JPH1095822A - Photo-setting resin composition and coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photo-setting resin composition excellent in curability and suitable for a coating material and provide a coating material. SOLUTION: This composition contains a polymer (A) obtained by the addition reaction of a blend of a polycarbonate-diol compound (a1), a hydroxylated ethylenically unsaturated compound (a2) and a compound (a3) having at least two isocyanate groups in the molecule at an equivalent ratio of the hydroxyl groups of component (a1) to the isocyanate groups of component (a3) of (0.5 to 0.75):1, an equivalent ratio of the hydroxyl groups of component (a2) to the isocyanate groups of component (a3) of (0.25 to 0.5):1, and an equivalent ratio of the total hydroxyl groups of components (a1) and (a2) to the isocyanate groups of component (a3) of (1 to 1.1):1, an ethylenically unsaturated compound (B) having at least three ethylenic bonds in the molecule, and a photopolymerization initiator (C). The coating material contains this composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a photocurable resin composition and a paint.

[0002]

2. Description of the Related Art In recent years, many resin compositions curable by irradiation with ultraviolet rays or electron beams have been developed and used for paints, adhesives, adhesives and the like. As such a resin composition, a urethane-modified acrylate resin composition having a polycarbonate skeleton of methyloctanediol / nonanediol in a polyurethane skeleton is known (Japanese Patent Application Laid-Open No. Sho 64).
-24817 publication). This resin composition is excellent in hydrolysis resistance and weather resistance, and also has a high elongation, flexibility, elasticity,
It has adhesiveness and adhesiveness. However, when the urethane-modified acrylate obtained using the blending ratio disclosed in this publication is used, the obtained resin composition is
Curability was not sufficient.

[0003]

The object of the present invention is to provide a photocurable resin composition which has excellent curability and is suitable for a coating material. The invention described in claim 2 is claim 1
In addition to the effects of the invention described above, the obtained cured product has excellent flexibility and provides a photocurable resin composition suitable for a coating material. The third aspect of the present invention provides a photocurable resin composition suitable for a coating material having low viscosity and excellent workability, in addition to the effects of the first or second aspect of the present invention. Claim 4
The described invention provides a paint having excellent curability.

[0004]

Means for Solving the Problems The present invention provides the following (1) to
Regarding (4). (1) (A) (a1) a polycarbonate diol compound, (a2) an ethylenically unsaturated compound having a hydroxyl group, and (a3) a compound having two or more isocyanate groups in one molecule, the isocyanate group of the component (a3) The amount of the hydroxyl group of the component (a1) is 0.1 to 1 equivalent.
5 to 0.75 equivalents, the hydroxyl group of the component (a2) becomes 0.25 to 0.5 equivalents, and the components (a1) and (a)
2) a polymer obtained by blending the components in a proportion such that the total of the hydroxyl groups of the component is 1 to 1.1 equivalents and performing an addition reaction, (B) having three or more ethylenically unsaturated double bonds in one molecule A photocurable resin composition comprising an ethylenically unsaturated compound and (C) a photopolymerization initiator.

(2) (a1) The polycarbonate diol compound is 1,9-nonanediol, 2-methyl-1,
The photocurable resin composition according to the above (1), which is a compound obtained by reacting 8-octanediol and diphenyl carbonate. (3) (a3) The photocurable resin composition according to the above (1) or (2), wherein the compound having two or more isocyanate groups in one molecule is isophorone diisocyanate. (4) A paint containing the photocurable resin composition according to any one of (1) to (3).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As the polycarbonate diol compound (a1) in the present invention, various commercially available polycarbonate diol compounds can be used, for example. Formula (I)

Embedded image (Wherein R ¹ and R ² are each independently

Embedded image Or

Embedded image And a plurality of R ¹ may be the same or different,
n is an integer of 7 to 25).

This compound can be obtained, for example, by reacting 1,9-nonanediol, 2-methyl-1,8-octanediol and diphenyl carbonate. 870 parts by weight, 2
-Methyl-1,8-octanediol in an amount of 870 parts by weight and diphenyl carbonate in an amount of 2140 parts by weight;
It can be obtained by heating at 90 to 210 ° C. to remove phenol from the reaction system. The component (a1) is used alone or in combination of two or more.

The number average molecular weight of the component (a1) obtained is
From the viewpoint of the balance between the flexibility of the obtained cured product (film), that is, the elongation of the cured product, and the properties of the obtained paint, 100
0 to 3000, preferably 1500 to 250
More preferably, it is 0. When the number average molecular weight of the component (a1) is less than 1,000, the resulting cured product tends to have insufficient elongation.
The viscosity of the obtained photocurable resin composition is significantly increased, and therefore, the workability when forming a coating material is reduced, and the hardness and strength of the obtained cured product are insufficient, or the tack on the surface of the cured product is reduced. The feeling (stickiness) tends to remain. In addition,
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.

The (a2) ethylenically unsaturated compound 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. Examples thereof include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, and 2-hydroxyethyl methacrylate. Also, (a
As the component 2), a compound having a hydroxyl group and an ethylenically unsaturated double bond obtained by ring-opening polymerization of an ε-caprolactone monomer is also exemplified. Among these compounds, 2-hydroxyethyl acrylate is preferred because the resulting cured product has no tackiness on the surface and is extremely excellent in curability. The component (a2) is used alone or in combination of two or more.

The compound (a3) of the present invention having two or more isocyanate groups in one molecule includes, for example,
Diisocyanate compounds such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, tetramethyl xylylene diisocyanate, isophorone diisocyanate, and hydrogenated products thereof. Among these compounds, isophorone diisocyanate is preferred from the viewpoint of excellent workability and low thixotropic property. The component (a3) is used alone or in combination of two or more.

The component (A) in the present invention comprises the component (a)
The mixture containing the components (1) to (a3) is prepared by adding 0.5 to 0.75 equivalents of the hydroxyl group of the component (a1) to 1 equivalent of the isocyanate group of the component (a3). Becomes 0.25 to 0.5 equivalent, (a
The sum of the hydroxyl groups of the component (1) and the component (a2) is 1 to
It is a polymer obtained by blending at a ratio of 1.1 equivalents and performing an addition reaction.

When the amount of the hydroxyl group of the component (a1) is less than 0.5 equivalent relative to 1 equivalent of the isocyanate group of the component (a3), the obtained cured product is inferior in flexibility. The surface of the obtained cured product has a tacky feeling. If the amount of the hydroxyl group of the component (a2) is less than 0.25 equivalent to 1 equivalent of the isocyanate group of the component (a3), the surface of the obtained cured product will have a tacky feeling.
If it exceeds 5 equivalents, the flexibility of the obtained cured product will be poor. Furthermore, when the total of the hydroxyl group of the component (a1) and the hydroxyl group of the component (a2) is less than 1 equivalent to 1 equivalent of the isocyanate group of the component (a3), the storage stability of the obtained photocurable resin composition is poor. When the resin composition gels and exceeds 1.1 equivalents, the curability of the resulting photocurable resin composition is poor.

Embodiment 1 of JP-A-64-24817
In the present invention, a polycarbonate polyol, 2-hydroxyethyl acrylate and isophorone diisocyanate are added as components corresponding to the components (a1), (a2) and (a3) of the present invention, respectively. Specific examples of the union and a urethane-modified acrylate compound containing the polymer are described. However, the compounding ratio of these compounds is such that the hydroxyl group of the polycarbonate polyol is 0.488 equivalent, the hydroxyl group of 2-hydroxyethyl acrylate is 1 equivalent, and the polycarbonate polyol is 1 equivalent to 1 equivalent of the isocyanate group of isophorone diisocyanate. The total number of hydroxyl groups in the hydroxyethyl acrylate is 1.
448 equivalents, the resulting urethane-modified acrylate compound has insufficient curability, and the resulting cured product has poor flexibility.

The component (A) in the present invention comprises the component (a)
The component (1), the component (a2) and the component (a3) can be obtained by blending them in the above proportions and subjecting them to an addition reaction (urethane-forming reaction). For example, the components (a1), (a2) and (a3) can be obtained. It can be obtained by mixing the components in the above ratio and heating at 70 to 80 ° C. At that time, an organic solvent can be used if necessary. As the organic solvent, for example,
Ester-based, ketone-based, aromatic-based organic solvents, and the like.Examples of the ester-based organic solvent include butyl acetate, ethyl acetate, and the like.Examples of the ketone-based organic solvent include methyl ethyl ketone and the like. 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 number average molecular weight of the component (A) is determined from the viewpoint of the properties of the obtained cured product (surface curability and flexibility of the coating film).
It is preferably from 1,000 to 7000,
More preferably 5000, 3000 to 500
More preferably, it is 0. When the number average molecular weight of the component (A) is less than 1,000, the flexibility of the resulting cured product is inferior, and the cured coating film tends to have insufficient elongation. It tends to be inferior.

The (B) ethylenically unsaturated compound having three or more ethylenically unsaturated double bonds in one molecule includes, for example, acrylate compounds and the like. Acrylate derivative, methacrylate derivative and the like. Examples of the acrylate derivative include, for example, trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, and the like. Examples of the methacrylate derivative include:
For example, trimethylolpropane trimethacrylate,
Pentaerythritol trimethacrylate, tris (2
-Hydroxyethyl) isocyanurate trimethacrylate and the like. Among these monomers,
Tris (2-hydroxyethyl) isocyanurate triacrylate is preferred from the viewpoint of the surface curability of the obtained coating film. These monomers are used alone or in combination of two or more.

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, and a peroxide-based photopolymerization initiator.

Examples of the carbonyl-based photopolymerization initiator include benzophenone, 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, benzyl methyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-
Methyl-1-phenyl-propan-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 and di-t-butyl peroxide. Among these photopolymerization initiators, 2-hydroxy-2-methyl-1-phenyl-propan-1-one is preferable from the viewpoint of solubility in the obtained photocurable resin composition. These photopolymerization initiators are used alone or in combination of two or more.

The mixing ratio of the component (A) is determined based on the balance of the properties (curability, flexibility (elongation) and adhesion) of the obtained cured product (coating film). Preferably, the content is 50 to 90% by weight based on the total amount of the components.
The content is more preferably 50 to 80% by weight, and 50 to 7% by weight.
More preferably, it is 0% by weight. If the compounding ratio is less than 50% by weight, the flexibility and adhesiveness of the obtained cured product tend to sharply decrease, and if it exceeds 90% by weight, the curability of the obtained cured product is inferior and the cured product becomes inferior. Tackiness tends to remain on the surface.

The mixing ratio of the component (B) is determined based on the balance of the properties (curability, flexibility (elongation), adhesion, etc.) of the obtained cured product (coating film). It is preferred to be 10 to 50% by weight based on the total amount of the components,
It is more preferably 20 to 50% by weight, and 30 to 5% by weight.
More preferably, it is 0% by weight. If the compounding ratio is less than 10% by weight, the curability of the obtained cured product is inferior and the tackiness tends to remain on the surface of the cured product. The tendency tends to decrease rapidly.

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

The photocurable resin composition of the present invention comprises (D) one or two ethylenically unsaturated double bonds in one molecule as a diluent in addition to the components (A) to (C). It may contain an ethylenically unsaturated compound. Examples of the component (D) include acrylic ester derivatives, methacrylic ester derivatives, diacryloxyethyl phosphate, dimethacryloxyethyl phosphate, N-vinylpyrrolidone, and the like. For example, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate and the like, and as the methacrylate derivative, for example, Tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl gly Over dimethacrylate and the like, acrylic acid ester derivatives.

The mixing ratio of the component (D) is not particularly limited as long as the properties (curability, flexibility (elongation), adhesion, etc.) of the obtained cured product are not impaired.
The content is preferably not more than 50% by weight based on the total amount of the components (A), (B) and (C).

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, filler, extender, pigment, polymerization inhibitor, leveling agent, modifier, plasticizer, 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 the like, and examples of the synthetic polymer include unsaturated polyester resins, Vinyl ester resin, vinyl urethane resin, vinyl ester urethane resin, polyisocyanate, polyepoxide, acrylic resin, alkyd resin, urea resin, melamine resin, polydiene elastomer, saturated polyester, saturated polyether, cellulose derivative, Epoxidized oils and the like can be mentioned.
Examples of the cellulose derivative include nitrocellulose, cellulose acetate butyrate, and the like.

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. As the polymerization inhibitor, for example, hydroquinone, hydroquinone monomethyl ether, benzoquinone, p-
tert-butylcatechol, 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 substance, filler, extender pigment, pigment, polymerization inhibitor, leveling agent, modifier and plasticizer is appropriately selected depending on the use of the obtained paint, and is particularly limited. Although not essential, the total amount of these components is preferably 70% by weight or less based on the weight of the coating material. The mixing ratio of the organic solvent is appropriately selected depending on the use of the obtained coating material, and is not particularly limited, but is preferably 50% by weight or less based on the weight of the coating material.

As a method of forming a coating, for example, 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 machine, an airless spray machine, 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 and is made of a metal material such as iron and aluminum, a calcium silicate plate, a pulp cement plate, a lightweight concrete plate, an asbestos cement plate, an inorganic building material such as mortar, wood, paper, and a plastic base. It can be used for coating materials and the like, and after coating, the coating film can be cured by irradiating the coating film with ultraviolet rays using a high-pressure mercury lamp, a metal halide lamp or the like as a light source.

[0029]

The present invention will be described below with reference to examples. In addition, part and% show a weight part and weight%, respectively.

Production Example 1 Production of Polymer Solution (A-1) 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 (Hydroxyl group: 2.0
Equivalents), 1,9-nonanediol and 2-methyl-1,8
A polycarbonate diol comprising octanediol and diphenyl carbonate (trade name: P, manufactured by Kuraray Co., Ltd.)
NOC-2000, number average molecular weight: about 2000) 409
4 parts (hydroxyl group: 2.0 equivalents), 2.5 parts hydroquinone monomethyl ether (manufactured by Wako Pure Chemical Industries, Ltd.),
Dibutyltin dilaurate (Tokyo Fine Chemical Co., Ltd.)
, Trade name: L101) 4.99 parts and methyl ethyl ketone 1050 parts were charged, and heated to 70 ° C.,
The mixture was kept warm at 5 ° C. for 30 minutes, and added thereto with isophorone diisocyanate (trade name: VEST, manufactured by Daicel Huls).
666 parts of ANAT IPDI (isocyanate group:
(3.0 equivalents) and a mixed liquid of 1108 parts of methyl ethyl ketone were uniformly added dropwise over 3 hours to react. After completion of the dropwise addition, the reaction was carried out by keeping the temperature at 70 to 75 ° C. for about 5 hours, and after confirming that the isocyanate had disappeared by IR measurement,
The reaction was terminated to obtain a polymer solution (A-1). The resin solid content of the obtained polymer solution (A-1) was about 70%, and the number average molecular weight of the polymer was 4,800.

Production Example 2 Production of Polymer Solution (A-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 (Hydroxyl group: 2.0
Equivalent), a polycarbonate diol comprising linear hexanediol, 3-methylpentanediol and diphenyl carbonate (trade name: CD, manufactured by Daicel Chemical Industries, Ltd.)
220PL, number average molecular weight: about 2000) 4106 parts (hydroxyl group: 2.0 equivalent), hydroquinone monomethyl ether (manufactured by Wako Pure Chemical Industries, Ltd.) 2.5 parts, dibutyltin dilaurate (manufactured by Tokyo Fine Chemical Co., Ltd.) Trade name: L101) 5 parts and methyl ethyl ketone 1050
After heating to 70 ° C., the mixture was kept at 70 to 75 ° C. for 30 minutes, and then added with isophorone diisocyanate (trade name: VESTANAT IP manufactured by Daicel Huls Co., Ltd.).
A mixed liquid of 666 parts (DI) (isocyanate group: 3.0 equivalents) and 1113 parts of methyl ethyl ketone was uniformly dropped over 3 hours to react. After the completion of the dropwise addition, the reaction was carried out while keeping the temperature at 70 to 75 ° C. for about 5 hours. After confirming that the isocyanate had disappeared by IR measurement, the reaction was terminated to obtain a polymer solution (A-2). The obtained polymer solution (A-
The resin solid content in 2) was about 70%, and the number average molecular weight of the polymer was 5,000.

Production Example 3 Production of Polymer Solution (A-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 (Hydroxyl group: 2.0
Equivalent), polycarbonate diol comprising 1,6-hexanediol, 1,5-pentanediol and diphenyl carbonate (Enichem Synth
4039 parts (hydroxyl group: product name: RAVECARB107, number average molecular weight: about 2,000) manufactured by E.S.
2.0 equivalents), 2.47 parts of hydroquinone monomethyl ether (manufactured by Wako Pure Chemical Industries, Ltd.), dibutyltin dilaurate (manufactured by Tokyo Fine Chemical Co., Ltd., trade name: L101)
4.94 parts and 1050 parts of methyl ethyl ketone were charged, and after the temperature was raised to 70 ° C, the temperature was kept at 70 to 75 ° C for 30 minutes,
To this, isophorone diisocyanate (trade name: VESTANAT IPDI, manufactured by Daicel Huls) 6
A mixed liquid of 66 parts (isocyanate group: 3.0 equivalents) and 1084 parts of methyl ethyl ketone was uniformly dropped over 3 hours to react. After completion of the dropwise addition, the reaction was carried out while keeping the temperature at 70 to 75 ° C. for about 5 hours. After confirming that the isocyanate had disappeared by IR measurement, the reaction was terminated to obtain a polymer solution (A-3). The resin solid content of the obtained polymer solution (A-3) is about 70%, and the number average molecular weight of the polymer is 4%.
800.

Examples 1 to 4 and Comparative Example 1 The polymer solutions (A-1) to (A-
Using 3), the components shown in Table 1 were blended and uniformly mixed to obtain photocurable resin compositions (R-1) to (R-4) and (CR-1). Using an applicator, the film thickness is 1
The photocurable resin composition obtained so as to have a thickness of 50 μm is applied on a glass plate, dried in a hot air drier heated to 60 ° C. for about 10 minutes, and after the organic solvent is volatilized, an ultraviolet irradiation device ( Nippon Battery Co., Ltd., output: 6kw, number of high-pressure mercury lamps:
80 w / cm x 2 lamps), turning on only one high pressure mercury lamp 80 w / cm, irradiation distance 15 cm, conveyor speed 5 m / min,
Irradiation was performed once under the condition of one irradiation amount of about 500 mJ / cm ² to obtain an evaluation test film (cured film) having a film thickness of about 50 μm.

[0034]

[Table 1]

The obtained photocurable resin composition and evaluation test film were evaluated as follows (low-temperature stability test, curability test, pencil hardness test, elongation and tensile strength of evaluation test film), and the results. Are shown in Table 2.

(1) Low Temperature Stability Test The obtained photocurable resin composition was allowed to stand at 0 ° C. for 1 week, and the state of the photocurable resin composition was visually observed and evaluated according to the following criteria. ：: no change ×: cloudiness or crystallization (2) Curability test The surface of the evaluation test film was touched with a finger, and the tackiness (stickiness) of the surface was evaluated according to the following criteria. ○: No tackiness ×: Tackiness

(3) Pencil hardness test According to JIS K5400, a pencil scratch test was performed.
The evaluation was based on the hardness of the pencil used. (4) Elongation and tensile strength of the evaluation test film The evaluation test film was cut out into a strip having a length of 100 mm and a width of 10 mm, adjusted to a test span of 50 mm, and adjusted to room temperature (23 ±
At 3 ° C) and at a low temperature (-20 ± 3 ° C), the film was stretched at a tensile speed of 50 mm / min until the test film broke, and the elongation (mm) and strength (kgf) of the film at break were measured. The elongation and tensile strength of the evaluation test film were determined from the following formulas.

[0038]

(Equation 1) (Where S indicates the test span (mm))

(Equation 2) (Where A represents the width (mm) of the evaluation test film and B represents its thickness (mm))

[0039]

[Table 2]

According to Table 2, in the photocurable resin composition obtained in Comparative Example 1, the evaluation result in the column of curability was "x" (tackiness), and the pencil hardness was The evaluation result in the column was “less than 6B”, and the evaluation result in the tensile strength at room temperature column was “50 kgf / cm ² ”. The hardness and tensile strength at room temperature were very poor. Further, Comparative Examples 3 and 4
In each of the photocurable resin compositions obtained in the above, the evaluation result in the column of pencil hardness was “4B”, and the evaluation result in the column of elongation at low temperature was “5%”. These photocurable resin compositions had extremely poor elongation at low temperatures and poor pencil hardness.

On the other hand, according to Table 2, the evaluation results in the low-temperature stability column of the photocurable resin compositions obtained in Examples 1 and 2 are “O” (no change). The evaluation result in the column of the curability test is “試 験” (no tackiness), the evaluation result in the column of pencil hardness is “B” or “H”, and the evaluation result in the column of the elongation percentage of the evaluation test film is The evaluation results were "30" or more at room temperature and "25" or more at low temperature, and the evaluation results in the column of tensile strength were "215" or more at room temperature and "400" or more at low temperature. The photocurable resin composition was excellent in low-temperature stability, curability and tensile strength, and extremely excellent in pencil hardness and elongation.

In the photocurable resin compositions obtained in Examples 3 and 4, the evaluation result in the column of low-temperature stability was “○” (no change), and the evaluation in the column of the curability test was performed. The result was “○” (no tackiness), the evaluation result in the column of elongation percentage of the evaluation test film was “10” or more at room temperature, “5” at low temperature, and The evaluation results were "285" at room temperature and "635" or more at low temperature, and these photocurable resin compositions were excellent in low-temperature stability, curability, elongation, and tensile strength.

[0043]

The photocurable resin composition according to claim 1 is
It has excellent curability and is suitable for paints. The photocurable resin composition according to claim 2 has the effects of the invention according to claim 1,
Further, the obtained cured product has excellent flexibility and is suitable for paint. The photocurable resin composition according to the third aspect is the first aspect.
Or the effect of the invention described in 2 is obtained, and further, it has low viscosity and excellent workability, and is suitable for a paint. The paint according to claim 4 is excellent in curability.

Claims (4)

[Claims] (A1) a (a1) polycarbonate diol compound, (a2) an ethylenically unsaturated compound having a hydroxyl group and (a3) a compound having two or more isocyanate groups in one molecule, With respect to one equivalent of the isocyanate group, the hydroxyl group of the component (a1) becomes 0.5 to 0.75 equivalent, the hydroxyl group of the component (a2) becomes 0.25 to 0.5 equivalent, and the components (a1) and ( a2) a polymer obtained by blending the components in a proportion such that the total of the hydroxyl groups of the component is 1 to 1.1 equivalents and subjecting to an addition reaction, (B) a polymer having three or more ethylenically unsaturated double bonds in one molecule A photocurable resin composition comprising an ethylenically unsaturated compound and (C) a photopolymerization initiator. 2. The method of claim 1, wherein (a1) the polycarbonate diol compound is 1,9-nonanediol, 2-methyl-1,8-
The photocurable resin composition according to claim 1, which is a compound obtained by reacting octanediol and diphenyl carbonate. 3. The photocurable resin composition according to claim 1, wherein (a3) the compound having two or more isocyanate groups in one molecule is isophorone diisocyanate. 4. A coating comprising the photocurable resin composition according to claim 1.