JP6578692B2 - Active energy ray-curable resin composition and coating agent using the same - Google Patents

Description

  The present invention relates to an active energy ray-curable resin composition and a coating agent using the same, and more particularly, has a high hardness and scratch resistance when a cured coating film is formed, and a coating film at the time of curing. The present invention relates to an active energy ray-curable resin composition capable of forming a coating film having low curling property and excellent crack resistance and flexibility, and a coating agent using the same.

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

  In addition, the hard coating agent is less likely to cause curling due to shrinkage of the cured coating film (low curling property), in order to improve processing suitability such as punching processing and to be used in a flexible display developed in recent years. It is demanded that cracks or the like hardly occur even when a plastic film having a coating film is bent (high flexibility).

  As an active energy ray-curable resin composition that meets such demands, for example, Patent Document 1 contains urethane (meth) acrylate, tripentaerythritol octa (meth) acrylate, and a polymerization initiator as essential components. An active energy ray-curable resin composition is disclosed, and when the resin composition is applied to a plastic film, a high hardness is obtained and a cured coating film having excellent flexibility is obtained. It is shown.

  Patent Document 2 discloses an active energy ray-curable hard coat comprising a urethanation reaction product of a specific isocyanurate compound and a specific polyfunctional acrylate compound, a specific polyfunctional acrylate, and a photopolymerization initiator. A resin composition is disclosed, and by curing the resin composition, a hard coat film having high surface hardness, excellent scratch resistance and crack resistance, low curl properties, and high transparency can be formed. It is shown.

  Further, Patent Document 3 is obtained by reacting an isocyanate trimer having an isocyanurate skeleton, a urethane (meth) acrylate oligomer obtained by reacting a hydroxyl group-containing (meth) acrylate, a polyisocyanate compound and a polymer polyol component. An active energy ray-curable resin composition comprising a urethane (meth) acrylate oligomer obtained by reacting a hydroxyl group-containing (meth) acrylate with an isocyanate-terminated prepolymer and a (meth) acrylate compound is disclosed, and this resin composition It has been shown that a top coat layer excellent in solvent resistance, stain resistance and abrasion resistance can be formed by curing.

JP 2013-23585 A JP 2008-248069 A JP 2005-133050 A

  However, the cured coating film disclosed in Patent Document 1 has a flexibility evaluation of 6 to 10 using a mandrel tester (see Table 1). In the case of a flexible display application or when a film is bent, it is required that the evaluation of bendability by a mandrel testing machine is 5 or less. Therefore, the cured coating film disclosed in Patent Document 1 has bendability. It is insufficient.

  Moreover, in the technique of patent document 2, it is evaluated that it is favorable if the total height of four sides of a 10 cm square hard coat film is less than 120 mm (see paragraph [0094]). The cured film thus obtained was insufficient as a low curl property.

  Furthermore, the technique of Patent Document 3 discloses solvent resistance, contamination resistance, and abrasion resistance, but does not consider processing suitability and flexibility at all.

  Therefore, in the present invention, under such a background, when a cured coating film is formed, the scratch resistance and flexibility are excellent in balance, and the curling property of the coating film during curing is low, resulting in hardness and crack resistance. Another object of the present invention is to provide an active energy ray-curable resin composition capable of forming a coating film that is also excellent, and a coating agent using the same.

  However, as a result of intensive studies in view of such circumstances, the present inventor has obtained a urethane (meth) acrylate compound (A) having no polyol component and a urethane (meth) acrylate compound (B) having a polyol component. In the composition to be contained, the urethane (meth) acrylate compound (A) has an isocyanurate skeleton, the ethylenically unsaturated group concentration is high, and the urethane (meth) acrylate compound (B) has an alicyclic structure. And the content of the urethane (meth) acrylate compound (A) is equal to or greater than the content of the urethane (meth) acrylate compound (B). As a result, the inventors have found that the above problems can be solved, and have completed the present invention.

That is, the gist of the present invention is as follows.
Urethane (meth) acrylate compound (A) obtained by reacting isocyanate compound (a1) and hydroxyl group-containing (meth) acrylate compound (a2), and isocyanate compound (b1), hydroxyl group-containing (meth) acrylate compound Urethane (meth) acrylate compound (B) obtained by reacting compound (b2) and polyol compound (b3)
An active energy ray-curable resin composition containing
The isocyanate compound (a1) is a compound having an isocyanurate skeleton, and the isocyanate compound (b1) is an alicyclic structure-containing isocyanate,
The ethylenically unsaturated group concentration of the urethane (meth) acrylate compound (A) is 3 mmol / g or more, and the ethylenically unsaturated group concentration of the urethane (meth) acrylate compound (B) is 1.5 mmol / g or more and 3 mmol. / G,
Active energy characterized in that the content ratio (weight ratio) [(A) / (B)] of the urethane (meth) acrylate compound (A) and the urethane (meth) acrylate compound (B) is 1 or more. The present invention relates to a linear curable resin composition.
Moreover, in this invention, the coating agent characterized by containing the said active energy ray curable resin composition is also provided.

Since the active energy ray-curable resin composition of the present invention contains a urethane (meth) acrylate compound (A) having a high ethylenically unsaturated group concentration, the coating composition has an excellent balance between scratch resistance and flexibility. A membrane can be obtained. In addition, since it contains a urethane (meth) acrylate compound (B) having a lower ethylenically unsaturated group concentration than the urethane (meth) acrylate compound (A), the coating film has excellent hardness and crack resistance. The curling property of the coating film during curing can be suppressed.
The coating agent containing the active energy ray-curable resin composition of the present invention is useful for applications in which a cured coating film requires flexibility and crack resistance, for example, a flexible display that requires excellent flexibility. It is particularly useful as a surface coating agent for optical members such as, and as a coating agent for punching or the like that requires a cured coating to have crack resistance.

The present invention will be described in detail below, but these show examples of desirable embodiments.
In the present specification, (meth) acryl means acryl or methacryl, (meth) acrylate means acrylate or methacrylate, and (meth) acryloyloxy means acryloyloxy or methacryloyloxy, respectively. The resin is a resin obtained by polymerizing a polymerization component containing one or more (meth) acrylate monomers.

  The active energy ray-curable resin composition of the present invention contains a urethane (meth) acrylate compound (A) and a urethane (meth) acrylate compound (B). Hereinafter, each component will be described.

[Urethane (meth) acrylate compound (A)]
The urethane (meth) acrylate compound (A) in the present invention is obtained by reacting an isocyanate compound (a1) and a hydroxyl group-containing (meth) acrylate compound (a2). The urethane (meth) acrylate compound (A) can be used alone or in combination of two or more.

  Isocyanate compound (a1) is a compound having an isocyanurate skeleton, for example, an isocyanate compound having an isocyanurate skeleton obtained by isocyanurating diisocyanate such as aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate. Is mentioned.

  Examples of the aromatic diisocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate; Examples of the diisocyanate include hexamethylene diisocyanate, pentamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and lysine triisocyanate; Examples of the alicyclic diisocyanate include hydrogenated diphenylmethane diisocyanate and hydrogenated. Xylylene diisocyanate, isophorone dii Cyanate, norbornene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane.

  Among these, an aliphatic diisocyanate is preferable in terms of excellent yellowing resistance, and further has an isocyanurate skeleton obtained by isocyanurating an aliphatic diisocyanate in terms of excellent balance between scratch resistance and flexibility of a cured coating film. Isocyanate compounds are preferred, and isocyanate compounds having an isocyanurate skeleton obtained by isocyanurating hexamethylene diisocyanate are particularly preferred.

  Examples of the hydroxyl group-containing (meth) acrylate compound (a2) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth). Acrylate, hydroxyalkyl (meth) acrylate such as 6-hydroxyhexyl (meth) acrylate, 2-hydroxyethylacryloyl phosphate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 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) (Meth) acrylate compounds containing one ethylenically unsaturated group such as acrylate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate; glycerin di (meth) acrylate, 2-hydroxy- (Meth) acrylate compounds containing two ethylenically unsaturated groups such as 3-acryloyl-oxypropyl methacrylate; 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 ( Data) containing an ethylenically unsaturated group such as acrylate three or more (meth) acrylate compound. The hydroxyl group-containing (meth) acrylate compound (a2) can be used alone or in combination of two or more.

  Among these, (meth) acrylate compounds containing three or more ethylenically unsaturated groups are preferable in that they are excellent in reactivity and versatility, and have a good balance between scratch resistance and flexibility of the cured coating film. Erythritol tri (meth) acrylate is particularly preferred.

  The urethane (meth) acrylate compound (A) used in the present invention adjusts the functional group molar ratio between the isocyanate group of the isocyanate compound (a1) and the hydroxyl group of the hydroxyl group-containing (meth) acrylate compound (a2). And it can obtain by making an isocyanate type compound (a1) and a hydroxyl-containing (meth) acrylate type compound (a2) react using catalysts, such as a dibutyltin dilaurate, as needed.

  Specifically, the reaction molar ratio between the isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2) is, for example, that the isocyanate compound (a1) has two isocyanate groups and the hydroxyl group-containing (meta ) When the acrylate compound (a2) has one hydroxyl group, the isocyanate compound (a1): hydroxyl group-containing (meth) acrylate compound (a2) is about 1: 2, and the isocyanate compound (a1) When there are three isocyanate groups and the hydroxyl group-containing (meth) acrylate compound (a2) has one hydroxyl group, the isocyanate compound (a1): hydroxyl group-containing (meth) acrylate compound (a2) is 1: 3. Degree.

  In the addition reaction between the isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2), the reaction is terminated when the residual isocyanate group content in the reaction system is 0.5% by weight or less. Thus, a urethane (meth) acrylate compound (A) is obtained.

  In the reaction between the isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2), it is also preferable to use a catalyst for the purpose of accelerating the reaction. Examples of the catalyst include dibutyltin dilaurate and dibutyl. Organometallic compounds such as tin diacetate, trimethyltin hydroxide, tetra-n-butyltin, zinc bisacetylacetonate, zirconium tris (acetylacetonate) ethylacetoacetate, zirconium tetraacetylacetonate, tin octenoate, hexanoic acid Zinc, zinc octenoate, zinc stearate, zirconium 2-ethylhexanoate, cobalt naphthenate, stannous chloride, stannic chloride, potassium acetate and other metal salts, triethylamine, triethylenediamine, benzyldiethylamine, 1,4 Diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5,4,0] undecene, N, N, N ′, N′-tetramethyl-1,3-butanediamine, N-methylmorpholine, N -In addition to amine catalysts such as ethylmorpholine, bismuth nitrate, bismuth bromide, bismuth iodide, bismuth sulfide, etc., organic bismuth compounds such as dibutyl bismuth dilaurate, dioctyl bismuth dilaurate, bismuth 2-ethylhexanoate, naphthenic acid Bismuth salt, bismuth isodecanoate, bismuth neodecanoate, bismuth laurate, bismuth maleate, bismuth stearate, bismuth oleate, bismuth linoleate, bismuth acetate, bismuth bisneodecanoate, di Bismuth salicylate, bismuth digallate, etc. Mentioned hexane bismuth salts bismuth catalysts such as are these, dibutyltin dilaurate, 1,8-diazabicyclo [5,4,0] undecene is preferred. These can be used alone or in combination of two or more.

  In the reaction between the isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2), an organic solvent having no functional group that reacts with the isocyanate group, for example, an ester such as ethyl acetate or butyl acetate. , Organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone, and aromatics such as toluene and xylene can be used.

Thus, the urethane (meth) acrylate compound (A) used in the present invention is obtained, and the concentration of the ethylenically unsaturated group (mmol / g) of the urethane (meth) acrylate compound (A) is 3 mmol / g or more. It is preferably 3 to 10 mmol / g, particularly preferably 4 to 9 mmol / g, more preferably 5 to 8 mmol / g, and particularly preferably 5 to 7 mmol / g.
When the ethylenically unsaturated group concentration (mmol / g) of the urethane (meth) acrylate compound (A) is too low, the hardness of the cured coating film tends to decrease and the scratch resistance tends to decrease.

In addition, the ethylenically unsaturated group density | concentration of a urethane (meth) acrylate type compound (A) can be calculated by following formula (1), for example.
[Formula (1)] Ethylenically unsaturated group concentration (mmol / g) of urethane (meth) acrylate compound (A) = ethylenically unsaturated group concentration (mmol / g) of hydroxyl group-containing (meth) acrylate compound (a2) g) × (weight of hydroxyl group-containing (meth) acrylate compound (a2) in urethane (meth) acrylate compound (A) / weight of urethane (meth) acrylate compound (A))

  Therefore, the ethylenically unsaturated group concentration of the urethane (meth) acrylate compound (A) can be adjusted by changing the weight ratio of the isocyanate compound (a1) and the hydroxyl group-containing (meth) acrylate compound (a2). For example, when the molar ratio of isocyanate and hydroxyl group is kept constant, if an isocyanate compound (a1) having a large molecular weight is used, the ethylenically unsaturated concentration of the urethane (meth) acrylate compound (A) obtained is If the isocyanate compound (a1) having a relatively low molecular weight is used, the ethylenically unsaturated group concentration of the urethane (meth) acrylate compound (A) to be obtained is relatively increased. Moreover, if the hydroxyl-containing (meth) acrylate compound (a2) having a high molecular weight and a high ethylenically unsaturated group concentration is used, the ethylenically unsaturated concentration of the resulting urethane (meth) acrylate compound (A) is increased, If the hydroxyl group-containing (meth) acrylate compound (a2) having a low molecular weight and a low ethylenically unsaturated group concentration is used, the ethylenically unsaturated concentration of the resulting urethane (meth) acrylate compound (A) is lowered.

As a weight average molecular weight of a urethane (meth) acrylate type compound (A), Preferably it is 2,000-100,000, Most preferably, it is 3,000-80,000, More preferably, it is 5,000-50,000. .
If the weight average molecular weight is too high, the viscosity tends to be high and the handling tends to be difficult. If the weight average molecular weight is too low, the balance between the flexibility and hardness of the resulting cured coating film tends to be lowered.

In addition, said weight average molecular weight is a weight average molecular weight by standard polystyrene molecular weight conversion, for example, to a high performance liquid chromatography (Nippon Waters, "Waters2695 (main body)" and "Waters2414 (detector)"), Column: ShodexGPCKF-806L (exclusion limit molecular weight: 2 × 10 ⁷ , separation range: 100-2 × 10 ⁷ , theoretical plate number: 10,000 plates / piece, filler material: styrene-divinylbenzene copolymer, filler particles It can be measured by using a series of three (diameter: 10 μm).

[Urethane (meth) acrylate compound (B)]
The urethane (meth) acrylate compound (B) in the present invention is obtained by reacting an isocyanate compound (b1), a hydroxyl group-containing (meth) acrylate compound (b2), and a polyol compound (b3). . The urethane (meth) acrylate compound (B) can be used alone or in combination of two or more.

  The isocyanate compound (b1) is an alicyclic structure-containing isocyanate such as isophorone diisocyanate, norbornene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, hydrogenated. And xylylene diisocyanate and hydrogenated diphenylmethane diisocyanate. The isocyanate compound (b1) can be used alone or in combination of two or more.

  Examples of the hydroxyl group-containing (meth) acrylate compound (b2) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth). Acrylate, hydroxyalkyl (meth) acrylates such as 6-hydroxyhexyl (meth) acrylate, 2-hydroxyethylacryloyl phosphate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, dipropylene glycol (meth) acrylate, Fatty acid-modified glycidyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxy Hydroxyl-containing (meth) acrylate compounds containing one ethylenically unsaturated group such as propyl (meth) acrylate; glycerin di (meth) acrylate, 2-hydroxy-3-acryloyl-oxypropyl methacrylate, pentaerythritol tri (meta ), Ethylenically unsaturated groups such as acrylate, pentaerythritol tetra (meth) acrylate, ethylene oxide modified pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, ethylene oxide modified dipentaerythritol penta (meth) acrylate And a hydroxyl group-containing (meth) acrylate compound containing two or more. The hydroxyl group-containing (meth) acrylate compound (b2) can be used alone or in combination of two or more.

  Among these, a hydroxyl group (meth) acrylate compound containing one ethylenically unsaturated group is preferable, and 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) are preferable in terms of reactivity and versatility. Acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate are particularly preferable, and 2-hydroxyethyl (meth) acrylate is more preferable.

  Examples of the polyol compound (b3) include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1, 4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, 1,9-nonanediol, 2,2-dimethylol Heptane, trimethylene glycol, 1,4-tetramethylene glycol, dipropylene glycol, 1,3-tetramethylenediol, 2-methyl-1,3-trimethylenediol, 2,4-diethyl-1,5-pentamethylene Diol, hydrogenated bisphenol A, hydroxyalkyl Bisphenol A, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, 2,2,4-trimethyl-1,3-pentanediol, N, N-bis- (2-hydroxyethyl) dimethylhydantoin, etc. Low molecular weight diols; high molecular weights such as polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols, (meth) acrylic polyols, polycaprolactone polyols, polysiloxane polyols, polyurethane polyols, etc. These polyols can be mentioned.

  Examples of the polyether polyol include oxyalkylene structure-containing polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, and polyhexamethylene glycol, and random or block copolymer of these polyalkylene glycols. Coalescence is mentioned.

  Among these, an oxyalkylene structure-containing polyether polyol is preferable, and the number of carbon atoms of the alkylene structure is preferably 2 to 6, particularly preferably 2 to 4, and more preferably 4.

Examples of the polyester-based polyol include a condensation polymer of a polyhydric alcohol and a polycarboxylic acid; a ring-opening polymer of a cyclic ester (lactone); a polyhydric alcohol, a polycarboxylic acid, and a cyclic ester. And reactants.
Examples of the polyhydric alcohol include the low molecular weight diols described above.
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 dodecanedioic acid; -Cycloaliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, paraphenylene dicarboxylic acid, trimellitic acid, and the like.
Examples of the cyclic ester include propiolactone, β-methyl-δ-valerolactone, and ε-caprolactone.

Examples of the polycarbonate polyol include a reaction product of a polyhydric alcohol and phosgene; a transesterification product of a carbonate ester and a polyhydric alcohol, and the like.
Examples of the polyhydric alcohol include the low molecular weight diol, and examples of the alkylene carbonate include ethylene carbonate, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, and the like. Examples include diphenyl carbonate.
The polycarbonate-based polyol may be a compound having a carbonate bond in the molecule and a terminal being a hydroxyl group, and may have an ester bond together with the carbonate bond.

  Examples of the polyolefin-based polyol include those having a saturated hydrocarbon skeleton having a homopolymer or copolymer such as ethylene, propylene and butene, and having a hydroxyl group at the molecular end.

Examples of the polybutadiene-based polyol include those having a butadiene copolymer as a hydrocarbon skeleton and having a hydroxyl group at the molecular end.
The polybutadiene-based polyol may be a hydrogenated polybutadiene-based polyol in which all or part of the ethylenically unsaturated groups contained in the structure is hydrogenated.

  Examples of the (meth) acrylic polyol include those having at least two hydroxyl groups in the molecule of the polymer or copolymer of the (meth) acrylic acid ester. , For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, (meth) acrylic acid Examples include 2-ethylhexyl, (meth) acrylic acid decyl, (meth) acrylic acid dodecyl, (meth) acrylic acid alkyl esters such as octadecyl (meth) acrylic acid, and the like.

  Examples of polycaprolactone-based polyols include ε-caprolactone adducts of polyhydric alcohols.

  Examples of the polysiloxane polyol include dimethyl polysiloxane polyol and methylphenyl polysiloxane polyol.

  Examples of the polyurethane polyol include a reaction product of a polyvalent isocyanate compound and a polyol compound.

Among these polyol compounds (b3), polyester polyols and / or polyether polyols are preferable because the resulting cured coating film is excellent in balance between scratch resistance and flexibility.
Further, it is preferable to use a polyol-based compound containing 3 or more hydroxyl groups from the viewpoint that the obtained cured coating film has a better balance between scratch resistance and flexibility, and further, a polyester-based polyol having 3 or more hydroxyl groups. It is particularly preferable to use

  The production method of the urethane (meth) acrylate compound (B) is usually a batch of the isocyanate compound (b1), the hydroxyl group-containing (meth) acrylate compound (b2), and the polyol compound (b3) in a reactor. The reaction may be carried out separately, but the reaction product obtained by reacting the polyol compound (b3) and the isocyanate compound (b1) in advance is reacted with the hydroxyl group-containing (meth) acrylate compound (b2). This is useful in terms of reaction stability and reduction of by-products.

  For the reaction of the polyol compound (b3) and the isocyanate compound (b1), known reaction means can be used. In that case, for example, the molar ratio of the isocyanate group in the isocyanate compound (b1) to the hydroxyl group in the polyol compound (b3) is usually 2n: 0.1 × (2n-2) to 2n: (2n-2). After obtaining a terminal isocyanate group-containing urethane (meth) acrylate compound in which the isocyanate group remains, by adding (n is an integer of 2 or more), addition with a hydroxyl group-containing (meth) acrylate compound (b2) Allow reaction.

  For the addition reaction of the reaction product obtained by reacting the polyol compound (b3) and the isocyanate compound (b1) in advance with the hydroxyl group-containing (meth) acrylate compound (b2), a known reaction means is used. Can be used.

The reaction molar ratio between the reaction product and the hydroxyl group-containing (meth) acrylate compound (b2) is, for example, that the isocyanate compound (b1) has two isocyanate groups and the hydroxyl group-containing (meth) acrylate compound (b2). When there is one hydroxyl group, the reaction product: hydroxyl group-containing (meth) acrylate compound (b2) is about 1: 2 to 1: 5, and the isocyanate compound (b1) has three isocyanate groups, When the hydroxyl group-containing (meth) acrylate compound (b2) has one hydroxyl group, the reaction product: hydroxyl group-containing (meth) acrylate compound (b2) is about 1: 3 to 1:10.
In the addition reaction between the reaction product and the hydroxyl group-containing (meth) acrylate compound (b2), the reaction is terminated when the residual isocyanate group content in the reaction system is 0.5% by weight or less. A (meth) acrylate compound (B) is obtained.

  In the reaction between the polyol compound (b3) and the isocyanate compound (b1) and the reaction product with the hydroxyl group-containing (meth) acrylate compound (b2), a catalyst is used for the purpose of promoting the reaction. Examples of such catalysts include dibutyltin dilaurate, dibutyltin diacetate, trimethyltin hydroxide, tetra-n-butyltin, bisacetylacetonate zinc, zirconium tris (acetylacetonate) ethylacetoacetate, zirconium. Organometallic compounds such as tetraacetylacetonate, tin octenoate, zinc hexanoate, zinc octenoate, zinc stearate, zirconium 2-ethylhexanoate, cobalt naphthenate, stannous chloride, stannic chloride, potassium acetate, etc. Metal salt of triethylami , Triethylenediamine, benzyldiethylamine, 1,4-diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5,4,0] undecene, N, N, N ′, N′-tetramethyl-1, In addition to amine catalysts such as 3-butanediamine, N-methylmorpholine, N-ethylmorpholine, bismuth nitrate, bismuth bromide, bismuth iodide, bismuth sulfide, etc., organic bismuth compounds such as dibutyl bismuth dilaurate, dioctyl bismuth dilaurate, Bismuth 2-ethylhexanoate, bismuth naphthenate, bismuth isodecanoate, bismuth neodecanoate, bismuth laurate, bismuth maleate, bismuth stearate, bismuth oleate, bismuth linoleate, acetic acid Bismuth salt, bismuth bis-neodecano Bismuth catalysts such as organic acid bismuth salts such as bismuth salts, bismuth disalicylate and digallic acid bismuth, among others, dibutyltin dilaurate and 1,8-diazabicyclo [5,4,0] undecene are preferred. It is. These may be used alone or in combination of two or more.

  In the reaction between the polyol compound (b3) and the isocyanate compound (b1), and further in the reaction between the reaction product and the hydroxyl group-containing (meth) acrylate compound (b2), a functional group that reacts with an isocyanate group. For example, organic solvents such as esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and aromatic solvents such as toluene and xylene can be used.

  Moreover, reaction temperature is 30-90 degreeC normally, Preferably it is 40-80 degreeC, and reaction time is 2 to 10 hours normally, Preferably it is 3 to 8 hours.

Thus, the urethane (meth) acrylate compound (B) used in the present invention is obtained. The concentration of ethylenically unsaturated groups (mmol / g) of the urethane (meth) acrylate compound (B) is 1.5 mmol / g. g or more and less than 3 mmol / g, preferably 1.5 ~2.9 m mol / g, particularly preferably 1.5 ~2.7mmol / g, more preferably 1.5～2.5Mmol / g.
When the ethylenically unsaturated group concentration (mmol / g) of the urethane (meth) acrylate compound (B) is too high, the flexibility of the resulting cured coating film tends to be lowered.

In addition, the ethylenically unsaturated group density | concentration of a urethane (meth) acrylate type compound (B) can be calculated by following formula (2), for example.
[Formula (2)] Ethylenically unsaturated group concentration (mmol / g) of urethane (meth) acrylate compound (B) = Ethylenically unsaturated group concentration (mmol / g) of hydroxyl group-containing (meth) acrylate compound (b2) g) × (weight of hydroxyl group-containing (meth) acrylate compound (b2) in urethane (meth) acrylate compound (B) / weight of urethane (meth) acrylate compound (B))

Therefore, the ethylenic unsaturation of the urethane (meth) acrylate compound (B) by changing the weight ratio of the isocyanate compound (b1), the hydroxyl group-containing (meth) acrylate compound (b2) and the polyol compound (b3). The group concentration can be adjusted. For example, when the molar ratio of isocyanate to hydroxyl group is constant, the urethane (meth) acrylate compound (B) obtained by using the isocyanate compound (b1) having a large molecular weight. If the isocyanate compound (b1) having a relatively low molecular weight and a low molecular weight is used, the ethylenically unsaturated group concentration of the resulting urethane (meth) acrylate compound (B) is relatively increased. . Moreover, if the hydroxyl group-containing (meth) acrylate compound (b2) having a high molecular weight and a high ethylenically unsaturated group concentration is used, the ethylenically unsaturated concentration of the resulting urethane (meth) acrylate compound (B) is increased, If the hydroxyl group-containing (meth) acrylate compound (b2) having a low molecular weight and a low ethylenically unsaturated group concentration is used, the ethylenically unsaturated concentration of the resulting urethane (meth) acrylate compound (B) is lowered.
Furthermore, if the polyol compound (b3) having a large molecular weight is used, the ethylenically unsaturated concentration of the resulting urethane (meth) acrylate compound (B) is lowered, and if the polyol compound (b3) having a small molecular weight is used. The ethylenically unsaturated concentration of the urethane (meth) acrylate compound (B) obtained increases.

The weight average molecular weight of the urethane (meth) acrylate compound (B) is preferably 1,000 to 100,000, particularly preferably 2,000 to 30,000, more preferably 2,500 to 10,000, It is preferably 3,000 to 5,000.
If the weight average molecular weight is too high, the viscosity tends to be high and handling tends to be difficult, and if the weight average molecular weight is too low, the flexibility of the resulting cured coating film tends to decrease.

  In addition, said weight average molecular weight is a weight average molecular weight by standard polystyrene molecular weight conversion, and can be measured by the method similar to the above.

[Active energy ray-curable resin composition]
The active energy ray-curable resin composition of the present invention contains a urethane (meth) acrylate compound (A) and a urethane (meth) acrylate compound (B), and includes a urethane (meth) acrylate compound (A) and The content ratio (weight ratio) [(A) / (B)] with the urethane (meth) acrylate compound (B) is 1 or more, preferably 1 to 30, particularly preferably 1.5 to 20, and still more preferably. Is 2-10.
If the content ratio (weight ratio) [(A) / (B)] of the urethane (meth) acrylate compound (A) and the urethane (meth) acrylate compound (B) is too small, the hardness of the resulting cured coating film And the scratch resistance tends to decrease.

  In the active energy ray-curable resin composition of the present invention, if necessary, a photopolymerization initiator, an ethylenically unsaturated monomer other than the urethane (meth) acrylate compounds (A) and (B), an acrylic resin, a surface Conditioners, leveling agents, polymerization inhibitors, etc. can be added. Furthermore, oil, antioxidants, flame retardants, antistatic agents, fillers, stabilizers, reinforcing agents, matting agents, abrasives, organic It is also possible to mix fine particles, inorganic particles, and the like.

  Examples of the photopolymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy- 2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) Acetophenones such as butanone, 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomers; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, etc. Benzoin Benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 2,4 , 6-trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethananium bromide, (4-benzoylbenzyl) trimethylammonium chloride, etc. Benzophenones; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy) -3 , 4-Di Thioxanthones such as til-9H-thioxanthone-9-one mesochloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphos And acylphosphine oxides such as fin oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; In addition, these photoinitiators can be used individually or can use 2 or more types together.

  Further, auxiliary agents for these photopolymerization initiators include triethanolamine, triisopropanolamine, 4,4′-dimethylaminobenzophenone (Michler ketone), 4,4′-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, 4- Ethyl dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone, 2,4- Diisopropylthioxanthone and the like can be used in combination. These auxiliaries can be used alone or in combination of two or more.

  In addition, the active energy ray-curable resin composition of the present invention preferably uses an organic solvent for dilution in order to adjust the viscosity at the time of coating, if necessary. Examples of the organic solvent include alcohols such as methanol, ethanol, propanol, n-butanol and i-butanol, ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone, cellosolves such as ethyl cellosolve, toluene and xylene. And the like, glycol ethers such as propylene glycol monomethyl ether, acetates such as methyl acetate, ethyl acetate and butyl acetate, and diacetone alcohol. These organic solvents may be used alone or in combination of two or more. When using 2 or more types together, it is preferable from the viewpoint of the coating film appearance to select and combine 2 or more types from glycol ethers, ketones and alcohols.

  In addition, in manufacturing the active energy ray-curable resin composition of the present invention, the urethane (meth) acrylate compound (A) and the urethane (meth) acrylate compound (B), and, if necessary, a method of mixing other components Is not particularly limited, and various methods can be employed.

The active energy ray-curable resin composition of the present invention is effectively used as a curable resin composition for forming a coating film, such as a top coat agent and an anchor coat agent for various substrates. The active energy ray-curable resin composition of the present invention has a coating film contractibility due to a three-dimensional network structure while maintaining a coating film stretch characteristic unique to a urethane structure when a cured coating film is formed. A coating film having shrinkage performance can be obtained. Therefore, a cured coating film having high practicality as a resilience against scratches can be formed, and it is particularly useful as a coating material, ink, coating agent, especially a coating agent for the outermost surface.
Hereinafter, the coating agent containing the active energy ray-curable resin composition of the present invention will be described.

〔Coating agent〕
The coating agent of the present invention can be cured by irradiating with active energy rays after being applied to the substrate (after further drying if a composition diluted with an organic solvent is applied). .

  Examples of the base material to which the coating agent of the present invention is applied include, for example, polyolefin resins, polyester resins, polycarbonate resins, acrylic resins acrylonitrile butadiene styrene copolymers (ABS), polystyrene resins, and the like. Metal (aluminum, copper, iron, SUS, etc.) such as plastic base materials such as molded products (films, sheets, cups, etc.), composite base materials thereof, or composite base materials of the above materials mixed with glass fibers or inorganic materials Zinc, magnesium, alloys thereof, and the like, including metal films such as a metal vapor deposition film), and substrates having a primer layer on a substrate such as glass.

  Examples of the coating method for the coating agent include wet coating methods such as spraying, showering, dipping, roll, spinning, screen printing, and ink jet printing. Usually, coating is performed on a substrate under normal temperature conditions. be able to.

  The coating agent of the present invention is preferably applied by diluting with the organic solvent so that the solid content concentration is usually 3 to 60% by weight, preferably 5 to 40% by weight.

  The drying conditions for dilution with the organic solvent are as follows: the temperature is usually 40 to 120 ° C., preferably 50 to 100 ° C., and the drying time is usually 1 to 20 minutes, preferably 2 to 10 minutes. That's fine.

  Examples of active energy rays used for curing the coating agent applied on the substrate include, for example, deep ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays and other electromagnetic waves, X-rays, γ rays and other electromagnetic waves, as well as electrons. Although radiation, proton beam, neutron beam and the like can be used, curing by ultraviolet irradiation is advantageous from the viewpoint of curing speed, availability of an irradiation apparatus, price, and the like. In addition, when performing electron beam irradiation, it can harden | cure even if it does not use a photoinitiator.

When curing by ultraviolet irradiation, using a high-pressure mercury lamp emitting ultra-high pressure mercury lamp, ultra-high pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, chemical lamp, electrodeless discharge lamp, LED, etc. Usually, an ultraviolet ray of 30 to 3000 mJ / cm ² (preferably 100 to 1500 mJ / cm ² ) can be irradiated.
After the ultraviolet irradiation, heating can be performed as necessary to complete the curing.

  The coating film thickness (film thickness after curing) is usually 2 to 1000 μm, preferably 3 in view of light transmission so that the photopolymerization initiator can react uniformly as an active energy ray-curable coating film. It is -500 micrometers, Most preferably, it is 3-100 micrometers.

  The coating agent containing the active energy ray-curable resin composition thus obtained can form a cured coating film having excellent flexibility and crack resistance, such as a flexible display that requires excellent flexibility. It is particularly useful as a surface coating agent for the optical member, and as a coating agent for punching or the like that requires a cured coating to have crack resistance.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded. In the examples, “parts” and “%” mean weight basis. The hydroxyl value, ethylenically unsaturated group concentration, and weight average molecular weight were measured according to the methods described above.

<Production Example 1: Urethane (meth) acrylate-based compound (A-1)>
29.3 g of hexamethylene diisocyanate trimer (isocyanate group content: 21.0%) having an isocyanurate skeleton was added to a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser and a nitrogen gas inlet. 0.05 mol), 70.7 g (0.15 mol) of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (hydroxyl value 120 mg KOH / g), 2,6-di-tert-butylcresol 0 as a polymerization inhibitor 0.06 g and 0.02 g of dibutyltin dilaurate as a reaction catalyst were reacted at 60 ° C., and the reaction was terminated when the residual isocyanate group became 0.3% or less, and the urethane (meth) acrylate compound (A-1 ) (Ethylenically unsaturated group concentration 6.0 mmol / g; weight average molecular weight) 10,500) and 70 g, to obtain a mixture of pentaerythritol tetraacrylate 30g.

<Production Example 2: Urethane (meth) acrylate-based compound (A′-1)>
In the production example of the urethane (meth) acrylate compound (A-1), except that 29.3 g (0.05 mol) of hexamethylene diisocyanate trimer was changed to 15.8 g (0.07 mol) of isophorone diisocyanate. Were reacted in the same manner, and urethane (meth) acrylate compound (A′-1) (ethylenically unsaturated group concentration 7.3 mmol / g; weight average molecular weight 1,500) 61.5 g, pentaerythritol tris A mixture of 6.7 g of acrylate and 31.8 g of pentaerythritol tetraacrylate was obtained.
The urethane (meth) acrylate compound (A′-1) is a urethane (meth) acrylate compound that does not have an isocyanurate skeleton.

<Production Example 3: Urethane (meth) acrylate compound (A′-2)>
In the production example of the urethane (meth) acrylate compound (A-1), 70.7 g (0.15 mol) of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (hydroxyl value 120 mg KOH / g) was converted into 4-hydroxybutyl. The reaction was carried out in the same manner except that the acrylate was changed to 22.1 g (0.15 mol), and the urethane (meth) acrylate compound (A′-2) (ethylenically unsaturated group concentration 2.9 mmol / g; weight average) The molecular weight was 3,000).
The urethane (meth) acrylate compound (A′-2) is a urethane (meth) acrylate compound having an ethylenically unsaturated group concentration of less than 3 mmol / g.
As for the ethylenically unsaturated group concentration, the ethylenically unsaturated group concentration of 4-hydroxybutyl acrylate is 6.8 mmol / g, which is calculated from the charged weight in the urethane (meth) acrylate compound (A′-2). Since 43% of 4-hydroxybutyl acrylate is contained, it is calculated as 6.8 × 0.43 = 2.9 mmol / g.

<Production Example 4: Urethane (meth) acrylate-based compound (B-1)>
In a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet, 37.5 g (0.17 mol) of isophorone diisocyanate, 25.5 g of polytetramethylene glycol diol (hydroxyl value 167 mg KOH / g; hydroxyl group) Molecular weight 672 calculated from the valence; 0.04 mol), polyester triol 13.4 g (hydroxyl value 262 mg KOH / g; molecular weight calculated from the hydroxyl value 642; 0.02 mol), and dibutyltin dilaurate 0.02 g as the reaction catalyst. Charged and reacted at 80 ° C. When the residual isocyanate group became 11% or less, 23.6 g (0.2 mol) of 2-hydroxyethyl acrylate and 0.04 g of methoxyphenol as a polymerization inhibitor were further added and reacted at 60 ° C. The reaction was terminated at a point of 0.3% or less, and urethane (meth) acrylate compound (B-1) (ethylenically unsaturated group concentration 2.0 mmol / g; weight average molecular weight 3,400) was obtained. Obtained.

<Production Example 5: Urethane (meth) acrylate compound (B-2)>
In a four-necked flask equipped with a thermometer, stirrer, water-cooled condenser, and nitrogen gas inlet, 39.9 g (0.18 mol) of isophorone diisocyanate, 38.5 g of polyester triol (hydroxyl value 262 mgKOH / g; calculated from hydroxyl value) Molecular weight 642; 0.06 mol), 0.02 g of dibutyltin dilaurate was charged as a reaction catalyst, and reacted at 80 ° C. When the residual isocyanate group became 9.6% or less, 21.6 g (0.18 mol) of 2-hydroxyethyl acrylate and 0.04 g of methoxyphenol as a polymerization inhibitor were further charged and reacted at 60 ° C. The reaction was terminated when the isocyanate group became 0.3% or less, and the urethane (meth) acrylate compound (B-2) (ethylenically unsaturated group concentration 1.8 mmol / g; weight average molecular weight was 2,100). )

<Production Example 6 :: Urethane (meth) acrylate compound (B-3)>
In a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas blowing port, 32.8 g (0.15 mol) of isophorone diisocyanate, 49.6 g of polytetramethylene glycol diol (hydroxyl value 167 mgKOH / g, hydroxyl group) Molecular weight 672 calculated from the valence; 0.07 mol), 0.02 g of dibutyltin dilaurate was charged as a reaction catalyst, and reacted at 80 ° C. When the residual isocyanate group became 7.5% or less, 17.6 g (0.15 mol) of 2-hydroxyethyl acrylate and 0.04 g of methoxyphenol as a polymerization inhibitor were further charged and reacted at 60 ° C. The reaction was terminated when the isocyanate group became 0.3% or less, and the urethane (meth) acrylate compound (B-3) (ethylenically unsaturated group concentration 1.5 mmol / g; weight average molecular weight was 2,200). )

<Production Example 7: Urethane (meth) acrylate compound (B′-1)>
In the production example of the urethane (meth) acrylate compound (B-1), 23.6 g (0.2 mol) of 2-hydroxyethyl acrylate was mixed with pentaerythritol triacrylate and pentaerythritol tetraacrylate (hydroxyl value 120 mgKOH / g). ) 95 g, except that the reaction was conducted in the same manner, urethane (meth) acrylate compound (B′-1) (ethylenically unsaturated group concentration 4.4 mmol / g; weight average molecular weight 3,500) 137 g And 34 g of pentaerythritol tetraacrylate were obtained.
The urethane (meth) acrylate type compound (B′-1) is a urethane (meth) acrylate compound having an ethylenically unsaturated group concentration of 3 mmol / g or more.

<Production Example 8: Urethane (meth) acrylate compound (B′-2)>
In the production example of the urethane (meth) acrylate compound (B-1), except that 37.5 g (0.17 mol) of isophorone diisocyanate was changed to 28.4 g (0.17 mol) of hexamethylene diisocyanate. The reaction was performed to obtain urethane (meth) acrylate compound (B′-2) (ethylenically unsaturated group concentration 2.2 mmol / g; weight average molecular weight 3,300).
This urethane (meth) acrylate compound (B′-2) is a urethane (meth) acrylate compound that does not contain an alicyclic structure.

<Example 1>
90 parts of the mixture of urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate obtained above, 10 parts of urethane (meth) acrylate compound (B-1), 1-hydroxy- as a photoinitiator 4 parts of cyclohexyl-phenyl-ketone (manufactured by BASF Japan Ltd .; “Irgacure 184”) and 100 parts of ethyl acetate as a diluent solvent were uniformly mixed to obtain an active energy ray-curable resin composition.

<Example 2>
70 parts of the mixture of urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate obtained above, 30 parts of urethane (meth) acrylate compound (B-1), 1-hydroxy- as a photoinitiator 4 parts of cyclohexyl-phenyl-ketone (manufactured by BASF Japan Ltd .; “Irgacure 184”) and 100 parts of ethyl acetate as a diluent solvent were uniformly mixed to obtain an active energy ray-curable resin composition.

<Example 3>
60 parts of a mixture of urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate obtained above, 40 parts of urethane (meth) acrylate compound (B-1), 1-hydroxy- as a photoinitiator 4 parts of cyclohexyl-phenyl-ketone (manufactured by BASF Japan Ltd .; “Irgacure 184”) and 100 parts of ethyl acetate as a diluent solvent were uniformly mixed to obtain an active energy ray-curable resin composition.

<Example 4>
70 parts of a mixture of urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate obtained above, 30 parts of urethane (meth) acrylate compound (B-2), 1-hydroxy- as a photoinitiator 4 parts of cyclohexyl-phenyl-ketone (manufactured by BASF Japan Ltd .; “Irgacure 184”) and 100 parts of ethyl acetate as a diluent solvent were uniformly mixed to obtain an active energy ray-curable resin composition.

<Example 5>
80 parts of the mixture of urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate obtained above, 20 parts of urethane (meth) acrylate compound (B-3), 1-hydroxy- as a photoinitiator 4 parts of cyclohexyl-phenyl-ketone (manufactured by BASF Japan Ltd .; “Irgacure 184”) and 100 parts of ethyl acetate as a diluent solvent were uniformly mixed to obtain an active energy ray-curable resin composition.

<Example 6>
70 parts of a mixture of urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate obtained above, 20 parts of urethane (meth) acrylate compound (B-2), urethane (meth) acrylate compound ( B-3) 10 parts, 1 part of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF Japan Co., Ltd .; “Irgacure 184”) as a photoinitiator, and 100 parts of ethyl acetate as a diluting solvent are mixed uniformly and activated. An energy ray curable resin composition was obtained.

<Comparative Example 1>
In Example 2, 70 parts of a mixture of urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate was mixed with urethane (meth) acrylate compound (A'-1), pentaerythritol triacrylate and pentaerythritol tetra. An active energy ray-curable resin composition was obtained in the same manner except that the mixture was changed to 70 parts of an acrylate mixture.

<Comparative Example 2>
In Example 2, 70 parts of a mixture of urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate was mixed with a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (DPHA / DPPA) (hydroxyl value 48 mgKOH). / G) An active energy ray-curable resin composition was obtained in the same manner except that the amount was changed to 70 parts.

<Comparative Example 3>
In Example 2, 30 parts of the urethane (meth) acrylate compound (B-1) was added to 30 parts of the mixture of the urethane (meth) acrylate compound (B′-1) and pentaerythritol tetraacrylate obtained above. An active energy ray-curable resin composition was obtained in the same manner except that it was changed.

<Comparative Example 4>
In Example 2, 70 parts of the mixture of urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate was changed to 70 parts of urethane (meth) acrylate compound (A′-2) obtained above. In the same manner as described above, an active energy ray-curable resin composition was obtained.

<Comparative Example 5>
In Example 2, in the same manner except that 30 parts of the urethane (meth) acrylate compound (B-1) was changed to 30 parts of the urethane (meth) acrylate compound (B′-2) obtained above, An active energy ray-curable resin composition was obtained.

<Comparative Example 6>
30 parts of a mixture of urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate obtained above, 70 parts of urethane (meth) acrylate compound (B-1), 1-hydroxy as photoinitiator 4-Cyclohexyl-phenyl-ketone (manufactured by BASF Japan Ltd .; "Irgacure 184") and 100 parts of ethyl acetate as a diluent solvent were uniformly mixed to obtain an active energy ray-curable resin composition.

<Comparative Example 7>
40 parts of a mixture of urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate obtained above, 60 parts of urethane (meth) acrylate compound (B-1), 1-hydroxy as photoinitiator 4-Cyclohexyl-phenyl-ketone (manufactured by BASF Japan Ltd .; "Irgacure 184") and 100 parts of ethyl acetate as a diluent solvent were uniformly mixed to obtain an active energy ray-curable resin composition.

<Comparative Example 8>
100 parts of a mixture of the urethane (meth) acrylate compound (A-1) and pentaerythritol tetraacrylate obtained above, 4 parts of Irgacure 184 as a photoinitiator, and 100 parts of ethyl acetate as a diluting solvent are uniformly mixed. An active energy ray-curable resin composition was obtained.

<Comparative Example 9>
100 parts of urethane (meth) acrylate compound (B-1) obtained above, 4 parts of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF Japan Ltd .; “Irgacure 184”) as a photoinitiator, diluted 100 parts of ethyl acetate as a solvent was uniformly mixed to obtain an active energy ray-curable resin composition.

The active energy ray-curable resin composition is coated on a 125 μm thick PET film provided with an easy-adhesion layer using a bar coater so that the film thickness after drying is 5 μm, and dried at 60 ° C. for 3 minutes. I let you. Thereafter, using a high pressure mercury lamp 80W and one lamp, two passes of ultraviolet irradiation (integrated irradiation amount 500 mJ / cm ² ) were performed at a conveyor speed of 5.1 m / min from a height of 18 cm to form a cured coating film. .
The following evaluation was performed about the obtained cured coating film.

(Pencil hardness)
About the said cured coating film, pencil hardness was measured according to JISK5600-5-4.

(Abrasion resistance)
About the said cured coating film, the surface damage | wound degree after visually reciprocating steel wool # 0000 which applied the load of 500g or 100g 10 times on the cured coating film surface was observed visually, and it evaluated as follows.
(Evaluation)
◎ ・ ・ ・ No damage at all ○ ・ ・ ・ Slightly scratched △ ・ ・ ・ Slightly scratched × ・ ・ ・ Thin film is whitened due to damage

(Flexibility)
The cured coating film was evaluated for flexibility using a cylindrical mandrel bending tester according to JIS K 5600-5-1. When the cured coating film for evaluation was wound around a test bar, the maximum diameter (integer value, mm) at which cracking or peeling occurred was measured and evaluated as follows.
(Evaluation)
◎ ... Less than 2 (No cracking occurs even with a diameter of 2 mm)
○ ・ ・ ・ 2-3
△ ... 4-5
× ・ ・ ・ 6 or more

(Curl resistance)
About the said cured coating film, the sample was cut out to 10 cm x 10 cm square, and it set | placed on the horizontal surface, the average value of the four corners lift was measured, and it evaluated as follows.
(Evaluation)
◎ ・ ・ ・ No lift at all ○ ・ ・ ・ With a lift of 1 mm or less △ ・ ・ ・ With a lift of over 1 mm and 5 mm or less × ・ ・ ・ With a lift of over 5 mm

PE3A: Pentaerythritol triacrylate PE4A: Pentaerythritol tetraacrylate DPHA: Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate In the table, "-" indicates that it is not blended.

  The cured coating film obtained from the active energy ray-curable resin composition of Examples 1 to 6 has an isocyanurate skeleton, and has a high concentration of ethylenically unsaturated groups (A) and urethane (meth) acrylate compound (A). The composition is derived from an alicyclic structure-containing isocyanate and contains a urethane (meth) acrylate compound (B) having a low ethylenically unsaturated group concentration, and the content ratio [(A) / (B)] is 1 or more. Since it is obtained from the product, it can be seen that the coating film has a good balance between scratch resistance and flexibility, has low curl properties and high hardness, and is a cured coating film with excellent flexibility and crack resistance.

  On the other hand, it can be seen that the cured coating films obtained from the active energy ray-curable resin compositions of Comparative Examples 1 to 9 are insufficient in either scratch resistance or flexibility or both. Moreover, it turns out that either the curl property and hardness are inadequate in the cured coating film in Comparative Examples 1-4 and 6-9.

The active energy ray-curable resin composition of the present invention includes various film forming materials such as paints, pressure-sensitive adhesives, adhesives, adhesives, inks, anchor coating agents, magnetic powder coating binders, sandblast coatings, and plate materials. Useful as. In particular, it is suitable as a coating agent for a coating material composition for coating a plastic substrate, a coating composition for coating a metal substrate, and the like.

Claims (5)

Urethane (meth) acrylate compound (A) obtained by reacting isocyanate compound (a1) and hydroxyl group-containing (meth) acrylate compound (a2), and isocyanate compound (b1), hydroxyl group-containing (meth) acrylate compound Urethane (meth) acrylate compound (B) obtained by reacting compound (b2) and polyol compound (b3)
An active energy ray-curable resin composition containing
The isocyanate compound (a1) is a compound having an isocyanurate skeleton, and the isocyanate compound (b1) is an alicyclic structure-containing isocyanate,
The ethylenically unsaturated group concentration of the urethane (meth) acrylate compound (A) is 3 mmol / g or more, and the ethylenically unsaturated group concentration of the urethane (meth) acrylate compound (B) is 1.5 mmol / g or more and 3 mmol. / G,
Active energy characterized in that the content ratio (weight ratio) [(A) / (B)] of the urethane (meth) acrylate compound (A) and the urethane (meth) acrylate compound (B) is 1 or more. A linear curable resin composition.   The active energy ray-curable resin composition according to claim 1, wherein the polyol compound (b3) is a polyester polyol and / or a polyether polyol.   The active energy ray-curable resin composition according to claim 1 or 2, wherein the polyol compound (b3) is a polyol compound containing three or more hydroxyl groups.   The active energy ray-curable resin composition according to any one of claims 1 to 3, wherein the urethane (meth) acrylate compound (B) has a weight average molecular weight of 1,000 to 100,000.   A coating agent comprising the active energy ray-curable resin composition according to claim 1.