CN112904669A

CN112904669A - Red-colored composition for color filter, red-colored resist composition for color filter, and display device

Info

Publication number: CN112904669A
Application number: CN202011342415.9A
Authority: CN
Inventors: 关伸章; 林明; 荒明辽一
Original assignee: Sakata Inx Corp
Current assignee: Sakata Inx Corp
Priority date: 2019-12-04
Filing date: 2020-11-25
Publication date: 2021-06-04

Abstract

The invention provides a red coloring composition for a color filter, which can inhibit sublimate caused by an organic pigment and can obtain a color filter with excellent contrast and brightness. The red colored composition for color filters contains a pyrrolopyrroledione pigment and a resin, wherein the resin has a maleimide skeleton and a sulfonic acid group.

Description

Red-colored composition for color filter, red-colored resist composition for color filter, and display device

Technical Field

The invention relates to a red coloring composition for a color filter, a red coloring resist composition for a color filter, a color filter and a display device.

Background

As an indispensable technique for achieving high image quality (high image quality) of a liquid crystal television, there is a technique for forming a high-definition color filter. The color filter includes: a color filter in which two or more types of fine stripes (stripes) having different hues are arranged in parallel on the surface of a transparent substrate such as glass, and a color filter in which fine pixels are arranged in a predetermined array in a vertical and horizontal direction; and so on.

The pixel size is as small as several tens to several hundreds of micrometers, but it is necessary to arrange the pixels in a predetermined order for each hue. In addition, the pixels of each color phase are required to have high color purity and visible light transmittance as basic performances and also to have high contrast.

As applications of liquid crystal display panels are diversified, organic pigments are often used as coloring materials (color materials) for pixels in view of reliability such as heat resistance and light resistance.

Conventionally, as an organic pigment, a red pigment dispersion for color filters using c.i. pigment red 242, c.i. pigment red 254, or c.i. pigment red 177 has been used (for example, patent document 1).

However, when c.i. pigment red 254 is used as the organic pigment, sublimates may be generated to cause a decrease in brightness and contrast, and when c.i. pigment red 242 and c.i. pigment red 177 are used, a pigment derivative is required to disperse these organic pigments, thereby causing a problem of insufficient brightness.

In recent years, brominated diketopyrrolopyrrole pigments have attracted attention as organic pigments for color filters (for example, patent documents 2 to 4).

However, even with brominated diketopyrrolopyrrole pigments, there are some levels of material for which sublimates are now problematic; in addition, in recent years, there is an increasing demand for contrast and brightness, and there is room for further improvement.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-162722

Patent document 2: japanese patent laid-open publication No. 2011-523433

Patent document 3: japanese laid-open patent publication No. 2012-155232

Patent document 4: japanese patent laid-open publication No. 158962 (Japanese patent application laid-open No. 2018)

Disclosure of Invention

Problems to be solved by the invention

In view of the above problems, an object of the present invention is to provide a red-colored composition for a color filter, which can suppress sublimation caused by an organic pigment and can obtain a color filter having excellent contrast and brightness.

Means for solving the problems

In view of the above problems, the present inventors have made extensive studies and, as a result, have found that: the present inventors have found that a red colored composition for a color filter, which can solve all the problems described above, can be obtained by using a pyrrolopyrroledione-based pigment and further a resin having a maleimide skeleton and a sulfonic acid group, and have completed the present invention.

That is, the red-colored composition for color filters of the present invention comprises a pyrrolopyrroledione-based pigment and a resin having a maleimide skeleton and a sulfonic acid group.

In the red colored composition for color filters of the present invention, it is preferable that the pyrrolopyrroledione-based pigment has a bromine group.

In addition, it is preferable that the red coloring composition for color filters further contains a sulfonate of a pyrrolopyrroledione compound.

In addition, it is preferable that the red coloring composition for color filters further contains a sulfonated compound of a compound having an azo group and a naphthol skeleton.

Preferably the resin has a phenyl maleimide based repeating unit.

Preferably, the sulfonic acid value of the resin is 0.1-20 mgKOH/g.

The present invention also relates to a red-colored resist composition for color filters obtained from the red-colored composition for color filters.

In addition, the present invention also relates to a color filter formed from the red-colored resist composition for a color filter.

In addition, the present invention also relates to a display device including the color filter.

The red-colored composition for color filters, the red-colored resist composition for color filters, the color filter, and the display device of the present invention will be described in detail below.

< Red-colored composition for color Filter >

The red colored composition for color filters comprises a pyrrolopyrrole-dione pigment having a bromo group and a resin having a maleimide skeleton and a sulfonic acid group.

(Diketopyrrolopyrrole-based pigment)

Examples of the pyrrolopyrroledione pigment include compounds represented by the following general formula (1).

[ chemical formula 1]

In the general formula (1), X represents a hydrogen atom, a chlorine atom or a bromine atom, A and B each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an optionally substituted phenyl group, -CF₃、-OR¹、-SR²、-N(R³)R⁴、-COOR⁵、-CONH₂、-CONHR⁶、-CON(R⁷)R⁸、-SO₂NH₂、-SO₂NHR⁹or-SO₂N(R¹⁰)R¹¹And R is¹～R¹¹Each independently represents an alkyl group having 1 to 12 carbon atoms, an optionally substituted phenyl group, or an optionally substituted aralkyl group.

Examples of commercially available products of the pyrrolopyrroledione-based pigment include: c.i. pigment red 254, 255, 264, 272, 291, c.i. pigment orange 71, 73 or 81, etc.

From the viewpoint of suitably improving contrast and brightness and suitably suppressing a sublimate, it is preferable that the pyrrolopyrrole-dione-based pigment has a bromine group.

Examples of the pyrrolopyrroledione-based pigment having a bromo group include compounds represented by the following chemical formulae, and examples of commercially available products thereof include c.i. pigment red 291.

[ chemical formula 2]

The content of the pyrrolopyrroledione pigment is preferably 5 to 20% by mass, more preferably 7 to 16% by mass, based on the total mass of the red-colored composition for color filters.

When the pyrrolopyrroledione-based pigment is contained in the above range, the contrast and brightness of a color filter obtained using the red-colored composition for a color filter of the present invention can be suitably improved.

When the pyrrolopyrroledione-based pigment is contained in the above range, other red pigments may be used in combination.

Examples of the other red pigments include c.i. pigment red 177 and 242.

The content of the other red pigment is, for example, 1 to 50% by mass based on the content of the pyrrolopyrroledione-based pigment.

It is preferable that the red coloring composition for color filters of the present invention does not contain the other red pigment from the viewpoint of suppressing the sublimation due to the organic pigment and suitably improving the contrast and brightness of the color filter obtained using the red coloring composition.

(resin)

The resin has a maleimide skeleton and a sulfonic acid group.

The resin can be obtained by copolymerizing a vinyl monomer, a monomer having a maleimide skeleton, and a monomer having a sulfonic acid group, for example.

Examples of the vinyl monomer include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, styrene, chloroprene, vinyl chloride, vinylidene chloride, acrylonitrile, 1-butene, butadiene, methacrylonitrile, vinyltoluene, vinyl ethyl ether, perfluorohexylethyl-thio-carbonyl-aminoethyl-methacrylate, isobornyl methacrylate, and the like, Trifluoroethyl methacrylate, hexafluoroisopropyl methacrylate, hexafluorobutyl methacrylate, a siloxane-containing vinyl monomer, and the like.

Among them, preferred are (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and benzyl (meth) acrylate, and more preferred are (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and benzyl (meth) acrylate from the viewpoints of affinity with a medium used in the microparticulation step and the ink grinding treatment step, and various physical properties of the obtained resin.

The vinyl monomer may be used singly or in combination of two or more.

In the present specification, the term (meth) acrylic acid means acrylic acid and methacrylic acid.

Examples of the monomer having a maleimide skeleton include N-cyclohexylmaleimide, N-phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-t-butylmaleimide, N-dodecylmaleimide, N-benzylmaleimide, and N-naphthylmaleimide.

Among them, N-phenylmaleimide is preferable from the viewpoint of appropriately suppressing a sublimate caused by an organic pigment.

The monomer having a maleimide skeleton may be used singly or in combination of two or more.

Examples of the monomer having a sulfonic acid group include (meth) acrylamidoalkylsulfonic acid, vinylsulfonic acid, (meth) acrylamidot-butylsulfonic acid, and styrenesulfonic acid.

Among them, acrylamide tert-butyl sulfonic acid is preferable from the viewpoint of appropriately suppressing sublimates caused by organic pigments and from the viewpoint of appropriately improving the contrast of a color filter obtained using the red-colored composition for a color filter of the present invention.

The sulfonic acid group-containing monomer may be used singly or in combination of two or more.

The mass ratio of the vinyl monomer, the monomer having a maleimide skeleton, and the monomer having a sulfonic acid group when copolymerized is as follows.

The vinyl monomer is preferably 40 to 80% by mass, more preferably 50 to 70% by mass, based on the total content (mass) of the monomers.

The monomer having a maleimide skeleton is preferably 10 to 50% by mass, more preferably 20 to 40% by mass, based on the total content of the monomers.

The sulfonic acid group-containing monomer is preferably 1 to 10% by mass, more preferably 2.5 to 5% by mass, based on the total content of the monomers.

By copolymerizing the vinyl monomer, the monomer having a maleimide skeleton, and the monomer having a sulfonic acid group in the above ranges, sublimation due to an organic pigment can be suitably suppressed, and the contrast of a color filter obtained using the red-colored composition for a color filter of the present invention can be suitably improved.

The method for copolymerizing the vinyl monomer, the monomer having a maleimide skeleton, and the monomer having a sulfonic acid group is not particularly limited, and a known method such as copolymerization can be used.

Preferably, the resin has a repeating unit based on phenylmaleimide.

The resin can appropriately suppress a sublimate caused by an organic pigment by having a repeating unit based on phenylmaleimide.

As the monomer having a maleimide skeleton described above, a resin having a repeating unit based on phenylmaleimide can be obtained by including N-phenylmaleimide.

The sulfonic acid value of the resin is preferably 0.1 to 20 mgKOH/g.

When the sulfonic acid value of the resin is in the above range, the sublimation of the organic pigment can be suitably suppressed, and the contrast of the color filter obtained using the red-colored composition for color filters of the present invention can be suitably improved.

The sulfonic acid value of the resin is more preferably 6 to 18mgKOH/g, and still more preferably 8 to 14 mgKOH/g.

When the mass ratio of the monomer having a sulfonic acid group in the case of copolymerizing the vinyl monomer, the monomer having a maleimide skeleton, and the monomer having a sulfonic acid group is in the above range, the sulfonic acid value of the resin can be appropriately adjusted.

The sulfonic acid value is a theoretical value calculated by taking the amount of potassium hydroxide required to neutralize sulfonic acid contained in 1g of the resin as milligrams.

The weight average molecular weight of the resin is preferably 1000 to 10000, more preferably 2000 to 5000, and even more preferably 2500 to 4000, from the viewpoint of the manufacturability of the resin itself and the affinity for the medium used in the microparticulation step.

The resin was dissolved as the weight average molecular weight to prepare a 0.02 mass% solution, which was passed through a filter (manufactured by GL Sciences inc., GL chromatography disk (Chromatodisk), water system 25A, pore size 0.2 μm), and then measured under the following conditions using an alias (manufactured by japan WATERS K.K) composed of a size exclusion chromatography and a refractive index detector.

Column: pLgel mixed D (Agilent (アジレント) K.2 series connection

A detector: allonce (made by WATERS corporation of Japan)

Eluent: THF (tetrahydrofuran)

Flow rate: 1.0mL/min

Sample introduction amount: 100 μ L

The content of the resin is preferably 0.1 to 5% by mass, more preferably 0.5 to 3% by mass, based on the total mass of the red-colored composition for color filters.

(sulfonate of Compound having azo group and Naphthol skeleton)

The red-colored composition for color filters of the present invention preferably further contains a sulfonated compound of a compound having an azo group and a naphthol skeleton.

The inclusion of the compound having an azo group and a naphthol skeleton can suitably improve the luminance of a color filter obtained using the red-colored composition for color filters of the present invention, and can improve the dispersibility of the pyrrolopyrroledione-based pigment, thereby improving the contrast of a color filter obtained using the red-colored composition for color filters of the present invention.

Examples of the compound having an azo group and a naphthol skeleton include c.i. pigment red 2, 112, 188, c.i. pigment brown 25, and the like.

The sulfonated compound of the compound having an azo group and a naphthol skeleton can be obtained by sulfonating the compound having an azo group and a naphthol skeleton.

The method of sulfonation is not particularly limited, and a known method can be used.

Among them, the sulfonated product of c.i. pigment red 188 is preferable from the viewpoint of further suitably improving the luminance of the color filter obtained using the red-colored composition for color filters of the present invention, and the sulfonated product of c.i. pigment red 2 is preferable from the viewpoint of suitably improving the dispersion stability of the organic pigment and improving the contrast of the color filter obtained using the red-colored composition for color filters of the present invention.

The content of the sulfonated compound having an azo group and a naphthol skeleton is preferably 0.1 to 5% by mass, more preferably 0.5 to 3% by mass, based on the total mass of the red color composition for a color filter.

(sulfonate of pyrrolopyrroledione compound)

It is preferable that the red-colored composition for color filters of the present invention further contains a sulfonate of a pyrrolopyrroledione compound.

The inclusion of the sulfonated pyrrolopyrroledione compound can suitably improve the contrast and brightness of a color filter obtained using the red-colored composition for color filters of the present invention.

Examples of the sulfonated products of the pyrrolopyrroledione compounds include sulfonated products of c.i. pigment red 254, 255, 264, 272 and 291, and c.i. pigment orange 71 and 73.

Among them, the sulfonated product of c.i. pigment orange 71 is preferable from the viewpoint of further suitably improving the contrast and brightness of the color filter obtained using the red-colored composition for a color filter.

The method for sulfonating the pyrrolopyrroledione compound is not particularly limited, and a known method can be used.

The content of the sulfonated pyrrolopyrroledione compound is preferably 0.1 to 5% by mass, more preferably 0.5 to 3% by mass, based on the total mass of the red colored composition for color filters.

When the sulfonated compound of a pyrrolopyrroledione compound is contained in the above range, both the contrast and the luminance of a color filter obtained using the red-colored composition for a color filter of the present invention can be further suitably improved.

(pigment dispersant)

Examples of the pigment dispersant include: graft polymers comprising a macromonomer having an amide skeleton in the main chain and having a methacrylate as the side chain, as described in Japanese patent laid-open Nos. 3-277673, 10-339949, 2003-517063, etc.; polyester oligomers having an aliphatic hydroxycarboxylic acid residue as described in, for example, Japanese patent application laid-open Nos. 7-96654 and 7-207178; organosiloxane polymers (KP341, manufactured by shin-Etsu chemical Co., Ltd.); (meth) acrylic (co) polymers (Polyflow Nos. 75, 90, 95, etc., available from Kyowa oil & fat chemical Co., Ltd.); a cationic surfactant (e.g., W001, manufactured by seikagaku corporation); nonionic surfactants such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, and sorbitan fatty acid esters; anionic surfactants (e.g., W004, W005, and W017, manufactured by yusho corporation); other commercially available Solsperse products (ソルスパ - ス)3000, 5000, 9000, 12000, 13240, 13940, 17000, 20000, 24000, 26000, 28000, and other Solsperse dispersants (manufactured by Zeneca (ゼネカ) Co.), Ajiser (アジスパ -PB-821, PB-822 (manufactured by Nippon Kabushiki Kaisha (Ajinomoto Fine-Technio Co., Ltd., Inc.), IONET (イソ - ネツト) S-20 (manufactured by Sanyo Kaisha Co., Ltd.), Disperbyk-160, 161, 162, 163, 164, 182, 184, BYK-LPN23590, BYK-LPN6919, BYK-LPN21116, BYK-LPN21234 (manufactured by Bikko chemical Co., Ltd.), EF46, 47, 48, and the like (EFKA Ka, manufactured by EFBV Co., Ltd.).

Among these, from the viewpoint of fine stabilization, preferred is a graft polymer having an amide skeleton in the main chain and a macromonomer composed of methacrylic acid ester as a side chain, and more specifically, preferred is a graft polymer containing vinylpyrrolidone in the main chain and a macromonomer composed of methyl methacrylate as a side chain.

The pigment dispersant may be used singly or in combination of two or more.

The content of the pigment dispersant is preferably 1 to 10% by mass, more preferably 2 to 8% by mass, based on the total mass of the red-colored composition for color filters.

(alkali-soluble resin)

It is preferable that the red-colored composition for color filters of the present invention contains an alkali-soluble resin.

The alkali-soluble resin is not particularly limited as long as it is a resin that is soluble in a developer used in a developing process for producing a color filter or an alkali developer.

Among these, the alkali-soluble resin is preferably an alkali-soluble resin having a carboxyl group, and particularly preferably a copolymer of an ethylenically unsaturated monomer having one or more carboxyl groups and another ethylenically unsaturated monomer copolymerizable therewith.

In addition, as the alkali-soluble resin having solubility in an alkaline developer, the above-mentioned copolymer of the above-mentioned vinyl monomer, the above-mentioned monomer having a maleimide skeleton and the above-mentioned monomer having a sulfonic acid group can be used.

Specific examples of the copolymer of the ethylenically unsaturated monomer having one or more carboxyl groups and another copolymerizable ethylenically unsaturated monomer include: a copolymer of a carboxyl group-containing ethylenically unsaturated monomer such as acrylic acid or methacrylic acid and at least one ethylenically unsaturated monomer selected from the group consisting of styrene, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, allyl acrylate, allyl methacrylate, benzyl acrylate, benzyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, glycerol monoacrylate, glycerol methacrylate, N-phenylmaleimide, a polystyrene macromonomer and a polymethyl methacrylate macromonomer, which are copolymerizable with the carboxyl group-containing ethylenically unsaturated monomer.

The acid value of the copolymer is preferably 50 to 300 mgKOH/g. In this case, when the acid value is less than 50mgKOH/g, the solubility in an alkaline developer tends to decrease when the colored composition of the present invention is used as a resist composition. On the other hand, if the acid value exceeds 300mgKOH/g, the solubility in an alkaline developer becomes too high, and the colored layer tends to be easily detached from the substrate and the film on the surface of the colored layer tends to be cracked when developed with the alkaline developer.

The acid value of the copolymer can be measured by a potentiometric titration method (JIS K0070: 1992).

The weight average molecular weight of the alkali-soluble resin is preferably 1000 to 10 ten thousand. When the weight average molecular weight of the alkali-soluble resin is less than 1000, solubility in an alkali developer may be increased, and development characteristics may be decreased. On the other hand, if the amount exceeds 10 ten thousand, the solubility in an organic solvent may be reduced, and if the coloring composition of the present invention is used as a resist composition, the viscosity may be increased.

The weight average molecular weight of the alkali-soluble resin can be measured by the same method as the weight average molecular weight of the resin.

The content of the alkali-soluble resin is preferably 5 to 50% by mass based on the total mass of the red-colored composition for color filters.

(organic solvent)

The red-colored composition for color filters of the present invention preferably contains an organic solvent.

The organic solvent is preferably normal pressure (1.013X 10)²kPa) of 100 to 220 ℃, an ester organic solvent, an ether ester organic solvent, a ketone organic solvent, an aromatic hydrocarbon solvent, a nitrogen-containing organic solvent, and the like.

Among the organic solvents, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexanone, 2-heptanone, ethyl 2-hydroxypropionate, 3-methyl-3-methoxybutyl propionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, n-pentyl formate, and the like are more preferable from the viewpoint of improving solubility, pigment dispersibility, coatability, and the like, and propylene glycol monomethyl ether acetate is still more preferable.

One or a combination of two or more of the above organic solvents may be used.

The content of the organic solvent is preferably 30 to 80% by mass, more preferably 35 to 75% by mass, based on the total mass of the red-colored composition for color filters, from the viewpoint of improving the solubility, pigment dispersibility, coatability, and the like of the alkali-soluble resin.

(method for producing Red-colored composition for color Filter)

The red-colored composition for color filters of the present invention can be obtained by adding the above-mentioned various components and mixing and grinding the resulting mixture.

In the method for producing a red-colored composition for color filters according to the present invention, it is preferable that the method comprises: a microparticulation step of subjecting a pyrrolopyrroledione pigment to salt milling together with a resin and a sulfonated pyrrolopyrroledione compound to obtain a microparticulated pigment; and an ink grinding step of grinding a mixture containing the microparticulated pigment and a sulfonated compound having an azo group and a naphthol skeleton.

This is because the contrast and brightness of the color filter obtained by using the red-colored composition for color filters of the present invention can be suitably improved as compared with the case where the resin and the sulfonated product of the pyrrolopyrroledione compound are added at the time of the above-mentioned ink-grinding treatment.

As the salt milling treatment, for example, the following method can be used.

An inorganic salt and an organic solvent are added to the pyrrolopyrroledione pigment, the resin, and the sulfonated pyrrolopyrroledione compound, and then kneaded under heating, thereby carrying out salt milling.

Then, the obtained kneaded mixture was put into warm water and stirred while being heated to be made into a slurry state. Then, the filtration and washing are repeated to remove inorganic salts and organic solvents, followed by drying.

As the inorganic salt, a water-soluble inorganic salt is preferably used, and for example, sodium chloride, potassium chloride, sodium sulfate, or the like is preferably used.

As the inorganic salt, an inorganic salt having a primary particle diameter of 0.5 to 50 μm is more preferably used.

The amount of the inorganic salt used is preferably 3 to 20 parts by mass, more preferably 5 to 15 parts by mass, based on 1 part by mass of the pyrrolopyrroledione pigment.

As the organic solvent used in the salt milling treatment, an organic solvent capable of suppressing crystal growth of the organic pigment is preferably used.

Examples of such organic solvents include diethylene glycol, glycerin, ethylene glycol, propylene glycol, liquid polyethylene glycol, liquid polypropylene glycol, 2- (methoxymethoxy) ethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, and dipropylene glycol monomethyl ether.

Examples of the kneading machine used for the salt milling treatment include a kneader, a two-roll mill, a three-roll mill, and a planetary mixer.

The temperature during kneading in the salt milling treatment is preferably 30 to 150 ℃. The kneading time is preferably 2 to 20 hours.

The washing after the salt milling treatment may be either water washing or hot water washing. In addition, acids, bases or solvents may also be used.

The cleaning may be repeated within a range of 1 to 5 times.

When a water-soluble inorganic salt and a water-soluble organic solvent are used as the inorganic salt and the organic solvent, the water-soluble inorganic salt and the water-soluble organic solvent can be easily removed by the washing.

The drying may be carried out by a batch or continuous drying method, for example, by heating to 80 to 120 ℃ by a heating source provided in a dryer. As the dryer, a box dryer, a belt dryer, a spray dryer, or the like can be used.

The ink grinding step is a step of grinding a mixture containing the microparticulated pigment and a sulfonated compound of a compound having an azo group and a naphthol skeleton.

The method of the above-mentioned ink-grinding treatment is not particularly limited, and for example, a bead Mill, a preliminary Mill (ready Mill), an ultrasonic homogenizer, a high-pressure homogenizer, a paint mixer (paint shaker), a ball Mill, a roll Mill, a sand Mill (sand Mill), a sand Mill (sand grinder), a dinor Mill (Dyno-Mill), a high-speed Disperser (DISPERMAT), an SC Mill, a high-pressure homogenizer (Nanomizer) or the like may be used, and the ink-grinding treatment may be carried out by a known method.

In the microparticulation step and the ink grinding step, a pigment dispersant, an alkali-soluble resin, an organic solvent, and the like may be added as necessary.

< Red-colored resist composition for color Filter >

The present invention also relates to a red-colored resist composition for color filters obtained from the above red-colored composition for color filters.

The red-colored resist composition for color filters of the present invention can be obtained by adding an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, an organic solvent, and if necessary, additives, in addition to the red-colored composition for color filters of the present invention described above.

(Red-colored composition for color filter)

The red-colored resist composition for color filters of the present invention comprises the above-described red-colored composition for color filters of the present invention.

The content of the red-colored composition for color filters is preferably 30 to 80% by mass, more preferably 40 to 75% by mass, based on the total mass of the red-colored resist composition for color filters of the present invention.

(alkali-soluble resin)

As the alkali-soluble resin, the alkali-soluble resin described in the above red-colored composition for color filters of the present invention can be suitably selected and used.

The content of the alkali-soluble resin is preferably 1 to 35% by mass, more preferably 3 to 30% by mass, based on the total mass of the red-colored resist composition for color filters of the present invention.

(photopolymerizable Compound)

Examples of the photopolymerizable compound include monomers and oligomers having one or more photopolymerizable unsaturated bonds in the molecule. The photopolymerizable unsaturated bond refers to an unsaturated bond that can be polymerized by the action of a radical or cation generated when a photopolymerization initiator described later is decomposed by an active energy ray such as ultraviolet ray or electron beam.

Examples of the monomer having one photopolymerizable unsaturated bond in the molecule include: alkyl methacrylates or alkyl acrylates such as methyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl methacrylate, methyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; aralkyl methacrylate or aralkyl acrylate such as benzyl methacrylate and benzyl acrylate; alkoxyalkyl methacrylates or alkoxyalkyl acrylates such as butoxyethyl methacrylate and butoxyethyl acrylate; aminoalkyl methacrylates or aminoalkyl acrylates such as N, N-dimethylaminoethyl methacrylate and N, N-dimethylaminoethyl acrylate; methacrylic acid esters or acrylic acid esters of polyalkylene glycol alkyl ethers such as diethylene glycol ethyl ether, triethylene glycol butyl ether, and dipropylene glycol methyl ether; methacrylic acid esters or acrylic acid esters of polyalkylene glycol aryl ethers such as hexaethylene glycol phenyl ether; isobornyl methacrylate or acrylate; glycerol methacrylate or glycerol acrylate; 2-hydroxyethyl methacrylate or 2-hydroxyethyl acrylate, and the like.

In the present specification, the term (meth) acrylate means acrylate and methacrylate.

Examples of the monomer having 2 or more photopolymerizable unsaturated bonds in the molecule include bisphenol A dimethacrylate, 1, 4-butanediol dimethacrylate, 1, 3-butanediol dimethacrylate, diethylene glycol dimethacrylate, glycerol dimethacrylate, neopentyl glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol pentamethylacrylate, bisphenol A diacrylate, 1, 4-butanediol diacrylate, 1, 3-butanediol diacrylate, diethylene glycol diacrylate, propylene glycol diacrylate, Glycerol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, and the like.

The photopolymerizable compounds may be used singly or in combination of two or more.

The content of the photopolymerizable compound is preferably 0.5 to 20% by mass, more preferably 1 to 10% by mass, based on the total mass of the red colored resist composition for color filters of the present invention.

(photopolymerization initiator)

The photopolymerization initiator is not particularly limited as long as it is a polymerization initiator capable of generating radicals and cations by irradiation with an active energy ray such as ultraviolet ray or electron beam, and examples thereof include: benzophenone, N ' -tetraethyl-4, 4 ' -diaminobenzophenone, 4-methoxy-4 ' -dimethylaminobenzophenone, benzil, 2-diethoxyacetophenone, benzoin methyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, α -hydroxyisobutylphenone, thioxanthone, 2-chlorothioxanthone, 1-hydroxycyclohexylphenylketone, t-butylanthraquinone, 1-chloroanthraquinone, 2, 3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 2-ethylanthraquinone, 1, 4-naphthoquinone, 1, 2-benzoanthraquinone, 1, 4-dimethylanthraquinone, 2-phenylanthraquinone, 2-methyl-1 [4- (methylthio) phenyl ] -2-morpholine-1-propanone, Triazine photopolymerization initiators, and the like.

The photopolymerization initiator may be used singly or in combination of two or more.

The content of the photopolymerization initiator is preferably 0.1 to 5% by mass, more preferably 0.5 to 3% by mass, based on the total mass of the red colored resist composition for color filters of the present invention.

(organic solvent)

As the organic solvent, the organic solvent described in the red-colored composition for color filters of the present invention can be suitably selected and used.

The content of the organic solvent is preferably 1 to 40% by mass, more preferably 5 to 35% by mass, based on the total mass of the red-colored resist composition for color filters of the present invention.

(other additives)

The red-colored resist composition for color filters of the present invention may further contain an additive within a range not impairing the effects of the present invention.

Examples of the additives include various additives such as a thermal polymerization inhibitor, a silane coupling agent, a titanate coupling agent, an ultraviolet absorber, and an antioxidant.

(method for producing Red-colored resist composition for color Filter)

The method for producing the red-colored resist composition for color filters of the present invention is not particularly limited, and can be obtained by mixing the above-mentioned materials by a known method.

(Red-colored resist composition for color filter)

The red colored resist composition for color filters of the present invention is applied on a glass substrate by a spin coater, prebaked (prebake) at 100 ℃ for 3 minutes, exposed to a high-pressure mercury lamp, and postbaked (postbake) at 230 ℃ for 30 minutes to obtain a coating film, and the coating film is measured by a spectrophotometer (manufactured by shimadzu corporation, UV-2500PC, C illuminant 2 °), and the measured contrast at a chromaticity (chromaticity) x of 0.6400 or more and y of 0.3290 is preferably 6200 or more, more preferably 6500 or more, further preferably 6800 or more, particularly preferably 7000 or more, and most preferably 7100 or more.

The contrast is a value when the blank is 10000.

The red-colored resist composition for color filters of the present invention is applied to a glass substrate using a spin coater, prebaked at 100 ℃ for 3 minutes, exposed to a high-pressure mercury lamp, and postbaked at 230 ℃ for 30 minutes to obtain a coating film, and the coating film is measured with a spectrophotometer (manufactured by shimadzu corporation, UV-2500PC, C light source 2 ° field of view) to obtain a luminance Y having a chromaticity x of 0.6400 and Y of 0.3290 of preferably 22.4 or more, more preferably 22.5 or more, further preferably 22.6 or more, particularly preferably 22.7 or more, and most preferably 22.8 or more.

< color Filter >

The present invention also relates to a color filter formed using the red-colored resist composition for a color filter.

The color filter of the present invention comprises a red filter portion, a green filter portion and a blue filter portion, wherein the red filter portion is formed of the red-colored resist composition for a color filter of the present invention.

The green filter and the blue filter may be formed by known materials and methods.

The color filter of the present invention can be selected and used by a known method such as a printing method or a photolithography method.

< display device >

The present invention is also a display device including the above color filter.

The display device of the present invention is not particularly limited as long as it includes the color filter of the present invention, and known liquid crystal display devices, touch panels, and the like can be given.

Effects of the invention

The invention can provide a red coloring composition for a color filter, which can inhibit sublimate caused by an organic pigment and can obtain a color filter with excellent contrast and brightness.

Detailed Description

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In addition, "%" represents "% by mass" and "parts" represents "parts by mass" unless otherwise specified.

The materials used in the examples and comparative examples are as follows.

< organic pigment >

(PR291)

C.i. pigment red 291

(PR254)

C.i. pigment red 254

(PR177)

C.i. pigment red 177

(PR242)

C.i. pigment red 242

< sulfonated Compounds >

(PR2S)

30mL of concentrated sulfuric acid was put in a 100mL Erlenmeyer flask, 10g of C.I. pigment Red 2 was put in the Erlenmeyer flask while stirring the mixture with a magnetic stirrer, and the mixture was stirred at room temperature for 30 minutes. A mixture of 50g of water and 50g of ice was placed in a 1L beaker, and the above reaction was poured into the ice water and stirred with a magnetic stirrer for 30 minutes. The resultant was filtered under reduced pressure, washed with water, and the obtained solid was dried to obtain PR 2S.

(PR188S)

PR188S was obtained in the same manner except that c.i. pigment red 2 was changed to c.i. pigment red 188 in the above-described PR2S production method.

(PO71S)

PO71S was obtained in the same manner as described above except that c.i. pigment red 2 was changed to c.i. pigment orange 71 in the above PR2S production method.

< resin >

(resin 1)

Resin 1 was obtained by random copolymerization of butyl methacrylate (50 parts by mass), methacrylic acid (5 parts by mass), N-phenylmaleimide (40 parts by mass) and acrylamido tert-butylsulfonic acid (5 parts by mass) by a known method.

The resin 1 had a sulfonic acid value of 14mgKOH/g and a weight-average molecular weight of 3000.

(resin 2)

Resin 2 was obtained by random copolymerization of butyl methacrylate (52.5 parts by mass), methacrylic acid (5 parts by mass), N-phenylmaleimide (40 parts by mass) and acrylamido tert-butyl sulfonic acid (2.5 parts by mass) by a known method.

The resin 2 had a sulfonic acid value of 7mgKOH/g and a weight-average molecular weight of 3000.

(resin 3)

The resin 3 was obtained by random copolymerization of butyl methacrylate (50 parts by mass), methacrylic acid (5 parts by mass), N-phenylmaleimide (40 parts by mass) and vinylsulfonic acid (5 parts by mass) by a known method.

The resin 3 had a sulfonic acid value of 26mgKOH/g and a weight-average molecular weight of 3000.

(resin 4)

Butyl methacrylate (70 parts by mass), methacrylic acid (5 parts by mass), N-phenylmaleimide (20 parts by mass), and acrylamido tert-butyl sulfonic acid (5 parts by mass) were randomly copolymerized by a known method to obtain resin 4.

Resin 4 had a sulfonic acid value of 14mgKOH/g and a weight-average molecular weight of 3000.

(resin 5)

Resin 5 was obtained by random copolymerization of butyl methacrylate (90 parts by mass), methacrylic acid (5 parts by mass) and acrylamido tert-butyl sulfonic acid (5 parts by mass) by a known method.

Resin 5 had a sulfonic acid value of 14mgKOH/g and a weight-average molecular weight of 3000.

(resin 6)

Butyl methacrylate (55 parts by mass), methacrylic acid (5 parts by mass), and N-phenylmaleimide (40 parts by mass) were randomly copolymerized by a known method to obtain a resin 6.

Resin 6 had a sulfonic acid value of 0mgKOH/g and a weight-average molecular weight of 3000.

The sulfonic acid value of the resins 1 to 6 is a theoretical value calculated by taking the amount of potassium hydroxide required for neutralizing 1g of sulfonic acid contained in the resin as milligrams.

The resin was dissolved to prepare a 0.02 mass% solution, the solution was passed through a filter (manufactured by GL Sciences inc., GL chromatography disk (Chromatodisk), water system 25A, pore size 0.2 μm), and then the weight average molecular weight was measured using an allence (manufactured by WATERS corporation, japan) composed of a size exclusion chromatography and a refractive index detector under the following conditions.

Column: pLgel mixed D (Agilent Co., Ltd.) x 2 pieces were connected in series

A detector: allonce (made by WATERS corporation of Japan)

Eluent: THF (tetrahydrofuran)

Flow rate: 1.0mL/min

Sample introduction amount: 100 μ L

< pigment dispersant >

(BYK-LPN23590)

BYK-LPN23590 (50% solid, AB block structure, acrylic, manufactured by Bick chemical Co., Ltd.)

< alkali soluble resin >

(ZAH110)

PHORE ZAH110 (35% solid content, available from Soocha chemical Co., Ltd.)

< organic solvent >

(PGMEA)

Propylene glycol monomethyl ether acetate

(PGME)

Propylene glycol monomethyl ether

< photopolymerizable Compound >

(DPEHA)

Dipentaerythritol hexaacrylate

< photopolymerization initiator >

(Or907)

2-benzyl- (dimethylamino) -1- (4-morpholinylphenyl) -1-butanone (product name Omnirad 907, manufactured by IGM Resins B.V. Co.)

< organic pigment in fine particle >

(Fine particle PR291-1)

Into a pot of a kneader (trade name: KHD-2, manufactured by UK.K.) were charged 10 parts by mass of PR291, 1 part by mass of PO71S, 1 part by mass of resin 1, 200 parts by mass of sodium chloride having a particle size of 20 μm, and 240 parts by mass of diethylene glycol, and kneading and salt milling were performed at 50 ℃ for 12 hours to obtain a kneaded product.

Then, 200 parts by mass of the obtained kneaded material was put into 2 liters of warm water, and stirred for 1 hour while being heated to 40 ℃ to be made into a slurry state.

Then, after removing sodium chloride and diethylene glycol by repeating filtration and washing with water, drying was performed at 40 ℃ to obtain PR291-1 in the form of fine particles.

(Fine particle PR291-2)

In the production of the above finely divided PR291-1, finely divided PR291-2 is obtained in the same manner except that resin 2 is used instead of resin 1.

(Fine particle PR291-3)

In the production of the above finely divided PR291-1, finely divided PR291-3 is obtained in the same manner except that resin 3 is used instead of resin 1.

(Fine particle PR291-4)

In the production of the above finely divided PR291-1, finely divided PR291-4 is obtained in the same manner except that resin 4 is used instead of resin 1.

(Fine particle PR291-5)

Fine particle PR291-5 was obtained in the same manner as described above except that the resin 1 was used in an amount of 0.5 parts by mass in the production of the fine particle PR 291-1.

(Fine particle PR291-6)

In the production of the above finely divided PR291-1, finely divided PR291-6 was obtained in the same manner except that PR2S was used instead of PO 71S.

(Fine particle PR291-7)

Fine particles of PR291-7 were obtained in the same manner as described above except that PO71S was used in an amount of 0.5 part by mass in the production of fine particles of PR 291-1.

(Fine particle PR291-8)

In the production of the above finely divided PR291-1, finely divided PR291-8 was obtained in the same manner except that PO71S was not used.

(Fine particle PR291-9)

In the production of the microparticulated PR291-1, microparticulated PR291-9 is obtained in the same manner except that the resin 1 is not used.

(Fine particle PR254-1)

Into a pot of a kneader (trade name: KHD-2, manufactured by UK.K.) were charged 10 parts by mass of PR254, 1 part by mass of PO71S, 1 part by mass of resin 1, 200 parts by mass of sodium chloride having a particle size of 20 μm, and 240 parts by mass of diethylene glycol, and kneading and salt milling were performed at 50 ℃ for 12 hours to obtain a kneaded product.

Then, after removing sodium chloride and diethylene glycol by repeating filtration and washing with water, drying was performed at 40 ℃ to obtain PR254-1 in the form of fine particles.

(Fine particle PR254-2)

In the production of the above-described microparticulated PR254-1, microparticulated PR254-2 is obtained in the same manner except that resin 5 is used instead of resin 1.

(Fine particle PR254-3)

In the production of the above-described microparticulated PR254-3, microparticulated PR254-3 is obtained in the same manner except that the resin 6 is used instead of the resin 1.

(Fine particle PR242)

Into a pot of a kneader (trade name: KHD-2, manufactured by UK.K.) were charged 10 parts by mass of PR242, 1 part by mass of PO71S, 1 part by mass of resin 1, 200 parts by mass of sodium chloride having a particle size of 20 μm, and 240 parts by mass of diethylene glycol, and kneading and salt-milling were carried out at 50 ℃ for 12 hours to obtain a kneaded product.

After that, the filtration and the water washing were repeated to remove sodium chloride and diethylene glycol, and then the mixture was dried at 40 ℃ to obtain PR242 in the form of fine particles.

(Fine particle PR177)

Into a pot of a kneader (trade name: KHD-2, manufactured by UK.K.) were charged 10 parts by mass of PR177, 1 part by mass of PO71S, 1 part by mass of resin 1, 200 parts by mass of sodium chloride having a particle size of 20 μm, and 240 parts by mass of diethylene glycol, and kneading and salt-milling were carried out at 50 ℃ for 12 hours to obtain a kneaded product.

After that, the solution was repeatedly filtered and washed with water to remove sodium chloride and diethylene glycol, and then dried at 40 ℃ to obtain PR177 as fine particles.

< production of Red-colored composition for color Filter >

The materials were mixed so as to have the compositions shown in Table 1, and subjected to an ink-grinding treatment for 60 minutes using a ready mill (bead diameter: 0.2nm, filling ratio 50%), to obtain red-colored compositions for color filters of examples and comparative examples.

[ Table 1]

< production of Red-colored resist composition for color Filter >

The respective materials were uniformly mixed by using a high-speed stirrer so as to have the compositions shown in table 2, and then filtered by using a membrane filter having a pore diameter of 3 μm, to obtain red-colored resist compositions for color filters of examples and comparative examples.

(preparation of sample for evaluation)

The red-colored resist compositions for color filters of examples and comparative examples were each applied to a glass substrate using a spin coater so as to have the same film thickness.

Subsequently, the specimens were pre-baked at 100 ℃ for 3 minutes, exposed to light from a high-pressure mercury lamp, and post-baked at 230 ℃ for 30 minutes to obtain respective samples for evaluation.

(evaluation of optical Properties)

The contrast and luminance Y of each of the evaluation samples were measured using a spectrophotometer (UV-2500 PC, manufactured by shimadzu corporation, C light source 2 ° field) at a chromaticity x of 0.6400 and a Y of 0.3290. The results are shown in table 2.

In contrast measurement, a blank was set to 10000.

(evaluation of sublimate)

The above-mentioned evaluation samples were observed with an optical microscope, then baked at 260 ℃ for 30 minutes, and again observed with an optical microscope, and evaluated according to the following evaluation criteria. The results are shown in table 2.

O: no sublimates were observed even after baking at 260 ℃.

And (delta): although no sublimates were observed after baking at 230 ℃, a little sublimates were observed after baking at 260 ℃.

X: sublimates were observed after baking at 230 ℃.

[ Table 2]

The red-colored resist compositions for color filters of examples 14 to 26, which used the red-colored compositions for color filters of examples 1 to 13, were confirmed to have excellent contrast and brightness of the evaluation samples and to have suppressed sublimation due to the organic pigment.

Further, from comparison of example 14 with examples 16 and 17, it was confirmed that: the contrast can be further suitably improved by using a resin having a sulfonic acid value of 0.1 to 20 mgKOH/g.

In addition, from the comparison of example 14 with example 20, it was confirmed that: the contrast can be further suitably improved by the sulfonate containing a pyrrolopyrroledione compound.

In addition, from the comparison of example 14 with examples 24 and 25, it was confirmed that: by containing the resin and the sulfonated pyrrolopyrroledione compound in the salt milling treatment, the contrast and the brightness can be further improved appropriately.

In addition, from the comparison of example 14 with example 26, it was confirmed that: by using a pyrrolopyrroledione-based pigment having a bromo group, the contrast and brightness can be further suitably improved, and the sublimate can be further suitably suppressed.

On the other hand, the brightness was insufficient for comparative example 5 using c.i. pigment red 242 as an organic pigment and comparative example 6 using c.i. pigment red 177 as an organic pigment.

In addition, in comparative example 7 using a resin having no maleimide skeleton and comparative example 8 using a resin having no sulfonic acid group, sublimates were generated, and the contrast and brightness were also insufficient.

Industrial applicability

The red-colored composition for color filters of the present invention can provide a red-colored composition for color filters that can suppress sublimation caused by an organic pigment and can provide a color filter having excellent contrast and brightness, and therefore can be suitably used as a red-colored resist composition for color filters used in liquid crystal display devices, touch panels, and the like.

Claims

1. A red-colored composition for color filters which comprises a pyrrolopyrroledione pigment and a resin, and

the resin has a maleimide skeleton and a sulfonic acid group.

2. A red-colored composition for color filters according to claim 1, wherein,

the pyrrolopyrrole-dione-based pigment has a bromine group.

3. A red-colored composition for color filters according to claim 1 or 2, further comprising a sulfonate of a pyrrolopyrroledione compound.

4. A red color composition for color filters according to any of claims 1 to 3, further comprising a sulfonated compound of a compound having an azo group and a naphthol skeleton.

5. The red coloring composition for color filters according to any one of claims 1 to 4, wherein the resin has a phenyl maleimide-based repeating unit.

6. The red coloring composition for color filters according to any one of claims 1 to 5, wherein the resin has a sulfonic acid value of 0.1mgKOH/g to 20 mgKOH/g.

7. A red-colored resist composition for color filters obtained by the red-colored composition for color filters described in any one of claims 1 to 6.

8. A color filter formed by the color filter of claim 7 using a red-colored resist composition.

9. A display device comprising the color filter of claim 8.