JP2001114845A - Photocurable resin composition and coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive photocurable resin composition which gives coating films holding good elongation, good breaking strength, good flexi bility, and so on, and simultaneously having high surface hardness, and to pro vide a coating. SOLUTION: This photocurable resin composition comprises (A) an unsaturated group-having urethane compound, (B) an unsaturated group-having urethane compound, and a photopoplymerization initiator. The component (A) is obtained by addition-reacting an ethylenically unsaturated compound having a hydroxy group to the same equivalent amount of a polyisocyanate. The component (B) is obtained by addition-reacting (b1) a polyisocyanate to (b2) a polyesterpolyol having a Mn of 200 to 2,500, (b3) a polyoxytetramethylene glycol having a Mn of 200 to 2,500 and (b4) an ethylenically unsaturated compound having a hydroxyl group in an isocyanate group/hydroxy group ratio of 1 equivalent/(1 to 1.1 equivalent). Therein, the total amount of the component (A) and the equivalent adduct of the components (b1) and (b2) is 3 to 15 wt.% based on the total amount of the component (A) and the component (B). And the coating comprises the photocurable resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocurable resin composition useful as a coating curable by irradiation with ultraviolet rays or electron beams, and a coating using the same. In particular, the present invention relates to a paint which is excellent in improving the surface hardness of a coating film without significantly impairing the elongation of the cured film when cured, and which can be provided at a low cost.

[0002]

2. Description of the Related Art In recent years, resin compositions curable by irradiation with ultraviolet rays or electron beams have been developed and used for coatings for coatings, adhesives, adhesives and the like. Among such resin compositions, urethane acrylates are described, for example, in JP-A-50-66596, JP-A-50-94090, JP-A-48-25095, and JP-A-64-2.
Many are known from, for example, US Pat. In recent years, for the purpose of improving productivity, use in coating applications has increased, and the required characteristics thereof have also become diverse. Above all, there is a growing demand for photocurable resin compositions and paints which have a large degree of elongation of a cured coating film, have flexibility and are excellent in curability. However, when the elongation of the cured coating film is increased by increasing the molecular weight, the surface hardness of the coating film decreases, and when the improvement of the surface hardness is prioritized, the elongation of the cured coating film decreases.

[0003]

The invention described in claims 1 to 4 provides an inexpensive photocurable resin composition having high surface hardness of a coating film while maintaining good elongation, breaking strength, flexibility and the like. Is what you do. The invention according to claim 5 has good elongation,
An object of the present invention is to provide an inexpensive paint having a high surface hardness of a coating film while maintaining the breaking strength, flexibility and the like.

[0004]

According to the present invention, an ethylenically unsaturated compound (a1) having a hydroxyl group and a compound (a2) having two or more isocyanate groups in one molecule comprise an isocyanate group of the component (a2). For one equivalent,
The urethane compound (A) having an unsaturated group added in such a ratio that the hydroxyl group of the component (a1) becomes 1 equivalent (A), 1
Isocyanate compound (b1) having two or more isocyanate groups in the molecule, having a number average molecular weight of 200 to 2500
Polyester polyol compound (b2), a polyoxytetramethylene glycol compound (b3) having a number average molecular weight of 200 to 2500 and an ethylenically unsaturated compound (b4) having a hydroxyl group to 1 equivalent of isocyanate group of component (b1). On the other hand, the total of the hydroxyl groups of the component (b2), the component (b3) and the component (b4) is 1 to 1.
A composition comprising a urethane compound (B) having an unsaturated group and a photopolymerization initiator (C) obtained by blending at an equivalent ratio and performing an addition reaction, wherein the urethane compound (B) Isocyanate groups in one molecule contained in
The compound (b1) having at least one hydroxyl group and the ethylenically unsaturated compound (b4) having a hydroxyl group are added at a ratio such that the hydroxyl group of the component (b5) is 1 equivalent to 1 equivalent of the isocyanate group of the component (b1). The total amount of the unsaturated group-containing urethane compound (b5) and the component (A) is 3 to 15 with respect to the total amount of the components (A) and (B).
Weight percent of the photocurable resin composition.

[0005] The present invention also relates to the photocurable resin composition, wherein the mole ratio of the component (b2) is larger than the mole ratio of the component (b3). The present invention also relates to the photocurable resin composition, wherein the proportion of the photopolymerization initiator (C) is 1 to 10% by weight based on the total amount of the components (A) and (B). The present invention also relates to the photocurable resin composition, wherein the polyester polyol compound is obtained by reacting a dihydric alcohol with a dibasic acid. Also, the present invention
The present invention relates to a paint containing the photocurable resin composition.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The component (A) in the present invention is obtained by mixing a mixture containing the components (a1) and (a2) with (a)
2) With respect to 1 equivalent of isocyanate group of component, (a1)
It is obtained by carrying out an addition reaction at a ratio such that the hydroxyl group of the component becomes 1 to 1.1 equivalent. When the hydroxyl group of the component (a1) is less than 1 equivalent to 1 equivalent of the isocyanate group of the component (a2), the storage stability of the obtained photocurable resin composition is inferior, and the resin composition gels. When it exceeds 1 equivalent, the balance of physical properties of a cured coating film of the obtained photocurable resin composition is inferior.

The component (A) in the present invention comprises the component (a)
The component (1) and the component (a2) can be obtained by mixing the components in the above ratio and performing an addition reaction (urethane-forming reaction).
The component (a1) and the component (a2) can be obtained by mixing the components in the above ratio and heating at 70 to 80 ° C. for 5 to 12 hours. At that time, a reaction catalyst such as an organic solvent and dibutyltin dilaurate can be used as needed. Examples of the organic solvent include ester, ketone, and aromatic organic solvents.Examples of the ester organic solvent include butyl acetate, ethyl acetate, and methyl acetate. Examples of the organic solvent include diethyl ketone, methyl ethyl ketone, and methyl isobutyl ketone, and examples of the aromatic organic solvent include toluene and xylene. When these organic solvents are used, they are used alone or in combination of two or more.

The ethylenically unsaturated compound (a1) having a hydroxyl group in the present invention includes, for example, hydroxyalkyl acrylate and hydroxyalkyl methacrylate having an alkyl group having 2 to 7 carbon atoms, and specific examples thereof. As 2-hydroxyethyl (meth) acrylate ((meth) acrylate refers to acrylate and methacrylate; the same applies hereinafter),
2-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, N-methylol (meth) acrylamide, and the like. Can be Further, as the component (a1), ε-
A compound having a hydroxyl group and an ethylenically unsaturated double bond obtained by ring-opening polymerization of a caprolactone monomer is also included. These components (a1) may be used alone or
Although used in combination of more than one type, there is no uncured feeling on the surface of the obtained cured product, and from the point of extremely excellent curability,
2-hydroxyethyl acrylate is preferred.

The compound (a2) having two or more isocyanate groups in one molecule in the present invention includes, for example,
Examples include diisocyanate compounds such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, tetramethyl xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, and hydrogenated products thereof. Among these compounds, xylylene diisocyanate, methyl xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, trimethyl hexamethylene diisocyanate, tetramethyl xylylene diisocyanate, and norbornene diisocyanate are preferred from the viewpoint of excellent workability. The component (a2) is used alone or in combination of two or more.

The component (B) in the present invention comprises the component (b)
The mixture containing the components (1) to (b4) is mixed with the component (b2),
3) The sum of the hydroxyl groups of the component and the component (b4) is 1
It is a mixture of a urethane compound having an unsaturated group, which is obtained by blending at a ratio of ~ 1.1 equivalents and performing an addition reaction.
(B1) 1 equivalent of isocyanate group of the component
If the total of the hydroxyl groups of the component (2), the component (b3) and the component (b4) is less than 1 equivalent, the resulting photocurable resin composition has poor storage properties and the resin composition gels.
When it exceeds 1 equivalent, the balance of the cured coating film properties of the photocurable resin composition obtained is poor. Further, it is preferable that the compounding mole number of the component (b2) is larger than the compounding mole number of the component (b3), and if the compounding mole number of the component (b2) is smaller than the compounding mole number of the component (b3), the obtained photocuring will be obtained. In the curable resin composition, the balance of physical properties of the cured coating film tends to be inferior.

Specific examples of the component (b1) used in the synthesis of the component (B) include the same as the specific examples of the component (a2), and specific examples of the component (b4) include the components (a1) The same as the specific examples of the components can be mentioned.

In the present invention, the number average molecular weight is 200 to 2
As the polyester polyol compound (b2) of 500, for example, various commercially available polyester polyol compounds can be used, but a dihydric alcohol and a dibasic acid are reacted from the viewpoint of excellent flexibility of the obtained cured product. Compounds obtained by the above method are preferred.

Examples of the dihydric alcohol used in the synthesis of the compound (b2) include (polyoxy) ethylene glycol, (polyoxy) propylene glycol, (polyoxy) tetramethylene glycol and polyoxyethylene polyoxypropylene alkyl ether type. Glycol-compounds such as 1,9-nonanediol and 2-methyl-1,8-octanediol; 3-methyl-1,5
-Pentanediol, 1,3-butylene glycol,
1,6-hexanediol, neopentyl glycol,
Glycols such as hydrogenated bisphenol A and bisphenol dihydroxypropyl ether are exemplified.

[0014] Further, 2 used in the synthesis of the component (b2)
As the basic acid, for example, phthalic anhydride, isophthalic acid, terephthalic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, Examples include heptonic anhydride, hymic anhydride, maleic anhydride, fumaric acid, and itaconic acid.

These dihydric alcohols and dibasic acids can be subjected to an esterification reaction alone or in combination of two or more to obtain the component (b2). This (b
2) The component can be obtained, for example, by reacting 3-methyl-1,5-pentanediol with isophthalic acid.
298 parts by weight and 913 parts by weight of isophthalic acid are mixed,
It can be obtained by heating at 220 to 250 ° C. to remove condensation water from the reaction system.

The number average molecular weight of the component (b2) obtained is
From the viewpoint of the flexibility of the obtained cured product (film), that is, the balance between the elongation of the cured product and the properties of the obtained coating material, it is set to 200 to 2500, preferably 500 to 2500. Component (b2) has a number average molecular weight of 200
If less than, the elongation of the obtained cured product becomes insufficient,
On the other hand, when the viscosity exceeds 2,500, the viscosity of the obtained photocurable resin composition increases remarkably, so that the workability at the time of coating is reduced, and the hardness and strength of the obtained cured product become insufficient. . The number average molecular weight in the present invention is a value measured by a gel permeation chromatography method and determined using a standard polystyrene calibration curve.

In the present invention, the number average molecular weight of the polyoxytetramethylene glycol compound (b3) is
2) Similarly to the component, from the viewpoint of the flexibility of the obtained cured product (film), that is, the balance between the elongation of the cured product and the properties of the obtained paint, it is set to 200 to 2500,
It is preferably from 0 to 2500. If the number average molecular weight of the component (b3) is less than 200, the resulting cured product will have insufficient elongation, while if it exceeds 2500, the viscosity of the resulting photocurable resin composition will increase significantly, The workability at the time of coating is reduced, and the hardness and strength of the obtained cured product are insufficient.

The photopolymerization initiator (C) in the present invention includes, for example, a carbonyl-based photopolymerization initiator, a sulfide-based photopolymerization initiator, a quinone-based photopolymerization initiator, an azo-based photopolymerization initiator, and a sulfochloride-based photopolymerization initiator. Examples thereof include a polymerization initiator, a thioxanthone-based photopolymerization initiator, a peroxide-based photopolymerization initiator, and isoamyl o-dimethylaminobenzoate.

Examples of the carbonyl-based photopolymerization initiator include benzophenone, diacetyl, benzyl, benzoin, ω-bromoacetophenone, chloroacetone, acetophenone, 2,2-diethoxyacetophenone,
2,2-dimethoxy-2-phenylacetophenone, p
-Dimethylaminoacetophenone, p-dimethylaminopropiophenone, 2-chlorobenzophenone, p,
p'-dichlorobenzophenone, p, p'-bisdiethylaminobenzophenone, Michler's ketone, benzoin methyl ether, benzoin isobutyl ether, benzoin-n-butyl ether, benzyldimethyl ketal, 1-hydroxycyclohexylphenyl ketone, 2
-Hydroxy-2-methyl-1-phenylpropane-1
-One, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, methylbenzoyl formate, 2,2-diethoxyacetophenone,
4-N, N'-dimethylacetophenone and the like.

Examples of the sulfide-based photopolymerization initiator include diphenyl disulfide, dibenzyl disulfide, tetraethylthiuram disulfide, tetramethylammonium monosulfide and the like. Examples of the quinone-based photopolymerization initiator include benzoquinone and anthraquinone. Examples of the azo-based photopolymerization initiator include azobisisobutyronitrile, 2,2-azobispropane, hydrazine and the like. Examples of the thioxanthone-based photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, and the like. Examples of the peroxide-based photopolymerization initiator include benzoyl peroxide, di-tert-butyl peroxide and the like. These photopolymerization initiators are used alone or in combination of two or more.

The mixing ratio of the components (A) and (B)
In view of the balance between the properties (viscosity, molecular weight, etc.) of the obtained resin and the properties (curability, flexibility (elongation, etc.)) of the cured product (coating film), the total amount of the components (A) and (b5) is ,
The proportion is preferably 3 to 15% by weight, more preferably 4 to 15% by weight, preferably 5 to 15% by weight, based on the total amount of the components (A) and (B). It is more preferable to set the ratio such that When the total amount of the component (A) and the component (b5) is less than 3% by weight, the surface hardness of the obtained cured product is insufficient, and an uncured feeling remains.
If it exceeds 5% by weight, thixotropic properties appear in the resin, handling properties are reduced, and the flexibility of the obtained cured product is sharply reduced.

A urethane compound having an unsaturated group in which the hydroxyl group of the component (b4) is added in an equivalent ratio of 1 equivalent to the isocyanate group of the component (b1) contained in the component (B) ( b5) corresponds to the above-mentioned component (A), and can be used by synthesizing the component (B) such that a necessary amount is present in the component (B) when synthesizing the component (B). That is, the synthesis may be performed so that the component (b5) is 3 to 15% by weight based on the total amount of the components (A) and (B).
Further, a separately synthesized component (A) is added to the component (B),
The total amount of the components (A) and (b5) may be 3 to 15% by weight based on the total amount of the components (A) and (B).

The component (A) and the component (b5) are compounds that exhibit the same function in the photocurable resin composition of the present invention. Therefore, both components are present in the photocurable resin composition of the present invention. Complementary, the proportion of the urethane compound (A) is 0 to 15% by weight and the proportion of the urethane compound (b5) is 0 to 15% by weight based on the total amount of the urethane compound (A) and the urethane compound (B). % By weight. In the present invention, the weight percentage of the total amount of the component (A) and the component (b5) in the total amount of the component (b5) and the component (A) and the component (B) in the component (B) is gel permeation. It can be measured by a chromatography method and can be determined from the area.

The mixing ratio of the component (C) is determined based on the balance between the photocurability and the properties (curability, flexibility (elongation), adhesion, etc.) of the obtained cured product. The content is preferably 1 to 10% by weight, more preferably 3 to 5% by weight, based on the total amount of the components. If the compounding ratio is less than 1% by weight, photocuring tends to be insufficient, and if it exceeds 10% by weight, the properties (curability, flexibility (elongation), etc.) of the obtained cured product are generally poor. Tend to decrease.

The photocurable resin composition of the present invention contains, as necessary, a photopolymerizable monomer having at least one unsaturated double bond capable of photocuring in one molecule within a range not to deteriorate its properties. They may be used alone or in combination of two or more. As the photopolymerizable monomer, a monofunctional or polyfunctional acrylate compound or the like can be preferably used.

Of these, (meth) acrylate compounds having an acryloyl group or a methacryloyl group are preferred, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate. Acrylate, tert-butyl (meth) acrylate, isobutyl (meth) acrylate, ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, n-hexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, tridecyl ( Meth) acrylates,
Ethoxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, glycidyl (meth) acrylate, butoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-methoxyethoxy ( (Meth) acrylate, 2-ethoxyethoxyethyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, octafluoropentyl (meth) acrylate, N, N-dimethyl Aminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, allyl (meth) acrylate, 1,
3-butanediol (meth) acrylate, 1,4-butanediol (meth) acrylate, (meth) acryloylmorpholine, 1,6-hexanediol (meth)
Acrylate, polyethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate,
Triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, hydroxypivalic acid ester neopentyl glycol di (meth) acrylate, trimethylolpropane di (meth)
Acrylate, 1,3-bis (hydroxyethyl)-
5,5-dimethylhydantoin, 3-methylpentanediol (meth) acrylate, α, ω-di (meth) acrylic bisdiethylene glycol phthalate, trimethylolpropane tri (meth) acrylate, pentaerythritol (meth) acrylate, pentaerythritol Hexa (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, α, ω-tetraallylbistrimethylolpropane tetrahydrophthalate, 2-hydroxyethyl (meth) acryloyl phosphate, trimethylolpropane tri (meth) acrylate, Ethylene glycol (meth) acrylate,
Tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4
-Butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, diacryloxyethyl phosphate, N-vinylpyrrolidone, N-
And vinylcaprolactam. Of these, (meth) acrylate derivatives are preferred.

The photocurable resin composition of the present invention can be used for a paint. In that case, if necessary, the photocurable resin composition of the present invention may contain a natural or synthetic polymer, a filler, an extender, a pigment, a polymerization inhibitor, a leveling agent, a modifier, a plasticizer, an organic solvent, and the like. Can be added.

Examples of the natural polymer include oils and fats, and examples of the oils and fats include linseed oil, tung oil, soybean oil, castor oil, and epoxidized oil. For example, unsaturated polyester resins, vinyl ester resins, vinyl urethane resins, vinyl ester urethane resins, polyisocyanates, polyepoxides, epoxy-terminated polyoxazolidones, acrylic resins, alkyd resins, urea resins, melamine resins,
Polydiene elastomers, saturated polyesters, saturated polyethers, cellulose derivatives, epoxidized oils and the like can be mentioned. Examples of the cellulose derivative include nitrocellulose and cellulose acetate butyrate. Examples of the filler and extender include calcium carbonate, talc, mica, clay, silica powder, colloidal silica, barium sulfate, aluminum hydroxide, zinc stearate and the like. Examples of the pigment include zinc white, red iron, azo pigment and the like.

Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, benzoquinone, p-tert-butyl carbitol, 2,6-di-tert.
-Butyl-4-methylphenol and the like. Examples of the leveling agent include a polyether-modified dimethylpolysiloxane copolymer, a polyester-modified dimethylpolysiloxane copolymer, a polyether-modified methylalkylpolysiloxane copolymer, and an aralkyl-modified methylalkylpolysiloxane copolymer. .

Examples of the plasticizer include dihydric alcohol ester plasticizers, other ester plasticizers, epoxy plasticizers, polyester plasticizers, and the like. Examples of the dihydric alcohol ester plasticizer include: , Diethylene glycol dibenzoate, triethylene glycol-di-2-ethyl butyrate, and the like. Examples of other ester plasticizers include, for example, tributyl phosphate, triphenyl phosphate, tri-2-ethylhexyl phosphate, adipine Dibutyl acid, di-n-hexyl adipate, di-2-ethylhexyl azelate, dibutyl sebacate, dioctyl sebacate, diethyl phthalate,
Examples thereof include dibutyl phthalate, di-n-octyl phthalate, and butyl oleate. Examples of the organic solvent include those exemplified as the organic solvent used to obtain the component (A).

The mixing ratio of the above-mentioned natural or synthetic polymer, filler, extender, pigment, polymerization inhibitor, leveling agent, modifier and plasticizer is appropriately selected depending on the use of the paint to be obtained. However, the total amount of these components is preferably 70% by weight or less based on the weight of the paint. In addition, the compounding ratio of the photopolymerizable monomer having one or more photocurable unsaturated double bonds in one molecule and the compounding ratio of the organic solvent are appropriately selected depending on the use of the obtained paint, and are particularly limited. However, it is preferable that each is 50% by weight or less based on the weight of the paint.

As a method of forming a coating, known methods such as a paint shaker method, a roll mill method, a sand mill method, a disperser method, a kneader method, and a high-speed impeller mill method can be used. The paint of the present invention can be applied for painting according to a usual painting method. For coating, for example, an air spray method, an airless sprayer, an electrostatic coater, a dipping, a roll coater, a brush, or the like can be used.

The paint of the present invention has excellent curability,
It can be used for painting metal materials such as iron and aluminum, calcium silicate board, pulp cement board, lightweight concrete board, asbestos cement board, inorganic building materials such as mortar, wood, paper, plastic base materials, etc. The coating film can be cured by irradiating the coating film with ultraviolet rays using a metal halide lamp or the like as a light source.

[0034]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the following, "parts" and "%"
All are by weight unless otherwise noted.

Production Example 1 (Urethane acrylate compound
1) After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, tolylene diisocyanate (Coronate T-8, manufactured by Nippon Polyurethane Co., Ltd.)
0) 174 parts, 100 parts of butyl acetate were charged, and the temperature was raised to 70 ° C, and kept at 70 to 75 ° C, 238 parts of 2-hydroxyethyl acrylate (2-HEA), 0.2 parts of hydroquinone monomethyl ether, and dibutyltin dilaurate ( A mixed liquid of 0.4 part of L101 (manufactured by Tokyo Fine Chemical Co., Ltd.) and 128 parts of butyl acetate was uniformly dropped over 3 hours to carry out a reaction. When the reaction was continued for about 5 hours after the completion of the dropping, the reaction was terminated after confirming that the isocyanate had disappeared as a result of IR measurement. The solid content obtained by adding 2-hydroxyethyl acrylate to both ends of tolylene diisocyanate was about 7 hours.
0% urethane acrylate compound was obtained.

Production Example 2 (Urethane acrylate compound
2) After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 232 parts of 2-hydroxyethyl acrylate (2-HEA), 3-methyl-1,5-pentane Polyester diol obtained by reacting diol with isophthalic acid to make polyester (Kuraray Co., Ltd., Kuraray polyol P2030, molecular weight about 2036)
4886 parts, polyoxytetramethylene glycol (B
ASF, PolyTHF250, molecular weight about 250) 28
8 parts, hydroquinone monomethyl ether 3 parts, dibutyltin dilaurate (manufactured by Tokyo Fine Chemical Co., Ltd., L10
1) 5 parts, xylene 1448 parts and butyl acetate 1000
The mixture was heated to 70 ° C. and kept at 70 to 75 ° C., and isophorone diisocyanate (manufactured by Huls Japan,
VESTANAT IPDI) 400 parts, tolylene diisocyanate (Nippon Polyurethane Co., Ltd., Coronate T-
80) A mixed liquid of 470 parts of butyl acetate and 931 parts of butyl acetate was uniformly dropped over 3 hours to carry out a reaction. When the reaction was carried out for about 5 hours after the completion of the dropping, IR measurement confirmed that the isocyanate had disappeared, and the reaction was terminated. Thus, a urethane acrylate compound having a solid content of about 65% and a number average molecular weight of about 5600 was obtained.

Production Example 3 (Urethane acrylate compound
3) After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 232 parts of 2-hydroxyethyl acrylate (2-HEA), 3-methyl-1,5-pentane Polyester diol obtained by reacting diol with isophthalic acid to make polyester (Kuraray Co., Ltd., Kuraray polyol P2030, molecular weight about 2036)
4886 parts, polyoxytetramethylene glycol (manufactured by Hodogaya Chemical Industry Co., Ltd., PTG650SN, molecular weight about 68)
7) 790 parts, hydroquinone monomethyl ether 3
Parts, 7 parts of dibutyltin dilaurate (manufactured by Tokyo Fine Chemical Co., L101), 1567 parts of xylene, and 1000 parts of butyl acetate were charged, heated to 70 ° C., kept at 70 to 75 ° C., and isophorone diisocyanate (manufactured by Huls Japan Co., Ltd.). A mixed liquid of 400 parts of VESTANAT IPDI), 470 parts of tolylene diisocyanate (manufactured by Nippon Polyurethane Co., Coronate T-80), and 1087 parts of butyl acetate was uniformly dropped over 3 hours to carry out a reaction. When the reaction was carried out for about 5 hours after the completion of the dropwise addition, IR measurement confirmed that the isocyanate had disappeared, and the reaction was terminated. Thus, a urethane acrylate compound having a solid content of about 65% and a number average molecular weight of about 6,700 was obtained.

Production Example 4 (Urethane acrylate compound
4) After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 232 parts of 2-hydroxyethyl acrylate (2-HEA), 3-methyl-1,5-pentane Polyester diol obtained by reacting diol with isophthalic acid to make polyester (Kuraray Co., Ltd., Kuraray polyol P2030, molecular weight about 2036)
4886 parts, polyoxytetramethylene glycol (manufactured by Hodogaya Chemical Industry Co., Ltd., PTG1000SN, molecular weight: about 10
00) 1150 parts, hydroquinone monomethyl ether 4 parts, dibutyl tin dilaurate (Tokyo Fine Chemicals Co., Ltd., L101) 7 parts, xylene 1650 parts and butyl acetate 1000 parts were charged, and the temperature was raised to 70 ° C. 400 parts of forone diisocyanate (Vestanat IPDI, manufactured by Huls Japan)
A mixed liquid of 470 parts of tolylene diisocyanate (manufactured by Nippon Polyurethane Co., Coronate T-80) and 1200 parts of butyl acetate was uniformly dropped over 3 hours to carry out a reaction. When the reaction was carried out for about 5 hours after the completion of the dropwise addition, the reaction was terminated after confirming that the isocyanate had disappeared as a result of IR measurement, and a urethane acrylate compound having a solid content of about 65% and a number average molecular weight of about 6100 was obtained.

Production Example 5 (Urethane acrylate compound
5) After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 480 parts of 2-hydroxyethyl acrylate (2-HEA), 3-methyl-1,5-pentane Polyester diol obtained by reacting diol with isophthalic acid to make polyester (Kuraray Co., Ltd., Kuraray polyol P2030, molecular weight about 2036)
4886 parts, polyoxytetramethylene glycol (manufactured by Hodogaya Chemical Industry Co., Ltd., PTG850SN, molecular weight: about 86
8) 998 parts, hydroquinone monomethyl ether 4
Parts, 7 parts of dibutyltin dilaurate (manufactured by Tokyo Fine Chemical Co., Ltd., L101), 1715 parts of xylene and 1000 parts of butyl acetate were heated to 70 ° C., heated to 70 to 75 ° C., and isophorone diisocyanate (manufactured by Huls Japan Co., Ltd.). A mixed liquid of 400 parts of VESTANAT IPDI), 656 parts of tolylene diisocyanate (manufactured by Nippon Polyurethane Co., Coronate T-80) and 1287 parts of butyl acetate was uniformly dropped over 3 hours to carry out a reaction. When the reaction was allowed to proceed for about 5 hours after the completion of the dropwise addition, IR measurement confirmed that the isocyanate had disappeared, and the reaction was terminated. Thus, a urethane acrylate compound having a solid content of about 65% and a number average molecular weight of about 5000 was obtained.

Production Example 6 (Urethane acrylate compound
6: Comparative compound) After introducing air gas into a reaction vessel equipped with a stirrer, a thermometer, a cooling pipe, and an air gas introduction pipe, 232 parts of 2-hydroxyethyl acrylate (2-HEA), diethylene glycol (Nisso Maruzen Chemical) (DEGAL) 12
2 parts, 4886 parts of polyester diol (Kuraray, Kuraray polyol P2030, molecular weight: about 2036) made by reacting 3-methyl-1,5-pentanediol with isophthalic acid, 3 parts of hydroquinone monomethyl ether, dibutyltin dilaurate ( 6 parts of Tokyo Fine Chemical Co., Ltd., L101) and butyl acetate 1804
The mixture was heated to 70 ° C. and kept at 70 to 75 ° C., and isophorone diisocyanate (manufactured by Huls Japan,
VESTANAT IPDI) 400 parts, tolylene diisocyanate (Nippon Polyurethane Co., Ltd., Coronate T-
80) A mixed liquid of 470 parts and 774 parts of butyl acetate was uniformly dropped in 3 hours to carry out a reaction. When the reaction was allowed to proceed for about 5 hours after the completion of the dropwise addition, IR measurement confirmed that the isocyanate had disappeared, and the reaction was terminated. Thus, a urethane acrylate compound having a solid content of about 70% and a number average molecular weight of about 6,300 was obtained.

Production Example 7 (Urethane acrylate compound
7: Comparative compound) After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 1427 parts of 2-hydroxyethyl acrylate (2-HEA), diethylene glycol (Nisso Maruzen Chemical) (DEGAL) 1
22 parts, 4886 parts of polyester diol (Kuraray Co., Ltd., Kuraray polyol P2030, molecular weight about 2036) polyesterified by reacting 3-methyl-1,5-pentanediol with isophthalic acid, 5 parts of hydroquinone monomethyl ether, dibutyltin dilaurate ( Tokyo Fine Chemical Company, L101) 10 parts, xylene 1724
Parts and 1100 parts of butyl acetate, and after heating to 70 ° C., 7
The temperature is kept at 0 to 75 ° C., and isophorone diisocyanate (VESTANAT IPD manufactured by Huls Japan) is used.
I) A mixed liquid of 400 parts, 1366 parts of tolylene diisocyanate (manufactured by Nippon Polyurethane Co., Coronate T-80), and 1493 parts of butyl acetate was uniformly dropped over 3 hours to carry out a reaction. When the reaction was carried out for about 5 hours after completion of the dropwise addition, the reaction was terminated after confirming that the isocyanate had disappeared as a result of IR measurement. The solid content was about 65%, and the number average molecular weight was about 2,000.
Was obtained.

Table 1 shows the number of moles used in Production Examples 1 to 7.

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[Table 1]

Example 1 The urethane acrylate compound obtained in Production Example 1 was blended in an amount of 5% by weight based on the urethane acrylate compound obtained in Production Example 2, and benzyl dimethyl ketal (a photopolymerization initiator) was added to this mixture. BD manufactured by Daiichi Kogyo Seiyaku
The photocurable resin composition was prepared by blending 3% by weight of K) with the above mixture and uniformly mixing.

Example 2 The urethane acrylate compound obtained in Production Example 1 was blended in an amount of 5% by weight based on the urethane acrylate compound obtained in Production Example 3, and benzyl dimethyl ketal (a photopolymerization initiator) was added to this mixture. BD manufactured by Daiichi Kogyo Seiyaku
The photocurable resin composition was prepared by blending 3% by weight of K) with the above mixture and uniformly mixing.

Example 3 The urethane acrylate compound obtained in Production Example 1 was blended in an amount of 5% by weight based on the urethane acrylate compound obtained in Production Example 4, and benzyl dimethyl ketal (a photopolymerization initiator) was added to this mixture. BD manufactured by Daiichi Kogyo Seiyaku
The photocurable resin composition was prepared by blending 3% by weight of K) with the above mixture and uniformly mixing.

Example 4 To the urethane acrylate compound obtained in Production Example 5, benzyldimethyl ketal (BDK, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a photopolymerization initiator was blended at 3% by weight based on the urethane acrylate compound, and the mixture was uniformly mixed. To prepare a photocurable resin composition.

Comparative Examples 1 and 2 To the urethane acrylate compounds obtained in Production Examples 6 and 7, benzyl dimethyl ketal (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., BDK) was added as a photopolymerization initiator to the urethane acrylate compound. The photo-curable resin composition was prepared by blending by weight and uniformly mixing.

Comparative Example 3 The urethane acrylate compound obtained in Production Example 4 was mixed with benzyldimethyl ketal (BDK, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a photopolymerization initiator in an amount of 3% by weight based on the urethane acrylate compound. To prepare a photocurable resin composition.

Application Examples In order to measure the elongation and tensile strength of a cured coating film,
The photocurable resin composition obtained in each of the Examples and Comparative Examples was applied to a glass plate using an applicator to a thickness of 150 μm.
After the coating, it was dried in a hot air drier heated to 60 ° C. for about 10 minutes to evaporate the organic solvent, and then was irradiated with an ultraviolet irradiation device (6 kW, two 80 w / cm high-pressure mercury lamps, a UV irradiation device;
Nippon Battery Co., Ltd.), one 80 w / cm high pressure mercury lamp, irradiation distance 15 cm, conveyor speed 5 m / min.
mJ / cm ² ) to obtain a cured film having a thickness of about 60 μm. Various performance tests were performed on the coating films thus obtained. The results are shown in Table 2 together with the properties of the resin composition before curing.

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[Table 2]

(1) Thixotropy: A thixoindex was measured in accordance with JIS K5400, and evaluation was made from the value. No thixotropic property ≦ 1.5 <Thixotropic property (2) Number average molecular weight: The adjusted photocurable resin composition was measured by gel permeation chromatography, and determined using a standard polystyrene calibration curve. (3) Ratio of (A) + (b5) components: The adjusted photocurable resin composition was measured by gel permeation chromatography, and determined from the area of each component.

(4) Surface hardness: A 50 mm square gauze (specified by the Japanese Pharmacopoeia) is placed on the coating film, and a cylindrical weight having a diameter of 40 mm, a mass of 500 g and a flat bottom is placed at the center of the gauze. The gauze was separated from the coating film after being placed and left at room temperature for 18 hours or more, and evaluated by the degree of the network pattern of the gauze attached to the coating film. 1: The mesh remains clearly 2: The mesh remains 3: The mesh remains a little 4: The mesh hardly remains 5: The mesh does not exist at all

(5) Elongation and tensile strength of cured film:
The cured film has a length of 5 at the ambient temperature of 20 ° C and -20 ° C.
Cut into strips of 0 mm and width of 15 mm, test span 50
mm, and at a temperature of 20 ° C. and −20 ° C., at a pulling speed of 50 mm / min until the cured film breaks in a one-piece / two-piece refrigerator high-temperature bath (manufactured by Shimadzu Corporation). The elongation at break (mm) and the strength (N) were used to calculate the calculated elongation (%) and tensile strength from the following formulas. Elongation (%) = [Elongation at break (mm) / Test span (mm)] × 100 Tensile strength (N / cm ² ) = [Strength at break (N) / (A ×
B)] A: Width (cm) of cured film specimen B: Thickness (cm) of cured film specimen

According to Table 2, the photocurable resin compositions obtained in Comparative Examples 1 and 3 both had an evaluation result of "1" in the surface hardness column, and were extremely inferior in curing feeling. On the other hand, the photocurable resin composition obtained in Comparative Example 2 has an excellent evaluation result of “5” in the surface hardness column, but has an evaluation result of “thixotropy” in the thixotropic column of the resin characteristics. And the handling of the resin was inferior. Further, the evaluation result in the elongation percentage column of the cured coating film is less than “100%” at 20 ° C., and it cannot be said that the film has sufficient flexibility. On the other hand, according to Table 2, the photocurable resin compositions obtained in Examples 1 to 4 were evaluated as “3” or “4” in the surface hardness column, and were excellent in surface hardness. The evaluation results in the elongation percentage column of the cured coating film also showed that the film had good flexibility of 20% or more at 200% or more, and also had good tensile strength and good strength regardless of temperature. In addition, the photocurable resin compositions obtained in Examples 1 to 4 exhibited good cured coating film properties irrespective of the method of synthesizing the photocurable resin composition, and also had good resin handling properties. .

[0056]

The photocurable resin compositions according to claims 1 to 4 are inexpensive and have high surface hardness of the coating film while maintaining good elongation, breaking strength, flexibility and the like. The coating material according to the fifth aspect is a low-cost coating material having a high surface hardness of a coating film while maintaining good elongation, breaking strength, flexibility and the like.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 4J027 AC03 AC06 AG03 AG04 AG12 AG23 AG24 BA07 BA08 BA12 BA13 BA15 BA16 BA20 BA25 BA26 BA28 CB09 CB10 CC05 CD08 4J038 FA281 FA282 KA03 MA14 NA11 PA17 PC02 PC04 PC07 PC08 PC10

Claims (5)

[Claims] 1. An ethylenically unsaturated compound (a1) having a hydroxyl group and a compound (a2) having two or more isocyanate groups in one molecule are represented by the following formula: (a1) A) a urethane compound having an unsaturated group added in such a manner that the hydroxyl group of the component becomes 1 equivalent (A), an isocyanate compound having two or more isocyanate groups in one molecule (b1), and a number average molecular weight of 200 to 2500 polyester polyol compound (b2), polyoxytetramethylene glycol compound having a number average molecular weight of 200 to 2500 (b3) and ethylenically unsaturated compound having a hydroxyl group (b4)
With respect to 1 equivalent of isocyanate group of component (b1)
The urethane compound (B) having an unsaturated group obtained by blending the components (b2), (b3) and (b4) in a ratio such that the total of the hydroxyl groups thereof is 1 to 1.1 equivalents and performing an addition reaction; A composition comprising a photopolymerization initiator (C), wherein the compound (b1) has two or more isocyanate groups in one molecule contained in the urethane compound (B)
And an ethylenically unsaturated compound having a hydroxyl group (b
Urethane compound (b) having an unsaturated group in which the hydroxyl group of component (b4) is added in an amount of 1 equivalent to 1 equivalent of isocyanate group of component (b1).
5) and the total amount of the components (A) is (A) and (B)
A photocurable resin composition which is 3 to 15% by weight based on the total amount of the components. 2. The photocurable resin composition according to claim 1, wherein the amount of the component (b2) is greater than the amount of the component (b3). 3. The photocurable resin composition according to claim 1, wherein the proportion of the photopolymerization initiator (C) is 1 to 10% by weight based on the total amount of the components (A) and (B). object. 4. The photocurable resin composition according to claim 1, wherein the polyester polyol compound is obtained by reacting a dihydric alcohol with a dibasic acid. 5. A coating comprising the photocurable resin composition according to claim 1, 2, 3, or 4.