JP2023094702A - Active energy ray-curable adhesive composition and adhesive - Google Patents

Abstract

To provide an active energy ray-curable adhesive composition having good adhesive force.SOLUTION: The active energy ray-curable adhesive composition contains: a urethane (meth)acrylate-based compound (A) being a reaction product of a polyester polyol (a1), a polyvalent isocyanate (a2), and a hydroxyl group-containing (meth)acrylate (a3-1) and/or a monool (a3-2); and an ethylenically unsaturated monomer (B). The glass transition temperature of a cured product (I) of the active energy ray-curable adhesive composition is higher than 20°C and 85°C or lower.SELECTED DRAWING: None

Description

The present invention relates to an active energy ray-curable pressure-sensitive adhesive composition and a pressure-sensitive adhesive, and more particularly, an active energy ray containing a urethane (meth)acrylate compound and having good adhesive strength when used as a pressure-sensitive adhesive. The present invention relates to a curable pressure-sensitive adhesive composition and a pressure-sensitive adhesive obtained by curing such an active energy ray-curable pressure-sensitive adhesive composition.

Conventionally, urethane (meth)acrylate compounds obtained by reacting diol compounds such as polyester diols and polyether diols, diisocyanate compounds such as isophorone diisocyanate and diphenylmethane diisocyanate, and hydroxyl group-containing (meth)acrylate compounds such as hydroxyethyl acrylate, It is known as an active energy ray-curable adhesive composition, and is used for applications such as adhesives, paints, coating agents, and adhesives.

However, many urethane (meth)acrylate compounds are adhesives using organic solvents, which has been a problem. 1-4).

JP-A-5-43636 JP-A-5-262848 JP-A-10-330453 JP 2010-100711 A

However, in the active energy ray-curable pressure-sensitive adhesive composition containing the urethane (meth)acrylate compound in these Patent Documents 1 to 4, the pressure-sensitive adhesive obtained by preparing the pressure-sensitive adhesive without using a solvent is inferior in adhesive strength. Further improvement has been demanded.

Under such circumstances, an object of the present invention is to provide an active energy ray-curable pressure-sensitive adhesive composition capable of obtaining a pressure-sensitive adhesive having good adhesive strength, and a pressure-sensitive adhesive obtained by curing the same. and

However, as a result of extensive research to solve the above problems, the present inventors have found an active energy ray-curable adhesive containing a urethane (meth)acrylate compound (A) and an ethylenically unsaturated monomer (B) In the agent composition, by setting the glass transition temperature of the cured product (I) when preparing the cured product (I) from the active energy ray-curable adhesive composition to a temperature range higher than usual, the adhesive and The present inventors have completed the present invention by finding that the adhesive strength is good when the adhesive is applied.

That is, the gist of the present invention is a urethane ( meth) acrylate compound (A),
An active energy ray-curable pressure-sensitive adhesive composition containing an ethylenically unsaturated monomer (B),
The active energy ray-curable pressure-sensitive adhesive composition is characterized in that the cured product (I) of the active energy ray-curable pressure-sensitive adhesive composition has a glass transition temperature of more than 20°C and 85°C or less.

Another gist of the present invention is a pressure-sensitive adhesive obtained by curing the active energy ray-curable pressure-sensitive adhesive composition.

ADVANTAGE OF THE INVENTION The active-energy-ray-curable adhesive composition of this invention has favorable adhesive force, when an adhesive is prepared. The active energy ray-curable pressure-sensitive adhesive composition of the present invention can be used, for example, in the form of pressure-sensitive adhesive tapes, pressure-sensitive adhesive sheets, pressure-sensitive adhesive films, and the like, and is used for electronic members, automobiles, housing/building materials, medical applications, and the like. be able to. In addition, it can be applied to various uses such as surface protection, curing, anti-slip, and electrical insulation.

In particular, the active energy ray-curable pressure-sensitive adhesive composition of the present invention can be widely used as a surface protective sheet for metal plates, glass plates, plastic plates, resin-coated surfaces, and the like. In addition, the active energy ray-curable pressure-sensitive adhesive composition of the present invention can also be used as a sheet (tape) for fixing electronic parts, a seal (tape) for labeling electronic parts, and a lamination resin for optical displays or touch centers. is. For example, it can be suitably used for various applications such as bonding an optical display panel and a touch panel, bonding an optical display panel and an optical display panel, and bonding an optical display panel and a parallax barrier.

Although the present invention will be described in detail below, these show examples of preferred embodiments, and the present invention is not limited to these.
In the present invention, "(meth)acrylic" means acrylic or methacrylic, "(meth)acryloyl" means acryloyl or methacryloyl, and "(meth)acrylate" means acrylate or methacrylate. .

[Active energy ray-curable adhesive composition]
The active energy ray-curable pressure-sensitive adhesive composition of the present invention contains a urethane (meth)acrylate compound (A) and an ethylenically unsaturated monomer (B), and if necessary, a photopolymerization initiator ( C).
Each component will be described below.

<Urethane (meth)acrylate compound (A)>
The urethane (meth)acrylate compound (A) in the present invention is polyester polyol (a1), polyvalent isocyanate (a2) and hydroxyl group-containing (meth)acrylate (a3-1) and/or monool (a3-2). It is a reaction product.

[Polyester polyol (a1)]
Examples of the above polyester-based polyols include condensation polymers of polyhydric alcohols and polycarboxylic acids; ring-opening polymers of cyclic esters (lactones); polyhydric alcohols, polycarboxylic acids, and cyclic esters. and the like.

Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,4-tetramethylenediol, 1,3-tetramethylenediol, 2-methyl-1,3-tri methylenediol, 1,5-pentamethylenediol, neopentyl glycol, 1,6-hexamethylenediol, 3-methyl-1,5-pentamethylenediol, 2,4-diethyl-1,5-pentamethylenediol, Examples include glycerin, trimethylolpropane, trimethylolethane, cyclohexanediols (1,4-cyclohexanediol, etc.), bisphenols (bisphenol A, etc.), sugar alcohols (xylitol, sorbitol, etc.).

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; Examples include quantified products and hydrogenated dimer acids obtained by hydrogenating them.
As the thermal dimer of unsaturated fatty acid and the hydrogenated dimer acid obtained by hydrogenation thereof, specifically, a dimer mainly composed of unsaturated fatty acids having 10 to 24 carbon atoms, preferably around 18 carbon atoms For example, it is a dicarboxylic acid derived from unsaturated fatty acids such as oleic acids, linoleic acids, linolenic acids, and erucic acids. Major dimer acids include those having 36 and 44 carbon atoms.

In the present invention, the number average molecular weight of the polyester polyol (a1) is preferably 500 to 5000, more preferably 800 to 4000, particularly preferably 800 to 4000, in terms of handleability and adhesive strength when the adhesive is prepared. 1000-3500, particularly preferably 1500-3300.
If the number average molecular weight is too small, the pressure-sensitive adhesive strength tends to be low.

In the present invention, the number average molecular weight is obtained from the hydroxyl value, and the hydroxyl value is measured according to JIS K1557-1 (2007) by a method using an acetylating reagent or a phthalating reagent.

The polyester polyol (a1) may be used alone or in combination of two or more.

[Polyvalent isocyanate (a2)]
The polyvalent isocyanate (a2) used in the present invention is an isocyanate having two or more isocyanate groups, preferably two or three isocyanate groups. Examples of polyvalent isocyanates include aliphatic polyvalent isocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and lysine triisocyanate; hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, and norbornene diisocyanate. Alicyclic polyvalent isocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylene diisocyanate, naphthalene diisocyanate and other aromatic polyvalent isocyanates and polyvalent isocyanates such as ; and polymeric compounds such as trimer compounds of the polyvalent isocyanates. Allophanate-type polyisocyanates, burette-type polyisocyanates, and the like are also included.
Polyisocyanate (a2) may be used alone or in combination of two or more.

Among these, aliphatic polyvalent isocyanates and alicyclic polyvalent isocyanates are preferable from the point of view of adhesive physical properties when preparing adhesives, and isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated xylene diisocyanate. , hexamethylene diisocyanate, and isophorone diisocyanate is particularly preferred.

[Hydroxyl-containing (meth)acrylate (a3-1)]
The hydroxyl group-containing (meth)acrylate (a3-1) used in the present invention is a (meth)acrylate containing one or more hydroxyl groups, and among the hydroxyl group-containing (meth)acrylates, the above polyester polyol (a1) Excludes items that fall under
Examples of hydroxyl group-containing (meth)acrylates (a3-1) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Acrylate, hydroxyalkyl (meth)acrylate such as 6-hydroxyhexyl (meth)acrylate, 2-hydroxyethyl acryloyl 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) acrylate, 2-hydroxy-3-(meth) acryloyloxypropyl ( Hydroxyl group-containing (meth)acrylate containing one ethylenically unsaturated group such as meth)acrylate; two ethylenically unsaturated groups such as glycerin di(meth)acrylate and 2-hydroxy-3-acryloyl-oxypropyl methacrylate Containing hydroxyl group-containing (meth)acrylate; pentaerythritol tri(meth)acrylate, caprolactone-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, caprolactone-modified di Examples include hydroxyl group-containing (meth)acrylates containing three or more ethylenically unsaturated groups, such as pentaerythritol penta(meth)acrylate and ethylene oxide-modified dipentaerythritol penta(meth)acrylate.
The hydroxyl group-containing (meth)acrylates (a3-1) may be used alone or in combination of two or more.

Among these, hydroxyl group-containing (meth)acrylates containing one ethylenically unsaturated group are preferred, and hydroxyalkyl (meth)acrylates are more preferably used, particularly in terms of adhesive physical properties when the pressure-sensitive adhesive is prepared. Hydroxyalkyl (meth)acrylates having alkyl groups of 1 to 4 carbon atoms, particularly 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate are particularly preferred.

[Monool (a3-2)”
The above monool (a3-2) may be a compound containing one hydroxyl group, preferably having 1 or more carbon atoms, more preferably 2 to 20 carbon atoms.

Examples of the monool (a3-2) include aliphatic monools, aromatic monools, alicyclic monools, polyoxyalkylene glycol monoalkyl ethers, and the like. The above monool (a3-2) may be used alone or in combination of two or more.

Examples of the aliphatic monools include methanol, ethanol, 1-propanol, 2-propanol (isopropyl alcohol), 1-butanol, 2-butanol, 1-pentanol, 1-hexanol, 2-methyl-1-pentane. Tanol, 4-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 1-octanol, 2-octanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-hexa linear saturated aliphatic monools such as decanol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-hexacosanol, 1-heptatricontanol, 2-octyldodecanol; Linear unsaturated aliphatic monools such as 1-oleyl alcohol, 2-ethylhexanol, 2-hexyldecanol, isooctadecanol, 3,5-dimethyl-1-hexanol, 2,2,4-trimethyl-1-pen branched chain saturated aliphatic monools such as tanol and 2,6-dimethyl-4-heptanol;

Examples of the aromatic monool include phenol, cresol, benzyl alcohol and the like.

Examples of the alicyclic monool include cyclohexanol and methylcyclohexanol.

Examples of the polyoxyalkylene glycol monoalkyl ether include reaction products of the above aliphatic monool and polyoxypropylene glycol. Specifically, polyoxypropylene methyl ether, polyoxypropylene ethyl ether, polyoxypropylene Propylene butyl ether, polyoxypropylene-2-ethylhexyl ether, polyoxypropylene oleyl ether, polyoxypropylene-2-octyl dodecaether and the like.

The weight average molecular weight of the monool (a3-2) is usually 30 to 5,000, preferably 40 to 4,000, more preferably 45 to 1,000, particularly preferably 50 to 500. If the weight-average molecular weight of the monool (a3-2) is too large, the urethane (meth)acrylate compound (B) and the acrylic resin (A) obtained will be difficult to mix uniformly, and the adhesive will not adhere to the workpiece. Residue tends to occur more easily. On the other hand, when the weight average molecular weight of the monool (b2) is too small, the pressure-sensitive adhesive layer tends to crack easily after irradiation with active energy rays.

Among these monools (a3-2), the polarity of the urethane (meth)acrylate compound (B) can be lowered, and from the viewpoint of excellent compatibility, it has a linear alkyl chain with 2 or more carbon atoms. A monool is preferable, more preferably an aliphatic monool having a linear alkyl group with 2 or more carbon atoms, and particularly preferably a linear unsaturated aliphatic monool having a linear alkyl group with 2 or more carbon atoms. 2-propanol (isopropyl alcohol), 1-decanol and 1-octanol are particularly preferred.

[Production of urethane (meth)acrylate compound (A)]
The urethane (meth)acrylate compound (A) in the present invention is obtained by reacting the above components (a1) to (a3-1) and/or (a3-2). The manufacturing method is not particularly limited, and it can be manufactured according to a known method. Specifically, it can be produced, for example, as follows.

For example, (i) the above polyester polyol (a1), polyvalent isocyanate (a2), hydroxyl group-containing (meth)acrylate (a3-1) and/or monool (a3-2) are collectively or separately charged into a reactor. (ii) a terminal isocyanate group-containing reaction product obtained by pre-reacting the polyester polyol (a1) and the polyvalent isocyanate (a2), a hydroxyl group-containing (meth)acrylate (a3-1) and / or A method of reacting the monool (a3-2), (iii) obtained by pre-reacting the polyvalent isocyanate (a2) with the hydroxyl group-containing (meth)acrylate (a3-1) and/or the monool (a3-2). and a method of reacting the polyester polyol (a1) with the reaction product obtained, and the like, but the method (ii) is preferable from the viewpoint of stability of the reaction, reduction of by-products, and the like.

Regarding the method (ii) above, the polyester polyol (a1) and the polyvalent isocyanate (a2) can be reacted using known reaction means. At that time, for example, the molar ratio when there are two isocyanate groups in the polyvalent isocyanate (a2) and two hydroxyl groups in the polyester polyol (a1) is usually 2n: (2n-1) (n is 1 It is preferable to set it to about an integer above), so that the isocyanate group remains and the addition reaction with the hydroxyl group-containing (meth) acrylate (a3-1) and / or monool (a3-2) is facilitated. be able to.

n in the above molar ratio is preferably 1 or more and 10 or less. The lower limit of n is more preferably 1.5. The upper limit of n is more preferably 9. If n is too small, the pressure-sensitive adhesive strength tends to be low when the pressure-sensitive adhesive is prepared. There is

The reaction molar ratio of the terminal isocyanate group-containing reaction product, the hydroxyl group-containing (meth)acrylate (a3-1), and the total amount of the monool (a3-2) is, for example, the isocyanate group content of the terminal isocyanate group-containing reaction product. When the number is two and the number of hydroxyl groups in the hydroxyl group-containing (meth)acrylate (a3-1) is one, the terminal isocyanate group-containing reaction product is usually: a hydroxyl group-containing (meth)acrylate compound (a3- 1) has a molar ratio of about 1:2, the number of isocyanate groups in the terminal isocyanate group-containing reaction product is 3, and the number of hydroxyl groups in the hydroxyl group-containing (meth)acrylate (a3-1) is 1. In this case, the molar ratio of the terminal isocyanate group-containing reaction product to the hydroxyl group-containing (meth)acrylate compound (a3-1) is usually about 1:3.

In the addition reaction between this terminal isocyanate group-containing reaction product and the hydroxyl group-containing (meth)acrylate (a3-1) and/or monool (a3-2), the residual isocyanate group content in the reaction system is usually 0.5. It is preferable to terminate the reaction when the content becomes 1% by weight or less, whereby the urethane (meth)acrylate compound (A) of the present invention can be obtained.

In the present invention, a reaction of a polyester polyol (a1) and a polyvalent isocyanate (a2), further, a terminal isocyanate group-containing reaction product obtained by the reaction and a hydroxyl group-containing (meth)acrylate (a3-1) and / or In the reaction with monool (a3-2), it is also preferable to use a catalyst for the purpose of promoting the reaction.

Examples of such catalysts include organometallic compounds such as dibutyltin dilaurate, trimethyltin hydroxide, tetra-n-butyltin, zinc octylate, zinc stearate, zirconium 2-ethylhexanoate, tin octylate, and cobalt naphthenate. , metal salts such as stannous chloride and stannic chloride; inorganic bismuth compounds such as bismuth nitrate, bismuth bromide, bismuth iodide and bismuth sulfide; organic bismuth compounds such as dibutyl bismuth dilaurate and dioctyl bismuth dilaurate; 2-ethyl Bismuth hexanoate, bismuth naphthenate, bismuth isodecanoate, bismuth neodecanoate, bismuth laurate, bismuth maleate, bismuth stearate, bismuth oleate, bismuth linoleate, bismuth acetate, bismuth Bismuth-based catalysts such as bismuth salts of organic acids such as ribis neodecanoate and bismuth disalicylate, triethylamine, benzyldiethylamine, 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4 ,0]undecene, N,N,N',N'-tetramethyl-1,3-butanediamine and N-ethylmorpholine. Among these, dibutyltin dilaurate and 1,8-diazabicyclo[5,4,0]undecene are preferred. These may be used individually by 1 type, and can also be used in combination of 2 or more types.

Further, the reaction of the polyester polyol (a1) and the polyvalent isocyanate (a2), further, the terminal isocyanate group-containing reaction product obtained by the reaction and the hydroxyl group-containing (meth) acrylate (a3-1) and / or monol In the reaction with (a3-2), an organic solvent having no functional group reactive with an isocyanate group, such as esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone; toluene; Organic solvents such as aromatics such as xylene can be used.

The reaction temperature is generally 30 to 90°C, preferably 40 to 80°C, and the reaction time is generally 2 to 12 hours, preferably 3 to 10 hours.

Thus, the urethane (meth)acrylate compound (A) is obtained. The active energy ray-curable pressure-sensitive adhesive composition of the present invention may contain one type of urethane (meth)acrylate compound (A) alone, or may contain two or more types.

In the present invention, it is important that the urethane (meth)acrylate compound (A) obtained above have a number average molecular weight of 500 to 30,000, preferably 700 to 28,000, and particularly preferably 800 to 23,000. If the number average molecular weight is too small, the pressure-sensitive adhesive strength tends to be low.

The weight average molecular weight of the urethane (meth)acrylate compound (A) is preferably 1,000 to 100,000, more preferably 4,000 to 90,000, and particularly preferably 7,000 to 80,000. If the weight-average molecular weight is too small, the pressure-sensitive adhesive strength tends to be low.

Furthermore, the degree of dispersion (weight average molecular weight/number average molecular weight) of the urethane (meth)acrylate compound (A) is preferably 15 or less, more preferably 10 or less, particularly preferably 7 or less, and even more preferably 5. It is below. If the degree of dispersion is too high, the viscosity tends to increase, resulting in reduced handling properties and insufficient adhesion. In addition, the lower limit of the degree of dispersion is usually 1.1 in view of manufacturing limitations.

The above number-average molecular weight and weight-average molecular weight are the number-average molecular weight and weight-average molecular weight in terms of standard polystyrene molecular weight. 450 x 1, ACQUITY APC XT 200 x 1, ACQUITY APC XT 45 x 2 in series. At that time, when the sample to be measured contains an ethylenically unsaturated monomer (B) described later, the number average molecular weight and weight average molecular weight are determined by excluding the ethylenically unsaturated monomer (B). Further, the dispersity is obtained from the weight average molecular weight and the number average molecular weight.

<Ethylenically unsaturated monomer (B)>
The ethylenically unsaturated monomer (B) used in the present invention may have one or more ethylenically unsaturated groups in one molecule, and examples thereof include monofunctional monomers, bifunctional monomers, and trifunctional or higher monomers. be done. The active energy ray-curable pressure-sensitive adhesive composition of the present invention may contain one type of ethylenically unsaturated monomer (B) alone, or may contain two or more types.

Examples of the monofunctional monomers include styrene, vinyltoluene, chlorostyrene, α-methylstyrene, methyl (meth)acrylate, ethyl (meth)acrylate, acrylonitrile, vinyl acetate, 2-hydroxyethyl (meth)acrylate, 2- Hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-phenoxy-2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3 -chloro-2-hydroxypropyl (meth)acrylate, glycerin mono(meth)acrylate, glycidyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, tricyclodecanyl (meth)acrylate Acrylate, dicyclopentenyl (meth)acrylate, n-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, benzyl (meth) acrylate, phenol ethylene oxide-modified (meth) acrylate, nonylphenol propylene oxide-modified (meth) acrylate, 2-(meth) acryloyloxy- Half ester (meth)acrylate of phthalic acid derivatives such as 2-hydroxypropyl phthalate, furfuryl (meth)acrylate, carbitol (meth)acrylate, benzyl (meth)acrylate, butoxyethyl (meth)acrylate, allyl (meth)acrylate, acryloylmorpholine, 2-hydroxyethylacrylamide, N-methylol(meth)acrylamide, N-vinylpyrrolidone, 2-vinylpyridine, 2-(meth)acryloyloxyethyl acid phosphate monoester and the like.

In addition to the above, examples of the monofunctional monomers include Michael adducts of acrylic acid and 2-acryloyloxyethyldicarboxylic acid monoesters. Michael adducts of acrylic acid include acrylic acid dimer, methacrylic acid dimer, acrylic acid trimer, methacrylic acid trimer, acrylic acid tetramer, methacrylic acid tetramer, and the like. In addition, 2-acryloyloxyethyl dicarboxylic acid monoesters, which are carboxylic acids having specific substituents, include, for example, 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, 2-acryloyloxyethyl Phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, 2-methacryloyloxyethyl hexahydrophthalic acid monoester and the like can be mentioned. Furthermore, oligoester acrylates are also mentioned.

Examples of the bifunctional monomer include 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, di Propylene 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, glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate, ethylene Glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, phthalate diglycidyl ester di(meth)acrylate, hydroxypivalic acid-modified neopentyl glycol di(meth)acrylate, isocyanuric acid ethylene oxide-modified di(meth)acrylate acrylates, 2-(meth)acryloyloxyethyl acid phosphate diesters, and the like.

Examples of the trifunctional or higher monomer include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa( meth)acrylate, tri(meth)acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly(meth)acrylate, isocyanuric acid ethylene oxide-modified triacrylate, ethylene oxide-modified dipentaerythritol penta(meth)acrylate, ethylene oxide-modified dipenta Erythritol hexa(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tetra(meth)acrylate, succinic acid-modified pentaerythritol tri(meth)acrylate and the like.

The ethylenically unsaturated monomer (B) is, for example, an ethylenically unsaturated monomer (B1) having a glass transition temperature of 0° C. or higher and 130° C. or lower (hereinafter referred to as “ethylenically unsaturated monomer (B1)”), and Ethylenically unsaturated monomer (B2) having a glass transition temperature of −60° C. or more and less than 0° C. (hereinafter referred to as “ethylenically unsaturated monomer (B2)”), etc. These may be one or two or more. They may be used together.

In the present invention, the glass transition temperature of the ethylenically unsaturated monomer (B) is the glass transition temperature of a homopolymer prepared using the ethylenically unsaturated monomer (B). (POLYM HANDBOOK Fourth Edition), John Wiley & Sons, Inc. (1999) and "Polymer Data Handbook" edited by the Society of Polymer Science (1986) can be used. For the glass transition temperature (Tg) of homopolymers not described in these publications, values described in other documents or product catalogs or values actually measured by producing homopolymers can be used.

[Ethylenically unsaturated monomer (B1)]
The ethylenically unsaturated monomer (B1) has a glass transition temperature of 0° C. or higher and 130° C. or lower, preferably 10° C. or higher and 120° C. or lower, more preferably 20° C. or higher and 100° C. or lower. If the upper limit of the glass transition temperature of the ethylenically unsaturated monomer (B1) is too high, the adhesive strength of the obtained adhesive tends to decrease.

Examples of the ethylenically unsaturated monomer (B1) include styrene monomers such as styrene (100°C); methyl (meth)acrylate (Tga = 8°C, Tgm = 105°C), ethyl methacrylate (Tgm = 65°C). , n-butyl methacrylate (Tg = 20°C), isobutyl methacrylate (Tg = 48°C), t-butyl (meth)acrylate (Tg = 41°C, Tg = 107°C), n-stearyl (meth)acrylate (Tg = 30°C, Tgm = 38°C); hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl methacrylate (Tgm = 55°C) and 2-hydroxypropyl methacrylate (Tgm = 26°C); dimethylamino Amino group-containing (meth)acrylates such as ethyl methacrylate (Tgm = 18°C) and diethylaminoethyl methacrylate (Tgm = 16-24°C); °C), cyclohexyl (meth)acrylate (Tga = 15 °C, Tgm = 66 °C), 3,3,5-trimethylcyclohexyl acrylate (Tga = 52 °C); benzyl aromatic (meth)acrylates such as (meth)acrylate (Tga = 6°C, Tgm = 54°C); tetrahydrofurfuryl methacrylate (Tgm = 60°C), glycidyl (meth)acrylate (Tga = 60°C, Tgm = 46°C); ), (3-ethyloxetan-3-yl)methyl methacrylate (Tgm = 2°C), heterocyclic (meth)acrylates such as cyclic trimethylolpropane formal acrylate (Tga = 27°C); Examples include monomers, and amide monomers such as vinyl acetate (Tg=29° C.); hydroxyethylacrylamide (Tg=98° C.) and diethylacrylamide (Tg=81° C.). These may be used alone or in combination of two or more. Among them, alicyclic (meth)acrylates and heterocyclic (meth)acrylates are preferred, and isobornyl acrylate and cyclic trimethylolpropane formal acrylate are particularly preferred. The numerical value in parentheses after the compound name indicates the glass transition temperature. "Tga" indicates the glass transition temperature of acrylate, and "Tgm" indicates the glass transition temperature of methacrylate.

The content of the ethylenically unsaturated monomer (B1) is preferably 10 to 100 parts by weight, more preferably 20 to 80 parts by weight, relative to 100 parts by weight of the urethane (meth)acrylate compound (A). and particularly preferably 30 to 60 parts by weight. When the content of the ethylenically unsaturated monomer (B1) is within the above range, the viscosity tends to be low.

[Ethylenically unsaturated monomer (B2)]
The ethylenically unsaturated monomer (B2) has a glass transition temperature of -60°C or higher and lower than 0°C, preferably -50°C or higher and -5°C or lower, more preferably -30°C or higher and -10°C or lower. be. If the lower limit of the glass transition temperature of the ethylenically unsaturated monomer (B2) is too low, the viscosity tends to increase.

Examples of the ethylenically unsaturated monomer (B2) include n-butyl acrylate (Tga = -56°C), isobutyl acrylate (Tga = -26°C), 2-ethylhexyl methacrylate (Tgm = -10°C), isononyl acrylate (Tga = -58°C), n-lauryl acrylate (Tga = -23°C), nonyl acrylate (Tga = -37°C), isostearyl acrylate (Tga = -18°C), isodecyl acrylate (Tga = -62°C), alkyl (meth)acrylates such as isodecyl methacrylate (Tgm = -41°C); 2-hydroxyethyl acrylate (Tga = -15°C), 2-hydroxypropyl acrylate (Tga = -7°C), 4 - hydroxyl group-containing (meth)acrylates such as hydroxybutyl acrylate (Tga = -32°C); aromatic (meth)acrylates such as phenoxyethyl acrylate (Tga = -22°C); tetrahydrofurfuryl acrylate (Tga = -12°C) , (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl acrylate (Tga = -7°C), 4-hydroxybutyl acrylate glycidyl ether (Tga = -59°C) and other heterocyclic meth)acrylate; 2-methoxyethyl (meth)acrylate (Tga = -50°C, Tgm = -2°C), alkoxy group-containing (meth)acrylate such as 2-ethoxyethyl methacrylate (Tgm = -31°C) ( meth)acrylate monomers. These may be used alone or in combination of two or more. Among them, alkyl (meth)acrylates, aromatic (meth)acrylates and heterocyclic (meth)acrylates are preferable, n-butyl acrylate, phenoxyethyl acrylate and tetrahydrofurfuryl acrylate are more preferable, and phenoxyethyl acrylate and tetrahydrofurfuryl are more preferable. Acrylates are particularly preferred, and tetrahydrofurfuryl acrylate is especially preferred. The numerical value in parentheses after the compound name indicates the glass transition temperature. "Tga" indicates the glass transition temperature of acrylate, and "Tgm" indicates the glass transition temperature of methacrylate.

The content of the ethylenically unsaturated monomer (B2) is preferably 10 to 100 parts by weight, more preferably 20 to 80 parts by weight, with respect to 100 parts by weight of the urethane (meth)acrylate compound (A). and particularly preferably 30 to 60 parts by weight. When the content of the ethylenically unsaturated monomer (B2) is within the above range, the viscosity tends to be low.

When the ethylenically unsaturated monomer (B1) and the ethylenically unsaturated monomer (B2) are used in combination, the content ratio (B1/B2) is preferably 80/20 to 30/70 by weight, and is preferably 70/ It is more preferably 30 to 35/65, particularly preferably 65/35 to 40/60. When the content ratio of the ethylenically unsaturated monomer (B1) and the ethylenically unsaturated monomer (B2) is within the above range, the viscosity tends to be low and the adhesion to various members tends to be excellent.

The ethylenically unsaturated monomer (B) contains an ethylenically unsaturated monomer (B3) other than the ethylenically unsaturated monomer (B1) and the ethylenically unsaturated monomer (B2) within a range that does not impede the effects of the present invention ( For example, 10% by weight or less of the ethylenically unsaturated monomer (B)), but in the present invention, the ethylenically unsaturated monomer (B) is composed of the ethylenically unsaturated monomer (B1) and the ethylenically unsaturated monomer (B1). It is preferably composed only of the monomer (B2).

Examples of ethylenically unsaturated monomers (B3) include 2-ethylhexyl acrylate (Tga = -70°C), 4-hydroxybutyl acrylate (Tga = -80°C), ethyl carbitol acrylate (Tga = -67°C), Ethoxydiethylene glycol acrylate (Tga = -70°C), isodecyl acrylate (Tg = -62°C), lauryl methacrylate (Tgm = -65°C), octyl acrylate (Tga = -65°C), iso-octyl acrylate (Tga = - 70°C), tetradecyl methacrylate (Tg = -72°C), acryloylmorpholine (Tg = 145°C), isopropylacrylamide (Tg = 134°C), dimethylaminopropylacrylamide (Tg = 134°C), 1-adamantyl methacrylate (Tgm = 250°C), 1-adamantyl acrylate (Tga = 153°C), acrylamide (Tg = 153°C), and the like. These may be used alone or in combination of two or more. The numerical value in parentheses after the compound name indicates the glass transition temperature. "Tga" indicates the glass transition temperature of acrylate, and "Tgm" indicates the glass transition temperature of methacrylate.

The content of the ethylenically unsaturated monomer (B) is preferably 20 to 150 parts by weight, more preferably 50 to 120 parts by weight, based on 100 parts by weight of the urethane (meth)acrylate compound (A). and particularly preferably 70 to 100 parts by weight. When the content of the ethylenically unsaturated monomer (B) is within the above range, the viscosity tends to be low and the adhesion to various members tends to be excellent.

<Photoinitiator (C)>
The active energy ray-curable pressure-sensitive adhesive composition of the present invention preferably further contains a photopolymerization initiator (C) in order to perform curing with active energy rays more efficiently.

Examples of the photopolymerization initiator (C) include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 4-(2-hydroxyethoxy)-phenyl-(2 -hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenylketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propan-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-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one , 2,2-dimethoxy-1,2-diphenylethan-1-one, phenylglyoxylic acid methyl ester, and other acetophenones; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, etc. Class; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenylsulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 2 ,4,6-trimethylbenzophenone, 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzenemethanaminium bromide, (4-benzoylbenzyl)trimethylammonium chloride benzophenones such as; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-(3-dimethylamino-2-hydroxy) Thioxanthones such as -3,4-dimethyl-9H-thioxanthon-9-one mesochloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4 -acylphosphine oxides such as trimethyl-pentylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; 1-[4-(phenylthio)phenyl]-1,2-octanedione2 -(O-benzoyloxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime) and other oxime esters. In addition, these photoinitiators (C) may be used individually by 1 type, and 2 or more types may be used together.

Among these, benzyl dimethyl ketal, 1-hydroxycyclohexylphenyl ketone, benzoin isopropyl ether, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1- Phenylpropan-1-one is preferably used.

The content of the photopolymerization initiator (C) is 0.1 to 40 parts by weight with respect to a total of 100 parts by weight of the urethane (meth)acrylate compound (A) and the ethylenically unsaturated monomer (B). is preferred, more preferably 0.5 to 20 parts by weight, and particularly preferably 1 to 10 parts by weight. When the content of the photopolymerization initiator (C) is within the above range, curing by active energy rays can be performed more efficiently. In addition, when the content of the photopolymerization initiator (C) is too large, there is a tendency that the solution stability is deteriorated, such as precipitation during coating, and problems such as embrittlement and coloration occur.

Further, as an auxiliary agent for the photopolymerization initiator (C), triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler's ketone), 4,4'-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, ethyl 4-dimethylaminobenzoate, (n-butoxy)ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone, 2, It is also possible to use 4-diisopropylthioxanthone or the like in combination.

Regarding the method of mixing the urethane (meth)acrylate compound (A), the ethylenically unsaturated monomer (B), and the photopolymerization initiator (C) in producing the active energy ray-curable composition obtained in the present invention, are not particularly limited, and can be mixed by various methods. For example, each component can be mixed together, or an arbitrary component can be mixed first, and then the remaining components can be mixed.

Thus, the active energy ray-curable pressure-sensitive adhesive composition of the present invention is obtained.
Additives such as a surface conditioner, a leveling agent, and a polymerization inhibitor may be added as necessary. When the active energy ray-curable pressure-sensitive adhesive composition of the present invention contains an additive, the content of the additive is usually 20% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less. be.

The surface conditioner is not particularly limited, and examples thereof include alkyd resins.
Such an alkyd resin has the effect of imparting film-forming properties during coating and the effect of increasing adhesion to the surface of a metal thin film.

As the leveling agent, known general leveling agents can be used as long as they have the action of imparting the wettability of the coating liquid to the substrate and the action of lowering the surface tension. A resin, an alkyl-modified resin, or the like can be used. These may be used alone or in combination of two or more.

Examples of polymerization inhibitors include p-benzoquinone, naphthoquinone, tolquinone, 2,5-diphenyl-p-benzoquinone, hydroquinone, 2,5-di-t-butylhydroquinone, methylhydroquinone, methoxyphenol, 2,6-di -t-butyl-p-cresol, mono-t-butylhydroquinone, pt-butylcatechol and the like.
Among them, methoxyphenol and 2,6-di-t-butyl-p-cresol are preferred. These may be used alone or in combination of two or more.

The active energy ray-curable pressure-sensitive adhesive composition of the present invention is cured by irradiating it with an active energy ray after it is applied onto various substrates and dried.

The method of applying the active energy ray-curable pressure-sensitive adhesive composition is not particularly limited, and examples thereof include spray, shower, dipping, roll, spin, curtain, flow, slit, die, gravure, comma, and dispenser. , screen printing, inkjet printing and the like.

Examples of substrates to which the active energy ray-curable pressure-sensitive adhesive composition obtained in the present invention is applied include polyolefin resins, polyester resins, polycarbonate resins, acrylonitrile-butadiene-styrene copolymers (ABS), and polystyrene-based resins. Resins, polyamide resins, etc. and their molded products (films, sheets, cups, etc.), metal substrates (metal deposition layers, metal plates (copper, stainless steel (SUS304, SUSBA, etc.), aluminum, zinc, magnesium, etc.)) , glass and the like, and composite substrates thereof.

The above coating can usually be carried out without a solvent, but if necessary, an organic solvent may be blended to adjust the viscosity. Examples of such organic solvents 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. aromatics such as propylene glycol monomethyl ether; glycol ethers such as propylene glycol monomethyl ether; acetic esters such as methyl acetate, ethyl acetate and butyl acetate; These organic solvents may be used alone or in combination of two or more.

Moreover, the method of heating the said active-energy-ray-curable adhesive composition, and coating by the said method, etc., after reducing a viscosity is mentioned.

Examples of such active energy rays include light rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays and infrared rays; electromagnetic waves such as X rays and γ rays; electron beams, proton rays, neutron rays and the like. Curing by ultraviolet irradiation is advantageous in terms of curing speed, availability of irradiation equipment, price, and the like. In addition, when electron beam irradiation is performed, curing can be performed without using the photopolymerization initiator (C).

For example, as a method of curing by ultraviolet irradiation, a device that emits light in a wavelength range of 150 to 450 nm, such as a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a chemical lamp, an electrodeless discharge lamp, and an LED. and the like to irradiate about 30 to 3,000 mJ/cm ² .
After the ultraviolet irradiation, heating may be performed as necessary to complete curing.

The thickness of the cured coating film is usually 1 to 300 μm, preferably 2 to 250 μm, more preferably 5 to 200 μm, in consideration of light transmission so that the photopolymerization initiator (C) reacts uniformly.

<Cured product (I) of active energy ray-curable pressure-sensitive adhesive composition>
As described above, the active energy ray-curable pressure-sensitive adhesive composition of the present invention is cured by irradiation with an active energy ray to form a cured product (I).
In the present invention, the glass transition temperature of the cured product (I) of the active energy ray-curable pressure-sensitive adhesive composition is more than 20°C and 85°C or less, preferably 21 to 80°C, more preferably 23 to 70. °C, particularly preferably 25 to 60°C. When the glass transition temperature (Tg) is out of the above range, the pressure-sensitive adhesive strength tends to decrease when the pressure-sensitive adhesive is prepared.
Methods for producing a cured product (I) having such a Tg exceeding 20° C. include (1) a method of adjusting the Tg by changing the molecular weight of urethane (meth)acrylate; A method of adjusting the Tg by changing, and the like.

The method for measuring the glass transition temperature (Tg) is as follows.
Apply the active energy ray-curable adhesive composition to an easy-adhesion treated polyethylene terephthalate (PET) film (thickness: 125 μm) using an applicator so that the film thickness after curing is 100 μm. Graphics Co., Ltd., "conveyor type tabletop irradiation device") under the conditions of 80 W / cm (high pressure mercury lamp) × 18 cmH × 1.9 m / min × 3 passes (accumulated irradiation amount 2,400 mJ / cm ² ). A pressure-sensitive adhesive sheet for measuring pressure-sensitive adhesive strength is prepared by irradiation and curing. A test piece having a length of 20 mm and a width of 3 mm is cut out from this adhesive sheet for measuring adhesive force. For such a test piece, using the tension mode of the dynamic viscoelasticity measuring device "DVA-225" manufactured by IT Keisoku Co., Ltd., the frequency is 10 Hz, the temperature increase rate is 3 ° C./min, and the strain is 0.1%. . The ratio (tan δ) of the imaginary part (loss elastic modulus) to the real part (storage elastic modulus) of the obtained complex elastic modulus is determined, and the maximum peak temperature of tan δ is defined as the glass transition temperature (°C).

The gel fraction after curing of the active energy ray-curable pressure-sensitive adhesive composition is preferably 10% by weight or more, more preferably 20 to 99% by weight, and particularly preferably 20 to 99% by weight, from the viewpoint of durability and adhesive strength. is 30 to 95% by weight, more preferably 40 to 90% by weight. If the gel fraction is too low, cohesive strength tends to decrease, resulting in a decrease in durability. In addition, if the gel fraction is too high, there is a concern that the cohesive force will increase and the adhesive force will decrease.

The gel fraction is a measure of the degree of cross-linking, and is calculated, for example, by the following method. A cured coating film sheet (without a separator) in which a cured coating film is formed on a polymer sheet (for example, PET film, etc.) serving as a base material is wrapped in a 200-mesh SUS wire mesh, and placed in toluene at 23 ° C. × Immerse for 24 hours. The weight percentage of the undissolved cured coating film components remaining in the wire mesh after immersion with respect to the weight of the cured coating film components before immersion is defined as the gel fraction. The weight of the components of the cured coating film before and after immersion is the value obtained by subtracting the weight of the substrate from the measured weight.

Since the active energy ray-curable adhesive composition of the present invention can use a plant-derived dimer acid as a raw material, it is an active energy ray-curable adhesive composition with reduced environmental load. The biomass rate can be represented by the percentage of plant-derived carbon atoms in the total carbon contained in the active energy ray-curable pressure-sensitive adhesive composition, and is preferably 30C% (C% represents the percentage of carbon) or more. , more preferably 40 C% or more, and particularly preferably 50 C% or more. The biomass rate is the carbon number of all the raw materials constituting the active energy ray-curable pressure-sensitive adhesive composition, that is, the polyester polyol (a1), the polyvalent isocyanate (a2), the hydroxyl group-containing (meth)acrylate (a3-1), It can be calculated by calculating the ratio of the number of carbon atoms in the plant-derived raw material to the total number of carbon atoms in the ethylenically unsaturated monomer (B). Moreover, as a method for more accurate calculation, measurement by the method specified in ASTM D5866 can be mentioned.

<Adhesive composition/adhesive>
INDUSTRIAL APPLICABILITY The active energy ray-curable pressure-sensitive adhesive composition of the present invention has good adhesion to various members, and can be applied to various uses such as electronic members and vehicles.
Examples of the adherend include SUS, glass, plastic (film), and the like. Examples of plastics (films) include polymethylmethacrylate (PMMA) and polycarbonate (PC).

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the examples, "parts" and "%" mean weight basis.
In addition, the number average molecular weight, weight average molecular weight, degree of dispersion, glass transition temperature after curing, and gel fraction of the urethane (meth)acrylate compound were measured according to the methods described above, and the biomass ratio was calculated according to the methods described above.

[Preparation of urethane acrylate (A-1)]
A flask equipped with an internal thermometer, a stirrer, and a condenser was charged with 743.2 parts of a bifunctional polyester polyol (a1) (hydroxyl value of 56 mgKOH/g, number average molecular weight of 2004) and isophorone diisocyanate as a polyvalent isocyanate (a2). 167.8 parts of (IPDI), 0.4 parts of 2,6-di-t-butyl-p-cresol as a polymerization inhibitor, and 0.06 parts of dibutyltin dilaurate as a reaction catalyst were added and reacted at 60°C. Then, 89.0 parts of 2-hydroxyethyl acrylate (HEA) (a3-1) was added to this system and reacted. 1) A composition containing (weight average molecular weight (Mw): 9300, number average molecular weight (Mn): 3500, degree of dispersion: 2.7) was obtained.

[Preparation of urethane acrylate (A-2)]
A flask equipped with an internal thermometer, a stirrer, and a condenser was charged with 866.3 parts of a bifunctional polyester polyol (a1) (hydroxyl value of 56 mgKOH/g, number average molecular weight of 2004) and isophorone diisocyanate as a polyvalent isocyanate (a2). 112.1 parts of (IPDI), 0.4 parts of 2,6-di-t-butyl-p-cresol as a polymerization inhibitor, and 0.06 parts of dibutyltin dilaurate as a reaction catalyst were added and reacted at 60°C. Then, 21.6 parts of 4-hydroxybutyl acrylate (4HBA) (a3-1) was added to this system, and the reaction was allowed to proceed. 2) A composition containing (weight average molecular weight (Mw): 32300, number average molecular weight (Mn): 15700, dispersity: 2.1) was obtained.

[Preparation of urethane acrylate (A-3)]
A flask equipped with an internal thermometer, a stirrer, and a condenser was charged with 723.2 parts of a bifunctional polyester polyol (a1) (hydroxyl value of 56 mgKOH/g, number average molecular weight of 2004) and isophorone diisocyanate as a polyvalent isocyanate (a2). 163.3 parts of (IPDI), 0.4 parts of 2,6-di-t-butyl-p-cresol as a polymerization inhibitor, and 0.06 parts of dibutyltin dilaurate as a reaction catalyst were added and reacted at 60°C. Then, 53.0 parts of 4-hydroxybutyl acrylate (4HBA) (a3-1) and 60.5 parts of decanol (a3-2) were added to this system and reacted until the residual isocyanate groups reached 0.1% or less. to obtain a composition containing urethane acrylate (A-3) (weight average molecular weight (Mw): 9200, number average molecular weight (Mn): 3300, degree of dispersion: 2.8).

[Preparation of urethane acrylate (A-4)]
A flask equipped with an internal thermometer, a stirrer, and a condenser was charged with 858.1 parts of a bifunctional polyester polyol (a1) (hydroxyl value of 60 mgKOH/g, number average molecular weight of 1870) and isophorone diisocyanate as a polyvalent isocyanate (a2). 119.0 parts of (IPDI), 0.4 parts of 2,6-di-t-butyl-p-cresol as a polymerization inhibitor, and 0.06 parts of dibutyltin dilaurate as a reaction catalyst were added and reacted at 60°C. Then, 22.9 parts of 4-hydroxybutyl acrylate (4HBA) (a3-1) was added to this system, and the reaction was allowed to proceed. 4) A composition containing (weight average molecular weight (Mw): 22100, number average molecular weight (Mn): 9200, dispersity: 2.4) was obtained.

[Preparation of urethane acrylate (A-5)]
A flask equipped with an internal thermometer, a stirrer, and a condenser was charged with 801.4 parts of a bifunctional polyester polyol (a1) (hydroxyl value of 56 mgKOH/g, number average molecular weight of 2004) and isophorone diisocyanate as a polyvalent isocyanate (a2). 135.7 parts of (IPDI), 0.4 parts of 2,6-di-t-butyl-p-cresol as a polymerization inhibitor, and 0.06 parts of dibutyltin dilaurate as a reaction catalyst were added and reacted at 60°C. Then, 29.4 parts of 4-hydroxybutyl acrylate (4HBA) (a3-1) and 33.5 parts of decanol (a3-2) were added to this system and reacted until the residual isocyanate groups reached 0.1% or less. to obtain a composition containing urethane acrylate (A-4) (weight average molecular weight (Mw): 14600, number average molecular weight (Mn): 5500, degree of dispersion: 2.7).

[Preparation of urethane acrylate (A-6)]
In a flask equipped with an internal thermometer, a stirrer, and a condenser, 785.5 parts of a bifunctional polyester polyol (a1) (hydroxyl value 62.7 mgKOH/g, number average molecular weight 1750), as a polyvalent isocyanate (a2) 146.6 parts of isophorone diisocyanate (IPDI), 0.4 parts of 2,6-di-t-butyl-p-cresol as a polymerization inhibitor, and 0.06 parts of dibutyltin dilaurate as a reaction catalyst were added and reacted at 60°C. rice field. Then, 31.7 parts of 4-hydroxybutyl acrylate (4HBA) (a3-1) and 36.2 parts of decanol (a3-2) were added to this system and reacted, when the residual isocyanate groups became 0.1% or less. to obtain a composition containing urethane acrylate (A-6) (weight average molecular weight (Mw): 13000, number average molecular weight (Mn): 6000, degree of dispersion: 2.2).

[Preparation of urethane acrylate (A'-1)]
A flask equipped with an internal thermometer, a stirrer, and a condenser was charged with 844.1 parts of a bifunctional polyether polyol (a1) (hydroxyl value of 56.7 mgKOH/g, number average molecular weight of 2000) and a polyvalent isocyanate (a2). 126.4 parts of isophorone diisocyanate (IPDI) as a polymerization inhibitor, 0.02 parts of 2,6-di-t-butyl-p-cresol as a polymerization inhibitor, and 0.06 parts of dibutyltin dilaurate as a reaction catalyst were added and reacted at 60 ° C. let me Then, 20.5 parts of 4-hydroxybutyl acrylate (4HBA) (a3-1) and 9.0 parts of isopropyl alcohol (a3-2) were added to this system and reacted, and the residual isocyanate groups became 0.1% or less. At this point, the reaction was terminated to obtain a composition containing urethane acrylate (A-6) (weight average molecular weight (Mw): 33000, number average molecular weight (Mn): 16500, dispersity: 2.0).

[Ethylenically unsaturated monomer (B)]
The following were prepared as the ethylenically unsaturated monomers (B1) and (B2).
(B1-1) isobornyl acrylate (Tg = 97°C)
(B1-2) dicyclopentanyl acrylate (Tg = 120°C)
(B1-3) acryloylmorpholine (Tg = 145°C)
(B2-1) Tetrahydrofurfuryl acrylate (Tg = -12°C)
(B2-2) Cyclohexyl acrylate (Tg = 15°C)
(B2-3) n-butyl acrylate (Tg = -56°C)

<Example 1>
[Preparation of active energy ray-curable adhesive composition]
The urethane acrylate (A-1) obtained above, the ethylenically unsaturated monomers (B1-1) and (B2-1) were blended so as to have the composition shown in Table 2, and a photopolymerization initiator was added. As (C), 4 parts of Omnilad 184 (1-hydroxycyclohexylphenyl ketone, manufactured by IGMRESINS) is blended with respect to a total of 100 parts of a urethane (meth)acrylate compound and an ethylenically unsaturated monomer, and an active energy ray-curable adhesive. An agent composition was obtained.
The resulting active energy ray-curable pressure-sensitive adhesive composition was evaluated for adhesiveness in the following manner. The stickiness results are shown in Table 2 together with the biomass ratio.

〔Adhesive force〕
[Preparation of adhesive sheet for adhesive strength measurement (without lamination)]
The resulting active energy ray-curable pressure-sensitive adhesive composition was applied to an easy-adhesion treated polyethylene terephthalate (PET) film (thickness: 125 µm) using an applicator so that the film thickness after curing was 100 µm. Under the conditions of 80 W/cm (high-pressure mercury lamp) x 18 cmH x 1.9 m/min x 3 passes (accumulated irradiation amount 2,400 mJ/cm ² ) with the device (manufactured by igraphics, “conveyor-type tabletop irradiation device”) A pressure-sensitive adhesive sheet for measuring the pressure-sensitive adhesive strength was obtained by irradiating with ultraviolet rays and curing the pressure-sensitive adhesive sheet.

(Test method)
After cutting the obtained adhesive sheet for adhesive force measurement into 25 mm × 100 mm, a stainless steel plate (SUS304BA plate) as an adherend was reciprocated twice using a 2 kg rubber roller in an atmosphere of 23 ° C. and a relative humidity of 50%. A test piece was produced by crimping by pressing. After this test piece was allowed to stand in the same atmosphere for 30 minutes, a 180 degree peel test was performed at a peel rate of 0.3 m/min to measure the adhesive strength (N/25 mm).

[Production of adhesive sheet (with laminate) for adhesive strength measurement]
The resulting active energy ray-curable resin composition was applied to an easy-adhesion treated polyethylene terephthalate (PET) film (thickness: 125 µm) using an applicator so that the film thickness after curing was 100 µm, and a release film (thickness: 38 μm).
80 W / cm (high pressure mercury lamp) × 18 cmH × 1.9 m / min × with a desktop UV irradiation device (manufactured by igraphics, “conveyor type desktop irradiation device”) while the UV irradiation surface is not exposed to air A pressure-sensitive adhesive sheet for measuring pressure-sensitive adhesive strength was obtained by curing by irradiating with ultraviolet rays under the condition of 3 passes (accumulated irradiation amount: 2400 mJ/cm2).

(Test method)
The obtained adhesive sheet for adhesive force measurement was cut into 25 mm × 100 mm, and after peeling off the release film, 2 kg was applied to a stainless steel plate (SUS304BA plate) as an adherend under an atmosphere of 23 ° C. and a relative humidity of 50%. A rubber roller was used to reciprocate two times for pressure bonding to prepare a test piece. After this test piece was allowed to stand in the same atmosphere for 30 minutes, a 180 degree peel test was performed at a peel speed of 0.3 m/min to measure the adhesive strength (N/25 mm).

<Examples 2 to 8, Comparative Examples 1 to 3>
In Example 1, polyester polyol (a1), polyvalent isocyanate (a2), hydroxyl group-containing (meth)acrylate (a3-1), ethylenically unsaturated monomer (B-1), ethylenically unsaturated monomer (B-2 ), except that the type and charge of the reaction catalyst were changed as shown in Table 1, to obtain an active energy ray-curable pressure-sensitive adhesive composition.
The resulting active energy ray-curable adhesive composition was evaluated for adhesiveness in the same manner as in Example 1. The stickiness results are shown in Table 1 (without laminate) and Table 2 (with laminate) along with biomass percentage.

From the above results, the active energy ray-curable pressure-sensitive adhesive compositions of Examples 1 to 8 were urethane acrylates with a specific Tg and had good adhesive strength when pressure-sensitive adhesives were prepared.
On the other hand, the active energy ray-curable pressure-sensitive adhesive compositions of Comparative Examples 1 and 2, in which the glass transition temperature of the cured product is outside the specified range of the present invention, were inferior in adhesive strength as a pressure-sensitive adhesive.

INDUSTRIAL APPLICABILITY The active energy ray-curable pressure-sensitive adhesive composition of the present invention has good adhesive strength and can be widely used as a surface protective sheet for metal plates, glass plates, plastic plates, resin-coated surfaces, and the like. In addition, the active energy ray-curable pressure-sensitive adhesive composition of the present invention can also be used as a sheet (tape) for fixing electronic parts, a seal (tape) for labeling electronic parts, and a lamination resin for optical displays or touch centers. is. For example, it can be suitably used for various applications such as bonding an optical display panel and a touch panel, bonding an optical display panel and an optical display panel, and bonding an optical display panel and a parallax barrier.

Claims (7)

A urethane (meth)acrylate compound (A) which is a reaction product of a polyester polyol (a1), a polyvalent isocyanate (a2), and a hydroxyl group-containing (meth)acrylate (a3-1) and/or a monool (a3-2) and,
An active energy ray-curable pressure-sensitive adhesive composition containing an ethylenically unsaturated monomer (B),
An active energy ray-curable pressure-sensitive adhesive composition, wherein the cured product (I) of the active energy ray-curable pressure-sensitive adhesive composition has a glass transition temperature of more than 20°C and 85°C or less. 2. The active energy ray-curable pressure-sensitive adhesive composition according to claim 1, wherein the polyester polyol (a1) has a number average molecular weight of 500 to 5,000. 3. The active energy ray according to claim 1, wherein the polyvalent isocyanate (a2) contains at least one selected from the group consisting of aliphatic polyvalent isocyanates and alicyclic polyvalent isocyanates. A curable adhesive composition. 4. The active energy ray-curable pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the urethane (meth)acrylate compound (A) has a number average molecular weight of 500 to 30,000. The ethylenically unsaturated monomer (B) is an ethylenically unsaturated monomer (B1) having a glass transition temperature of 0°C or higher and 130°C or lower, and/or an ethylenic monomer having a glass transition temperature of -60°C or higher and lower than 0°C. 5. The active energy ray-curable pressure-sensitive adhesive composition according to any one of claims 1 to 4, characterized by containing an unsaturated monomer (B2). 6. The active energy ray-curable pressure-sensitive adhesive composition according to any one of claims 1 to 5, further comprising a photopolymerization initiator (C). A pressure-sensitive adhesive obtained by curing the active energy ray-curable pressure-sensitive adhesive composition according to any one of claims 1 to 6.