JP2005240000A - Pigment dispersion composition and photosensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pigment dispersion composition excellent in pigment dispersibiliity, capable of stably dispersing a pigment and capable of being preferably used in a color filter or the like without lowering various characterstics such as developability or the like, a photosensitive resin composition, and an acid group-containing copolymer. <P>SOLUTION: The pigment dispersion composition heteroaromatic ring contains a copolymer consisting of a nitrogen-containing monomer unit having a cyclic structure constitued only of a nitrogen atom and a carbon atom and a monomer unit having an acid group, and the pigment, and the other pigment dispersion composition comprises a copolymer consisting of a nitrogen-containing monomer unit having a heteroaromatic ring structure containing a nitrogen atom as an essential component and a monomer unit having an acid group, and the pigment. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a pigment dispersion composition, a photosensitive resin composition, and an acid group-containing copolymer. More specifically, a pigment dispersion composition suitable for applications such as color filters, a photosensitive resin composition containing the pigment dispersion composition, and an acid group-containing copolymer that can be suitably used for the pigment dispersion composition Regarding coalescence.

Pigment dispersion compositions are widely used in various applications such as paints and inks. In recent years, in particular, with the spread of color filters in liquid crystal display elements and solid-state imaging elements, photosensitive resin compositions for color filters. It has become important as a component of things. Conventionally, a photosensitive resin composition for a color filter includes a pigment, a dispersant, an alkali-soluble binder resin, a radical polymerizable compound, a photopolymerization initiator, and a solvent, and those composed of these components have been used.

As a technique related to a conventional pigment dispersion composition, a binder resin having an amide group and a carboxyl group, and a coloring composition containing a coloring material, N- (meth) acryloylmorpholine, N-vinylpyrrolidone, N-vinylcaprolactam It is disclosed that the obtained acrylic copolymer may be used (for example, refer patent document 1). Moreover, the Example describes the coloring composition containing the polymer obtained by superposing | polymerizing N- (meth) acryloylmorpholine, methacrylic acid, and methacrylic acid ester as binder resin. As the photosensitive coloring composition containing this coloring composition, those having carbon black as a coloring material, a dispersant, and an amide group as a binder resin are used.

In order to obtain a graft copolymer with respect to a pigment dispersion composition in which a pigment dispersant containing a graft copolymer having a nitrogen atom and an alcoholic hydroxyl group and a pigment are dispersed in an organic solvent, diethylaminoethyl ( It is disclosed that nitrogen-containing monomers such as (meth) acrylate and vinylpyridine may be used (for example, see Patent Document 2). Moreover, the Example has described the pigment dispersion composition containing the graft copolymer obtained using diethylaminoethyl acrylate, the polymethylmethacrylate which has methacryloyl group, and 2-hydroxyethyl acrylate. As the colored photosensitive composition containing the pigment dispersion composition, a pigment, a graft copolymer as a dispersant, and a copolymer of (meth) acrylic acid and (meth) acrylate as a binder polymer are used. Yes. Since the graft copolymer used as a dispersant does not have an acid group, it is non-alkali soluble.

The present invention relates to a pigment dispersion composition obtained by dispersing a pigment dispersion of a graft copolymer having a nitrogen atom and an ether group, and a pigment in an organic solvent. Diethyl (meth) acrylamide, vinylpyridine, N-vinylimidazole, N -It has been disclosed that a graft copolymer obtained from a nitrogen-containing monomer such as vinylcarbazole may be used (for example, see Patent Document 3). In addition, Examples describe a pigment dispersion composition containing a graft copolymer obtained by using 3- (N, N-dimethylamino) propylacrylamide, polymethyl methacrylate having a methacryloyl group, and methoxypolyethylene glycol methacrylate. Has been. As the colored photosensitive composition containing the pigment dispersion composition, a pigment, a graft copolymer as a dispersant, and a copolymer of (meth) acrylic acid and (meth) acrylate as a binder polymer are used. Yes.

A pigment dispersant which is a copolymer containing a monomer containing a heterocyclic hydrocarbon having an amino group or a basic cyclic nitrogen atom and a monomer having a polycaprolactone skeleton as a copolymer component, diethylaminoethyl (meth) It is disclosed that a copolymer obtained by a monomer containing a heterocyclic carbon hydrogen having a nitrogen atom, such as acrylate, vinylimidazole, vinylpyridine, or the like may be used (for example, see Patent Document 4). In the examples, it is described that a copolymer obtained by polymerizing N, N-dimethylaminoethyl methacrylate and (meth) acrylic acid caprolactone ester is used as a pigment dispersant. As the photosensitive coloring composition containing this pigment dispersant, a copolymer selected from a pigment, a copolymer as a dispersant, and a poly (meth) acrylate as an alkali-soluble binder is used. Since the copolymer used as a dispersant does not have an acid group, it is non-alkali soluble.

However, in these techniques, it is necessary to use a large amount of a dispersant in order to stably disperse the pigment. For example, in the use of a photosensitive resin composition for a color filter, the dispersant is alkali-soluble and / or Or since it does not have photosensitivity, it becomes a factor which reduces developability. In recent years, there has been a strong demand for increasing the concentration of pigments in order to increase color purity. In this case, however, it is necessary to increase the amount of the dispersant, and therefore it is necessary to increase the amount of the dispersant. As a result, since the ratio of the binder resin is relatively lowered, developability is further lowered. Therefore, there has been a demand for a technique that is extremely excellent in pigment dispersibility and that does not deteriorate characteristics such as developability due to the influence of the dispersant.
JP 2002-341533 A (2nd, 3rd, 7th, 16th to 23rd pages) JP 2000-234007 A (2nd, 9th, 14th to 16th pages) JP 2001-31885 A (2nd, 8th, 13th to 16th pages) Japanese Unexamined Patent Publication No. 2000-95992 (2nd, 5th to 6th pages)

The present invention has been made in view of the above-described present situation, and is excellent in pigment dispersibility, can stably disperse the pigment, and does not deteriorate various characteristics such as developability due to the influence of the dispersant. An object of the present invention is to provide a pigment dispersion composition, a photosensitive resin composition, and an acid group-containing copolymer that can be suitably used for applications such as filters.

As a result of various studies on the pigment dispersion composition, the present inventors have (1) a nitrogen-containing monomer unit having a ring structure composed of only nitrogen atoms and carbon atoms and a monomer unit having an acid group. And / or (2) a copolymer having a nitrogen-containing monomer unit having a heteroaromatic ring structure essentially containing a nitrogen atom and a monomer unit having an acid group is dispersed in the pigment. It has been found that, when it is used as a binder of a photosensitive resin composition, it exhibits excellent alkali solubility and developability, and can solve the above-mentioned problems in an excellent manner. did. If the binder resin can have good pigment dispersibility, it is highly preferable because it can eliminate the dispersant or stably disperse the pigment with minimal use. No binder resin having an alkalinity, particularly an alkali-soluble binder resin has been found. In the present invention, the copolymer satisfying the above (1) and / or (2) is used as a binder resin, so that the binder resin has good pigment dispersibility, and developability and exposure due to the influence of the dispersant. It was conceived that a pigment dispersion composition, a photosensitive resin composition, and an acid group-containing copolymer that can be suitably used for applications such as a color filter can be provided without degrading various characteristics such as sensitivity. It is. The copolymer satisfying the above (1) and / or (2) is a monomer having at least one nitrogen-containing monomer unit selected from the group consisting of vinylimidazole, vinylcarbazole and vinylpyridine and an acid group. A copolymer containing a specific amount of units is particularly preferred.
In addition, by imparting a radical polymerizable double bond to these binder resins, the pigment dispersibility can be further improved, and the pigment dispersion composition is extremely excellent in exposure sensitivity, coating film strength, and photopolymerizability. The inventors have found that a photosensitive resin composition can be obtained, and have reached the present invention.

That is, the present invention provides a pigment dispersion composition comprising a copolymer having a nitrogen-containing monomer unit having a ring structure composed of only nitrogen atoms and carbon atoms and a monomer unit having an acid group, and a pigment. It is.
The present invention is also a pigment dispersion composition comprising a copolymer having a nitrogen-containing monomer unit having a heteroaromatic ring structure in which a nitrogen atom is essential and a monomer unit having an acid group, and a pigment. .
The present invention is described in detail below.

The copolymer used in the pigment dispersion composition of the present invention has (1) a nitrogen-containing monomer unit having a ring structure composed only of nitrogen atoms and carbon atoms and a monomer unit having an acid group. Form, (2) It corresponds to either or both forms of the form having a nitrogen-containing monomer unit having a heteroaromatic ring structure in which a nitrogen atom is essential and a monomer unit having an acid group is there. Such a copolymer can use 1 type (s) or 2 or more types. In the present invention, the copolymer exhibits an effect as a binder resin and also exhibits an effect of dispersing the pigment (pigment dispersibility). The binder resin functions to form a coating film or the like. For example, the binder resin is cured to form a coating film or the like. Pigment dispersibility is a property that allows a pigment to be sufficiently dispersed at the time of production of a pigment dispersion composition, that is, a pigment dispersion property in a narrow sense, and a period between production of a pigment dispersion composition and actual use thereof. It also means that the pigment can be prevented from aggregating again, and the pigment can be stably dispersed, that is, dispersion stability (storage stability).

A preferred form of the present invention is that the copolymer has alkali solubility. In this case, the said copolymer can be used suitably as binder resin which comprises the photosensitive resin composition. Alkali-soluble means the property of being dissolved in an alkaline aqueous solution. In applications using a photosensitive resin composition, a coating film is formed with the photosensitive resin composition, and the film is exposed to light and developed with a developer. However, an alkaline aqueous solution that has little influence on the environment is used as the developer. In this case, the alkali-soluble copolymer is used as the binder resin of the photosensitive resin composition.

Moreover, as a content rate of the monomer unit which has an acid group, when all the structural units of a copolymer are 100 mass%, it is preferable that it is 5-40 mass%. If it is less than 5% by mass, the alkali solubility may not be sufficient, and when used in a photosensitive resin composition, good developability may not be obtained. If it exceeds 40% by mass, alkali solubility becomes excessive, and it may not be possible to obtain an excellent solvent solubility, compatibility with other components, and viscosity. Furthermore, when used in a photosensitive resin composition, the developability, transparency of the resulting coating film, and workability may not be sufficient. More preferably, it is 8-30 mass%, More preferably, it is 8-20 mass%. In addition, when introducing a radical double bond into a side chain as described later, for example, when an addition reaction to an acid group of a copolymer is performed using a monomer having an epoxy group and a double bond. The acid group disappearing by the addition reaction is not included in the content ratio of the monomer unit having the acid group.

Further, a monomer having an acid group-containing monomer unit of less than 5% by mass with respect to 100% by mass of all the structural units of the copolymer, and a monomer having a highly hydrophilic group such as a hydroxyl group or an ether group It is also possible to make it soluble in alkaline water by copolymerizing, but in that case the hydrophilicity becomes too strong, the water resistance of the coating film is greatly reduced, and the pattern swells in the process such as water washing. It may be easy to peel off. The proportion of the monomer having a hydroxyl group or an ether group is preferably less than 30% by mass, more preferably less than 20% by mass, and still more preferably less than 10% by mass.

The acid value of the copolymer is preferably 30 to 200. When the acid value is less than 30, the alkali solubility is insufficient and the developability is lowered. When the acid value exceeds 200, the hydrophilicity becomes too strong, and there is a possibility that the smoothness may be lowered or the surface may be whitened due to the rough surface of the coating film during development. Further, a salt is formed with the nitrogen-containing monomer unit, and there is a possibility that the solvent solubility is lowered or the pigment dispersibility is lowered. More preferably, it is 40-150, More preferably, it is 50-100.
A preferable form of the copolymer is a combination of a preferable range of the content ratio of the nitrogen-containing monomer unit and a preferable range of the acid value, for example, with respect to 100% by mass of all the structural units of the copolymer. The nitrogen-containing monomer unit content is preferably 0.1 to 60% by mass, and the acid value is preferably 30 to 200.

The acid value can be determined as follows, for example.
To 0.5-1 g of the polymer solution whose acid value is to be obtained, 80 ml of acetone and 10 ml of water are added and stirred to dissolve uniformly, and a 0.1 mol / L KOH aqueous solution is used as a titrant, and an automatic titrator (Hiranuma) Titration using “COM-555” manufactured by Sangyo Co., Ltd., and the acid value of the solution is measured. On the other hand, a solution prepared by adding 2 ml of acetone to 1.0 g of the above polymer solution was naturally dried at room temperature, further dried under reduced pressure (160 ° C./5 mmHg) for 5 hours, and then allowed to cool in a desiccator. Measure. Then, the acid value (mgKOH / g) of the polymer is calculated from the acid value of the solution and the resin solid content of the solution.

The nitrogen-containing monomer unit having a ring structure composed only of the nitrogen atom and the carbon atom is a monomer unit having a ring structure, and includes a substituent when the ring structure has a substituent. The atoms constituting the ring structure may be composed only of nitrogen atoms and carbon atoms. A preferable form of such a nitrogen-containing monomer unit is a form in which the ring structure does not have a substituent. Examples of the group having a ring structure composed only of a nitrogen atom and a carbon atom include 2H-pyrrolyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, pyrrolidinyl group, pyrrolinyl group, imidazolidinyl group, imidazolinyl group, pyrazolidinyl group, and pyrazolinyl. Group: pyridyl group, pyrazinyl group, pyrimidinyl group, pyridazinyl group, piperidyl group, piperazinyl group; indolizinyl group, isoindolyl group, 3H-indolyl group, indolyl group, 1H-indazolyl group, purinyl group, indolinyl group, isoindolinyl group; 4H- Quinolidinyl group, isoquinolyl group, quinolyl group, phthalazinyl group, naphthyridinyl group, quinoxalinyl group, quinazolinyl group, cinnolinyl group, pteridinyl group; 4aH-carbazolyl group, carbazolyl group, β-carboliyl Le group; phenanthridinyl group, acridinyl group, perimidinyl group, phenanthrolinyl group, phenazinyl group; and the like quinuclidinyl group.

The nitrogen-containing monomer unit having a heteroaromatic ring structure essential for the nitrogen atom is a monomer unit having a ring structure essential for the heteroaromatic ring, and the ring structure has a substituent. It may be any as long as the ring structure requires a nitrogen atom. In such a nitrogen-containing monomer unit, the ring structure may be composed of atoms other than nitrogen atoms and carbon atoms. Examples of the group having a heteroaromatic ring structure in which a nitrogen atom is essential include, for example, imidazole group, carbazole group, pyridyl group, 1,2,3,4-tetrazole group, benzimidazole group, diazole group, triazyl group, benzothiazole. Group, thiasodiazole group and the like.

The copolymer can be obtained by polymerizing monomers constituting the monomer units. That is, the copolymer of the form (1) is a copolymer of a monomer component containing a nitrogen-containing monomer having a ring structure composed only of nitrogen atoms and carbon atoms and a monomer having an acid group. In addition, the copolymer of the form (2) is a monomer containing a nitrogen-containing monomer having a heteroaromatic ring structure in which a nitrogen atom is essential and a monomer having an acid group. It can be obtained by copolymerizing the monomer component. Also, after polymerizing a monomer having an epoxy group and an unsaturated bond such as glycidyl (meth) acrylate, a nitrogen-containing compound having an amino group such as carbazole, aminoimidazole or aminopyridine is added to form nitrogen. It is also possible to use a monomer unit. These monomers may be used alone or in combination of two or more.

As the nitrogen-containing monomer, vinyl imidazole, vinyl carbazole or vinyl pyridine is preferable. In this case, the nitrogen-containing monomer unit is formed from at least one monomer selected from the group consisting of vinylimidazole, vinylcarbazole, and vinylpyridine, and such a form is preferable in the present invention. One of the forms.
More preferably, the nitrogen-containing monomer unit is formed from 1-vinylimidazole, N-vinylcarbazole, 4-vinylpyridine, or 2-vinylpyridine. Among these, 1-vinylimidazole has the most excellent dispersibility with respect to carbon black. Further, N-vinylcarbazole has been surprisingly found to have a photosensitizing action and to be photocured with a smaller exposure amount. Therefore, the form which forms a nitrogen-containing monomer unit with 1-vinylimidazole and / or N-vinylcarbazole is the most preferable. These are shown in the following general formula.

In the above copolymer, the preferable range of the content ratio of the nitrogen-containing monomer unit when the total constitutional unit of the copolymer is 100% by mass varies depending on the basicity of the nitrogen-containing monomer. For example, in 1-vinylimidazole, 0.1-10 mass% is preferable, 1-7 mass% is still more preferable, and 1-5 mass% is the most preferable. In N-vinylcarbazole, 1-60 mass% is preferable, 10-50 mass% is still more preferable, and 20-40 mass% is the most preferable. In 2-vinyl pyridine and 4-vinyl pyridine, 1-30 mass% is preferable, 2-20 mass% is still more preferable, and 3-15 mass% is the most preferable. This is presumably because the basicity and the adsorption / coordination ability for pigments differ greatly depending on the type of nitrogen-containing monomer unit. If the ratio of the nitrogen-containing monomer unit is less than the above range, the pigment dispersibility may not be sufficient, and when used in a photosensitive resin composition, the coating obtained by curing is not suitable. There is a possibility that the surface smoothness and light transmittance of the film may not be excellent. When the above range is exceeded, when used in the photosensitive resin composition, the coating film strength and the adhesion to the substrate are not sufficient, and a salt is easily formed with the acid group, and the solvent. There is a risk that the solubility in water may not be sufficient.

Examples of the monomer having an acid group include a monomer having a carboxyl group such as (meth) acrylic acid and itaconic acid; a monomer having a phosphoric acid group; a monomer having a sulfonic acid group; A monomer having a group is preferred. In addition, as described later, after polymerizing a monomer having an epoxy group and an unsaturated bond such as glycidyl (meth) acrylate, (meth) acrylic acid or the like is added, and then an acid anhydride is further added. It is also possible to use a monomer unit having an acid group. Among these, (meth) acrylic acid is preferable in terms of the balance between alkali solubility and solvent solubility.

The copolymer in the present invention preferably has a radical polymerizable double bond in the side chain. By having a radically polymerizable double bond in the side chain, the pigment dispersibility can be further improved, and when used in a photosensitive resin composition, the photopolymerizability should be excellent. Therefore, it is possible to improve the exposure sensitivity of the coating film and the coating film strength. As a method for introducing a radical polymerizable double bond into the side chain of the copolymer, for example, it is preferable to produce a copolymer using a monomer having an epoxy group and a double bond. A substituent having a radical polymerizable double bond such as a (meth) acryloyl group, a p-vinylphenyl group, or a (meth) allyl group can be introduced into the side chain.

Examples of the monomer having an epoxy group and a double bond include epoxycyclohexyl derivatives of (meth) acrylic acid such as glycidyl (meth) acrylate and 3,4-epoxycyclohexylmethyl (meth) acrylate; (Meth) acrylate alicyclic epoxy derivatives; (meth) acrylic acid β-methylglycidyl and the like. Among these, glycidyl (meth) acrylate is preferable. In particular, when glycidyl (meth) acrylate is added, the generated hydroxyl group not only improves pigment dispersibility, but also provides excellent solvent solubility and moderate hydrophilicity, and therefore exhibits excellent alkali solubility. Highly preferred. These may be used alone or in combination of two or more.

The amount of the radical polymerizable double bond possessed by the copolymer is preferably 0.2 to 10 mmol / g. When it is less than 0.2 mmol / g, for example, when used in a photosensitive resin composition, exposure sensitivity and strength after curing may not be sufficient. If it exceeds 10 mmol / g, sufficient storage stability may not be obtained. More preferably, it is 0.5-5 mmol / g, and most preferably 0.8-3 mmol / g.

The amount of the radical polymerizable double bond can be measured, for example, as follows.
An operation of adding 2 ml of acetone to 1.5 g of a polymer solution to be determined for the amount of radical polymerizable double bonds and dissolving it, followed by air drying at room temperature and further drying under reduced pressure (70 ° C./5 mmHg) for 1 hour 3 Repeat several times to remove the solvent from the polymer solution.
200 mg of the sample obtained as described above, 30-40 mmHg of chloroform as an internal standard substance, and about 3 g of dimethyl sulfoxide-d6 as an NMR solvent are weighed into a screw tube, shaken and dissolved well, and an NMR apparatus (Varian) Manufactured by “GEMINI2000”). From the integral ratio of the C = C peak (δ 5.6 to 6.2, 2H) and the chloroform peak (δ 8.3, 1H), the mass of the polymer, and the mass of chloroform in the obtained chart, C = C amount (mmol / g) is calculated.

As the copolymer in the present invention, in addition to the nitrogen-containing monomer unit and the monomer unit having an acid group, a structural unit derived from a (meth) acrylic acid ester may be included. In addition, a structural unit derived from another monomer copolymerizable with the monomer forming the monomer unit may be included.

Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, etc. Is mentioned. Among these, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, and benzyl (meth) acrylate are preferable. These may be used alone or in combination of two or more. As a content rate of the structural unit derived from (meth) acrylic acid ester, it is preferable that the content rate of the nitrogen-containing monomer and the monomer having an acid group is in the above-described range, for example, 20 to 95. It is preferable to set it as the mass%. More preferably, it is 40-95 mass%.

Examples of the other copolymerizable monomer include, for example, a polymerizable macromonomer having an ethylenically unsaturated group at the terminal, such as a poly (meth) acrylate macromonomer and a polystyrene macromonomer, and a polymerization containing an ether group. Examples of the polymerizable monomer and the other monomer include one or more of styrene, vinyl ketone, α-methyl styrene, acrylonitrile, methyl vinyl ketone, ethylene, propylene, vinyl chloride, vinyl acetate and the like.

When the polymerizable macromonomer is copolymerized, the pigment dispersibility is improved due to the steric effect of the polymer chain.
When the polymerizable monomer containing the ether group is copolymerized, the pigment dispersibility is improved due to the steric effect of the polymer chain, and the alkali solubility is also improved because the hydrophilicity is increased.
From the viewpoint of heat resistance, styrene, α-methylstyrene, and polymethyl methacrylate macromonomer are preferable.

As a content rate of the structural unit derived from the other monomer which can be copolymerized, when the total structural unit of the copolymer is 100% by mass, the content is preferably 50% by mass or less. More preferably, it is 0-30 mass%.

The polymerizable macromonomer may be a commercially available product or may be appropriately synthesized. Examples of the commercially available product include one-end methacryloylated polysterene oligomer (Mn = 6000, trade name: AS -6, manufactured by Toa Gosei Chemical Co., Ltd.), one-end methacryloylated polymethyl methacrylate oligomer (Mn = 6000, trade name: AA-6, manufactured by Toa Gosei Chemical Co., Ltd.), one-end methacryloylated poly-n-butyl acrylate oligomer (Mn = 6000, trade name: AB-6, manufactured by Toa Gosei Chemical Co., Ltd.), one-end methacryloylated polymethyl methacrylate / 2-hydroxyethyl methacrylate oligomer (Mn = 7000, trade name: AA-714, Toa Gosei Chemical Industries) ), One-end methacryloylated polybutyl methacrylate / 2-hydroxy Ethyl methacrylate oligomer (Mn = 7000, trade name: 707S, manufactured by Toa Gosei Chemical Co., Ltd.), single-end methacryloylated poly 2-ethylhexyl methacrylate / 2-hydroxyethyl methacrylate oligomer (Mn = 7000, trade name: AY-707S, AY) -714S, manufactured by Toagosei Chemical Industry Co., Ltd.).

The polymerizable monomer having an ether group is not particularly limited as long as it has an ether group and is polymerizable, and can be appropriately selected from known ones. For example, polyethylene glycol mono (meth) Examples include acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol polypropylene glycol mono (meth) acrylate, polytetramethylene glycol monomethacrylate, etc., and these may be commercially available products or may be appropriately synthesized. Good. Examples of the commercially available products include methoxypolyethyleneglycol metacrine (trade names: NK esters M-20G, M-40G, M-90G, M-230G (above, manufactured by Shin-Nakamura Chemical Co., Ltd.)); trade name: Plenmer PME- 100, PME-200, PME-400, PME-1000, PME-2000, PME-4000 (manufactured by NOF Corporation), polyethylene glycol monomethacrylate (trade names: Plenmer PE-90, PE-200, PE- 350, manufactured by NOF Corporation), polypropylene glycol monomethacrylate (trade names: Plenmer PP-500, PP-800, PP-1000, manufactured by NOF Corporation), polyethylene glycol polypropylene glycol monomethacrylate (trade name: Plenmer 70PEP-370B, Nippon Oil & Fats Co., Ltd.) Triethylene glycol polytetramethylene glycol monomethacrylate (trade name: BLEMMER 55PET-800, NOF Corporation), polypropylene glycol polytetramethylene glycol monomethacrylate (trade name: BLEMMER NHK-5050, manufactured by NOF Corporation) and the like.

As a method for producing the copolymer, for example, (1) a nitrogen-containing monomer and a monomer having an acid group are essential, and a (meth) acrylic acid ester and / or the copolymer as necessary. A method of polymerizing a monomer component containing other possible monomers and adding a monomer having an epoxy group and a double bond to the obtained polymer (a) (hereinafter referred to as production method (1) (2) A nitrogen-containing monomer and a monomer having an epoxy group and a double bond are essential, and a (meth) acrylic acid ester and / or the above copolymer can be used as necessary. A monomer component containing another monomer is polymerized, and a monomer having an acid group is added to the obtained polymer (b), and then a saturated or unsaturated polybasic acid anhydride is further added. A method of adding (hereinafter also referred to as production method (2)) and the like are suitable.

In the method for producing a copolymer in the present invention, as a method for polymerizing a monomer component, for example, polymerization is preferably performed using a polymerization initiator, and a chain transfer agent is used as necessary to adjust the molecular weight. Can be used. Moreover, it can carry out by solution polymerization, block polymerization, etc., and can carry out also by a batch type or a continuous type.

Examples of the polymerization initiator include cumene hydroperoxide, diisopropylbenzene peroxide, di-t-butyl peroxide, lauryl peroxide, benzoyl peroxide, t-butyl peroxyisopropyl carbonate, and t-butyl peroxy-2. Organic peroxides such as ethylhexanoate and t-amylperoxy-2-ethylhexanoate; 2,2′-azobis (isobutyronitrile), 1,1′-azobis (cyclohexanecarbonitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl-2,2′-azobis (2-methylpropionate), dimethyl-2,2′-azobis (2-methylpropionate), etc. 1 type or 2 types or more, such as an azo compound. Among these, t-butylperoxy-2-ethylhexanoate, dimethyl-2,2′-azobis (2-methylpropionate) in terms of decomposition temperature, availability, and handling Is preferred. What is necessary is just to set the usage-amount of a polymerization initiator suitably according to the combination of the monomer component to be used, reaction conditions, etc.

Examples of the chain transfer agent include thiol chain transfer agents such as n-dodecanethiol, α-methylstyrene dimer, etc., but the chain transfer effect is high and the residual monomer can be reduced. Furthermore, it is preferable to use n-dodecanethiol because it is easily available.
As a method for adding the chain transfer agent to the reaction vessel, a continuous charging method such as dropping or divided charging can be applied. In addition, the chain transfer agent may be introduced alone into the reaction vessel, or may be confused in advance with a monomer component, a solvent, or the like.

In the above polymerization method, a solvent may be used as necessary, but as the solvent, those used in usual radical polymerization reaction can be used. For example, ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, etc. Esters; alcohols such as methanol, ethanol, isopropanol, n-butanol, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; one or two of chloroform, dimethyl sulfoxide, and the like More than species. Among these, ethers, ketones, and esters are preferable. More preferred are propylene glycol monomethyl ether acetate and 3-methoxybutyl acetate. It is preferable to use the same kind of such a polymerization solvent and the organic solvent used for the manufacturing method of the pigment dispersion composition mentioned later.
As the usage-amount of the said polymerization solvent, when the total monomer component used is 100 mass%, it is preferable that it is 5-500 mass%, for example. More preferably, it is 50-200 mass%.

In the above polymerization method, as a method for adding the monomer component and the polymerization initiator to the reaction vessel, all the monomer components are charged into the reaction vessel, and copolymerization is performed by adding the polymerization initiator into the reaction vessel. A method in which a part of the monomer component is charged into a reaction vessel and copolymerization is performed by adding a polymerization initiator and the remaining monomer component in the reaction vessel; a polymerization solvent is charged in the reaction vessel, A method of adding the whole amount of the monomer and the polymerization initiator is suitable. Among these, the molecular weight distribution of the obtained polymer can be narrowed (sharp), and the reaction can be easily controlled, so that a polymerization initiator and a monomer component are sequentially dropped into a reaction vessel. It is preferable to carry out the copolymerization, and it is preferable to add a polymerization initiator even after the monomer component is added, since the residual monomer can be reduced.

In the above polymerization method, the polymerization reaction conditions and the like may be appropriately set depending on the polymerization method used, the solvent, the polymerization initiator, and the chain transfer agent. For example, the polymerization temperature is preferably 50 to 150 ° C. The reaction time is preferably 0.5 to 24 hours.

Although the polymer (a) in the said manufacturing method (1) and the polymer (b) in the said manufacturing method (2) can be obtained by the said polymerization method, as a weight average molecular weight of these polymers, 1000-150,000 are obtained. It is preferable that More preferably, it is 2000-60000, More preferably, it is 3000-40000.

In the copolymer production method (2), after adding the monomer having an acid group to the polymer (b), a saturated or unsaturated polybasic acid is used for dehydration and dealcoholization. An anhydride will be added.
Examples of the polybasic acid anhydride include succinic anhydride, methyl succinic anhydride, maleic anhydride, citraconic anhydride, glutaric anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, Dibasic acid anhydrides such as methyl nadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride; trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, methylcyclohexene tetracarboxylic anhydride, etc. One type or two or more types such as acid anhydrides of basic acid or higher are preferred.

The amount of the polybasic acid anhydride used is preferably 5 to 70% by mass with respect to 100% by mass of the polymer after the monomer having an acid group is added to the polymer (b). . If the amount used is outside the above range, good alkali solubility may not be obtained. When used in a photosensitive resin composition, developability, transparency of the resulting coating film, and workability are good. There is a risk that it will not be. More preferably, it is 10-50 mass%.

In the addition reaction in the production method of the copolymer, that is, in the production method (1), an addition reaction of a monomer having an epoxy group and a double bond, and in the production method (2), a single monomer having an acid group is used. In the addition reaction of the monomer, the polymerization temperature is preferably 50 to 150 ° C., for example. If it is less than 50 ° C., the addition reaction may not proceed sufficiently. If it exceeds 150 ° C., gelation may occur during the addition reaction. More preferably, it is 80-140 degreeC, More preferably, it is 90-120 degreeC. Moreover, as reaction time, it is preferable to set it as 0.5 to 24 hours, for example. More preferably, it is 1 to 15 hours.

In the above addition reaction, a catalyst can be used as necessary. As the catalyst, for example, when the compound to be added has an epoxy group, an amine compound such as triethylamine is preferable. The amount of the catalyst used is preferably 0.01 to 30% by mass with respect to 100% by mass of the polymer to be added. If the amount used is less than 0.01% by mass, the addition reaction may not proceed sufficiently. If it exceeds 30% by mass, the polymer as the adduct may be colored, and the catalyst may be precipitated without being dissolved. More preferably, it is 0.05-5 mass%, More preferably, it is 0.1-2 mass%.

In the above addition reaction, a gas having an inhibitory effect may be introduced into the reaction system, or an inhibitor may be added. Thereby, the gelatinization at the time of addition reaction can fully be prevented. As the gas having a prohibitive effect, a gas containing oxygen that does not enter the explosion range of the substance in the system is preferable. For example, oxygen / nitrogen = 5/95 (volume ratio) mixed gas, oxygen / argon = 5/95 ( Volume ratio) Mixed gas, air and the like.
The introduction method and the introduction amount of the gas having the prohibition effect may be appropriately set according to the form of the reaction vessel, the temperature of the addition reaction, the amount of the compound to be added, and the like.

Examples of the inhibitor include one or more of hydroquinone, methoquinone, 2,6-di-t-butylphenol, 2,2′-methylenebis (4-methyl-6-t-butylphenol), phenothiazine, and the like. Can be mentioned. The amount of the inhibitor used is preferably 0.005 to 5% by mass when the total of the polymer to be added and the compound to be added is 100% by mass. If the amount used is less than 0.005% by mass, a sufficient prohibition effect may not be obtained. If it exceeds 5% by mass, the exposure sensitivity may not be sufficient when used in a photosensitive resin composition. More preferably, it is 0.03-3 mass%, More preferably, it is 0.05-1.5 mass%.
Further, a gas having a prohibiting effect and an inhibitor may be used in combination, and in this case, the amount of the inhibitor to be used can be reduced or the prohibiting effect can be increased.

As the molecular weight of the copolymer in the pigment dispersant of the present invention, the weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (hereinafter also referred to as “GPC”) is preferably 1000 to 150,000. . When the weight average molecular weight is less than 1000, suitable alkali solubility cannot be obtained, and the curability may not be sufficient. Therefore, when used in a photosensitive resin composition, developability Otherwise, the strength of the cured coating film may not be sufficiently improved. If it exceeds 150,000, the alkali solubility and compatibility with other compounds will not be sufficient, and when used in a photosensitive resin composition, the developability and the transparency of the coating film may not be sufficiently improved. There is. More preferably, it is 2000-60000, More preferably, it is 3000-40000.

As the pigment in the present invention, for example, organic pigments, inorganic pigments such as metal oxides such as iron, cobalt, aluminum, cadmium, lead, copper, titanium, magnesium, chromium, zinc, and antimony, and composite oxides are preferable. . These may be used alone or in combination of two or more.

Examples of the organic pigment include C.I. among organic compounds classified as pigments in the color index (CI: issued by The Society of Dyers and Colorists). I. Pigment Yellow 24, C.I. I. Pigment Yellow 31, C.I. I. Pigment Yellow 53, C.I. I. Pigment Yellow 83, C.I. I. Pigment Yellow 136;
C. I. Pigment Orange 43; C.I. I. Pigment Red 105, C.I. I. Pigment Red 176, C.I. I. Pigment Red 177; C.I. I. Pigment Violet 14, C.I. I. Pigment Violet 29; C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 22, C.I. I. Pigment Blue 28; C.I. I. Pigment Green 15, C.I. I. Pigment Green 25, C.I. I. Pigment Green 36; C.I. I. Pigment Brown 28; C.I. I. Pigment Black 1, C.I. I. Pigment Black 7 and carbon black are preferably used.
More preferred is carbon black as a black pigment, or phthalocyanine green (CI Pigment Green 36) as a green pigment, and more preferred is phthalocyanine green. Further, the form of the pigment is preferably particulate.

As a method for producing the pigment dispersion composition, it is preferable to mix the copolymer and the pigment in the present invention using an organic solvent. For example, the copolymer, the pigment and the organic solvent described later are added to a reaction vessel. A method of adding and mixing at once; A method of adding a composition obtained by mixing a copolymer and a pigment in advance to an organic solvent; and adding a copolymer and a pigment separately to an organic solvent in advance. A method of mixing the obtained liquid; a method of dispersing the pigment in an organic solvent and then adding a copolymer to the obtained dispersion; a method of adding a copolymer to the organic solvent and then dispersing the pigment in the obtained liquid And the like. Among these methods, a method in which a copolymer, a pigment, and an organic solvent are added to a reaction vessel at a time and mixed is preferable.

Examples of the organic solvent include those similar to the polymerization solvent in the polymerization method described above, but it is preferable to use the same solvent as the polymerization solvent.
In the pigment dispersion composition, the mass ratio of the copolymer, the pigment and the organic solvent is preferably copolymer / pigment / organic solvent = 1-30 / 1-30 / 40-98. More preferably, it is 1-15 / 5-25 / 50-90, More preferably, it is 5-15 / 5-25 / 50-85.

In the present invention, it is preferable to eliminate or minimize the use of the dispersant. However, when a dispersant is used to further improve the dispersibility of the pigment, the amount used thereof is the pigment dispersion composition. It is preferable to set it as 10 mass% or less with respect to 100 mass% of things. More preferably, it is 5 mass% or less. When using a dispersant, it is preferable to use a surfactant. For example, polyethylene glycol alkyl ethers such as polyethylene glycol lauryl ether and polyethylene glycol stearyl ether; polyethylene glycol such as polyethylene glycol octyl phenyl ether and polyethylene glycol nonyl phenyl ether Aryl ethers; polyethylene glycol diesters such as polyethylene glycol dilaurate and polyethylene glycol distearate; fluorinated surfactants such as BM-1000 (manufactured by BM Heavy); cationic surfactants such as organosiloxane polymers One type or two or more types of anionic surfactants such as anionic polymer high molecular unsaturated polycarboxylic acid. In addition, intermediates of pigments, polymer dispersants, and the like are also preferable, and derivatives of organic dyes in which a substituent is introduced into the organic dye as a base are particularly preferable. Examples of the organic dye as the base include one or more of azo, phthalocyanine, quinacridone, anthraquinone, perylene, thioindico, dioxazine, metal complex, and the like. As a substituent, 1 type (s) or 2 or more types, such as a hydroxyl group, a carboxyl group, a sulfone group, a carbonamide group, a sulfonamide group, are mentioned.

The present invention further includes a nitrogen-containing monomer unit having a heteroaromatic ring structure in which a nitrogen atom is essential, a monomer unit having an acid group, and an acid group having a polymerizable double bond in the side chain. It is also a containing copolymer. The nitrogen-containing monomer unit having a heteroaromatic ring structure in which a nitrogen atom is essential, the monomer unit having an acid group, the form having a polymerizable double bond in the side chain, and the like are the same as described above. Such a copolymer is excellent in pigment dispersibility, can disperse the pigment stably, and is suitable for uses such as a color filter without deteriorating various properties such as developability due to the influence of the dispersant. It can be used.

The present invention is also a photosensitive resin composition comprising the above-mentioned pigment dispersion composition, and further a radical polymerizable compound and a photopolymerizable initiator.
In the photosensitive resin composition, the copolymer in the pigment dispersion composition has both functions as a binder resin and a pigment dispersant.
As the method for producing the photosensitive resin composition, for example, a case where a photosensitive resin composition is prepared by adding a radical polymerizable compound and a photopolymerization initiator to the pigment dispersion composition, a pigment, a copolymer, In some cases, a photosensitive resin composition is prepared at once from a radical polymerizable compound, a photopolymerization initiator, and the like.

In the above photosensitive resin composition, the radical polymerizable compound is capable of curing reaction by photopolymerization reaction. For example, a radical polymerizable oligomer in the form of an oligomer (low polymer) or a monomer (single amount) The radically polymerizable monomer which is in the form of the (body) is preferably used. Examples of the radical polymerizable oligomer include one or more of unsaturated polyester, epoxy acrylate, urethane acrylate, polyester acrylate, an acrylic polymer having a double bond in a side chain, and the like. Examples of the radical polymerizable monomer include aromatic vinyl monomers such as styrene, α-methylstyrene, α-chlorostyrene, vinyltoluene, divinylbenzene, diallyl phthalate, and diallylbenzenephosphonate; vinyl such as vinyl acetate and vinyl adipate. Ester monomer; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, β-hydroxyethyl (meth) acrylate, (2-oxo-1,3-dioxolan-4-yl) -methyl (meth) (Meth) acrylic monomers such as acrylate; (di) ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate (Meth) acrylic monomers such as polyfunctional (meth) acrylates such as tri (meth) acrylate of tris (hydroxyethyl) isocyanurate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tris (hydroxyethyl) isocyanurate; One type or two or more types such as triallyl cyanurate may be mentioned. Among these, it is preferable to use polyfunctional (meth) acrylate from the viewpoint of exposure sensitivity and physical properties of the coating film after photocuring.

The amount of the radical polymerizable compound used is preferably 5 to 200 parts by weight with respect to 100 parts by weight of the total amount of the pigment and the copolymer. If the amount is less than 5 parts by weight, the curing power at the time of exposure may not be sufficient. If it exceeds 200 parts by weight, the effects of the other components may not be sufficiently exhibited. More preferably, it is 5-100 weight part, More preferably, it is 10-100 weight part.

The photopolymerization initiator is excited by actinic rays to generate radicals, and initiates polymerization of the radical polymerizable compound. For example, benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether, and alkyl ethers thereof Acetophenones such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone and 1,1-dichloroacetophenone; anthraquinones such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone and 1-chloroanthraquinone Thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone and 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; Benzophenones such as non; 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1; acylphosphine One or more of oxides and xanthones are suitable.

The amount of the photopolymerizable initiator used is preferably 0.01 to 50 parts by weight with respect to 100 parts by weight of the total amount of pigment and copolymer. If the amount is less than 0.01 parts by weight, sufficient exposure sensitivity may not be obtained, and the light irradiation time may be long. If it exceeds 50 parts by weight, the exposure sensitivity becomes excessive, and there is a possibility that good resolution cannot be obtained. There is also a risk of economic disadvantage. More preferably, it is 0.1-30 weight part, More preferably, it is 0.3-10 weight part.

As the photosensitive resin composition, a thermal polymerization initiator can be used as necessary. Examples of the thermal polymerization initiator include polymerization used in the method for producing a copolymer in the pigment dispersion composition. The thing similar to an initiator is mentioned. What is necessary is just to set suitably as content of a thermal-polymerization initiator in the range which does not impair the effect of this invention.

The photosensitive resin composition of the present invention may further include fillers such as aluminum hydroxide, talc, clay, barium sulfate, dyes, antifoaming agents, coupling agents, leveling agents, sensitizers, release agents as necessary. It may contain additives such as molds, lubricants, plasticizers, antioxidants, ultraviolet absorbers, flame retardants, polymerization inhibitors and thickeners. Further, it may contain a novolac type epoxy resin, a bisphenol type epoxy resin, an alicyclic epoxy resin, an epoxy resin such as triglycidyl isocyanurate, an epoxy curing agent such as dicyandiamide or an imidazole compound, or a dioxazoline compound. What is necessary is just to set these addition amounts suitably in the range which does not impair the effect of this invention.

The photosensitive resin composition of the present invention is useful as a photoresist material, and can be particularly suitably used for producing a color filter used for a liquid crystal display element, a solid-state imaging element or the like. In producing such a color filter, it is preferable to apply a pigment dispersion method. The pigment dispersion method is a method using a photosensitive resin composition containing a binder resin, a radical polymerizable compound, a photopolymerization initiator, a pigment, and the like, but because it uses a pigment, it is stable to light, heat, etc. Since the patterning is performed by the photolithography method, the positional accuracy is good, and the method is suitable for manufacturing a color filter for a large screen / high definition color display.

In the pigment dispersion method, it is preferable to use a photosensitive resin composition having photocurability for curing the coating film in the exposed portion and alkali solubility for alkali developing the coating film in the unexposed portion. In the present invention, in such a photosensitive resin composition, it is possible to exhibit good pigment dispersibility and to increase exposure sensitivity and coating film strength. If the dispersibility of the pigment is not sufficient, it will cause agglomeration over time, impairing the coating properties, or causing an increase in viscosity, and at the same time when producing a color filter using such a resin composition However, characteristics such as exposure sensitivity, alkali developability, color purity, dimensional accuracy, etc. are not sufficient, and the display contrast ratio is deteriorated due to the depolarizing action. Conventionally, in general, pigments are not sufficiently dispersible or miscible with organic solvents, polymer compounds, etc., and the binder resin that is the main component of the photosensitive resin composition is also usually not sufficient in the dispersion medium for pigments. The photosensitive resin composition of the present invention can sufficiently satisfy the characteristics required for producing a color filter.

The color filter is composed of at least three primary color (RGB) fine pixels, a resin black matrix that separates them, a protective film, a columnar spacer, and the like. Among these structural members, it is preferable to use for three primary color (RGB) pixels and a resin black matrix.

For example, in the case of forming three primary color (RGB) pixels, the constituent members of the color filter using the photosensitive resin composition of the present invention are pigments of the three primary colors of red, green, and blue, and a resin black matrix. When forming, it can form by performing the process of following (1)-(3) in order using the photosensitive resin composition of this invention which contained the black pigment, respectively.
(1) The photosensitive resin composition of the present invention is coated on a substrate such as glass, preferably non-alkali glass, by a method such as a spin coating method, a coater method, or a spray method, and then dried to prepare a coating film. . As a coating method, a spin coating method or a coater method is preferable.
In the drying conditions, the temperature is preferably room temperature to 120 ° C. More preferably, the temperature is 60 ° C to 100 ° C. The drying time is preferably 10 seconds to 60 minutes. More preferably, it is 30 seconds to 10 minutes. Furthermore, it is preferable to heat and dry under normal pressure or vacuum.

(2) Thereafter, a photomask (patterning film) provided with an opening corresponding to a desired cross-sectional shape is placed on the coating film prepared in (1) in a contact state or a non-contact state, and irradiated with light. Harden. The light is preferably visible light, radiation such as ultraviolet rays, X-rays or electron beams. More preferably, it is ultraviolet rays. Note that a high-pressure mercury lamp is preferably used as the ultraviolet ray source.

(3) After light irradiation, development is performed with a solvent, water, an alkaline aqueous solution, or the like. Among these, it is preferable to use an alkaline aqueous solution because it can carry out highly sensitive development with little burden on the environment. As the alkali component, for example, potassium hydroxide, sodium hydroxide, sodium carbonate and the like are preferable. The alkali concentration is preferably 0.01 to 5% by mass. If it is less than 0.01% by mass, the photosensitive resin composition may not have sufficient solubility. If it exceeds 5% by mass, the surface of the coating film may be whitened during development. More preferably, it is 0.05-3 mass%, More preferably, it is 0.1-1 mass%. Further, a surfactant may be further added to the alkaline aqueous solution.
Since the coating film formed from the photosensitive resin composition of the present invention is excellent in tack-free properties even before exposure, it can be easily peeled even when a photomask is placed in contact. The pattern can be reproduced accurately.

In the case of forming a color filter constituent member, after the steps (1) to (3), heating is further performed (post-bake) to advance the curing, and the remaining solvent is completely removed. Is preferred. Thereby, the radically polymerizable double bond in the photosensitive resin composition that has not been cured by exposure can be sufficiently cured to form a very strong crosslinked body, and the coating film strength can be further improved. . The curing temperature during post-baking is preferably 120 to 300 ° C. If it is lower than 120 ° C., curing cannot proceed sufficiently and the coating film strength may not be sufficiently improved. If it is higher than 300 ° C., the smoothness of the coating film may not be sufficient due to thermal decomposition. More preferably, it is 150-250 degreeC, More preferably, it is 180-230 degreeC. Note that the post-baking may be performed after development in forming each member, or may be performed after all the members are formed.

In the color filter, the resin black matrix is first formed on the substrate by the formation method of each constituent member as described above, then each of the R, G, and B pixels is sequentially formed. In the case where a protective film for protecting the pixel is formed and the color filter is a color filter for liquid crystal, a columnar spacer can be formed as necessary. In addition, the said protective film can be formed by performing the said (1)-(3) process using the thermosetting resin and photocurable resin which do not contain a pigment, for example. In addition, the columnar spacer is formed by, for example, applying a photocurable resin not containing a pigment on the surface on which the spacer is to be formed to a thickness that makes the height of the desired spacer, and the steps (1) to (3) Can be formed. A method for manufacturing a color filter in this manner is also one of the preferred embodiments of the present invention.

Since the pigment dispersion composition of the present invention has the above-described configuration, it has excellent pigment dispersibility, can stably disperse the pigment, and does not deteriorate various properties such as developability due to the influence of the dispersant. Thus, since it can exhibit excellent alkali solubility and photocurability, it can be suitably used for a photosensitive resin composition for color filters and the like. In the case of use for a color filter, the dispersant can be eliminated or minimized, and the resist characteristics such as exposure sensitivity and coating strength can be improved.

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

Example 1-1
A reaction vessel equipped with a thermometer, a stirrer, a gas introduction tube, a cooling tube and a dropping vessel introduction port was charged with 700 g of propylene glycol monomethyl ether acetate (PGMEA), purged with nitrogen, and then heated to 90 ° C.
On the other hand, 6 g of 1-vinylimidazole, 62.1 g of methacrylic acid (MAA), 159.9 g of benzyl methacrylate (BzMA), 72 g of methyl methacrylate (MMA) and dimethyl-2,2′azobis (2 -Methyl propionate) (manufactured by Wako Pure Chemical Industries, "V601") was prepared by stirring and mixing.
After the temperature of the reaction vessel reached 90 ° C., dropping was started over 3 hours from the dropping vessel while maintaining the same temperature, and polymerization was performed. After maintaining the temperature at 90 ° C. for 30 minutes after completion of the dropping, the temperature was raised to 110 ° C. and aging was performed for 3 hours.

Thereafter, the nitrogen in the gas introduction tube was changed to an oxygen / nitrogen mixed gas (oxygen / nitrogen = 5/95 vol%), and 2,2′-methylenebis (4-methyl-6-tert-butylphenol) (Kawaguchi Chemical Co., Ltd.) was used as an inhibitor. Manufactured, “ANTAGE w-400”) 0.5 g and triethylamine (TEA) 1 g as a catalyst, and after stirring and mixing, 49.1 g of glycidyl methacrylate (GMA) was added as an addition compound, and the temperature was raised to 110 ° C. After 8 hours, the reaction was terminated when the amount of residual GMA by GC (gas chromatography) analysis was 0.1% by mass or less, and the side chain had a radical polymerizable double bond. A polymer solution of the acid group-containing copolymer was obtained. When the obtained polymer solution was analyzed as follows, the weight average molecular weight was 5000, the acid value was 77 mgKOH / g, the resin solid content was 28% by mass, and the radical polymerizable double bond amount was 0.99 mmol / g.

(Weight average molecular weight)
It was measured in terms of polystyrene by gel permeation chromatography (GPC: manufactured by Showa Denko KK, “Shodex GPC System-21H” was used).
(Acid value)
80 ml of acetone and 10 ml of water are added to 0.5 to 1 g of the polymer solution and stirred to dissolve uniformly, and a 0.1 mol / L KOH aqueous solution is used as a titrant to prepare an automatic titrator (Hiranuma Sangyo Co., Ltd., “COM-555”). )), And the acid value of the solution was measured.
On the other hand, a solution obtained by adding 2 ml of acetone to 1.0 g of a polymer solution was naturally dried at room temperature, further dried under reduced pressure (160 ° C./5 mmHg) for 5 hours, and then allowed to cool in a desiccator, and the mass was measured. .
Then, the acid value of the polymer was calculated from the acid value of the solution and the resin solid content of the solution.

(Radically polymerizable double bond amount)
The solvent was removed from the polymer solution by repeating the operation of adding 2 ml of acetone to 1.5 g of the polymer solution, allowing it to dry naturally at room temperature, and then drying under reduced pressure (70 ° C./5 mmHg) for 1 hour three times.
200 mg of the sample obtained as described above, 30-40 mmHg of chloroform as an internal standard substance, and about 3 g of dimethyl sulfoxide-d6 as an NMR solvent are weighed into a screw tube, shaken and dissolved well, and an NMR apparatus (Varian) Manufactured by “GEMINI2000”). From the integral ratio of the C = C peak (δ 5.6 to 6.2, 2H) and the chloroform peak (δ 8.3, 1H), the mass of the polymer, and the mass of chloroform in the obtained chart, the C per 1 g of the polymer = C amount (mmol / g) was calculated.

Example 1-2
A reaction vessel equipped with a thermometer, a stirrer, a gas introduction tube, a cooling tube and a dropping vessel introduction port was charged with 700 g of propylene glycol monomethyl ether acetate (PGMEA), purged with nitrogen, and then heated to 90 ° C.
On the other hand, 90 g of N-vinylcarbazole, 62.1 g of methacrylic acid (MAA), 75.9 g of benzyl methacrylate (BzMA), 72 g of methyl methacrylate (MMA) and dimethyl-2,2′azobis (2 -Methyl propionate) (manufactured by Wako Pure Chemical Industries, "V601") was prepared by stirring and mixing.
After the temperature of the reaction vessel reached 90 ° C., dropping was started over 3 hours from the dropping vessel while maintaining the same temperature, and polymerization was performed. After maintaining the temperature at 90 ° C. for 30 minutes after completion of the dropping, the temperature was raised to 110 ° C. and aging was performed for 3 hours.

Thereafter, the nitrogen in the gas introduction tube was changed to an oxygen / nitrogen mixed gas (oxygen / nitrogen = 5/95 vol%), and 2,2′-methylenebis (4-methyl-6-tert-butylphenol) (Kawaguchi Chemical Co., Ltd.) was used as an inhibitor. Manufactured, “ANTAGE w-400”) 0.5 g and triethylamine (TEA) 1 g as a catalyst, and after stirring and mixing, 49.1 g of glycidyl methacrylate (GMA) was added as an addition compound, and the temperature was raised to 110 ° C. After 8 hours, the reaction was terminated when the amount of residual GMA by GC analysis was 0.1% by mass or less, and the acid group-containing copolymer having a radically polymerizable double bond in the side chain. A coalesced polymer solution was obtained. The obtained polymer solution was analyzed in the same manner as in Example 1-1. The weight average molecular weight was 15000, the acid value was 70 mgKOH / g, the resin solid content was 30% by mass, and the radical polymerizable double bond amount was 0.99 mmol / g. Met.

Example 1-3
A reaction vessel equipped with a thermometer, a stirrer, a gas introduction tube, a cooling tube and a dropping vessel introduction port was charged with 700 g of propylene glycol monomethyl ether acetate (PGMEA), purged with nitrogen, and then heated to 90 ° C.
On the other hand, as a dropping tank, 15 g of 4-vinylpyridine, 62.1 g of methacrylic acid (MAA), 150.9 g of benzyl methacrylate (BzMA), 72 g of methyl methacrylate (MMA) and dimethyl-2,2′azobis (2 -Methyl propionate) (manufactured by Wako Pure Chemical Industries, "V601") was prepared by stirring and mixing.
After the temperature of the reaction vessel reached 90 ° C., dropping was started over 3 hours from the dropping vessel while maintaining the same temperature, and polymerization was performed. After maintaining the temperature at 90 ° C. for 30 minutes after completion of the dropping, the temperature was raised to 110 ° C. and aging was performed for 3 hours.

Thereafter, the nitrogen in the gas introduction tube was changed to an oxygen / nitrogen mixed gas (oxygen / nitrogen = 5/95 vol%), and 2,2′-methylenebis (4-methyl-6-tert-butylphenol) (Kawaguchi Chemical Co., Ltd.) was used as an inhibitor. Manufactured, “ANTAGE w-400”) 0.5 g and triethylamine (TEA) 1 g as a catalyst, and after stirring and mixing, 49.1 g of glycidyl methacrylate (GMA) was added as an addition compound, and the temperature was raised to 110 ° C. After 8 hours, the reaction was terminated when the amount of residual GMA by GC analysis was 0.1% by mass or less, and the acid group-containing copolymer having a radically polymerizable double bond in the side chain. A coalesced polymer solution was obtained. The obtained polymer solution was analyzed in the same manner as in Example 1-1. The weight average molecular weight was 15000, the acid value was 70 mgKOH / g, the resin solid content was 30% by mass, and the radical polymerizable double bond amount was 0.99 mmol / g. Met.

Example 1-4
664 g of propylene glycol monomethyl ether acetate (PGMEA) was charged into a reaction tank equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe, and a dripping tank introduction port, and after replacing with nitrogen, heated to 90 ° C. did.
On the other hand, 6 g of 1-vinylimidazole, 62.1 g of methacrylic acid (MAA), 134.1 g of benzyl methacrylate (BzMA), 72 g of methyl methacrylate (MMA), methoxydiethylene glycol methacrylate (Shin Nakamura) as a dropping tank (A) “NK ester M-20G” manufactured by Kagaku Kogyo Co., Ltd.) 25.8 g and t-butyl peroxy-2-ethylhexanoate (PBO; “Perbutyl O” manufactured by Nippon Oil & Fats) 6 g were mixed with stirring. (B) was prepared by stirring and mixing 16 g of n-dodecanethiol (n-DM) and 36 g of propylene glycol monomethyl ether acetate (PGMEA) in a beaker.
After the temperature of the reaction tank reached 90 ° C., dropping was started from the dropping tank (A) and the dropping tank (B), and polymerization was started. The dropwise addition was performed over 3 hours while maintaining 90 ° C. After maintaining the temperature at 90 ° C. for 30 minutes after completion of the dropping, the temperature was raised to 110 ° C. and aging was performed for 3 hours.

Thereafter, the nitrogen in the gas introduction tube was changed to an oxygen / nitrogen mixed gas (oxygen / nitrogen = 5/95 vol%), and 2,2′-methylenebis (4-methyl-6-tert-butylphenol) (Kawaguchi Chemical Co., Ltd.) was used as an inhibitor. (“Antage w-400”) 0.5 g, triethylamine (TEA) 1 g was added as a catalyst, and after stirring and mixing, 48.6 g of glycidyl methacrylate (GMA) was added as an addition compound, and the temperature was raised to 110 ° C. After 8 hours, the reaction was terminated when the residual GMA amount by GC analysis was 0.1% by mass or less after 8 hours, and the polymer solution of an acid group-containing polymer having a radically polymerizable double bond in the side chain Got. When the obtained polymer solution was analyzed as follows, the weight average molecular weight was 5000, the acid value was 71 mgKOH / g, the resin solid content was 30% by mass, and the radical polymerizable double bond amount was 0.96 mmol / g.

Comparative Example 1-1
Propylene glycol monomethyl ether acetate (PGMEA) 609.8 g was charged into a reaction vessel equipped with a thermometer, a stirrer, a gas introduction tube, a cooling tube, and a dripping vessel introduction port, and after replacing with nitrogen, heated to 90 ° C. did.
On the other hand, as a dropping tank, 68 g of methacrylic acid (MAA), 175 g of benzyl methacrylate (BzMA), 85.4 g of methyl methacrylate (MMA) and dimethyl-2,2 ′ azobis (2-methylpropionate) (sum) A product prepared by stirring and mixing 16.4 g of “V601” manufactured by Kojun Pharmaceutical Co., Ltd. was prepared.
After the temperature of the reaction vessel reached 90 ° C., dropping was started over 3 hours from the dropping vessel while maintaining the same temperature, and polymerization was performed. After maintaining the temperature at 90 ° C. for 30 minutes after completion of the dropping, the temperature was raised to 110 ° C. and aging was performed for 3 hours.

Thereafter, the nitrogen in the gas introduction tube was changed to an oxygen / nitrogen mixed gas (oxygen / nitrogen = 5/95 vol%), and 2,2′-methylenebis (4-methyl-6-tert-butylphenol) (Kawaguchi Chemical Co., Ltd.) was used as an inhibitor. Manufactured, “ANTAGE w-400”) 0.6 g, and 1.1 g of triethylamine (TEA) as a catalyst were added and stirred and mixed, and then 54.2 g of glycidyl methacrylate (GMA) was added as an addition compound, and 110 ° C. After 8 hours, the reaction was terminated when the residual GMA amount by GC analysis was 0.1% by mass or less, and an acid group having a radically polymerizable double bond in the side chain was contained. A polymer solution of the copolymer was obtained. The obtained polymer solution was analyzed in the same manner as in Example 1-1. As a result, the weight average molecular weight was 14500, the acid value was 70 mgKOH / g, the resin solid content was 35% by mass, and the radical polymerizable double bond amount was 0.99 mmol / g. Met.

Example 2-1
The polymer solution obtained in Example 1 was added to 3.3 parts by weight of resin solids, 16.3 parts by weight of carbon black (“Special Black 250”, manufactured by Degussa), and further to 80.4 propylene glycol monomethyl ether acetate. A black pigment dispersion was obtained by adding parts by weight. And the obtained black pigment dispersion liquid was evaluated as follows. The results are shown in Table 1.

<Dispersibility and storage stability>
To the black pigment dispersion obtained in Example 2-1, zirconia beads (1.0 mmΦ) having a mass ratio of 2 times were added and dispersed for 4 hours using a paint shaker. A thixotropic test for measuring viscosity and a particle size measurement were performed to evaluate dispersibility. The viscosity measurement in the thixotropic test was carried out using a viscometer (“TV-20 viscometer cone plate type” manufactured by Tokimec Co., Ltd.) and rotor No. The viscosity after 1 minute of measurement time was measured at 1 ° 34 ′ × R24. Further, after leaving the obtained black pigment dispersion at 80 ° C. for 3 days, a thixotropic test was similarly conducted to evaluate the storage stability.
The particle diameter was measured by a dynamic light scattering method using a light scattering photometer (manufactured by Otsuka Electronics Co., Ltd., “Dynamic Light Scattering Photometer DLS-700”), and the particle diameter was calculated by a histogram method analysis. Further, the particle size was measured in the same manner after the obtained black pigment dispersion was allowed to stand at 80 ° C. for 3 days.

Examples 2-2, 2-3, 2-4 and Comparative Example 2-1
A black pigment dispersion was carried out in the same manner as in Example 2-1, except that the polymer obtained in Example 1 or Comparative Example shown in Table 1 was used instead of the polymer obtained in Example 1-1. A liquid was obtained. And evaluation similar to Example 2-1 was performed. The results are shown in Table 1.

Example 3-1.
2.7 parts by weight of trimethylolpropane triacrylate, 0.4 part by weight of 2,4-diethylthioxanthone and 2-methyl-morpholino (4-methylphenyl) propane-1- based on 100 parts by weight of the black pigment dispersion 0.5 parts by weight of ON was added and dissolved by stirring with a stirrer, followed by filtration through a 10 μm membrane filter to obtain a black photosensitive resin composition. And the obtained black photosensitive resin composition was evaluated as follows. The results are shown in Table 2.

<Resist characteristics>
The black photosensitive resin composition was applied on a 5 cm × 5 cm glass plate by spin coating so as to have a coating film of 1 μm, and then pre-baked at 100 ° C. for 5 minutes to form a dry coating film. Next, the dried coating film is irradiated with ultraviolet rays through an ultrahigh pressure mercury lamp through a predetermined photomask, then alkali-developed with a 0.1% by mass aqueous potassium hydroxide solution, and further post-baked at 180 ° C. for 40 minutes to be cured. A sample was prepared.

The following evaluation was performed in the above sample preparation.
(Applicability) The coating unevenness of the resist coating after coating and drying was evaluated by visual observation. The case where a uniform coating film was obtained was marked with ◯, and the case where coating unevenness was observed was marked with x.
(Exposure sensitivity) Sensitivity was defined as the exposure amount (appropriate exposure amount) required to form a pattern for forming a line and space with a width of 20 μm according to the mask dimensions. It can be said that the smaller the appropriate exposure amount, the better the exposure sensitivity.
(Developability (development time)) When exposure is carried out with an appropriate exposure amount using a pattern forming a 20 μ width line and space, the time required for development is 30 seconds or less, ○, 60 seconds or less △, when exceeding 60 seconds was marked with ×.

(Resolving power) The resolving power was evaluated with the minimum resist pattern size capable of forming an image. That is, the case where the reproducible resist pattern is a line and space having a width of 10 μm or less is indicated by “◯”, the case of a line and space having a width of 15 μm or less is indicated by Δ, and the case of a line and space having a width of 16 μm or more is indicated by “X”.
(Adhesion) The cured coating film (resist pattern pixel part) of the obtained sample was cut into 1 mm square scratches in a grid pattern with a cutter, and an adhesive tape (“Cello Tape (registered trademark)”) was placed on it. When it peeled after making it adhere | attach, it was set as (circle) and the case where peeling was recognized when the peeling of a cured coating film was not recognized at all.
(Light-shielding property) The optical density (OD value) of the cured coating film (resist pattern pixel portion) of the obtained sample was measured with a Macbeth densitometer ("TR-927" manufactured by Kolmorgun Co., Ltd.). The OD value is a value representing the degree to which a substance absorbs light, and it can be said that the higher the OD value, the higher the color material concentration.

Examples 3-2, 3-3, 3-4 and Comparative Example 3-1.
Instead of the black pigment dispersion obtained in Example 2-1, the same procedure as in Example 3-1 was used except that the black pigment dispersion obtained in Examples or Comparative Examples shown in Table 1 was used. A black photosensitive resin composition was obtained. And evaluation similar to Example 3-1 was performed. The results are shown in Table 2.

Example 4-1
The polymer solution obtained in Example 1-1 was 15 parts by weight in terms of resin solids, C.I. I. Pigment Green 36, 10 parts by weight; I. Pigment Yellow 138 was added to 2 parts by weight, and further 75 parts by weight of propylene glycol monomethyl ether acetate was added to obtain a green pigment dispersion. And the obtained green pigment dispersion liquid was evaluated as follows. The results are shown in Table 3.

<Dispersibility and storage stability>
Dispersibility and storage stability were evaluated in the same manner except that the pigment was changed from a black pigment to a green pigment in Example 2-1.

Examples 4-2, 4-3, 4-4 and Comparative Example 4-1
Instead of the green pigment dispersion obtained in Example 4-1, the example shown in Table 1 or the polymer solution obtained in the comparative example was used, in the same manner as in Example 4-1, A green pigment dispersion was obtained. And evaluation similar to Example 4-1 was performed. The results are shown in Table 3.

Example 5-1
With respect to 100 parts by weight of the green pigment dispersion, 2.7 parts by weight of trimethylol propant acrylate, 0.4 parts by weight of 2,4-dimethylthioxanthone, and 2-methyl-2-morpholino (4-thiomethylphenyl) ) Add 0.5 parts by weight of propan-1-one and further propylene glycol monomethyl ether acetate to a solid content concentration of 12% by mass, stir with a stirrer and dissolve, then with a 10 μm membrane filter. Filtration gave a green photosensitive resin composition. And the obtained green photosensitive resin composition was evaluated as follows. The results are shown in Table 4.

<Resist characteristics>
Using the green photosensitive resin composition, a sample was prepared in the same manner as in the evaluation of resist characteristics in Example 3-1, and (Applicability), (Exposure sensitivity), (Developability), (Adhesion) ) Was evaluated.

Further, as a resist characteristic of the green photosensitive resin composition, (contrast) was evaluated by the following method.
(Contrast) The effect coating film (resist pattern pixel part) of the obtained sample is placed between two deflection plates. The luminance when the deflection axis is parallel (parallel luminance) and the luminance when the deflection axis is vertical (vertical luminance) ) And the ratio (parallel luminance / vertical luminance) was taken as contrast.

Examples 5-2, 5-3, 5-4 and Comparative Example 5-1.
Instead of the green photosensitive resin composition obtained in Example 5-1, the same procedure as in Example 5-1 was used except that the green dispersion obtained in the examples shown in Table 3 or the comparative examples was used. A green pigment photosensitive resin composition was obtained. And evaluation similar to Example 5-1 was performed. The results are shown in Table 4.

Claims (7)

A pigment dispersion composition comprising: a copolymer having a nitrogen-containing monomer unit having a ring structure composed only of nitrogen atoms and carbon atoms; a monomer having a monomer unit having an acid group; and a pigment. . A pigment dispersion composition comprising: a copolymer having a nitrogen-containing monomer unit having a heteroaromatic ring structure essentially containing a nitrogen atom and a monomer unit having an acid group; and a pigment. The pigment dispersion composition according to claim 1 or 2, wherein the copolymer has a nitrogen-containing monomer unit content of 0.1 to 60% by mass and an acid value of 30 to 200. . The pigment dispersion according to claim 1, 2 or 3, wherein the nitrogen-containing monomer unit is formed from at least one monomer selected from the group consisting of vinylimidazole, vinylcarbazole and vinylpyridine. Composition. The pigment dispersion composition according to claim 1, 2, 3, or 4, wherein the copolymer has a radical polymerizable double bond in a side chain. A photosensitive resin composition comprising the pigment dispersion composition according to claim 1, 2, 3, 4, or 5, and a radical polymerizable compound and a photopolymerizable initiator. An acid group containing a nitrogen-containing monomer unit having a heteroaromatic ring structure in which a nitrogen atom is essential and a monomer unit having an acid group, and having a polymerizable double bond in the side chain Copolymer.