JP7073816B2 - An active energy ray-curable resin composition, a coating agent using the same, and a sheet. - Google Patents

Description

The present invention relates to an active energy ray-curable resin composition. More specifically, when a cured coating film is formed, the present invention has a large elongation of the coating film, has a high Young rate, and is also excellent in flexibility. It is a sex resin composition, and in particular, it relates to an active energy ray curable resin composition which can be used without blending an organic solvent, a coating agent using the same, and a sheet.

Conventionally, plastic films have been widely used for optical members such as liquid crystal displays, and acetylated cellulose resin films and polyethylene terephthalate resin films have been used because of their excellent optical properties such as workability and transparency. .. However, since these plastic films have a drawback that the surface is easily scratched, they are usually used by applying a hard coat agent for the purpose of imparting hardness and scratch resistance. As this hard coat agent, an active energy ray-curable resin composition is often used because of its excellent adhesion to a plastic film, high curing speed, and improved productivity. There is.

In addition, the hard coat agent is less likely to curl due to shrinkage of the cured coating film (low curl property) and is cured because it is used for improving processing suitability such as punching and for flexible displays that have been developed in recent years. It is required that cracks and the like are unlikely to occur even when the plastic film on which the coating film is formed is bent (high flexibility).

In order to meet such demands, the applicant includes a urethane (meth) acrylate compound having no structural moiety derived from the polyol component and a urethane (meth) acrylate compound having a structural moiety derived from the polyol component. In the composition, the urethane (meth) acrylate compound having no structural moiety derived from the polyol component has an isocyanurate skeleton, has a high concentration of ethylenically unsaturated groups, and has a structural moiety derived from the polyol component. The content of the urethane (meth) acrylate compound having an alicyclic structure, a low ethylenically unsaturated group concentration, and no structural site derived from the polyol component is derived from the polyol component. We have already proposed an active energy ray-curable resin composition that can solve the above-mentioned problems by making the content of the urethane (meth) acrylate compound having a structural portion equal to or higher than that of the compound (Patent Document 1).

Further, in recent years, from the viewpoint of the stability of the coating material and the response to environmental problems, the use of a solvent-free active energy ray-curable resin composition without using an organic solvent has been studied. Here, when a urethane (meth) acrylate-based compound is used as the active energy ray-curable resin, viscosity adjustment, surface hardness adjustment, coating film flexibility imparting, substrate adhesion imparting, curing shrinkage relaxation, and curing are performed. Speed adjustment, refractive index adjustment, durability (eg, water resistance, heat resistance, etc.), coating surface properties (eg, water repellency, hydrophilicity, slip property, antistatic property, etc.), etc. For various purposes, it is used by diluting it with a diluting monomer.

Under such circumstances, the applicant is an activity of a solvent-free active energy ray-curable resin composition capable of forming a coating film having good elongation characteristics and a high Young's ratio and having high strength. The energy ray-curable resin composition includes a urethane (meth) acrylate compound which is a reaction product of a hydroxyl group-containing (meth) acrylate compound, a polyvalent isocyanate compound and a polyol compound containing a low molecular weight polyol, and ethylenically unsaturated. We have already proposed an active energy ray-curable resin composition containing a monomer containing one group (Patent Document 2).

JP-A-2015-199921 Japanese Unexamined Patent Publication No. 2016-194061

However, the coating film made of the resin composition described in Patent Document 1 has not been sufficiently studied from the viewpoint of flexibility, and the coating film is cracked or broken when used under stricter conditions. There are still concerns about such things as doing so.
Further, the coating film made of the resin composition described in Patent Document 2 has not been sufficiently studied from the viewpoint of flexibility, and there is a concern that breakage may occur when the coating film is bent. ..
Therefore, it is required to provide a resin having good elongation characteristics, high Young's modulus, characteristics such as being able to form a coating film having high strength, and good flexibility.

The present invention has been made in view of such circumstances, and when it is used as a cured coating film, it has high transparency, good elongation characteristics, high Young's modulus, high strength, and excellent flexibility. It is an object of the present invention to provide an active energy ray-curable resin composition capable of forming the above, a coating agent using the same, and a sheet.

The present inventors have conducted intensive studies to solve the above-mentioned problems. In the process of the research, it corresponds to two or three components selected from three components of polyester urethane (meth) acrylate, polycarbonate urethane (meth) acrylate, and urethane (meth) acrylate containing no polyol component. I recalled using it in combination with urethane (meth) acrylate. Then, as the isocyanate used as the material of the polyester-based urethane (meth) acrylate and the polycarbonate-based urethane (meth) acrylate, a polyvalent isocyanate containing an alicyclic structure is used, and further, the polyester-based urethane (meth) acrylate and the polycarbonate-based urethane are used. As a polyol used as a material for (meth) acrylate, it was examined to use a combination of a low molecular weight polyol having a number average molecular weight of 300 or less and a high molecular weight polyol having a number average molecular weight of 500 to 20,000. As a result, it has been found that the above object can be achieved because it has the characteristics of being transparent and capable of forming a cured coating film having an excellent balance of high elongation, high strength and high flexibility, and has reached the present invention. did.

That is, the present invention uses, first, an active energy ray-curable resin composition containing a urethane (meth) acrylate corresponding to two or three components selected from the following three components (A) to (C). It is a summary.
(A) Urethane (meth) acrylate which is a reaction product of alicyclic structure-containing polyhydric isocyanate (a1), polyol (a2), and hydroxyl group-containing (meth) acrylate (a3), wherein the polyol (a2) is. A urethane (meth) acrylate containing a low molecular weight polyol (a2-1) having a number average molecular weight of 300 or less and a high molecular weight polyester-based polyol (a2-2) having a number average molecular weight of 500 to 20,000.
(B) A urethane (meth) acrylate which is a reaction product of a polyhydric isocyanate (b1) containing an alicyclic structure, a polyol (b2), and a hydroxyl group-containing (meth) acrylate (b3), wherein the polyol (b2) is a reaction product. A urethane (meth) acrylate containing a low molecular weight polyol (b2-1) having a number average molecular weight of 300 or less and a high molecular weight polycarbonate-based polyol (b2-2) having a number average molecular weight of 500 to 20,000.
(C) Urethane (meth) acrylate which is a reaction product of polyisocyanate (c1) and hydroxyl group-containing (meth) acrylate (c2).

The second gist of the present invention is a coating agent containing the above-mentioned active energy ray-curable resin composition. Further, the third gist of the present invention is a sheet made of a cured product of the above active energy ray-curable resin composition.

As described above, the active energy ray-curable resin composition of the present invention contains a two-component to three-component urethane (meth) acrylate selected from the three components (A) to (C). Therefore, the coating film formed by the active energy ray-curable resin composition of the present invention, the coating film formed by the coating agent containing the active energy ray-curable resin composition of the present invention, and the present invention. The sheet made of the cured product of the active energy ray-curable resin composition has high transparency, good elongation characteristics, high Young rate, high strength, and excellent flexibility. Further, the coating film or the like formed by using the above-mentioned active energy ray-curable resin composition has excellent followability to the base material, and is also useful as a tough base material having elasticity. Further, since the coating film and the like have high transparency, little deterioration in physical properties at high temperature, and excellent chemical resistance, they can be used for various purposes utilizing these characteristics.

In particular, the active energy ray-curable resin composition contains at least urethane (meth) acrylate (A), and is based on the low molecular weight polyol (a2-1) and the high molecular weight polyester in the urethane (meth) acrylate (A). When the ratio (a2-1 / a2-2) to the polyol (a2-2) is 1/99 to 50/50 in terms of weight, it is easier to impart a higher young rate and higher elongation, and the physical properties are improved. Can be fine-tuned.

Further, the active energy ray-curable resin composition contains at least urethane (meth) acrylate (B), and is based on the low molecular weight polyol (b2-1) and the high molecular weight polycarbonate in the urethane (meth) acrylate (B). When the ratio (b2-1 / b2-2) to the polyol (b2-2) is 1/99 to 50/50 in terms of weight, it is easier to impart a higher young rate and higher elongation, and the physical properties are improved. Can be fine-tuned.

Further, it is said that the hydroxyl group-containing (meth) acrylates (a3 and b3) in the urethane (meth) acrylates (A) and (B) are (meth) acrylates having one (meth) acryloyl group in the molecule. , An appropriate crosslinked structure can be imparted to the cured coating film, and extensibility can be imparted.

Further, when the active energy ray-curable resin composition further contains an ethylenically unsaturated monomer (D) having a glass transition temperature of 100 ° C. or higher when used as a homopolymer, a tougher coating film can be obtained. can.

Then, the ethylenically unsaturated monomer (D) contains at least one selected from the alicyclic structure-containing (meth) acrylate (d1) and the heterocyclic structure-containing (meth) acrylate (d2). Then, a higher young rate and a higher elongation can be realized.

Further, the ethylenically unsaturated monomer (D) contains an alicyclic structure-containing (meth) acrylate (d1) and a heterocyclic structure-containing (meth) acrylate (d2), and the content ratio (d1 / d2) thereof is the weight. When the ratio is 99/1 to 1/99, high flexibility can be obtained while achieving a high young rate and high elongation.

Further, when the content ratio of the ethylenically unsaturated monomer (D) is 100 to 400 parts by weight with respect to 100 parts by weight of the total amount of the urethane (meth) acrylates (A) to (C), it is more bent. Become excellent in sex.

Next, embodiments of the present invention will be described in detail. However, the present invention is not limited to this embodiment.

The active energy ray-curable resin composition of the present invention (hereinafter, may be abbreviated as "resin composition") is a urethane corresponding to two or three components selected from the following three components (A) to (C). It contains (meth) acrylate. That is, a combination of (A) + (B), (A) + (C), (B) + (C), (A) + (B) + (C), and urethane (meth) corresponding to each component. ) The purpose is to use acrylate together. Among them, from the viewpoint of the action and effect of the present invention, the combination of (A) + (B) is preferably performed, and particularly preferably the combination of (A) + (B) + (C) is performed. Is. As the urethane (meth) acrylate corresponding to the same component, one type may be used alone, or two or more types may be used in combination.
(A) Urethane (meth) acrylate which is a reaction product of alicyclic structure-containing polyvalent isocyanate (a1), polyol (a2), and hydroxyl group-containing (meth) acrylate (a3), wherein the polyol (a2) is. A urethane (meth) acrylate containing a low molecular weight polyol (a2-1) having a number average molecular weight of 300 or less and a high molecular weight polyester-based polyol (a2-2) having a number average molecular weight of 500 to 20,000.
(B) A urethane (meth) acrylate which is a reaction product of a polyhydric isocyanate (b1) containing an alicyclic structure, a polyol (b2), and a hydroxyl group-containing (meth) acrylate (b3), wherein the polyol (b2) is a reaction product. A urethane (meth) acrylate containing a low molecular weight polyol (b2-1) having a number average molecular weight of 300 or less and a high molecular weight polycarbonate-based polyol (b2-2) having a number average molecular weight of 500 to 20,000.
(C) Urethane (meth) acrylate which is a reaction product of polyisocyanate (c1) and hydroxyl group-containing (meth) acrylate (c2).

In the resin composition of the present invention, when only the component (A) and the component (B) are used in combination, the weight ratio thereof is (A) :( B) = 95: 5 to 5:95. However, it is preferable from the viewpoint of the action and effect of the present invention, and more preferably from the same viewpoint, it is in the range of (A) :( B) = 90:10 to 10:90.
Further, when only the component (A) and the component (C) are used in combination, the weight ratio thereof is (A) :( C) = 99: 1 to 1:99, which is the effect of the present invention. From the viewpoint, it is preferable, and from the same viewpoint, it is more preferably in the range of (A) :( C) = 95: 5 to 5:95.
Further, when only the component (B) and the component (C) are used in combination, the weight ratio thereof is (B) :( C) = 99: 1 to 1:99, which is the effect of the present invention. From the viewpoint, it is preferable, and from the same viewpoint, it is more preferably in the range of (B): (C) = 95: 5 to 5:95.
When all the three components (A) to (C) are contained, the component (A) is added to 100 parts by weight of the total amount of the three components (A) to (C) from the viewpoint of the action and effect of the present invention. The content of the component (B) is preferably 1 to 80 parts by weight, more preferably 10 to 60 parts by weight, and the content of the component (B) is preferably 1 to 80 parts by weight. The content is preferably in the range of 10 to 60 parts by weight, and the content of the component (C) is preferably 1 to 50 parts by weight, more preferably 3 to 30 parts by weight.

In the present invention, (meth) acrylic means acrylic or methacrylic, (meth) acryloyl means acryloyl or methacrylic, and (meth) acrylate means acrylate or methacrylate.

Next, the urethane (meth) acrylate corresponding to each of the above components (A) to (C) will be described.

<< Urethane (meth) acrylate (A) >>
The urethane (meth) acrylate (A) used in the present invention is a reaction generated by reacting with a polyvalent isocyanate (a1) containing an alicyclic structure, a polyol (a2), and a hydroxyl group-containing (meth) acrylate (a3). It is a thing. The polyol (a2) contains a low molecular weight polyol (a2-1) having a number average molecular weight of 300 or less and a high molecular weight polyester-based polyol (a2-2) having a number average molecular weight of 500 to 20,000. That is, the urethane (meth) acrylate (A) used in the present invention is a structural unit derived from the alicyclic structure-containing polyvalent isocyanate (a1) and a structural unit derived from a low molecular weight polyol (a2-1) having a number average molecular weight of 300 or less. , A compound having a structural unit derived from a high molecular weight polyester-based polyol (a2-2) having a number average molecular weight of 500 to 20,000 and a structural unit derived from a hydroxyl group-containing (meth) acrylate (a3). From the viewpoint of the action and effect of the present invention, 50% by weight or more, particularly 80% by weight or more of the total amount of the polyol (a2) is the low molecular weight polyol (a2-1) and the high molecular weight polyester-based polyol (a2-2). ), And it is more preferable that all of the above-mentioned polyol (a2) is composed of the above-mentioned low molecular weight polyol (a2-1) and the high-molecular-weight polyester-based polyol (a2-2).

[Alicyclic structure-containing multivalent isocyanate (a1)]
Examples of the alicyclic structure-containing polyvalent isocyanate (a1) include xylylene diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, and 1,4-bis (isocyanatomethyl). Isocyanatomethyl) cyclohexane, hydrogenated diphenylmethane diisocyanate and the like can be mentioned.
These may be used individually by 1 type, or may be used in combination of 2 or more type.

[Polyol (a2)]
As the above-mentioned polyol (a2), as described above, a low molecular weight polyol (a2-1) having a number average molecular weight of 300 or less and a high molecular weight polyester-based polyol (a2-2) having a number average molecular weight of 500 to 20,000. And are used in combination.

In particular, the ratio (a2-1 / a2-2) of the low molecular weight polyol (a2-1) to the high molecular weight polyester-based polyol (a2-2) is 1/99 to 50/50 by weight. However, it is preferable because it is easy to impart a higher Young's modulus and a higher elongation, and the physical properties can be finely adjusted. From the same viewpoint, the above ratio (weight ratio) is more preferably (a2-1 / a2-2) = 1.5 / 98.5 to 49/51, and particularly preferably (a2-1 / a2-). 2) = 2/98 to 48/52.

Further, the low molecular weight polyol (a2-1) is a polyol having a number average molecular weight of 60 to 300, and the high molecular weight polyester-based polyol (a2-2) is a polyester-based polyol having a number average molecular weight of 500 to 20,000. It is preferable because it is easy to impart a higher young rate and a higher elongation, and the physical properties can be finely adjusted. From the same viewpoint, the low molecular weight polyol (a2-1) is a polyol having a number average molecular weight of 70 to 250, and the high molecular weight polyester-based polyol (a2-2) is a polyester having a number average molecular weight of 600 to 15,000. It is more preferable, and particularly preferably, the low molecular weight polyol (a2-1) is a polyol having a number average molecular weight of 80 to 200, and the high molecular weight polyester-based polyol (a2-2) is a number. This is the case of a polyester-based polyol having an average molecular weight of 700 to 10,000.

The number average molecular weight shall be the number average molecular weight calculated based on the hydroxyl value measured in accordance with JIS K 1557. Specifically, the hydroxyl value is measured and calculated as (56.1 × 1,000 × valence) / hydroxyl value [mgKOH / g] by the end group quantification method. In the above formula, the valence is the number of hydroxyl groups in one molecule.

Examples of the low molecular weight polyol (a2-1) include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, dimethylolpropane, neopentyl glycol, and 2,2-diethyl-1,3-. Propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-tetramethylenediol, 1,3-tetramethylenediol, 2-methyl-1,3-trimethylethylenediol, 1,5- Pentamethylenediol, 1,6-hexamethylenediol, 3-methyl-1,5-pentamethylenediol, 2,4-diethyl-1,5-pentamethylenediol, pentaerythritol diacrylate, 1,9-nonanediol, Aliper alcohols such as 2-methyl-1,3-hexanediol and 2-methyl-1,8-octanediol, and alicyclic diols such as 1,4-cyclohexanediol, cyclohexyldimethanol and tricyclodecanedimethanol. Glycols, bisphenols such as bisphenol A, sugar alcohols such as xylitol and sorbitol, and the like, and these can be used alone or in combination of two or more.
Among these, from the viewpoint of yellowing of the cured coating film, a compound having a structure free of aromatic rings and unsaturated groups is preferable, and aliphatic alcohols are particularly preferable, and neopentyl glycol is more preferable.

Examples of the high molecular weight polyester polyol (a2-2) include a condensation polymer of a polyhydric alcohol and a polyvalent carboxylic acid; a ring-opening polymer of a cyclic ester (lactone); a polyhydric alcohol and a polyvalent carboxylic acid. Examples thereof include reactants consisting of three types of components, an acid and a cyclic ester.

Examples of the polyvalent alcohol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,4-tetramethylenediol, 1,3-tetramethylenediol, and 2-methyl-1,3-tri. Methylenediol, 1,5-pentamethylenediol, neopentylglycol, 1,6-hexamethylenediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentamethylenediol, 2,4- Diethyl-1,5-pentamethylenediol, glycerin, trimethylolpropane, trimethylolethane, cyclohexanediols (1,4-cyclohexanediol, etc.), tricyclodecanedimethanol, bisphenols (bisphenol A, etc.), sugar alcohols (Xylitol, sorbitol, etc.) and the like.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids such as malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid and dodecandionic acid; 1,4. -Alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid; aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid, trimellitic acid and the like can be mentioned.

Examples of the cyclic ester include propiolactone, β-methyl-δ-valerolactone, ε-caprolactone and the like.

As the polyol (a2) as a whole, it is preferable to use a bifunctional (two hydroxyl groups) polyol, and further, a bifunctional polyol and a trifunctional polyol, from the viewpoint of imparting extensibility when the cured coating film is formed. A polyol (with 3 hydroxyl groups) may be used in combination.

[Hydroxy group-containing (meth) acrylate (a3)]
Examples of the hydroxyl group-containing (meth) acrylate (a3) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. , 6-Hydroxyhexyl (meth) acrylate and other alkyl groups having 1 to 16 (preferably 1 to 12) carbon atoms, hydroxyalkyl (meth) acrylate, 2-hydroxyethylacryloyl phosphate, 2- (meth) acryloyloxy. Ethyl-2-hydroxypropylphthalate, caprolactone-modified 2-hydroxyethyl (meth) acrylate, dipropylene glycol (meth) acrylate, fatty acid-modified-glycidyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) Compounds having one (meth) acryloyl group such as acrylate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate; glycerindi (meth) acrylate, 2-hydroxy-3-acryloyl-oxypropyl methacrylate. Compounds having two (meth) acryloyl groups such as; pentaerythritol tri (meth) acrylate, caprolactone-modified pentaerythritol tri (meth) acrylate, ethylene oxide-modified pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate. , Caprolactone-modified dipentaerythritol penta (meth) acrylate, ethylene oxide-modified dipentaerythritol penta (meth) acrylate, succinic acid-modified pentaerythritol tri (meth) acrylate, and other compounds having three or more (meth) acryloyl groups. Be done.
These may be used individually by 1 type, or may be used in combination of 2 or more type.

Among these, a hydroxyl group-containing (meth) acrylate having one (meth) acryloyl group in the molecule is preferable because it can impart an appropriate crosslinked structure to the cured coating film and impart extensibility, and is particularly preferable. , Hydroxyalkyl (meth) acrylates, more preferably 2-hydroxyethyl (meth) acrylates, 2-hydroxypropyl (meth) acrylates, 2-hydroxybutyl (meth) acrylates, 4-hydroxybutyl (meth) acrylates, 6 -Hydroxyhexyl (meth) acrylate, caprolactone-modified 2-hydroxyethyl (meth) acrylate, particularly preferably 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) in terms of excellent reactivity and versatility. Acrylate, 4-hydroxybutyl (meth) acrylate, caprolactone-modified 2-hydroxyethyl (meth) acrylate.

[Preparation of urethane (meth) acrylate (A)]
The urethane (meth) acrylate (A) used in the present invention is, for example, the alicyclic structure-containing polyvalent isocyanate (a1), low molecular weight polyol (a2-1), high molecular weight polyester-based polyol (a2-2), hydroxyl group. It can be produced by charging the contained (meth) acrylate (a3) into a reactor in a batch or separately and reacting them, but the low molecular weight polyol (a2-1) and the high molecular weight polyester-based polyol (a2-2) can be produced. By reacting the reaction product obtained by previously reacting with the alicyclic structure-containing polyvalent isocyanate (a1) with the hydroxyl group-containing (meth) acrylate (a3), the stability of the reaction and the reduction of by-products can be reduced. It is useful in terms of such things.
In particular, the alicyclic structure-containing polyvalent isocyanate (a1), low molecular weight polyol (a2-1), and high molecular weight polyester-based polyol (a2-2) are reacted in the presence of the ethylenically unsaturated monomer (D) described later. After the reaction, the reaction product is reacted with a hydroxyl group-containing (meth) acrylate (a3) to produce the desired urethane (meth) acrylate (A). Meta) acrylate (A) can be produced.

Then, in order to obtain the urethane (meth) acrylate (A) in good yield, an alicyclic structure-containing polyhydric isocyanate (a1), a low molecular weight polyol (a2-1), a high molecular weight polyester-based polyol (a2-2), and a hydroxyl group are used. The molar ratio of the contained (meth) acrylate (a3) is preferably as follows.

A known reaction means can be used for the reaction of the alicyclic structure-containing polyvalent isocyanate (a1), the low molecular weight polyol (a2-1), and the high molecular weight polyester-based polyol (a2-2). At that time, for example, the isocyanate group in the alicyclic structure-containing polyvalent isocyanate (a1), the hydroxyl group in the polyol (the hydroxyl group in the low molecular weight polyol (a2-1), and the hydroxyl group in the high molecular weight polyester-based polyol (a2-2)). Isocyanate group: hydroxyl group = 2: 1 to 15:14 in terms of molar ratio), a terminal isocyanate group-containing urethane (meth) acrylate in which an isocyanate group remains can be obtained. Then, an addition reaction with the hydroxyl group-containing (meth) acrylate (a3) is possible with respect to the terminal isocyanate group.

A reaction product obtained by preliminarily reacting the alicyclic structure-containing polyvalent isocyanate (a1), a low molecular weight polyol (a2-1), and a high molecular weight polyester-based polyol (a2-2), and a hydroxyl group-containing (meth). ) A known reaction means can also be used for the addition reaction with the acrylate (a3).

The reaction molar ratio of the reaction product to the hydroxyl group-containing (meth) acrylate (a3) is, for example, that the alicyclic structure-containing polyvalent isocyanate (a1) has two isocyanate groups and the hydroxyl group-containing (meth) acrylate (a3). When there is one hydroxyl group, the reaction product: hydroxyl group-containing (meth) acrylate (a3) is about 1: 2, and the alicyclic structure-containing polyvalent isocyanate (a1) has three isocyanate groups and hydroxyl groups. When the contained (meth) acrylate (a3) has one hydroxyl group, the reaction product: the hydroxyl group-containing (meth) acrylate (a3) is about 1: 3.

In the addition reaction between this reaction product and the hydroxyl group-containing (meth) acrylate (a3), urethane (meth) is terminated when the residual isocyanate group content of the reaction system becomes 0.3% by weight or less. ) Acrylate (A) is obtained.

Regarding the reaction conditions, for example, the reaction temperature is preferably set in the range of about 30 to 80 ° C. in order to obtain the urethane (meth) acrylate (A) in good yield, but the reaction heat can be controlled. Therefore, it is appropriate to carry out the reaction at 60 to 70 ° C., and the reaction time is usually 2 to 10 hours, preferably 3 to 8 hours.

The reaction between the alicyclic structure-containing polyvalent isocyanate (a1), the low molecular weight polyol (a2-1), and the high molecular weight polyester-based polyol (a2-2), and the reaction product thereof and the hydroxyl group-containing (meth) acrylate (meth). In the reaction with a3), it is also preferable to use a catalyst for the purpose of accelerating the reaction, and examples of the catalyst include dibutyltin dilaurate, dibutyltin dilaurate, trimethyltin hydroxide, tetra-n-butyltin, and bis. Organic metal compounds such as acetylacetonate zinc, zirconite tris (acetylacetonate) ethylacetacetate, zirconite tetraacetylacetonate, tin octatenate, zinc hexanoate, zinc octatenate, zinc stearate, zirconium 2-ethylhexanoate, Metal salts such as cobalt naphthenate, fistin chloride, ditin chloride, potassium acetate, triethylamine, triethylenediamine, benzyldiethylamine, 1,4-diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5 , 4,0] -7-Undecene, N, N, N', N'-tetramethyl-1,3-butanediamine, N-methylmorpholin, N-ethylmorpholin and other amine-based catalysts, bismuth nitrate, bromide In addition to bismuth, bismuth iodide, bismuth sulfide, etc., organic bismuth compounds such as dibutyl bismuth dilaurate and dioctyl bismuth dilaurate, 2-ethylhexanoic acid bismuth salt, naphthenic acid bismuth salt, isodecanic acid bismuth salt, neodecanoic acid bismuth salt, lauryl Organic acid bismuth such as acid bismuth salt, maleic acid bismuth salt, stearate bismuth salt, oleic acid bismuth salt, linoleic acid bismuth salt, acetate bismuth salt, bismuth ribisneodecanoate, disalicylic acid bismuth salt, di-eclipse acid bismuth salt. Examples thereof include bismuth-based catalysts such as salts, and among them, dibutyltin dilaurate and 1,8-diazabicyclo [5,4,0] -7-undecene are preferable. These may be used alone or in combination of two or more.

The blending amount of the catalyst is usually 0.01 to 1,000 ppm, preferably 0.1 to 500 ppm, and particularly preferably 1 to 300 ppm with respect to the total of the reaction components.

Further, in the above reaction, it is preferable to further use a polymerization inhibitor. As the polymerization inhibitor, known general substances used as polymerization inhibitors can be used, and for example, p-benzoquinone, naphthoquinone, toluquinone, 2,5-diphenyl-p-benzoquinone, hydroquinone, 2, Examples thereof include quinones such as 5-di-t-butylhydroquinone, methylhydroquinone and mono-t-butylhydroquinone, aromatics such as 4-methoxyphenol and dibutylhydroxytoluene, and pt-butylcatechol. Of these, aromatics are preferable, and 4-methoxyphenol and dibutylhydroxytoluene are particularly preferable.

It is preferable not to use an organic solvent in the above reaction, but it can also be used if necessary. Examples of the organic solvent include ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone, cellosolves such as ethyl cellosolve, aromatics such as toluene and xylene, and acetate esters such as methyl acetate, ethyl acetate and butyl acetate. Kind etc. can be mentioned. These above-mentioned organic solvents may be used alone or in combination of two or more. When an organic solvent is used, it is preferable that the active energy ray-curable resin composition of the present invention is substantially solvent-free. Therefore, the organic solvent is dried and removed through a drying step at the time of reaction generation. It is preferable to do so. Since it is necessary that the various monomer components used in the above reaction do not volatilize during the above-mentioned dry removal, it is preferable to use an organic solvent having a low boiling point. In the present invention, the low boiling point specifically means 60 ° C. or lower. When an organic solvent is used in the reaction generation, a trace amount of the solvent component derived from the organic solvent may remain in the active energy ray-curable resin composition, but in the present invention, the organic solvent is substantially used. Does not contain (solvent-free). That is, the fact that the organic solvent is substantially not contained means that the organic solvent is not positively blended, and the case where the trace amount remains is excluded. And, "substantially free of organic solvent" means that the content of the organic solvent in the active energy ray-curable resin composition is usually 1% by weight or less, preferably 0.1% by weight. The lower limit is usually 0.0001% by weight.

The content of the ethylenically unsaturated group in the urethane (meth) acrylate (A) is preferably 1 to 10, more preferably 1 to 6, and particularly preferably 1 to 3.

The weight average molecular weight of the urethane (meth) acrylate (A) is preferably 1,000 to 50,000, more preferably 3,500 to 45,000, and particularly preferably 7,000 to 40,000. .. If the weight average molecular weight of the urethane (meth) acrylate (A) is too small, the concentration of ethylenically unsaturated groups in the cured coating film becomes relatively large, and the extensibility of the coating film can be obtained when the cured coating film is formed. If the weight average molecular weight of the urethane (meth) acrylate (A) is too large, the viscosity tends to be high and the reaction control tends to be difficult, and the concentration of ethylenically unsaturated groups in the cured coating film tends to be difficult. Since it becomes relatively small and the crosslink density becomes low, the extensibility of the cured coating film can be obtained, but the young ratio tends to be low.

The weight average molecular weight is a weight average molecular weight converted to a standard polystyrene molecular weight. A high-speed liquid chromatograph (“ACQUITY APC system” manufactured by Waters) has a column: ACQUITY APC XT 450, ACQUITY APC XT 200. Is measured by using one ACQUITY APC XT 45 in series, for a total of four ACQUITY APC XT 45.

<< Urethane (meth) acrylate (B) >>
The urethane (meth) acrylate (B) used in the present invention is a reaction generated by reacting with a polyvalent isocyanate (b1) containing an alicyclic structure, a polyol (b2), and a hydroxyl group-containing (meth) acrylate (b3). It is a thing. The polyol (b2) contains a low molecular weight polyol (b2-1) having a number average molecular weight of 300 or less and a high molecular weight polycarbonate-based polyol (b2-2) having a number average molecular weight of 500 to 20,000. That is, the urethane (meth) acrylate (B) used in the present invention is a structural unit derived from the alicyclic structure-containing polyvalent isocyanate (b1) and a structural unit derived from a low molecular weight polyol (b2-1) having a number average molecular weight of 300 or less. , A compound having a structural unit derived from a high molecular weight polycarbonate-based polyol (b2-2) having a number average molecular weight of 500 to 20,000 and a structural unit derived from a hydroxyl group-containing (meth) acrylate (b3). From the viewpoint of the action and effect of the present invention, 50% by weight or more, particularly 80% by weight or more of the total amount of the polyol (b2) is the low molecular weight polyol (b2-1) and the high molecular weight polycarbonate-based polyol (b2-2). ), And it is more preferable that all of the above-mentioned polyols (b2) are made of the above-mentioned low molecular weight polyol (b2-1) and the high-molecular-weight polycarbonate-based polyol (b2-2).

[Alicyclic structure-containing multivalent isocyanate (b1)]
As the alicyclic structure-containing multivalent isocyanate (b1), the same as the alicyclic structure-containing polyvalent isocyanate (a1) described above is used. The alicyclic structure-containing polyvalent isocyanate (a1) and (b1) may be the same alicyclic structure-containing polyvalent isocyanate, or different alicyclic structure-containing polyvalent isocyanates may be used.

[Polyol (b2)]
As the above-mentioned polyol (b2), as described above, a low molecular weight polyol (b2-1) having a number average molecular weight of 300 or less and a high molecular weight polycarbonate-based polyol (b2-2) having a number average molecular weight of 500 to 20,000. And are used in combination.

In particular, the ratio (b2-1 / b2-2) of the low molecular weight polyol (b2-1) to the high molecular weight polycarbonate-based polyol (b2-2) is 1/99 to 50/50 by weight. However, it is preferable because it is easy to impart a higher Young's modulus and a higher elongation, and the physical properties can be finely adjusted. From the same viewpoint, the above ratio (weight ratio) is more preferably (b2-1 / b2-2) = 1.5 / 98.5 to 49/51, and particularly preferably (b2-1 / b2-). 2) = 2/98 to 48/52.

Further, the low molecular weight polyol (b2-1) is a polyol having a number average molecular weight of 60 to 300, and the high molecular weight polycarbonate-based polyol (b2-2) is a polycarbonate-based polyol having a number average molecular weight of 500 to 20,000. It is preferable because it is easy to impart a higher young rate and a higher elongation, and the physical properties can be finely adjusted. From the same viewpoint, the low molecular weight polyol (b2-1) is a polyol having a number average molecular weight of 70 to 250, and the high molecular weight polycarbonate-based polyol (b2-2) is a polycarbonate having a number average molecular weight of 600 to 15,000. The system-based polyol is more preferable, and particularly preferably, the low molecular weight polyol (b2-1) is a polyol having a number average molecular weight of 80 to 200, and the high-molecular-weight polycarbonate-based polyol (b2-2) is a number. This is the case of a polycarbonate-based polyol having an average molecular weight of 700 to 10,000.

Then, as the low molecular weight polyol (b2-1), the same one as the low molecular weight polyol (a2-1) described above is used. The low molecular weight polyol (a2-1) and (b2-1) may use the same low molecular weight polyol or different low molecular weight polyols.

Examples of the high molecular weight polycarbonate-based polyol (b2-2) include a reaction product of a polyhydric alcohol and phosgene; a ring-opening polymer of a cyclic carbonate ester (alkylene carbonate, etc.).

Examples of the polyhydric alcohol include polyhydric alcohols exemplified in the description of the high molecular weight polyester-based polyol (a2-2), and examples of the alkylene carbonate include ethylene carbonate, trimethylene carbonate, and tetramethylene carbonate. Hexamethylene carbonate and the like can be mentioned.

The polycarbonate-based polyol may be a compound having a carbonate bond in the molecule and having a hydroxyl group at the end, and may have an ester bond together with the carbonate bond.

As the polyol (b2) as a whole, it is preferable to use a bifunctional (two hydroxyl groups) polyol, and further, a bifunctional polyol and a trifunctional polyol, from the viewpoint of imparting extensibility when the cured coating film is formed. A polyol (with 3 hydroxyl groups) may be used in combination.

[Hydroxy group-containing (meth) acrylate (b3)]
As the hydroxyl group-containing (meth) acrylate (b3), the same as the hydroxyl group-containing (meth) acrylate (a3) described above is used. The same hydroxyl group-containing (meth) acrylate may be used for the hydroxyl group-containing (meth) acrylate (a3) and (b3), or different hydroxyl group-containing (meth) acrylates may be used.

Among the hydroxyl group-containing (meth) acrylates (b3), the hydroxyl group-containing (meth) acrylate having one (meth) acryloyl group in the molecule imparts an appropriate crosslinked structure to the cured coating film and is elongated. It is preferable because it can impart properties, and particularly preferably hydroxyalkyl (meth) acrylate, and more preferably 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, or 2-hydroxybutyl (meth) acrylate. , 4-Hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, caprolactone-modified 2-hydroxyethyl (meth) acrylate, particularly preferably 2-hydroxyethyl (meth) acrylate in terms of excellent reactivity and versatility. Meta) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, caprolactone-modified 2-hydroxyethyl (meth) acrylate.

[Preparation of urethane (meth) acrylate (B)]
The urethane (meth) acrylate (B) used in the present invention is the urethane (meth) described above, except that the high molecular weight polycarbonate-based polyol (b2-2) is used instead of the high-molecular-weight polyester-based polyol (a2-2). ) Prepared according to the method for producing acrylate (A).

The content of the ethylenically unsaturated group in the urethane (meth) acrylate (B) is preferably 1 to 10, more preferably 1 to 6, and particularly preferably 1 to 3.

The weight average molecular weight of the urethane (meth) acrylate (B) is preferably 1,000 to 50,000, more preferably 3,500 to 45,000, and particularly preferably 7,000 to 40,000. .. If the weight average molecular weight of the urethane (meth) acrylate (B) is too small, the concentration of ethylenically unsaturated groups in the cured coating film becomes relatively large, and the extensibility of the coating film can be obtained when the cured coating film is formed. If the weight average molecular weight of the urethane (meth) acrylate (B) is too large, the viscosity tends to be high and the reaction control tends to be difficult, and the concentration of ethylenically unsaturated groups in the cured coating film tends to be difficult. Since it becomes relatively small and the crosslink density becomes low, the extensibility of the cured coating film can be obtained, but the young ratio tends to be low.

<< Urethane (meth) acrylate (C) >>
The urethane (meth) acrylate (C) used in the present invention is a reaction product obtained by reacting with a polyisocyanate (c1) and a hydroxyl group-containing (meth) acrylate (c2). That is, the urethane (meth) acrylate (C) used in the present invention is a compound having a structural unit derived from polyisocyanate (c1) and a structural unit derived from hydroxyl group-containing (meth) acrylate (c2).

[Polyisocyanate (c1)]
Examples of the polyisocyanate (c1) include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylenedi isocyanate, and naphthalene diisocyanate; Alibo polyisocyanate such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, lysine triisocyanate; alicyclic structure such as hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane. Examples thereof include polyisocyanates contained; or trimeric or multimer compounds of these polyisocyanates, allophanate-type polyisocyanates, bullet-type polyisocyanates, water-dispersed polyisocyanates, and the like.
These may be used individually by 1 type, or may be used in combination of 2 or more type.

Among these, aliphatic diisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate, hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, norbornene diisocyanate, and 1,3-bis (isosyanatomethyl) are low in yellowing. An alicyclic structure-containing diisocyanate such as cyclohexane is preferable, and isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, and hexamethylene diisocyanate are particularly preferable because they have a small curing shrinkage. , And more preferably, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, and hexamethylene diisocyanate are used because of their excellent reactivity and versatility.

[Hydroxy group-containing (meth) acrylate (c2)]
As the hydroxyl group-containing (meth) acrylate (c2), the same as the hydroxyl group-containing (meth) acrylate (a3) described above is used. The same hydroxyl group-containing (meth) acrylate may be used for the hydroxyl group-containing (meth) acrylate (a3) and (c2), or different hydroxyl group-containing (meth) acrylates may be used.

[Preparation of urethane (meth) acrylate (C)]
The urethane (meth) acrylate (C) used in the present invention can be produced, for example, by charging the polyisocyanate (c1) and the hydroxyl group-containing (meth) acrylate (c2) into a reactor and reacting them. The reaction temperature at the time of production and the catalyst are set according to the method for producing urethane (meth) acrylate (A) described above.

Then, in order to obtain the urethane (meth) acrylate (C) in good yield, the molar ratio of the polyisocyanate (c1) and the hydroxyl group-containing (meth) acrylate (c2) is (c1) :( c2) = 1: 2. It is preferable to mix them in a ratio of about.

The content of the ethylenically unsaturated group in the urethane (meth) acrylate (C) is preferably 2 to 10, and more preferably 1 to 6.

The weight average molecular weight of the urethane (meth) acrylate (C) is preferably 3,000 or less, more preferably 2,000 or less, and particularly preferably 1,500 or less. If the weight average molecular weight of the urethane (meth) acrylate (C) is too small, the concentration of ethylenically unsaturated groups in the cured coating film becomes relatively large, and the extensibility of the coating film can be obtained when the cured coating film is formed. If the weight average molecular weight of the urethane (meth) acrylate (C) is too large, the viscosity tends to be high and the reaction control tends to be difficult, and the concentration of ethylenically unsaturated groups in the cured coating film tends to be difficult. Since it becomes relatively small and the crosslink density becomes low, the extensibility of the cured coating film can be obtained, but the young ratio tends to be low.

<< Ethylene unsaturated monomer (D) >>
In addition to the urethane (meth) acrylates (A) to (C) described above, the resin composition of the present invention preferably further contains an ethylenically unsaturated monomer (D). In the present invention, the ethylenically unsaturated monomer (D) usually refers to a monomer having one ethylenically unsaturated group. The ethylenically unsaturated monomer (D) has a number average molecular weight of 1,000 or less. In the present invention, the ethylenically unsaturated monomer (D) preferably contains an alicyclic structure-containing (meth) acrylate (d1) in order to obtain desired flexibility and the like. Further, from the viewpoint of effectively obtaining flexibility and the like, the proportion of the alicyclic structure-containing (meth) acrylate (d1) in the ethylenically unsaturated monomer (D) is 40% by weight of the entire ethylenically unsaturated monomer. The above is preferable, and more preferably 60% by weight or more of the total ethylenically unsaturated monomer.

Further, in order to enhance the flexibility and realize high Young's modulus and high elongation, the alicyclic structure-containing (meth) acrylate (d1) and the heterocyclic structure-containing (meth) acrylate (d2) should be used in combination. Is preferable. In particular, from the viewpoint of enhancing flexibility and achieving high Young's modulus and high elongation, the alicyclic structure-containing (meth) acrylate (d1) and heterocyclic structure-containing (meth) in the ethylenically unsaturated monomer (D) are contained. The content ratio (d1 / d2) with the acrylate (d2) is preferably 99/1 to 1/99 in terms of weight ratio, and from the same viewpoint, the range of d1 / d2 = 95/5 to 5/90. Is more preferable, and the range of d1 / d2 = 90/10 to 10/90 is particularly preferable.

Further, the alicyclic structure-containing (meth) acrylate (d1) is more tough and flexible when it is a (meth) acrylate having a glass transition temperature of 100 ° C. or higher, preferably 100 to 180 ° C. when used as a homopolymer. A coating film can be obtained.

The glass transition temperature (Tg) when homopolymers of each monomer are used is usually measured by a differential scanning calorimeter (DSC), and is measured by a method compliant with JIS K 7121-1987 or JIS K 6240. can do.

Examples of the alicyclic structure-containing (meth) acrylate (d1) include dicyclopentanyl acrylate (Tg = 120 ° C.), dicyclopentanyl acrylate (Tg = 120 ° C.), and isobornyl methacrylate (Tg = 180 ° C.). ), 1-adamantyl acrylate (Tg = 153 ° C.), 1-adamantyl methacrylate (Tg = 250 ° C.) and the like. These may be used individually by 1 type, or may be used in combination of 2 or more type.
The temperature in () is the glass transition temperature (Tg) when homopolymers of each monomer are used.

Examples of the heterocyclic structure-containing (meth) acrylate (d2) include acryloyl morpholine (Tg = 145 ° C.), (meth) acryloylpyrrolidone, (meth) acryloylpiperidin, (meth) acryloylpyrrolidine, and (meth) acryloyl. Acryloyl and the like can be mentioned. These may be used individually by 1 type, or may be used in combination of 2 or more type.

In the present invention, for example, an aliphatic alkyl acrylate is used as the ethylenically unsaturated monomer (D) other than the alicyclic structure-containing (meth) acrylate (d1) and the heterocyclic structure-containing (meth) acrylate (d2). You can also.

The content of the ethylenically unsaturated monomer (D) is a two-component or two components selected from the three components of the specific urethane (meth) acrylate [(A) to (C), from the viewpoint of excellent flexibility. Three components] It is preferably 100 to 400 parts by weight, more preferably 110 to 380 parts by weight, particularly preferably 120 to 350 parts by weight, and further preferably 130 to 330 parts by weight with respect to 100 parts by weight.

The viscosity (25 ° C.; E-type viscometer) of the mixture of the specific urethane (meth) acrylate (A) and the ethylenically unsaturated monomer (D) is preferably 20,000 mPa · s or less, and particularly preferably 10. It is 000 mPa · s or less, more preferably 5,000 mPa · s or less, and particularly preferably 2,000 mPa · s or less. The lower limit is usually 10 mPa · s.

In the active energy ray-curable resin composition of the present invention, it is preferable to further contain a photopolymerization initiator (E) in order to impart curability.

The photopolymerization initiator (E) is not particularly limited as long as it generates radicals by the action of light, and is, for example, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one. , Benzyldimethylketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxy-cyclohexyl-phenyl-ketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-Hydroxy-2-methyl-1-propane-1-one, 2-methyl-2-morpholino (4-thiomethylphenyl) propane-1-one, 2-benzyl-2-dimethylamino-1- (4) -Acetophenones such as morpholinophenyl) butanone, 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin Benzoins such as isobutyl ether; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenylsulfide, 3,3', 4,4'-tetra (t-butylperoxy) Carbonyl) benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethanamineium bromide, (4-benzoyl) Phenylphenones such as trimethylammonium chloride; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino) -2-Hydroxy) -3,4-dimethyl-9H-thioxanthone-9-onemethochloride and other thioxanthones; 2,4,6-trimethylbenzoyl-diphenylphosphinoxide, bis (2,6-dimethoxybenzoyl)- Examples thereof include acylphosphon oxides such as 2,4,4-trimethyl-pentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphinoxide; and the like. In addition, these photopolymerization initiators (E) may be used individually by 1 type, or may be used in combination of 2 or more type.

Further, as an auxiliary agent for the photopolymerization initiator (E), triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Mihiler ketone), 4,4'-diethylaminobenzophenone, 2-dimethylaminoethyl benzoic acid , 4-Dimethylaminobenzoate ethyl, 4-dimethylaminobenzoic acid (n-butoxy) ethyl, 4-dimethylaminobenzoate isoamyl, 4-dimethylaminobenzoate 2-ethylhexyl, 2,4-diethylthioxanthone, 2 , 4-Diisopropylthioxanson, etc. can also be used in combination. These auxiliaries may be used alone or in combination of two or more.

Regarding the content of the photopolymerization initiator (E), 0. It is preferably 1 to 20 parts by weight, particularly preferably 0.5 to 10 parts by weight, and further preferably 1 to 7.5 parts by weight. If the content is too small, curing tends to be poor and it tends to be difficult to form a coating film, and if it is too large, it causes yellowing of the cured coating film and tends to cause a problem of coloring.

Further, the active energy ray-curable resin composition of the present invention includes the specific urethane (meth) acrylates (A) to (C), the specific ethylenically unsaturated monomer (D), and a photopolymerization initiator (E). ), Antioxidants, flame retardants, antistatic agents, fillers, leveling agents, stabilizers, reinforcing agents, matting agents and the like can also be blended. Further, as the cross-linking agent, a compound having an action of causing cross-linking by heat, specifically, an epoxy compound, an aziricin compound, a melamine compound, an isocyanate compound, a chelate compound and the like can also be used.

<< Active energy ray-curable resin composition >>
The active energy ray-curable resin composition of the present invention comprises the specific urethane (meth) acrylates (A) to (C), the specific ethylenically unsaturated monomer (D), and a photopolymerization initiator (E). Further, it can be produced by blending the above-mentioned various additives in a predetermined blending amount and mixing them.

The active energy ray-curable resin composition of the present invention does not substantially contain an organic solvent as well as water and an aqueous solvent, and usually contains the specific urethane (meth) acrylates (A) to (C), the above-mentioned. It is preferable that the specific ethylenically unsaturated monomer (D), the photopolymerization initiator (E), and other components appropriately blended as necessary are dissolved or uniformly dispersed. This active energy ray-curable resin composition can be prepared by heating and mixing each of the above-mentioned compounding components in a temperature range of normal temperature (25 ° C. ± 10 ° C.) or, in some cases, normal temperature to 60 ° C. More preferably, each component except the photopolymerization initiator (E) is premixed (0.5 to 30 hours) in advance at room temperature or in a heated state in the above temperature range, and then the photopolymerization initiator (E) is mixed. By doing so, the above-mentioned active energy ray-curable resin composition is prepared. The active energy ray-curable resin composition thus obtained is a solvent-free resin composition that does not substantially contain an organic solvent.

The viscosity of the active energy ray-curable resin composition thus obtained is preferably 100 to 20,000 mPa · s, more preferably 300 to 10,000 mPa · s at 25 ° C. It is preferably 500 to 5,000 mPa · s. If the viscosity is too low, the cured coating film tends to be inflexible and difficult to stretch, and if the viscosity is too high, it tends to be difficult to use as a coating agent or for sheet molding.
The viscosity is measured using an E-type viscometer.

《Coating agent, sheet》
The active energy ray-curable resin composition of the present invention is used, for example, as a coating agent.

Further, the active energy ray-curable resin composition is used as a coating agent, and is applied to a substrate to form a coating film, which is then irradiated with active energy rays to cure the coating film and peel it off. This makes it possible to produce a sheet.

In the present invention, the "sheet" conceptually includes a sheet and a film.

The base material to which the active energy ray-curable resin composition of the present invention is applied includes a polyolefin resin, a polyester resin, a polycarbonate resin, an acrylic resin, an acrylonitrile butadiene styrene copolymer (ABS), and a polystyrene. Metals (aluminum, copper, (Iron, SUS, zinc, magnesium, alloys thereof, etc.) and a base material having a primer layer on a base material such as glass can be mentioned.

Examples of the coating method of the active energy ray-curable resin composition of the present invention include wet coating methods such as spray, shower, dipping, roll, spin, screen printing, etc., usually at room temperature. It may be applied to the base material.

Active energy rays applied on the substrate Examples of the active energy rays used for curing the curable resin composition include far-ultraviolet rays, ultraviolet rays, near-ultraviolet rays, rays of infrared rays, X-rays, γ-rays and the like. In addition to the electromagnetic waves of the above, electron beams, proton rays, neutron rays, etc. can be used, but curing by ultraviolet irradiation is advantageous in terms of curing speed, availability of irradiation equipment, price, and the like. When the electron beam irradiation is performed, it can be cured without using the above-mentioned photopolymerization initiator (E).

When the active energy ray-curable resin composition of the present invention is cured by irradiation with ultraviolet rays, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, and a chemical that emit light in the wavelength range of 150 to 450 nm are emitted. A lamp, a non-electrode discharge lamp, an LED, or the like may be used to irradiate ultraviolet rays of 30 to 3,000 mJ / cm ² (preferably 100 to 1,500 mJ / cm ² ).
After irradiation with ultraviolet rays, heating can be performed as necessary to complete the curing. Examples of the heating conditions at that time include a temperature of 120 to 200 ° C. and the like.

The coating film thickness (thickness after curing) is usually 3 to 1,000 μm in consideration of light transmission so that the photopolymerization initiator (E) reacts uniformly as an ultraviolet curable coating film. It is often, preferably 5 to 500 μm, and particularly preferably 10 to 200 μm.

When a coating film is formed using the active energy ray-curable resin composition and then cured, if an organic solvent remains in the resin composition, it is preferable to dry and remove the organic solvent. The drying conditions are preferably a temperature of 40 to 120 ° C. and an hour of 1 to 20 minutes, and more preferably a temperature of 50 to 100 ° C. and an hour of 2 to 10 minutes.

Depending on its properties, the active energy ray-curable resin composition of the present invention may be, for example, a coating agent for smartphones, a coating agent for displays, a coating agent for touch panels, an outer coating material for optical fibers or flexible tubular materials, clothing, etc. It can be used as a material for forming an article to be attached to, a medical sheet material, a tube forming material, and the like.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.
In the example, "part" and "%" mean the weight standard.
Further, the weight average molecular weight, the number average molecular weight and the viscosity were measured according to the above-mentioned methods.

First, prior to the examples, urethane acrylates (A-1, B-1, C-1, X-1) were prepared as follows.

[Preparation of urethane acrylate (A-1)]
In a four-necked flask equipped with a thermometer, agitator, a water-cooled condenser, and a nitrogen gas inlet, 1,3-bis (isocyanatomethyl) cyclohexane (a1) 25.0 g (0.13 mol), neopentyl glycol (0.13 mol). a2-1) (Molecular weight: 104) 3.4 g (0.03 mol), bifunctional polyester polyol (a2-2) (hydroxyl value 63 mgKOH / g, number average molecular weight (Mn): 1,781) 114.1 g (0.06 mol), 0.12 g of dibutyl hydroxytoluene as a polymerization inhibitor and 0.03 g of dibutyltin dilaurate as a reaction catalyst were charged and reacted at 60 ° C. for 2 hours. Then, 7.6 g (0.065 mol) of 2-hydroxyethyl acrylate (a3) was charged into this system and reacted at 60 ° C. for 3 hours, and the reaction was terminated when the residual isocyanate group became 0.3%. By doing so, urethane acrylate (A-1) (weight average molecular weight (Mw): 18,000) was obtained.

[Preparation of urethane acrylate (B-1)]
In a four-necked flask equipped with a thermometer, agitator, a water-cooled condenser, and a nitrogen gas inlet, 1,3-bis (isocyanatomethyl) cyclohexane (b1) 68.9 g (0.35 mol), neopentyl glycol (0.35 mol) b2-1) (Molecular weight: 104) 27.7 g (0.27 mol), bifunctional polycarbonate polyol (b2-2) (hydroxyl value 143 mgKOH / g, number average molecular weight (Mn): 783) 46.3 g (0) .06 mol), 0.12 g of dibutyl hydroxytoluene as a polymerization inhibitor and 0.03 g of dibutyltin dilaurate as a reaction catalyst were charged and reacted at 60 ° C. for 2 hours. Then, 7.0 g (0.06 mol) of 2-hydroxyethyl acrylate (b3) was charged into this system and reacted at 60 ° C. for 3 hours, and the reaction was terminated when the residual isocyanate group became 0.3%. By doing so, urethane acrylate (B-1) (weight average molecular weight (Mw): 17,000) was obtained.

[Preparation of urethane acrylate (C-1)]
1,3-Bis (isocyanatomethyl) cyclohexane (c1) 63.2 g (0.33 mol), 2-hydroxypropyl in a four-necked flask equipped with a thermometer, agitator, water-cooled condenser, and nitrogen gas inlet. Urethane acrylate (C-1) was charged with 86.8 g (0.67 mol) of acrylate (c2), reacted at 60 ° C. for 3 hours, and the reaction was terminated when the residual isocyanate group became 0.3%. ) (Weight average molecular weight (Mw): 670) was obtained.

[Preparation of urethane acrylate (X-1)]
Isophoron diisocyanate 25.3 g (0.11 mol), polytetramethylene ether glycol (hydroxyl value 58 mgKOH / g, number average molecular weight) in a four-necked flask equipped with a thermometer, agitator, water-cooled condenser, and nitrogen gas inlet. Mn): 1,934) 111.1 g (0.056 mol), dibutyl hydroxytoluene 0.12 g as a polymerization inhibitor, and dibutyl tin dilaurate 0.03 g as a reaction catalyst were charged and reacted at 60 ° C. for 2 hours. Then, 3.0 g (0.025 mol) of 2-hydroxyethyl acrylate was charged into this system and reacted at 60 ° C. for 3 hours, and the reaction was terminated when the residual isocyanate group became 0.3%. , Urethane acrylate (X-1) (weight average molecular weight (Mw): 13,000) was obtained.

[Example 1]
Dicyclopentanyl acrylate (d1-1) (Tg = 120 ° C.) 50%, acryloylmorpholin as an ethylenically unsaturated monomer with respect to 40% of urethane acrylate (A-1) and 3% of urethane acrylate (C-1). (D2-1) (Tg = 145 ° C.) 5% and normal octyl acrylate (Tg = −65 ° C.) (d3) 2% were mixed and diluted.
For 100 parts of the solution (viscosity (25 ° C.): 4,300 mPa · s) thus obtained, a photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone (IGMresins), “Omnirad 184” ”)) (E-1) An active energy ray-curable resin composition was prepared by blending 4 parts.

[Example 2]
Dicyclopentanyl acrylate (d1-1) (Tg = 120 ° C.) 40% and acryloyl as ethylenically unsaturated monomers with respect to 30% urethane acrylate (A-1) and 10% urethane acrylate (B-1). 20% of morpholine (d2-1) (Tg = 145 ° C.) was mixed and diluted.
For 100 parts of the solution (viscosity (25 ° C.): 7,100 mPa · s) thus obtained, a photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone (IGMresins), “Omnirad 184” ”)) (E-1) An active energy ray-curable resin composition was prepared by blending 4 parts.

[Comparative Example 1]
Dicyclopentanyl acrylate (d1-1) (Tg = 120 ° C.) 40% and acryloyl as ethylenically unsaturated monomers with respect to 30% urethane acrylate (A-1) and 10% urethane acrylate (X-1). 20% of morpholine (d2-1) (Tg = 145 ° C.) was mixed and diluted. However, no other evaluation was performed because of poor compatibility and cloudiness.

Using the active energy ray-curable resin composition thus obtained, a measurement sample was prepared as follows, and the Young's modulus, elongation, transparency, and flexibility were described below for the sample. I evaluated it as a street. The results are shown in Table 1 below. In Table 1 below, urethane acrylates (A-1, B-1, C-1, X-1) and ethylenically unsaturated monomers (d1-1), which are constituents of the active energy ray-curable resin composition, are shown. , D2-1 and d3), the ratio of urethane acrylate (%) and the ratio of ethylenically unsaturated monomer (%) to the total content are also shown.

[Preparation of samples for measuring Young's modulus, elongation, transparency, and flexibility]
The active energy ray-curable resin composition is applied to a releasable polyethylene terephthalate (PET) film (thickness 100 μm) with an applicator, and using one high-pressure mercury lamp (80 W), the height is 3.4 m / min from a height of 18 cm. Two passes of ultraviolet irradiation (cumulative irradiation amount 800 mJ / cm ² ) were carried out at the same conveyor speed to obtain a cured coating film (thickness: 100 μm). Then, this cured coating film was punched out with a dumbbell to prepare a strip-shaped sample having a width of 15 mm and a length of 75 mm, and then the cured coating film was peeled off from the PET film to prepare a sample for measurement.

<Young's modulus>
A tensile test of a sample was carried out in accordance with JIS K 7127 using a tensile tester "AG-X" (manufactured by Shimadzu Corporation) at a temperature of 23 ° C. and a humidity of 50%. The tensile speed was 10 mm / min, and Young's modulus was measured from the inclination to the yield point and evaluated according to the following criteria.
◎ ・ ・ ・ 400 (N / mm ² ) or more.
○ ・ ・ ・ 200 (N / mm ² ) or more and less than 400 (N / mm ² ).
×: Less than 200 (N / mm ² ).

<Elongation>
A tensile test of a sample was carried out in accordance with JIS K 7127 using a tensile tester "AG-X" (manufactured by Shimadzu Corporation) at a temperature of 23 ° C. and a humidity of 50%. The tensile speed was 10 mm / min, and the elongation at the break point of the coating film was measured and evaluated according to the following criteria.
◎ ・ ・ ・ 300% or more.
○ ・ ・ ・ 200% or more and less than 300%.
× ・ ・ ・ Less than 200%.

<Transparency>
The sample was visually observed and evaluated according to the following criteria.
○ ・ ・ ・ It was transparent and no cloudiness was observed.
×: White turbidity was observed.

<Flexibility>
The obtained sample was repeatedly bent by hand and evaluated according to the following criteria.
◯ ... It did not break even if it was bent 100 times.
X ... Broken less than 100 times.

<Comprehensive judgment>
Based on each of the above measurement evaluations, a comprehensive judgment evaluation was performed according to the following criteria.
◎ ・ ・ ・ There was at least one evaluation of “◎”, and the other evaluations were “○”.
○ ・ ・ ・ Evaluation of “○” was obtained in all evaluations.
× ・ ・ ・ There was at least one evaluation of “×”.

From the above results, it can be seen that in all the examples, both Young's modulus and elongation are high, transparency is obtained, and flexibility is also excellent.

On the other hand, Comparative Example 1 also contains two types of urethane acrylates as in the examples, but one corresponding to the specific urethane (meth) acrylates (A) to (C) defined in the present invention is one. Only the type (A-1 only) was included, resulting in inferior transparency (white turbidity was observed).

INDUSTRIAL APPLICABILITY The present invention has high transparency, good elongation characteristics, high Young's modulus, high strength, and active energy ray curability capable of forming a coating film having excellent flexibility when used as a cured coating film. It is a resin composition, and further provides a coating agent and a sheet made by using the resin composition. Therefore, for example, a coating agent for smartphones, a coating agent for displays, a coating agent for touch panels, an outer coating material for optical fibers and flexible tubular objects, a material for forming articles to be attached to clothing, medical sheet materials, and tubes. Very useful for forming materials and the like. Further, since the coating film and the like have high transparency, little deterioration in physical properties at high temperature, and excellent chemical resistance, they can be used for various purposes utilizing these characteristics.

Claims (9)

An active energy ray-curable resin composition containing a urethane (meth) acrylate corresponding to two or three components selected from the following three components (A) to (C), at least the following (A) and ( An active energy ray-curable resin composition comprising a component (B) and further containing the following component (D) .
(A) Urethane (meth) acrylate which is a reaction product of alicyclic structure-containing polyvalent isocyanate (a1), polyol (a2), and hydroxyl group-containing (meth) acrylate (a3), wherein the polyol (a2) is. A urethane (meth) acrylate containing a low molecular weight polyol (a2-1) having a number average molecular weight of 300 or less and a high molecular weight polyester-based polyol (a2-2) having a number average molecular weight of 500 to 20,000.
(B) A urethane (meth) acrylate which is a reaction product of a polyhydric isocyanate (b1) containing an alicyclic structure, a polyol (b2), and a hydroxyl group-containing (meth) acrylate (b3), wherein the polyol (b2) is a reaction product. It contains a low molecular weight polyol (b2-1) having a number average molecular weight of 300 or less and a high molecular weight polycarbonate-based polyol (b2-2) having a number average molecular weight of 500 to 20,000.
The low molecular weight polyol (b2-1) is at least one selected from the group consisting of fatty alcohols, alicyclic diols, bisphenols, and sugar alcohols .
The ratio (b2-1 / b2-2) of the low molecular weight polyol (b2-1) to the high molecular weight polycarbonate-based polyol (b2-2) is 1/99 to 50/50 by weight, that is, urethane ( Meta) acrylate.
(C) Urethane (meth) acrylate which is a reaction product of polyisocyanate (c1) and hydroxyl group-containing (meth) acrylate (c2).
(D) An ethylenically unsaturated monomer having a glass transition temperature of 100 ° C. or higher when used as a homopolymer. At least the ratio (a2-1 / a2-2) of the urethane (meth) acrylate (A) contained therein and the low molecular weight polyol (a2-1) to the high molecular weight polyester-based polyol (a2-2) is the weight ratio. The active energy ray-curable resin composition according to claim 1, wherein the composition is 1/99 to 50/50. A claim comprising at least the urethane (meth) acrylate (A), wherein the hydroxyl group-containing (meth) acrylate (a3) is a (meth) acrylate having one (meth) acryloyl group in the molecule. Item 3. The active energy ray-curable resin composition according to Item 1 or 2. A claim comprising at least the urethane (meth) acrylate (B), wherein the hydroxyl group-containing (meth) acrylate (b3) is a (meth) acrylate having one (meth) acryloyl group in the molecule. Item 3. The active energy ray-curable resin composition according to any one of Items 1 to 3. The ethylenically unsaturated monomer (D) is an ethylenically unsaturated monomer containing at least one selected from an alicyclic structure-containing (meth) acrylate (d1) and an acrylamide-based monomer (d2). The active energy ray-curable resin composition according to any one of claims 1 to 4 . The ethylenically unsaturated monomer (D) contains an alicyclic structure-containing (meth) acrylate (d1) and an acrylamide-based monomer (d2), and the content ratio (d1 / d2) thereof is 99/1 or more by weight ratio. The active energy ray-curable resin composition according to any one of claims 1 to 4, which is 1/99. A claim characterized in that the content ratio of the ethylenically unsaturated monomer (D) is 100 to 400 parts by weight with respect to 100 parts by weight of the total amount of the urethane (meth) acrylates (A) to (C). Item 2. The active energy ray-curable resin composition according to any one of Items 1 to 6 . A coating agent comprising the active energy ray-curable resin composition according to any one of claims 1 to 7 . A sheet comprising a cured body of the active energy ray-curable resin composition according to any one of claims 1 to 7 .