JPH1180292A - Hydrophilic photocurable resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which can be washed off with water or a water/alcohol solvent even when it is left in the applicator or the container by including an acryloyl-modified unsaturated polyester (A) with a hydrophilic polymerizable monomer (B) and a photopolymerization initiator (C). SOLUTION: Component A is obtained by reacting an unsaturated polyester essentially made from an α,β-unsaturated polybasic acid component and 5- sodiosulfoisophthalic acid and having an acid value of 25-100 with an acryloylglycidyl-containing compound (e.g. glycidyl methacrylate). Component B is exemplified by 2-hydroxyethyl acrylate. Component C is exemplified by benzoin methyl ether. The mixing ratio is such that 95-20 wt.%, based on the total weight of components A and B, is used, and 0.01-10 wt.%, based on the total weight of components A and B, component C is used. This composition can give a thick coating film excellent in the balance of cure between its surface and its inside, durability, polishability, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrophilic and photocurable resin composition, and more particularly, to a machine coated with the resin composition having excellent characteristics even at a high film thickness. The present invention relates to a hydrophilic curable resin composition capable of washing a container or the like with water.

[0002]

2. Description of the Related Art Conventionally, resin compositions which are cured by irradiation with light such as ultraviolet rays have been put to practical use in various applications such as paints and adhesives for plastics, paper, woodwork, inorganic materials, etc., printing inks and electrical insulation. ing. Curing by light has features such as i) extremely high curing speed and high productivity, and ii) little influence of heat on the material. Known resins that cure by light irradiation include unsaturated polyester resins, epoxy acrylate resins, urethane acrylates, polyester acrylate resins, and the like. Many resins are used. However, when washing a coating machine, a container, and the like using the resin composition, a solvent such as an aromatic solvent, a ketone, or an ester solvent must be used. Further, when this resin composition is used so that the coating film has a thickness of 500 μm or more, cracks are generated on the coating film surface, and the coating film is peeled off from the base material by repeated heat and cooling, and further the coating film surface portion There are drawbacks such as insufficient curing due to the influence of air and difficulty in polishing.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, and enables washing of machines and containers after coating with water or a water / alcohol-based solvent, and at the same time, high film thickness. The present invention also provides a hydrophilic and photo-curable resin composition capable of forming a coating film having an excellent curing balance between the surface and the inside of the coating film and having excellent durability and polishing properties.

[0004]

The present invention relates to (A) α, β
An unsaturated polybasic acid component and 5- (sodium sulfonate) isophthalic acid as essential components, and having an acid value of 25 to 100;
Acryloyl-modified unsaturated polyester obtained by reacting a (meth) acryloylglycidyl-containing compound with the unsaturated polyester as described above, (B) a hydrophilic photopolymerizable monomer, and (C) a hydrophilic polymer containing a photopolymerization initiator. The present invention relates to a resin composition which is curable and photocurable. The present invention also provides the resin composition, wherein the component (A) is contained in an amount of 95 to 20% by weight based on the total amount of the acryloyl-modified unsaturated polyester (A) and the hydrophilic photopolymerizable monomer (B). The photopolymerization initiator (C) is used in an amount of 0.0 with respect to the total amount of the components (A) and (B).
The present invention relates to a hydrophilic and photocurable resin composition containing 1 to 10% by weight.

The acryloyl-modified unsaturated polyester, which is the component (A) used in the present invention, is obtained by reacting the (a) acid component with the (b) glycol component, and reacting the reaction product with the (c)
It is obtained by reacting a (meth) acryloylglycidyl-containing compound. The acid component (a) is an α, β-unsaturated polybasic acid component and 5- (sodium sulfonate) isophthalic acid represented by the following structural formula (hereinafter abbreviated as 5SSIPA).
Is used as an essential component.

Embedded image

[0006] 5SSIPA is preferably in the range of 0.03 to 0.25 mol, more preferably 0.03 to 0.20 mol, particularly preferably 0.03 to 0.18 mol, based on 1 mol of the whole acid component. Used in the range. 5SSI
When the use ratio of PA is less than 0.03 mol, the imparting of hydrophilicity tends to be insufficient, and when it exceeds 0.25 mol, the hydrophilicity becomes too strong and the water resistance and alkali resistance of the coating film tend to decrease. There is.

[0007] 5SSIPA is one of the saturated polybasic acid components, and other saturated polybasic acid components include phthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, heptic acid, and adipine. An acid, sebacic acid or the like can be used in combination, and these are used alone or in combination of two or more. The entire saturated polybasic acid component is
The total amount of the acid component is preferably 1 mol to 0.03 to 0.1 mol.
70 mol, more preferably 0.03 to 0.50 mol,
Particularly preferably, it is used in a proportion of 0.03 to 0.40 mol. If the amount of the saturated polybasic acid component is too low, it becomes impossible to use water when washing a coating machine, a coating container, and the like.
On the other hand, if the amount of the saturated polybasic acid component is too large, the curability of the light-irradiated coating film is insufficient, and the properties such as solvent resistance, hardness, and chemical resistance of the coating film tend to decrease.

In the acid component, the remaining 5SSIPA or the saturated polybasic acid component is an α, β-unsaturated polybasic acid component. As the α, β-unsaturated polybasic acid component, for example, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride and the like can be used. These are used alone or in combination of two or more.

The glycol component (b) is neopentyl glycol, 1,4-cyclohexanedimethanol,
Ethylene glycol, propylene glycol, 1,4-
Butylene glycol, 1,3-butylene glycol,
There are 1,6-hexane glycol, hydrogenated bisphenol A, etc., and further, ether group-containing glycols (condensed dimer or condensed multimer of alkylene glycol) such as diethylene glycol, triethylene glycol, and dipropylene glycol may be used. it can. When the glycol containing ether group increases, 5SS in the acid component during the condensation reaction
Since acid decomposition is easily caused by IPA, the ether group-containing glycol is preferably used in an amount of 0 to 0.70 mol, more preferably 0 to 0.7 mol per 1 mol of the entire glycol component.
It is used in a proportion of 0.60 mol, particularly preferably 0 to 0.50 mol.

In the present invention, the unsaturated polyester is
The acid value is adjusted to 25 to 100, preferably 30 to 70. If the acid value of the unsaturated polyester is less than 25, the number of reaction points (introduction points) with the component (c) (meth) acryloylglycidyl-containing compound described below decreases, and the curing speed of the coating film after light irradiation extremely decreases. Conversely, if the acid value exceeds 100, the molecular weight does not become sufficiently large, and the quasi-film after light irradiation is liable to crack in the coating film in repeated heat and cooling tests. In order to adjust the acid value of the unsaturated polyester to 25 to 100, the component (a) and the component (b) are used in an amount of the component (b) per mole of the component (a), preferably 1.2 to 0. .
7 moles, more preferably 1.15 to 0.8 moles, are reacted in a conventional manner.

The unsaturated polyester obtained by reacting the component (a) with the component (b) is reacted with a compound containing (meth) acryloylglycidyl as the component (c) to obtain the component (A). Certain acryloyl-modified unsaturated polyesters are obtained. As the component (c), the glycidyl group is preferably used in an amount of 1.00 to 0.50 equivalent (glycidyl group / carboxyl group), more preferably 1.00 to 0.80, based on the carboxyl group of the unsaturated polyester. The reaction is carried out at room temperature to obtain an acryloyl-modified unsaturated polyester (A).

When the amount of the (meth) acryloylglycidyl-containing compound (c) used exceeds the equivalent to the carboxyl group of the unsaturated polyester, the free (meth) acryloylglycidyl-containing compound in the acryloyl-modified unsaturated polyester (A) is free. , The hydrophilicity of the resin composition tends to decrease. If the amount is less than 0.50 equivalents, the self-curing property of the acryloyl-modified unsaturated polyester (A) with respect to photocuring decreases, and if a hydrophilic solvent is used alone as the component (B), the coating film after light irradiation is sufficiently cured. Therefore, hardness, water resistance, chemical resistance, and the like tend to be significantly reduced. Examples of the (meth) acryloylglycidyl-containing compound (c) include glycidyl methacrylate and glycidyl acrylate.

The acryloyl-modified unsaturated polyester (A) is synthesized by a known method. For example, 5SSIPA of the component (a) and part or all of the component (b) and a small amount of a tin compound as a reaction catalyst are charged into a reaction vessel, and 15
Heating at 0 to 220 ° C. for 1 to 5 hours while removing reaction water,
The reaction is continued until the acid value becomes 2 or less. Thereafter, the remaining components (a) and (b) are charged, and the mixture is heated at 150 to 220 ° C. for 3 to 20 hours while removing the reaction water in the same manner to adjust the acid value to a predetermined value to obtain an unsaturated polyester. . The acryloyl-modified unsaturated polyester (A) can be obtained by reacting the unsaturated polyester with a (meth) acryloylglycidyl-containing compound. The reaction is preferably carried out until the glycidyl group of the (meth) acryloylglycidyl-containing compound disappears, and the reaction temperature is preferably from 50 to 120 ° C. At the time of this reaction, it is preferable to use a reaction catalyst. As a reaction catalyst, ammonium chloride, ammonium salts such as dodecylbenzylammonium chloride, triethylamine, tertiary amine compounds such as tripropylamine,
There are organic salts of alkali metals such as potassium benzoate. The amount of the reaction catalyst used is preferably 0.1 to 1% by weight based on the (meth) acryloylglycidyl-containing compound.

In the present invention, a hydrophilic photopolymerizable monomer (B) is used. Examples of the hydrophilic photopolymerizable monomer include 2
-Hydroxy group-containing (meth) acrylates such as -hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl (Meth) acrylic acid amino esters such as methacrylate. Any one of the above hydrophilic photopolymerizable monomers may be used, or two or more of them may be used in combination.

The photopolymerization initiator (C) used in the present invention includes benzoin alkyl ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin propyl ether; 2,2-diethoxyacetophenone and 4'- Acetophenones such as phenoxy-2,2-dichloroacetophenone; 2-hydroxy-2
-Methyl-propiophenone, 4'-isopropyl-2
Propiophenones such as -hydroxy-2-methylpropiophenone, 4'-dodecyl-2-hydroxy-2-methylpropiophenone;benzyldimethylketal;
Anthraquinones such as 1-hydroxycyclohexylphenyl ketone, 2-ethylanthraquinone, and 2-chloroanthraquinone; thioxanthones; and the like can be used alone or in combination of two or more. Further, a synergist, for example, a tertiary amine, may be used to enhance the conversion of the light absorption energy of the photopolymerization initiator into free radicals for initiation of polymerization.

In the resin composition of the present invention, the amount of the acryloyl-modified unsaturated polyester (A) used is
It is preferably 95 to 20% by weight, more preferably 80 to 20% by weight based on the total amount of the hydrophilic photopolymerizable monomer of the component and the component (B).
30% by weight, and the amount of the hydrophilic photopolymerizable monomer (B) used is preferably 5 to 5% with respect to the total amount of the above (A) and (B).
It is 80% by weight, more preferably 20 to 70% by weight.
When the use amount of the component (B) is less than 5% by weight, the viscosity of the resin composition tends to be high and the handling tends to be difficult. Also 80
If the amount is more than 10 parts by weight, the amount of the acryloyl-modified unsaturated polyester (A) becomes small, the prevention of curing inhibition by oxygen at the time of light irradiation is not sufficient, and when the film thickness is large, the surface of the coating film becomes sticky. And the toughness of the coating film tends to decrease.

The amount of the photopolymerization initiator (C) is preferably 0.01 to 10% by weight based on the total amount of the acryloyl-modified unsaturated polyester (A) and the hydrophilic photopolymerizable monomer (B). More preferably, it is 0.05 to 7% by weight. If the amount is less than 0.01% by weight, curing at the time of light irradiation becomes insufficient, and adhesiveness tends to remain on the coating film surface.
If the amount exceeds the weight percentage, the curing is not particularly accelerated due to the increase in the amount used during light irradiation, which is economically disadvantageous.

The resin composition of the present invention may contain, if necessary,
A hydrophilic solvent can be present. Examples of the hydrophilic solvent include water and hydrophilic organic solvents, for example, alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, secondary butyl alcohol, and tertiary butyl alcohol, and methyl cellosolve. , Cellosolves such as butyl cellosolve, ketones such as acetone, diacetone alcohol and ethyl methyl ketone, and ester compounds such as ethyl acetate. The hydrophilic solvent comprises the component (A),
It is preferably 40% by weight or less based on the total amount of the component (B) and the hydrophilic solvent, and more preferably the same weight or less based on the hydrophilic photopolymerizable monomer (B). The hydrophilic solvent is preferably used by mixing it with the component (A) in order to impart fluidity to the component (A) in advance.

The resin composition of the present invention may contain, if necessary, a polymerization inhibitor such as hydroquinone or toluquinone, an ultraviolet absorber such as phenyl salicylate or 4-t-butylphenyl salicylate, a filler such as calcium carbonate or talc, , Pigments such as titanium white, dyes such as aniline black,
The composition may contain a leveling agent such as silicone and cellulose acetate butyrate, a defoaming agent such as various silicones, a thixotropic agent such as silicon dioxide, and a matting agent such as fused silica. The resin composition of the present invention, for example, sprayed on a substrate, brush coating, flow coater, roll coater, after applying by dipping or the like, and then irradiating light under an inert gas atmosphere such as nitrogen gas or air atmosphere. Can be cured. The light source used at this time includes sunlight, a carbon arc lamp composed of an artificial light source, a mercury vapor lamp, and the like.
A wavelength of 使用 is used and can be cured by an electron beam.

[0020]

Next, the present invention will be described in more detail with reference to examples. In the examples below, “parts” and “%” mean “parts by weight” and “% by weight”, respectively, unless otherwise specified. Acryloyl-modified unsaturated polyesters used in the examples (A-1, A-2, A-3 and Z-2)
And unsaturated polyester (Z-1) was synthesized as follows. Further, Table 1 summarizes the amounts of the respective components of these synthetic resins.

(1) Synthesis of Acryloyl-Modified Unsaturated Polyester (A-1) 149.1 parts of 5SSIPA (manufactured by Eastman Chemical Company) in a 2 liter flask equipped with a stirrer, gas inlet tube, reflux condenser and thermometer. (0.53 mol), 468.0 parts (4.50 mol) of neopentyl glycol and 0.5 part of dibutyltin laurate, and heated to 150 ° C. in 1 hour while blowing nitrogen gas, and further heated to 150 ° C. From 200 ° C. to 200 ° C. in 3 hours, and heated at the same temperature until the acid value of the contents in the kettle became 2 or less. An acid value of 1.2 (KOHmg / g) was shown 3 hours after the temperature was raised at 200 ° C. Then 120 ° C
And cooled to 262.2 parts (1.73 mol) of tetrahydrophthalic anhydride, 609.0 parts (5.25 mol) of fumaric acid, 318.0 parts (3.00 mol) of diethylene glycol and 0.2 part of hydroquinone At 150 ° C.
The temperature was further increased from 150 ° C. to 200 ° C. for 4 hours, and the mixture was heated at the same temperature until the acid value of the content in the kettle became 50. Six hours after heating at 200 ° C., the acid value was 49.8, and the amount of condensed water for reaction was 205 parts (hereinafter, this reaction product is referred to as resin X-1).

Thereafter, after cooling to 100 ° C., the nitrogen gas was switched to air blowing, and glycidyl methacrylate was used.
9 parts (glycidyl group / carboxyl group = 1.0, equivalent ratio) and 1.1 parts of benzalkonium chloride were added, and 1 part was added.
The temperature was raised to 20 ° C., and the mixture was heated at the same temperature until the acid value of the contents in the kettle became 3 or less. After heating at 120 ° C., an acryloyl-modified unsaturated polyester (hereinafter, referred to as A-1) having an acid value of 2.6 was obtained in 12 hours.

(2) Synthesis of Acryloyl-Modified Unsaturated Polyester (A-2) 5 SSIP was placed in the same 2 liter flask as in Example 1.
A, 186.0 parts (0.66 mol), 72,4 parts (4.58 mol) of 1,4-cyclohexanedimethanol and 0.6 part of dibutyltin laurate were charged and heated to 200 ° C. in the same manner as in Example 1. The temperature was raised and heated at the same temperature until the acid value of the contents in the kettle became 2 or less. An acid value of 1.1 was shown 4.5 hours after the temperature was raised at 200 ° C. Thereafter, the mixture was cooled to 120 ° C., 683.8 parts (4.50 mol) of fumaric acid, 208.3 parts (1.97 mol) of diethylene glycol and 0.2 part of hydroquinone were added, and the temperature was raised to 150 ° C.
The temperature was raised from 50 ° C. to 180 ° C. over 3 hours and heated at the same temperature until the acid value of the contents in the kettle became 65. 9 hours after the temperature was raised to 180 ° C., the acid value was 64.2, and the amount of condensed water for reaction was 230.
Part (resin X-2). Then cool to 100 ° C,
The nitrogen gas was switched to air blowing, and 255.5 parts of glycidyl methacrylate (glycidyl group / carboxyl group =
(1.0, equivalent ratio) and 1.4 parts of benzalkonium chloride were added, the temperature was raised to 120 ° C, and the mixture was heated at the same temperature until the acid value of the contents in the kettle became 3 or less. After heating at 120 ° C, 14
An acryloyl-modified unsaturated polyester (A-2) having an acid value of 2.2 over time was obtained.

(3) Synthesis of Acryloyl-Modified Unsaturated Polyester (A-3) 5 SSIPA was placed in the same 2 liter flask as in Example 1.
230.0 parts (0.81 mol), 421.2 parts (4.05 mol) of neopentyl glycol, and 0.8 part of dibutyltin laurate were charged, and charged at 200 ° C. in the same manner as in Example 1.
And heated at the same temperature until the acid value of the contents in the kettle became 2 or less. An acid value of 1.2 was shown 5 hours after the temperature was raised at 200 ° C. Thereafter, the mixture was cooled to 120 ° C., and phthalic anhydride was obtained.
6 parts (2.43 mol), 476.3 parts (4.86 mol) of maleic anhydride, 308.7 parts (4.05 mol) of propylene glycol and 0.2 part of hydroquinone were added, and the temperature was raised to 150 ° C. The temperature was further raised from 150 ° C. to 210 ° C. over 6 hours, and the mixture was heated at the same temperature until the acid value of the content in the kettle became 40. Six hours after the temperature was raised to 210 ° C., the acid value was 38.6.
showed that. The amount of the condensed water of the reaction was 151 parts (resin X-3). Thereafter, the mixture was cooled to 100 ° C., the nitrogen gas was switched to air blowing, and glycidyl methacrylate 160.6
Part (glycidyl group / carboxyl group = 1.0, equivalent ratio)
And 0.9 parts of benzalkonium chloride,
C. and heated at the same temperature until the acid value of the contents in the kettle became 3 or less. Acryloyl-modified unsaturated polyester (A-3) showing an acid value of 1.9 in 8 hours after heating at 120 ° C
was gotten.

(4) Synthesis of unsaturated polyester (Z-1) 5SSIPA was placed in a 2 liter flask similar to that in Example 1.
169.0 parts (0.60 mol), 538.4 parts (5.61 mol) of neopentyl glycol and 0.6 part of dibutyltin laurate were charged.
And heated at the same temperature until the acid value of the contents in the kettle became 2 or less. An acid value of 1.3 was shown 3 hours after the temperature was raised at 200 ° C. Thereafter, the mixture was cooled to 120 ° C., and 279.2 parts (1.84 mol) of tetrahydrophthalic anhydride and 690.
2 parts (5.95 mol), diethylene glycol 396.
4 parts (3.74 mol) and 0.2 part of hydroquinone were added, the temperature was raised to 150 ° C, and further from 150 ° C to 200 ° C.
Until the acid value of the contents in the kettle reaches 15 at the same temperature.
Until heated. 5 hours after 200 ° C temperature rise, acid value 1
An unsaturated polyester (Z-1) having a value of 3.6 was obtained.

(5) Synthesis of acryloyl-modified unsaturated polyester (Z-2) 353.4 parts (2.33 mol) of tetrahydrophthalic anhydride and 629.3 of fumaric acid were placed in a 2 liter flask similar to that in Example 1. Parts (5.43 moles), 483.6 parts (4.65 moles) of neopentyl glycol, 328.6 parts (3.10 moles) of diethylene glycol and 0.2 part of hydroquinone, and heated to 150 ° C. while passing nitrogen gas. Temperature rising. Further, the temperature was raised from 150 ° C. to 200 ° C. in 5 hours, and heated at the same temperature until the acid value of the contents in the kettle became 45. Seven hours after the temperature was raised at 200 ° C, the acid value was 44.8, and the amount of condensed water for reaction was 208 parts (resin X-5). After that, it was cooled to 100 ° C, and the nitrogen gas was switched to air blowing.
Add 179.9 parts of glycidyl methacrylate (glycidyl group / carboxyl group = 1.0, equivalent ratio) and 1.0 part of benzalkonium chloride, raise the temperature to 120 ° C., and at the same temperature, acid value of the contents in the kettle. Was heated to 3 or less. 1
After raising the temperature by 20 ° C., an acryloyl-modified unsaturated polyester (Z-2) having an acid value of 2.6 was obtained in 12 hours.

[0027]

[Table 1]

Examples 1-5 and Comparative Examples 1-2 Photocurable resin compositions were prepared according to the components and amounts shown in Table 2, respectively. The coating film performance was evaluated, and the results are shown in Table 3.

[0029]

[Table 2]

(1) Water dilutability In a constant temperature room at 25 ° C., 5 g of the resin composition shown in Tables 2 and 3 was placed in an Erlenmeyer flask, and ion-exchanged water was gradually added. The amount of ion-exchanged water up to the generation was measured, and the results are shown in Table 3. (2) Evaluation of coating film performance First, the obtained resin composition was applied to a decorative paper-laminated plywood (10 cm × 1
5cm) with an applicator to a thickness of 500 μm.
After leaving at room temperature for 0 minutes, a high-pressure mercury lamp (output: 80 W / cm,
A 10 cm lower part of Ushio Electric Co., Ltd. was moved at a belt speed of 2 m / min and cured to form a test plate. The appearance and performance of the coating film were evaluated as follows.

(A) Appearance: The state of cracks on the surface of the coating film after light irradiation curing was observed (visually observed) and evaluated according to the following criteria. ：: no cracks Δ: one or two cracks ×: cracks on the entire surface (b) Abrasiveness: The cured surface is polished using water-resistant paper # 400, and the easiness of polishing is compared. evaluated. ：: The coating film can be sharpened even if polished lightly. ：: The polishing feels a little heavy. ×: The polishing is heavy and not polished well. (C) Pencil hardness: Use Mitsubishi Uni pencil and apply 4 on the coating surface.
The pencil hardness was the upper limit at which no scratches remained when pressed strongly at an angle of 5 °.

(D) Water resistance: The test plate was placed in warm water of 40 ° C.
It was immersed for 4 hours and the appearance was observed. ：: No abnormality ×: Whitening (e) Heat cycle property: After leaving the test plate in a constant temperature dryer at 80 ° C. for 2 hours, immediately put it in a freezer at −20 ° C. for 2 hours, and repeating this four times to obtain a coating film. The peeled state from the material (decorative plywood) was observed. ：: No abnormality △: Peeling off at one or two places ×: Peeling of all coating films

[0033]

[Table 3]

From Table 3, it can be seen that the resin composition of the present invention (Example 1)
5) have excellent coating properties even when the coating thickness is increased, and are excellent in water dilutability. On the other hand, in the resin composition using the conventional unsaturated polyester (Comparative Example 1), the abrasiveness, pencil hardness, water resistance and heat cycle property of the coating film are decoy, and 5- (sodium sulfonate) isophthalic acid is used. In the resin composition containing acryloyl-modified unsaturated polyester (Comparative Example 2) in which no is used, the water dilutability is poor.

[0035]

The hydrophilic and photocurable resin composition of the present invention can be diluted with water, and the coated film after light irradiation has high hardness, excellent durability and water resistance, and has an air atmosphere. Even if the thickness is 500 μm below, a coating film that does not generate cracks can be formed. Therefore, the resin composition of the present invention can be used in various coating fields such as ink, plastic paint, paper printing, film coating, metal coating, furniture coating, FRP lining, and also in insulating varnish, insulating sheet, laminated board, printed board in the field of electronics. , Resist ink, semiconductor encapsulant, and many other industrial fields.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09D 5/00 C09D 5/00 C 167/07 167/07

Claims (2)

[Claims] 1. An unsaturated polyester having (A) an .alpha.,. Beta.-unsaturated polybasic acid component and 5- (sodium sulfonate) isophthalic acid as essential components and having an acid value of 25 to 100, and (meth) acryloylglycidyl. Acryloyl-modified unsaturated polyester obtained by reacting the containing compound,
A hydrophilic, photocurable resin composition comprising (B) a hydrophilic polymerizable monomer and (C) a photopolymerization initiator. 2. A photopolymerization initiator (C) containing 95 to 20% by weight of component (A) based on the total amount of acryloyl-modified unsaturated polyester (A) and hydrophilic photopolymerizable monomer (B). With respect to the total amount of the components (A) and (B)
The hydrophilic and photocurable resin composition according to claim 1, which is contained in an amount of 1 to 10% by weight.