JP2000327728A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new radiation-curable composition which has excellent pigment dispersibility, excellent compatibility with radiation-reactive compounds and excellent adhesivity to substrates, gives coating films having excellent water resistance and excellent alkali resistance, and can especially be applied to color filters and so on. SOLUTION: This curable composition comprises a radiation-curable graft copolymer that is produced from branch polymers having radiation-reactive polymerizing groups and carboxyl groups and a trunk polymer having radiation- reactive polymerizing groups and hydroxyl groups, and a compound which has one or more (meth)acryloyl groups in the molecule and a mol.wt. of 100 to 5,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a radiation-reactive curable composition. More specifically, the present invention relates to a radiation curable composition applicable to UV / electron beam curable ink, UV / electron beam curable paint / coating agent, UV curable adhesive, photoresist ink, dry film and the like. In particular, it is used as a dispersant and binder of a pigment for forming a color filter, and has a good dispersibility of the pigment, excellent adhesion to a substrate, excellent alkali developability and coating film hardness, and a pigment dispersed therein. It relates to a radiation-curable composition.

[0002] In the application of color filters, the steps of curing, alkali developing, and washing the radiation-curable composition are repeated in red, green, and blue colors, so that particularly severe water resistance and alkali resistance are required. Was inadequate. The curable composition of the present invention is particularly suitable for a color filter in terms of pigment dispersibility, radiation curability, water resistance of a coating film, alkali developability, and the like.

[0003]

2. Description of the Related Art A combination of an acrylic resin and a radiation-reactive compound has been conventionally known as an active energy ray-curable resin composition. Radiation-reactive compounds lack water resistance and flexibility but have excellent radiation curability, whereas acrylic resins have excellent water resistance and flexibility but lack radiation curability. To compensate for the lack of performance. A method of introducing a radiation-curable functional group into an acrylic resin has also been proposed and has been partially put into practical use. However, in the trend of lighter, thinner and more compact products in the industrial world, higher water resistance, flexibility and curability are required. Recently, a number of patents have been filed with a focus on graft polymer structures.

In dry film applications, see, for example,
3-32811, JP-A-2-84424, JP-A-2-84
-97516, JP-A-2-97517, JP-A-2-97
No. 103215, JP-A-2-153916 and JP-A-5-27432 have been filed, and a trunk polymer containing as a main component a polymer of a monomer selected from the group consisting of alkyl (meth) acrylate, acrylonitrile and styrene And a graft polymer comprising a polymer of a vinyl monomer having a hydroxyl group, an amino group, an alkylamino group, a carboxy group, vinylpyrrolidone or a derivative thereof (for example, a carboxyl group modified with glycidyl methacrylate). Has been proposed. However, the functional group such as a carboxyl group, a hydroxyl group, etc. is not generally contained in the trunk polymer which is a main component of the graft copolymer, and thus the performance such as adhesion to a substrate, pigment dispersibility, and alkali developability is not sufficient. There was no.

[0005] For ink application, see JP-A-3-17962.
No. 3,212,461, a radiation-curable ink composition comprising a graft polymer comprising a polymer of styrene or (meth) acrylate as a branch polymer and a radiation-reactive compound has been proposed. In addition, since the radiation-curable functional group was not contained in the graft polymer, the curability was insufficient.

There are many examples of using a graft copolymer in a radiation-curable composition for use in a color filter requiring dispersion performance. Printing methods, dyeing methods, electrodeposition methods, and pigment dispersion methods are known as methods for producing color filters used in liquid crystal display devices and solid-state imaging devices.

Among these methods, the pigment dispersion method is a method in which a pigment is dispersed in a radiation-curable composition and is prepared by a photolithographic method. Since the pigment is used, the pigment is excellent in light resistance and heat resistance. This method has the feature of being excellent in positional accuracy because it is a method, and is often used.

However, in a conventional radiation-curable composition,
Due to the poor dispersibility of the pigment, the light transmittance was poor, and there was a problem that the pigment aggregated over time. Further, there has been a problem that peeling from the substrate is apt to occur due to poor adhesion to the glass substrate, and background contamination and film residue are liable to occur due to poor alkali developability. As a method for solving such a problem, a method using an alkali-soluble block copolymer as a binder has been proposed in European Patent Publication No. 0564168A2. Defects were easy to generate.

On the other hand, as a method for highly dispersing a pigment, a graft copolymer containing a polystyrene or polyalkyl (meth) acrylate as a branch polymer is used as a dispersant or a binder resin, and a pigment and a radiation-curable compound are mixed with this. Compositions described in JP-A-9-179299 and JP-A-9-19
7118, JP-A-10-36622, JP-A-11-
No. 60657 or JP-A-11-64628.

However, since polystyrene and polybenzyl methacrylate are used for the purpose of improving the dispersibility of the branch copolymer of the graft copolymer, the hydrophobicity of the graft copolymer becomes stronger, the alkali solubility is reduced, and There have been problems that sometimes soiling and film residue are likely to occur and insufficient curability. On the other hand, as a method for improving the alkali solubility of a graft copolymer, a method of incorporating a large amount of a neutral and hydrophilic hydroxyl group or amide group is disclosed in JP-A-7-17-1.
No. 40654 and Japanese Patent Application Laid-Open No. 10-36622 propose that the solubility is improved but the curability and water resistance are inevitably reduced.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has been made to improve the dispersibility of pigments, compatibility with radiation-reactive compounds, curability, and adhesion to substrates. The present invention provides a novel radiation-curable composition having excellent properties, water resistance of a coating film, and alkali developability.

[0012]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, the present invention provides a radiation-curable graft copolymer comprising a branch polymer having a radiation-reactive polymerizable group and a carboxyl group and a trunk polymer having a radiation-reactive polymerizable group and a hydroxyl group; It is a curable composition comprising a compound having at least one (meth) acryloyl group and having a molecular weight of 100 to 5,000. In a more preferred embodiment, the radiation-curable graft copolymer has an acid value of 30 to 180 KOHmg / g, wherein the hydroxyl number is from 0.1 to 120 KOH mg / g. Hereinafter, the present invention will be described in detail.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The graft copolymer used in the present invention, comprising a branch polymer having a radiation-reactive polymerizable group and a carboxyl group, and a backbone polymer having a radiation-reactive polymerizable group and a hydroxyl group, It can be manufactured as follows.

That is, a typical production method is 1) a step of synthesizing a macromonomer having a carboxyl group, 2)
It comprises three steps: a step of synthesizing a graft copolymer having a hydroxyl group in the backbone, and 3) a step of introducing a radiation-reactive polymerizable group into the obtained graft copolymer. As described later, in step 2), a graft copolymer having a hydroxyl group and a carboxyl group in the trunk is synthesized to introduce a radioactive polymerizable group in step 3) by an inexpensive method. You can also.

Examples of a method for synthesizing a macromonomer having a carboxyl group include an acid decomposition method, a hydrolysis method, and an acid anhydride addition method. The acid decomposition method is a method in which tertiary alkyl (meth) acrylate is copolymerized and then decomposed with an acid catalyst under anhydrous conditions to obtain (meth) acrylic acid. The hydrolysis method is a method in which a lower alkyl (meth) acrylate, for example, methyl (meth) acrylate is copolymerized and then hydrolyzed with an acid catalyst or an alkali catalyst in the presence of water to obtain (meth) acrylic acid. The acid anhydride addition method is a method in which a hydroxyl group-containing monomer is copolymerized and then a dibasic anhydride, for example, succinic anhydride is subjected to an addition reaction with a hydroxyl group. An industrially optimum method is determined depending on the material of the apparatus, incidental facilities, costs and the like, but an acid anhydride adding method which does not require removal of water or an acid / alkali catalyst is preferable.

An example of a method for producing a macromonomer by an acid anhydride adding method is shown below. 2-hydroxyethyl methacrylate (HEMA) and benzyl methacrylate (Bz
M) is copolymerized in the presence of mercaptopropionic acid (MPA). Thereafter, glycidyl methacrylate (GMA) is caused to react with the carboxyl group at the terminal of the polymer derived from mercaptopropionic acid in the presence of a quaternary ammonium salt catalyst, thereby obtaining a macromonomer having an HEMA / BzM composition. Thereafter, the hydroxyl group derived from HEMA in the macromonomer is subsequently subjected to an addition reaction with succinic anhydride, whereby a carboxyl group-containing macromonomer can be obtained.

The carboxyl group has a structure with (meth) acrylic acid and itaconic acid groups in the acid decomposition method and the hydrolysis method, and the hydroxyalkyl (meth) acrylate and hydroxypolyalkoxyalkyl ( The structure has an addition reaction product of a hydroxyl group monomer such as meth) acrylate and polyester mono (meth) acrylate and an acid anhydride such as succinic anhydride, maleic anhydride and phthalic anhydride. Preferred amounts of carboxyl groups are
It is 2 to 180 KOH mg / g, more preferably 5 to 120 KOH mg / g based on the branch polymer. A value of 2 or less is not preferable because alkali solubility is reduced and soiling or film residue is likely to occur. A value of 180 or more is not preferable because water resistance is reduced.

In addition to the starting monomers used to introduce the carboxyl group into the branch polymer, the monomers forming the polymer portion of the macromonomer include alkyl (meth) acrylate, benzyl methacrylate, perfluoroalkyl (meth) acrylate, Examples include styrene, α-methylstyrene, vinyl carboxylate, and (meth) acrylamide. Preferably, alkyl (meth) acrylate, benzyl methacrylate, styrene or α-methylstyrene is used from the viewpoint of pigment dispersibility.

The number average molecular weight of the above macromonomer is preferably from 1,000 to 20,000 in terms of polystyrene by gel permeation chromatography.
If it is less than 1,000, the dispersibility is reduced.
If it exceeds 00, the copolymerizability is lowered and the desired dispersibility is not obtained, which is not preferred. A graft copolymer can be produced by copolymerizing the above-mentioned macromonomer with a monomer described below for forming a backbone polymer. The copolymerization ratio of the macromonomer is 1 to 1 based on the graft copolymer (solid content).
It is preferably 60% by weight, particularly preferably 3 to 50% by weight. If it is less than 1%, the dispersibility decreases, and 60%
In the case described above, the copolymerizability is lowered and cloudiness of the polymerization liquid is caused, which is liable to impair the transparency of the cured product.

By copolymerizing the above carboxyl group-containing macromonomer with a hydroxyl group-containing monomer and other monomers, a graft copolymer having a carboxyl group on the branch and a hydroxyl group on the trunk can be obtained. Further, by grafting a hydroxyl group-containing monomer, a carboxyl group-containing monomer and other monomers to the above-mentioned carboxyl group-containing macromonomer, to obtain a graft copolymer having a carboxyl group on a branch and a hydroxyl group and a carboxyl group on a trunk. Can be.

Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth) acrylate, hydroxypolyalkoxyalkyl (meth) acrylate, and polyester mono (meth) acrylate. Preferably, in terms of price, hydroxyalkyl (meth) acrylate, particularly 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypolyethylene glycol mono (meth) acrylate, hydroxypolypropylene glycol mono (Meth) acrylate,
Alternatively, these modified caprolactones, for example, Plaxel FM1 (manufactured by Daicel Chemical Industries, Ltd.) and the like can be mentioned.

The preferred amount of hydroxyl groups is from 0.1 to 120 KOH mg / g, based on the graft copolymer (solids).
And particularly preferably 0.1 to 80 KOHmg / g.
When it is 120 or more, alkali solubility increases, but water resistance decreases, which is not preferable.

The monomers used to introduce a carboxyl group into the backbone polymer include (meth) acrylic acid, itaconic acid and maleic acid. In addition, monomers used for purposes other than introducing a hydroxyl group or a carboxyl group into the trunk polymer include alkyl (meth) acrylate, benzyl methacrylate, perfluoroalkyl (meth) acrylate, styrene, α-methylstyrene, (meth) acrylamide and the like. Can be used,
From the viewpoint of pigment dispersibility, alkyl (meth) acrylate, benzyl methacrylate, styrene and the like can be preferably used alone or in combination. When the acid monomer is copolymerized with the backbone polymer, the preferred amount of the carboxyl group is from 30 to 180 as an acid value based on the graft copolymer (solid content).
KOHmg / g, more preferably 60 to 120 KOHm
g / g. When it is 30 or less, alkali solubility decreases, and it is not preferable because background soiling and film residue easily occur.
When it is more than 180, the water resistance is undesirably reduced.

The preferred molecular weight of the graft copolymer is from 8,000 to 100,000, particularly preferably from 10,000 to 50,000, by weight average molecular weight. JP-A-10-
No. 36622, the weight average molecular weight is 60,
It is not less than 000, but if it exceeds 50,000, the viscosity becomes high and the leveling property deteriorates, which is not preferable. In order to reduce the viscosity, it is possible to increase the number of compounds having one or more (meth) acryloyl groups in one molecule and having a molecular weight of 100 to 5,000 (hereinafter referred to as a reactive additive). It is not preferable because it decreases. On the other hand, if the molecular weight of the graft copolymer is less than 8,000, the strength of the coating film is undesirably reduced.

As a method for producing the graft copolymer, known methods can be used, but a solution polymerization is preferred since a solvent is required to improve the leveling property of the coating film. As the polymerization solvent, acetate esters and propionate esters are preferable, and among them, methoxyethyl acetate, methoxypropyl acetate, methoxybutyl acetate, ethoxyethyl acetate, alkoxyalkyl acetate such as ethoxypropyl acetate and the like, ethoxyethyl propionate, ethoxypropyl Alkoxyalkyl propionates such as propionate can be particularly preferably used.

Considering the post-process, the radiation-curable composition is applied to a glass substrate, for example, by a spin coater to have a thickness of 1 to 4.
It is preferable that the solvent has a boiling point of 200 ° C. or less so that a uniform film can be obtained under the drying condition of about 15 minutes at 80 ° C. by applying so as to have a thickness of 5 μm.
It is preferably at least 00 ° C.

A typical example of the radiation-reactive polymerizable group is a (meth) acryloyl group. An example of a method for introducing the glycidyl methacrylate into the graft polymer is described below. In the above solution of the graft copolymer having a carboxyl group on the branch and a hydroxyl group on the backbone, glycidyl methacrylate is added to the carboxyl group in the presence of a catalyst. 0.0 to 0.1 equivalent, 0.5 to 0.1 equivalent of isocyanatoethyl methacrylate relative to the hydroxyl group was added,
The reaction is completed by heating for several hours at a temperature between 120C and 120C. The amount of the radiation-reactive polymerizable group is preferably 50 or less, more preferably 1 to 20, per molecule of the copolymer. When the number is 50 or more, the ratio of no polymerization due to radiation increases, which is wasteful and not economical.

As a cheap and recommended alternative, a graft (co) polymer having a carboxyl group as a branch polymer and a hydroxyl group and a carboxyl group as a backbone polymer is synthesized, and then a carboxyl group bonded to the backbone polymer and the branch polymer. Glycidyl methacrylate is preferably used.

As the catalyst, a tertiary amine, a quaternary ammonium salt, a quaternary phosphonium salt and the like can be preferably used, and a quaternary ammonium salt, a quaternary phosphonium salt and an organic tin compound which are hardly colored are particularly preferable. Specifically, triethylbenzylammonium chloride, trimethylcetylammonium chloride, tetrabutylammonium bromide, tetrabutylphosphonium bromide, dibutyltin dilaurate and the like can be more preferably used.

The monomer to be reacted with the carboxyl group of the graft copolymer is glycidyl (meth) acrylate,
Methyl glycidyl (meth) acrylate, 3,4 epoxycyclohexylmethyl (meth) acrylate, aziridinyl methacrylate, etc.
Glycidyl methacrylate, methyl glycidyl (meth) acrylate and 3,4 epoxycyclohexylmethyl (meth) acrylate are preferably used in terms of price.

The reactive monomer to be reacted with the hydroxyl group of the graft copolymer includes isocyanate compounds such as isocyanate methacrylate, isocyanatoethyl methacrylate and isocyanatoisopropyl-α-methylstyrene. From the viewpoint of toxicity, isocyanatoisopropyl-α-methylstyrene is more preferred.

The reactive additive used together with the radiation-curable graft copolymer is a compound having at least one (meth) acryloyl group and has a boiling point of 100 ° C. or more from the viewpoint of air pollution and skin damage. Molecular weight 10
(Meth) acrylates that are from 0 to 5,000 are preferred. When the molecular weight is less than 100, toxicity problems due to monomer evaporation and risk of skin rash are increased, which is disadvantageous. When the molecular weight exceeds 5,000, the viscosity is high and the workability is reduced, and the solubility is lowered, so that it is highly possible that the graft copolymer cannot be completely dissolved.
It cannot be used due to problems such as reduced UV curability.

Specific examples of the reactive additive include polyalkylene glycol mono (meth) acrylate, phenoxyethyl (meth) acrylate, polyalkylene glycol di (meth) acrylate, trimethylolpropane mono, di or tri (meth) acrylate. Pentaerythritol mono, di, tri or tetra (meth) acrylate, dipentaerythritol (meth) acrylate, polyurethane di (meth) acrylate, polyester di (meth) acrylate, epoxy (meth) acrylate (Meth) acrylate modified with oxide or caprolactone.

There are no particular restrictions on the pigments used for color filters and inks, and conventionally known inorganic pigments and organic pigments can be used. Examples of the inorganic pigment include metal oxides and metal complexes such as iron, cobalt, aluminum, cadmium, lead, copper, titanium, chromium, and zinc. As organic pigments, C.I. I. Pigment Yellow, C.I.
I. Pigment Orange, C.I. I. Pigment Red, C.I. I.
Pigment Violet, C.I. I. Pigment Blue, C.I. I. Pigm
ent Green, C.I. I. Pigment Brown, C.I. I. Pigment
Black, etc. More than one pigment can be used for a particular color.

As a method of dispersing the above pigment, there are a flashing treatment, a kneader treatment, an extruder treatment,
Ball mill, roll mill, etc., especially 2 or 3
This roll mill treatment can be preferably used because the secondary aggregation of the pigment is converted into primary particles with a strong share.

Specific examples of the photopolymerization initiator added to initiate the polymerization of the cured composition of the present invention by irradiation of ultraviolet rays and electron beams include benzoin, benzoin methyl ether, benzoin alkyl ether, 9-fluorenone, and benzophenone. And acetophenone and benzothiazole compounds.

Other additives include a filler, a polymer compound other than the present invention, a surfactant, an adhesion improver, an antioxidant, an anti-agglomeration agent, an alkali solubility promoter represented by an organic carboxylic acid, A film forming aid, an anti-skinning agent, and the like are added.

After the curable composition of the present invention is applied to a substrate, it is polymerized and cured by irradiation with radiation such as ultraviolet rays or electron beams. As an ultraviolet light source, a wavelength of 250 to 450 n
high pressure mercury lamp containing a large amount of light of m, ultra-high pressure mercury lamp, a metal halide lamp and the like, practically acceptable ² intensity 1 mW / cm of light 365nm near the distance between Lamphu the irradiated object to be ~100mW / cm ² Are preferred. The electron beam irradiation apparatus is not particularly limited, but an apparatus having a dose in the range of 0.5 to 20 MRad is practically suitable.

When the curable composition of the present invention is used for a color filter, the curable composition is applied to a substrate by spin coating, flow coating, roll coating, or the like.
After drying at 0 ° C., the film is exposed to an electron beam or ultraviolet light via a predetermined mask pattern, developed with a developer, and washed with water.
Examples of the substrate include Pyrex glass, quartz glass, and silicon, and examples of the developer include 0.01% by weight to 1% by weight.
An aqueous solution of sodium hydroxide, sodium carbonate, potassium hydroxide, ammonia, triethylamine or the like by weight is used.

[0040]

The present invention will be described more specifically with reference to the following Reference Examples, Examples and Comparative Examples. In the following, parts represent parts by weight.

Reference Example 1 Synthesis Example of Carboxyl Group-Containing Macromonomer (M1) 1.5 parts of mercaptopropionic acid, propylene glycol monomethyl ether acetate (PGMAC) 11
0.28 parts, benzyl methacrylate (BzM) 30
Part, 2-hydroxyethyl methacrylate (HEMA)
1.43 parts were charged into a reaction flask. Heat to 93 ° C
After stirring, a mixture of 1.0 part of azobismethylisobutyronitrile (ABN-E) and 15 parts of PGMAC was added under a nitrogen stream for 5 hours, and 60 parts of BzM and 8.5 parts of HEMA were added.
7 parts were added over 3 hours to carry out polymerization. Heating was further continued for 2 hours to complete the polymerization. Number average molecular weight (M
n) = 6100, weight average molecular weight (Mw) = 11,80
A polymer having a carboxyl group at one terminal with an acid value of 0.0619 meq / g was obtained.

Switching to air bubbling,
2.21 parts of glycidyl methacrylate (GMA), 0.05 parts of methoxyphenol (MQ), 1.03 parts of tetrabutylammonium bromide (TBAB), PGMA
2.21 parts of C was charged and heated and stirred at 93 ° C. for 8 hours. When the acid value was measured, it was 0.001 meq / g, and the acid reaction rate was 98% or more, and it was confirmed that the reaction was completed. Mn
= 6,500 and Mw = 12,300, confirming that GMA was added to the terminal.

Thereafter, 3.84 parts of succinic anhydride (50% equivalent to the hydroxyl group) was added, and a heating reaction was continued under the same conditions. The acid value after 5 hours was measured to confirm that the conversion of succinic anhydride became 100% and the reaction was completed. The acid value of the obtained macromonomer solution is 0.1
67 meq / g, hydroxyl value 0.229 meq / g
g. Converted from 44.5% solid content to solid content,
Acid value 21.0 KOHmg / g Hydroxyl number 28.8
A carboxyl group-containing macromonomer of KOH mg / g was obtained. The molecular weight of the macromonomer is Mn = 7,60
0, Mw = 13,800.

Reference Example 2 Synthesis Example of a Graft Copolymer (G1) Having a Carboxyl Group on the Branch and a Hydroxyl Group and a Carboxyl Group on the Trunk 27 parts of BzM, methyl methacrylate (MMA) 27
Parts, HEMA 18 parts, methacrylic acid (MAA) 18 parts,
One part of mercaptopropionic acid was premixed. 9.1 parts of this monomer mixture solution, 22.22 parts of the macromonomer (M1) solution obtained in Reference Example 1, and 82.04 of PGMAC
After heating and stirring at 93 ° C., 2 parts of ABN-E and 31.6 of PGMAC were added under a nitrogen stream.
Five parts were added over 5 hours, and 81.9 parts of the remaining monomer solution were added over 3 hours to carry out polymerization. The mixture was further heated for 3 hours, and the polymerization was completed in a total of 8 hours to obtain a graft copolymer solution. As a result of GPC analysis, Mw = 19,800,
It was a graft copolymer with Mn = 8,700. At a solids content of 47.1%, the acid value of the solids was 54 KOH mg / g.

Reference Example 3 Synthesis Example of Radiation-Curable Graft Copolymer (G2) The graft copolymer solution obtained in Reference Example 2 was 228.93.
Parts, 9.81 parts of GMA (corresponding to 1/3 of the acid equivalent), TB
A flask is charged with 0.92 parts of AB, 10.77 parts of PGMAC, and 0.05 part of MQ. The mixture was heated and stirred at 93 ° C. for 5 hours while bubbling with air. It was confirmed by gas chromatography that GMA had almost completely disappeared, and the reaction was terminated. The acid value of the reaction solution before the reaction was 0.91 meq / g, but after 7 hours, the acid value was 0.62 meq / g, and the acid conversion rate was 32%, which was almost the same as the calculated reaction. I understood. The resulting graft copolymer solution has an acid value of 34.8 KOH mg / g and a hydroxyl value of 38.6.
KOH mg / g, the solid content concentration was 47.7%, and the molecular weight was Mn = 11,800 and Mw = 27,600.

Reference Example 4 Synthesis Example of Macromonomer (M2) Containing No Carboxyl Group Except that in Example 1 the total of 10 parts of HEMA used was changed to BzM and the total of 100 parts of BzM was used. Was polymerized in the same manner as in [Reference Example 1], and was subsequently converted into a macromonomer. The acid value was 0.001 meq / g or less, and the acid reaction rate was 98% or more. The molecular weight of the obtained BzM macromonomer was Mn = 6,900 and Mw = 1.
2,200.

Reference Example 5 Synthesis Example of Graft Copolymer (G3) Having No Carboxyl Group in Branch and Having Hydroxyl Group and Carboxyl Group in Trunk In Reference Example 2, the macromonomer (M1) solution was used. ,
A graft copolymer was produced in the same manner as in [Reference Example 2] except that the macromonomer (M2) solution obtained in [Reference Example 4] was changed, and the molecular weight was Mw = 20,500 and Mn = 9,300.
Was obtained.

Example 1 A mixture comprising the following raw materials was dispersed in a three-roll mill, and then filtered through a filter to obtain a radiation-curable composition. This composition was coated on a glass substrate by a spin coater so that the film thickness after drying became 2 μm, and prebaked at 100 ° C. for 5 minutes to obtain a blue film. Using a photomask having various lines / spaces, exposure was performed using an ultraviolet irradiation device having a light energy of 100 mJ / cm ² , development was performed using a 1% aqueous solution of sodium carbonate, and washing was performed with water. As a result of observing the relationship between the exposure amount and the pattern line width that can be formed with an optical microscope,
A 4-micron line could be formed, the image had sharp edges, and no background stain was observed in the non-pixel portion.

-Pigment C. I. Pigment Blue 15 100 parts-Graft copolymer (G2) solution of the present invention 250 parts-Dipentaerythritol pentaacrylate (molecular weight 524) 90 parts-Photopolymerization initiator * 1 9 parts-Leveling agent (L-7001, Nippon Unicar) 0.2 parts ・ Methoxypropyl acetate 790 parts ・ Polymerization inhibitor (methoxyphenol) 0.04 parts ・ Malonic acid 3 parts (Note) * 1; Manufactured by human peroxycyclohexyl phenyl ketone, dolphin cure 184

Comparative Example 1 Curable Composition Using a Graft Copolymer Having No Carboxyl Group in the Branch Polymer In Example 1, the graft copolymer (G2) was replaced with the graft copolymer (G3). The same operation was performed except that it was changed. As a result, a 4-micron line could be formed, and the image had sharp edges, but light cloudy contamination was partially observed in the non-pixel portion.

[0051]

Industrial Applicability The present invention is excellent in pigment dispersibility, curability, water resistance, adhesion, alkali resistance and the like, and is used for UV / electron beam curable ink, UV / electron beam curable paint / coating agent, and UV curable adhesive. Agent, photoresist ink, dry film, color filter, etc. For color filter applications, high resolution pixels can be provided by the photolithographic method, which does not cause background contamination on the color filter, black matrix, and glass substrate, and provides pixels with excellent adhesion to the substrate. it can.

Claims (2)

[Claims] 1. A radiation-curable graft copolymer comprising a radiation-reactive polymerizable group and a carboxyl group-containing branched polymer and a radiation-reactive polymerizable group and a hydroxyl group-containing backbone polymer; Having a molecular weight of at least 100 having at least one (meth) acryloyl group
A curable composition comprising 5,000 compounds. 2. The radiation-curable graft copolymer has an acid value of 30 to 180 KOH mg / g and a hydroxyl value of 0.1 to 1 KOH.
2. The curable composition according to claim 1, wherein the amount is 20 KOH mg / g.