JP3473495B2 - Curable composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a radiation-reactive curable composition. Specifically, it 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 / binder of a pigment for forming a color filter, has good dispersibility of the pigment, is excellent in adhesiveness with a substrate, alkali developability and coating film hardness, and has dispersed the pigment. A radiation curable composition.

In color filter applications, the steps of curing a radiation-curable composition, developing with alkali, and washing with water are repeated in red, green, and blue, so that particularly severe water resistance and alkali resistance are required, but the performance is high. Was insufficient. The curable composition of the present invention is particularly suitable for color filters in terms of pigment dispersibility, radiation curability, water resistance of coating film, alkali developability and the like.

[0003]

2. Description of the Related Art As an active energy ray-curable resin composition, a combination of an acrylic resin and a radiation-reactive compound has been conventionally known. Radiation-reactive compounds lack water resistance and flexibility but are excellent in radiation curability, whereas acrylic resins are excellent in water resistance and flexibility but lack radiation curability. By combining, the performance shortage is compensated. A method of introducing a radiation-curable functional group into an acrylic resin has also been proposed and partially put into practical use. However, in the trend of lightness, thinness, shortness and miniaturization in the industrial world, even higher water resistance, flexibility and curability are required, and recently, a graft polymer structure has attracted attention and many patents have been applied for.

In dry film applications, for example, Japanese Patent Laid-Open No.
3-32811, JP-A-2-84424, JP-A-2
-97516, JP-A-2-97517, JP-A-2-
No. 103215, JP-A-2-153916, JP-A-5-27432, and the like have been filed, and a trunk polymer mainly composed of a polymer of a monomer selected from the group consisting of alkyl (meth) acrylate, acrylonitrile and styrene. And a branch copolymer comprising a vinyl monomer having a hydroxyl group, an amino group, an alkylamino group and a carboxyl group, vinylpyrrolidone or a derivative thereof (for example, a carboxyl group modified with glycidyl methacrylate). Is proposed. However, since the trunk polymer which is usually the main component of the graft copolymer does not contain a functional group such as a carboxyl group or a hydroxyl group, the performance such as adhesion to a substrate, pigment dispersibility, and alkali developability is not sufficient. There was no

For ink use, Japanese Patent Laid-Open No. 3-179062
Japanese Patent Application Laid-Open No. 3-212461 is proposed, and a radiation curable ink composition is proposed in which a branch polymer is a graft polymer composed of a polymer of styrene or (meth) acrylate and a radiation reactive compound. 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 color filter applications in which dispersion performance is required. Printing methods, dyeing methods, electrodeposition methods, and pigment dispersion methods are known as methods for producing color filters used in liquid crystal display elements and solid-state imaging elements.

Among these methods, the pigment dispersion method is a method in which a pigment is dispersed in a radiation-curable composition and prepared by a photolithographic method. Since a pigment is used, it is excellent in light resistance and heat resistance. Since it is a method, it is characterized by excellent positional accuracy and is widely used.

However, in the conventional radiation curable composition,
Since the dispersibility of the pigment is poor, the light transmittance is poor, and there is a problem that the pigment aggregates over time. Further, there is a problem that peeling from the substrate is likely to occur due to poor adhesion to the glass substrate, and scumming and film residue are likely 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, but the viscosity becomes so high that filtration becomes difficult, and dust or foreign matter causes Defects were easy to generate.

On the other hand, as a method of highly dispersing the pigment, a graft copolymer having polystyrene or polyalkyl (meth) acrylate as a branch polymer is used as a dispersant or a binder resin, and the pigment and the radiation-curable compound are mixed therein. The compositions are disclosed 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 or polybenzyl methacrylate is used in the branch polymer of the graft copolymer for the purpose of improving the dispersibility, the hydrophobicity of the graft copolymer becomes strong and the alkali solubility is lowered, resulting in development. At times, there were problems such as scumming and film residue, and insufficient curability. On the other hand, as a method for improving the alkali solubility of the graft copolymer, a method of incorporating a large amount of neutral and hydrophilic hydroxyl group or amide group is disclosed in Japanese Patent Laid-Open No. 7-1.
As disclosed in Japanese Patent No. 40654 and Japanese Patent Application Laid-Open No. 10-36622, it is unavoidable that solubility is improved but curability and water resistance are reduced.

[0011]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is the dispersibility of the pigment, the compatibility with the radiation-reactive compound, the curability, and the adhesion with the substrate. The present invention provides a novel radiation curable composition having excellent properties, water resistance of a coating film, and alkali developability.

[0012]

The present inventor has completed the present invention as a result of extensive studies to solve the above problems. That is, the present invention relates to 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, and to one molecule. A curable composition comprising a compound having one or more (meth) acryloyl groups and having a molecular weight of 100 to 5,000, and a more preferred embodiment, wherein the radiation curable graft copolymer has an acid value of 30 to 180 KOHmg / The above curable composition has a hydroxyl value of 0.1 to 120 KOHmg / g. Hereinafter, the present invention will be described in detail.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A graft copolymer used in the present invention, which comprises 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, is It can be manufactured as follows.

That is, a typical production method is as follows: 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 trunk, and a step 3) of introducing a radiation-reactive polymerizable group into the obtained graft copolymer. As will be described later, by synthesizing a graft copolymer having a hydroxyl group and a carboxyl group on the trunk in the step 2), the radioactive reactive polymerizable group is introduced by an inexpensive method in the step 3). You can also do it.

Examples of the 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 a tertiary alkyl (meth) acrylate is copolymerized and then decomposed with an acid catalyst under anhydrous conditions to give (meth) acrylic acid. The hydrolysis method is a method in which a lower alkyl (meth) acrylate, such as methyl (meth) acrylate, is copolymerized and then hydrolyzed with an acid catalyst or an alkali catalyst in the presence of water to give (meth) acrylic acid. The acid anhydride addition method is a method in which a dibasic anhydride such as succinic anhydride is subjected to an addition reaction with a hydroxyl group after copolymerizing a monomer containing a hydroxyl group. The industrially optimum method is determined depending on the material of the apparatus, incidental equipment, cost, etc., but the acid anhydride addition method that does not require removal of water or acid / alkali catalyst is preferable.

An example of the method for producing a macromonomer by the acid anhydride addition method is shown below. 2-hydroxyethyl methacrylate (HEMA) and benzyl methacrylate (Bz
M) is copolymerized in the presence of mercaptopropionic acid (MPA). Then, the carboxyl group at the terminal of the polymer derived from mercaptopropionic acid is reacted with glycidyl methacrylate (GMA) in the presence of a quaternary ammonium salt catalyst to once obtain a macromonomer having a HEMA / BzM composition. Thereafter, the hydroxyl group derived from HEMA in this 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 having (meth) acrylic acid or itaconic acid group in the acid decomposition method or the hydrolysis method, and in the acid anhydride addition method, hydroxyalkyl (meth) acrylate or hydroxypolyalkoxyalkyl ( It has a structure in which a hydroxyl group monomer such as (meth) acrylate or polyester mono (meth) acrylate and an acid anhydride addition reaction product such as succinic anhydride, maleic anhydride or phthalic anhydride are attached. The preferred amount of carboxyl group is
It is 2-180 KOHmg / g, more preferably 5-120 KOHmg / g, based on the branched polymer. When it is 2 or less, alkali solubility is lowered, and scumming and film residue are likely to occur, which is not preferable, and when 180 or more, water resistance is lowered, which is not preferable.

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

The number average molecular weight of the macromonomer is preferably 1,000 to 20,000 in terms of polystyrene by gel permeation chromatography.
If it is less than 1,000, the dispersibility will decrease, so
When it exceeds 00, the copolymerizability is lowered and the desired dispersibility is not obtained, which is not preferable. A graft copolymer can be produced by copolymerizing the above-mentioned macromonomer and the following monomer for forming a trunk polymer. The copolymerization ratio of the macromonomer is 1 to 1 on the basis of the graft copolymer (solid content).
60% by weight is preferable, and particularly 3 to 50% by weight can be preferably added. If it is less than 1%, the dispersibility decreases, and 60%.
In the above cases, the copolymerizability is lowered to cause cloudiness of the polymerization solution, which easily deteriorates the transparency of the cured product, which is not preferable.

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

Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth) acrylate, hydroxypolyalkoxyalkyl (meth) acrylate and polyester mono (meth) acrylate. From the viewpoint of price, preferably, 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, a modified form of these caprolactones, such as Praxel FM1 (manufactured by Daicel Chemical Industries, Ltd.) and the like can be mentioned.

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

Monomers used for introducing a carboxyl group into the trunk polymer include (meth) acrylic acid, itaconic acid and maleic acid. Further, as monomers used for purposes other than introducing a hydroxyl group or a carboxyl group into the trunk polymer, alkyl (meth) acrylate, benzyl methacrylate, perfluoroalkyl (meth) acrylate, styrene, α-methylstyrene, (meth) acrylamide, etc. 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. The preferable amount of the carboxyl group when the acid monomer is copolymerized with the trunk polymer is 30 to 180 as the acid value on the basis of the graft copolymer (solid content).
KOH mg / g, more preferably 60 to 120 KOHm
It is g / g. When it is 30 or less, alkali solubility is lowered, and scumming and film residue easily occur, which is not preferable.
When it is 180 or more, the water resistance decreases, which is not preferable.

The weight average molecular weight of the graft copolymer is preferably 8,000 to 100,000, and particularly preferably 10,000 to 50,000. JP-A-10-
In the example of Japanese Patent No. 36622, the weight average molecular weight is 60,
However, if it exceeds 50,000, the viscosity becomes high and the leveling property is deteriorated. In order to reduce the viscosity, a compound having one or more (meth) acryloyl groups in the molecule and having a molecular weight of 100 to 5,000 (hereinafter referred to as a reactive additive) can be increased, but the dispersion performance is improved. It is not preferable because it decreases. Further, if the molecular weight of the graft copolymer is less than 8,000, the strength of the coating film decreases, which is not preferable.

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

Considering the subsequent steps, the radiation-curable composition is applied to, for example, a glass substrate with a spin coater to give a film thickness of 1 to 1.
It is preferable that the boiling point of the solvent is 200 ° C or lower so that a uniform film can be obtained under a drying condition of about 15 minutes at 80 ° C.
It is preferably 00 ° C or higher.

The radiation-reactive polymerizable group is typically a (meth) acryloyl group. An example of a method for introducing it into a graft polymer will be described. To a solution of a graft copolymer having a carboxyl group in a branch and a hydroxyl group in a trunk in the presence of a catalyst, glycidyl methacrylate is added to the carboxyl group in an amount of 1 0.0 to 0.1 times equivalent amount, and 0.5 to 0.1 times equivalent amount of isocyanate ethyl methacrylate to the hydroxyl group are added,
The reaction is completed by heating at ℃ to 120 ℃ for several hours. 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 polymerization due to radiation increases, which is wasteful and uneconomical.

As an alternative method which can be recommended at low cost, a carboxyl group is bonded to the trunk polymer after synthesizing a graft (co) polymer having a carboxyl group in the branch polymer and a hydroxyl group and a carboxyl group in the trunk polymer. On the other hand, there is a method of reacting glycidyl methacrylate, which can be preferably used.

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

The monomer reacted with the carboxyl group of the graft copolymer is glycidyl (meth) acrylate,
Examples thereof include 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 recommended from the viewpoint of price.

Examples of the reactive monomer which reacts with the hydroxyl group of the graft copolymer include isocyanate compounds such as isocyanate methacrylate, isocyanate ethyl methacrylate, and isocyanate isopropyl-α-methylstyrene, but the price, fogging, etc. From the toxicity of, isocyanatoisopropyl-α-methylstyrene is more preferable.

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 higher from the viewpoint of air pollution and skin damage. Molecular weight is 10
(Meth) acrylates of 0 to 5,000 are preferred. If the molecular weight is less than 100, there is a high risk of toxicity due to monomer evaporation and the risk of skin irritation, which is inconvenient. When the molecular weight exceeds 5,000, the viscosity is high and the workability is lowered, 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 deterioration in 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 or the raw material alcohol of these compounds is alkylene Examples thereof include (meth) acrylate modified with oxide or caprolactone.

There is no particular limitation on the pigment used in the color filter or ink application, and conventionally known inorganic pigments and organic pigments can be used. Examples of the inorganic pigment include metal oxides and metal complexes of iron, cobalt, aluminum, cadmium, lead, copper, titanium, chromium, zinc and the like. Examples of organic pigments include 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. can be given. It is also possible to use more than one pigment for a particular color.

As a method for dispersing the above pigment, a flushing process, a kneader process, an extruder process,
Examples include ball mills and roll mills, 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 which is added to the curable composition of the present invention to initiate polymerization by irradiation with ultraviolet rays or electron beams include benzoin, benzoin methyl ether, benzoin alkyl ether, 9-fluorenone and benzophenone. Conventionally known compounds such as acetophenone, benzothiazole compound and the like can be mentioned.

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

After being coated on a substrate, the curable composition of the present invention 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 450n
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 Something is preferable. The electron beam irradiation device is not particularly limited, but a device 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, it is applied to a substrate by spin coating, flow coating, roll coating, etc.
After drying at 0 ° C., it is exposed to an electron beam or ultraviolet rays through a predetermined mask pattern, developed with a developing solution, and washed with water.
Examples of the substrate include Pyrex glass, quartz glass, silicon, and the like. The developer is 0.01% by weight to 1%.
An aqueous solution of sodium hydroxide, sodium carbonate, potassium hydroxide, ammonia, triethylamine or the like at a weight percentage is used.

[0040]

EXAMPLES 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 Synthetic 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)
A reaction flask was charged with 1.43 parts. Heated to 93 ° C
After stirring, under a nitrogen stream, a mixed solution of 1.0 part of azobismethylisobutyronitrile (ABN-E) and 15 parts of PGMAC was added over 5 hours to 60 parts of BzM and 8.5 parts of HEMA.
7 parts of each was added and polymerized over 3 hours. The polymerization was completed by heating for another 2 hours. Number average molecular weight (M
n) = 6100, weight average molecular weight (Mw) = 1,80
A polymer having a carboxyl group at one end and an acid value of 0 and an acid value of 0.0619 meq / g was obtained.

After switching to air bubbling,
Glycidyl methacrylate (GMA) 2.21 parts, methoxyphenol (MQ) 0.05 parts, tetrabutylammonium bromide (TBAB) 1.03 parts, PGMA
C. 2.21 parts were charged and the mixture was heated with stirring at 93 ° C. for 8 hours. When the acid value was measured, it was 0.001 meq / g, the acid reaction rate was 98% or more, and the completion of the reaction could be confirmed. Mn
= 6,500, Mw = 12,300, and it was confirmed that GMA was added to the end.

Then, 3.84 parts of succinic anhydride (50% equivalent to the hydroxyl group) was added, and the heating reaction was continued under the same conditions. After 5 hours, the acid value was measured, and it was confirmed that the conversion rate of succinic anhydride was 100% and the reaction was completed. The acid value of the obtained macromonomer solution is 0.1.
67 meq / g, hydroxyl value is 0.229 meq / g
It was g. Solid content conversion from solid content concentration 44.5%,
Acid value 21.0 KOHmg / g Hydroxyl value 28.8
A carboxyl group-containing macromonomer having a 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 Graft Copolymer (G1) Containing Carboxyl Group on Branch and Hydroxyl Group and Carboxyl Group on Trunk BzM (27 parts), Methyl Methacrylate (MMA) 27
Part, HEMA 18 parts, methacrylic acid (MAA) 18 parts,
1 part of mercaptopropionic acid was premixed. 9.2 parts of this monomer mixed solution, 22.22 parts of the macromonomer (M1) solution obtained in [Reference Example 1], and 82.04 of PGMAC
1 part was placed in a flask, heated to 93 ° C. and stirred, and then, under a nitrogen stream, 2 parts of ABN-E and 31.6 parts of PGMAC.
Polymerization was carried out by adding 5 parts over 5 hours and 81.9 parts over the remaining monomer solution over 3 hours, respectively. The mixture was heated for another 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. The solid content was 47.1%, and the acid value of the solid content was 54 KOHmg / 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 acid equivalent), TB
A flask is charged with 0.92 parts of AB, 10.77 parts of PGMAC and 0.05 parts 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 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 became 0.62 meq / g, and the reaction was almost as calculated with an acid conversion rate of 32%. I understood. The obtained graft copolymer solution had an acid value of 34.8 KOHmg / g and a hydroxyl value of 38.6.
KOHmg / g, the solid content concentration was 47.7%, and the molecular weights were Mn = 1,800 and Mw = 27,600.

[Reference Example 4] In the synthesis example [Reference Example 1] of a macromonomer (M2) containing no carboxyl group, the total of 10 parts of HEMA used was changed to BzM to make 100 parts of BzM in total. Was polymerized in the same manner as in [Reference Example 1], and 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, Mw = 1.
It was 2,200.

[Reference Example 5] In a synthesis example [Reference Example 2] of a graft copolymer (G3) having a carboxyl group on a branch and a hydroxyl group and a carboxyl group on a trunk, a macromonomer (M1) solution was prepared. ,
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 used, and the molecular weight was Mw = 20,500, Mn = 9,300.
A graft copolymer of was obtained.

Example 1 A mixture of the following raw materials was dispersed with a three-roll mill and filtered with a filter to obtain a radiation curable composition. A glass substrate was coated with this composition by a spin coater so that the film thickness after drying was 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 with an ultraviolet irradiation device having a light energy of 100 mJ / cm ² , development was performed using a 1% sodium carbonate aqueous solution, and further washing with water was performed. 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 smear was found in the non-pixel areas.

[0049] ・ Pigment C. I. Pigment Blue 15 100 copies 250 parts of the graft copolymer (G2) solution of the present invention -Dipentaerythritol pentaacrylate (molecular weight 524) 90 parts ・ Photopolymerization initiator * 1 9 parts ・ Leveling agent (L-7001, made by Nippon Unicar) 0.2 parts ・ Methoxypropyl acetate 790 parts ・ Polymerization inhibitor (methoxyphenol) 0.04 parts ・ 3 parts malonic acid   (Note) * 1: Human oxycyclohexyl-phenyl ketone, Irgacure 184, manufactured by Ciba Geigy

[Comparative Example 1] In the curable composition [Example 1] using a graft copolymer having no carboxyl group in the branch polymer, 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 line of 4 μm could be formed, and the image had sharp edges, but light cloudy contamination was partially seen in the non-pixel portion.

[0051]

INDUSTRIAL APPLICABILITY The present invention is excellent in pigment dispersibility, curability, water resistance, adhesiveness, alkali resistance, etc., and is UV / electron beam curable ink, UV / electron beam curable paint / coating agent, UV curable adhesive. It can be applied to agents, photoresist inks, dry films and color filters. For color filter applications, it is possible to provide high-definition pixels by the photolithography method, and to provide pixels with excellent adhesion to the substrate without causing scumming on the color filter, black matrix and glass substrate. it can.

Front page continued (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08F 290/00 G03F 7/027 C08F 8/14 G02B 5/20

Claims (2)

(57) [Claims] 1. 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, and one molecule. The molecular weight having one or more (meth) acryloyl groups is 100 to
A curable composition consisting of 5,000 compounds. 2. A radiation-curable graft copolymer having an acid value of 30 to 180 KOHmg / g and a hydroxyl value of 0.1 to 1.
The curable composition of claim 1 which is 20 KOHmg / g.