JP2006089627A - Photo-curing resin composition and coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photo-curing resin composition and a coating, which has viscosity sufficiently good for working property and good property of curing coating film surfaces, so as to be able to form a cured coating film having sufficiently high mechanical strength, sufficiently high elongation, and sufficiently good adhesiveness with a substrate. <P>SOLUTION: The photo-curing resin composition contains (A) a urethan compound, (B) a photopolymerizable monomer having a reactive unsaturated group, and (C) a photopolymerization initiator, wherein the urethan compound is obtained by mixing (a) an isocyanate compound having two isocyanate groups in one molecule, (b) a polyoxyalkylene glycol having a number average molecular weight of greater than 1,000 and 2,500 or less, (c) an alkylene glycol or a polyoxyalkylene glycol having a number average molecular weight of 62 or more and 1,000 or less, and (d) an ethylenic unsaturated compound having a hydroxyl group to cause reaction, so that the ratio of the number of moles of component (b) to that of component (c) is 1 or more, and the equivalent ratios of the hydroxyl groups of component (b), component (c), and component (d) to the isocyanate group of component (a) range from 1.0 to 1.1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

  In recent years, photocurable resin compositions that can be cured by irradiation with ultraviolet rays or electron beams have been developed and used for coatings for coatings, adhesives, pressure-sensitive adhesives, and the like. Since the photocurable resin composition can be efficiently cured as compared with the thermosetting resin composition, recently, the use of coating is increasing for the purpose of improving productivity.

  In this coating application, in general, not only the curability of the coating film surface but also the physical properties and appearance of the formed cured coating film are required for the photocurable resin composition. Furthermore, from the viewpoint of workability such as ease of handling and ease of coating, a lower viscosity photocurable resin composition is required. In the field of woodwork painting, wood-based plywood made of cheap imported timber is increasing, and the material of the painted area is diverse. For this reason, the photocurable resin composition is also required to have excellent adhesion to a coating site (base material). In other words, there is a need for a photocurable resin composition that is excellent in workability, has sufficient curability and coating strength, which are necessary properties for coating applications, and has a sufficient elongation of the cured coating. It has been.

  By the way, recently, since it is easy to adjust the physical properties and the like of the coating film, various photocurable resin compositions using urethane-modified acrylate have been developed (for example, see Patent Documents 1 to 4).

Japanese Patent Application Laid-Open No. 50-66596 JP 50-94090 A JP-A-48-25095 JP-A 64-24817

  However, in the conventional photocurable resin compositions including those described in Patent Documents 1 to 4, if the viscosity of the photocurable resin composition is set low in consideration of workability, the elongation of the cured coating film is increased. The rate is lowered, and the adhesion with the coating site (base material) becomes insufficient. On the other hand, when the molecular weight of the resin is increased for the purpose of improving the elongation rate of the cured coating film, the viscosity of the photocurable resin composition is increased, the workability is decreased, and the surface curability of the coating film is also decreased. . Therefore, in order to satisfy the above-mentioned characteristics at the same time, further improvements are required in the conventional photocurable resin composition.

  The present invention has been made in view of the above circumstances, has a viscosity that is sufficiently excellent in workability, is excellent in curability of the coating film surface, and can form a cured coating film having sufficiently high mechanical strength, It aims at providing the photocurable resin composition and coating material which can form the cured coating film which has a sufficiently high elongation rate, and was sufficiently excellent in adhesiveness with a base material.

  As a result of intensive studies to achieve the above object, the present inventors are excellent in workability and curability by using a urethane compound obtained by mixing and reacting a specific compound at a specific ratio, and It was found that a cured coating film satisfying the above-mentioned characteristics can be obtained. That is, a photocurable resin composition containing a urethane compound obtained by mixing and reacting a specific compound at a specific ratio, a photopolymerizable monomer, and a photopolymerization initiator does not use a solvent. Has a sufficiently low viscosity, is excellent in the curability of the coating film surface, and further, has found that the formed cured coating film has a sufficiently high mechanical strength and a sufficiently high elongation rate. Completed.

  The photocurable resin composition of the present invention contains (A) a urethane compound, (B) a photopolymerizable monomer having a reactive unsaturated group, and (C) a photopolymerization initiator. (A) an isocyanate compound having two isocyanate groups in one molecule, (b) a polyoxyalkylene glycol having a number average molecular weight of more than 1000 and not more than 2500, and (c) a number average molecular weight of 62 to 1000. The ratio of the number of moles of the component (b) to the number of moles of the component (c) of the alkylene glycol or polyoxyalkylene glycol and (d) the hydroxyl group-containing ethylenically unsaturated compound is 1 or more, and the component (a) Obtained by mixing and reacting so that the equivalent ratio of the hydroxyl groups of the component (b), component (c) and component (d) to the isocyanate group is 1.0 to 1.1. A.

  In the present invention, the “number average molecular weight” is a value measured by gel permeation chromatography and determined using a standard polystyrene calibration curve.

  The photocurable resin composition of the present invention contains the above urethane compound, and further contains the above (B) component and (C) component, thereby having a viscosity sufficiently excellent in workability, and a coating film surface. It is possible to form a cured coating film that is excellent in curability and has a sufficiently high mechanical strength, and can form a cured coating film that has a sufficiently high elongation rate and sufficiently excellent adhesion to a substrate. Yes. Moreover, since the photocurable resin composition of the present invention has a viscosity that is sufficiently excellent in workability even when no solvent is used, it can be used as a solventless paint.

  When the ratio of the number of moles of the component (b) to the number of moles of the component (c) is less than 1, that is, the polyoxyalkylene glycol having a number average molecular weight of 62 or more and 1000 or less has a number average molecular weight of more than 1000 and 2500. When the amount is larger than the following alkylene glycol or polyoxyalkylene glycol, the photocurable resin composition containing the urethane compound obtained in this case has too high a viscosity and the workability is lowered. Moreover, the cured coating film to be formed has poor flexibility and becomes brittle, and the adhesion to the substrate becomes insufficient.

  In addition, when the equivalent ratio of the hydroxyl groups of the component (b), the component (c), and the component (d) to the isocyanate group of the component (a) is less than 1, the photocurable resin composition gels during storage. Problems arise in practice. On the other hand, when the equivalent ratio exceeds 1.1, the formed cured coating film cannot have a sufficiently high elongation and a sufficiently high mechanical strength.

式（１）中、ｘ、ｙ及びｚは正の整数であり、下記式（Ｉ）及び（ＩＩ）；
０．１≦［（ｘ＋ｚ）／ｙ］≦１．０ …（Ｉ）
１５≦（ｘ＋ｙ＋ｚ）≦４０ …（ＩＩ）
を満たす。 Moreover, in the photocurable resin composition of this invention, it is preferable that said (b) component contains polyoxyalkylene glycol represented by following General formula (1).

In the formula (1), x, y and z are positive integers, and the following formulas (I) and (II):
0.1 ≦ [(x + z) / y] ≦ 1.0 (I)
15 ≦ (x + y + z) ≦ 40 (II)
Meet.

  As a polyoxyalkylene glycol having a number average molecular weight of more than 1000 and not more than 2500, a urethane compound obtained by using the above-described copolymer-based polyether polyol compound has a low intermolecular interaction, so that it is a photocurable resin composition. The viscosity of the product can be reduced more reliably, the molecular weight of the urethane compound obtained is not much different from the conventional one, sufficiently excellent in the curability of the coating surface and adhesion to the substrate, and at a higher level the elongation rate A cured coating film satisfying the strength can be formed more reliably.

  In the polyoxyalkylene glycol represented by the general formula (1), when (x + y + z), that is, the total of the average added moles of ethylene oxide and propylene oxide is less than 15, a cured coating film formed (particularly, , The flexibility (elongation rate) of the cured film formed in a film shape tends to be insufficient. On the other hand, when (x + y + z) exceeds 40, the curing rate of the photocurable resin composition tends to be slow. Therefore, sufficient curability of the coating film surface and sufficient coating strength tend to be difficult to obtain.

  In addition, in the polyoxyalkylene glycol represented by the general formula (1), [(x + z) / y], that is, the total (x + z) of the average added mole number of ethylene oxide with respect to the average added mole number y of propylene oxide. When the ratio is less than 0.1, the curing rate of the photocurable resin composition tends to be slow. On the other hand, when [(x + z) / y] exceeds 1.0, the photocurable resin composition The viscosity tends to increase, workability tends to decrease, and the hardness and strength of the formed cured coating film tend to be insufficient.

式（２）中、Ｒ^１は、水素又はメチル基を示し、ｎは、正の整数である。 Furthermore, in the photocurable resin composition of the present invention, the component (b) preferably further contains a polyoxyalkylene glycol represented by the following general formula (2).

In formula (2), R ¹ represents hydrogen or a methyl group, and n is a positive integer.

  When the component (b) further contains such a polyoxyalkylene glycol, the viscosity of the resulting photocurable resin composition can be more reliably reduced, and the curability of the coating film surface and the adhesion to the base material can be reduced. It is possible to form a cured coating film that is sufficiently excellent and satisfies the elongation and strength at a higher level more reliably. In addition, by using the polyoxyalkylene glycol represented by the general formula (2), the viscosity of the photocurable resin composition can be further reduced even when the molecular weight of the urethane compound is increased. The photocurable resin composition having a good elongation can be obtained more reliably.

式（３）中、ｐ、ｑ及びｒは、正の整数である。

式（４）中、Ｒ^２は、水素又はメチル基を示し、ｍは、正の整数である。 In the photocurable resin composition of the present invention, the component (c) includes a polyoxyalkylene glycol represented by the following general formula (3) and / or an alkylene glycol represented by the following general formula (4). Or it is preferable to contain polyoxyalkylene glycol.

In formula (3), p, q, and r are positive integers.

In Formula (4), R ² represents hydrogen or a methyl group, and m is a positive integer.

  When component (c) contains alkylene glycol or polyoxyalkylene glycol as described above, the viscosity of the resulting photocurable resin composition can be more reliably reduced, and the curability of the coating film surface and the substrate can be reduced. It is possible to more reliably form a cured coating film that is sufficiently excellent in adhesiveness and that satisfies elongation and strength at a higher level.

Furthermore, in the photocurable resin composition of the present invention, the ratio M _OH / M _a between the number of moles M _{OH of the} hydroxyl group of the component (d) and the number of moles M _a of the isocyanate compound of the component (a) is 3 / 5 to 1 is preferable.

When the above (M _OH / M _a ) is less than 3/5, that is, when the total number of moles of hydroxyl groups of the component (d) is 3, and the number of moles of the isocyanate compound exceeds 5, photocuring The curability of the curable resin composition tends to be insufficient, and the strength of the formed cured coating film tends to be insufficient. Furthermore, the viscosity of the photocurable resin composition increases and the workability tends to decrease. On the other hand, when (M _OH / M _a ) exceeds 1, that is, when the total number of moles of hydroxyl groups of component (d) is 3, and the number of moles of isocyanate compound is less than 3, the cured coating formed The film elongation tends to be insufficient.

  Further, in the photocurable resin composition of the present invention, the number average molecular weight of the urethane compound is 1000 to 4000, and the ratio of the weight average molecular weight of the urethane compound to the number average molecular weight is 3.0 or less. Preferably there is.

  In the present invention, the “weight average molecular weight” is a value measured by gel permeation chromatography and determined using a standard polystyrene calibration curve.

  If the number average molecular weight of the urethane compound is less than 1000, the cured coating film tends to be brittle, and if it exceeds 4000, the curability of the photocurable resin composition tends to decrease. The hardness of the steel tends to be insufficient, and the crack resistance tends to decrease. On the other hand, when the ratio of the weight average molecular weight to the number average molecular weight exceeds 3.0, the hardness of the cured coating film tends to be insufficient and the crack resistance tends to decrease.

Further, in the photocurable resin composition of the present invention, (A) the ratio _M A / _{M B} between the mass _{M A} component (B) component of the mass _{M B} is a 95 / 5-40 / 60, And it is preferable that the content rate of (C) component is 1-10 mass parts with respect to a total of 100 mass parts of (A) component and (B) component.

The above M _{A /} M _B is more than 95/5, the working viscosity of the photocurable resin composition becomes higher tends to decrease. On the other hand, the M A _/ M _B, is less than 40/60, curability of the photocurable resin composition, and tends to elongation and strength of the cured coating film becomes insufficient.

  Further, if the content ratio of the component (C) is less than 1 part by mass, the photocurability tends to be insufficient, and if it exceeds 10 parts by mass, the characteristics (hardness) of the formed cured coating film , Strength, flexibility (elongation rate, etc.) tend to decrease.

  Moreover, the photocurable resin composition of this invention contains 70 mass parts of urethane compounds which are (A) components, and 30 mass parts of acryloyl morpholine as (B) components, and the viscosity in 25 degreeC is 1500-500. It is preferably 3500 mPa · s.

  Such a photocurable resin composition has better workability even when no solvent is used, sufficiently excellent in the curability of the coating film surface and the adhesion to the substrate, and higher. A cured coating film that satisfies the elongation and strength at a level can be more reliably formed.

  Moreover, the coating material of this invention contains either of the above-mentioned photocurable resin compositions of this invention.

  The paint of the present invention has a viscosity that is sufficiently excellent in workability by using the photocurable resin composition of the present invention, is excellent in curability of the coating surface, and has a sufficiently high mechanical strength. In addition, a cured coating film having a sufficiently high elongation and sufficiently excellent adhesion to the substrate can be formed. Moreover, the coating material of the present invention can have a viscosity that is sufficiently excellent in workability even when a solvent is not used by using the photocurable resin composition of the present invention, and is used as a useless type coating material. be able to.

  According to the present invention, it is possible to form a cured coating film having a viscosity that is sufficiently excellent in workability, excellent in curability of the coating film surface, and having sufficiently high mechanical strength, and has a sufficiently high elongation rate. The photocurable resin composition and coating material which can form the cured coating film sufficiently excellent in adhesiveness with a material can be provided.

  Hereinafter, embodiments of the present invention will be described in detail.

  In the present embodiment, (meth) acrylate means acrylate or a corresponding methacrylate. The “number average molecular weight” is measured by gel permeation chromatography, and the value obtained using a standard polystyrene calibration curve is used. The “weight average molecular weight” is measured by gel permeation chromatography, and the standard polystyrene calibration curve is The value obtained by using is used.

  The photocurable resin composition of this embodiment contains (A) a urethane compound, (B) a photopolymerizable monomer having a reactive unsaturated group, and (C) a photopolymerization initiator. (A) an isocyanate compound having two isocyanate groups in one molecule, (b) a polyoxyalkylene glycol having a number average molecular weight of more than 1000 and not more than 2500, and (c) a number average molecular weight of 62 to 1,000. The ratio of the number of moles of component (b) to the number of moles of component (c) is 1 or more, and (a) an alkylene glycol or polyoxyalkylene glycol and (d) an ethylenically unsaturated compound having a hydroxyl group It is obtained by mixing and reacting so that the equivalent ratio of the hydroxyl groups of component (b), component (c) and component (d) to the isocyanate group of the component is 1.0 to 1.1. It is necessary that the the is.

  (A) As an isocyanate compound having two isocyanate groups in one molecule, for example, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate, Examples thereof include norbornene diisocyanate and diisocyanate compounds such as hydrogenated products thereof.

  Furthermore, a burette type polyisocyanate compound obtained by reacting the above various diisocyanate compounds with water, an adduct type polyisocyanate compound obtained by reacting the above various diisocyanate compounds with a polyhydric alcohol such as trimethylolpropane, Multimers obtained by converting the above various diisocyanate compounds to isocyanurates can be used.

  Said isocyanate compound can be used individually by 1 type or in combination of 2 or more types.

で表される共重合系ポリエーテルポリオールが挙げられる。なお、上記式（１）中、ｘ及びｙはエチレンオキサイドの平均付加モル数を示す正の整数であり、ｙはプロピレンオキサイドの平均付加モル数を示す正の整数であり、エチレンオキサイド及びプロピレンオキサイドはブロック結合している。 (B) As a polyoxyalkylene glycol having a number average molecular weight of more than 1000 and 2500 or less, for example, the following general formula (1);

The copolymer type polyether polyol represented by these is mentioned. In the above formula (1), x and y are positive integers indicating the average number of added moles of ethylene oxide, y is a positive integer indicating the average number of added moles of propylene oxide, and ethylene oxide and propylene oxide. Are block connected.

In the present embodiment, in the above formula (1), x, y and z are the following formulas (I) and (II);
0.1 ≦ [(x + z) / y] ≦ 1.0 (I)
15 ≦ (x + y + z) ≦ 40 (II)
It is preferable to satisfy.

  In the polyoxyalkylene glycol represented by the general formula (1), when (x + y + z), that is, the total of the average added moles of ethylene oxide and propylene oxide is less than 15, a cured coating film formed (particularly, , The flexibility (elongation rate) of the cured film formed in a film shape tends to be insufficient. On the other hand, when (x + y + z) exceeds 40, the curing rate of the photocurable resin composition tends to be slow. Therefore, sufficient curability of the coating film surface and sufficient coating strength tend to be difficult to obtain.

  In addition, in the polyoxyalkylene glycol represented by the general formula (1), [(x + z) / y], that is, the total (x + z) of the average added mole number of ethylene oxide with respect to the average added mole number y of propylene oxide. When the ratio is less than 0.1, the curing rate of the photocurable resin composition tends to be slow. On the other hand, when [(x + z) / y] exceeds 1.0, the photocurable resin composition The viscosity tends to increase, workability tends to decrease, and the hardness and strength of the formed cured coating film tend to be insufficient.

で表されるポリオキシアルキレングリコールが挙げられる。なお、式（２）中、Ｒ^１は、水素又はメチル基を示し、ｎは、正の整数である。 Moreover, as (b) polyoxyalkylene glycol whose number average molecular weight is more than 1000 and 2500 or less, the following general formula (2);

The polyoxyalkylene glycol represented by these is mentioned. In formula (2), R ¹ represents hydrogen or a methyl group, and n is a positive integer.

  In this embodiment, it is preferable that (b) component contains the polyoxyalkylene glycol represented by the said General formula (1), and the polyoxyalkylene glycol represented by the said General formula (2). By using together the polyoxyalkylene glycol represented by the general formula (1) and the general formula (2), it is easier to balance the viscosity of the photocurable resin composition and the physical properties of the coating film. Can be.

  (C) As the alkylene glycol having a number average molecular weight of 62 or more and 1000 or less, monoethylene glycol, diethylene glycol, monopropylene glycol, dipropylene glycol, monobutylene glycol, dibutylene glycol, monopentylene glycol, dipentylene glycol, Examples include monohexylene glycol and dihexylene glycol.

で表される共重合系ポリエーテルポリオールが挙げられる。なお、式（３）中、ｐ及びｒはエチレンオキサイドの平均付加モル数を示す正の整数であり、ｑはプロピレンオキサイドの平均付加モル数を示す正の整数であり、エチレンオキサイド及びプロピレンオキサイドはブロック結合している。 Moreover, as (c) polyoxyalkylene glycol whose number average molecular weight is 62 or more and 1000 or less, the following general formula (3);

The copolymer type polyether polyol represented by these is mentioned. In formula (3), p and r are positive integers indicating the average added mole number of ethylene oxide, q is a positive integer indicating the average added mole number of propylene oxide, and ethylene oxide and propylene oxide are The blocks are connected.

で表されるポリオキシアルキレングリコールが挙げられる。なお、式（４）中、Ｒ^２は、水素又はメチル基を示し、ｍは、−ＣＨＲ^２ＣＨ_２Ｏ−の平均付加モル数を示す正の整数である。 Furthermore, the following general formula (4) such as polyethylene glycol such as triethylene glycol and polypropylene glycol such as tripropylene glycol;

The polyoxyalkylene glycol represented by these is mentioned. In the formula (4), R ² represents hydrogen or a methyl group, and m is a positive integer indicating the average added mole number of —CHR ² CH ₂ O—.

  In addition, polybutylene glycol such as tributylene glycol, polypentylene glycol such as tripentylene glycol, polyhexylene glycol such as trihexylene glycol, and the like can be given.

  In this embodiment, it is preferable to use polyethylene glycol or polypropylene glycol having a number average molecular weight of 200 to 1,000. In particular, by using diethylene glycol or polyethylene glycol, the toughness of the coating film can be further improved, and by using propylene glycol having a side chain, the viscosity of the photocurable resin composition is more reliably reduced. You can plan. Moreover, said (c) alkylene glycol and polyoxyalkylene glycol whose number average molecular weight is 62 or more and 1000 or less can be used individually by 1 type or in combination of 2 or more types.

  (D) Examples of the ethylenically unsaturated compound having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth). Examples thereof include hydroxyalkyl (meth) acrylates having 2 to 7 carbon atoms in the alkyl group such as acrylate. Furthermore, it is obtained by ring-opening polymerization of (meth) acrylate compounds such as polyethylene glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate; N-methylolacrylamide, N-methylolmethacrylamide, and ε-caprolactone monomer. Examples include compounds having a hydroxyl group and an ethylenically unsaturated double bond. These can be used alone or in combination of two or more.

  Moreover, in the photopolymerizable resin composition of this embodiment, 2-hydroxyethyl acrylate is used among the above compounds from the viewpoint of excellent curability of the coating film surface and curability of the formed cured coating film. preferable.

  (A) The urethane compound is obtained by mixing the components (a), (b), (c), and (d), and reacting them at 60 to 80 ° C. for 5 to 12 hours. be able to. In that case, reaction catalysts, 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, examples of the ketone organic solvent include methyl ethyl ketone, and examples of the aromatic organic solvent include toluene and xylene. It is done. These organic solvents can be used individually by 1 type or in combination of 2 or more types.

  In this embodiment, when (A) urethane compound is obtained by mixing and reacting the components (a), (b), (c), and (d), the number of moles of component (c) The ratio of the number of moles of the component (b) to 1 or more, and the equivalent ratio of the hydroxyl groups of the component (b), the component (c) and the component (d) to the isocyanate group of the component (a) is 1.0 to 1. It is necessary to mix so that it becomes 1.

  When the ratio of the number of moles of the component (b) to the number of moles of the component (c) is less than 1, that is, the polyoxyalkylene glycol having a number average molecular weight of 62 or more and 1000 or less has a number average molecular weight of more than 1000 and 2500. When the amount is larger than the following alkylene glycol or polyoxyalkylene glycol, the photocurable resin composition containing the urethane compound obtained in this case has too high a viscosity and the workability is lowered. Moreover, the cured coating film to be formed has poor flexibility and becomes brittle, and the adhesion to the substrate becomes insufficient.

  In addition, when the equivalent ratio of the hydroxyl groups of the component (b), the component (c), and the component (d) to the isocyanate group of the component (a) is less than 1, the photocurable resin composition gels during storage. Problems arise in practice. On the other hand, when the equivalent ratio exceeds 1.1, the formed cured coating film cannot have a sufficiently high elongation and a sufficiently high strength.

Further, when (A) the urethane compound is obtained, the ratio M _OH / M _a between the number of moles M _{OH of the} hydroxyl group of the component (d) and the number of moles M _a of the isocyanate compound of the component (a) is 3/5. It is preferable to mix so that it may become ~ 1.

When the above M _OH / M _a is less than 3/5, that is, when the number of moles of the hydroxyl group of the component (d) is 3, and the number of moles of the isocyanate compound exceeds 5, the photocurable resin composition The curability of the product tends to be insufficient, and the strength of the formed cured coating film tends to be insufficient. Furthermore, the viscosity of the photocurable resin composition increases and the workability tends to decrease. On the other hand, if M _OH / M _a exceeds 1, that is, if the number of moles of isocyanate compound is less than 3 when the number of moles of hydroxyl group OH of component (d) is 3, the cured coating film formed Elongation rate tends to be insufficient.

  In the photocurable resin composition of the present embodiment, the number average molecular weight of the urethane compound is 1000 to 4000, and the ratio of the weight average molecular weight of the urethane compound to the number average molecular weight (Mw / Mn). Is preferably 3.0 or less.

  If the number average molecular weight of the urethane compound is less than 1000, the cured coating film tends to be brittle, and if it exceeds 4000, the curability of the photocurable resin composition tends to decrease. The hardness of the steel tends to be insufficient, and the crack resistance tends to decrease.

  Moreover, when said (Mw / Mn) exceeds 3.0, the hardness of a cured coating film becomes inadequate and there exists a tendency for crack resistance to fall.

  (B) As a photopolymerizable monomer having a reactive unsaturated group, a monofunctional or polyfunctional photopolymerizable monomer having a reactive unsaturated group such as a vinyl group, an acryloyl group, or a methacryloyl group The body is mentioned. For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) Alkyl (meth) acrylates such as acrylate, isodecyl (meth) acrylate, n-hexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate; ethoxyethyl (meth) acrylate, methoxyethyl Alkoxyalkyl (meth) acrylates such as (meth) acrylate, butoxyethyl (meth) acrylate, 2-methoxyethoxyethyl (meth) acrylate and 2-ethoxyethoxyethyl (meth) acrylate Relate; hydroxyalkyl (meth) acrylates such as glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate; methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydi Alkoxy (poly) alkylene glycol (meth) acrylates such as propylene glycol (meth) acrylate; fluorinated alkyl (meth) acrylates such as octafluoropentyl (meth) acrylate; N, N-dimethylaminoethyl (meth) acrylate, N, Dialkylaminoalkyl (meth) acrylates such as N-diethylaminoethyl (meth) acrylate; allyl (meth) acrylate, 1,3-butanedio Glycol mono (meth) acrylates such as (meth) acrylate, 1,4-butanediol (meth) acrylate, 1,6-hexanediol (meth) acrylate, 3-methylpentanediol (meth) acrylate; (meth) acryloyl morpho Monofunctional (meth) acrylate compounds such as phosphorus; 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, hydroxypivalate ester neopentyl glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, 1,3-bis (hydroxyethyl) -5,5- Dimethylhydantoin di (meth) acrylate, α, ω-di (meth) acrylbisdiethylene glycol phthalate, trimethylolpropane tri (meth) acrylate, pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, di Pentaerythritol monohydroxypenta (meth) acrylate, 2-hydroxyethyl (meth) acryloyl phosphate, trimethylolpropane tri (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol Di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, diacryloxyethylphospho Examples thereof include multifunctional (meth) acrylates such as sulfate. Moreover, what has vinyl groups, such as (alpha), (omega) -tetraallyl bistrimethylol propane tetrahydrophthalate, N-vinyl pyrrolidone, N-vinyl caprolactam, can also be used. These can be used alone or in combination of two or more. Also,

  In the photopolymerizable resin composition of this embodiment, it is preferable to use the (meth) acrylate compound which has an acryloyl group or a methacryloyl group among the above. By containing such a photopolymerizable monomer, the photopolymerizable resin composition is more reliably improved in workability such as lowering the viscosity more reliably and improving handling properties.

  (C) Examples of the photopolymerization initiator include a carbonyl photopolymerization initiator, a sulfide photopolymerization initiator, a quinone photopolymerization initiator, an azo photopolymerization initiator, a sulfochloride polymerization initiator, and a thioxanthone light. Examples thereof include a polymerization initiator, a peroxide photopolymerization initiator, and isoamyl o-dimethylaminobenzoate.

  Examples of the carbonyl 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, 4,4′-dichlorobenzophenone, 4,4′-bisdiethylaminobenzophenone, Michler's ketone, benzoin methyl ether, benzoin isobutyl ether, benzoin n-butyl ether, Benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenol ) -2-hydroxy-2-methylpropan-1-one, methyl benzoyl formate, 2,2-diethoxyacetophenone, 4-N, N'-dimethyl acetophenone, and the like.

  Examples of the sulfide photopolymerization initiator include diphenyl disulfide, dibenzyl disulfide, tetraethylthiuram disulfide, and tetramethylammonium monosulfide. Examples of the quinone photopolymerization initiator include benzoquinone and anthraquinone. Examples of the azo photopolymerization initiator include azobisisobutyronitrile, 2,2-azobispropane, hydrazine, and the like.

  Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, and 2-methylthioxanthone.

  Examples of the peroxide photopolymerization initiator include benzoyl peroxide and di-tert-butyl peroxide.

  Said photoinitiator can be used individually by 1 type or in combination of 2 or more types.

(A) component contained in the photocurable resin composition of the present embodiment, the component (B), and (C) For the content of the component, the component (A) of the mass M _A and the component (B) of mass M the ratio _M a / _{M B} and _B is preferably from 95 / 5-40 / 60, and more preferably 90 / 10-60 / 40. The M _{A /} M _B is more than 95/5, the working viscosity of the photocurable resin composition becomes higher tends to decrease. On the other hand, the M A _/ M _B, is less than 40/60, curability of the photocurable resin composition, and tends to elongation and strength of the cured coating film becomes insufficient.

  Moreover, about the content rate of (C) component, it is preferable that it is 1-10 mass parts with respect to a total of 100 mass parts of (A) component and (B) component. When the content ratio of the component (C) is less than 1 part by mass, the photocurability tends to be insufficient, and when it exceeds 10 parts by mass, the characteristics (hardness, strength, Flexibility (elongation rate, etc.) tends to decrease.

  Moreover, the photocurable resin composition of the present embodiment uses (B) acryloylmorpholine as a photopolymerizable monomer having a reactive unsaturated group, and 70 parts by mass of the urethane compound as the component (A), (B) When it contains 30 mass parts of acryloyl morpholine as a component, it is preferable that the viscosity in 25 degreeC shall be 1500-3500 mPa * s. The viscosity of the photocurable resin composition can be measured using, for example, a BH or BL type rotational viscometer.

  The photocurable resin composition having the above viscosity is excellent in workability even when no solvent is used, and further contains the above urethane compound and acryloylmorpholine as the component (B) in the above proportion. By doing this, it is possible to more reliably form a cured coating film that is sufficiently excellent in the curability of the coating film surface and the adhesion to the substrate and that satisfies the elongation and strength at a higher level.

  Next, an embodiment of the paint of the present invention will be described.

  The coating material of this embodiment comprises the photocurable resin composition of this embodiment described above. In addition to the above-mentioned photocurable resin composition, the coating material of this embodiment includes a natural or synthetic polymer substance, a filler, an extender pigment, a pigment, a polymerization inhibitor, a leveling agent, a modified agent, if necessary. A quality agent, a plasticizer, etc. can be added.

  Examples of natural polymer substances include fats and oils, and specific examples include linseed oil, tung oil, soybean oil, castor oil, and epoxidized oil.

  Synthetic polymer materials include, 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 Examples thereof include resins, polydiene elastomers, saturated polyesters, saturated polyethers, and cellulose derivatives. Examples of cellulose derivatives 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, and zinc stearate.

  Examples of the pigment include zinc white, bengara, and azo pigments.

  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 polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, polyether-modified methylalkylpolysiloxane copolymer, aralkyl-modified methylalkylpolysiloxane copolymer, and the like. .

  Examples of the plasticizer include dihydric alcohol ester plasticizers, other ester plasticizers, epoxy plasticizers, and polyester plasticizers. Examples of the dihydric alcohol ester plasticizer include diethylene glycol dibenzoate and triethylene glycol-di-2-ethylbutyrate. Other ester plasticizers include, for example, tributyl phosphate, triphosphate phosphate. Phenyl, tri-2-ethylhexyl phosphate, dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl azelate, dibutyl sebacate, dioctyl sebacate, diethyl phthalate, dibutyl phthalate, di-phthalate Examples include n-octyl and butyl oleate.

  The photocurable resin composition of the present embodiment contained in the paint of the present embodiment has excellent curability on the surface of the coating film, has sufficient elongation and mechanical strength, and is sufficiently cured with excellent adhesion to the substrate. While being able to form a coating film, it can have a viscosity (sufficiently low viscosity) sufficiently excellent in workability. Therefore, the paint of this embodiment can be used as a solventless paint that does not use a solvent. However, an organic solvent may be used as necessary. As an organic solvent, what was illustrated as an organic solvent used in order to obtain the above-mentioned (A) urethane compound is mentioned, for example.

  The blending ratio of the above-mentioned natural or synthetic polymer substances, fillers, extender pigments, pigments, polymerization inhibitors, leveling agents, modifiers, plasticizers and organic solvents is appropriately selected depending on the application of the paint and is particularly limited. Although it is not a thing, it is preferable that the total amount of each of these components shall be 0.01 mass%-50 mass% with respect to the mass of a coating material.

  As a method for obtaining the coating material of the present embodiment, the photocurable resin composition of the present embodiment is a known method such as, for example, a paint shaker method, a roll mill method, a sand mill method, a disperser method, a kneader method, or a high-speed impeller mill method. A method of forming a paint using the method is mentioned.

  The paint of this embodiment can be used for painting according to a normal painting method. For coating, for example, an air spray method, an airless spray machine, an electrostatic coating machine, dipping, a roll coating machine, a brush, or the like can be used.

  In addition, the coating material of this embodiment is used for coating metal materials such as iron and aluminum, calcium silicate plates, pulp cement plates, lightweight concrete plates, asbestos cement plates, inorganic building materials such as mortar, wood, paper, plastic substrates, etc. After coating, the coating film can be cured by irradiating the coating film with ultraviolet light using a high pressure mercury lamp, a metal halide lamp or the like as a light source. Moreover, the cured coating film to be formed has a sufficiently high strength and a sufficiently high elongation rate, and is sufficiently excellent in adhesion to the above-mentioned base material (particularly wood). Furthermore, since the coating material of this embodiment can obtain such excellent characteristics using the above-described relatively inexpensive material, it is also excellent in cost performance.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

<Synthesis of urethane acrylate>
(Synthesis Example 1)
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 40.6 parts by mass of 2-hydroxyethyl acrylate (2-HEA), ethylene oxide and 269.6 parts by mass of copolymerized polyether polyol (manufactured by Toho Chemical Co., Ltd., trade name “Pepol B-124F”, number average molecular weight: about 2000), copolymer of ethylene oxide and propylene oxide Polyether polyol (Nippon Yushi Co., Ltd., trade name “Pronon # 102”, number average molecular weight: about 1000) 67.7 parts by mass, polyethylene glycol (Nippon Yushi Co., Ltd., trade name “PEG400”, number average) Molecular weight: about 400) 23.3 parts by mass, diethylene glycol (DEAL) 6.8 parts by mass, hydroquinone monomer 0.2 parts by mass of ruether and 0.1 parts by mass of dibutyltin dilaurate (trade name “L101”, manufactured by Tokyo Fine Chemical Co., Ltd.) were charged, heated to 70 ° C. and then kept at 70 to 75 ° C., tolylene diisocyanate ( 81.2 parts by mass of Nippon Polyurethane Co., Ltd. (trade name “Coronate T-80”) was uniformly dropped over 3 hours to cause a reaction. The reaction was continued for about 5 hours after completion of the dropping, and the reaction was terminated after confirming that the isocyanate had disappeared by IR measurement. Thus, urethane acrylate compound 1 having a solid content of about 100% was obtained.

(Synthesis Example 2)
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling tube and air gas introduction tube, 50.3 parts by mass of 2-hydroxyethyl acrylate (2-HEA), ethylene oxide and Copolymerized polyether polyol with propylene oxide (manufactured by Toho Chemical Co., Ltd., trade name “Pepol B-124F”, number average molecular weight: about 2000) 143.2 parts by mass, copolymerized system of ethylene oxide and propylene oxide Polyether polyol (manufactured by Toho Chemical Co., Ltd., “Pepol B-064”, number average molecular weight: about 1000) 157.8 parts by mass, polyethylene glycol (manufactured by NOF Corporation, trade name “PEG400”, number average molecular weight : About 400) 28.9 parts by mass, diethylene glycol (DEAL) 8.4 parts by mass, hydroquinone monomethyl 0.2 parts by mass of ether and 0.1 parts by mass of dibutyltin dilaurate (trade name “L101” manufactured by Tokyo Fine Chemical Co., Ltd.) were charged, heated to 70 ° C. and then kept at 70 to 75 ° C., tolylene diisocyanate ( 100.7 parts by mass of Nippon Polyurethane Co., Ltd. (trade name “Coronate T-80”) was uniformly dropped over 3 hours and reacted. The reaction was continued for about 5 hours after completion of the dropwise addition, and the reaction was terminated after confirming that the isocyanate had disappeared by IR measurement. Thus, a urethane acrylate compound 2 having a solid content of about 100% was obtained.

(Synthesis Example 3)
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 37.7 parts by mass of 2-hydroxyethyl acrylate (2-HEA), ethylene oxide and Copolyether polyether polyol with propylene oxide (trade name “Pepol B-124F”, number average molecular weight: about 2000) manufactured by Toho Chemical Co., Ltd., 250.3 parts by mass, polypropylene glycol (manufactured by NOF Corporation, trade name) "Uniol D-2000", number average molecular weight: about 2000) 97.9 parts by mass, polyethylene glycol (manufactured by NOF Corporation, trade name "PEG400", number average molecular weight: about 400) 21.7 parts by mass, diethylene glycol (DEAL) 6.3 parts by mass, hydroquinone monomethyl ether 0.2 parts by mass and dibutyltin dilaurate (Tokyo Fine Chemical Co., Ltd., trade name “L101”) 0.1 parts by weight was charged, heated to 70 ° C. and then kept at 70-75 ° C., tolylene diisocyanate (made by Nippon Polyurethane Co., Ltd., trade name “CORONATE T −80 ”) 75.4 parts by mass were uniformly added dropwise over 3 hours to react. The reaction was continued for about 5 hours after the completion of the dropwise addition, and the reaction was terminated by confirming that the isocyanate had disappeared by IR measurement. Thus, urethane acrylate compound 3 having a solid content of about 100% was obtained.

(Synthesis Example 4)
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 38.7 parts by mass of 2-hydroxyethyl acrylate (2-HEA), ethylene oxide and 110.1 parts by mass of propylene oxide copolymer polyether polyol (manufactured by Toho Chemical Co., Ltd., trade name “Pepol B-124F”, number average molecular weight: about 2000), polypropylene glycol (manufactured by NOF Corporation, trade name) "Uniol D-2000", number average molecular weight: about 2000) 234.4 parts by mass, polyethylene glycol (manufactured by NOF Corporation, trade name "PEG400", number average molecular weight: about 400) 22.2 parts by mass, diethylene glycol (DEAL) 6.5 parts by mass, hydroquinone monomethyl ether 0.2 parts by mass and dibutyltin dilaure Toluene (produced by Tokyo Fine Chemical Co., Ltd., trade name “L101”) is charged with 0.1 parts by mass, heated to 70 ° C. and kept at 70 to 75 ° C., and tolylene diisocyanate (made by Nippon Polyurethane Co., Ltd., trade name “Coronate” T-80 ") 75.4 parts by mass were uniformly added dropwise over 3 hours to react. The reaction was continued for about 5 hours after completion of the dropwise addition, and the reaction was terminated by confirming that the isocyanate had disappeared by IR measurement. Thus, urethane acrylate compound 4 having a solid content of about 100% was obtained.

(Synthesis Example 5)
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 34.8 parts by mass of 2-hydroxyethyl acrylate (2-HEA), ethylene oxide and Copolymerized polyether polyol with propylene oxide (manufactured by Toho Chemical Co., Ltd., trade name “Pepol B-124F”, number average molecular weight: about 2000) 140.5 parts by mass, copolymerized system of ethylene oxide and propylene oxide Polyether polyol (manufactured by NOF Corporation, trade name “Pronon # 102”, number average molecular weight: about 1000) 77.3 parts by mass, polypropylene glycol (manufactured by NOF Corporation, trade name “Uniol D-2000”, number Average molecular weight: about 2000) 140.5 parts by mass, polyethylene glycol (Nippon Yushi Co., Ltd., trade name “PE” 400 ”, number average molecular weight: about 400) 10.0 parts by mass, diethylene glycol (DEAL) 3.0 parts by mass, hydroquinone monomethyl ether 0.2 parts by mass and dibutyltin dilaurate (trade name“ L101 ”manufactured by Tokyo Fine Chemicals Co., Ltd.) )) 0.1 parts by mass, heated to 70 ° C. and kept at 70 to 75 ° C., 77.4 parts by mass of tolylene diisocyanate (product name “Coronate T-80” manufactured by Nippon Polyurethane Co., Ltd.) for 3 hours The solution was uniformly dropped and reacted. The reaction was continued for about 5 hours after completion of the dropwise addition, and the reaction was terminated after confirming that the isocyanate had disappeared by IR measurement. Thus, urethane acrylate compound 5 having a solid content of about 100% was obtained.

(Synthesis Example 6)
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 32.3 parts by mass of 2-hydroxyethyl acrylate (2-HEA), ethylene oxide and Copolymerized polyether polyol with propylene oxide (manufactured by Toho Chemical Co., Ltd., trade name “Pepol B-124F”, number average molecular weight: about 2000) 112.4 parts by mass, copolymerized system of ethylene oxide and propylene oxide Polyether polyol (Nippon Yushi Co., Ltd., trade name “Pronon # 102”, number average molecular weight: about 1000) 71.8 parts by mass, polypropylene glycol (Nippon Yushi Co., Ltd., trade name “Uniol D-2000, number average” Molecular weight: about 2000) 195.8 parts by mass, polyethylene glycol (manufactured by NOF Corporation, trade name “PEG” 00 ”, number average molecular weight: about 400) 9.3 parts by mass, diethylene glycol (DEAL) 3.0 parts by mass, hydroquinone monomethyl ether 0.2 parts by mass and dibutyltin dilaurate (manufactured by Tokyo Fine Chemical Co., Ltd., trade name“ L101 ”) )) 0.1 parts by mass, heated to 70 ° C. and kept at 70-75 ° C., 64.7 parts by mass of tolylene diisocyanate (product name “Coronate T-80” manufactured by Nippon Polyurethane Co., Ltd.) for 3 hours The solution was uniformly dropped and reacted. The reaction was continued for about 5 hours after the completion of the dropwise addition, and the reaction was terminated by confirming that the isocyanate had disappeared by IR measurement. Thus, urethane acrylate compound 6 having a solid content of about 100% was obtained.

(Synthesis Example 7)
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 25.6 parts by mass of 2-hydroxyethyl acrylate (2-HEA), ethylene oxide and 412.5 parts by mass of copolymer polyether polyol with propylene oxide (manufactured by Toho Chemical Co., Ltd., trade name “Pepol B-124F”, number average molecular weight: about 2000), 0.2 part by mass of hydroquinone monomethyl ether and dibutyl 0.1 parts by mass of tin dilaurate (trade name “L101” manufactured by Tokyo Fine Chemical Co., Ltd.) was charged, heated to 70 ° C. and then kept at 70 to 75 ° C., and tolylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., product name “ Coronate T-80 ") 51.2 parts by mass was uniformly added dropwise over 3 hours to react. The reaction was continued for about 5 hours after completion of the dropwise addition, and the reaction was terminated by confirming that the isocyanate had disappeared by IR measurement. Thus, urethane acrylate compound 7 having a solid content of about 100% was obtained.

(Synthesis Example 8)
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 58.9 parts by mass of 2-hydroxyethyl acrylate (2-HEA), ethylene oxide and Copolymer-based polyether polyol with propylene oxide (manufactured by Toho Chemical Co., Ltd., trade name “Pepol B-124F”, number average molecular weight: about 2000) 204.7 parts by mass, polyethylene glycol (manufactured by NOF Corporation, Product name “PEG400”, number average molecular weight: about 400) 98.1 parts by mass, diethylene glycol (DEAL) 9.9 parts by mass, hydroquinone monomethyl ether 0.2 parts by mass and dibutyltin dilaurate (manufactured by Tokyo Fine Chemical Co., Ltd., product) Name “L101”) 0.1 parts by mass, heated to 70 ° C. and kept at 70 to 75 ° C. Emissions diisocyanate (Nippon Polyurethane Co., Ltd., trade name "Coronate T-80") and 117.7 parts by weight of uniformly dropped to react for 3 hours. The reaction was continued for about 5 hours after the completion of the dropping, and the reaction was terminated by confirming that the isocyanate had disappeared by IR measurement, whereby a urethane acrylate compound 8 having a solid content of about 100% was obtained.

(Synthesis Example 9)
After introducing air gas into a reaction vessel equipped with a stirrer, a thermometer, a cooling pipe and an air gas introduction pipe, 89.5 parts by mass of 2-hydroxyethyl acrylate (2-HEA), polyethylene glycol ( Product name “PEG400”, number average molecular weight: about 400) 205.8 parts by mass, diethylene glycol (DEAL) 15.0 parts by mass, hydroquinone monomethyl ether 0.2 parts by mass and dibutyltin dilaurate (Tokyo) 0.1 parts by mass of Fine Chemical Co., Ltd., trade name “L101”) was charged, heated to 70 ° C. and then kept at 70 to 75 ° C., tolylene diisocyanate (trade name “Coronate T-80, manufactured by Nippon Polyurethane Co., Ltd.” ]) 179.0 parts by mass were uniformly added dropwise over 3 hours to react. The reaction was continued for about 5 hours after the completion of the dropwise addition, and the reaction was terminated by confirming that the isocyanate had disappeared by IR measurement. Thus, a urethane acrylate compound 9 having a solid content of about 100% was obtained.

(Synthesis Example 10)
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 27.6 parts by mass of 2-hydroxyethyl acrylate (2-HEA), polypropylene glycol ( Product name “Uniol D-2000, number average molecular weight: about 2000” 406.4 parts by mass, hydroquinone monomethyl ether 0.2 parts by mass and dibutyltin dilaurate (manufactured by Tokyo Fine Chemical Co., Ltd., product name “L101” )) 0.1 parts by mass, heated to 70 ° C. and kept at 70 to 75 ° C., 55.3 parts by mass of tolylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name “Coronate T-80”) for 3 hours The solution was uniformly dropped and reacted. The reaction was continued for about 5 hours after completion of the dropwise addition, and the reaction was terminated by confirming that the isocyanate had disappeared by IR measurement. Thus, a urethane acrylate compound 10 having a solid content of about 100% was obtained.

  Table 1 shows a summary of the blending ratio of each component in Synthesis Examples 1 to 10 expressed in terms of moles.

Example 1
As a photopolymerizable monomer having urethane acrylate compound 1 obtained in Synthesis Example 1 and one or more photocurable curable unsaturated double bonds in one molecule, acryloylmorpholine (manufactured by Kojin Co., Ltd., 1% hydroxycyclohexyl phenyl ketone (manufactured by Ciba Specialty Chemicals, trade name “Irgacure 184”) as a photopolymerization initiator is blended with 30% by mass of a product name “ACMO”). The photocurable resin composition was prepared by mix | blending 3 mass% with respect to the total amount with a monomer, and mixing uniformly.

(Example 2)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the urethane acrylate compound 2 obtained in Synthesis Example 2 was used instead of the urethane acrylate compound 1.

(Example 3)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the urethane acrylate compound 3 obtained in Synthesis Example 3 was used instead of the urethane acrylate compound 1.

(Example 3)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the urethane acrylate compound 3 obtained in Synthesis Example 3 was used instead of the urethane acrylate compound 1.

Example 4
A photocurable resin composition was prepared in the same manner as in Example 1 except that the urethane acrylate compound 4 obtained in Synthesis Example 4 was used instead of the urethane acrylate compound 1.

(Example 5)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the urethane acrylate compound 5 obtained in Synthesis Example 5 was used instead of the urethane acrylate compound 1.

(Example 6)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the urethane acrylate compound 6 obtained in Synthesis Example 6 was used instead of the urethane acrylate compound 1.

(Comparative Example 1)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the urethane acrylate compound 7 obtained in Synthesis Example 7 was used instead of the urethane acrylate compound 1.

(Comparative Example 2)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the urethane acrylate compound 8 obtained in Synthesis Example 8 was used instead of the urethane acrylate compound 1.

(Comparative Example 3)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the urethane acrylate compound 9 obtained in Synthesis Example 9 was used instead of the urethane acrylate compound 1.

(Comparative Example 4)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the urethane acrylate compound 10 obtained in Synthesis Example 10 was used instead of the urethane acrylate compound 1.

<Performance evaluation of photocurable resin composition>
(viscosity)
The viscosity of each curable resin composition obtained in the above Examples and Comparative Examples was measured with a BH or BL type rotational viscometer.

(Appearance of coating film)
Each curable resin composition obtained in the above Examples and Comparative Examples is applied to a glass plate as a base material using an applicator 100 so that the dry film thickness is about 30 to 50 μm to form a coating film. did. The appearance of this coating film was visually evaluated.

Next, an ultraviolet ray irradiation device (6 kW, 80 w / cm × 2 lamps, manufactured by Nihon Battery Co., Ltd.) is used for the glass plate on which the above-mentioned coating film is formed, one 80 w / cm high-pressure mercury lamp, irradiation distance An evaluation test plate on which a cured coating film was formed by irradiation with ultraviolet rays under conditions of 15 cm and a conveyor speed of 10 m / min (corresponding to a UV irradiation amount of 100 mJ / cm ² ) was obtained. In addition, as a UV measuring apparatus, Topcon Industrial UV Checker UV R-T35 was used, and the measurement wavelength range was about 300 to 390 nm. Thus, the following (1)-(3) evaluation was performed about the coating film of the test plate for evaluation obtained.

(1) UV curable The ultraviolet irradiation amount (mJ / cm < ² >) until the coating-film surface reached finger touch hardening was measured.

(2) Appearance of cured coating film The appearance of the obtained cured coating film was visually evaluated.

(3) Pencil hardness Based on JISK5400, the pencil hardness which does not leave a crack trace on the coating-film surface was evaluated.

In addition, each curable resin composition obtained in the above Examples and Comparative Examples was applied to a glass plate as a base material using an applicator so that the dry film thickness was about 30 to 50 μm, and then irradiated with ultraviolet rays. Using a device (6 kW, 80 w / cm × 2 lamps, manufactured by Nippon Battery Co., Ltd.), one 80 w / cm high-pressure mercury lamp, an irradiation distance of 15 cm, and a conveyor speed of 10 m / min (corresponding to a UV irradiation amount of 100 mJ / cm ²⁾ ) Was peeled off from the cured coating film formed by irradiating with ultraviolet rays to prepare a cured film having a thickness of about 30 to 50 μm. The cured film thus obtained was evaluated for the following tensile elongation and tensile strength.

(Tensile elongation and tensile strength of cured film)
The produced cured film was cut into a strip having a length of 50 mm and a width of 10 mm at an environmental temperature of 25 ° C. to obtain a test piece. The test piece was pulled in a one-way / two-way refrigerator type constant temperature bath (manufactured by Shimadzu Corp.) at an environmental temperature of 25 ° C. with a test span of 50 mm and a tensile speed of 10 mm / min until the cured film was broken. From the elongation (mm) and strength (N), elongation (%) and tensile strength were determined by the following calculation formula.
Elongation rate (%) = {[Elongation at break (mm)] / [Test span (mm)]} × 100
The test span was 50 mm.
Tensile strength (N / cm ² ) = [strength at break (N)] / (A × B)
In addition, A means the width (cm) of the cured film test piece, and B means the thickness (cm) of the cured film.

  The evaluation results are shown in Table 2.

As shown in Table 2, the photocurable resin compositions of Examples 1 to 6 have a viscosity of 3500 mPa · s or less and a sufficiently low viscosity, and one 80 W / cm high-pressure mercury lamp, an irradiation distance of 15 cm, coating the surface with four irradiation (UV irradiation of about 200 mJ / cm ²⁾ in the conveyor speed 25 m / min conditions (one dose about 50 mJ / cm ²⁾ is fully cured has sufficient curability Furthermore, the cured coating film was confirmed to have a breaking strength of 600 N / cm ² or more, an elongation of 100% or more, sufficient strength and flexibility, and good adhesion to the substrate. . It was also confirmed that the appearance and hardness of the cured coating film sufficiently satisfied the practical level.

  On the other hand, the photocurable resin composition of Comparative Example 1 had a high viscosity and insufficient workability. Moreover, the photocurable resin compositions of Comparative Examples 2 and 3 have high viscosity and insufficient workability, and further, the elongation is less than 100%, and partly peels between the substrate and the cured coating film. It was observed. Further, the photocurable resin composition of Comparative Example 4 had a sufficiently low viscosity of 3500 mPa · s or less, but the curability of the coating film was insufficient, and the cured coating film formed The breaking strength and elongation were also insufficient, and partial peeling was observed between the substrate and the cured coating film.

Claims (9)

(A) a urethane compound, (B) a photopolymerizable monomer having a reactive unsaturated group, and (C) a photopolymerization initiator,
The urethane compound is
(A) an isocyanate compound having two isocyanate groups in one molecule;
(B) a polyoxyalkylene glycol having a number average molecular weight of more than 1000 and not more than 2500;
(C) alkylene glycol or polyoxyalkylene glycol having a number average molecular weight of 62 or more and 1000 or less,
(D) an ethylenically unsaturated compound having a hydroxyl group;
The ratio of the number of moles of the component (b) to the number of moles of the component (c) is 1 or more, and the component (b), the component (c) and the component (a) with respect to the isocyanate group of the component (a) d) A photocurable resin composition obtained by mixing and reacting so that the equivalent ratio of hydroxyl groups of the component is 1.0 to 1.1. The said (b) component is a photocurable resin composition of Claim 1 containing the polyoxyalkylene glycol represented by following General formula (1).

(In the formula (1), x, y and z are positive integers, and the following formulas (I) and (II);
0.1 ≦ [(x + z) / y] ≦ 1.0 (I)
15 ≦ (x + y + z) ≦ 40 (II)
Meet. ) The photocurable resin composition according to claim 2, wherein the component (b) further contains a polyoxyalkylene glycol represented by the following general formula (2).

(In formula (2), R ¹ represents hydrogen or a methyl group, and n is a positive integer.) The component (c) contains polyoxyalkylene glycol represented by the following general formula (3) and / or alkylene glycol or polyoxyalkylene glycol represented by the following general formula (4). The photocurable resin composition according to any one of the above.

(In formula (3), p, q and r are positive integers.)

(In Formula (4), R ² represents hydrogen or a methyl group, and m is a positive integer.) The ratio M _OH / M _a between the number of moles M _{OH of the} hydroxyl group of the component (d) and the number of moles M _a of the isocyanate compound of the component (a) is 3 / 5-1. The photocurable resin composition according to any one of the above. The number average molecular weight of the said urethane compound is 1000-4000, and ratio of the weight average molecular weight of the said urethane compound with respect to the said number average molecular weight is 3.0 or less, The any one of Claims 1-5. Photocurable resin composition. Wherein (A) the mass _{M A} component (B) ratio _M A / _{M B} of the components of the mass _{M B} is a 95 / 5-40 / 60, and the content of the component (C) The photocurable resin composition according to any one of claims 1 to 6, which is 1 to 10 parts by mass with respect to 100 parts by mass in total of the component (A) and the component (B). It contains 70 parts by mass of the urethane compound and 30 parts by mass of acryloylmorpholine as the component (B), and the viscosity at 25 ° C. is 1500 to 3500 mPa · s. The photocurable resin composition as described. The coating material containing the photocurable resin composition of any one of Claims 1-8.