JP2957028B2 - Photocurable coloring composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coloring composition which is cured by light irradiation. This coloring composition is a coloring composition useful for producing, for example, a color filter for a liquid crystal display device and a color separation filter for printing.

[0002]

2. Description of the Related Art A resin which forms a film by being cured by light irradiation is known as a photocurable resin. After the photocurable resin is applied, a mask is placed thereon, and the mask is provided with a portion that transmits light and a portion that does not transmit light in advance, and a portion that does not transmit light after being irradiated with light. It is used to remove the uncured resin remaining in the resin and form a resin film in a desired shape. As a film, a colorless, transparent and rigid one is desirable, and a photocurable resin that forms such a film is required.

[0003] It is known to produce colored images using photocurable resins. Japanese Patent Application Laid-Open No. 60-129738 proposes that a polyvinyl acetal compound obtained by acetalizing polyvinyl alcohol with an aldehyde having a styrylpyridinium group is used as a photocurable resin to form a colored image. The proposal is
A fine powder of a pigment is dispersed in a polyvinyl acetal compound to form a paint. The paint is applied, the above-described mask is placed on the applied surface, the light-irradiated portion is cured, and the uncured portion is treated with water. And leave a hardened part afterwards.

[0004] This method has a disadvantage that it is difficult to uniformly disperse the pigment in polyvinyl acetal having a styrylpyridinium group, and thus it is difficult to prepare a paint itself. Further, since this polymer has a property close to that of polyvinyl alcohol, when the coating film of this paint is treated at a high temperature, it tends to peel off from the substrate.

[0005] Also, Japanese Patent Application Laid-Open No. 64-35417 discloses that
It has been proposed to use a composition comprising a photosensitive resin having an acryloyl group and a pigment as a paint to form a colored image. This proposal is to make a paint by adding a polymerization initiator such as anthraquinone and a fine powder of pigment to a photosensitive resin such as triethylene glycol diacrylate, and put a mask on the coating surface of this paint, and shine light. Irradiate to partially cure the resin, remove the uncured portion with a solvent and develop,
They make colored images.

[0006] This proposal is harmful to the health of workers, in some cases a fire hazard, and requires special attention to waste liquid treatment, since organic solvents must be used to make the paint. Had the disadvantage of having to do so. Further, the photosensitive resin having an acryloyl group,
In general, the polymerization reaction is easily inhibited by oxygen, so it is necessary to take special measures such as covering the coated surface with a polyvinyl alcohol film in order to avoid the influence of oxygen when irradiating light. Not so.

In addition, JP-A-58-199342 proposes to use a special acrylic copolymer as a photocurable resin. The special copolymer has the general formula

[0008]

Embedded image And a monomer represented by

[0009]

Embedded image Or

[0010]

Embedded image Is a binary copolymer obtained by copolymerizing a monomer represented by the following formula: This proposal teaches adding a diazo compound or an azide compound to this binary copolymer to obtain a photocurable resin. Here, X is O or NH, Y is an acid group, R ₁ , R ₂
Is H, CH ₃ or C ₂ H ₅ , n is an integer of 1 to ₃ , R ₃ is H or CH ₃ , R ₄ is an alkylene group having 2 or 3 C,
R ₅ , R ₆ and R ₇ represent H or an alkyl group having 1 to 4 carbon atoms.

[0011] In this proposal, in order to color the resin thus obtained, it must be dyed with a special dye later.
In order to form a color filter, it is necessary to dye deeply. However, if it is desired to dye a coating film having a thickness of about 2 microns to a high density, for example, an optical density of 2 or more, the following equation (5) or (6) is used. The concentration of the compound must be considerably increased, but this has the disadvantage that the polymer itself discolors due to thermal decomposition at high temperatures, and the dye is discolored by the action of decomposition products.

Japanese Patent Application Laid-Open No. 1-200353 discloses that
A photocurable colored composition comprising a polymer solution having a tetravalent covalent nitrogen, a dye compound, and a radiation-sensitive crosslinking agent is disclosed. In this case, the polymer having a tetravalent covalent nitrogen is represented by the general formula

[0013]

Embedded image It is said to have been obtained by polymerization of the monomer represented by Here, R ₈ is hydrogen or a methyl group, and R ₉ is 2
The valence organic group, Z, is an oxygen atom or an imino group.
Therefore, the monomer of the formula (7) is almost the same as the compound of the above (formula 6).

The polymer obtained from the monomer of the formula (7) taught by JP-A-1-200353 is difficult to disperse a dye compound, that is, a pigment, has poor adhesion to a glass substrate, and has a particularly high temperature. When heated to 200 ° C. or more, there was a disadvantage that the material became brown.

Japanese Patent Application Laid-Open No. 1-200353 discloses that a compound of the formula (7) is copolymerized with another unsaturated compound, conscious of the fact that a polymer of the compound of the formula (7) has difficulty in solubility. Mention that you may let them. In this case, copolymerization partners include unsaturated carboxylic acids such as acrylic acid and methacrylic acid, esters such as methyl acrylate and ethyl methacrylate, vinyl aromatic compounds such as styrene and vinyl naphthalene, and N-vinylpyrrolidone. Examples include a wide range of compounds such as vinyl nitrogen-containing compounds such as 4-vinylpyridine and the like. One of them may be used or two or more of them may be mixed and copolymerized. ing. However, what was copolymerized,
No change in properties other than solubility has been confirmed.

[0016]

SUMMARY OF THE INVENTION The present invention has been made to provide a photocurable colored composition which eliminates the above-mentioned disadvantages of the conventional method. That is, both the photosensitive solution and the developing solution are photocurable resins in which water can be used as a solvent, and it is easy to disperse the fine powder of the pigment therein, and can be colored deeply with curing. The object is to provide a photocurable composition which adheres firmly to a glass substrate or the like and forms a transparent thin insoluble film.

[0017]

The gist of the present invention is to use a special copolymer as a photocurable resin. Further, the present invention provides that when the copolymer is cured by light irradiation, a photoreactivity imparting agent such as a water-soluble diazo resin or a water-soluble polyfunctional aromatic azide compound is present as a curing agent. It is the main point. In addition, the present invention
The fact that fine pigment powders are contained in a dispersed state therein is also essential. Here, the special copolymer is

[0018]

Embedded image

[0019]

Embedded image

[0020]

It is a water-soluble copolymer produced by copolymerization of three monomers represented by the following formula. Wherein R ₁ , R ₂ , R ₄
Is hydrogen or a methyl group; R ₃ is hydrogen or a carboxyl group; and A is —CH ₂ —CH ₂ — or —C
H ₂ —CH ₂ —CH ₂ —, and B is

[0021]

Embedded image Here, R ₅ represents a methyl group or an ethyl group, and X represents a halogen or other anion group.

The above-mentioned copolymers are unique in that they are water-soluble. More specifically, a monomer having a hydroxyl group (formula 1) and a monomer having a carboxyl group (formula 3)
In general, a binary copolymer obtained by copolymerizing a monomer of the formula (1) is generally insoluble in water, but a small amount of an amino group or a quaternary ammonium group represented by the formula (2) is added thereto. Upon introduction, the resulting terpolymer was found to be water soluble. The present invention has been completed based on such confirmation.

[0023]

SUMMARY OF THE INVENTION The present invention relates to a water-soluble copolymer produced by copolymerization of the three types of monomers represented by the above-mentioned (formula 1), (formula 2) and (formula 3). The present invention relates to a coloring composition obtained by adding a pigment and a photoreactivity imparting agent.

[0024]

DESCRIPTION OF THE REQUIREMENTS The coloring composition according to the present invention contains a water-soluble copolymer produced by copolymerization of three types of monomers of the formulas (1), (2) and (3). In. Among them, the monomer represented by (Formula 1) is, for example, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.

The monomer represented by the formula (2) is a compound containing an amino group or a quaternary ammonium group substituted with an alkyl group. Among them, the compound containing an amino group is, for example, dimethylaminoethyl acrylamide, diethylaminoethyl acrylamide, dimethylaminoethyl methacrylamide, diethylaminoethyl methacrylamide, dimethylaminopropyl acrylamide, diethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide, diethylaminopropyl methacryl Amides. Compounds containing an ammonium group include, for example, acrylamidoethyltrimethylammonium chloride, acrylamidoethyltriethylammonium chloride, acrylamidopropyltrimethylammonium chloride, acrylamidopropyltriethylammonium chloride, methacrylamidoethyltrimethylammonium chloride,
Methacrylamidoethyltriethylammonium chloride, methacrylamidopropyltrimethylammonium chloride, and methacrylamidopropyltriethylammonium chloride.

The monomers represented by the formula (3) are acrylic acid, methacrylic acid, maleic acid and fumaric acid.

In order to copolymerize the monomers represented by the above (formula 1), (formula 2) and (formula 3), these monomers are dissolved in an appropriate solvent and polymerized. As a solvent, an organic solvent such as methyl cellosolve or dimethylformamide can be used, but water is preferably used. A polymerization initiator is used for the copolymerization, and the polymerization initiator for the copolymerization in water is ammonium persulfate, 2,2′-azobis (N, N′-dimethyleneisobutylamidine) hydrochloride, 2, 2 '
-Azobis (2-amidinopropane) hydrochloride, 4,4'-azobis (4-cyanopentanoic acid), 2,2'-azobis {2-methyl-N [1,
1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide} and the like.

Preferred copolymerization ratios of the monomers represented by the formulas (1), (2) and (3) are as follows.
The monomer represented by the formula (1) preferably accounts for 60 to 90% by weight of the copolymer. The reason for this is that if the amount of the monomer of the formula (1) is less than 60% by weight, the water solubility, photocrosslinking property and adhesion to the substrate of the obtained copolymer are reduced, and conversely 90% by weight. %, The water solubility of the copolymer deteriorates.

The monomer represented by the formula (2) preferably accounts for 0.5 to 10% by weight, and particularly preferably 1 to 5% by weight, of the copolymer. The reason is that when the amount of the monomer of the formula (2) is less than 0.5% by weight, it becomes difficult to make the copolymer water-soluble,
Conversely, if the content is more than 10% by weight, the thermal stability of the obtained copolymer decreases.

The monomer represented by the formula (3) preferably accounts for 0.1 to 5% by weight of the copolymer, and more preferably 0.5 to 3% by weight. The reason for this is that if the amount of the monomer of the formula (3) is less than 0.1% by weight, it becomes difficult to disperse the pigment in the copolymer. This is because the water solubility of the coalescence decreases, and for example, after curing by irradiation with light, it is not easy to remove the uncured material with an aqueous acetic acid solution.

The above copolymer may contain a small amount of another monomer as an optional component. Other monomers are, for example, acrylamide, methacrylamide, N-vinylpyrrolidone, diacetone acrylamide, tetrahydrofurfuryl acrylate, glycerin monoacrylate, and the like.

It is desirable to use methacrylamide among the optional components. Methacrylamide is water-soluble by nature, but it has a moderate degree of hydrophobicity.
Even if the copolymer obtained by adding this is heat-treated at a high temperature,
This is because discoloration and coloring are less likely to occur, and rather, the degree of crosslinking is improved and the strength as a film is increased. The amount of methacrylamide added can be larger than the monomer represented by (Formula 2) or (Formula 3), and can be 0 to 20% by weight.

When the molecular weight of the copolymer is too small, when this is used as a color filter,
Resolution deteriorates. Conversely, if the molecular weight is too large,
After curing by irradiation with light, it becomes difficult to dissolve the uncured portion and remove it from the cured portion. Therefore, the copolymer is
Its molecular weight is 10,000 to 20 in weight average molecular weight.
It is suitably set to 0000.

In the present invention, any of organic pigments and inorganic pigments can be used. However, when it is used to make a color filter, it is preferable to use an organic pigment having a wide selection of the transmitted light spectrum. As the organic pigment, various pigments such as phthalocyanine, azo, perinone, anthraquinone, quinacridone, indanthrone, dioxazine, and thioindigo can be used.

The pigment is dispersed in the copolymer as a fine powder. As a fine powder, the size of the pigment particles looks turbid if they are larger than the wavelength of light of that color,
Preferably, the average particle size is less than 0.5 microns.
In order to disperse the pigment, it is preferable to previously disperse the pigment fine powder in an aqueous solution containing a dispersant, and to add and disperse the dispersion into an aqueous solution of a copolymer. A turbo mixer, a ball mill, an attritor, a bead mill, or the like is used to make a dispersion of the pigment fine powder. As the dispersant, a surfactant and a water-soluble polymer can be used.
However, it is necessary to use a nonionic or cationic surfactant. This is because the monomer represented by (Formula 2) is cationic. It is particularly preferable to use a nonionic one. Further, as the water-soluble polymer, it is preferable to use partially saponified polyvinyl acetate, polyvinyl alcohol partially introduced with a cationic group, or polyvinyl pyrrolidone.

The amount of the pigment to be added to the copolymer is 50 to 200 parts by weight based on 100 parts by weight of the copolymer. In general, if the amount of the pigment is too small, the degree of coloration is naturally insufficient.If the amount is too large, the photosensitivity is reduced, and the film forming ability is reduced due to the lack of the resin. It becomes difficult. However, the copolymer used in the present invention can form a fine image by increasing the additive amount of the pigment.

In the present invention, a water-soluble diazo resin or a water-soluble polyfunctional aromatic azide compound is used as a photoreactivity imparting agent for the copolymer. A diazo resin is a resin produced by adding and condensing formaldehyde to an aromatic diazonium compound. Examples of the aromatic diazonium compound include p-diazodiphenylaluminum and 2.5.
-Dimethoxy-4-p-tolylmercaptobenzenediazonium, 2.5-dimethoxy-4-morpholinobenzenediazonium and the like.

The polyfunctional aromatic azide compound is an aromatic compound having two or more azide groups in one molecule. For example, 4,4'-diazidostilbene-
Sodium 2,2'-disulfonate, 2,6-bis (4
-Azidobenzal) acetone-2-sulfonic acid, 2,
6-bis (4-azidobenzal) cyclohexanone-
2,2'-disulfonic acid, 2,6-bis (4-azidobenzal) acetone-2,2'-disulfonic acid and the like. These water-soluble diazo resins or water-soluble polyfunctional aromatic azide compounds are used in an amount of 5-30 parts per 100 parts by weight of the copolymer.
It is preferred to use parts by weight.

The composition according to the present invention is usually used as an aqueous solution. To this end, an aqueous dispersion of the pigment fine powder is added to the aqueous solution of the copolymer as described above and mixed well, and a photoreactivity imparting agent such as a water-soluble diazo resin or a polyfunctional aromatic azide compound is added and dissolved. Let it. The aqueous solution thus obtained can be easily applied to glass or other substrates by a spin coater or a roll coater.

[0040]

According to the present invention, (Equation 1) and (Equation 2)
And a copolymer consisting of the monomers of formula (3)
By using water as a solvent, adding a polymerization initiator thereto and heating, a copolymer can be easily produced. The copolymer thus produced has photocurability, can be obtained as an aqueous solution, and can easily disperse the fine powder pigment. Therefore, it can be used as it is as a photocurable paint. Therefore, in this case, there is no disadvantage or complexity due to the use of the organic solvent. Further, since the composition of the present invention is added with a photoreactivity imparting agent such as a water-soluble diazo resin or a polyfunctional aromatic azide compound, the photoreactivity imparting agent is exposed to light to cause the copolymer to react with the copolymer. It acts as a hardener and forms a strong film. In addition, the copolymer has a high affinity for pigments because it contains hydroxyl groups and has zwitterionic properties including carboxyl groups and substituted or unsubstituted amino groups or quaternary ammonium groups. Many pigments can be included, with which a densely colored film can be produced at once. Therefore, the film can be made thinner, and when used for ITO electrode processing, a clearer image can be given. Moreover,
Since this copolymer is amphoteric, it is easily dissolved in water, and water can be used to remove uncured resin, so that development is easy. Therefore, the composition of the present invention is suitable for producing a color filter of a liquid crystal display element and a color separation filter of printing as a photocurable coloring composition.

The advantages of the present invention will be specifically described below with reference to Examples and Comparative Examples. In the following, simply referring to parts or% means parts by weight or% by weight.

[0042]

Embodiment 1

[Preparation of Composition] The following monomer aqueous solution was added dropwise to the flask containing 150 parts of deionized water and 50 parts of acetic acid over 4 hours while thoroughly stirring at 85 ° C. while passing nitrogen gas through the flask. Acrylic acid 2 parts 2-Hydroxyethyl methacrylate 84 Dimethylaminopropyl methacrylamide 4 Methacrylamide 10 2,2'-Azobis (N, N'-dimethylene 1.2 isobutylamidine) hydrochloride (polymerization initiator) Deionized water 200 85 The mixture was copolymerized with stirring at 4 ° C. for further 4 hours to obtain an aqueous solution of the copolymer. An aqueous solution obtained by filtering this with a membrane filter having a pore diameter of 0.20 μm was used as a photocurable resin.

To make a separate pigment dispersion, the following formulation was made: Phthalocyanine-water mixed cake (pigment content 48%) 100 parts Surfactant (trade name Neugen EA-130T) 155 5% aqueous polyvinyl alcohol solution 300

The above composition was placed in a blender and stirred so that no large particles remained. It was transferred to an alumina pot filled with zirconia beads having a diameter of 1 mm, and crushed with a vibration mill. Further, the mixture was centrifuged at 12,000 rpm to remove coarse particles to prepare a pigment dispersion.

To 10 parts of the aqueous photocurable resin solution obtained above, 45 parts of the pigment dispersion and 30 parts of water were added.
Add 0.2 parts of a water-soluble diazo resin sold by Shinko Giken Co., Ltd. under the name of diazo resin D-13, mix well in a mixer, and then mix with a pore diameter of 0.8 μm.
m and filtered to give the composition of the present invention.

[0046]

[Test for use of composition] The above composition was placed on a glass plate for 2000 times.
Spin coating was performed at rpm, a photomask was overlaid, and an ultraviolet ray of 65 mJ / cm ² was irradiated from above using a super-high pressure mercury lamp. Then, when developed with 2% aqueous acetic acid, the line width was 10 μm.
m could be reproduced. The film thickness after drying was 0.4 μm.
The light transmittance at 460 nm was 70%. After heating the colored plate in an oven at 230 ° C. for 1 hour, the light transmittance was measured to be 68%. Therefore, this composition was suitable for obtaining such fine images.

[0047]

Embodiment 2

Preparation of the composition This example is the same as Example 1, except that the following monomer mixture was used to make the copolymer. The composition was made. Acrylic acid 1 part 2-Hydroxyethyl methacrylate 86 Dimethylaminopropylacrylamide 3 Methacrylamide 10

[0048]

Exposure and development were performed in exactly the same manner as in Example 1. As a result, a clear image was obtained as in Example 1.

[0049]

Comparative Example 1 This comparative example was carried out without using the carboxyl group-containing monomer represented by the formula (3) among the monomers used in the present invention. More specifically, an aqueous solution of a photocurable resin was prepared in exactly the same manner as in Example 1, except that the following monomer mixture was used to prepare the copolymer. 2-hydroxyethyl methacrylate 83 parts Dimethylaminopropyl methacrylamide 7 Methacrylamide 10 Polymerization initiator (same as in Example 1) 1.2 Acetic acid 50 Water 350

Using this aqueous resin solution and using the same pigments and the like used in Example 1, two types of compositions A and B corresponding to the present invention were prepared. A composition B composition Aqueous resin solution 10 parts 10 Pigment dispersion 45 11 Water 30-diazo resin 0.2 0.2

Composition A was spin-coated on a glass plate in the same manner as in Example 1, irradiated with ultraviolet rays, and developed. As a result, most of the composition flowed out, and the remaining part was porous and turbid. I was

On the other hand, when the composition B was spin-coated in the same manner, irradiated with ultraviolet rays, and developed, the resolution and the light transmittance were almost the same as those in Example 1, but the film obtained by drying was The thickness was 1.2 μm. The fact that the film thickness of this comparative example was larger than that of Example 1 made the image unclear.

After heating the colored plate in an oven at 230 ° C. for 1 hour, the light transmittance at 460 nm was measured. As a result, it was 60%, which was considerably discolored compared to 71% before heating. .

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03F 7/033 G03F 7/004 G03F 7/008 G03F 7/021

Claims (2)

(57) [Claims] 1. A 60 to 90 wt% of the general formula _{CH 2 = C-C-O} -CH 2 -CH 2 -OH ( Formula 1) | ‖ a monomer represented by R ₁ O, 0.5 10 wt% of the general formula _{CH 2 = C-C-NH} -a-B ( formula 2) | ‖ R ₂ and a monomer represented by O, 0.1 to 5 wt% of the general formula R ₃ - CH = C—C—OH (Formula 3) | ‖A powdery pigment and a photoreactivity imparting agent are added to a copolymer produced by copolymerization with a monomer represented by R ₄ O. A photocurable colored composition comprising: Here, R ₁ , R ₂ , and R ₄ are all hydrogen or a methyl group, R ₃ is hydrogen or a carboxyl group, and A is —CH ₂ —CH ₂ — or —CH ₂ —C
A group, B is -N = (R _{5) 2} or ^{_{-N + ≡ (R 5) 3}} X - - H 2 -CH 2 is a group. In this case, R ₅ represents a methyl group or an ethyl group, and X represents a halogen or another anion group. 2. The copolymer (formula 1), (formula 2),
2. A photocurable composition according to claim 1, wherein a copolymer obtained by adding and copolymerizing methacrylamide with the monomer represented by the formula (3) is used. Coloring composition.