebecryl 150, Ebecryl 1150 (all are manufactured by Daicel UCB), M-208, M-210 (all are manufactured by Toa Gosei Co., Ltd.), PNA-161H, CNA-142H, PCR-1169H, CCR -1159H (all above, manufactured by Nippon Kayaku Co., Ltd.), Epicron N-695, Epicron N-775 (all above, manufactured by Dainippon Ink & Chemicals), PR-300, PR-310, PR-320, HRM- 1004, HRM-1005, HRM-1011, HRM-1013, HRM-2019, HRM-2021, HRM-2027, HRM-2031 (all of which are manufactured by Showa Polymer Co., Ltd.) and the like.

The blending amount of the novolac epoxy (meth) acrylate is not particularly limited, but a preferred lower limit is 20 parts by weight and a preferred upper limit is 200 parts by weight with respect to 100 parts by weight of the alkali-soluble resin. When the amount of the novolac epoxy (meth) acrylate is less than 20 parts by weight, the effect of preventing burn-in may be impaired, and when it exceeds 200 parts by weight, the development dissolution rate may be easily lowered. is there. A more preferable lower limit of the compounding amount of the novolak epoxy (meth) acrylate is 30 parts by weight, and a more preferable upper limit is 180 parts by weight.

The negative resist of the present invention has a polymerizable property other than the above-described novolak epoxy (meth) acrylate for the purpose of improving adhesion, developability, heat resistance, acid resistance, alkali resistance, chemical resistance, and compatibility with alkali-soluble resins. A monomer may be contained. The polymerizable monomer means a compound having one or more ethylenically unsaturated bonds in the molecule.

The compound having one ethylenically unsaturated bond in the molecule is not particularly limited, and examples thereof include unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, isocrotonic acid, maleic acid, itaconic acid, citraconic acid and the like. Examples thereof include alkyl esters, (meth) acrylonitrile, (meth) acrylamide, styrene and the like.

The compound having two ethylenically unsaturated bonds in the molecule is not particularly limited. For example, neopentyl glycol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, 2-butyl 2-ethyl-1,3-propanediol di (meth) acrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, hydroxypivalic acid neopentyl glycol ester diacrylate, diethylene glycol (meth) acrylate , Polyethylene glycol (meth) acrylates such as triethylene glycol (meth) acrylate, tetraethylene glycol (meth) acrylate, hexaethylene glycol (meth) acrylate and nonaethylene glycol (meth) acrylate , Polyethylene glycol di (meth) acrylate such as diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, hexaethylene glycol di (meth) acrylate, nonaethylene glycol di (meth) acrylate ) Acrylate and the like.

The compound having three or more ethylenically unsaturated bonds in the molecule is not particularly limited. For example, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, Multifunctional (meth) acrylates such as pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate Compounds and the like. A compound having 3 or more of these ethylenically unsaturated bonds in the molecule is particularly suitable because the polymerization reaction proceeds rapidly and the exposure sensitivity is easily improved. Of these, pentaerythritol tri (meth) acrylate is preferred because it improves developability and compatibility with alkali-soluble resins.
These polymerizable monomers may be used independently and 2 or more types may be used together.

When a polymerizable monomer other than the novolak epoxy (meth) acrylate is used in combination, a preferred upper limit of the ratio of the polymerizable monomer other than the novolak epoxy (meth) acrylate to the entire polymerizable monomer is 80 wt. %. When the ratio of the polymerizable monomer other than the novolak epoxy (meth) acrylate exceeds 80% by weight, the burn-in preventing effect may be impaired. The upper limit with more preferable ratio of polymerizable monomers other than the said novolak epoxy (meth) acrylate is 75 weight%.

The negative resist of the present invention contains an alkali-soluble resin.
Although it does not specifically limit as said alkali-soluble resin, What has a polymerizable double bond in a molecule | numerator is used suitably. Specific examples include alkali-soluble carboxyl group-containing polymer compounds such as copolymers obtained by copolymerizing a carboxyl group-containing monofunctional unsaturated compound and a monofunctional compound having an unsaturated double bond.

The carboxyl group-containing monofunctional unsaturated compound is not particularly limited, and examples thereof include acrylic acid and methacrylic acid.
The monofunctional compound having an unsaturated double bond is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (meth ) 2-ethylhexyl acrylate, hydroxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-methylcyclohexyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, isobornyl (meth) acrylate And (meth) acrylic acid ester monomers such as (meth) acrylic acid dicyclopentanyl and (meth) acrylic acid benzyl.

The alkali-soluble carboxyl group-containing polymer compound includes aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, and p-chlorostyrene, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, , Unsaturated dicarboxylic anhydrides such as maleic anhydride, aromatic substituted maleimides such as phenylmaleimide, benzylmaleimide, naphthylmaleimide, o-chlorophenylmaleimide, and alkyl substitutions such as methylmaleimide, ethylmaleimide, propylmaleimide, isopropylmaleimide A component derived from maleimide or the like may be contained.

The alkali-soluble carboxyl group-containing polymer compound may contain a component derived from a monofunctional unsaturated compound having a hydroxyl group for the purpose of controlling solubility during development.
The monofunctional unsaturated compound having a hydroxyl group is not particularly limited, and examples of the monomer having one hydroxyl group in the molecule include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, Examples include 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate.

In the alkali-soluble carboxyl group-containing polymer compound, the preferred lower limit of the ratio of components derived from the carboxyl group-containing monofunctional unsaturated compound is 5% by weight, and the preferred upper limit is 50% by weight. If the ratio of the component derived from the carboxyl group-containing monofunctional unsaturated compound is less than 5% by weight, it is difficult to impart alkali solubility, and if it exceeds 50% by weight, the swelling during development is remarkably patterned. Formation may be difficult. The more preferable lower limit of the ratio of the component derived from the carboxyl group-containing monofunctional unsaturated compound is 10% by weight, and the more preferable upper limit is 40% by weight.

The method for copolymerizing the carboxyl group-containing monofunctional unsaturated compound and the monofunctional compound having an unsaturated double bond is not particularly limited. For example, using a radical polymerization initiator and, if necessary, a molecular weight regulator. And polymerizing by a conventionally known method such as bulk polymerization, solution polymerization, suspension polymerization, dispersion polymerization, and emulsion polymerization. Of these, solution polymerization is preferred.

Examples of the solvent for producing the alkali-soluble carboxyl group-containing polymer compound by solution polymerization include aliphatic alcohols such as methanol, ethanol, isopropanol and glycol, cellosolves such as cellosolve and butylcellosolve, and carbitol. , Carbitols such as butyl carbitol, esters such as cellosolve acetate, carbitol acetate, propylene glycol monomethyl ether acetate, ethers such as diethylene glycol dimethyl ether, cyclic ethers such as tetrahydrofuran, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone And other polar organic solvents such as dimethyl sulfoxide and dimethylformamide can be used.

In addition, as a medium for producing the alkali-soluble carboxyl group-containing polymer compound by non-aqueous dispersion polymerization such as suspension polymerization, dispersion polymerization, emulsion polymerization, etc., for example, liquid such as benzene, toluene, hexane, cyclohexane, etc. Hydrocarbons and other nonpolar organic solvents can be used.

It does not specifically limit as said radical polymerization initiator, For example, conventionally well-known radical polymerization initiators, such as a peroxide and an azo initiator, can be used. Moreover, as said molecular weight regulator, (alpha) -methylstyrene dimer, a mercaptan-type chain transfer agent, etc. can be used, for example.

In the negative resist of the present invention, the alkali-soluble resin is preferably an alkali-soluble (meth) acrylic copolymer having a (meth) acryl group and a carboxyl group in the side chain. When an alkali-soluble (meth) acrylic copolymer having a (meth) acrylic group and a carboxyl group in the side chain is selected as the alkali-soluble resin, the negative resist of the present invention has high sensitivity, and The cured liquid crystal alignment protrusions are excellent in resolution and adhesion to the substrate. The reason for this is considered to be that peeling of the pattern is suppressed as a result of the acrylic group in the side chain of the alkali-soluble resin reacting during exposure and the alkali-soluble resin itself being taken into the crosslinked structure.
The alkali-soluble (meth) acrylic copolymer has excellent compatibility with other components of the negative resist of the present invention because the polarity of the segment is low. As a result, problems such as development unevenness do not occur in the development process during the production of the liquid crystal alignment protrusions.

As the alkali-soluble (meth) acrylic copolymer, a copolymer composed of structural units represented by the following formulas (3a), (3b), (3c), (3d) and (3e) is preferable.

In formulas (3a), (3b), (3c), (3d) and (3e), A ¹ and A ² represent hydrogen, the following formulas (4a), (4b), (4c) or (4d) , A ¹ or A ² is hydrogen, the other is any of the following formulas (4a), (4b), (4c) or (4d). R ⁴ represents hydrogen and / or a methyl group, R ⁵ represents a phenyl group including an alkyl group, a phenyl group, an alkyl group or an alkoxy group, a hydroxyalkyl group or an alicyclic hydrocarbon, and R ⁶ represents a nitrile. R ⁷ represents an alkyl group, a hydroxyalkyl group or a radically polymerizable group-containing aliphatic hydrocarbon. Moreover, a, b, c, d, and e represent the molar ratio (%) of each component, and when a + b + c + d + e = 100, a, b and d are 0 to 90, c is 5 to 50, and e is 5 ~ 60.

Although it does not specifically limit as a weight average molecular weight of the said alkali-soluble (meth) acryl copolymer, A preferable minimum is 3000 and a preferable upper limit is 100,000. If the weight-average molecular weight of the alkali-soluble (meth) acrylic copolymer is less than 3000, the adhesion of the resulting liquid crystal alignment protrusions may decrease, and if it exceeds 100,000, the resolution may decrease. . A more preferred lower limit is 5000, and a more preferred upper limit is 50,000.
In addition, in this specification, the said weight average molecular weight is a value calculated | required by polystyrene conversion, measuring with gel permeation chromatography.

Although it does not specifically limit as a manufacturing method of the said alkali-soluble (meth) acryl copolymer, For example, an alicyclic epoxy group containing unsaturated compound is ring-opened to the (meth) acryl copolymer which has a carboxyl group in a side chain. A method in which a part of the carboxyl group is modified by addition polymerization, and further, an isocyanate compound, an epoxy compound, a lactone compound, an alcohol compound, or the like is reacted with a hydroxyl group generated by modification and / or a part of the remaining carboxyl group. Can be mentioned.

The method for producing the (meth) acrylic copolymer having a carboxyl group in the side chain is not particularly limited. For example, a carboxyl group-containing monofunctional unsaturated compound and a (meth) acrylic acid ester monomer are used as radicals. Examples thereof include a method of copolymerization by a conventionally known method such as bulk polymerization, solution polymerization, suspension polymerization, dispersion polymerization or emulsion polymerization using a polymerization initiator and, if necessary, a molecular weight adjusting agent.

Although it does not specifically limit as said alicyclic epoxy group containing unsaturated compound, For example, 3, 4- epoxy cyclohexyl (meth) acrylate etc. are used suitably.

Although it does not specifically limit as said isocyanate compound, For example, C2-C18 alkyl isocyanate and polymeric group containing isocyanate are used suitably. When the polymerizable group-containing isocyanate is used, the sensitivity during photocuring is increased, and various physical properties such as heat resistance, chemical resistance, and tack-free property are further improved.
Although it does not specifically limit as said polymerizable group containing isocyanate, For example, it is preferable to use what the (meth) acryloyl group couple | bonded with the isocyanate group through the C2-C6 alkylene group. Specifically, for example, 2-acryloyloxyethyl isocyanate, 2-methacryloylethyl isocyanate, 2-acryloylethyl isocyanate and the like can be mentioned, and 2-methacryloylethyl isocyanate and 2-acryloylethyl isocyanate are respectively Karenz MOI, And it is marketed as Karenz AOI (all are made by Showa Denko KK).

The method of reacting the isocyanate compound with the (meth) acrylic copolymer having a hydroxyl group and / or a carboxyl group in the side chain generated by the modification is not particularly limited, and the isocyanate compound is added in the presence of a small amount of the catalyst. The method of dripping or mixing in the solution of the (meth) acryl copolymer which has a hydroxyl group and / or a carboxyl group in the side chain produced by modification | denaturation is mentioned.
The catalyst used in this case is not particularly limited, and examples thereof include lauric acid and dibutyltin.
If necessary, a polymerization inhibitor such as p-methoxyphenol, hydroquinone, naphthylamine, tert-butylcatechol, 2,3-di-tert-butyl-p-cresol may be used.
Furthermore, for the purpose of suppressing thickening and the like, treatment with an alcohol such as methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, decanol or the like may be performed.

When an isocyanate compound is reacted with a (meth) acrylic copolymer having a hydroxyl group and a carboxyl group in the side chain generated by the modification according to the above production method, a structural unit represented by the formula (4b) is formed. .

It does not specifically limit as said epoxy compound, For example, a C2-C18 alkyl epoxy compound, a C2-C18 alkoxy epoxy compound, and a polymeric group containing epoxy compound are mentioned.

When the polymerizable group-containing epoxy compound is used as the epoxy compound, it is possible to realize improvement in various physical properties such as an increase in sensitivity during photocuring, heat resistance, chemical resistance, and tack-free property.
Although it does not specifically limit as said polymerizable group containing epoxy compound, For example, the (meth) acryloyl group couple | bonded with the epoxy group through the C2-C6 alkylene group is preferable. Specifically, glycidyl (meth) acrylate etc. are mentioned, for example.

The method for reacting the epoxy compound with a (meth) acrylic copolymer having a hydroxyl group and / or a carboxyl group in the side chain generated by the modification is not particularly limited, and the epoxy compound is added in the presence of a small amount of catalyst. The method of dripping or mixing in the solution of the (meth) acryl copolymer which has a hydroxyl group and / or a carboxyl group in the side chain produced by modification | denaturation is mentioned.
The catalyst used in this case is not particularly limited. For example, triethylamine, tripromylamine, tetramethylethylenediamine, dimethyllaurylamine, triethylbenzylammonium chloride, trimethylcetylammonium bromide, tetrabutylammonium bromide, trimethylbutylphosphonium bromide, tetra And butylphosphonium bromide.
If necessary, a polymerization inhibitor such as p-methoxyphenol, hydroquinone, naphthylamine, tert-butylcatechol, 2,3-di-tert-butyl-p-cresol may be used.

When an epoxy compound is reacted with a (meth) acrylic copolymer having a hydroxyl group and / or a carboxyl group in the side chain produced by the modification according to the above production method, it is represented by the formulas (4c) and (4d). A structural unit is formed.

When the above-mentioned isocyanate compound, epoxy compound, lactone compound, alcohol compound or the like is reacted with the (meth) acrylic copolymer having a hydroxyl group and / or a carboxyl group in the side chain produced by the modification, the (meth) acrylic compound is reacted. Of the hydroxyl groups contained in the copolymer, an amount corresponding to 0 to 100 mol% can be reacted.

Further, when the above-mentioned isocyanate compound, epoxy compound, lactone compound, alcohol compound or the like is reacted with a (meth) acrylic copolymer having a hydroxyl group and / or a carboxyl group in the side chain generated by modification, the above (meth) acrylic is reacted. Among the carboxyl groups contained in the copolymer, an amount corresponding to 0 to 90 mol% can be reacted. If it exceeds 90 mol%, the amount of the remaining carboxyl groups becomes too small, so that alkali solubility is impaired and developability may be lowered.

In the above formulas (3a), (3b), (3c), (3d) and (3e), a, b, c, d and e represent the molar ratio (%) of each component, and when a + b + c + d + e = 100 , A, b and d have a lower limit of 0% and an upper limit of 90%. The lower limit of c is 5%, and the upper limit is 50%. The lower limit of e is 5%, and the upper limit is 60%. The lower limit of c is 5%, and the upper limit is 50%. However, when the molar ratio of the carboxyl group-containing structural unit is less than 5%, it is difficult to impart alkali solubility. If it exceeds 50%, the swelling during development is remarkable and it becomes difficult to form a pattern. Further, the preferable lower limit of e is 5%, and the preferable upper limit is 60%. However, if it is less than 5%, the incorporation of the alkali-soluble resin into the crosslinked structure becomes insufficient and the crosslinking density is lowered. The deviation becomes too large, causing variations in the height of the liquid crystal alignment protrusions. If it exceeds 60%, the crosslinking density of the crosslinked structure becomes too high, making it difficult to stably form an arched shape.

Furthermore, in the negative resist of the present invention, the alkali-soluble resin preferably has an aromatic ring in the molecule. By containing an alkali-soluble resin having an aromatic ring, the dielectric loss tangent of the liquid crystal alignment protrusions can be further lowered, and the display of the liquid crystal display device having the liquid crystal alignment protrusions using the negative resist of the present invention is lengthened. It is possible to more suitably prevent the liquid crystal burn-in phenomenon from occurring when the time is taken.
The alkali-soluble resin having an aromatic ring is not particularly limited, but a benzyl (meth) acrylate copolymer is preferable because of good adhesion and developability.

In the negative resist of the present invention, the lower limit of the acid value of the alkali-soluble resin is preferably 50 mgKOH / g. When the acid value of the alkali-soluble resin is less than 50 mgKOH / g, the resolution of the negative resist of the present invention is deteriorated, and the arch-shaped liquid crystal alignment protrusions cannot be stably formed. is there. Although it does not specifically limit as an upper limit of the acid value of the said alkali-soluble resin, A preferable upper limit is 150 mgKOH / g. When the acid value of the alkali-soluble resin exceeds 150 mgKOH / g, the adhesion of the liquid crystal alignment protrusions using the negative resist of the present invention to the substrate may be lowered. The more preferable lower limit of the acid value of the alkali-soluble resin is 60 mgKOH / g, and the more preferable upper limit is 140 mgKOH / g.
In the present specification, the acid value of the alkali-soluble resin is defined as mg of potassium hydroxide required for neutralization when 1 g of the alkali-soluble resin is dissolved in an organic solvent and titrated with potassium hydroxide using phenolphthalein as an indicator. Indicated by a number.

The content of the alkali-soluble resin in the negative resist of the present invention is usually 25% by weight or more, preferably 30% by weight or more, and usually 90% by weight or less, preferably 80% by weight, based on the total solid content. It is as follows. If the amount of the alkali-soluble resin is too small, the heat resistance and the development dissolution rate are likely to be lowered. If the amount is too large, the sensitivity is lowered and the reproducibility of the image cross-sectional shape is likely to be poor.

The negative resist of the present invention has a specific ratio between the content of the alkali-soluble resin and the content of the polymerizable monomer described above in order to stabilize the height of the liquid crystal alignment protrusions and the shape in contact with the substrate. Preferably there is. Specifically, the preferred lower limit of the weight ratio of (alkali-soluble resin content) / (polymerizable monomer content) is 0.25, the preferred upper limit is 3.5, and the more preferred lower limit is 0.00. 35, the more preferred upper limit is 3.

The negative resist of the present invention contains a photopolymerization initiator.
The photopolymerization initiator is not particularly limited and includes conventionally known photopolymerization initiators, such as a compound capable of generating a radical that polymerizes an ethylenically unsaturated group by ultraviolet light, and a compound that generates an acid by ultraviolet light. Can be mentioned.

Specific examples of the photopolymerization initiator include, for example, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxynaphthyl) -4,6-bis. (Trichloromethyl) -s-triazine, 2- (4-ethoxynaphthyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-ethoxycarbonylnaphthyl) -4,6-bis (trichloromethyl) ) -S-triazine and other halomethylated triazine derivatives, halomethylated oxadiazole derivatives, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5 -Bis (3'-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2 Imidazole derivatives such as (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, benzoin methyl ether, benzoin phenyl ether, benzoin Benzoin such as isobutyl ether and benzoin isopropyl ether, benzoin alkyl ethers, anthraquinone derivatives such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone and 1-chloroanthraquinone, benzanthrone derivatives, benzophenone, Michler's ketone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2-chlorobenzophenone, 4-bromobenzophenone, 2-carboxybenzophene Benzophenone derivatives such as 1,2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, α-hydroxy-2-methylphenylpropanone, 1-hydroxy-1 -Methylethyl- (p-isopropylphenyl) ketone, 1-hydroxy-1- (p-dodecylphenyl) ketone, 2-methyl- (4 '-(methylthio) phenyl) -2-morpholino-1-propanone, 1, Acetophenone derivatives such as 1,1, -trichloromethyl- (p-butylphenyl) ketone, thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethyl Thioxanthone, 2,4-di Thioxanthone derivatives such as sopropylthioxanthone, benzoic acid ester derivatives such as ethyl p-dimethylaminobenzoate and ethyl p-diethylaminobenzoate, acridine derivatives such as 9-phenylacridine and 9- (p-methoxyphenyl) acridine, Phenazine derivatives such as 9,10-dimethylbenzphenazine, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis -2,3,4,5,6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopenta Dienyl-Ti-bis-2,4,6-trifluorophen-1-yl, di-cyclopentadiene Ru-Ti-2,6-di-fluorophen-1-yl, di-cyclopentadienyl-Ti-2,4-di-fluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis -2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,6-di-fluorophen-1-yl, di-cyclopentadienyl -Ti-2,6-di-fluoro-3- (pyr-1-yl) -phen-1-yl and other titanocene derivatives and 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopro Pan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butane-1 -ON, 4- Dimethylaminoethyl benzoate, 4-dimethylaminoisoamyl benzoate, 4-diethylaminoacetophenone, 4-dimethylaminopropiophenone, 2-ethylhexyl-1,4-dimethylaminobenzoate, 2,5-bis (4 -Diethylaminobenzal) cyclohexanone, 7-diethylamino-3- (4-diethylaminobenzoyl) coumarin, α-aminoalkylphenone compounds such as 4- (diethylamino) chalcone, 1,2-octanedione, 1- [4- (Phenylthio) phenyl]-, 2- (O-benzoyloxime), ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyl) Oxime derivatives such as oxime) and bis (2,4,6-trimethyl) Benzoyl) - phosphine oxide compounds such as triphenylphosphine oxide. These photoinitiators may be used independently and 2 or more types may be used together. Of these, phosphine oxide-based initiators are preferable because the shape of the obtained liquid crystal alignment protrusions can be easily formed into an arch shape.

Examples of commercially available phosphine oxide initiators include Irgacure 819 (manufactured by Ciba Specialty Chemicals), Irgacure 819 (manufactured by Ciba Specialty Chemicals), Darocur TPO (manufactured by Ciba Specialty Chemicals), SP- 246 (made by ADEKA) etc. are mentioned.

In the negative resist of the present invention, the content of the photopolymerization initiator is not particularly limited, but the preferred lower limit is 0.1 parts by weight with respect to 100 parts by weight of the total of the alkali-soluble resin and the polymerizable monomer. A preferred upper limit is 40 parts by weight. When the content of the photopolymerization initiator is less than 0.1 parts by weight, the photocuring may be insufficient, and the adhesion of the liquid crystal alignment protrusions to the substrate may be reduced. The curing reaction may proceed excessively, resulting in a development residue, or the resulting liquid crystal alignment protrusions may not have an arch shape, which may cause abnormal liquid crystal alignment. The more preferable lower limit of the content of the photopolymerization initiator is 0.2 parts by weight, the more preferable upper limit is 30 parts by weight, the still more preferable lower limit is 0.5 parts by weight, and the still more preferable upper limit is 20 parts by weight.

The negative resist of the present invention may contain a reaction aid in order to reduce reaction disturbance due to oxygen. By using such a reaction aid and a hydrogen abstraction type photoreaction initiator in combination, the curing rate when irradiated with light can be improved.

Examples of the reaction aid include amine-based reaction aids such as n-butylamine, di-n-butylamine, triethylamine, triethylenetetramine, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, and tri-n. Examples include phosphine-based reaction aids such as -butylphosphine and sulfonic acid-based reaction aids such as s-benzylisothuronium-p-toluenesulfinate. These reaction aids may be used alone or in combination of two or more.

The negative resist of the present invention may contain a silane coupling agent.
The said silane coupling agent plays the role which improves the adhesiveness of the negative resist of this invention, and a board | substrate.
It does not specifically limit as said silane coupling agent, A conventionally well-known thing can be used. Especially, what has an acryloxy group or a methacryloxy group as a functional group is preferable. By containing a silane coupling agent having an acryloxy group or a methacryloxy group as a functional group, the adhesion of the negative resist of the present invention to the substrate can be greatly improved.

Examples of the silane coupling agent having an acryloxy group include 3-acryloxypropyltrimethoxysilane and 3-acryloxypropyltriethoxysilane.
Examples of the silane coupling agent having a methacryloxy group include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltri An ethoxysilane etc. are mentioned.
These silane coupling agents may be used independently and 2 or more types may be used together.

In the negative resist of the present invention, the content of the silane coupling agent is not particularly limited, but when the total of the alkali-soluble resin and the polymerizable monomer is 100 parts by weight, the preferred lower limit is 0.1 weight. Parts, and the preferred upper limit is 40 parts by weight. When the content of the silane coupling agent is less than 0.1 part by weight, the adhesion to the substrate may be lowered, and when it exceeds 40 parts by weight, an alkali development residue may occur in photolithography. The minimum with more preferable content of the said silane coupling agent is 1 weight part, and a more preferable upper limit is 30 weight part.

In the negative resist of the present invention, each component constituting the negative resist of the present invention described above uses an organic solvent, the lower limit of the solid content concentration is 5% by weight, the upper limit is 50% by weight, preferably the lower limit is 10% by weight. %, And adjusted so that the upper limit is in the range of 40% by weight.
The organic solvent is not particularly limited as long as it can dissolve or disperse the above-described components and is excellent in handleability. Specifically, for example, methyl cellosolve, ethyl cellosolve, butyl cellosolve, diethylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, propylene glycol monomethyl ether acetate (hereinafter abbreviated as “PGMAc”), methyl ethyl ketone, methyl isobutyl ketone, Examples include cyclohexanone, toluene, chloroform, dichloromethane, ethyl acetate, methyl lactate, ethyl lactate, methanol, ethanol, propanol, butanol, tetrahydrofuran and the like.
As said organic solvent, the range whose boiling point is 100-200 degreeC is used suitably, More preferably, the range whose boiling point is 120-180 degreeC is used.

The method for producing the negative resist of the present invention is not particularly limited. For example, the alkali-soluble resin, a polymerizable monomer containing a novolac epoxy (meth) acrylate, a photopolymerization initiator, an organic solvent, and an arbitrary solvent The method etc. which mix an additive with a stirring blade etc. in an agitating tank etc. are mentioned.

A method for producing a liquid crystal alignment protrusion using the negative resist of the present invention will be described.
In order to produce the liquid crystal alignment protrusions using the negative resist of the present invention, first, the negative resist of the present invention is applied on a substrate to have a predetermined thickness to form a coating.
The coating method is not particularly limited, and for example, conventionally known coating methods such as spin coating, slit & spin, slit coating, spray coating, dip coating, and bar coating can be used.

Next, actinic rays such as ultraviolet rays are irradiated on the formed film through a mask on which a predetermined pattern is formed. Thereby, in the light irradiation part, the alkali-soluble resin, the polymerizable monomer, and the photopolymerization initiator contained in the negative resist of the present invention are reacted and photocured.
The actinic light is not particularly limited and, for example, visible light, ultraviolet light, far ultraviolet light, electron beam, X-ray or the like can be used, but ultraviolet light is preferable.

The liquid crystal alignment protrusion can be formed, for example, by adjusting the amount of light applied to the liquid crystal alignment protrusion forming portion of the coating film. As a method for adjusting the irradiation amount, a conventionally used method may be used. For example, when irradiating actinic rays through the mask, an arch-shaped projection for liquid crystal alignment is performed by an alkali development process described later. For example, a method using a gray scale, a halftone mask, or the like can be used.

The wavelength of actinic rays such as ultraviolet rays to be irradiated is not particularly limited, but ultraviolet rays having a wavelength of about 200 to 600 nm are preferably used.
The preferable lower limit of the irradiation amount of the active light is 10 mJ / cm ² , and the preferable upper limit is 500 mJ / cm ² . When the irradiation amount of the actinic ray is less than 10 mJ / cm ² , the photocuring is insufficient, and a pattern may flow in the development process, resulting in poor adhesion. When the irradiation amount of the active light exceeds 500 mJ / cm ² , a development residue is likely to occur.

Next, the photocured product after photocuring is alkali-developed to form a liquid crystal alignment projection having a predetermined pattern made of the photocured product of the negative resist of the present invention on the substrate.
The solvent used in the alkali development treatment is not particularly limited as long as it is a solvent capable of dissolving the coating film of the uncured part. For example, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, sodium silicate An aqueous solution containing an inorganic alkali compound such as potassium silicate, sodium hydroxide or potassium hydroxide, or an organic alkali compound such as diethanolamine, triethylamine, triethanolamine, tetraalkylammonium hydroxide or tetramethylammonium hydroxide.

If necessary, the alkali developer may contain a surfactant, a water-soluble organic solvent, a wetting agent, a low molecular compound having a hydroxyl group or a carboxylic acid group, and the like. In particular, surfactants are preferably added because many surfactants have an improving effect on developability, resolution, background stains, and the like.

Examples of the surfactant used in the alkali developer include an anionic surfactant having a sodium naphthalenesulfonate group, a sodium benzenesulfonate group, a nonionic surfactant having a polyalkyleneoxy group, and a tetraalkylammonium group. And cationic surfactants having

Although it does not specifically limit as a method of an alkali image development process, Usually, it is carried out by methods, such as immersion development, spray development, brush development, ultrasonic development, at the development temperature of 10-50 degreeC, Preferably 15-45 degreeC.

Finally, it is thoroughly dried in a drying oven. The drying temperature is preferably 250 ° C. or less, and the drying time is preferably 60 minutes or less. If the temperature exceeds 250 ° C. and the drying time is longer than 60 minutes, when the liquid crystal alignment protrusion is formed on the color filter, the color pigment or dye in the opening is damaged and the display quality itself is deteriorated. There is a risk of letting you.

A projection for aligning liquid crystal using the negative resist of the present invention is also one aspect of the present invention.
The color filter having the liquid crystal alignment protrusion of the present invention is also one aspect of the present invention.

When the color filter of the present invention has a liquid crystal alignment protrusion made of the negative resist of the present invention described above, a liquid crystal display device using the color filter has a wide viewing angle.
The negative resist of the present invention or the liquid crystal display device using the color filter of the present invention is also one aspect of the present invention.

Note that columnar column spacers for regulating the cell gap of the liquid crystal display device can be formed using the negative resist of the present invention.
As a method of forming a column spacer using the negative resist of the present invention, for example, it is necessary to form, for example, a liquid crystal alignment protrusion on a portion to be a column spacer of a film formed on the substrate by the above-described method. The method of alkali development mentioned above after irradiating light more than exposure energy is mentioned. According to such a method, the negative resist of the present invention is sufficiently polymerized and cured by the light applied to the film, and a columnar column spacer higher than the liquid crystal alignment protrusion can be formed.

According to the present invention, a projection for controlling the liquid crystal alignment of a liquid crystal display device can be formed, and a negative resist for forming a projection for liquid crystal alignment that can prevent the occurrence of liquid crystal burn-in phenomenon in the manufactured liquid crystal display device. Can be provided.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
(1) Preparation of novolak epoxy (meth) acrylate 1000 parts by weight of phenol novolak type epoxy resin (Epiclon N-740, manufactured by Dainippon Ink & Chemicals), 2 parts by weight of p-methoxyphenol as a polymerization inhibitor, and triethylamine 2 as a reaction catalyst Part by weight and 200 parts by weight of acrylic acid were reacted for 5 hours while refluxing and stirring at 90 ° C. while feeding air. 100 parts by weight of the obtained resin was filtered through a column packed with 10 parts by weight of a natural combination of quartz and kaolin (manufactured by Hoffman Mineral Co., Ltd., Siritin V85) to adsorb ionic impurities in the reaction product. An acid-modified phenol novolac epoxy resin (50% partially acrylated, hydroxyl group content 50%) was obtained.

(2) Synthesis of alkali-soluble resin A stirrer, dropping funnel, condenser, thermometer, 150 parts by weight of PGMAc were placed in a flask equipped with a gas introduction tube, stirred while purging with nitrogen, and heated to 110 ° C.
Next, to a monomer mixture consisting of 32.6 parts by weight (0.38 mol) of methacrylic acid and 31.1 parts by weight (0.31 mol) of methyl methacrylate, t-butyl hydroperoxide (manufactured by NOF Corporation, Perbutyl O ) 3.6 parts by weight of the dropping funnel was dropped into the flask over 2 hours, and further stirred at 110 ° C. for 3 hours for aging.
Next, 36.4 parts by weight (0.20 mol) of 3,4-epoxycyclohexyl methacrylate, 0.36 parts by weight of triphenylphosphine and 0.15 parts by weight of methylhydroquinone were added, and the mixture was heated at 100 ° C. for 10 hours. Reacted. The reaction was carried out in an air / nitrogen atmosphere. As a result, an alkali-soluble resin solution P-1 (solid content 40%) having an acid value of 100 mgKOH / g, a double bond equivalent (g weight of resin per 1 mol of unsaturated groups) of 500, and a weight average molecular weight of 15000 was obtained.

(3) Preparation of projection-forming negative resist for liquid crystal alignment 200 parts by weight of the obtained alkali-soluble resin solution P-1, 100 parts by weight of a phenol novolac epoxy acrylate dispersion obtained as a heavy monomer, photoreaction 10 parts by weight of Irgacure 819 (manufactured by Ciba Specialty Chemicals, acylphosphine oxide) as an initiator and 200 parts by weight of PGMAc as a solvent were mixed to prepare a negative resist for forming a liquid crystal alignment protrusion.

(4) Production of color filter A Cr thin film pattern was formed on a transparent substrate by a photoetching method. A red, blue, and green photosensitive resin composition was patterned thereon by photolithography to form red, blue, and green pixels. Further, an ITO film was formed on the entire surface by sputtering to form a transparent conductive film layer, and a color filter was manufactured.

(5) Manufacture of a color filter substrate on which liquid crystal alignment protrusions are formed The obtained negative resist for forming liquid crystal alignment protrusions is spin-coated on the color filter manufactured in (4) and then dried at 80 ° C. for 2 minutes. To obtain a coating film. The obtained coating film was irradiated with 100 mJ / cm ² ultraviolet rays through an 8 μm square dot pattern mask, developed with a 0.1% aqueous sodium carbonate solution for 60 seconds, and washed with pure water for 30 seconds. Thereafter, a baking process at 200 ° C. for 30 minutes was performed to obtain a color filter substrate having alignment control protrusions.

(Example 2)
By the method according to Example 1, a phenol novolak epoxy acrylate dispersion (solid content: 80% by weight) having a hydroxyl group content of about 15 mol% was obtained.
A negative resist for forming a liquid crystal alignment protrusion was prepared in the same manner as in Example 1 except that the obtained phenol novolak epoxy acrylate having a hydroxyl group amount of about 30 mol% was used. A color filter substrate was obtained.

(Example 3)
By the method according to Example 1, a phenol novolak epoxy acrylate dispersion (solid content 80% by weight) having a hydroxyl group content of about 30 mol% was obtained.
A negative resist for forming a liquid crystal alignment protrusion was prepared in the same manner as in Example 1 except that the obtained phenol novolak epoxy acrylate having a hydroxyl group amount of about 30 mol% was used. A color filter substrate was obtained.

Example 4
By the method according to Example 1, a phenol novolac epoxy acrylate dispersion (solid content: 80% by weight) having a hydroxyl group content of about 70 mol% was obtained.
A negative resist for forming a liquid crystal alignment protrusion was prepared in the same manner as in Example 1 except that the obtained phenol novolak epoxy acrylate having a hydroxyl group amount of about 30 mol% was used. A color filter substrate was obtained.

(Comparative Example 1)
By the method according to Example 1, a phenol novolak epoxy acrylate dispersion having a hydroxyl group content of 0 mol% (solid content: 80% by weight) was obtained.
A negative resist for forming a liquid crystal alignment protrusion was prepared in the same manner as in Example 1 except that the obtained phenol novolak epoxy acrylate having a hydroxyl group amount of about 30 mol% was used. A color filter substrate was obtained.

(Comparative Example 2)
By the method according to Example 1, a phenol novolak epoxy acrylate dispersion (solid content: 80% by weight) having a hydroxyl group content of about 5 mol% was obtained.
A negative resist for forming a liquid crystal alignment protrusion was prepared in the same manner as in Example 1 except that the obtained phenol novolak epoxy acrylate having a hydroxyl group amount of about 30 mol% was used. A color filter substrate was obtained.

(Comparative Example 3)
By the method according to Example 1, a phenol novolak epoxy acrylate dispersion (solid content 80% by weight) having a hydroxyl group content of about 90 mol% was obtained.
A negative resist for forming a liquid crystal alignment protrusion was prepared in the same manner as in Example 1 except that the obtained phenol novolak epoxy acrylate having a hydroxyl group amount of about 30 mol% was used. A color filter substrate was obtained.

(Comparative Example 4)
Projections for aligning liquid crystal in the same manner as in Example 1 except that 1,4-butanediol diglycidyl ether diacrylate (Aronix M450, manufactured by Toagosei Co., Ltd.) was used instead of phenol novolac epoxy acrylate (EA-6320). A negative resist for formation was prepared, and a color filter substrate having liquid crystal alignment protrusions was obtained using the resist.

(Comparative Example 5)
Instead of phenol novolac epoxy acrylate (EA-6320), except that pentaerythritol triacrylate (PE-3A, manufactured by Kyoeisha) was used, a negative resist for forming liquid crystal alignment protrusions was prepared in the same manner as in Example 1, Using this, a color filter substrate having a liquid crystal alignment protrusion was obtained.

(Evaluation)
The following evaluation was performed about the color filter substrate which has the processus | protrusion for liquid crystal alignment obtained in Examples 1-4 and Comparative Examples 1-5.
The results are shown in Table 1.

(1) Evaluation of burn-in Using the obtained color filter substrate having the liquid crystal alignment protrusions, an MVA-LCD was produced. Thereafter, a voltage was continuously applied to the MVA-LCD for 24 hours at room temperature to perform image display. The image after 24 hours of continuous display was visually observed. The case where the display pattern immediately disappeared was evaluated as “◎”, the case where the display pattern disappeared within 1 minute was evaluated as “◯”, and the case where the display pattern did not disappear within 1 minute was evaluated as “×”.

(2) Evaluation of protrusion shape The liquid crystal alignment protrusions formed on the color filter substrate were observed using a microscope. As for the protrusion shape, “◎” when it is an arch shape, “◯” when it is an arch shape that is a little trapezoidal, “△” when it is a trapezoid shape, and “×” when it is a column shape. It was evaluated.

According to the present invention, a projection for controlling the liquid crystal alignment of a liquid crystal display device can be formed, and a negative resist for forming a projection for liquid crystal alignment that can prevent the occurrence of liquid crystal burn-in phenomenon in the manufactured liquid crystal display device. Can be provided.

Claims (5)

A negative resist used for forming projections for liquid crystal alignment of an MVA liquid crystal display device, comprising an alkali-soluble resin, a polymerizable monomer, and a photopolymerization initiator,
The negative resist for forming a protrusion for liquid crystal alignment, wherein the polymerizable monomer contains a novolac epoxy (meth) acrylate having a hydroxyl amount of 15 to 70 mol%. 2. The negative resist for forming a protrusion for liquid crystal alignment according to claim 1, wherein the novolak epoxy (meth) acrylate has a weight average molecular weight of 800 to 2,000. The negative resist for forming a projection for liquid crystal alignment according to claim 1 or 2, wherein the novolak epoxy (meth) acrylate has an alkali-soluble functional group. 4. The negative resist for forming a projection for liquid crystal alignment according to claim 1, wherein the alkali-soluble resin has a (meth) acryl group, a carboxyl group, and a benzyl group. 5. The negative resist for forming a protrusion for liquid crystal alignment according to claim 1, wherein the photopolymerizable initiator contains a phosphine oxide-based initiator.