JPWO2017110845A1 - Active energy ray-curable resin composition and method for producing the same - Google Patents

Abstract

As the active energy ray-curable resin composition suitably used for the pressure-sensitive adhesive composition and the coating composition without any change in viscosity over time, the following (A), (B) and (X) An active energy ray-curable resin composition containing a hydroxyl group-containing monomer (b1) as the following (B): (A) Urethane (meth) acrylate-based compound. (B) An ethylenically unsaturated monomer excluding (A) above. (X) Metal salt.

Description

  The present invention relates to an active energy ray-curable resin composition, and more specifically, the viscosity change with time is very small, the storage stability is excellent, and it is suitably used for an adhesive composition and a coating composition. The present invention relates to an active energy ray-curable resin composition.

  Conventionally, active energy ray-curable resin compositions have been widely used as coating agents, adhesives, adhesives, or anchor coating agents for various substrates because curing is completed by irradiation of active energy rays for a very short time. It has been. Such an active energy ray-curable resin composition is often blended with urethane (meth) acrylate and a photopolymerizable monomer, and preferably further with a photopolymerization initiator. Among them, urethane (meth) acrylate is flexible. It is very often used because it has properties such as tough coatings. In particular, in a urethane (meth) acrylate having a linear main chain, application to a pressure-sensitive adhesive composition or a coating agent composition is greatly expected.

  For example, in an adhesive used for an optical device such as a touch panel and an optical member such as an optical recording medium, a transparent pressure-sensitive adhesive sheet is used for bonding the optical member. In order to include a member having a step such as a printing step, the pressure-sensitive adhesive sheet is required to have excellent step following performance in addition to the adhesive strength. As means for imparting step following ability, it has been studied to increase the thickness of the pressure-sensitive adhesive layer or to use a flexible pressure-sensitive adhesive layer. Therefore, a urethane (meth) acrylate having a relatively high molecular weight. Is used.

There are various methods for the production of urethane (meth) acrylate, and as a commonly used method, (1) a method in which diisocyanate, diol, and hydroxyl group-containing (meth) acrylate are charged together and reacted (for example, patents) References 1 and 2), and (2) a method in which a diisocyanate and a diol are reacted to obtain a terminal isocyanate group-containing compound and then the terminal isocyanate group-containing compound and a hydroxyl group-containing (meth) acrylate are reacted. (For example, refer to Patent Documents 3 and 4).
In addition, in the production of urethane (meth) acrylates, various catalysts are generally used for the purpose of promoting the reaction. Among them, an organotin compound is generally used because of its high activity as a urethanization reaction catalyst. It is used.

JP 2013-56966 A JP 2014-5368 A JP 2011-162770 A JP 2002-309185 A

  However, in the above production methods (1) and (2), when the weight average molecular weight of urethane (meth) acrylate increases, the number of urethane bonds due to urethane reaction of diisocyanate and diol increases. And the viscosity in the system rises rapidly, so the reaction efficiency decreases. As a result, since a very small amount of unreacted isocyanate groups and hydroxyl groups still exist, the molecular weight of the urethane (meth) acrylate increases with the passage of time, that is, the viscosity increases with time, resulting in storage stability. This is a problem. As a result, the pressure-sensitive adhesive composition and coating agent using the same cause problems such as failure to obtain desired pressure-sensitive adhesive properties and coating film properties.

Therefore, the present inventor, as a method for suppressing the increase in viscosity over time, first, in order to reduce the residual amount of unreacted isocyanate groups as much as possible, the active energy ray-curable resin composition containing a large amount of hydroxyl group-containing monomer I found something.
However, the active energy ray-curable resin composition containing a large amount of the above hydroxyl group-containing monomer has suppressed the increase in viscosity over time, but this time the viscosity of the composition will decrease over time. A new problem has arisen.

  Therefore, the present invention is an active energy ray-curable resin composition that is excellent in storage stability without causing a change in viscosity over time and is suitably used for a pressure-sensitive adhesive composition or a coating agent composition, and its The object is to provide a manufacturing method.

  However, as a result of intensive studies in view of such circumstances, the present inventor has obtained a urethane (meth) acrylate compound in an active energy ray-curable resin composition in which a urethane (meth) acrylate compound and a hydroxyl group-containing monomer are used in combination. Active energy ray curing with excellent storage stability over time by using a urethane (meth) acrylate compound that uses a metal salt that is not normally used for the production of a urethane (meth) acrylate compound as a catalyst. The present invention was completed by finding that a functional resin composition was obtained.

  That is, the present invention is an active energy ray-curable resin composition containing a urethane (meth) acrylate compound (A), an ethylenically unsaturated monomer (B) excluding the above (A), and a metal salt (X). The active energy ray-curable resin composition is characterized by containing a hydroxyl group-containing monomer (b1) as the ethylenically unsaturated monomer (B). This is the second gist.

The active energy ray-curable resin composition obtained in the present invention is an active energy ray-curable resin composition containing the following (A), (B), and (X), and a hydroxyl group-containing monomer as the following (B): By containing (b1), the viscosity change with time is very small and the storage stability is excellent, so that it is suitably used for a pressure-sensitive adhesive composition or a coating agent composition.
(A) Urethane (meth) acrylate-based compound.
(B) An ethylenically unsaturated monomer excluding (A) above.
(X) Metal salt.

Moreover, content of the said metal salt (X) is 1 * 10 < ^-3 > -1 * with respect to a total of 100 weight part of the said urethane (meth) acrylate type compound (A) and the said ethylenically unsaturated monomer (B). When it is 10 ⁻¹ parts by weight, the viscosity change with time is further reduced.

  Furthermore, the urethane (meth) acrylate compound (A) is a urethane (meth) acrylate compound having at least one of an ester bond and a carbonate bond other than the ester bond in the (meth) acryloyloxy group. Thus, the effect of the present invention can be obtained with a high change in viscosity with time and excellent storage stability.

  And since the (meth) acryloyl equivalent of the said urethane (meth) acrylate type compound (A) is 5,000-100,000, since a flexible cured coating film is obtained and it becomes an appropriate viscosity range, Easy handling.

  Moreover, content of the said hydroxyl-containing monomer (b1) is 20-70 weight part with respect to a total of 100 weight part of the said urethane (meth) acrylate type compound (A) and the said ethylenically unsaturated monomer (B). As a result, the viscosity stability over time is further improved.

  Further, the urethane (meth) acrylate compound (A) is a reaction product of a polyvalent isocyanate compound (a1), a hydroxyl group-containing (meth) acrylate compound (a2), and a polyol compound (a3). The effect of the present invention that the change in viscosity due to is small and the storage stability is excellent is obtained.

  When the polyol compound (a3) is at least one of a polyester polyol and a polycarbonate polyol, the effects of the present invention can be easily obtained and the versatility is excellent.

  When the metal salt (X) is a fatty acid metal salt having 8 to 10 carbon atoms, a suitable catalytic ability is exhibited and the reactivity becomes excellent.

Furthermore, it is a method for producing an active energy ray-curable resin composition containing the following (A), (B) and (X), and containing the hydroxyl group-containing monomer (b1) as the following (B): The acrylate compound (A) is reacted with the polyvalent isocyanate compound (a1), the hydroxyl group-containing (meth) acrylate compound (a2), and the polyol compound (a3) in the presence of the metal salt (X). With the method for producing an active energy ray-curable resin composition to be obtained, an active energy ray-curable resin composition having very little change in viscosity with time and excellent storage stability can be obtained.
(A) Urethane (meth) acrylate-based compound.
(B) An ethylenically unsaturated monomer excluding (A) above.
(X) Metal salt.

When the metal salt (X) is blended so as to be 5 × 10 ⁻³ to 1 × 10 ⁻¹ parts by weight with respect to 100 parts by weight of the urethane (meth) acrylate compound (A) obtained as described above, the time elapses more. An active energy ray-curable resin composition in which the viscosity change due to is further reduced can be obtained.

The present invention will be described in detail below, but these show examples of desirable embodiments.
In the present invention, (meth) acrylic acid is acrylic acid or methacrylic acid, (meth) acryl is acrylic or methacrylic, (meth) acryloyl is acryloyl or methacryloyl, and (meth) acrylate is acrylate or Each means methacrylate. The acrylic resin is a resin obtained by polymerizing a polymerization component containing at least one (meth) acrylate monomer.

  The active energy ray-curable resin composition of the present invention contains a urethane (meth) acrylate compound (A), an ethylenically unsaturated monomer (B) and a metal salt (X). In the present invention, It is characterized by containing the metal salt (X). Hereinafter, each component which comprises the active energy ray curable resin composition of this invention is demonstrated.

[Metal salt (X)]
The metal salt (X) is preferably a fatty acid salt of a metal such as tin, bismuth, zinc or titanium, for example, tin octylate, tin decanoate, tin neodecanoate, tin laurate, tin myristate, or stearate. Bismuth octylate, bismuth decanoate, bismuth neodecanoate, bismuth laurate, zinc octylate, zinc decanoate, zinc neodecanoate, zinc laurate, titanium octylate, titanium decanoate, titanium neodecanoate, titanium laurate, etc. Can be mentioned. These can be used alone or in combination of two or more. Among them, preferred are fatty acid metal salts having 8 to 10 carbon atoms, particularly preferred are tin or bismuth fatty acid salts of 8 to 10 carbon atoms in terms of excellent reactivity, and particularly preferred are tin octylate and tin decanoate. , Tin neodecanoate, bismuth octylate, bismuth decanoate, bismuth neodecanoate.

The content of the metal salt (X) is described below of the urethane (meth) acrylate compound (A) and the ethylenically unsaturated monomer (B) a total of 1 to 100 parts by weight of × 10 ^-3 ~1 × 10 the ^{- The} amount is preferably ¹ part by weight, particularly preferably 2 × 10 ⁻³ to 8 × 10 ⁻² part by weight, and further preferably 3 × 10 ^{−3 to} 6 × 10 ⁻² part by weight.
When the content is too large, the viscosity tends to proceed, and when the content is too small, the molecular weight of the urethane (meth) acrylate compound (A) tends to decrease.

  The metal salt (X) may be blended as a catalyst during the production of the urethane (meth) acrylate compound (A), or the urethane (meth) acrylate compound (A), an ethylenically unsaturated monomer. In addition to (B), it may be blended as a single blending component, or may be a combination of both. However, a urethane (meth) acrylate compound ( It is preferable to be blended as a catalyst during the production of A).

[Urethane (meth) acrylate compound (A)]
The urethane (meth) acrylate compound (A) used in the present invention is obtained by reacting a polyvalent isocyanate compound (a1) and a hydroxyl group-containing (meth) acrylate compound (a2), or a polyvalent isocyanate compound. (A1), a hydroxyl group-containing (meth) acrylate compound (a2) and a polyol compound (a3) are reacted. In the present invention, a polyvalent isocyanate compound (a1), a hydroxyl group-containing compound ( A urethane (meth) acrylate compound obtained by reacting a (meth) acrylate compound (a2) and a polyol compound (a3) is preferable.
The urethane (meth) acrylate compound (A) used in the present invention is a urethane (meth) acrylate compound having at least one of an ester bond (excluding an ester bond in a (meth) acryloyl group) and a carbonate bond. It is preferable that it is easy to obtain the effects of the present invention.

Examples of the polyvalent isocyanate compound (a1) include aromatics such as tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate. Polyisocyanates; aliphatic polyisocyanates such as pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, lysine triisocyanate; alicyclic diisocyanates (for example, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, 1, 3-bis (isocyanato) Hexane, 1,4-bis (isocyanato) cyclohexane, norbornene diisocyanate, etc.) or the like, or trimer compounds or multimeric compounds of these polyisocyanates; allophanate type polyisocyanates, burette type polyisocyanates, etc. Can be mentioned.
These can be used alone or in combination of two or more.

  Among these, aliphatic diisocyanates such as pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate; hydrogenated diphenylmethane diisocyanate, 1,3-bis (isocyanato) cyclohexane, 1 , 4-bis (isocyanato) cyclohexane, isophorone diisocyanate, norbornene diisocyanate, etc. are preferably used, particularly preferably alicyclic diisocyanate (especially isophorone diisocyanate, hydrogenated) in terms of low curing shrinkage. Diphenylmethane diisocyanate, 1,3-bis (isocyanato) cyclohexane, 1,4-bis (isocyanato) cyclohexane) Preferably, from the viewpoint of excellent reactivity and versatility, 1,3-bis (isocyanato) cyclohexane, isophorone diisocyanate is used.

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 (meta). ) Acrylates, hydroxyalkyl (meth) acrylates 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 ( Acrylate), 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, glycerol mono (meth) acrylate, glycerol di (meth) acrylate, 2-hydroxy-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 Examples include dipentaerythritol penta (meth) acrylate.
These can be used alone or in combination of two or more.

  Among these, a hydroxyl group-containing (meth) acrylate-based compound having one ethylenically unsaturated group is preferable in terms of excellent flexibility of the pressure-sensitive adhesive layer, and more preferably 2-hydroxyethyl (meth) acrylate, 2- Hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxyalkyl (meth) acrylate such as 6-hydroxyhexyl (meth) acrylate, and glycerin mono (meth) acrylate In particular, it is preferable to use 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and glycerin mono (meth) acrylate in terms of excellent reactivity and versatility.

  Examples of the polyol compound (a3) include polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, (meth) acrylic polyols, polysiloxane polyols, and the like. These can be used alone or in combination of two or more.

  Examples of polyether polyols include polyether polyols containing alkylene structures such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, and polyhexamethylene glycol, and random or block copolymers of these polyalkylene glycols. Etc.

  Examples of the polyester polyol include three kinds of components such as a condensation polymer of polyhydric alcohol and polycarboxylic acid, a ring-opening polymer of cyclic ester (lactone), polyhydric alcohol, polycarboxylic acid and cyclic ester. Examples include reactants.

  Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,4-tetramethylene diol, 1,3-tetramethylene diol, 2-methyl-1,3-trimethyl. Methylene diol, 1,5-pentamethylene diol, neopentyl glycol, 1,6-hexamethylene diol, 3-methyl-1,5-pentamethylene diol, 2,4-diethyl-1,5-pentamethylene diol, glycerin , Trimethylolpropane, trimethylolethane, cyclohexanediols (such as 1,4-cyclohexanediol), bisphenols (such as bisphenol A), sugar alcohols (such as xylitol and sorbitol), 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 dodecanedioic acid; -Alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, paraphenylenedicarboxylic 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 ring-opening polymer of a cyclic carbonate (alkylene carbonate, etc.), and the like.

  Examples of the polyhydric alcohol include polyhydric alcohols exemplified in the description of the polyester-based polyol. Examples of the alkylene carbonate include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, and hexamethylene carbonate. It is done.

  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. For example, polyisoprene polyol, polybutadiene polyol, nitrile butadiene polyol, styrene butadiene polyol, and the like can be given.
The polyolefin-based polyol may be a hydrogenated polyolefin-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 polymer or copolymer molecule of (meth) acrylic acid ester. As such (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 the polysiloxane polyol include dimethyl polysiloxane polyol and methylphenyl polysiloxane polyol.

  Among these, polyester-based polyols, polyether-based polyols, and polycarbonate-based polyols are preferable, and polyester-based polyols and polycarbonate-based polyols are particularly preferable in that the effects of the present invention can be easily obtained and the versatility is excellent.

  The number of hydroxyl groups contained in the polyol compound (a3) is preferably 2 to 5, particularly preferably 2 to 3, and more preferably 2. If the number of hydroxyl groups is too large, gelation tends to occur during the reaction.

  In the present invention, the polyol compound (a3) preferably has a weight average molecular weight of 1,000 to 20,000, particularly preferably 2,000 to 18,000, and more preferably 3,000 to 16,000. is there. If the weight average molecular weight is too small, the adhesive strength of the pressure-sensitive adhesive layer tends to be reduced, and if it is too large, the reactivity with the polyvalent isocyanate compound (a1) tends to be reduced.

In addition, said weight average molecular weight is a weight average molecular weight by standard polystyrene molecular weight conversion, column: Shodex GPC KF-806L (exclusion) in a high performance liquid chromatography (Showa Denko Co., Ltd. make, "Shodex GPC system-11 type | mold"). Limit molecular weight: 2 × 10 ⁷ , separation range: 100 to 2 × 10 ⁷ , theoretical plate number: 10,000 plate / piece, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm) Measured by using series.

  As a hydroxyl value of the said polyol type compound (a3), it is preferable that it is 10-300 mgKOH / g, Especially preferably, it is 15-150 mgKOH / g, More preferably, it is 20-120 mgKOH / g. If the hydroxyl value is too high, the urethane (meth) acrylate compound (A) tends to have a low molecular weight and the adhesive strength tends to decrease, and if it is too low, the viscosity tends to increase and the workability tends to decrease.

  Examples of the urethane (meth) acrylate compound (A) used in the present invention include (1) the polyvalent isocyanate compound (a1), the hydroxyl group-containing (meth) acrylate compound (a2), and the polyol compound (a3). ) In a reactor in a batch or separately, and (2) a reaction product obtained by reacting a polyvalent isocyanate compound (a1) and a polyol compound (a3) in advance with a hydroxyl group-containing (meta ) A method of reacting the acrylate compound (a2) and the like can be mentioned, and the method (2) is preferable from the viewpoints of reaction stability and reduction of by-products.

  For the reaction of the polyvalent isocyanate compound (a1) and the polyol compound (a3), known reaction means can be used. In that case, for example, the molar ratio of the isocyanate group in the polyvalent isocyanate compound (a1) to the hydroxyl group in the polyol compound (a3) is usually about 2n: (2n-2) (n is an integer of 2 or more). Thus, a terminal isocyanate group-containing urethane (meth) acrylate-based compound in which an isocyanate group remains can be obtained. After obtaining the compound, an addition reaction with the hydroxyl group-containing (meth) acrylate-based compound (a2) is performed. to enable.

  The addition reaction of the reaction product obtained by reacting the polyvalent isocyanate compound (a1) and the polyol compound (a3) in advance with the hydroxyl group-containing (meth) acrylate compound (a2) is also a known reaction. Means can be used.

  The reaction molar ratio between the reaction product and the hydroxyl group-containing (meth) acrylate compound (a2) is, for example, that the polyisocyanate compound (a1) has two isocyanate groups and the hydroxyl group-containing (meth) acrylate compound (a2). ) Has one hydroxyl group, the reaction product: hydroxyl group-containing (meth) acrylate compound (a2) is about 1: 2, and the polyisocyanate compound (a1) has three isocyanate groups. When the hydroxyl group-containing (meth) acrylate compound (a2) has one hydroxyl group, the reaction product: hydroxyl group-containing (meth) acrylate compound (a2) is about 1: 3.

  In the addition reaction between the reaction product and the hydroxyl group-containing (meth) acrylate compound (a2), the reaction is terminated when the residual isocyanate group content in the reaction system is 0.1% by weight or less. A (meth) acrylate compound (A) is obtained.

  The reaction temperature at the time of the said reaction is 30-90 degreeC normally, Preferably it is 40-80 degreeC, and reaction time is 2 to 30 hours normally, Preferably it is 3 to 20 hours.

  In the present invention, when the urethane (meth) acrylate compound (A) is produced, the metal salt (X) is used as a catalyst, the polyvalent isocyanate compound (a1), the hydroxyl group-containing (meth) acrylate compound ( It is preferable that a urethane (meth) acrylate compound (A) is obtained by reacting a2) and the polyol compound (a3) in the presence of the metal salt (X).

The amount of the metal salt (X) used as a catalyst during the production of the urethane (meth) acrylate compound (A) is 5 × with respect to 100 parts by weight of the urethane (meth) acrylate compound (A). It is preferable to mix | blend so that it may become 10 < ^-3 > ^-1 * 10 <^-1> weight part, Especially preferably, it is 6 * 10 ^{< -3} > -9 * 10 ^<-2> weight part, More preferably, it is 7 * 10 < ^-3 > -8 * 10. ^-2 parts by weight.
If the blending amount is too small, the molecular weight of the urethane (meth) acrylate compound (A) tends to decrease, and if it is too large, the viscosity tends to decrease.

In the production of the urethane (meth) acrylate compound (A) obtained by reacting the polyvalent isocyanate compound (a1), the hydroxyl group-containing (meth) acrylate compound (a2) and the polyol compound (a3), as necessary. Organic solvents having no functional group that reacts with isocyanate groups, for example, esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and organic solvents such as aromatics such as toluene and xylene May be used.
Further, in place of the organic solvent or in combination with the organic solvent, an ethylenically unsaturated monomer (B) described later can be used as a diluent.
In the present invention, when the urethane (meth) acrylate compound (A) has a high molecular weight, the viscosity increases and handling becomes worse. Therefore, it is preferable to use an ethylenically unsaturated monomer (B) described later as a diluent.

  Thus, the urethane (meth) acrylate compound (A) used in the present invention is produced.

  The (meth) acryloyl equivalent of the urethane (meth) acrylate compound (A) is preferably 5,000 to 100,000, particularly preferably 6,000 to 90,000, and more preferably 7,000 to 80. 1,000, particularly preferably 8,000 to 70,000. If the (meth) acryloyl equivalent is too low, the adhesive strength of the pressure-sensitive adhesive layer tends to decrease when used as a pressure-sensitive adhesive. If it is too high, the viscosity of the urethane (meth) acrylate compound (A) becomes too high. It tends to be difficult to handle.

  The weight average molecular weight of the urethane (meth) acrylate compound (A) is preferably 5,000 to 200,000, particularly preferably 6,000 to 150,000, and more preferably 7,000 to 120,000. Particularly preferably, it is 8,000 to 100,000. If the weight average molecular weight is too low, the adhesive strength of the pressure-sensitive adhesive layer tends to decrease, and if it is too high, the viscosity of the urethane (meth) acrylate compound (A) tends to be too high and handling tends to be difficult.

In addition, said weight average molecular weight is a weight average molecular weight by standard polystyrene molecular weight conversion, column: Shodex GPC KF-806L (exclusion) in a high performance liquid chromatography (Showa Denko Co., Ltd. make, "Shodex GPC system-11 type | mold"). Limit molecular weight: 2 × 10 ⁷ , separation range: 100 to 2 × 10 ⁷ , theoretical plate number: 10,000 plate / piece, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm) Measured by using series.

Further, the viscosity of the urethane (meth) acrylate compound (A) is preferably 1,000 to 10,000,000 mPa · s, particularly preferably 2,000 to 8,000, as the viscosity at 60 ° C. 000 mPa · s, more preferably 3,000 to 6,000,000 mPa · s. If the viscosity is too high, handling tends to be difficult, and if it is too low, control of the film thickness tends to be difficult during coating.
In addition, the measuring method of a viscosity is based on an E-type viscometer.

[Ethylenically unsaturated monomer (B)]
In the present invention, it is necessary to contain the hydroxyl group-containing monomer (b1) as the ethylenically unsaturated monomer (B).

Examples of the hydroxyl group-containing monomer (b1) include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 8-hydroxy. C1-C16 (preferably 1-12) (meth) of alkyl groups such as octyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) acrylate, etc. Caprolactone-modified monomers such as hydroxyalkyl acrylate, caprolactone-modified 2-hydroxyethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, 2-acrylic Primary hydroxyl group-containing ethylenically unsaturated compounds such as iroxyethyl-2-hydroxyethylphthalic acid, N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide; 2-hydroxypropyl (meth) acrylate, 2- Secondary hydroxyl groups such as hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate -Containing ethylenically unsaturated compounds; tertiary hydroxyl group-containing ethylenically unsaturated compounds such as 2,2-dimethyl-2-hydroxyethyl (meth) acrylate.
Among these, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate are excellent in viscosity and compatibility with acrylic resins, and easily available. 2-hydroxybutyl (meth) acrylate, more preferably 4-hydroxybutyl (meth) acrylate.
Moreover, these can be used individually by 1 type or in combination of 2 or more types.

The content of the hydroxyl group-containing monomer (b1) is preferably 40% by weight or more, particularly preferably 45% by weight or more, more preferably 50% by weight or more, based on the entire ethylenically unsaturated monomer (B). is there.
If the content is too small, the viscosity tends to increase.

Moreover, content of this hydroxyl-containing monomer (b1) is 20-70 weight part with respect to a total of 100 weight part of a urethane (meth) acrylate type compound (A) and an ethylenically unsaturated monomer (B). Is preferably 20 to 65 parts by weight, more preferably 25 to 60 parts by weight.
When the content is too large, the viscosity tends to proceed easily, and when the content is too small, the viscosity tends to proceed easily.

  The hydroxyl group-containing monomer (b1) may be separately added to the urethane (meth) acrylate compound (A), or as a diluent during the production of the urethane (meth) acrylate compound (A). It may be blended.

  Further, as the ethylenically unsaturated monomer (B), an ethylenically unsaturated monomer (b2) other than the hydroxyl group-containing monomer (b1) (hereinafter sometimes referred to as “ethylenically unsaturated monomer (b2)”). The ethylenically unsaturated monomer (b2) may be any of a monofunctional monomer, a bifunctional monomer, and a trifunctional or higher monomer.

  As a monofunctional monomer, what is necessary is just a monomer containing one ethylenically unsaturated group, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, n-stearyl (meth) acrylate, isostearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate Benzyl (meth) acrylate, phenol ethylene oxide modified (meth) acrylate, nonylphenol propylene oxide modified (meth) acrylate, 2-methoxyethyl (meth) acrylate, ethyl carbitol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxy Polypropylene glycol (meth) acrylate, butoxyethyl (meth) acrylate, acryloylmorpholine, N-vinylpyrrolidone, 2-vinylpyridine, glycidyl (meth) acrylate, 3-ethyl-3-oxetanylmethyl (meth) acrylate, furfuryl (meth) ) Acrylate, tetrahydrofurfuryl (meth) acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl (Meth) acrylate, cyclohexanespiro-2- (1,3-dioxolan-4-yl) methyl (meth) acrylate, γ-butyrolactone (meth) acrylate, trimethylolpropane (formal) (meth) acrylate, styrene, vinyltoluene, Examples include chlorostyrene, α-methylstyrene, acrylonitrile, vinyl acetate, allyl (meth) acrylate, and 2- (meth) acryloyloxyethyl acid phosphate monoester.

  In addition to the monofunctional monomer, there may be mentioned a Michael adduct of acrylic acid or 2-acryloyloxyethyl dicarboxylic acid monoester. Examples of the Michael adduct of acrylic acid include acrylic acid dimer, methacrylic acid dimer, acrylic Examples include acid trimer, methacrylic acid trimer, acrylic acid tetramer, and methacrylic acid tetramer. Examples of 2-acryloyloxyethyl dicarboxylic acid monoester which is a carboxylic acid having a specific substituent include 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, and 2-acryloyloxyethyl. Examples include phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, and 2-methacryloyloxyethyl hexahydrophthalic acid monoester. Furthermore, oligoester acrylate is also mentioned.

  The bifunctional monomer may be any monomer containing two ethylenically unsaturated groups. For example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol Di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide Modified bisphenol A type di (meth) acrylate, propylene oxide modified bisphenol A type di (meth) acrylate, 1,6-hexanediol di (meth) acrylate 1,6-hexanediol ethylene oxide modified di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, diglycidyl phthalate di (meth) acrylate, hydroxypivalic acid modified neopentyl glycol di (meth) Acrylate, 2- (meth) acryloyloxyethyl acid phosphate diester, etc. are mentioned.

  The tri- or higher functional monomer may be any monomer containing three or more ethylenically unsaturated groups. For example, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) ) Acrylate, tri (meth) acryloyloxyethoxytrimethylolpropane, isocyanuric acid ethylene oxide modified triacrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, ethylene oxide modified pentaerythritol tetra (meth) acrylate, caprolactone modified dipentaerythritol Examples include hexa (meth) acrylate and caprolactone-modified pentaerythritol tetra (meth) acrylate.

  These may be used alone or in combination of two or more.

  Among the ethylenically unsaturated monomers (b2), it is preferable to use a monofunctional monomer in terms of excellent flexibility of the coating film, and methyl (meth) acrylate and ethyl in terms of excellent yellowness and good flexibility. (Meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate , Decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, n-stearyl (meth) acrylate, isostearyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, ethyl carbitol (meth) acrylate , Methoxy Triethylene glycol (meth) acrylate, methoxy polypropylene glycol (meth) acrylate, butoxyethyl (meth) acrylate are particularly preferred.

  The ethylenically unsaturated monomer (b2) is preferably used as a diluent during the production of the urethane (meth) acrylate compound (A).

[Active energy ray-curable resin composition]
The active energy ray-curable resin composition of the present invention is obtained using the urethane (meth) acrylate compound (A), the ethylenically unsaturated monomer (B), and the metal salt (X).

The content ratio (weight ratio) between the urethane (meth) acrylate compound (A) and the ethylenically unsaturated monomer (B) is usually (A) :( B) = 80: 20 to 20:80, preferably (A) :( B) = 75: 25-25: 75, particularly preferably (A) :( B) = 70: 30-25: 75, more preferably (A) :( B) = 65: 35 ~ 30: 70.
If the amount of the ethylenically unsaturated monomer (B) is too much with respect to the urethane (meth) acrylate compound (A), the viscosity of the resin composition tends to be too low and thick coating tends to be difficult. The viscosity of the composition tends to be too high and becomes difficult to handle.

The active energy ray-curable resin composition of the present invention preferably further contains a photopolymerization initiator (C) in order to efficiently perform curing with active energy rays.
The photopolymerization initiator (C) is not particularly limited as long as it generates radicals by the action of light. For example, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one , Benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propane-1 -One, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone, 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer, 1- [ 4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1 Acetophenones such as ON, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one; benzoin, benzoin methyl Benzoins such as ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; 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 ] Benzene metanaminium bromide, Benzophenones such as 4-benzoylbenzyl) 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-one mesochloride and other thioxanthones; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,6-dimethoxy) And acylphosphones such as benzoyl) -2,4,4-trimethyl-pentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; These photopolymerization initiators (C) can be used alone or in combination of two or more.

  Examples of auxiliary agents for the photopolymerization initiator (C) include triethanolamine, triisopropanolamine, 4,4′-dimethylaminobenzophenone (Michler ketone), 4,4′-diethylaminobenzophenone, 2-dimethylaminoethyl. Benzoic acid, ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone 2,4-diisopropylthioxanthone can also be used in combination. These auxiliaries can be used alone or in combination of two or more.

  About content of this photoinitiator (C), it is 1-10 weight part with respect to a total of 100 weight part with a urethane (meth) acrylate type compound (A) and an ethylenically unsaturated monomer (B). It is preferably 2 to 5 parts by weight. If the content is too small, the curing rate tends to decrease. If the content is too large, the curability does not improve and the economy tends to decrease.

  The active energy ray-curable resin composition of the present invention includes urethane (meth) acrylate compound (A), ethylenically unsaturated monomer (B), and metal salt (X), if necessary, photopolymerization start In addition to the agent (C), other than the above, the antioxidant, flame retardant, antistatic agent, filler, leveling agent, stabilizer, reinforcing agent, matting agent, and other than (X), as long as the effects of the present invention are not impaired. It is also possible to contain a reaction catalyst or the like. Furthermore, as the crosslinking agent, a compound having an action of causing crosslinking by heat, specifically, an epoxy compound, an aziricin compound, a melamine compound, an isocyanate compound, a chelate compound, and the like can be used.

Furthermore, the active energy ray-curable resin composition of the present invention can contain a polythiol compound from the viewpoint of suppressing unreacted components and improving adhesive strength.
Although it does not restrict | limit especially as a polythiol compound, The compound which has 2-6 mercapto groups in a molecule | numerator is preferable, for example, aromatic polythiols, such as C2-C20 alkanedithiol, aromatics, such as xylylene dithiol Polythiols, polythiols obtained by replacing halogen atoms of halohydrin adducts of alcohols with mercapto groups, polythiols comprising hydrogen sulfide reaction products of polyepoxide compounds, polyhydric alcohols having 2 to 6 hydroxyl groups in the molecule And polythiols composed of esterified products with thioglycolic acid, β-mercaptopropionic acid, or β-mercaptobutanoic acid, and the like. These can be used alone or in combination of two or more. .

  The content of the polythiol compound is preferably 0.01 to 10 parts by weight or less with respect to 100 parts by weight of the total of the urethane (meth) acrylate compound (A) and the ethylenically unsaturated monomer (B). It is particularly preferably 1 to 5 parts by weight or less.

In addition, the active energy ray-curable resin composition of the present invention comprises alcohols such as methanol, ethanol, propanol, n-butanol, i-butanol, etc. in order to adjust the viscosity at the time of coating, if necessary; acetone Ketones such as methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone; cellosolves such as ethyl cellosolve; aromatics such as toluene and xylene; glycol ethers such as propylene glycol monomethyl ether; acetic acid such as methyl acetate, ethyl acetate and butyl acetate Esters; dilute solvents such as diacetone alcohol may be used, but the solvent may remain in the coating film and the curing component may volatilize during drying. preferable.
Note that “substantially free of solvent” is usually 1% by weight or less, preferably 0.5% by weight or less, more preferably 0.1% by weight or less, based on the entire active energy ray-curable resin composition. Refers to that.

  The active energy ray-curable resin composition obtained in the present invention is cured by irradiating active energy rays after being applied on various substrates and dried.

  The application method of the active energy ray-curable resin composition is not particularly limited, and for example, spray, shower, dipping, roll, spin, curtain, flow, slit, die, gravure, comma, dispenser, Examples include wet coating methods such as screen printing and ink jet printing. As a coating method when the active energy ray-curable resin composition is a solid or a high-viscosity liquid, the active energy ray-curable resin composition is heated to reduce the viscosity, and then applied by the above method. The melt method is mentioned.

  As such active energy rays, rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays, electromagnetic waves such as X rays and γ rays, electron beams, proton rays, neutron rays, etc. can be used. Curing by ultraviolet irradiation is advantageous from the viewpoint of easy availability and price. In addition, when performing electron beam irradiation, it can harden | cure even without using a photoinitiator (C).

As a method of curing by ultraviolet irradiation, using a high pressure mercury lamp that emits light in a wavelength range of 150 to 450 nm, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a chemical lamp, an electrodeless discharge lamp, an LED, etc. What is necessary is just to irradiate about 30-3,000 mJ / cm < ² >.
After the ultraviolet irradiation, heating can be performed as necessary to complete the curing.

  Examples of the base material to which the active energy ray-curable resin composition obtained in the present invention is applied include polyolefin resin, polyester resin, polycarbonate resin, acrylonitrile butadiene styrene copolymer (ABS), and polystyrene resin. , Polyamide resins, etc. and their molded products (films, sheets, cups, etc.), metal substrates (metal vapor deposition layers, metal plates (copper, stainless steel (SUS304, SUSBA, etc.), aluminum, zinc, magnesium, etc.)), These composite base materials, such as glass, are mentioned.

  The thickness of the cured coating film is usually preferably 1 to 300 μm, particularly preferably 2 to 250 μm, and more preferably 5 to 200 μm.

  The active energy ray-curable resin composition obtained in the present invention is very useful as an adhesive composition or a coating agent composition.

The present inventor has found that the catalyst used in the production of the urethane (meth) acrylate compound remains in the urethane (meth) acrylate compound, the urethane bond in the urethane (meth) acrylate, the hydroxyl group-containing monomer, However, it was speculated that a transesterification reaction was caused by the catalyst, thereby reducing the molecular weight of the urethane (meth) acrylate compound, and as a result, the viscosity was lowered with time.
When the urethane (meth) acrylate compound has at least one of an ester bond and a carbonate bond, at least one of the ester bond and the carbonate bond in the urethane (meth) acrylate compound and a hydroxyl group-containing monomer However, it was presumed that a transesterification reaction occurred and the viscosity decreased with time. Under these presumed mechanisms, intensive studies were made to arrive at the present invention.

  In addition, when a metal salt is used in the active energy ray-curable resin composition as in the present invention, metal atoms are shielded electronically compared to the case of an organometallic compound having a large oxidation number such as dibutyltin dilaurate. As a result, since the interaction between the urethane bond, ester bond, carbonate bond in the urethane (meth) acrylate compound, the hydroxyl group in the hydroxyl group-containing monomer and the metal atom is weakened, the ester decomposition reaction proceeds. It is presumed that the effect of the present invention that the change in viscosity with time is very small and the storage stability is excellent is exhibited due to the fact that it is difficult to do.

  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 the like mean weight standards.

<Urethane (meth) acrylate compound (A)>
Urethane (meth) acrylate compounds (A-1) to (A-6) were produced as urethane (meth) acrylate compounds (A) as follows.

[Production Example 1]
In a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet, 4.2 g (0.019 mol) of isophorone diisocyanate (a1), bifunctional polyester polyol (a3) (Mw = 12,000) ) 65.2 g (0.016 mol), ethyl carbitol acrylate (b2-1) 30 g, tin octylate (X-1) 0.01 g as a reaction catalyst, 2,6-di-tert-butyl as a polymerization inhibitor After adding 0.04 g of cresol and reacting at 70 ° C. for 10 hours, 0.6 g (0.005 mol) of 2-hydroxyethyl acrylate (a2) was charged and reacted at 60 ° C. for 6 hours. The reaction was terminated when the residual isocyanate group reached 0.1%, and the urethane (meth) acrylate compound (A-1) (weight average molecular weight (Mw); 74,000) and ethyl carbitol acrylate (b2- The mixture of 1) was obtained.

[Production Example 2]
In a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet, 8.7 g (0.045 mol) of 1,3-bis (isocyanato) cyclohexane (a1), glycerin monomethacrylate (a2) 3.7 g (0.022 mol), 0.01 g of tin octylate (X-1) as a reaction catalyst, 0.04 g of 2,6-di-tert-butylcresol as a polymerization inhibitor were charged, and the mixture was heated at 60 ° C. for 7 hours. After the reaction, 87.6 g (0.045 mol) of a bifunctional polycarbonate polyol (a3) (Mw = 7,000) was charged and reacted at 60 ° C. for 10 hours. The reaction was terminated when the residual isocyanate group reached 0.1%, and a urethane (meth) acrylate compound (A-2) (weight average molecular weight (Mw); 16,000) was obtained.

[Production Example 3]
In a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet, 8.7 g (0.045 mol) of 1,3-bis (isocyanato) cyclohexane (a1), glycerin monomethacrylate (a2) 3.7 g (0.022 mol), 0.01 g of tin neodecanoate (X-2) as a reaction catalyst, and 0.04 g of 2,6-di-tert-butylcresol as a polymerization inhibitor were charged, and the mixture was heated at 60 ° C. for 7 hours. After the reaction, 87.6 g (0.045 mol) of a bifunctional polycarbonate polyol (a3) (Mw = 7,000) was charged and reacted at 60 ° C. for 10 hours. The reaction was terminated when the residual isocyanate group reached 0.1%, and a urethane (meth) acrylate compound (A-3) (weight average molecular weight (Mw); 16,000) was obtained.

[Production Example 4]
In a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet, 8.7 g (0.045 mol) of 1,3-bis (isocyanato) cyclohexane (a1), glycerin monomethacrylate (a2) 3.7 g (0.022 mol), 0.01 g of bismuth octylate (X-3) as a reaction catalyst, 0.04 g of 2,6-di-tert-butylcresol as a polymerization inhibitor were charged, and the mixture was heated at 60 ° C. for 7 hours. After the reaction, 87.6 g (0.045 mol) of a bifunctional polycarbonate polyol (a3) (Mw = 7,000) was charged and reacted at 60 ° C. for 10 hours. The reaction was terminated when the residual isocyanate group reached 0.1%, and a urethane (meth) acrylate compound (A-4) (weight average molecular weight (Mw); 14,000) was obtained.

[Production Example 5]
In the above Production Example 1, the reaction was carried out in the same manner except that the reaction catalyst was changed to 0.01 g of dibutyltin dilaurate (X′-1), and urethane (meth) acrylate compound (A-5) (weight average) A mixture of molecular weight (Mw); 75,000) and ethyl carbitol acrylate (b2-1) was obtained.

[Production Example 6]
In Production Example 2, the reaction was performed in the same manner except that the reaction catalyst was changed to 0.01 g of dibutyltin dilaurate (X′-1), and urethane (meth) acrylate compound (A-6) (weight average) Molecular weight (Mw); 16,000) was obtained.

<Ethylenically unsaturated monomer (B)>
The following were prepared as the ethylenically unsaturated monomer (B).
(B1-1): 4-hydroxybutyl acrylate (b2-1): ethyl carbitol acrylate

<Examples 1-5, Comparative Examples 1-3>
Each of the blended components (A) and (B) prepared and prepared as described above are blended so as to have a content ratio as shown in Table 1 below, and mixed uniformly to obtain an active energy ray-curable resin composition. Obtained.

  The active energy ray-curable resin compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were evaluated as follows. The results are shown in Table 1.

[Stability over time]
The active energy ray-curable resin composition was allowed to stand in a 60 ° C. dryer for 10 days, and a temporal stability test was performed. Viscosity was measured for each sample before and after the test, the rate of change in viscosity was calculated from the ratio, and storage stability was evaluated. The temperature for viscosity measurement was 20 ° C. in Examples 1 and 2 and Comparative Examples 1 and 2, and 60 ° C. in Examples 3 to 5 and Comparative Example 3. The viscosity was measured with an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., VISCOMETER TPE-100 type H).
(Evaluation criteria)
○ ・ ・ ・ Viscosity change rate is 95% or more and less than 105% × ・ ・ ・ Viscosity change rate is less than 95% or 105% or more

From the above evaluation results, the active energy ray-curable resin compositions of Examples 1 to 5 obtained using a urethane (meth) acrylate compound produced using a metal salt have a small viscosity change over time, It was excellent in storage stability.
On the other hand, the conventionally used active energy ray-curable resin compositions of Comparative Examples 1 and 3 containing urethane (meth) acrylate produced using dibutyltin dilaurate cause a decrease in viscosity over time. When it is put into practical use, problems such as unstable product state occur.
In addition, the active energy ray-curable resin composition of Comparative Example 2, which does not contain a hydroxyl group-containing monomer, has an increase in viscosity over time, causing problems such as unstable product state when used for practical use. Met.

  In the said Example, although the specific form in this invention was shown, the said Example is only a mere illustration and is not interpreted limitedly. Various modifications apparent to those skilled in the art are contemplated to be within the scope of this invention.

  The active energy ray-curable resin composition obtained by the production method of the present invention is very useful as a pressure-sensitive adhesive composition or a coating composition, particularly as a pressure-sensitive adhesive composition or a coating composition for optical members or optical films. It is. In particular, since a high molecular weight urethane (meth) acrylate compound can be made stably, it can be suitably used as an adhesive for bonding optical members excellent in durability, impact resistance and step following ability.

Claims (10)

Active energy ray-curable resin composition containing the following (A), (B) and (X), wherein the active energy ray-curable resin composition contains a hydroxyl group-containing monomer (b1) as the following (B): Resin composition.
(A) Urethane (meth) acrylate-based compound.
(B) An ethylenically unsaturated monomer excluding (A) above.
(X) Metal salt. The content of the metal salt (X) is, the urethane (meth) acrylate compound (A) and the ethylenically unsaturated monomer (B) total 100 parts by weight relative to 1 × 10 ^-3 ~1 × 10 the ^- The active energy ray-curable resin composition according to claim 1, which is ¹ part by weight.   The urethane (meth) acrylate compound (A) is a urethane (meth) acrylate compound having at least one of an ester bond and a carbonate bond other than an ester bond in a (meth) acryloyloxy group. The active energy ray-curable resin composition according to claim 1 or 2.   The active energy ray curable according to any one of claims 1 to 3, wherein the urethane (meth) acrylate compound (A) has a (meth) acryloyl equivalent of 5,000 to 100,000. Resin composition.   Content of the said hydroxyl-containing monomer (b1) is 20-70 weight part with respect to a total of 100 weight part of the said urethane (meth) acrylate type compound (A) and the said ethylenically unsaturated monomer (B). The active energy ray-curable resin composition according to any one of claims 1 to 4, wherein   The urethane (meth) acrylate compound (A) is a reaction product of a polyvalent isocyanate compound (a1), a hydroxyl group-containing (meth) acrylate compound (a2), and a polyol compound (a3). The active energy ray-curable resin composition according to any one of claims 1 to 5.   The active energy ray-curable resin composition according to claim 6, wherein the polyol compound (a3) is at least one of a polyester polyol and a polycarbonate polyol.   The active energy ray-curable resin composition according to any one of claims 1 to 7, wherein the metal salt (X) is a fatty acid metal salt having 8 to 10 carbon atoms. A method for producing an active energy ray-curable resin composition containing the following (A), (B) and (X), and containing a hydroxyl group-containing monomer (b1) as the following (B): A compound (A) is obtained by reacting a polyvalent isocyanate compound (a1), a hydroxyl group-containing (meth) acrylate compound (a2), and a polyol compound (a3) in the presence of a metal salt (X). A process for producing an active energy ray-curable resin composition characterized by the above.
(A) Urethane (meth) acrylate-based compound.
(B) An ethylenically unsaturated monomer excluding (A) above.
(X) Metal salt. The metal salt (X) is blended so as to be 5 × 10 ⁻³ to 1 × 10 ⁻¹ parts by weight with respect to 100 parts by weight of the urethane (meth) acrylate compound (A) obtained above. A method for producing an active energy ray-curable resin composition according to claim 9.