JP5374903B2 - Negative resist composition for color filter, color filter, and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a negative resist composition for a color filter, the composition excellent in pigment dispersibility and alkali developability. <P>SOLUTION: The composition contains a pigment dispersant, a pigment, an alkali-soluble resin, a polyfunctional monomer, a photo initiator and the like, wherein the pigment dispersant is a block copolymer having a structural unit (1) expressed by formula (I) and a structural unit (2) having a (meth)acrylate structure, in which an amino group of the structural unit (1) and a sulfonic acid compound such as an acidic sulfate form a salt. In formula (I), R<SP>1</SP>represents a hydrogen atom or a methyl group; each of R<SP>2</SP>and R<SP>3</SP>independently represents a hydrogen atom or a 1-8C alkyl group; A represents a 1-8C alkylene group or the like; and m represents an integer of from 1 to 200. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a negative resist composition for color filters, a color filter, and a liquid crystal display device. More specifically, the present invention is a negative resist composition for color filters having excellent pigment dispersibility and excellent alkali developability, a color filter formed using the resist composition, and a liquid crystal display device having the color filter It is about.

  In recent years, with the development of personal computers, particularly portable personal computers, the demand for liquid crystal displays has increased. In recent years, the penetration rate of home-use liquid crystal televisions has been increasing, and the market for liquid crystal displays is expanding. Furthermore, liquid crystal displays that have become widespread in recent years tend to have larger screens, and this tendency is particularly strong for home-use liquid crystal televisions. In such a situation, it is desired to manufacture a high-quality low-cost and high-quality member that constitutes the liquid crystal display, particularly in a color filter having a function of color-displaying the liquid crystal display. However, such demands are increasing because of its high cost.

  Here, as a general method for producing a color filter, a coating film made of a photocurable resist composition in which a pigment of each color is dispersed is formed on a substrate on which a light shielding portion is formed in a pattern, and a desired color filter is formed. A method is used in which a colored layer of each color is formed in a pattern by exposure and alkali development through a photomask having a pattern.

  As the photocurable resist composition used for the production of such a color filter, in addition to the above-mentioned pigments of the respective colors, a pigment dispersant, an alkali-soluble resin, and a multi-component added to uniformly disperse the pigment are usually used. Those having a functional monomer, a photoinitiator, and a solvent are used. As a pigment dispersant used in such a photocurable resist composition, if the dispersibility of the pigment is insufficient when forming a colored layer of a color filter, color unevenness may occur in the colored layer. Therefore, those having excellent dispersibility are used. As a photocurable resist composition in which such a pigment dispersant having excellent dispersibility is used, an A block having a quaternary ammonium base in the side chain as a pigment dispersant and a B having no quaternary ammonium base are used. A composition for a color filter using an A-B block copolymer and / or a B-A-B block copolymer comprising blocks is disclosed (for example, see Patent Document 1).

In recent years, there has been an increasing demand for high contrast in liquid crystal display devices, and in order to achieve such a demand, finer pigments are required. Therefore, the surface area of the pigment in the photo-curable resist composition is increased, and it is necessary to increase the amount of the pigment dispersant that is necessary for uniformly dispersing the pigment.
However, in the conventional pigment dispersant containing a quaternary ammonium base as disclosed in Patent Document 1, it is possible to ensure uniform dispersibility of the pigment by increasing the amount of addition, but alkali developability There is a problem that the time required for alkali development is prolonged, and that the unexposed photocurable resist composition remains on the substrate, resulting in a decrease in productivity and quality.

JP 2002-31713 A

  The present invention has been made under such circumstances, a negative resist composition for color filters having excellent pigment dispersibility and excellent alkali developability, a color filter formed using the resist composition, and It is an object of the present invention to provide a liquid crystal display device having this color filter.

As a result of intensive studies to achieve the above object, the inventors of the present invention include a pigment dispersant, a pigment, an alkali-soluble resin, a polyfunctional monomer, a photoinitiator, and a solvent, and As the pigment dispersant, a resist composition using an acidic sulfate ester salt and / or sulfonate salt of a block copolymer having a specific structure is excellent in pigment dispersibility and excellent in alkali developability. It was found that it can be adapted.
The present invention has been completed based on such findings.

That is, the present invention
(1) A color having (A) a pigment dispersant, (B) a pigment, (C) an alkali-soluble resin, (D) a polyfunctional monomer, (E) a photoinitiator, and (F) a solvent. A negative resist composition for a filter, wherein the (A) pigment dispersant is a structural unit (1) represented by the following general formula (I) and a structural unit represented by the following general formula (II) ( 2), and further the amino group of the structural unit (1), the acidic sulfate represented by the following general formula (III) and / or the sulfonic acid compound represented by the following general formula (IV) A negative resist composition for color filters, characterized in that is a block copolymer in which a salt is formed,

[In formulas (I) to (IV), R ¹ is a hydrogen atom or a methyl group, R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and A is a carbon atom having 1 to 8 carbon atoms. An alkylene group, — [CH (R ⁶ ) —CH (R ⁷ ) —O] _x —CH (R ⁶ ) —CH (R ⁷ ) — or [(CH ₂ ) _y —O] _z — (CH ₂ ) _y A divalent group represented by-, R ⁴ is an alkyl group having 1 to 18 carbon atoms, benzyl group, phenyl group, pyridyl group, biphenyl group, pyridylphenyl group,-[CH (R ⁶ ) -CH (R ⁷ ) —O] _x —R ⁸ or — [(CH ₂ ) _y —O] _z —R ⁸ , wherein R ⁵ and R ⁵ ′ have a polymerizable group, each independently having 2 carbon atoms -18 alkenyl groups,-[CH (R ⁹ ) -CH (R ¹⁰ ) -O] _a -R ¹¹ or-[(CH ₂ ) _{b -O]} shows the c ^{-R 11.}
R ⁶ , R ⁷ , R ⁹ and R ¹⁰ are each independently a hydrogen atom or a methyl group, R ⁸ is a hydrogen atom, or an alkyl group having 1 to 18 carbon atoms, a benzyl group, a phenyl group, a pyridyl group, a biphenyl group, A pyridylphenyl group, —CHO, —CH ₂ CHO, —COCH═CH ₂ , —CO—C (CH ₃ ) ═CH ₂ or a monovalent group represented by —CH ₂ COOR ¹² , R ¹¹ is —COCH ═CH ₂ , or a monovalent group represented by —CO—C (CH ₃ ) ═CH ₂ , and R ¹² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
x and a are integers of 0 to 18, y and b are integers of 1 to 5, z and c are integers of 0 to 18, and m and n are integers of 1 to 200, respectively. ]
(2 ) The negative resist composition for a color filter according to the above ( 1 ), wherein the polymerizable group is a vinyl group ,
( 3 ) The negative resist composition for color filters according to (1) or (2) above, wherein the average particle size of the (B) pigment is 10 to 100 nm,
( 4 ) (D) The negative resist composition for color filters according to any one of (1) to ( 3 ), wherein the polyfunctional monomer is a compound having two or more ethylenically unsaturated bonds,
( 5 ) The negative resist composition for color filters according to ( 4 ) above, wherein the compound having two or more ethylenically unsaturated bonds is a polyfunctional (meth) acrylate,
( 6 ) A color filter comprising a colored layer formed using the negative resist composition for a color filter according to any one of (1) to ( 5 ), and ( 7 ) the above ( A liquid crystal display device comprising the color filter according to 6 ),
Is to provide.

  According to the present invention, a negative resist composition for a color filter having excellent pigment dispersibility and excellent alkali developability, a color filter formed using the resist composition, and a liquid crystal display device having the color filter are provided. can do.

First, the negative resist composition for color filters of the present invention will be described.
[Negative resist composition for color filter]
The negative resist composition for color filters of the present invention (hereinafter sometimes simply referred to as a negative resist composition) comprises (A) a pigment dispersant, (B) a pigment, (C) an alkali-soluble resin, (D) a polyfunctional monomer, (E) a photoinitiator, and (F) a solvent, wherein the (A) pigment dispersant has the following properties.

((A) Pigment dispersant)
In the negative resist composition of the present invention, the pigment dispersant used as the component (A) includes a structural unit (1) represented by the following general formula (I) and a structure represented by the following general formula (II). An amino group of the structural unit (1), an acidic sulfate ester represented by the following general formula (III) and / or a sulfonic acid represented by the following general formula (IV): A block copolymer in which a compound forms a salt (hereinafter sometimes referred to as a salt-type block copolymer).

[In the formulas (I) to (IV), R ¹ is a hydrogen atom or a methyl group, R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and A is a carbon atom having 1 to 8 carbon atoms. An alkylene group, — [CH (R ⁶ ) —CH (R ⁷ ) —O] _x —CH (R ⁶ ) —CH (R ⁷ ) — or — [(CH ₂ ) _y —O] _z — (CH ₂ ) _y - 2 divalent group, R ⁴ represented by an alkyl group having 1 to 18 carbon atoms, a benzyl group, a phenyl group, a pyridyl group, a biphenyl group, pyridyl phenyl ^{group, - [CH (R 6)} -CH (R ⁷ ) —O] _x —R ⁸ or — [(CH ₂ ) _y —O] _z —R ⁸ , wherein R ⁵ and R ^{5 ′} are each independently an alkyl group having 1 to 18 carbon atoms or 2 carbon atoms. to 18 alkenyl group, a benzyl group, a phenyl group, a pyridyl group, a biphenyl group, pyridyl phenyl ^{group, - [CH (R 9)} -CH (R 10) -O] _a -R ¹¹ or - indicates a _{[(CH 2) b -O]} c -R 11.
R ⁶ , R ⁷ , R ⁹ and R ¹⁰ are each independently a hydrogen atom or a methyl group, R ⁸ and R ¹¹ are each independently a hydrogen atom, or an alkyl group having 1 to 18 carbon atoms, a benzyl group, a phenyl group, a pyridyl group, a biphenyl group, pyridyl phenyl _{group, -CHO, -CH 2 CHO, -CO} -CH = CH 2, -CO-C (CH 3) = CH 2 , or a monovalent group represented by -CH ₂ COOR ¹² R ¹² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
x and a are integers of 0 to 18, y and b are integers of 1 to 5, z and c are integers of 0 to 18, and m and n are integers of 1 to 200, respectively. ]

According to this invention, it has the structural unit (1) represented by the general formula (I) and the structural unit (2) represented by the general formula (II), and the structural unit (1). A salt type block copolymer in which the amino group possessed by the acid group and the acidic sulfate ester represented by the general formula (III) and / or the sulfonic acid compound represented by the following general formula (IV) form a salt. By strengthening the adhesion of the structural unit (1) that forms the salt-forming site to the pigment (B), and the structural unit (2) is soluble in the (F) solvent, (B) The pigment can be stabilized, and as a result, the dispersibility and stability of the (B) pigment can be improved.
In addition, by having an acidic sulfate ester represented by the general formula (III) and / or a sulfonic acid compound represented by the following general formula (IV), the amino group contained in the structural unit (1) and the acidic group Since the salt-forming site formed by the sulfate ester and / or the sulfonic acid compound has high solubility in an alkaline aqueous solution during alkali development, it can be made excellent in alkali developability. Therefore, when a color filter is produced using the negative resist composition for a color filter of the present invention, the alkali development time can be shortened and the productivity can be improved. Moreover, by being excellent in alkali developability, it is possible to obtain a high-quality color filter with little residue of the negative resist composition for color filter in an unexposed area.

<Block copolymer>
The block copolymer in the pigment dispersant comprising the salt type block copolymer is composed of the structural unit (1) represented by the general formula (I) and the structural unit (2 represented by the general formula (II)). ).
In the general formula (I), R ¹ represents a hydrogen atom or a methyl group, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Here, the alkyl group having 1 to 8 carbon atoms may be linear, branched or cyclic. Examples of such alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, various pentyl groups, various hexyl groups, and various octyl groups. Group, cyclopentyl group, cyclohexyl group, cyclooctyl group and the like. Among these, a methyl group and an ethyl group are preferable.
In the present invention, R ² and R ³ may be the same or different.

A represents an alkylene group having 1 to 8 carbon atoms, — [CH (R ⁶ ) —CH (R ⁷ ) —O] _x —CH (R ⁶ ) —CH (R ⁷ ) — or [(CH ₂ ) _y —. O] _z— (CH ₂ ) _y — is a divalent group. Here, the alkylene group having 1 to 8 carbon atoms may be linear or branched. For example, a methylene group, an ethylene group, a trimethylene group, a propylene group, various butylene groups, various pentylene groups, various types. A hexylene group, various octylene groups, and the like.
R ⁶ and R ⁷ are each independently a hydrogen atom or a methyl group.
x is an integer of 0 to 18, preferably an integer of 0 to 4, more preferably an integer of 0 to 2, and y is an integer of 1 to 5, preferably an integer of 1 to 4, more preferably 2 or 3. is there. z is an integer of 0-4, preferably an integer of 0-2. In the present invention, when x, y and z are in the above ranges, the negative resist composition for color filter of the present invention has excellent pigment dispersibility.
As this A, a C1-C8 alkylene group is preferable, and a methylene group and ethylene group are more preferable. If the carbon number is in the range of 1 to 8, the dispersibility of the pigment can be kept good.

In the general formula (II), R ⁴ represents an alkyl group having 1 to 18 carbon atoms, a benzyl group, a phenyl group, a pyridyl group, a biphenyl group, a pyridylphenyl group, — [CH (R ⁶ ) —CH (R ⁷ ). —O] _x —R ⁸ or — [(CH ₂ ) _y —O] _z —R ⁸ is shown. In the case where R ⁴ is an aromatic ring, the aromatic ring suitable substituents on, for example, C1-4 linear, may have such branched alkyl groups.
The alkyl group having 1 to 18 carbon atoms may be linear, branched, or cyclic. For example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, sec-butyl group, tert-butyl group, various pentyl groups, various hexyl groups, various octyl groups, various decyl groups, various dodecyl groups, various tetradecyl groups, various hexadecyl groups, various octadecyl groups, cyclopentyl groups, cyclohexyl groups, cyclooctyl Group, cyclododecyl group, bornyl group, isobornyl group, dicyclopentanyl group, adamantyl group, lower alkyl group-substituted adamantyl group and the like.

R ⁶ and R ⁷ are the same as described above, and R ⁸ is a hydrogen atom or an optionally substituted alkyl group having 1 to 18 carbon atoms, benzyl group, phenyl group, pyridyl group, biphenyl group. , A pyridylphenyl group, —CHO, —CH ₂ CHO, —CO—CH═CH ₂ , —CO—C (CH ₃ ) ═CH ₂ or —CH ₂ COOR ¹² , R ¹² Is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 5 carbon atoms.
R ⁸ may have a substituent, and examples of the substituent include a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms, a halogen atom such as F, Cl, and Br. Can be mentioned.
The alkyl group having 1 to 18 carbon atoms in R ⁸ is as shown in R ⁴ above.
In R ⁴ , x, y and z are as described in A above.

In the present invention, as R ⁴ , it is preferable to use those having excellent solubility with the solvent described later, and specifically, it varies depending on the structural unit constituting the block copolymer. In the case where the solvent is tetrahydrofuran, toluene or the like, it is preferable to use a methyl group, an ethyl group, a benzyl group or the like, and in the case where the solvent is a less polar one such as pentane or hexane, It is preferable to use a pentyl group, hexyl group, heptyl group or the like.
The reason for setting the R ⁴ in this way, the structural unit comprising the R ⁴ (2) has a solubility in the solvent, and the amino group of the constituent unit (1), which will be described later acidic sulfate Because the salt-forming site formed by the ester and / or sulfonic acid compound has high adsorptivity to the pigment, the dispersibility and stability of the pigment can be made particularly excellent. is there.
Further, R ⁴ is substituted with a substituent such as an alkoxy group, a hydroxyl group, a carboxyl group, an amino group, an epoxy group, or a hydrogen bond-forming group as long as it does not interfere with the dispersion performance of the block copolymer. Also good.

  The ratio m / n of the number of units m of the structural unit (1) and the number of units n of the structural unit (2) used in the present invention is preferably within the range of 0.01 to 1, preferably 0.05 to More preferably, it is in the range of 0.5. If the ratio m / n is within the above range, the ratio of the salt-forming site formed by the amino group of the structural unit (1) is appropriate, so that the adsorptivity to the pigment described later is good, and the structural unit ( The solubility with the above solvent according to 2) does not decrease, and the dispersibility and stability of the pigment do not decrease.

In the block copolymer used in the present invention, the number of units m of the structural unit (1) and the number of units n of the structural unit (2) may be integers of 1 to 200, respectively, and are not particularly limited. m is preferably in the range of 1 to 20, and more preferably in the range of 1 to 10. Moreover, as said n, it is preferable to exist in the range of 20-100.
Furthermore, the weight average molecular weight Mw of the block copolymer is preferably in the range of 500 to 20000, more preferably in the range of 1000 to 15000, and still more preferably in the range of 3000 to 12000. . By being in the above range, the pigment can be uniformly dispersed.

  The weight average molecular weight Mw is a value measured by GPC (gel permeation chromatography). For the measurement, HLC-8120GPC manufactured by Tosoh Corporation was used, the elution solvent was N-methylpyrrolidone to which 0.01 mol / liter of lithium bromide was added, and the polystyrene standard for calibration curve was Mw377400, 210500, 96000, 50400. , 206500, 10850, 5460, 2930, 1300, 580 (Easi PS-2 series manufactured by Polymer Laboratories) and Mw1090000 (manufactured by Tosoh Corporation), and TSK-GEL ALPHA-M × 2 (Tosoh Corporation) (Made by Co., Ltd.)

  The binding order of the block copolymer used in the present invention is not particularly limited as long as it has the structural unit (1) and the structural unit (2) and can stably disperse a pigment described later. Although not limited, it is preferable that the structural unit (1) is bonded to only one end of the block copolymer. That is, the structural unit (1) and the structural unit (2) may be combined in the order of the structural unit (1) -the structural unit (2), or the structural unit (1) -the structural unit. (2) -the structural unit (1) may be combined in this order, the structural unit (2) -the structural unit (1) -the structural unit (2) may be combined in this order, The structural unit (1) -structural unit (2) may be repeatedly bonded, but in the present invention, the structural unit (1) -structural unit (2) are preferably combined in this order. The reason is that it is excellent in the adsorptivity with respect to the pigment mentioned later, and also the aggregation of pigment dispersants using such a block copolymer can be effectively suppressed.

<Acidic sulfate and sulfonic acid compound>
An amino group contained in the structural unit (1) of the block copolymer having the structural unit (1) represented by the general formula (I) and the structural unit (2) represented by the general formula (II); The acidic sulfate ester and sulfonic acid compound forming a salt are compounds having structures represented by the general formula (III) and the general formula (IV), respectively.
In the present invention, by using the acidic sulfate ester and / or sulfonic acid compound, the pigment dispersant can be made excellent in the dispersibility and stability of the pigment described later, and the salt-forming site is further provided. Since it has high solubility in an aqueous alkali solution during alkali development, it can be excellent in alkali developability.

In the above general formula (III) and general formula (IV), R ⁵ and R ^{5 ′} are each independently an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a benzyl group, a phenyl group, or pyridyl. shows a _{[(CH 2) b -O]} c -R 11 - group, biphenyl group, pyridyl phenyl ^{group, - [CH (R 9)} -CH (R 10) -O] a -R 11 or. In the case where R ⁵ and R ^{5 'has} an aromatic ring, the aromatic ring suitable substituents on, for example, C1-4 linear, may have such branched alkyl groups.
The said C1-C18 alkyl group is as having shown by said R < ⁴ >.
The alkenyl group having 1 to 18 carbon atoms may be linear, branched or cyclic. Examples of such alkenyl groups include vinyl groups, allyl groups, propenyl groups, various butenyl groups, various hexenyl groups, various octenyl groups, various decenyl groups, various dodecenyl groups, various tetradecenyl groups, various hexadecenyl groups, various octadecenyl groups, A cyclopentenyl group, a cyclohexenyl group, a cyclooctenyl group, etc. can be mentioned.

R ⁹ and R ¹⁰ each independently represent a hydrogen atom or a methyl group. R ¹¹ is a hydrogen atom or an optionally substituted alkyl group having 1 to 18 carbon atoms, benzyl group, phenyl group, pyridyl group, biphenyl group, pyridylphenyl group, —CHO, —CH ₂ CHO, — CO—CH═CH ₂ , —CO—C (CH ₃ ) ═CH ₂ or a monovalent group represented by —CH ₂ COOR ¹² , R ¹² is a hydrogen atom or a straight chain having 1 to 5 carbon atoms, A branched or cyclic alkyl group.
In the monovalent group represented by R ¹¹ , examples of the substituent that may be included include linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms, and halogen atoms such as F, Cl, and Br. And so on.
The alkyl group having 1 to 18 carbon atoms in R ¹¹ is as described above for R ⁵ and R ^{5 ′} .
In the R ⁵ and R ^{5 ',} a is an integer of 0 to 18, b is an integer of from 1 to 5, c is an integer of 0 to 18.

As the acidic sulfate ester represented by the general formula (III) and the sulfonic acid compound represented by the general formula (IV), R ⁵ and R ^{5 ′} are each independently a methyl group, an isopropyl group, or an n-butyl group. , 2-ethylhexyl group, a vinyl group, an allyl group or a ^{- (CH (R 9) -CH} (R 10) -O) a -R 11 or _{- ((CH 2) b -O} ) a _c -R ^11, R ¹¹ is preferably —CO—CH═CH ₂ or —CO—C (CH ₃ ) ═CH _2. Among them, those having a polymerizable group, that is, vinyl group, allyl group or — (CH ( ^{R 9) -CH (R 10)} -O) a -R 11 or _{- ((CH 2) b -O} ) a _c -R ^11, and R ¹¹ is -CO-CH = CH ₂ or -CO-C (CH ₃₎ = are preferable is CH _2, in particular R ⁵ and R ^{5 'are} each independently a vinyl group, Lil group, 2-methacryloyloxyethyl group, it is preferable 2-acryloyloxy ethyl group.

R ⁵ in the acidic sulfate ester or R ^{5 ′} in the sulfonic acid compound is a methyl group, isopropyl group, n-butyl group, 2-ethylhexyl group, vinyl group, allyl group, or — (CH (R ⁹ ) —CH (R). ¹⁰⁾ -O) _a -R ¹¹ or _{- ((CH 2) b -O} ) a _c -R ^11, and R ¹¹ is -CO-CH = CH ₂ or _{-CO-C (CH 3) =} CH 2 Therefore, the acidic sulfuric acid ester and the sulfonic acid compound can be excellent in pigment dispersibility and alkali developability. R ⁵ and R ^{5 ′} are vinyl group, allyl group, or — (CH (R ⁹ ) —CH (R ¹⁰ ) —O) _a —R ¹¹ or — ((CH ₂ ) _b —O) _c —R ¹¹ And when R ¹¹ is —CO—CH═CH ₂ or —CO—C (CH ₃ ) ═CH ₂ , the acidic sulfuric acid ester and the sulfonic acid compound contain a polymerizable group. Therefore, at the time of exposure when forming a colored layer using the negative resist composition for a color filter of the present invention, the polymerizable groups and / or the polymerizable group and the negative resist composition for a color filter of the present invention. The alkali-soluble resin and the polyfunctional monomer contained in the product can be easily polymerized, and the pigment dispersant can be stably present in the colored layer of the color filter. Therefore, when a liquid crystal display device is manufactured using such a color filter, the pigment dispersant can be prevented from bleeding out to the liquid crystal layer or the like.

  In addition, since the acidic sulfate ester and the sulfonic acid compound contain a polymerizable group, the polymerizable sulfuric acid ester and the sulfonic acid compound can be polymerized with each other before being used for forming the colored layer. As a result, since the pigment dispersant has a high molecular weight, the negative resist composition for the color filter in the unexposed portion can be made particularly excellent in alkali developability at the time of developing the colored layer.

Here, the reason why the polymerizable groups are particularly excellent in alkali developability due to polymerization is presumed as follows.
That is, all of the added pigment dispersant does not contribute to the improvement of the dispersibility of the pigment described later, but a part of the pigment dispersant is present in a free state from the pigment. In addition, since the pigment dispersant generally lowers alkali developability, when there is a large amount of the pigment dispersant in a free state, it inhibits alkali development at the time of developing a colored layer. become.
On the other hand, the polymerizable groups are polymerized before being used for forming the colored layer, and have a high molecular weight, so that in the development of the colored layer, free pigment dispersion in the negative resist composition for the color filter. The amount of the agent can be reduced. For this reason, the inhibition of alkali development by the free pigment dispersant can be reduced, and the negative resist composition for color filter in the unexposed area can be made particularly excellent in alkali developability.

The content of the acidic sulfate ester and / or sulfonic acid compound in the pigment dispersant (A) used in the present invention is not particularly limited as long as good pigment dispersion stability is exhibited. About 0.1-4.0 mol% with respect to the amino group contained in the unit (1), preferably 0.2-2.0 mol%, more preferably 0.5-1.0 mol%. . In addition, when using together acidic sulfuric ester and a sulfonic acid compound, content which totaled these should just be in the said range.
In the negative resist composition for a color filter of the present invention, as described above, as the pigment dispersant of the component (A), the structural unit (1) represented by the general formula (I) and the general formula (II) are used. The structural unit (2) and the amino group of the structural unit (1), the acidic sulfate represented by the general formula (III) and / or the general formula (IV) A salt type block copolymer formed by forming a salt with a sulfonic acid compound is used.
By using such a salt type block copolymer as a pigment dispersant, the negative resist composition for color filters of the present invention can be made excellent in pigment dispersion stability.

<Production of salt type block copolymer>
In the present invention, the production method of the salt-type block copolymer used as the pigment dispersant of the component (A) includes the structural unit (1) and the structural unit (2), and the structural unit (1 ) And an acid sulfate ester represented by the general formula (III) and / or a sulfonic acid compound represented by the general formula (IV) can form a salt. There is no particular limitation as long as it is. In the present invention, for example, the structural unit (1) and the structural unit (2) are polymerized using a known polymerization means, and then dissolved or dispersed in a solvent described later, and then the acidic sulfuric acid is dissolved in the solvent. It can manufacture by adding ester and / or a sulfonic acid compound, and stirring.
The polymerization means is not particularly limited as long as it is a means capable of polymerizing the structural unit (1) and the structural unit (2) at a desired unit ratio to obtain a desired molecular weight. A method generally used for polymerization of the compound having the above can be employed, and for example, anionic polymerization, living radical polymerization, or the like can be used. In the present invention, among them, a method in which polymerization proceeds in a living manner, such as group transfer polymerization (GTP) disclosed in “J. Am. Chem. Soc.” 105, 5706 (1983), is used. preferable. According to this method, it is easy to make the molecular weight, molecular weight distribution, and the like within a desired range, so that the properties such as dispersibility and alkali developability of the pigment dispersant can be made uniform.

  In the negative resist composition for a color filter of the present invention, as the pigment dispersant as the component (A), one type of the above-mentioned salt type block copolymer may be used, or two or more types may be used in combination. The content is appropriately selected according to the type of pigment used, the solid content concentration in the negative resist composition, and the like, but is usually 5 to 200 parts by mass with respect to 100 parts by mass of the pigment described later. It is a range, It is preferable that it is 10-100 mass parts, and it is more preferable that it is 20-80 mass parts. If the content of the salt-type block copolymer is within the above range, the pigment can be uniformly dispersed, and the blending ratio of the alkali-soluble resin and the polyfunctional monomer is not relatively lowered and sufficient. A colored layer having hardness can be formed.

((B) Pigment)
In the negative resist composition for a color filter of the present invention, the pigment used as the component (B) is not particularly limited as long as it can produce a desired color when a colored layer of the color filter is formed. Various organic or inorganic colorants can be used alone or in admixture of two or more.
<Type of pigment>
As the organic colorant, for example, dyes, organic pigments, natural pigments, and the like can be used. Specific examples of the organic pigment include compounds classified as “Pigment” in the color index (CI; issued by The Society of Dyers and Colorists).
Examples of such compounds include C.I. I. Pigment yellow 1, C.I. I. Pigment yellow 3, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 139, C.I. I. Pigment yellow 150, C.I. I. Pigment yellow 180, C.I. I. Yellow pigments such as C.I. Pigment Yellow 185; I. Pigment red 1, C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 242, C.I. I. Pigment red 254, C.I. I. Red pigments such as C.I. Pigment Red 177; I. Pigment blue 15, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. C.I. Blue pigments such as CI Pigment Blue 15: 6; I. Pigment Violet 23 such as Pigment Violet 23; and Pigment Green 36, C.I. I. And pigments having a color index (C.I.) number such as CI pigment green 58.

  Further, as the inorganic colorant, for example, inorganic pigments, extender pigments and the like can be used. Specific examples include titanium oxide, silica, barium sulfate, calcium carbonate, zinc white, lead sulfate, yellow lead, zinc yellow, Bengala (red iron oxide (III)), cadmium red, ultramarine blue, bitumen, chromium oxide green, cobalt green, amber, titanium black, synthetic iron black, carbon black and the like can be mentioned.

<Particle particle size>
The average particle diameter of the pigment used in the present invention is not particularly limited as long as it can produce a desired color when it is used as a colored layer of a color filter, and varies depending on the type of pigment used. It is preferably in the range of ˜100 nm, and more preferably in the range of 10 to 50 nm. When the average particle diameter of the pigment is in the above range, the liquid crystal display device manufactured using the negative resist composition for color filter of the present invention has high contrast and high quality, and at low cost. Can be produced. In addition, with conventional pigment dispersants, as the particle size of the pigment becomes smaller, a large amount of pigment dispersant is required, which may cause problems such as reduced alkali developability and increased residue. Since the pigment dispersant used in the negative resist composition for color filters is excellent in alkali developability, it is less likely to cause such a problem. Therefore, as the average particle size of the pigment is within the above range, the smaller the conventional particle size is, the more the characteristics of the negative resist composition for color filters of the present invention can be exhibited.
The average particle diameter is a value measured by a laser scattering method. Specifically, the average particle diameter is measured by dispersing pigment particles in a solvent, capturing the scattered light obtained by irradiating the dispersion solvent with a laser beam, and calculating.

In the negative resist composition for a color filter of the present invention, the content of the pigment used as the component (B) is not particularly limited as long as a desired color can be formed when the colored layer of the color filter is used. Although it varies depending on the type of pigment used, it is preferably in the range of 20 to 100% by mass, and in the range of 30 to 80% by mass with respect to the solid content other than the pigment in the negative resist composition for color filters. More preferably, it is within. When the content of the pigment is in the above range, a negative resist composition for a color filter capable of forming a colored layer capable of forming a desired color can be obtained. Further, in the negative resist composition for a color filter, Can be uniformly dispersed.
In addition, the said solid content is all things other than the solvent mentioned above, and also contains the polyfunctional monomer etc. which are melt | dissolving in the solvent.

((C) Alkali-soluble resin)
In the negative resist composition for color filters of the present invention, as the alkali-soluble resin used as the component (C), those generally used for negative resists can be used, and those having solubility in an aqueous alkali solution. There is no particular limitation, and for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) ) Acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, n -Decyl (meth) acryl And at least one selected from the group consisting of silicate, benzyl (meth) acrylate, styrene, γ-methylstyrene, N-vinyl-2-pyrrolidone, glycidyl (meth) acrylate, and the like, and (meth) acrylic acid and acrylic acid. Examples include copolymers consisting of a monomer (for example, M-5600 manufactured by Toagosei Chemical Co., Ltd.), itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, and one or more of these anhydrides. it can. Moreover, although the polymer etc. which added the ethylenically unsaturated compound which has a glycidyl group or a hydroxyl group to said copolymer can be illustrated, it is not limited to these.
Among these, by adding an ethylenically unsaturated compound having a glycidyl group or a hydroxyl group to the copolymer, a polymer having an ethylenically unsaturated bond may be polymerized with a polyfunctional monomer described later at the time of exposure. This is particularly preferable in that it becomes possible and the colored layer becomes more stable.

  In the negative resist composition for color filters of the present invention, the alkali-soluble resin used as the component (C) may be used singly or in combination of two or more. It is usually in the range of 10 to 1000 parts by mass, preferably in the range of 20 to 500 parts by mass with respect to 100 parts by mass of the pigment contained in the negative resist composition for a filter. If the content of the alkali-soluble resin is too small, sufficient alkali developability may not be obtained, and if the content of the alkali-soluble resin is too large, the ratio of the pigment becomes relatively low and sufficient coloring is achieved. The concentration may not be obtained.

((D) polyfunctional monomer)
In the negative resist composition for a color filter of the present invention, the polyfunctional monomer used as the component (D) is not particularly limited as long as it can be polymerized by a photoinitiator described later, and is usually ethylenic. A compound having two or more unsaturated double bonds is used, and in particular, a polyfunctional (meth) acrylate having two or more acryloyl groups or methacryloyl groups is preferable.

  Examples of such polyfunctional (meth) acrylates include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, long chain aliphatic di (meth) acrylate, and neopentyl glycol di (Meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, stearic acid modified pentaerythritol di (meth) acrylate, propylene glycol di (meth) acrylate, glycerol di (meth) acrylate, triethylene glycol di (meth) Acrylate, tetraethylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, dicyclopentanyl (Meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene di (meth) acrylate, triglycerol di (meth) acrylate, neopentyl glycol modified trimethylolpropane di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, Methoxylated cyclohexyl di (meth) acrylate, acrylated isocyanurate, bis (acryloxyneopentyl glycol) adipate, bisphenol A di (meth) acrylate, tetrabromobisphenol A di (meth) acrylate, bisphenol S di (meth) acrylate, Bifunctional (butanediol di (meth) acrylate, phthalic acid di (meth) acrylate, phosphoric acid di (meth) acrylate, zinc di (meth) acrylate) Data) acrylate and the like.

  Examples of trifunctional or higher polyfunctional (meth) acrylates include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, glycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, penta Erythritol tetra (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, tri (meth) acrylate phosphate, tris (acryloxyethyl) isocyanurate, tris (methacryloxyethyl) isocyanurate, dipentaerythritol tetra (meta) ) Acrylate, ditrimethylolpropane tetraacrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) a Relate, dipentaerythritol penta (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, urethane tri (meth) acrylate, ester tri (meth) acrylate, urethane hexa (meth) acrylate, ester hexa (meth) acrylate, etc. Is mentioned.

These polyfunctional (meth) acrylates may be used individually by 1 type, and may be used in combination of 2 or more type. In addition, when the negative resist composition for color filter of the present invention requires excellent photocurability (high sensitivity), the polyfunctional monomer has three polymerizable double bonds (trifunctional). Those having the above are preferable, and for example, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like are suitably used.
In the negative resist composition for a color filter of the present invention, the content of the polyfunctional monomer used as the component (D) is not particularly limited, but is 100 parts by mass of the alkali-soluble resin of the component (C). Usually, about 5 to 500 parts by mass, preferably 20 to 300 parts by mass. If the content of the polyfunctional monomer is less than the above range, the photocuring may not sufficiently proceed and the exposed part may be eluted, and if the content of the polyfunctional monomer is more than the above range, the alkali developability is lowered. There is a risk.

(Photoinitiator)
In the negative resist composition for a color filter of the present invention, the photoinitiator used as the component (E) is not particularly limited, and may be appropriately selected from various known photoinitiators. it can. For example, aromatic ketones such as benzophenone, Michler ketone, 4,4′-bisdiethylaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 2-ethylanthraquinone, phenanthrene, benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether, etc. Benzoin ethers, benzoin such as methylbenzoin, ethylbenzoin, 2- (o-chlorophenyl) -4,5-phenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) Imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4,5-tria Reel imidazole dimer 2- (o-chlorophenyl) -4,5-di (m-methylphenyl) imidazole dimer, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2-trichloromethyl -5-styryl-1,3,4-oxadiazole, 2-trichloromethyl-5- (p-cyanostyryl) -1,3,4-oxadiazole, 2-trichloromethyl-5- (p-methoxy) Halomethyloxadiazole compounds such as styryl) -1,3,4-oxadiazole, 2,4-bis (trichloromethyl) -6-p-methoxystyryl-S-triazine, 2,4-bis (trichloromethyl) ) -6- (1-p-dimethylaminophenyl-1,3-butadienyl) -S-triazine, 2-trichloromethyl-4-amino-6-p-methoxystyrene Ru-S-triazine, 2- (naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-ethoxy-naphth-1-yl) -4,6-bis-trichloro Halomethyl-S-triazine compounds such as methyl-S-triazine, 2- (4-butoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2,2-dimethoxy-1, 2-diphenylethane-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 1,2-benzyl-2-dimethylamino-1- (4- Morpholinophenyl) -butanone-1,1-hydroxy-cyclohexyl-phenylketone, benzyl, benzoylbenzoic acid, methyl benzoylbenzoate, 4-benzoyl-4'-methyl Diphenyl sulfide, benzyl methyl ketal, dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, 2-n-butoxyethyl-4-dimethylaminobenzoate, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone , Isopropylthioxanthone, ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (o-acetyloxime), 4-benzoyl-methyldiphenyl sulfide, 1- Hydroxy-cyclohexyl-phenyl ketone, 2-benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2- (dimethylamino) -2-[(4-methylphenyl) ) Methyl] -1- [ -(4-morpholinyl) phenyl] -1-butanone, α-dimethoxy-α-phenylacetophenone, phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide, 2-methyl-1- [4- (methylthio) Phenyl] -2- (4-morpholinyl) -1-propanone and the like. These photoinitiators may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the negative resist composition for a color filter of the present invention, the content of the photoinitiator used as the component (E) is usually 0.01 to 100 with respect to 100 parts by mass of the polyfunctional monomer of the component (D). About part by mass, preferably 5 to 60 parts by mass. If this content is less than the above range, the polymerization reaction cannot be sufficiently caused, so that the hardness of the colored layer may not be sufficient. In some cases, the content of the pigment or the like in the solid content of the resist composition becomes relatively small, and a sufficient coloring density cannot be obtained.

((F) solvent)
In the negative resist composition for color filters of the present invention, the solvent used as the component (F) is an organic solvent that does not react with each component in the resist composition and can dissolve or disperse them. Well, not particularly limited. Specifically, alcohols such as methyl alcohol, ethyl alcohol, N-propyl alcohol, isopropyl alcohol; ether alcohols such as methoxy alcohol, ethoxy alcohol, methoxyethoxyethanol, ethoxyethoxyethanol; ethyl acetate, butyl acetate, acetic acid 3 -Esters such as methoxybutyl, methyl methoxypropionate, ethyl ethoxypropionate and ethyl lactate; ketones such as acetone, methyl isobutyl ketone and cyclohexanone; methoxyethyl acetate, methoxypropyl acetate, methoxybutyl acetate, ethoxyethyl acetate, ethyl Ether alcohol acetate such as cellosolve acetate, methoxyethoxyethyl acetate, ethoxyethoxyethyl acetate Systems; ether systems such as diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and tetrahydrofuran; aprotic amide systems such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone; lactones such as γ-butyrolactone Examples thereof include organic solvents such as unsaturated hydrocarbon systems such as benzene, toluene, xylene and naphthalene; saturated hydrocarbon systems such as n-heptane, n-hexane and n-octane.

Among these, ether alcohol acetates such as methoxyethyl acetate, ethoxyethyl acetate, ethyl cellosolve acetate, methoxyethoxyethyl acetate and ethoxyethoxyethyl acetate; ethers such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and propylene glycol diethyl ether; acetic acid Esters such as 3-methoxybutyl, methyl methoxypropionate, ethyl ethoxypropionate, and ethyl lactate can be suitably used.
Especially, as a solvent used for this invention, MBA (3-methoxybutyl acetate), PGMEA (propylene glycol monomethyl ether acetate), DMDG (diethylene glycol dimethyl ether), diethylene glycol methyl ethyl ether, PGME (propylene glycol monomethyl ether) or these Is preferable from the viewpoint of the solubility and coating suitability of the pigment dispersant.

  The content of the solvent as the component (F) in the negative resist composition for color filters of the present invention is not particularly limited as long as each component of the negative resist composition can be uniformly dissolved or dispersed. Not. In the present invention, the component excluding the solvent in the negative resist composition is preferably in the range of 5 to 40% by mass, more preferably in the range of 10 to 30% by mass. By being the said range, it can be set as the viscosity suitable for application | coating.

(Optional additive)
In the negative resist composition for color filter of the present invention, various additives such as a polymerization terminator, a chain transfer agent, a leveling agent, a plasticizer, and a surfactant are used as long as the object of the present invention is not impaired. , Antifoaming agents, silane coupling agents, ultraviolet absorbers, adhesion promoters and the like.
Among these, surfactants that can be used include, for example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene Examples include glycol dilaurate, polyethylene glycol distearate, sorbitan fatty acid esters, fatty acid-modified polyesters, and tertiary amine-modified polyurethanes. In addition, a fluorosurfactant can also be used.
Furthermore, examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, and tricresyl. Examples of the antifoaming agent and leveling agent include silicon-based, fluorine-based, and acrylic compounds.

(Preparation of negative resist composition for color filter)
As a method for preparing a negative resist composition for a color filter of the present invention, the above-mentioned (A) pigment dispersant, (B) pigment, (C) alkali-soluble resin, (D) polyfunctional monomer, (E) The photoinitiator and various additive components used as required may be any method that can be uniformly dissolved or dispersed in the solvent (F), and is not particularly limited. It can be prepared by mixing.
As a method for preparing the negative resist composition, for example, (1) a pigment dispersion is prepared by adding the above-described pigment dispersant and pigment in a solvent and dispersing using a disperser. A method of adding and mixing an alkali-soluble resin, a polyfunctional monomer, a photoinitiator, and various additive components used as desired, and (2) the above-described pigment dispersant, pigment, and alkali in a solvent A method in which a soluble resin, a polyfunctional monomer, a photoinitiator, and various additive components used as desired are simultaneously added and mixed; and (3) the above pigment dispersant and an alkali-soluble resin in a solvent. And a method in which a polyfunctional monomer, a photoinitiator, and various additive components used as desired are added and mixed, and then a pigment is added and mixed.
Among these methods, the method (1) is preferable from the viewpoint that the aggregation of the pigment can be effectively prevented and the pigment can be uniformly dispersed. In this case, the content of the solvent in the pigment dispersion is preferably in the range of 60 to 90% by mass from the viewpoint of the dispersibility of the pigment, the pigment dispersion stability over time, the chromaticity of the obtained color filter, and the like.

In the preparation of the pigment dispersion in the above method (1), as a disperser for performing a pigment dispersion treatment, a roll mill such as a two-roll or a three-roll, a ball mill such as a ball mill or a vibration ball mill, a paint shaker, a continuous Examples thereof include a bead mill such as a disk type bead mill and a continuous annular type bead mill. As a preferable dispersion condition of the bead mill, the bead diameter to be used is preferably 0.03 to 2 mm, more preferably 0.1 to 1 mm. Moreover, it is preferable to filter with a membrane filter of about 5.0 to 0.2 μm after dispersion. Thereby, the pigment dispersion liquid excellent in the dispersibility of a pigment is obtained.
In addition, when the acidic sulfate ester and / or sulfonic acid compound contained in the pigment dispersant used in the present invention has a polymerizable group, for example, after adding the pigment dispersant and the photoinitiator to the solvent. Alternatively, the pigment dispersant may be polymerized by irradiating with light after dispersing or dissolving the pigment dispersant, the pigment, and the photoinitiator in a solvent. Thus, the dispersion stability of the pigment in the negative resist composition for color filters of this invention can be improved by polymerizing pigment dispersants.

Next, the color filter of the present invention will be described.
[Color filter]
The color filter of the present invention is characterized by having a colored layer formed using the above-described negative resist composition for a color filter of the present invention.
Such a color filter of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing an example of the color filter of the present invention. According to FIG. 1, the color filter 10 of the present invention has a transparent substrate 1, a light shielding part 2, and a colored layer 3.
The color filter of the present invention has high productivity because it is excellent in alkali developability by forming a colored layer using the above-described negative resist composition for color filter of the present invention. Moreover, by being excellent in alkali developability, it is a high-quality thing with few residue of the negative resist composition for color filters in an unexposed location.

(Colored layer)
The colored layer used in the color filter of the present invention is not particularly limited as long as it is formed using the negative resist composition for color filter of the present invention described above, but is usually on a transparent substrate described later. Depending on the type of pigment formed in the opening of the light-shielding part and contained in the negative resist composition for color filter, it is composed of three or more colored patterns.
In addition, the arrangement of the colored layers is not particularly limited, and for example, a general arrangement such as a stripe type, a mosaic type, a triangle type, or a four-pixel arrangement type can be used. Moreover, the width | variety, area, etc. of a colored layer can be set arbitrarily.
The thickness of the colored layer is appropriately controlled by adjusting the coating method, the solid content concentration, the viscosity, and the like of the negative resist composition for a color filter, but is usually preferably in the range of 1 to 5 μm.

The colored layer can be formed, for example, by the following method.
First, the above-described negative resist composition for a color filter of the present invention is applied onto a transparent substrate to be described later using an application means such as a spray coating method, a dip coating method, a bar coating method, a coal coating method, or a spin coating method. Then, a wet coating film is formed.
Next, after drying the wet coating film using a hot plate or oven, it is exposed to light through a mask having a predetermined pattern, and an alkali-soluble resin and a polyfunctional monomer are photopolymerized. And a coating film of a negative resist composition for color filters. Examples of the light source used for exposure include ultraviolet rays such as a low-pressure mercury lamp, a high-pressure mercury lamp, and a metal halide lamp, and an electron beam. The exposure amount is appropriately adjusted depending on the light source used, the thickness of the coating film, and the like.
Moreover, in order to promote a polymerization reaction after exposure, you may heat-process. The heating condition is appropriately selected depending on the blending ratio of each component in the negative resist composition for color filter to be used, the thickness of the coating film, and the like.

Next, it develops using a developing solution, a coating film is formed with a desired pattern by melt | dissolving and removing an unexposed part. As the developer, a solution in which an alkali is dissolved in water or a water-soluble solvent is usually used. An appropriate amount of a surfactant or the like may be added to the alkaline solution. Further, a general method can be adopted as the developing method.
After the development treatment, the developer is usually washed and the cured coating film of the negative resist composition is dried to form a colored layer. In addition, you may heat-process in order to fully harden a coating film after image development processing. The heating conditions are not particularly limited and are appropriately selected depending on the application of the coating film.

(Shading part)
The light shielding part in the color filter of the present invention is formed in a pattern on a transparent substrate described later, and can be the same as that used as a light shielding part in a general color filter.
The pattern shape of the light shielding portion is not particularly limited, and examples thereof include a stripe shape and a matrix shape. Examples of the light-shielding portion include those obtained by dispersing or dissolving a black pigment in a binder resin, and metal thin films such as chromium and chromium oxide. The metal thin film may be a CrO _x film (x is an arbitrary number) and a laminate of two Cr films, and a CrO _x film (x is an arbitrary number) with a reduced reflectance. , CrN _y films (y is an arbitrary number) and three layers of Cr films may be laminated.
When the light-shielding part is a material in which a black colorant is dispersed or dissolved in a binder resin, the light-shielding part can be formed by any method that can pattern the light-shielding part, and is not particularly limited. For example, the photolithographic method using the photosensitive resin composition for light shielding parts, the printing method, the inkjet method etc. can be mentioned.

  In the above case, when a printing method or an inkjet method is used as a method for forming the light shielding portion, examples of the binder resin include polymethyl methacrylate resin, polyacrylate resin, polycarbonate resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, hydroxy Examples thereof include ethyl cellulose resin, carboxymethyl cellulose resin, polyvinyl chloride resin, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, maleic acid resin, polyamide resin and the like.

  In the above case, when a photolithography method is used as a method for forming the light shielding portion, the binder resin may be, for example, an acrylate-based, methacrylate-based, polyvinyl cinnamate-based, or cyclized rubber-based reactive material. A photosensitive resin having a vinyl group is used. In this case, a photopolymerization initiator may be added to the photosensitive resin composition for a light-shielding part containing a black colorant and a photosensitive resin, and further a sensitizer, a coating property improver, if necessary. A development improver, a crosslinking agent, a polymerization inhibitor, a plasticizer, a flame retardant, and the like may be added. In the present invention, the negative resist composition for color filters having a black pigment such as carbon black or titanium black as a pigment may be used as the photosensitive resin composition for the light shielding part.

  On the other hand, when the light shielding part is a metal thin film, the method for forming the light shielding part is not particularly limited as long as the light shielding part can be patterned, and for example, photolithography, vapor deposition using a mask. Method, printing method and the like.

  The thickness of the light shielding part is set to about 0.2 to 0.4 μm in the case of a metal thin film, and about 0.5 to 2 μm in the case where a black colorant is dispersed or dissolved in a binder resin. Is set.

(Transparent substrate)
The transparent substrate in the color filter of the present invention is not particularly limited as long as it is a base material transparent to visible light, and a transparent substrate used for a general color filter can be used. Specific examples include inflexible transparent rigid materials such as quartz glass, alkali-free glass, and synthetic quartz plates, or transparent flexible materials having flexibility such as transparent resin films and optical resin plates. It is done.
Although the thickness of the said transparent substrate is not specifically limited, According to the use of the color filter of this invention, the thing of about 100 micrometers-1 mm can be used, for example.
The color filter of the present invention may be one in which, for example, an overcoat layer, a transparent electrode layer, an alignment film, a columnar spacer, or the like is formed in addition to the transparent substrate, the light shielding portion, and the colored layer. .

Next, the liquid crystal display device of the present invention will be described.
[Liquid Crystal Display]
The liquid crystal display device of the present invention has the color filter of the present invention described above.
Such a liquid crystal display device of the present invention will be described with reference to the drawings. FIG. 2 is a schematic view showing an example of the liquid crystal display device of the present invention. As illustrated in FIG. 2, the liquid crystal display device 40 of the present invention includes a color filter 10, a counter substrate 20 having a TFT array substrate and the like, and a liquid crystal layer formed between the color filter 10 and the counter substrate 20. 30.
Note that the liquid crystal display device of the present invention is not limited to the configuration shown in FIG. 2, but can be a configuration generally known as a liquid crystal display device using a color filter.

The driving method of the liquid crystal display device of the present invention is not particularly limited, and a driving method generally used for a liquid crystal display device can be employed. Examples of such a drive method include a TN method, an IPS method, an OCB method, and an MVA method. In the present invention, any of these methods can be preferably used.
Further, the counter substrate can be appropriately selected and used according to the driving method of the liquid crystal display device of the present invention.
Furthermore, as the liquid crystal constituting the liquid crystal layer, various liquid crystals having different dielectric anisotropy and mixtures thereof can be used according to the driving method of the liquid crystal display device of the present invention.

As a method for forming the liquid crystal layer, a method generally used as a method for manufacturing a liquid crystal cell can be used, and examples thereof include a vacuum injection method and a liquid crystal dropping method.
In the vacuum injection method, for example, a liquid crystal cell is prepared in advance using a color filter and a counter substrate, and the liquid crystal is heated to obtain an isotropic liquid, and the liquid crystal is applied to the liquid crystal cell using the capillary effect. The liquid crystal layer can be formed by injecting in this state and sealing with an adhesive. Thereafter, the sealed liquid crystal can be aligned by slowly cooling the liquid crystal cell to room temperature.
In the liquid crystal dropping method, for example, a sealant is applied to the periphery of the color filter, the color filter is heated to a temperature at which the liquid crystal becomes isotropic, and the liquid crystal is dropped in an isotropic liquid state using a dispenser or the like. In addition, the liquid crystal layer can be formed by overlapping the color filter and the counter substrate under reduced pressure and bonding them with a sealant. Thereafter, the sealed liquid crystal can be aligned by slowly cooling the liquid crystal cell to room temperature.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

Production Example 1 Production of Block Copolymer A A 500 mL round bottom four-neck separable flask equipped with a condenser, an addition funnel, a nitrogen inlet, a mechanical stirrer, and a digital thermometer, 250 parts by mass of tetrahydrofuran (THF) and starting The agent, 5.81 parts by mass of dimethyl ketene methyltrimethylsilyl acetal, was added through an addition funnel, and the nitrogen substitution was sufficiently performed. 0.5 parts by mass of a 1 mol / L acetonitrile solution of tetrabutylammonium m-chlorobenzoate as a catalyst was injected using a syringe, and 100 parts by mass of the first monomer methyl methacrylate was added over 60 minutes using an addition funnel. It was dripped. The temperature was kept below 40 ° C. by cooling the reaction flask with an ice bath. After 1 hour, 33.3 parts by mass of dimethylaminoethyl methacrylate as the second monomer was added dropwise over 20 minutes. After reacting for 1 hour, 1 part by mass of methanol was added to stop the reaction. The obtained block copolymer THF solution was reprecipitated in hexane, purified by filtration and vacuum drying, and a block copolymer A was obtained. The block copolymer A thus obtained was confirmed by GPC (gel permeation chromatography) under the conditions of N-methylpyrrolidone, 0.01 mol / L lithium bromide added / polystyrene standard. The composition ratio MMA / DMAEMA mass ratio of methyl methacrylate (MMA) and dimethylaminoethyl methacrylate (DMAEMA) is 5/3, weight average molecular weight Mw: 8120, number average molecular weight Mn: 6840, molecular weight distribution Mw / Mn Was 1.19.

Production Example 2 Preparation of Salt Type Block Copolymer Solution A In a 100 mL round bottom flask, 25.2 parts by mass of a solvent containing propylene glycol methyl ether (PGME) and propylene glycol methyl ether acetate (PGMEA) in a predetermined ratio, Dissolve 1.8 parts by mass of block copolymer A and 2.6 parts by mass of a vinyl sulfonic acid (“VSA-H” manufactured by Asahi Kasei Finechem Co., Ltd.) as a salt-forming component (DMAEMA unit of block copolymer) 1.0 equivalent), and the mixture was stirred at a reaction temperature of 40 ° C. for 6 hours to prepare a salt-type block copolymer solution A having a solid content of 20% by mass. The acid value of the obtained block copolymer solution A was 128 mgKOH / g.

Production Example 3 Preparation of Pigment Dispersion Liquid A As a pigment dispersant, 12 parts by mass (solid content: 2.4 parts by mass) of the salt-type block copolymer solution A prepared in Production Example 2, a diketopyrrolopyrrole pigment (a ) (PR254: average primary particle size 30 nm) 3 parts by mass, 7.6 parts by mass of propylene glycol monomethyl ether acetate, 7.4 parts by mass of propylene glycol monomethyl ether (PGME), 60 parts by mass of 2.0 mm zirconia beads in mayonnaise bin Then, as a preliminary crushing, shake with a paint shaker (manufactured by Asada Tekko Co., Ltd.) for 1 hour, and then add 30 parts by mass of the dispersion and 60 parts by mass of zirconia beads having a particle size of 0.1 mm into a mayonnaise bin. For this crushing, dispersion was performed for 4 hours in a paint shaker to prepare pigment dispersion A.

Production Examples 4 to 6 Preparation of Pigment Dispersions B, C, and D As a pigment dispersant, a commercially available “Disperbyk 2000” (manufactured by Big Chemie Japan Co., Ltd., modified acrylic block copolymer, solid content concentration 40% by mass) 6 parts by mass, “Disperbyk 161” (produced by Big Chemie Japan Co., Ltd., polymer copolymer, solid content concentration 30% by mass), 8 parts by mass, “Addisper PB822” (manufactured by Ajinomoto Fine Techno Co., Ltd., basic Pigment dispersions B, C and D were prepared in the same manner as in Production Example 3, except that 2.4 parts by mass of a functional group-containing copolymer product and a solid content concentration of 100% by mass were used.

Example 1
To 23 parts by mass of pigment dispersion A (2.3 parts by mass of pigment, 1.84 parts by mass of dispersant) obtained in Production Example 3, a methacrylic acid / methyl methacrylate / benzyl methacrylate copolymer (as an alkali-soluble resin) Molar ratio: 10/30/50, weight average molecular weight: 9000, acid value: 70 mg KOH / g, active ingredient content 40% by mass) 3 parts by mass, dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd.) as a polyfunctional monomer "KAYARAD DPHA") 3.5 parts by mass, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Ciba Specialty Chemicals Co., Ltd.) as a photoinitiator ) "IRGACURE907" manufactured by the company) After adding 1.2 parts by weight and 19.3 parts by weight of PGMEA as a solvent, mix until uniform. Furthermore, the negative resist composition A for color filters was obtained by filtering with the pressure filtration apparatus which is 0.2 micrometers of mesh sizes.

Comparative Examples 1-3
In Example 1, negative resist compositions B, C, and D for color filters were prepared in the same manner as in Example 1 except that pigment dispersions B, C, and D were used instead of pigment dispersion A, respectively. Obtained.

  As described above, the color filter negative resist compositions obtained in Example 1 and Comparative Examples 1 to 3 were evaluated for pigment dispersion stability, alkali developability (development time and μm line & space resolution), and contrast. The results are shown in Table 1.

<Evaluation of pigment dispersion stability>
As an evaluation of the pigment dispersion stability of the negative resist composition for color filters obtained in each example, the pigment dispersion used for the preparation of the negative resist composition for color filters was allowed to stand at 40 ° C. for 1 week. The average particle size of the pigment particles in the pigment dispersion before and after standing was measured. For measurement of the average particle size, a “Microtrac particle size distribution meter” manufactured by Nikkiso Co., Ltd. was used.

<Alkali developability evaluation>
The negative resist composition for color filter obtained in each example was applied onto a 10 mm × 10 mm glass substrate (“NA35” manufactured by NH Techno Glass Co., Ltd.) with a thickness of 0.7 mm using a spin coater. Then, it was dried at 80 ° C. for 3 minutes using a hot plate to form a red colored layer having a thickness of 2.5 μm. This colored layer was irradiated with ultraviolet rays of 60 mJ / cm ² through a photomask using an ultra-low pressure mercury lamp. Thereafter, the glass plate on which the colored layer was formed was shower-developed using an aqueous 0.05% by mass potassium hydroxide solution as an alkaline developer, and the colored layer was completely dissolved and the colored layer was formed. The time until the glass surface appeared was measured as the development time.
After the alkali development, the substrate was further washed with ultrapure water for 60 seconds, and the resolution (μm line & space resolution) of the resulting colored layer was observed using an optical microscope.

<Contrast>
The negative resist composition for color filter obtained in each example was applied onto a glass substrate (“NA35”, manufactured by NH Techno Glass Co., Ltd.) using a spin coater, and then applied using a hot plate. By drying at 3 ° C. for 3 minutes, a red colored layer having a thickness of 2.5 μm was formed. The colored layer was irradiated with ultraviolet rays of 60 mJ / cm ² using an ultra-low pressure mercury lamp without a photomask. The glass plate on which the colored layer was formed was post-baked in a clean oven at 230 ° C., and the contrast before and after that was measured.

＊１，紫外線露光後
＊２，２３０℃でポストベーク後
なお、コントラストの欄における括弧内数値はコントラストの保持率を示す。

* 1, after UV exposure * 2, after post-baking at 230 ° C. The values in parentheses in the contrast column indicate the contrast retention.

The following can be seen from Table 1.
In the examples, the average particle diameter of the pigment particles in the pigment dispersion is in the range of 50 nm, the pigment dispersibility is good, and the dispersion stability of the pigment is also good. Further, the degree of reduction in contrast due to post-baking is small, and the alkali developability is good within 10 seconds. The resolution is also excellent at 26 μm.
On the other hand, Comparative Example 1 has good pigment dispersibility, but has poor alkali developability and cannot be developed. In Comparative Example 2, peeling occurs in the development process, and the resolution is poor at 80 μm. Comparative Example 3 has poor pigment dispersibility, low contrast, large reduction in contrast due to post-baking, partial peeling during development, and poor resolution of 80 μm.

  The negative resist composition for a color filter of the present invention provides a color filter having excellent properties such as excellent pigment dispersibility and excellent alkali developability, and a liquid crystal display device having the same. it can.

It is the schematic which shows an example of the color filter of this invention. It is the schematic which shows an example of the liquid crystal display device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2 ... Light-shielding part 3 ... Colored layer 10 ... Color filter 20 ... Opposite substrate 30 ... Liquid crystal layer 40 ... Liquid crystal display device

Claims (7)

Color filter negative having (A) pigment dispersant, (B) pigment, (C) alkali-soluble resin, (D) polyfunctional monomer, (E) photoinitiator, and (F) solvent. A resist composition in which the pigment dispersant (A) includes a structural unit (1) represented by the following general formula (I), and a structural unit (2) represented by the following general formula (II): And the amino group of the structural unit (1) and the acidic sulfate represented by the following general formula (III) and / or the sulfonic acid compound represented by the following general formula (IV) A negative resist composition for a color filter, which is a formed block copolymer.

[In formulas (I) to (IV), R ¹ is a hydrogen atom or a methyl group, R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and A is a carbon atom having 1 to 8 carbon atoms. An alkylene group, — [CH (R ⁶ ) —CH (R ⁷ ) —O] _x —CH (R ⁶ ) —CH (R ⁷ ) — or [(CH ₂ ) _y —O] _z — (CH ₂ ) _y A divalent group represented by-, R ⁴ is an alkyl group having 1 to 18 carbon atoms, benzyl group, phenyl group, pyridyl group, biphenyl group, pyridylphenyl group,-[CH (R ⁶ ) -CH (R ⁷ ) —O] _x —R ⁸ or — [(CH ₂ ) _y —O] _z —R ⁸ , wherein R ⁵ and R ⁵ ′ have a polymerizable group, each independently having 2 carbon atoms -18 alkenyl groups,-[CH (R ⁹ ) -CH (R ¹⁰ ) -O] _a -R ¹¹ or-[(CH ₂ ) _{b -O]} shows the c ^{-R 11.}
R ⁶ , R ⁷ , R ⁹ and R ¹⁰ are each independently a hydrogen atom or a methyl group, R ⁸ is a hydrogen atom, or an alkyl group having 1 to 18 carbon atoms, a benzyl group, a phenyl group, a pyridyl group, a biphenyl group, A pyridylphenyl group, —CHO, —CH ₂ CHO, —COCH═CH ₂ , —CO—C (CH ₃ ) ═CH ₂ or a monovalent group represented by —CH ₂ COOR ¹² , R ¹¹ is —COCH ═CH ₂ , or a monovalent group represented by —CO—C (CH ₃ ) ═CH ₂ , and R ¹² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
x and a are integers of 0 to 18, y and b are integers of 1 to 5, z and c are integers of 0 to 18, and m and n are integers of 1 to 200, respectively. ] Said polymerizable group, a color filter for negative resist composition according to claim 1 is a vinyl group. (B) The negative resist composition for color filters according to claim 1 or 2 , wherein the pigment has an average particle diameter of 10 to 100 nm. (D) The negative resist composition for a color filter according to any one of claims 1 to 3 , wherein the polyfunctional monomer is a compound having two or more ethylenically unsaturated bonds. The negative resist composition for a color filter according to claim 4 , wherein the compound having two or more ethylenically unsaturated bonds is a polyfunctional (meth) acrylate. A color filter characterized by having a colored layer formed is formed by using a color filter negative resist composition according to any one of claims 1-5. A liquid crystal display device comprising the color filter according to claim 6 .

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