JP5401870B2 - Negative resist composition for color filter, color filter, and liquid crystal display device - Google Patents

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 the pigment dispersant having such excellent dispersibility, a pigment dispersant using an aromatic ester, an aromatic amine, and / or a graft copolymer having a quaternary ammonium group is disclosed (for example, Patent Document 1). Has been. Also disclosed is a pigment dispersion containing a graft copolymer having a monomer containing a nitrogen atom as a main chain and a macromonomer having an ethylenically unsaturated double bond at the terminal as a side chain (for example, Patent Document 2). .

Special table 2003-517065 gazette JP 2003-26949 A

In recent years, there is 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. Further, in the pigment dispersion as disclosed in Patent Document 2, the amount of the dispersant increases as the pigment concentration in the resist composition increases. However, it was insufficient in that the developability deteriorated.

  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 graft copolymer having a specific structure is excellent in pigment dispersibility and in alkali developability, and its purpose 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 has a nitrogen-containing monomer represented by the following general formula (I), a polymer chain, and an ethylenically unsaturated double bond at its terminal It is a graft copolymer containing a polymerizable oligomer comprising a group as a copolymerization component, and further, an amino group contained in the nitrogen-containing monomer and an acidic sulfate represented by the following general formula (II) and / or the following general formula A negative resist composition for color filters, wherein the sulfonic acid compound represented by (III) is a graft copolymer in which a salt is formed;

［式（Ｉ）〜（ＩＩＩ）中、Ｒ^１は水素原子又はメチル基、Ｒ^２及びＲ^３は、それぞれ独立に水素原子又は炭素数１〜８のアルキル基、Ａは、それぞれ独立に炭素数１〜８のアルキレン基、−［ＣＨ（Ｒ^６）−ＣＨ（Ｒ^７）−Ｏ］_ｘ−ＣＨ（Ｒ^６）−ＣＨ（Ｒ^７）−又は［（ＣＨ_２）_ｙ−Ｏ］_ｚ−（ＣＨ_２）_ｙ−で示される２価の基である。
Ｒ^４及びＲ^４’は、それぞれ独立に、炭素数２〜１８のアルケニル基、−［ＣＨ（Ｒ^９）−ＣＨ（Ｒ^１０）−Ｏ］_ａ−Ｒ^８、又は−［（ＣＨ_２）_ｂ−Ｏ］_ｃ−Ｒ^８で示される１価の基である。Ｒ^６、Ｒ^７、Ｒ^９及びＲ^１０は、それぞれ独立に水素原子又はメチル基であり、Ｒ^８は、炭素数２〜１８のアルケニル基、−ＣＯ−ＣＨ＝ＣＨ_２、又は−ＣＯ−Ｃ（ＣＨ_３）＝ＣＨ _２ である。
ｘ及びａは１〜１８の整数、ｙ及びｂは１〜５の整数、ｚ及びｃは１〜１８の整数を示す。］

[In Formulas (I) to (III), 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 each independently a carbon number. 1 to 8 alkylene groups, — [CH (R ⁶ ) —CH (R ⁷ ) —O] _x —CH (R ⁶ ) —CH (R ⁷ ) — or [(CH ₂ ) _y —O] _z — ( It is a divalent group represented by CH ₂ ) _y- .
R ⁴ and R ^{4 'are} each independently, an alkenyl group having 2 to 18 carbon ^{atoms, - [CH (R 9)} -CH (R 10) -O] a -R 8, or - _{[(CH 2) b -O]} a monovalent group represented by c -R ^8. R ^{6, R} 7, ^{R 9} and ^{R 10} are each independently a hydrogen atom or a methyl group, ^{R 8} is an alkenyl group having 2 to 18 carbon atoms, _-CO-CH = CH 2, or -CO-C it is a _(CH 3) = _{CH 2.}
x and a are integers of 1 to 18, y and b are integers of 1 to 5, and z and c are integers of 1 to 18. ]

［式（ＩＶ）及び（Ｖ）中、Ｒ^１’は水素原子又はメチル基であり、Ｒ^５は炭素数１〜１８のアルキル基、ベンジル基、フェニル基、ビフェニル基、シアノ基、−［ＣＨ（Ｒ^６）−ＣＨ（Ｒ^７）−Ｏ］_ｘ−Ｒ^１１、−［（ＣＨ_２）_ｙ−Ｏ］_ｚ−Ｒ^１１、−［ＣＯ−（ＣＨ_２）_ｙ−Ｏ］_ｚ−Ｒ^１１、−ＣＯ−Ｏ−Ｒ^５’又は−Ｏ−ＣＯ−Ｒ^１３で示される１価の基である。
Ｒ^５’は、炭素数１〜１８のアルキル基、ベンジル基、フェニル基、ビフェニル基、シアノ基、−［ＣＨ（Ｒ^６）−ＣＨ（Ｒ^７）−Ｏ］_ｘ−Ｒ^１１、−［（ＣＨ_２）_ｙ−Ｏ］_ｚ−Ｒ^１１、−［ＣＯ−（ＣＨ_２）_ｙ−Ｏ］_ｚ−Ｒ^１１で示される１価の基である。
Ｒ^１１は、水素原子、あるいは炭素数１〜１８のアルキル基、ベンジル基、フェニル基、ビフェニル基、−ＣＨＯ、−ＣＨ_２ＣＨＯ又は−ＣＨ_２ＣＯＯＲ^１２で示される１価の基であり、Ｒ^１２は水素原子又は炭素数１〜５のアルキル基であり、Ｒ^１３は、炭素数１〜１８のアルキル基を示す。
ｌは１〜５の整数、ｍ及びｍ’は５〜２００の整数を示す。Ｒ^６、Ｒ^７、ｘ、ｙ、ｚは、上記と同じである。］
（４）前記重合性基が、ビニル基である上記（３）に記載のカラーフィルタ用ネガ型レジスト組成物、
（５）（Ｂ）顔料の平均粒径が、１０〜１００ｎｍである上記（１）〜（４）のいずれかに記載のカラーフィルタ用ネガ型レジスト組成物、
（６）（Ｄ）多官能性モノマーが、エチレン性不飽和結合を２個以上有する化合物である上記（１）〜（５）のいずれかに記載のカラーフィルタ用ネガ型レジスト組成物、
（７）エチレン性不飽和結合を２個以上有する化合物が、多官能（メタ）アクリレートである、上記（６）に記載のカラーフィルタ用ネガ型レジスト組成物、
（８）上記（１）〜（７）のいずれかに記載のカラーフィルタ用ネガ型レジスト組成物を用いて形成されてなる着色層を有することを特徴とするカラーフィルタ、及び
（９）上記（８）に記載のカラーフィルタを有することを特徴とする液晶表示装置、
を提供するものである。

[In the formulas (IV) and (V), R ^{1 ′} represents a hydrogen atom or a methyl group, and R ⁵ represents an alkyl group having 1 to 18 carbon atoms, a benzyl group, a phenyl group, a biphenyl group, a cyano group, — [CH _{^{(R 6) -CH (R 7}} ) -O] x -R 11, - [(CH 2) y -O] z -R 11, - [CO- (CH 2) y -O] z -R 11, It is a monovalent group represented by —CO—O—R ^{5 ′} or —O—CO—R ¹³ .
R ^{5 ′} represents an alkyl group having 1 to 18 carbon atoms, a benzyl group, a phenyl group, a biphenyl group, a cyano group, — [CH (R ⁶ ) —CH (R ⁷ ) —O] _x —R ¹¹ , — [( CH ₂ ) _y —O] _z —R ¹¹ , a monovalent group represented by — [CO— (CH ₂ ) _y —O] _z —R ¹¹ .
R ¹¹ is a hydrogen atom or a monovalent group represented by a C 1-18 alkyl group, benzyl group, phenyl group, biphenyl group, —CHO, —CH ₂ CHO or —CH ₂ COOR ¹² , ¹² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ¹³ represents an alkyl group having 1 to 18 carbon atoms.
l represents an integer of 1 to 5, and m and m ′ represent an integer of 5 to 200. R ⁶ , R ⁷ , x, y, and z are the same as described above. ]
(4 ) The negative resist composition for a color filter according to the above ( 3 ), wherein the polymerizable group is a vinyl group,
( 5 ) The negative resist composition for a color filter according to any one of (1) to ( 4 ), wherein the average particle size of the (B) pigment is 10 to 100 nm,
( 6 ) The negative resist composition for color filters according to any one of (1) to ( 5 ), wherein the polyfunctional monomer is a compound having two or more ethylenically unsaturated bonds,
( 7 ) The negative resist composition for color filters according to ( 6 ) above, wherein the compound having two or more ethylenically unsaturated bonds is a polyfunctional (meth) acrylate,
( 8 ) A color filter having a colored layer formed using the negative resist composition for a color filter according to any one of (1) to ( 7 ), and ( 9 ) the above ( A liquid crystal display device comprising the color filter according to 8 ),
Is to provide.

ADVANTAGE OF THE INVENTION According to this invention, while being excellent in pigment dispersibility, the negative resist composition for color filters which is excellent in alkali developability can be provided.
In addition, according to the present invention, by forming a colored layer using the negative resist composition for a color filter, it is possible to make the color filter excellent in alkali developability. can do. Moreover, by being excellent in alkali developability, it is possible to provide a high-quality color filter with little color filter negative resist residue at unexposed locations.
Furthermore, according to the present invention, it is possible to provide a liquid crystal display device with high quality and excellent productivity by using the color filter.

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 nitrogen-containing monomer represented by the following general formula (I), a polymer chain, and an ethylenically unsaturated double bond at its terminal. A graft copolymer containing a polymerizable oligomer composed of a group having a hydrogen atom as a copolymerization component, an amino group of the nitrogen-containing monomer and an acidic sulfate represented by the following general formula (II) and / or A graft copolymer in which a salt is formed with the sulfonic acid compound represented by the general formula (III) (hereinafter sometimes referred to as a salt-type graft copolymer).

[In Formulas (I) to (III), 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 each independently a carbon number. 1 to 8 alkylene groups, — [CH (R ⁶ ) —CH (R ⁷ ) —O] _x —CH (R ⁶ ) —CH (R ⁷ ) — or [(CH ₂ ) _y —O] _z — ( It is a divalent group represented by CH ₂ ) _y- .
R ⁴ and R ^{4 ′} 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, a biphenyl group, — [CH (R ⁹ ) —CH (R ¹⁰ ) —O] _a —R ⁸ , or — [(CH ₂ ) _b —O] _c —R ⁸ . 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, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, A monovalent group represented by benzyl group, phenyl group, biphenyl group, —CHO, —CH ₂ CHO, —CO—CH═CH ₂ , —CO—C (CH ₃ ) ═CH ₂ or —CH ₂ COOR ^12. And R ¹² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
x and a are integers of 1 to 18, y and b are integers of 1 to 5, and z and c are integers of 1 to 18. ]

According to the present invention, the pigment dispersant used is a nitrogen-containing monomer represented by the above general formula (I), a polymerizable oligomer comprising a polymer chain and a group having an ethylenically unsaturated double bond at its terminal, Is a graft copolymer containing as a copolymer component, and further represented by the amino group of the nitrogen-containing monomer and the acidic sulfate represented by the general formula (II) and / or the general formula (III). By being a salt-type graft copolymer in which a salt is formed with the sulfonic acid compound, the adsorptivity to the (B) pigment of the nitrogen-containing portion forming the salt-forming site is enhanced, while the polymer chain being grafted is (F) By being soluble in the solvent, (B) the pigment can be stabilized in the solvent (F), and as a result, (B) the pigment has excellent dispersibility and stability. It can be.
Moreover, by having the acidic sulfate ester represented by the general formula (II) and / or the sulfonic acid compound represented by the general formula (III), the amino group contained in the nitrogen-containing monomer and the general formula ( II) The salt-forming site formed by the acidic sulfate ester represented by the formula (II) and / or the sulfonic acid compound represented by the general formula (III) is highly soluble in an alkaline aqueous solution during alkali development. , It can be 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.

<Graft copolymer>
The graft copolymer comprises a nitrogen-containing monomer represented by the above general formula (I) and a polymerizable oligomer comprising a polymer chain and a group having an ethylenically unsaturated double bond at the terminal thereof as a copolymer component. Is.
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.

Each A is independently 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 is a divalent group represented by _{- 2) y -O] z -} (CH 2) y. 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 1 to 18, preferably an integer of 1 to 4, more preferably an integer of 1 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 1-18, preferably an integer of 1-4, more preferably an integer of 1-2. 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.

The polymerizable oligomer used in the present invention comprises a polymer chain and a group having an ethylenically unsaturated double bond at the terminal. The group having an ethylenically unsaturated double bond is preferably contained only at one end of the polymer chain (hereinafter sometimes referred to as “one end”). In addition, the polymerizable oligomer may be substituted with a substituent as long as the dispersion performance of the graft copolymer is not hindered. Examples of the substituent include a halogen atom.
Preferred examples of the group having an ethylenically unsaturated double bond include a (meth) acryloyl group, a vinyl group, and an allyl group. Among them, a (meth) acryloyl group and a vinyl group are preferable, and a (meth) acryloyl group is particularly preferable. preferable.

  The polymer chain of the polymerizable oligomer preferably has at least one structural unit represented by the following general formula (IV) or general formula (V).

In the formulas (IV) and (V), R ^{1 ′} is a hydrogen atom or a methyl group, and R ⁵ is an alkyl group having 1 to 18 carbon atoms, a benzyl group, a phenyl group, a biphenyl group, a cyano group, — [CH ( R ⁶ ) —CH (R ⁷ ) —O] _x —R ¹¹ , — [(CH ₂ ) _y —O] _z —R ¹¹ , — [CO— (CH ₂ ) _y —O] _z —R ¹¹ , — It is a monovalent group represented by CO—O—R ^{5 ′} or —O—CO—R ¹³ . In addition, when R ⁵ has an aromatic ring, it may have an appropriate substituent on the aromatic ring, for example, a linear or branched alkyl group having 1 to 4 carbon atoms.

  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 ^{5 ′} represents an alkyl group having 1 to 18 carbon atoms, a benzyl group, a phenyl group, a biphenyl group, a cyano group, — [CH (R ⁶ ) —CH (R ⁷ ) —O] _x —R ¹¹ , — [( CH ₂ ) _y —O] _z —R ¹¹ , a monovalent group represented by — [CO— (CH ₂ ) _y —O] _z —R ¹¹ . The alkyl group having 1 to 18 carbon atoms is as shown by the above R ^5.

R ⁶ and R ⁷ are the same as above, and R ¹¹ is a hydrogen atom or an optionally substituted alkyl group having 1 to 18 carbon atoms, benzyl group, phenyl group, biphenyl group, —CHO, a monovalent group represented by -CH ₂ CHO or _-CH 2 COOR ^{12, R 12} is a hydrogen atom or a number from 1 to 5 straight, branched, or cyclic alkyl ^{group, R 13} is, It is a C1-C18 alkyl group.
In the monovalent group represented by R ¹¹ , the substituent that may be included is, for example, a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms, a halogen atom such as F, Cl, or Br. And so on.
The alkyl group having 1 to 18 carbon atoms of R ¹³ and R ¹¹ is as described above for R ⁵ .
In the above R ⁵ and R ^{5 ′} , x, y and z are as described in the above A.

In the present invention, as R ⁵ and R ^{5 ′} , it is preferable to use those having excellent solubility with the solvent (F) described later, and specifically, the graft copolymer is constituted. Although depending on the structural unit, etc., when 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 the solvent is less polar such as pentane or hexane. When it is, it is preferable to use a pentyl group, hexyl group, heptyl group or the like.
Here, the reason why R ⁵ and R ^{5 ′} are set in this way is that the structural unit containing R ⁵ and R ^{5 ′} has solubility in the solvent, and will be described later with the amino group of the nitrogen-containing monomer. The dispersibility and stability of the pigment can be made particularly excellent when the salt-forming site formed by the acidic sulfate ester and / or the sulfonic acid compound has high adsorptivity to the pigment. Because.

Furthermore, R ⁵ and R ^{5 ′} are substitutions such as an alkoxy group, a hydroxyl group, a carboxyl group, an amino group, an epoxy group, an isocyanate group, and a hydrogen bond-forming group as long as they do not interfere with the dispersion performance of the graft copolymer. It may be substituted by a group. Moreover, after synthesizing a graft copolymer having these substituents, a compound having a functional group that reacts with the substituent and a polymerizable group may be reacted to add a polymerizable group. For example, adding a polymerizable group by reacting a graft copolymer having a carboxyl group with glycidyl (meth) acrylate, or reacting a graft copolymer having an isocyanate group with hydroxyethyl (meth) acrylate. Can do.

Among the above-described structural units, the polymer chain of the polymerizable oligomer used in the present invention preferably has a structural unit derived from alkyl (meth) acrylate, styrene, acrylonitrile, vinyl acetate, butadiene, lactone, or the like. ) Those having a structural unit derived from acrylate or lactone are more preferred.
The polymer chain of the polymerizable oligomer may be a homopolymer formed from the above-described structural unit or a copolymer.

  l is an integer of 1 to 5, preferably an integer of 2 to 5, more preferably an integer of 4 or 5. Moreover, the unit numbers m and m ′ of the structural units of the polymerizable oligomer may be integers of 5 to 200, and are not particularly limited, but are preferably in the range of 5 to 100.

  The weight average molecular weight Mw of the polymerizable oligomer is preferably in the range of 500 to 20000, and more preferably in the range of 1000 to 10,000. By being the said range, while being able to hold | maintain sufficient steric repulsion effect as a pigment dispersant, the increase in the adsorption time to the pigment by a steric effect can also be suppressed.

  Such a polymerizable oligomer may be appropriately synthesized or may be a commercially available product. Examples of commercially available products include one-end methacryloylated polymethyl methacrylate oligomers (weight average molecular weight: 6000, “AA-6 ( Product name) ": manufactured by Toagosei Chemical Co., Ltd.), one-terminal methacryloylated poly-n-butyl acrylate oligomer (weight average molecular weight: 6000," AB-6 (trade name) "manufactured by Toagosei Chemical Co., Ltd.) , One-end methacryloylated polystyrene oligomer (weight average molecular weight: 6000, “AS-6 (trade name)” manufactured by Toagosei Chemical Co., Ltd.), caprolactone-modified hydroxyethyl methacrylate (“Placcel FM5 (trade name)”: Daicel Chemical Manufactured by Co., Ltd.), caprolactone-modified hydroxyethyl acrylate ("Placcel FA10L") Trade name) "manufactured by Daicel Chemical Industries, Ltd.) are preferably used.

  In order to synthesize such a polymerizable oligomer, a living polymerization method and a radical polymerization method using a chain transfer agent are well known. The radical polymerization method is easier to use because it has a greater degree of freedom in monomer selection. For example, an oligomer having a carboxyl group at one end can be obtained by radical polymerization of a monomer in the presence of a chain transfer agent having a carboxyl group such as mercaptopropionic acid. When glycidyl methacrylate is added to this oligomer, an oligomer having a methacryloyl group at one end, that is, a polymerizable oligomer is obtained.

  In the graft copolymer used in the present invention, the repeating unit derived from the nitrogen-containing monomer is preferably contained in a proportion of 3 to 80% by mass, more preferably 5 to 50% by mass, and 10 to 40%. More preferred is mass%. If the content of the repeating unit derived from the nitrogen monomer in the graft copolymer is within the above range, the ratio of the salt-forming site formed by the amino group in the graft copolymer is appropriate, and the solvent by the polymerizable oligomer Therefore, the adsorptivity to the pigment is improved, and the dispersibility and stability of the pigment can be obtained.

  In addition, the weight average molecular weight Mw of the graft copolymer is preferably in the range of 1000 to 100,000, more preferably in the range of 3000 to 50000, and further in the range of 5000 to 30000. preferable. By being the said range, a pigment can be disperse | distributed uniformly.

  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 graft copolymer used in the present invention has the above-mentioned nitrogen-containing monomer and polymerizable oligomer as copolymer components, and further, the amino group of the nitrogen-containing monomer and a predetermined acidic sulfate and / or sulfonic acid compound And form a salt, and the structure is expressed as shown in FIG. 3, for example. In FIG. 3, in the graft copolymer, the nitrogen-containing monomer unit 51 forms a main chain by a polymerization reaction, and a polymerizable group site (group site having an ethylenically unsaturated double bond) of the polymerizable oligomer in the polymerization reaction. 52 is simultaneously polymerized with a nitrogen-containing monomer, and the polymerizable oligomer forms a side chain as a polymer chain 53 while being connected to the base portion having the ethylenically unsaturated double bond, and is an acidic sulfate and / or sulfonic acid The compound 54 forms a salt with an amino group contained in the nitrogen-containing monomer unit 51.

<Acidic sulfate and sulfonic acid compound>
Graft copolymer containing as a copolymer component a nitrogen-containing monomer represented by the general formula (I) and a polymerizable oligomer comprising a polymer chain and a group having an ethylenically unsaturated double bond at its terminal. The amino group of the nitrogen-containing monomer in the coalescence, the acidic sulfate ester and the sulfonic acid compound forming a salt are compounds having structures represented by the above general formula (II) and the above general formula (III), 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 general formula (II) and the general formula (III), R ⁴ and R ^{4 ′} 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, A biphenyl group, — [CH (R ⁹ ) —CH (R ¹⁰ ) —O] _a —R ⁸ or — [(CH ₂ ) _b —O] _c —R ⁸ is shown. In the case where R ⁴ and R ^{4 'has} 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 is as indicated by the ^{R 5.}

  The alkenyl group having 2 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. The position of the double bond of the alkenyl group is not limited, but from the viewpoint of the reactivity of the polymer obtained, it is preferable that there is a double bond at the terminal of the alkenyl group.

R ⁹ and R ¹⁰ each independently represent a hydrogen atom or a methyl group. R ⁸ is a hydrogen atom or an optionally substituted alkyl group having 1 to 18 carbon atoms, alkenyl group having 2 to 18 carbon atoms, benzyl group, phenyl group, biphenyl 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 , wherein R ¹² is a hydrogen atom or a straight chain having 1 to 5 carbon atoms. It is a chain, branched, or cyclic alkyl group.
In the monovalent group represented by R ⁸ , the substituent that may be included is, for example, a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms, a halogen atom such as F, Cl, or Br. And so on.
The alkyl group having 1 to 18 carbon atoms in R ⁸ is as shown in the above R ⁵ , and the alkenyl group having 2 to 18 carbon atoms is as shown in the above R ⁴ and R ^{4 ′.} .
In R ⁴ and R ^{4 ′} , a is an integer of 1 to 18, b is an integer of 1 to 5, and c is an integer of 1 to 18. a is preferably an integer of 1 to 4, more preferably an integer of 1 to 2, and b is preferably an integer of 1 to 4, more preferably 2 or 3. c is preferably an integer of 1 to 4, more preferably an integer of 1 to 2.

As the acidic sulfate ester represented by the general formula (II) and the sulfonic acid compound represented by the general formula (III), R ⁴ and R ^{4 ′} are each independently a methyl group, an isopropyl group, or an n-butyl group. , 2-ethylhexyl group, benzyl group, phenyl group, vinyl group, allyl group or — (CH (R ⁹ ) —CH (R ¹⁰ ) —O) _a —R ⁸ or — ((CH ₂ ) _b —O) _c -R ⁸ and R ⁸ is preferably —CO—CH═CH ₂ or —CO—C (CH ₃ ) ═CH ₂ , particularly those having a polymerizable group, that is, vinyl group, allyl A group or — (CH (R ⁹ ) —CH (R ¹⁰ ) —O) _a —R ⁸ or — ((CH ₂ ) _b —O) _c —R ⁸ , and R ⁸ is —CO—CH═CH. is ₂ or _{-CO-C (CH 3) =} CH 2 It is preferably, in particular independently vinyl group R ⁴ and R ^{4 ',} an allyl group, 2-methacryloyloxyethyl group, those which are 2-acryloyloxyethyl group.

R ⁴ in the acidic sulfate ester or R ^{4 ′} in the sulfonic acid compound is methyl group, isopropyl group, n-butyl group, 2-ethylhexyl group, benzyl group, phenyl group, vinyl group, allyl group, or — (CH (R _{^{9) -CH (R 10) -O}} ) a -R 8 or _{- ((CH 2) b -O} ) a c -R ^8, and ^{R 8} is -CO-CH = CH ₂ or -CO-C ( By being CH ₃ ) = CH ₂ , the acidic sulfuric acid ester and sulfonic acid compound can be made excellent in pigment dispersibility and alkali developability. R ⁴ and R ^{4 ′} are vinyl, allyl, or — (CH (R ⁹ ) —CH (R ¹⁰ ) —O) _a —R ⁸ or — ((CH ₂ ) _b —O) _c —R ⁸ . And when R ⁸ 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.

  Furthermore, when the acidic sulfate ester and the sulfonic acid compound contain a polymerizable group, the polymerizable groups of the acidic sulfate ester and the sulfonic acid compound can be polymerized in the vicinity of the pigment after dispersing the pigment. As a result, the pigment dispersant is fixed around the pigment, and the dispersibility and dispersion stability of the pigment can be improved.

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 0.05 to 4.0 molar equivalents , preferably 0.1 to 2.0 molar equivalents , more preferably, with respect to the amino group contained in the structural unit derived from the nitrogen-containing monomer represented by formula (I) 0.2 to 1.0 molar equivalent . 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), as described above, the nitrogen-containing monomer represented by the general formula (I), the polymer chain, and ethylene at the end thereof A graft copolymer containing a polymerizable oligomer comprising a group having a polymerizable unsaturated double bond as a copolymerization component, and further an amino group of the nitrogen-containing monomer and an acid represented by the general formula (II) A salt-type graft copolymer formed by forming a salt with a sulfate ester and / or a sulfonic acid compound represented by formula (III) is used.
By using such a salt-type graft copolymer as a pigment dispersant, the negative resist composition for a color filter of the present invention can be made excellent in pigment dispersion stability.

<Production of salt-type graft copolymer>
In the present invention, the production method of the salt-type graft copolymer used as the pigment dispersant of the component (A) includes the nitrogen-containing monomer, a polymer chain, and a group having an ethylenically unsaturated double bond at its terminal. An amino group that the nitrogen-containing monomer has, and an acidic sulfate ester represented by the general formula (II) and / or the general formula (III). Any method can be used as long as it can produce a salt formed with a sulfonic acid compound. In the present invention, for example, the nitrogen-containing monomer, the polymerizable oligomer having an ethylenically unsaturated double bond, and, if necessary, other monomers can be graft-polymerized using a known polymerization means. It is. Next, the acidic sulfate ester and / or sulfonic acid compound is added to the solvent, and the salt-type graft copolymer can be produced by stirring. In the above polymerization, additives generally used for polymerization such as a polymerization initiator and a chain transfer agent may be used.

  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 graft 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 graft copolymer is within the above range, the pigment can be dispersed uniformly, and the blending ratio of the alkali-soluble resin and the polyfunctional monomer is not relatively lowered, which is 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 within the above range, a liquid crystal display device produced using the negative resist composition for color filters of the present invention can be made to have high contrast and high quality. 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.
In addition, the average particle diameter of the pigment can be obtained by a method of directly measuring the size of primary particles from an electron micrograph. Specifically, the minor axis diameter and major axis diameter of each primary particle were measured, and the average was taken as the particle diameter of the particle. Next, for 100 or more particles, the volume (weight) of each particle was obtained by approximating the obtained particle size to a rectangular parallelepiped, and the volume average particle size was obtained and used as the average particle size. The same result can be obtained regardless of whether the electron microscope is a transmission type (TEM) or a scanning type (SEM).

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. In addition, for example, a polymer having an ethylenically unsaturated bond introduced by adding an ethylenically unsaturated compound having a reactive functional group such as a glycidyl group or a hydroxyl group to the above copolymer can be exemplified, but the present invention is not limited thereto. Is not to be done.
Among these, a polymer having an ethylenically unsaturated bond introduced, for example, by adding an ethylenically unsaturated compound having a glycidyl group or a hydroxyl group to the copolymer is polymerized with a polyfunctional monomer described later at the time of exposure. This is particularly suitable in that 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, succinic anhydride-modified pentaerythritol tetra (meth) acrylate, tri (meth) acrylate phosphate, tris (acryloxyethyl) isocyanurate, tris (methacrylic) Roxyethyl) isocyanurate, dipentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetraacrylate, alkyl-modified dipentaerythritol La (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, succinic anhydride-modified dipentaerythritol penta (meth) acrylate, urethane tri (Meth) acrylate, ester tri (meth) acrylate, urethane hexa (meth) acrylate, ester hexa (meth) acrylate and the like.

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-morpholinopropanone, 1,2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -Butanone-1,1-hydroxy-cyclohexyl-phenyl ketone, benzyl, benzoylbenzoic acid, methyl benzoylbenzoate, 4-benzoyl-4'-methyldipheny Rusulfide, benzylmethyl 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- (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 can be mentioned. 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, and isopropyl alcohol; ether alcohols such as methoxy alcohol, ethoxy alcohol, methoxyethoxyethanol, ethoxyethoxyethanol, and propylene glycol monomethyl ether; ethyl acetate, Esters such as butyl acetate, 3-methoxybutyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethyl lactate; ketones such as acetone, methyl isobutyl ketone, cyclohexanone; methoxyethyl acetate, methoxypropyl acetate, methoxybutyl acetate, Ethoxyethyl acetate, ethyl cellosolve acetate, methoxyethoxyethyl acetate, ethoxyethoxyethyl acetate Ether alcohol acetates such as tate and propylene glycol monomethyl ether acetate; ethers such as diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether and tetrahydrofuran; N, N-dimethylformamide, N, N-dimethylacetamide, N -Aprotic amides such as methylpyrrolidone; lactones such as γ-butyrolactone; unsaturated hydrocarbons such as benzene, toluene, xylene and naphthalene; saturated hydrocarbons such as n-heptane, n-hexane and n-octane Organic solvents such as systems.

Among these, ether alcohols such as propylene glycol monomethyl ether; ether alcohol acetates such as methoxyethyl acetate, ethoxyethyl acetate, ethyl cellosolve acetate, methoxyethoxyethyl acetate, ethoxyethoxyethyl acetate, propylene glycol monomethyl ether acetate; ethylene Ether systems such as glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, and propylene glycol diethyl ether; ester systems such as 3-methoxybutyl acetate, 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)
The negative resist composition for a color filter of the present invention may contain various additives as necessary within a range that does not impair the object of the present invention. Examples of the additive include a polymerization terminator, a chain transfer agent, a leveling agent, a plasticizer, a surfactant, an antifoaming agent, a silane coupling agent, an ultraviolet absorber, and an adhesion promoter.
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.
Further, 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 initiator in a solvent, Alternatively, the pigment dispersant may be polymerized after dispersing or dissolving the pigment dispersant, the pigment, and the initiator in a solvent. In particular, it is preferable to polymerize the pigment dispersants after dispersing or dissolving the pigment dispersant, the pigment, and the initiator 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. The polymerization can be carried out by light irradiation and / or heating using a photoinitiator and / or a thermal initiator as appropriate.

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 film (y is an arbitrary number) and three layers of Cr film 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 Polymerizable Oligomer A While stirring a mixed solution of 70.0 parts by mass of methyl methacrylate, 30.0 parts by mass of n-butyl methacrylate and 3.6 parts by mass of thioglycolic acid under a nitrogen stream, the temperature Warmed to 80 ° C. α, α'-Azobisisobutyronitrile (abbreviation AIBN) 0.13 parts by mass was added and reacted for 2 hours, and further 30 parts by mass of THF was added and reacted for 3 hours. After cooling, the reaction solution was diluted with 200 parts by mass of ethyl acetate and reprecipitated with 3000 parts by mass of hexane to obtain 103.7 parts by mass of white powder. Next, to 90 parts by mass of this white powder, 200 parts by mass of xylene, 12.0 parts by mass of glycidyl methacrylate, 0.13 parts by mass of N, N-dimethyldodecylamine and 0.1 parts by mass of hydroquinone were added, and at 150 ° C. Stir for 3 hours. After cooling, the reaction solution was reprecipitated with 3000 parts by mass of hexane to obtain 90 parts by mass of white powder.
The obtained polymerizable oligomer A was confirmed by GPC (gel permeation chromatography) under the conditions of N-methylpyrrolidone, 0.01 mol / L lithium bromide added / polystyrene standard, and the weight average molecular weight (Mw 4630, number average molecular weight (Mn) 2250, molecular weight distribution (Mw / Mn) was 2.06.

Production Example 2 Production of Graft Copolymer A In a reactor equipped with a cooling pipe, an addition funnel, a nitrogen inlet, a mechanical stirrer, and a digital thermometer, 20 parts by mass of polymerizable oligomer A, dimethylaminoethyl methacrylate (DMAEMA) 5.0 parts by mass, 0.25 parts by mass of 2-mercaptoethanol, and 60 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) were charged. The mixture was heated to 80 ° C. while stirring, and 20 parts by mass of polymerizable oligomer A, 5 parts by mass of DMAEMA, 0.2 part by mass of α, α′-azobisisobutyronitrile (AIBN), 2-mercaptoethanol. A mixed liquid of 0.25 parts by mass and PGMEA 60 parts by mass was dropped over 1 hour. After heating for 1 hour, a mixed solution of 0.2 parts by weight of AIBN and 20 parts by weight of PGMEA was added dropwise over 30 minutes, and further aged at the same temperature for 2 hours. The obtained graft copolymer solution was reprecipitated in hexane, purified by filtration and vacuum drying, and a graft copolymer A was obtained. The graft 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 weight average molecular weight Mw: 15590, the number average molecular weight Mn: 6570, and the molecular weight distribution Mw / Mn were 2.37.

Production Example 3 Preparation of Salt-type Graft Copolymer Solution A In a 100 mL round bottom flask, 5.0 parts by mass of graft copolymer A was dissolved in 22.76 parts by mass of propylene glycol methyl ether acetate (PGMEA) to form a salt. 0.69 parts by mass of vinyl sulfonic acid as a component (manufactured by Asahi Kasei Finechem Co., Ltd., “VSA-H”) (1.0 equivalent to the DMAEA unit of the graft copolymer) was added, and the reaction temperature was 40 ° C. By stirring for 2 hours, a salt-type graft copolymer solution A having a solid content of 20% by mass was prepared. The acid value of the obtained graft copolymer solution A was 63 mgKOH / g.

Production Example 4 Preparation of Salt Graft Copolymer Solution B In a 100 mL round bottom flask, 5.0 parts by mass of graft copolymer A was dissolved in 24.0 parts by mass of propylene glycol methyl ether acetate (PGMEA) to form a salt. Benzenesulfonic acid (manufactured by Fluka) as a component was added in an amount of 1.0 part by mass (1.0 equivalent to the DMAEA unit of the graft copolymer), and stirred at a reaction temperature of 40 ° C. for 2 hours to obtain a solid content of 20 A mass% salt-type graft copolymer solution B was prepared. The acid value of the obtained graft copolymer solution B was 60 mgKOH / g.

Production Example 5 Preparation of Pigment Dispersion A As a pigment dispersant, 12 parts by mass (2.4 parts by mass of the solid content) of the salt-type graft copolymer solution A prepared in Production Example 3, a diketopyrrolopyrrole pigment (a ) (PR254: average primary particle size 30 nm) 3 parts by mass, propylene glycol monomethyl ether acetate (PGMEA) 15 parts by mass, 2.0 mm zirconia beads 60 parts by mass in a mayonnaise bin, paint shaker (Asada Tekko Co., Ltd.) as a preliminary crushing And then, 30 parts by mass of the dispersion and 60 parts by mass of zirconia beads having a particle size of 0.1 mm are put into a mayonnaise bin, and similarly disintegrated for 4 hours with a paint shaker. And pigment dispersion A was prepared.

Production Example 6 Preparation of Pigment Dispersion B In Production Example 5, except that the amount of the salt-type graft copolymer solution B prepared in Production Example 4 was 12 parts by mass (solid content 2.4 parts by mass). Pigment dispersion B was prepared in the same manner as in Production Example 5.

Production Example 7 Preparation of Pigment Dispersion Liquid C In Production Example 5, the pigment dispersant was 8 parts by mass of “Disperbyk161” (manufactured by Big Chemie Japan Co., Ltd., solid content concentration of 30% by mass), and the amount of PGMEA used was A pigment dispersion C was prepared in the same manner as in Production Example 5 except that the amount was 19 parts by mass.

Production Example 8 Preparation of Pigment Dispersion D In Production Example 5, the pigment dispersant was 2.4 parts by weight of “Asperper PB822” (manufactured by Ajinomoto Fine Techno Co., Ltd., solid content concentration: 100% by mass), and the amount of PGMEA used A pigment dispersion D was prepared in the same manner as in Production Example 5 except that 24.6 parts by mass of

Example 1
28.5 parts by mass of pigment dispersion A (pigment 2.85 parts by mass, dispersing agent 2.28 parts by mass) obtained in Production Example 5 were mixed with methacrylic acid / methyl methacrylate / benzyl methacrylate as an alkali-soluble resin. 4.5 parts by mass (molar ratio: 10/30/50, weight average molecular weight: 9000, acid value: 70 mg KOH / g, active ingredient content: 40% by mass), dipentaerythritol hexaacrylate (Nipponization) as a polyfunctional monomer 1.8 parts by mass of “KAYARAD DPHA” manufactured by Yakuhin Co., Ltd., 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Ciba Special) as a photoinitiator After adding 1.2 parts by mass of “IRGACURE907” manufactured by Tea Chemicals Co., Ltd. and 14.0 parts by mass of PGMEA as a solvent, uniformly The mixture was further mixed and further filtered through a pressure filtration device having a mesh size of 0.2 μm to obtain a negative resist composition A for color filters.

Reference example 1
A negative resist composition B for color filters was obtained in the same manner as in Example 1, except that the pigment dispersion B obtained in Production Example 6 was used instead of the pigment dispersion A in Example 1.

Comparative Example 1
In Example 1, a negative resist composition C for color filters was obtained in the same manner as in Example 1, except that the pigment dispersion C obtained in Production Example 7 was used instead of the pigment dispersion A. .

Comparative Example 2
In Example 1, a negative resist composition D for color filters was obtained in the same manner as in Example 1 except that the pigment dispersion D obtained in Production Example 8 was used instead of the pigment dispersion A. .

As described above, with respect to the negative resist compositions for color filters obtained in Example 1, Reference Example 1 and Comparative Examples 1 and 2, the pigment dispersion stability, alkali developability (development time and μm line & space resolution), and contrast are improved. evaluated. 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 ultrahigh 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 ultrahigh pressure mercury lamp without using 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.

The following can be seen from Table 1.
In the examples, the average particle diameter of the pigment particles in the pigment dispersion is 44 nm , the pigment dispersibility is good, and the dispersion stability of the pigment is also good. Further, reduction of the contrast due to post-baking is small, alkali developability is good in 35 seconds. The resolution is also excellent at 22 μm.
In contrast, Comparative Example 1 has a longer development time and inferior contrast to the Examples. In Comparative Example 2, the development time is short and the developability is good, but the pigment dispersibility, contrast, and contrast retention are greatly inferior to those of the Examples.

  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. It is a schematic diagram which shows an example of the preferable structure of the graft copolymer used for 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 51 Nitrogen-containing monomer unit 52 Polymerizable group part of polymerizable oligomer 53 Polymer chain by polymerizable oligomer 54 Acid sulfate and / or Sulfonic acid compound

Claims (9)

Color filter negative having (A) pigment dispersant, (B) pigment, (C) alkali-soluble resin, (D) polyfunctional monomer, (E) photoinitiator, and (F) solvent. The (A) pigment dispersant comprises a nitrogen-containing monomer represented by the following general formula (I), a polymer chain, and a group having an ethylenically unsaturated double bond at its terminal. It is a graft copolymer containing a polymerizable oligomer as a copolymerization component, and further, an amino group contained in the nitrogen-containing monomer and an acidic sulfate represented by the following general formula (II) and / or the following general formula (III) A negative resist composition for a color filter, which is a graft copolymer in which a salt is formed with a sulfonic acid compound represented by the formula:

[In Formulas (I) to (III), 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 each independently a carbon number. 1 to 8 alkylene groups, — [CH (R ⁶ ) —CH (R ⁷ ) —O] _x —CH (R ⁶ ) —CH (R ⁷ ) — or [(CH ₂ ) _y —O] _z — ( It is a divalent group represented by CH ₂ ) _y- .
R ⁴ and R ^{4 'are} each independently, an alkenyl group having 2 to 18 carbon ^{atoms, - [CH (R 9)} -CH (R 10) -O] a -R 8, or - _{[(CH 2) b -O]} a monovalent group represented by c -R ^8. R ^{6, R} 7, ^{R 9} and ^{R 10} are each independently a hydrogen atom or a methyl group, ^{R 8} is an alkenyl group having 2 to 18 carbon atoms, _-CO-CH = CH 2, or -CO-C it is a _(CH 3) = _{CH 2.}
x and a are integers of 1 to 18, y and b are integers of 1 to 5, and z and c are integers of 1 to 18. ]   The negative resist composition for a color filter according to claim 1, wherein the group having the ethylenically unsaturated double bond of the polymerizable oligomer is a (meth) acryloyl group, a vinyl group, or an allyl group. The negative resist for color filters according to claim 1 or 2, wherein the polymer chain of the polymerizable oligomer has at least one structural unit represented by the following general formula (IV) or general formula (V). Composition.

[In the formulas (IV) and (V), R ^{1 ′} represents a hydrogen atom or a methyl group, and R ⁵ represents an alkyl group having 1 to 18 carbon atoms, a benzyl group, a phenyl group, a biphenyl group, a cyano group, — [CH _{^{(R 6) -CH (R 7}} ) -O] x -R 11, - [(CH 2) y -O] z -R 11, - [CO- (CH 2) y -O] z -R 11, It is a monovalent group represented by —CO—O—R ^{5 ′} or —O—CO—R ¹³ .
R ^{5 ′} represents an alkyl group having 1 to 18 carbon atoms, a benzyl group, a phenyl group, a biphenyl group, a cyano group, — [CH (R ⁶ ) —CH (R ⁷ ) —O] _x —R ¹¹ , — [( CH ₂ ) _y —O] _z —R ¹¹ , a monovalent group represented by — [CO— (CH ₂ ) _y —O] _z —R ¹¹ .
R ¹¹ is a hydrogen atom or a monovalent group represented by a C 1-18 alkyl group, benzyl group, phenyl group, biphenyl group, —CHO, —CH ₂ CHO or —CH ₂ COOR ¹² , ¹² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ¹³ represents an alkyl group having 1 to 18 carbon atoms.
l represents an integer of 1 to 5, and m and m ′ represent an integer of 5 to 200. R ⁶ , R ⁷ , x, y, and z are the same as described above. ] The negative resist composition for a color filter according to claim 3 , wherein the polymerizable group is a vinyl group. (B) The average particle diameter of a pigment is 10-100 nm, The negative resist composition for color filters in any one of Claims 1-4 . (D) The negative resist composition for a color filter according to any one of claims 1 to 5 , 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 6 , 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 1-7. A liquid crystal display device comprising the color filter according to claim 8 .

Images