WO2015190558A1

WO2015190558A1 - Double-sided adhesive sheet for image display devices, and article

Info

Publication number: WO2015190558A1
Application number: PCT/JP2015/066885
Authority: WO
Inventors: 照士高橋; 研二芥; 康弘穂積; 吉浩箱根; 徳田　清久; 貴文水口; 英照亀谷; 隼本橋
Original assignee: 日本化薬株式会社
Priority date: 2014-06-11
Filing date: 2015-06-11
Publication date: 2015-12-17
Also published as: CN106459724A; TW201602278A

Abstract

　Provided is a double-sided adhesive sheet for image display devices, said adhesive sheet being readily producible and imparting minimal damage to optical base materials, enabling optical members such as display units having good curability and adhesiveness to be obtained, and enabling optical members (touch panels) having high adhesiveness and adhesive strength with respect to base materials to be obtained. Said adhesive sheet includes: a softener component (G), and a (meth)acrylate (K) comprising at least one compound selected from the group consisting of a urethane (meth)acrylate, a (meth)acrylate having a polyisoprene skeleton, and a (meth)acrylate having a butadiene skeleton.

Description

Double-sided pressure-sensitive adhesive sheet for image display device and article

The present invention relates to an ultraviolet curable adhesive composition for image display for laminating at least two optical substrates, a double-sided pressure-sensitive adhesive sheet using the ultraviolet curable adhesive composition for image display, and an optical device using the same The present invention relates to a method of manufacturing a member.

In recent years, display devices that allow screen input by attaching a touch panel to a display screen of a display device such as a liquid crystal display, a plasma display, or an organic EL display have been widely used. In this touch panel, a glass plate or a resin film on which a transparent electrode is formed is bonded with a slight gap facing each other. If necessary, a transparent protection made of glass or resin is provided on the touch surface. It has a structure in which plates are bonded together.

There is a technique of using a double-sided pressure-sensitive adhesive sheet for bonding a glass plate or film on which a transparent electrode is formed on a touch panel and a transparent protective plate made of glass or resin, or bonding a touch panel and a display unit. For example, in Patent Document 1, as a transparent double-sided pressure-sensitive adhesive sheet for bonding a transparent protective plate such as glass or plastic and an image display device, a (meth) acrylic acid derivative, a (meth) acrylic acid derivative polymer, and a polyfunctional (meth) A transparent double-sided pressure-sensitive adhesive sheet obtained by curing a mixture containing an acrylic acid derivative has been proposed.

On the other hand, a technique for bonding a transparent protective plate and an image display device with an ultraviolet curable adhesive composition has been proposed (Patent Document 2). However, since the production efficiency can be improved by using the transparent double-sided pressure-sensitive adhesive sheet as compared with the method using the ultraviolet curable adhesive composition, there is an advantage over the ultraviolet curable adhesive composition. On the other hand, if the curable component is not polymerized, it is difficult to form a sheet in the case where a conventional general ultraviolet curable adhesive composition is made into a transparent double-sided pressure-sensitive adhesive sheet, and the desired curing is achieved. It was difficult to obtain physical properties.
Therefore, it has been desired to develop a transparent double-sided pressure-sensitive adhesive sheet that can ensure cured properties such as low dielectric constant, adhesion, and low shrinkage.

Japanese Unexamined Patent Publication No. 2009-057550 Japanese Unexamined Patent Publication No. 2012-046658

The present invention can obtain an optical member such as a display unit having little damage to the optical substrate, good productivity, good curability and adhesion, and has high adhesion to the substrate. It aims at providing the double-sided adhesive sheet for image display apparatuses which can obtain an optical member (touch panel etc.) with high intensity | strength.

The present inventors have completed the present invention as a result of intensive studies in order to solve the above problems. That is, the present invention relates to the following (1) to (15).
(1) At least one (meth) acrylate (K) selected from the group consisting of urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, or (meth) acrylate having a butadiene skeleton, and a softening agent component The double-sided adhesive sheet for image display apparatuses containing (G).
(2) at least one (meth) acrylate (K) selected from the group consisting of urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton or (meth) acrylate having a butadiene skeleton, a softener component The double-sided adhesive sheet for image display apparatuses obtained by drying the ultraviolet curable resin composition containing (G) at 80 degreeC or more.
(3) The (meth) acrylate is urethane (meth) acrylate, and the urethane (meth) acrylate reacts the compound (A), the compound (B), the compound (C) and the compound (D) shown below. The double-sided pressure-sensitive adhesive sheet for image display devices according to (1) or (2), which is a polyurethane compound (E) obtained in this way.
Compound (A): Hydrogenated polybutadiene polyol compound Compound (B): Polyisocyanate compound Compound (C): (Meth) acrylate compound having at least one hydroxyl group Compound (D): Diol compound other than compound (A) ( 4) A double-sided pressure-sensitive adhesive sheet for an image display device, comprising the polyurethane compound (E) according to (3), wherein the hydrogenated polybutadiene polyol compound (A) has an iodine value of 20 or less.
(5) The double-sided pressure-sensitive adhesive sheet for an image display device comprising the polyurethane compound (E) according to (3) or (4), wherein the polyisocyanate compound (B) is an aliphatic diisocyanate compound.
(6) The polyurethane compound (E) according to any one of (3) to (5), wherein the (meth) acrylate compound (C) having at least one hydroxyl group is 2-hydroxyethyl (meth) acrylate. A double-sided pressure-sensitive adhesive sheet for an image display device, comprising:
(7) The diol compound (D) other than the compound (A) includes the polyurethane compound (E) according to any one of (3) to (6), which is a polyether polyol. Double-sided adhesive sheet.
(8) A double-sided pressure-sensitive adhesive sheet for an image display device, comprising the polyurethane compound (E) according to any one of (1) to (7) and a polymerizable compound (F) other than (E).
(9) The softening agent component (G) includes any one of a hydroxyl group-containing polymer and a terpene resin, or both, according to any one of (1) to (8) Double-sided pressure-sensitive adhesive sheet for image display devices.
(10) A cured product obtained by irradiating the double-sided pressure-sensitive adhesive sheet for image display device according to any one of (1) to (9) with active energy rays.
(11) A touch panel comprising the double-sided pressure-sensitive adhesive sheet for an image display device according to any one of (1) to (9).
(12) At least one (meth) acrylate (K) or softener component selected from the group consisting of urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, or (meth) acrylate having a butadiene skeleton The double-sided adhesive sheet for image display apparatuses containing (G).
(13) At least one (meth) acrylate (K) selected from the group consisting of urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, or (meth) acrylate having a butadiene skeleton, a softener component The double-sided adhesive sheet for image display apparatuses containing (G) and a solvent.
(14) The optical base material is pasted by the following steps 1 and 2 using the double-sided pressure-sensitive adhesive sheet for an image display device according to any one of (1) to (9) and (12) to (13). A method for manufacturing an image display device, which also provides an image display device.
(Process 1) The process of peeling the single-sided release film of the double-sided adhesive sheet for image display apparatuses with a release film with respect to at least 1 optical base material, and arrange | positioning the double-sided adhesive sheet for image display apparatuses.
(Process 2) The process of peeling off the release film of the remaining single side | surface of the double-sided adhesive sheet for image display apparatuses arrange | positioned at the process 1, and bonding another optical base material.
(15) The optical base material is pasted by the following steps 1 to 3 using the double-sided pressure-sensitive adhesive sheet for an image display device according to any one of (1) to (9) and (12) to (13). A method for manufacturing an image display device, which also provides an image display device.
(Process 1) The process of peeling the single-sided release film of the double-sided adhesive sheet for image display apparatuses with a release film with respect to at least 1 optical base material, and arrange | positioning the double-sided adhesive sheet for image display apparatuses.
(Process 2) The process of peeling off the release film of the remaining single side | surface of the double-sided adhesive sheet for image display apparatuses arrange | positioned at the process 1, and bonding another optical base material.
(Process 3) The process of irradiating an ultraviolet-ray through the optical base material which has a light-shielding part to the double-sided adhesive sheet for image display apparatuses in the bonded optical base material, and hardening this hardened | cured material layer.

The cured film of the double-sided pressure-sensitive adhesive sheet for image display device of the present invention is excellent in flexibility and has high moisture resistance, heat resistance, and light resistance. It is possible to effectively prevent problems from occurring.

The double-sided PSA sheet for an image display device of the present invention is at least one (meth) selected from the group consisting of urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, or (meth) acrylate having a butadiene skeleton. Contains acrylate (K) or softener component (G). In addition, it is preferable that both the said (meth) acrylate (K) and the softening agent component (G) are included.

The double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is selected from the group consisting of urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, and (meth) acrylate having a polybutadiene skeleton as (meth) acrylate (K). Use one that will be. Preferably, it is an embodiment containing at least one of urethane (meth) acrylate or (meth) acrylate having a polyisoprene skeleton. Here, the (meth) acrylate compound is preferably a high molecular weight oligomer or polymer. Here, the polymer means a high molecular weight body that does not include a (meth) acrylic polymer that is a high molecular weight body in which a (meth) acryl group is polymerized, and a (meth) acryloyl group remains.
In the present specification, “(meth) acrylate” means either one or both of methacrylate and acrylate. The same applies to “(meth) acrylic acid” and the like.

The urethane (meth) acrylate that can be suitably used for the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is obtained by reacting at least one hydroxy compound having a (meth) acryloyloxy group and an isocyanate compound (further as an optional component, a polyol). It is the (meth) acrylate obtained.

Specific examples of the hydroxy compound having at least one (meth) acryloyloxy group include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4- Hydroxyethyl (meth) acrylate, cyclohexanedimethanol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) ) A (meth) acrylate compound having various hydroxyl groups such as acrylate, and a ring-opening reaction product of the above-mentioned (meth) acrylate compound having a hydroxyl group and ε-caprolactone. Door can be.

Specific examples of the isocyanate compound include, for example, P-phenylene diisocyanate, m-phenylene diisocyanate, P-xylene diisocyanate, m-xylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4 ′. -Aromatic diisocyanates such as diphenylmethane diisocyanate and naphthalene diisocyanate; aliphatic or alicyclic diisocyanates such as isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hydrogenated xylene diisocyanate, norbornene diisocyanate, lysine diisocyanate ; Trimerization of one or more burettes of isocyanate monomers or the above diisocyanate compounds Polyisocyanates of the isocyanate and the like; the and the isocyanate compound include polyisocyanates obtained by urethane reaction of the polyol compound.

The polyol that can be used as an optional component is not particularly limited as long as it is a known polyol. Specific examples include, for example, polyether polyols such as polyethylene glycol, polybutylene glycol, polytetramethylene glycol, polypropylene glycol and polyethylene glycol, and polyester polyols such as polyethylene glycol adipate, poly 1,4-butanediol adipate and polycaprolactone. Glycols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol and neopentyl glycol, cyclohexane dimethylol, polyisoprene glycol, polybutadiene glycol, hydrogenated bisphenol A, hydrogenated bisphenol F, spiro skeleton-containing alcohol, Alicyclic alkanes such as tricyclodecane dimethylol and pentacyclopentadecane dimethylol And alkylene oxide adducts thereof, hydrogenated polyisoprene, branched or linear long chain alkyl diols such as diols of hydrogenated polybutadiene, bisphenols such as bisphenol A and bisphenol F, and alkylene oxide adducts of bisphenols, Examples include polyols such as trimethylolpropane, ditrimethylolpropane, pentaerythritol and dipentaerythritol, alkylene oxide adducts of these polyols, and polyester polyols obtained by reaction of these polyols with polybasic acids such as adipic acid. be able to. Although there is no particular limitation, it is particularly preferable to use polyether polyols in order to improve flexibility and compatibility in the cured product of the ultraviolet curable adhesive composition of the present invention.

The weight average molecular weight of the urethane (meth) acrylate is preferably about 5,000 to 100,000, and more preferably 10,000 to 80,000. When the weight average molecular weight is less than 5000, shrinkage increases, and when the weight average molecular weight is greater than 100,000, the curability is poor.

In the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention, urethane (meth) acrylate can be used alone or in combination of two or more at any ratio. The weight ratio of urethane (meth) acrylate in the ultraviolet curable agent composition for obtaining the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is usually 20 to 80% by weight, preferably 30 to 70% by weight.

The (meth) acrylate having the polyisoprene skeleton has a (meth) acryloyl group at the terminal or side chain of the polyisoprene molecule. A (meth) acrylate having a polyisoprene skeleton can be obtained as “UC-203” (manufactured by Kuraray Co., Ltd.). The (meth) acrylate having a polyisoprene skeleton preferably has a polystyrene-equivalent number average molecular weight of 1,000 to 50,000, more preferably about 25,000 to 45,000.
The weight ratio of the (meth) acrylate having a polyisoprene skeleton in the photocurable transparent adhesive composition for obtaining the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is usually 20 to 80% by weight, preferably 30 to 70% by weight. %.

The (meth) acrylate having the polybutadiene skeleton has a (meth) acryloyl group at the terminal or side chain of the polybutadiene molecule. The (meth) acrylates having a polybutadiene skeleton are "TEAI-1000 (Nippon Soda Co., Ltd.)", "TE-2000 (Nippon Soda Co., Ltd.)", "EMA-3000 (Nippon Soda Co., Ltd.)" Manufactured by Kogyo Co., Ltd.). The (meth) acrylate having a polybutadiene skeleton preferably has a polystyrene-equivalent number average molecular weight of 1,000 to 30,000, more preferably about 1,000 to 10,000.
The weight ratio of the (meth) acrylate having a polybutadiene skeleton in the photocurable transparent adhesive composition for obtaining the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is usually 10 to 80% by weight, preferably 20 to 70% by weight. It is.

The polyurethane compound (E) that can be used particularly preferably in the present invention is a reaction between the hydrogenated polybutadiene polyol (A) and the diol compound (D) other than the compound (A) and the polyisocyanate compound (B) (hereinafter referred to as “first”). And a (meth) acrylate compound (C) having at least one hydroxyl group is reacted with the remaining isocyanate group (hereinafter referred to as a second reaction). The resulting polyurethane compound (E) preferably has a weight average molecular weight of 5,000 to 100,000, more preferably 10,000 to 80,000, particularly preferably 30,000 to 70,000. The R value is preferably 1.1 to 2.0, more preferably 1.1 to 1.5.

As the hydrogenated polybutadiene polyol (A) used in the first reaction of the present invention, any hydrogenated reduction product of a general polybutadiene polyol can be used. The iodine value is particularly preferably 20 or less.
The hydroxyl value is preferably 400 or less, and more preferably 300 or less. Although a minimum is not specifically limited, For example, what is necessary is just 0.1 or more. As for the molecular weight of (A), all generally available molecular weight distributions can be used, but those having a weight average molecular weight of 500 to 3000 are particularly preferred particularly when the balance between flexibility and curability is achieved. . On the other hand, with respect to the molecular weight of (A), all generally available molecular weight distributions can be used, but those having a number average molecular weight of 500 to 5000 are preferred particularly when the balance between flexibility and curability is achieved. Those of 500 to 3000 are particularly preferred.
Examples of commercially available hydrogenated polybutadiene polyols (A) include Nippon Soda Co., Ltd .: GI-1000, GI-2000, GI-3000, CRAY VALLEY KRASOL HLBP-H 1000, HLBP-H 2000, HLBP-H 3000 etc. are mentioned. In addition, what contains an alkali salt can be used conveniently.

Specific examples of the diol compound (D) other than the compound (A) used in the first reaction of the present invention include, for example, polyethers such as polyethylene glycol, polybutylene glycol, polytetramethylene glycol, polypropylene glycol, and polyethylene glycol. Polyols, polyethylene glycol adipate, poly 1,4-butanediol adipate, polyester polyols such as polycaprolactone, glycols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol and neopentyl glycol, cyclohexane dimethylol, Polyisoprene glycol, polybutadiene glycol, hydrogenated bisphenol A, hydrogenated bisphenol F, spiro skeleton-containing alcohol, tricyclodeca Aliphatic alcohols such as dimethylol and pentacyclopentadecane dimethylol and their alkylene oxide adducts, hydrogenated polyisoprene, branched or linear long chain alkyl diols such as hydrogenated polybutadiene diols, bisphenol A, bisphenol F, etc. Bisphenols, and alkylene oxide adducts of bisphenol, polyols such as trimethylolpropane, ditrimethylolpropane, pentaerythritol and dipentaerythritol, and alkylene oxide adducts of these polyols, as well as polybasic compounds such as these polyols and adipic acid The polyester polyol obtained by reaction of an acid etc. can be mentioned. Although there is no particular limitation, it is particularly preferable to use polyether polyols in order to improve flexibility and compatibility in the cured product of the ultraviolet curable adhesive composition of the present invention.
As for the molecular weight of the diol compound (D) other than the compound (A), all generally available molecular weight distributions can be used, but the number average molecular weight is particularly 50 when the balance between flexibility and curability is achieved. ˜6000 is preferred, and 100˜4000 is particularly preferred.
Here, in the obtained polyurethane compound (E), the structure derived from the diol compound (D) other than the compound (A) (particularly preferably a polyether polyol such as polyethylene glycol) is dispersedly incorporated, and the polyethylene glycol skeleton and water are incorporated. From the viewpoint of enhancing the compatibility with the monomer by uniformly incorporating the additive polybutadiene skeleton, the number average molecular weight of polyethylene glycol is more preferably 2000 or less, and particularly preferably 500 or less.
In the polyurethane compound (E), a diol compound (D) other than the compound (A) (particularly preferably a polyether polyol such as polyethylene glycol) is a diol other than the hydrogenated polybutadiene polyol (A) and the compound (A). In view of the total number of moles with the compound (D) (particularly preferably a polyether polyol such as polyethylene glycol), it is preferably incorporated in an amount of 5 to 10 mol%.
The hydroxyl value is preferably 400 or less, and more preferably 300 or less. Although a minimum is not specifically limited, For example, what is necessary is just 5 or more.

As a specific example of polyethylene glycol which is an example of polyether polyols that can be suitably used in the first reaction of the present invention, all commercially available polyethylene glycols can be used. PEG # 200T, PEG # 200, PEG # 300, PEG # 400, PEG # 600, PEG # 1000, PEG # 1500, PEG # 1540, PEG # 200, PEG # 4000, PEG # 4000P, PEG # 6000, PEG # 6000P, PEG # 11000, PEG # 20000, and the like, and urethane grades and the like whose moisture are controlled can also be used. The water content is preferably 2% or less, particularly preferably 1% or less, in order to suppress thickening due to an increase in molecular weight.

Here, in the present invention, hydrogenated polybutadiene polyol (A) and diol compound (D) other than compound (A) (particularly preferably polyether polyol such as polyethylene glycol) are used for the reaction. ) And diol compound (D) other than compound (A) (particularly preferably, a polyether polyol such as polyethylene glycol) is not particularly limited, but (A) component: (D) component is 9.999 in molar ratio. : 0.001 to 1: 9 is preferable, 9.999: 0.001 to 3: 7 is more preferable, and 9.999: 0.001 to 4: 6 is particularly preferable.
The number average molecular weight of the hydrogenated polybutadiene polyol (A) used in the present invention is the number average molecular weight of a diol compound (D) other than the compound (A) used (particularly preferably a polyether polyol such as polyethylene glycol). It is preferable to use a larger one in combination. The number average molecular weight of the diol compound (D) other than the compound (A) (particularly preferably a polyether polyol such as polyethylene glycol) +500 is used as a hydrogenated polybutadiene polyol ( More preferably, the hydrogenated polybutadiene polyol (A) has a number average molecular weight of the diol compound (D) other than the compound (A) (particularly preferably a polyether polyol such as polyethylene glycol) +1000. Especially to have Masui.

The polyisocyanate compound (B) used in the first reaction is a compound comprising two or more isocyanate groups in one molecule. For example, an aliphatic diisocyanate compound, an aromatic diisocyanate compound, These trimers are exemplified. The aliphatic diisocyanate compound as used herein means a diisocyanate compound in which an isocyanate group is bonded to a chain carbon atom, and a diisocyanate compound in which an isocyanate group is bonded to a carbon atom of a cyclic saturated hydrocarbon, and an aromatic diisocyanate compound. Means an isocyanate compound in which an isocyanate group is bonded to a carbon atom of an aromatic ring.

Examples of the aliphatic diisocyanate compound include 1,6-hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,3-diisocyanate cyclohexane, 1,4-diisocyanate. Cyclohexane, dicyclohexylmethane-4,4'-diisocyanate, m-tetramethylxylene diisocyanate, p-tetramethylxylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,12-dodecamethylene diisocyanate, 2,2,4-trimethylcyclohexane Diisocyanate, 2,4,4-trimethylcyclohexane diisocyanate, 2,2,4-trimethylhexamethylene diiso Aneto, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate and the like.

Examples of aromatic diisocyanate compounds include tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, 1,6-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1,6-phenylene. And diisocyanate monomers such as diisocyanate.

Among these, an aliphatic diisocyanate compound and a trimer of the aliphatic diisocyanate compound are preferable because they improve the moisture resistance and heat resistance of the coating film. Examples of the trimer of the aliphatic diisocyanate compound include the above-mentioned aliphatic isocyanate-based isocyanurate-type polyisocyanates, and specific examples include hexamethylene diisocyanate and isophorone diisocyanate. These may be used alone or in a mixture.

In the present invention, the first reaction is charged in an equivalent relationship (B / (A + D)> 1: [NCO] / [OH] molar ratio) such that isocyanate groups remain after the reaction. When the preparation ratio is increased, a large amount of unreacted polyisocyanate compound (B) is present, which may affect the flexibility of the ultraviolet curable adhesive composition. On the other hand, when the preparation ratio is reduced, the molecular weight increases and the curability of the ultraviolet curable adhesive composition may be affected. Specifically, preferably, the OH group of the alcohol compound (A + D) is 0.1 to 0.9 mol with respect to 1.0 mol of the NCO group of the polyisocyanate compound (B).

In the present invention, the first reaction can be carried out without a solvent, but in a solvent having a high viscosity of the product and having no alcoholic hydroxyl group for improving workability or in a polymerizable compound (F) described later. It is preferable to do so. Specific examples of the solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, aromatic hydrocarbons such as benzene, toluene, xylene, and tetramethylbenzene, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and dipropylene glycol. Glycol ethers such as dimethyl ether, dipropylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, ethyl acetate, butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, propylene glycol monomethyl ether acetate , Propylene glycol monoethyl ether acetate, Propylene glycol monomethyl ether acetate, esters such as dialkyl glutarate, dialkyl succinate, dialkyl adipate, cyclic esters such as γ-butyrolactone, petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, solvent naphtha, etc. Can be carried out alone or in a mixed organic solvent.

The reaction temperature is usually in the range of 30 to 150 ° C, preferably 50 to 100 ° C. The end point of the reaction is confirmed by a decrease in the amount of isocyanate. A catalyst may be added for the purpose of shortening the reaction time. As this catalyst, either a basic catalyst or an acidic catalyst is used. Examples of the basic catalyst include amines such as pyridine, pyrrole, triethylamine, diethylamine, dibutylamine and ammonia, and phosphines such as tributylphosphine and triphenylphosphine. Examples of acidic catalysts include copper naphthenate, cobalt naphthenate, zinc naphthenate, tributoxyaluminum, titanium tetraisopropoxide, zirconium tetrabutoxide, aluminum chloride, tin octylate, octyltin trilaurate, dibutyltin dilaurate, Mention may be made of Lewis acid catalysts such as octyltin diacetate. The amount of these catalysts added is usually 0.1 to 1 part by weight based on 100 parts by weight of the total weight of the diol compound (A + D) and the polyisocyanate compound (B).

The polyurethane compound (E) of the present invention is obtained by reacting (second reaction) a (meth) acrylate compound (C) having at least one hydroxyl group with respect to the remaining isocyanate group after the first reaction. be able to.

The (meth) acrylate compound (C) having at least one hydroxyl group used in the second reaction is a compound having at least one hydroxyl group and one (meth) acrylate in each molecule. Include 2-hydroxyethyl (meth) acrylate, propylene glycol mono (meth) acrylate, butanediol mono (meth) acrylate, pentanediol mono (meth) acrylate, hexanediol mono (meth) acrylate, diethylene glycol mono (meth) acrylate , Dipropylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, tripropylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, polyethylene glycol Dihydric alcohols such as mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, neopentyl glycol mono (meth) acrylate, ethoxylated neopentyl glycol mono (meth) acrylate, and neopentyl glycol mono (meth) acrylate hydroxypivalate Mono (meth) acrylates of

Trimethylolpropane mono (meth) acrylate, ethoxylated trimethylolpropane mono (meth) acrylate, propoxylated trimethylolpropane mono (meth) acrylate, tris (2-hydroxyethyl) isocyanurate mono (meth) acrylate, glycerin mono (meta) ) Acrylate, trimethylolpropane di (meth) acrylate, ethoxylated trimethylolpropane di (meth) acrylate, propoxylated trimethylolpropane di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, glycerin Mono- and di (meth) acrylates of trivalent alcohols such as di (meth) acrylate, and some of the hydroxyl groups of these alcohols are alkyl groups or ε-caprolactates In modified mono- and di (meth) acrylate;

Pentaerythritol mono (meth) acrylate, dipentaerythritol mono (meth) acrylate, ditrimethylolpropane mono (meth) acrylate, pentaerythritol di (meth) acrylate, dipentaerythritol di (meth) acrylate, ditrimethylolpropane di (meth) Acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa Polyfunctional alcohols such as (meth) acrylate, ditrimethylolpropane hexa (meth) acrylate, etc. Data) and those having a hydroxyl group in acrylates, polyfunctional (meth) acrylate having a hydroxyl group partially modified with an alkyl group and ε- caprolactone hydroxyl groups of these alcohols, and the like.

Of the above-mentioned (meth) acrylate compound (C) having at least one hydroxyl group, 2-hydroxyethyl (meth) acrylate is particularly preferable from the viewpoint of excellent curability and flexibility. From the viewpoint of easy workability, a polymerizable compound (F) described later in the present invention may be added during the reaction.

The second reaction of the present invention is charged in an equivalent relationship such that the isocyanate group of the intermediate obtained after the first reaction is eliminated. Specifically, preferably, the OH group of the (meth) acrylate compound (C) having at least one hydroxyl group is 1.0 to 3.3 mol per 1.0 mol of the NCO group of the intermediate obtained after the first reaction. The amount is 0 mol, more preferably 1.0 to 2.0 mol.

The second reaction can also be carried out in the absence of a solvent, but it is preferably carried out in the above-mentioned solvent and / or in the polymerizable compound (F) described later in order to improve the workability because the product has a high viscosity. The reaction temperature is usually in the range of 30 to 150 ° C, preferably 50 to 100 ° C. The end point of the reaction is confirmed by a decrease in the amount of isocyanate. The aforementioned catalyst may be added for the purpose of shortening the reaction time.

Usually, a polymerization inhibitor such as 4-methoxyphenol is already added to the acrylate compound used as a raw material, but a polymerization inhibitor may be added again during the reaction. Examples of such polymerization inhibitors include hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butyl-4-cresol, 3-hydroxythiophenol, Examples include p-benzoquinone, 2,5-dihydroxy-p-benzoquinone, and phenothiazine. The amount used is 0.01 to 1% by weight based on the reaction raw material mixture.

The softener component (G) is used for the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention. Specific examples of the softener component that can be used include polymers or oligomers, phthalates, phosphates, glycol esters, citrates, aliphatic dibasic esters, fatty acid esters, epoxy plastics Agent, castor oil, terpene-based hydrogenated resin, terpene-based resin, the following general formula (1)

(In the formula, n represents an integer of 0 to 40, and m represents an integer of 10 to 50. R ¹ and R ² may be the same or different. R ¹ and R ^{2 each} have 1 to 18 alkyl groups, alkenyl groups having 1 to 18 carbon atoms, alkynyl groups having 1 to 18 carbon atoms, and aryl groups having 5 to 18 carbon atoms.)

And a compound having a structure represented by: Examples of the oligomer and polymer include an oligomer or a polymer having a polyisoprene skeleton, a polybutadiene skeleton, a polybutene skeleton or a xylene skeleton and an esterified product thereof. In some cases, a polymer or an oligomer having a polybutadiene skeleton and an ester thereof are used. It is preferable to use a compound. Specific examples of the polymer or oligomer having a polybutadiene skeleton and esterified products thereof include butadiene homopolymer, epoxy-modified polybutadiene, butadiene-styrene random copolymer, maleic acid-modified polybutadiene, and terminal hydroxyl group-modified liquid polybutadiene. Further, these softening agent components can be used in combination of two or more of the above components.
As the double-sided pressure-sensitive adhesive sheet for an image display device, it is preferable to use a solid softener component at room temperature (25 ° C.) because the sheet shape can be maintained while ensuring adhesion and low shrinkage. It is more preferable to use a solid softener component having a melting point of 80 ° C. or higher, and it is particularly preferable to use a solid softener component having a melting point of 100 ° C. or higher. Specific examples include aromatic modified terpene resins. Here, two or more types of solid softener components can be mixed and used.
The weight ratio of the softening agent component in the ultraviolet curable adhesive composition for obtaining the double-sided pressure-sensitive adhesive sheet for an image display device is usually 10 to 80% by weight, preferably 10 to 70% by weight.

As an ultraviolet curable resin composition for obtaining the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention, an organic solvent is usually contained together with the (meth) acrylate (K) and the softening agent component (G).
Although it does not specifically limit as an organic solvent which can be used, For example, alcohol, such as methanol, ethanol, isopropyl alcohol, dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran, a dioxane, toluene, xylene etc. are mentioned.

The double-sided pressure-sensitive adhesive sheet for an image display device of the present invention can contain a (meth) acrylate monomer as an optional component.
As the (meth) acrylate monomer, a (meth) acrylate having one (meth) acryloyl group in the molecule can be preferably used.
Here, the (meth) acrylate monomer indicates (meth) acrylate excluding the urethane (meth) acrylate, the following epoxy (meth) acrylate, and the (meth) acrylate having the polyisoprene skeleton.

Specific examples of the (meth) acrylate having one (meth) acryloyl basis in the molecule include isooctyl (meth) acrylate, isoamyl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, stearyl ( Alkyl (meth) acrylates having 5 to 20 carbon atoms such as (meth) acrylate, cetyl (meth) acrylate, isomyristyl (meth) acrylate, tridecyl (meth) acrylate, etc. (preferably 10 carbon atoms from the viewpoint of volatility and solubility) To 20 alkyl (meth) acrylates, more preferably 10 to 20 carbon atoms having a branched chain (meth) acrylate), benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, acryloylmorpholine, phenylglycine (Meth) acrylate, tricyclodecane (meth) acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 1-adamantyl acrylate, 2 -Having a cyclic skeleton such as methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, 1-adamantyl methacrylate, polypropylene oxide modified nonylphenyl (meth) acrylate, dicyclopentadieneoxyethyl (meth) acrylate, etc. ) Acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc. having a hydroxyl group and an alkyl (meth) acrylate having 1 to 5 carbon atoms , Ethoxydiethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, polyalkylene glycol (meth) acrylate such as polypropylene oxide modified nonylphenyl (meth) acrylate, ethylene oxide modified phenoxylated phosphoric acid (meth) acrylate, ethylene oxide modified butoxy And phosphoric acid (meth) acrylate and ethylene oxide-modified octyloxylated phosphoric acid (meth) acrylate. Among them, alkyl (meth) acrylates having 10 to 20 carbon atoms, 2-ethylhexyl carbitol acrylate, acryloylmorpholine, 4-hydroxybutyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isostearyl (meth) acrylate, dicyclo Pentenyloxyethyl (meth) acrylate and polypropylene oxide-modified nonylphenyl (meth) acrylate are preferred. In particular, from the viewpoint of resin flexibility, alkyl (meth) acrylate having 10 to 20 carbon atoms, dicyclopentenyloxyethyl (meth) Preferred are acrylate, polypropylene oxide-modified nonylphenyl (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate.
On the other hand, from the viewpoint of improving the adhesion to glass, an alkyl (meth) acrylate having 1 to 5 carbon atoms having a hydroxyl group and acryloylmorpholine are preferable, and acryloylmorpholine is particularly preferable.
Here, the (meth) acrylate monomer refers to (meth) acrylate excluding urethane (meth) acrylate, epoxy (meth) acrylate, and (meth) acrylate having a polyisoprene skeleton.

The composition of the present invention can contain (meth) acrylates other than (meth) acrylate having one (meth) acryloyl group as long as the characteristics of the present invention are not impaired. For example, tricyclodecane dimethylol di (meth) acrylate, dioxane glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, alkylene oxide modified bisphenol A type di (meth) acrylate Trimethylol C2-C10 alkanes such as caprolactone-modified hydroxypivalic acid neopentyl glycol di (meth) acrylate and ethylene oxide-modified phosphoric acid di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethyloloctane tri (meth) acrylate Tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, trimethylolpropane polypropoxytri ( Trimethylol C2-C10 alkane polyalkoxy tri (meth) acrylate such as acrylate, trimethylolpropane polyethoxypolypropoxy tri (meth) acrylate, tris [(meth) acryloyloxyethyl] isocyanurate, pentaerythritol tri ( (Meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate and other alkylene oxide modified trimethylolpropane tri (meth) acrylate pentaerythritol polyethoxytetra (meth) acrylate, Pentaerythritol polypropoxytetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrime Trimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.
In this invention, when using together, in order to suppress cure shrinkage, it is preferable to use mono- or bifunctional (meth) acrylate.

In the said ultraviolet curable adhesive composition, these (meth) acrylate monomer components can be used 1 type or in mixture of 2 or more types in arbitrary ratios. The weight ratio of the (meth) acrylate monomer in the photocurable transparent adhesive composition of the present invention is usually 5 to 70% by weight, preferably 10 to 50% by weight. When it is less than 5% by weight, the curability is poor, and when it is more than 70% by weight, shrinkage increases.
In the aspect including both (i) at least one of (i) urethane (meth) acrylate or (meth) acrylate having a polyisoprene skeleton and (ii) (meth) acrylate monomer in the ultraviolet curable adhesive composition , (I) and (ii) are generally 25 to 90% by weight, 40 to 90% by weight, more preferably 40 to 80% by weight, based on the total amount of the resin composition.

In the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention, epoxy (meth) acrylate can be used as long as the characteristics of the present invention are not impaired. Epoxy (meth) acrylate has a function of improving curability and improving the hardness and curing speed of a cured product. Epoxy (meth) acrylate is a general term for (meth) acrylate obtained by reacting an epoxy resin containing one or more functional epoxy groups with (meth) acrylic acid. (Meth) acrylic acid is reacted at a ratio of 0.9 to 1.5 mol, more preferably 0.95 to 1.1 mol, per 1 equivalent of epoxy group of the glycidyl ether type epoxy compound. The reaction temperature is preferably 80 to 120 ° C., and the reaction time is about 10 to 35 hours. In order to accelerate the reaction, it is preferable to use a catalyst such as triphenylphosphine, TAP, triethanolamine, or tetraethylammonium chloride. Further, in order to prevent polymerization during the reaction, for example, paramethoxyphenol, methylhydroquinone or the like can be used as a polymerization inhibitor. Specific examples of epoxy resins used as raw materials for epoxy (meth) acrylates include phenyl diglycidyl ethers such as hydroquinone diglycidyl ether, catechol diglycidyl ether, resorcinol diglycidyl ether; bisphenol-A type epoxy resin, bisphenol-F type epoxy Bisphenol-type epoxy compounds such as resins, bisphenol-S type epoxy resins, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane epoxy compounds; A type epoxy resin, hydrogenated bisphenol-F type epoxy resin, hydrogenated bisphenol-S type epoxy resin, hydrogenated 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexa Fluoropropane Epoxy Hydrogenated bisphenol-type epoxy compounds such as compounds; Halogenated bisphenol-type epoxy compounds such as brominated bisphenol-A type epoxy resins and brominated bisphenol-F type epoxy resins; Alicyclic diglycidyl such as cyclohexanedimethanol diglycidyl ether compounds Ether compounds; aliphatic diglycidyl ether compounds such as 1,6-hexanediol diglycidyl ether, 1,4-butanediol diglycidyl ether and diethylene glycol diglycidyl ether; polysulfide type diglycidyl ether compounds such as polysulfide diglycidyl ether; phenol Novolac epoxy resin, cresol novolac epoxy resin, trishydroxyphenylmethane epoxy resin, dicyclopentadienephenol Epoxy resins, biphenol type epoxy resin, bisphenol -A novolac epoxy resins, naphthalene skeleton-containing epoxy resin, a heterocyclic epoxy resin or the like.

An epoxy (meth) acrylate that can be suitably used in the present invention is a bisphenol A type epoxy (meth) acrylate obtained from a bisphenol A type epoxy compound. The weight average molecular weight of the epoxy (meth) acrylate is preferably 500 to 10,000.
The weight ratio of the epoxy (meth) acrylate in the ultraviolet curable adhesive composition of the present invention is usually 1 to 80% by weight, preferably 5 to 30% by weight.

The content ratio of (meth) acrylate in the ultraviolet curable resin composition for obtaining the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is preferably 25 to 90% by weight, based on the total amount of the ultraviolet curable adhesive composition. Is 40 to 90% by weight, more preferably 40 to 80% by weight.
In the ultraviolet curable adhesive composition, as the (meth) acrylate, at least one selected from the group consisting of the urethane (meth) acrylate, the (meth) acrylate having a polyisoprene skeleton, and the (meth) acrylate monomer The urethane (meth) acrylate content is 20 to 80% by weight, preferably 30 to 70% by weight, and the polyisoprene skeleton-containing (meth) acrylate content is 20 to 80% by weight. It is more preferable when the content ratio of the (meth) acrylate monomer is 5 to 70% by weight, preferably 10 to 50% by weight.
In the ultraviolet curable adhesive composition, the urethane (meth) acrylate or the (meth) acrylate having a polyisoprene skeleton is contained as the (meth) acrylate, and the content ratio is 20 to 80% by weight, preferably 30 to More preferably, it is 70% by weight and contains a (meth) acrylate monomer, and its content is 5 to 70% by weight, preferably 10 to 50% by weight.

Examples of the maleimide group-containing compound that can be used in the double-sided pressure-sensitive adhesive sheet for image display devices of the present invention include, for example, Nn-butylmaleimide, N-hexylmaleimide, 2-maleimidoethyl-ethyl carbonate, 2-maleimidoethyl- Monofunctional aliphatic maleimides such as propyl carbonate and N-ethyl- (2-maleimidoethyl) carbamate; alicyclic monofunctional maleimides such as N-cyclohexylmaleimide; N, N-hexamethylene bismaleimide, polypropylene glycol-bis Aliphatic bismaleimides such as (3-maleimidopropyl) ether and bis (2-maleimidoethyl) carbonate; alicyclic bismaleimides such as 1,4-dimaleimidocyclohexane and isophorone bisurethane bis (N-ethylmaleimide); Maleimide acetic acid Esterification of carboxymaleimide derivatives such as maleimide compounds obtained by esterification with polytetramethylene glycol and maleimide compounds by esterification of maleimidocaproic acid with tetraethylene oxide adduct of pentaerythritol and various (poly) ols Although the (poly) ester (poly) maleimide compound etc. which can be obtained can be mentioned, it is not limited to these. The content is 25 to 90% by weight, preferably 40 to 90% by weight, and more preferably 40 to 80% by weight, based on the total amount of the ultraviolet curable adhesive composition.

Examples of the (meth) acrylamide compound that can be used in the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention include monofunctional (meth) acrylamides such as acryloylmorpholine and N-isopropyl (meth) acrylamide; methylenebis (meth) acrylamide And polyfunctional (meth) acrylamides. The content is 25 to 90% by weight, preferably 40 to 90% by weight, more preferably 40 to 90% by weight, based on the total amount of the ultraviolet curable adhesive composition for obtaining a double-sided pressure-sensitive adhesive sheet for an image display device. 80% by weight.

Although it does not specifically limit as a photoinitiator contained in the double-sided adhesive sheet for image display apparatuses of this invention, It is preferable to use an acyl phosphine oxide compound. For example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2, 6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide. When irradiating the ultraviolet curable resin after coating with ultraviolet rays to obtain a cured product layer having a cured portion present on the optical substrate side and an uncured portion present on the opposite side of the optical substrate side, an uncured portion 2,4,6-trimethylbenzoyldiphenylphosphine oxide is particularly preferable from the viewpoint of the ease of formation of the resin and the transparency of the cured resin layer.

Other photopolymerization initiators include 1-hydroxycyclohexyl phenyl ketone (Irgacure 184; manufactured by BASF), 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propanol oligomer (Esacure ONE; Lambarti 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one (Irgacure 2959; manufactured by BASF), 2-hydroxy-1- {4 -[4- (2-Hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one (Irgacure 127; manufactured by BASF), 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651; manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl- Lopan-1-one (Darocur 1173; manufactured by BASF), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Irgacure 907; manufactured by BASF), oxy-phenyl-acetate Mixture of tic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl ester and oxy-phenyl-acetic acid 2- [2-hydroxy-ethoxy] -ethyl ester (Irgacure 754; manufactured by BASF) 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, isopropylthioxanthone, α-hydroxy And ketone-based polymers.
Among them, in the double-sided pressure-sensitive adhesive sheet for image display device of the present invention, since volatilization is suppressed even when heated to obtain the sheet, an α-hydroxyketone polymer (manufactured by ESACURE, KIP150) is used. It is preferable to use it.

In the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention, these photopolymerization initiators can be used alone or in a mixture of two or more. The weight ratio of the photopolymerization initiator in the photocurable resin composition for obtaining the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is usually 0.2 to 5% by weight, preferably 0.3 to 3% by weight. . When it is more than 5% by weight, when obtaining a cured product layer having a cured part and an uncured part on the side opposite to the optical substrate side, the uncured part cannot be formed or the transparency of the resin cured product layer is low. There is a risk of getting worse.

Furthermore, it is used in combination with accelerators such as tertiary amines such as triethanolamine and methyldiethanolamine, and benzoic acid derivatives such as N, N-dimethylaminobenzoic acid ethyl ester and N, N-dimethylaminobenzoic acid isoamyl ester. can do. As the addition amount of these accelerators, an amount of 100% by weight or less is added to the photopolymerization initiator as necessary.

The double-sided pressure-sensitive adhesive sheet for an image display device of the present invention can contain, in addition to the (meth) acrylate and the photopolymerization initiator, the following photopolymerization initiation assistant, additives described below, and the like. The content ratio of the other components with respect to the total amount of the ultraviolet curable adhesive composition of the present invention is a balance obtained by subtracting the total amount of the (meth) acrylate and the photopolymerization initiator from the total amount. Specifically, the total amount of the other components is 0 to 74% by weight, preferably 5 to 70% by weight, based on the total amount of the ultraviolet curable adhesive composition for obtaining the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention. %.

Furthermore, amines that can serve as photopolymerization initiation assistants can be used in combination with the above photopolymerization initiator. Examples of amines that can be used include benzoic acid 2-dimethylaminoethyl ester, dimethylaminoacetophenone, p-dimethylaminobenzoic acid ethyl ester, and p-dimethylaminobenzoic acid isoamyl ester. When a photopolymerization initiation aid such as the amine is used, the content in the adhesive resin composition for obtaining the double-sided pressure-sensitive adhesive sheet for image display device of the present invention is usually 0.005 to 5% by weight, preferably 0.01 to 3% by weight.

The double-sided pressure-sensitive adhesive sheet for the image display device of the present invention includes an antioxidant, an organic solvent, a silane coupling agent, a polymerization inhibitor, a leveling agent, an antistatic agent, a surface lubricant, a fluorescent whitening agent, light as necessary. You may add additives, such as a stabilizer (for example, hindered amine compound etc.) and a filler.

Specific examples of the antioxidant include, for example, BHT, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine Pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-t-butyl- 4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3-t -Butyl-5-methyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, , N-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t -Butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, octylated diphenylamine, 2,4-bis [(octylthio) methyl-O-cresol Isooctyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], dibutylhydroxytoluene and the like.

Specific examples of the organic solvent include alcohols such as methanol, ethanol and isopropyl alcohol, dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran, dioxane, toluene, xylene and the like.

Specific examples of the silane coupling agent include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxy) (Cyclohexyl) ethyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, γ-mercapropropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyltrimethoxysilane, 3 -Aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, 3-methacryloxypropyltrimethoxysilane , Silane coupling agents such as chloropropylmethyldimethoxysilane and 3-chloropropyltrimethoxysilane; isopropyl (N-ethylaminoethylamino) titanate, isopropyl triisostearoyl titanate, titanium di (dioctyl pyrophosphate) oxyacetate, Titanium coupling agents such as tetraisopropyldi (dioctylphosphite) titanate, neoalkoxytri (pN- (β-aminoethyl) aminophenyl) titanate; Zr-acetylacetonate, Zr-methacrylate, Zr-propionate, Neoalkoxy zirconate, neoalkoxy tris neodecanoyl zirconate, neoalkoxy tris (dodecanoyl) benzenesulfonyl zirconate, neoalkoxy tris Ethylene-aminoethyl) zirconate, neoalkoxy tris (m-aminophenyl) zirconate, ammonium zirconium carbonate, Al- acetylacetonate, Al- methacrylate, zirconium or the like Al- propionate, or aluminum coupling agent, and the like.

Specific examples of the polymerization inhibitor include paramethoxyphenol and methylhydroquinone.

Specific examples of the light stabilizer include, for example, 1,2,2,6,6-pentamethyl-4-piperidyl alcohol, 2,2,6,6-tetramethyl-4-piperidyl alcohol, 1,2,2, 6,6-pentamethyl-4-piperidyl (meth) acrylate (LA-82, manufactured by ADEKA Corporation), tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3 4-butanetetracarboxylate, tetrakis (2,2,6,6-totramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5.5] Unde Mixed ester with decanoic acid bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1-undecanoxy-2,2,6,6-tetramethylpiperidine-4- Yl) carbonate, 2,2,6,6, -tetramethyl-4-piperidyl methacrylate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6, 6-pentamethyl-4-piperidyl) sebacate, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 1- [2- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethyl Peridine, 1,2,2,6,6-pentamethyl-4-piperidinyl-methacrylate, bis (1,2,2,6,6-pentamethyl-4-piperidinyl) [[3,5-bis (1,1 -Dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, decanedioic acid bis (2,2,6,6-tetramethyl-1 (octyloxy) -4-piperidinyl) ester, 1,1-dimethylethyl Reaction product of hydroperoxide and octane, N, N ′, N ″, N ″ ′-tetrakis- (4,6-bis- (butyl- (N-methyl-2,2,6,6-tetramethylpiperidine- 4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine, dibutylamine 1,3,5-triazine N, N′-bis (2,2,6 6- Polycondensate of tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine, poly [[6- (1,1,3 , 3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2, 6,6-tetramethyl-4-piperidyl) imino]], dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol polymer, 2,2,4,4- Tetramethyl-20- (β-lauryloxycarbonyl) ethyl-7-oxa-3,20-diazadispiro [5 · 1 · 11 · 2] heneicosan-21-one, β-alanine, N,-(2,2, 6,6-tet Lamethyl-4-piperidinyl) -dodecyl ester / tetradecyl ester, N-acetyl-3-dodecyl-1- (2,2,6,6-tetramethyl-4-piperidinyl) pyrrolidine-2,5-dione, 2, 2,4,4-tetramethyl-7-oxa-3,20-diazadispiro [5,1,11,2] heneicosan-21-one, 2,2,4,4-tetramethyl-21-oxa-3, 20-diazadicyclo- [5,1,11,2] -heneicosane-20-propanoic acid dodecyl ester / tetradecyl ester, propanedioic acid, [(4-methoxyphenyl) -methylene] -bis (1,2,2 , 6,6-pentamethyl-4-piperidinyl) ester, higher fatty acid ester of 2,2,6,6-tetramethyl-4-piperidinol, 1,3 Hindered amines such as benzenedicarboxamide, N, N′-bis (2,2,6,6-tetramethyl-4-piperidinyl), benzophenone compounds such as octabenzone, 2- (2H-benzotriazole-2 -Yl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- [2-hydroxy-3- (3,4, 5,6-tetrahydrophthalimido-methyl) -5-methylphenyl] benzotriazole, 2- (3-tert-butyl-2-hydroxy-5-methylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy- 3,5-di-tert-pentylphenyl) benzotriazole, methyl 3- (3- (2H-benzotriazole-2-) ) -5-tert-butyl-4-hydroxyphenyl) propionate and polyethylene glycol reaction product, benzotriazole compounds such as 2- (2H-benzotriazol-2-yl) -6-dodecyl-4-methylphenol Benzoates such as 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2- (4,6-diphenyl-1,3,5-triazine-2- Yl) -5-[(hexyl) oxy] phenol and the like, and hindered amine compounds are particularly preferred.

Specific examples of the filler include, for example, crystalline silica, fused silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, titania, talc and the like. Examples thereof include powder or beads obtained by spheroidizing these.

When present in the composition of various additives, the weight ratio of the various additives in the photocurable transparent adhesive composition for obtaining the double-sided pressure-sensitive adhesive sheet for an image display device is preferably 0.01 to 3% by weight. Is 0.01 to 1% by weight, more preferably 0.02 to 0.5% by weight.

The ultraviolet curable adhesive composition for obtaining the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention can be obtained by mixing and dissolving each of the above-mentioned components at room temperature to 80 ° C. It may be removed by operation. In the adhesive resin composition of the present invention, it is preferable to appropriately adjust the blending ratio of the components so that the viscosity at 25 ° C. is in the range of 300 to 15000 mPa · s in view of applicability.

Next, a method for producing a sheet for obtaining a double-sided PSA sheet for an image display device from the ultraviolet curable adhesive composition will be described.
The ultraviolet curable adhesive composition containing the (meth) acrylate (K) and the softening agent component (G) usually further contains the organic solvent. And the said ultraviolet curing adhesive composition is apply | coated to a base material (usually a release film) so that it may become a fixed film thickness, and after drying, a release film is bonded together, and image display with a release film is displayed. An apparatus double-sided sheet can be obtained.
The drying conditions are not particularly limited as long as they are necessary for the solvent to be removed. Conditions for drying (about 1 to 60 minutes) can be used. The sheet thus obtained is in the form in which no solvent is present or a small amount remains. Here, the residual solvent amount is preferably 5000 ppm or less, more preferably 1000 ppm or less, and particularly preferably 100 ppm or less.
Moreover, the kind of release film is not particularly limited, but, for example, a PET film can be used.
The double-sided pressure-sensitive adhesive sheet for an image display device thus obtained has a structure in which the (meth) acrylate in the component is not crosslinked and polymerized, and the (meth) acryloyl group remains as it is and is laminated.

The double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is preferably used for the purpose of producing a touch panel by attaching at least two optical substrates, at least one of which is an optical substrate having a light shielding part.
The curing shrinkage of the cured product of the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is preferably 3.0% or less, and particularly preferably 2.0% or less. Thereby, when the ultraviolet curable adhesive composition is cured, the internal stress accumulated in the resin cured product can be reduced, and the substrate and the layer made of the cured product of the ultraviolet curable adhesive composition can be reduced. It is possible to effectively prevent the interface from being distorted.
In addition, when the substrate such as glass is thin, when the curing shrinkage rate is large, since the warpage during curing becomes large, the display performance is greatly adversely affected. Is preferred.

Next, the preferable manufacturing form of the manufacturing process of the optical member using the double-sided adhesive sheet for image display apparatuses of this invention is demonstrated.
In the method for producing an optical member of the present invention, it is preferable that at least two optical substrates are bonded together by the following (Step 1) to (Step 3). If it is determined that sufficient adhesive strength can be secured at the stage of (Process 2), (Process 3) can be omitted.
(Process 1) The process of peeling the single-sided release film of the double-sided adhesive sheet for image display apparatuses with a release film with respect to at least 1 optical base material, and arrange | positioning the double-sided adhesive sheet for image display apparatuses.
(Process 2) The process of peeling off the release film of the remaining single side | surface of the double-sided adhesive sheet for image display apparatuses arrange | positioned at the process 1, and bonding another optical base material.
(Process 3) The process of irradiating an ultraviolet-ray through the optical base material which has a light-shielding part to the double-sided adhesive sheet for image display apparatuses in the bonded optical base material, and hardening this hardened | cured material layer.
A specific embodiment of the method for manufacturing an optical member of the present invention that goes through steps 1 to 3 will be described below by taking as an example the bonding of a liquid crystal display unit and a transparent substrate having a light shielding portion.

(Manufacturing form of image display device)
This method is a method of obtaining an optical member by bonding a liquid crystal display unit and a transparent substrate.
A liquid crystal display unit is a liquid crystal display unit in which a liquid crystal material is sealed between a pair of substrates on which electrodes are formed, and a polarizing plate, a driving circuit, a signal input cable, and a backlight unit are provided.
The transparent substrate is a transparent substrate such as a glass plate, a polymethyl methacrylate (PMMA) plate, a polycarbonate (PC) plate, an alicyclic polyolefin polymer (COP) plate, an acrylic resin, or polyethylene terephthalate. The transparent substrate may be subjected to hard coat treatment or antireflection treatment on one side or both sides.
Here, a transparent substrate having a black frame-shaped light-shielding portion on the surface of the transparent substrate can be suitably used, and the light-shielding portion is formed by applying a tape, applying a paint, or printing. In the present invention, the present invention can be applied to a device that does not have a light shielding portion. However, in the following description of the embodiment, a case where a light shielding portion is provided will be described as a specific example. In the case where the light-shielding part is not provided, “transparent substrate” having the light-shielding part can be read as “transparent substrate”, which can be considered as an example of the case where the light-shielding part is not provided.

(Process 1)
First, after removing the single-sided release film from the double-sided pressure-sensitive adhesive sheet with a double-sided release film, the adhesive surface is applied to the surface of the liquid crystal display unit or the surface where the light-shielding portion of the transparent substrate having the light-shielding portion is formed Deploy.
The film thickness of the double-sided pressure-sensitive adhesive sheet for an image display device is adjusted so that the cured resin layer after bonding is 50 to 500 μm, preferably 50 to 350 μm, more preferably 100 to 350 μm.

(Process 2)
Next, after peeling off the release film of the remaining double-sided pressure-sensitive adhesive sheet for an image display device, a liquid crystal display unit and a transparent substrate having a light-shielding portion are bonded to each other in a facing manner. Bonding can be performed either in air or in vacuum.
Here, in order to prevent bubbles from being generated during bonding, it is preferable to perform bonding in a vacuum.
Bonding can be performed by pressing, pressing, or the like.

(Process 3)
Next, the optical member obtained by bonding the transparent substrate and the liquid crystal display unit is irradiated with ultraviolet rays from the side of the transparent substrate having the light-shielding portion to cure the double-sided pressure-sensitive adhesive sheet for image display devices.
The dose of ultraviolet rays is preferably about 100 ~ 4000mJ / cm ² in accumulated light quantity, particularly preferably 200 ~ 3000mJ / cm ² approximately. The light source used for curing by irradiation with ultraviolet to near ultraviolet light may be any lamp as long as it is a lamp that emits ultraviolet to near ultraviolet light. For example, a low-pressure, high-pressure or ultrahigh-pressure mercury lamp, metal halide lamp, (pulse) xenon lamp, or electrodeless lamp can be used.
In this way, an optical member can be obtained.

The transmittance at 400 nm to 800 nm of the cured product of the double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is preferably 90% or more. This is because when the transmittance is less than 90%, it is difficult for light to pass therethrough and the visibility is lowered when used in a display device.
Further, when the cured product has a high transmittance at 400 to 450 nm, the visibility can be further improved. Therefore, the transmittance at 400 to 450 nm is preferably 90% or more.

The double-sided pressure-sensitive adhesive sheet for an image display device of the present invention can be suitably used as an adhesive for producing an optical member by laminating a plurality of optical substrates.
Examples of the optical substrate used in the method for producing an optical member of the present invention include a transparent plate, a sheet, a touch panel, and a display unit.
In the present invention, the “optical substrate” means both an optical substrate having no light shielding part on the surface and an optical substrate having a light shielding part on the surface. In the production of the optical member of the present invention, preferably, at least one of the plurality of optical base materials used is an optical base material having a light shielding portion.
The position of the light shielding part in the optical substrate having the light shielding part is not particularly limited. As a preferred embodiment, a band-shaped light shielding portion having a width of 0.05 to 20 mm, preferably about 0.05 to 10 mm, more preferably about 0.1 to 6 mm is formed in the peripheral portion of the optical substrate. Is the case. The light-shielding portion on the optical substrate can be formed by attaching a tape, applying a coating or printing.

Various materials can be used as the material of the optical substrate used in the present invention. Specifically, resins such as PET, PC, PMMA, a composite of PC and PMMA, glass, COC, COP, plastic (such as acrylic resin), and the like can be given. As an optical substrate used in the present invention, for example, a transparent plate or sheet, a sheet or transparent plate obtained by laminating a plurality of films or sheets such as polarizing plates, a non-laminated sheet or transparent plate, and a transparent made from inorganic glass Plates (inorganic glass plates and processed products thereof, such as lenses, prisms, ITO glass) and the like can be used. The optical substrate used in the present invention is a laminate composed of a plurality of functional plates or sheets (hereinafter referred to as “functional laminate”) such as a touch panel (touch panel input sensor) or the following display unit in addition to the polarizing plate described above. Also called "body").

Examples of the sheet that can be used as the optical substrate used in the present invention include an icon sheet, a decorative sheet, and a protective sheet. Examples of the plate (transparent plate) that can be used in the method for producing an optical member of the present invention include a decorative plate and a protective plate. As materials for these sheets or plates, those listed as materials for transparent plates can be applied.
Examples of the material of the touch panel surface that can be used as the optical substrate used in the present invention include glass, PET, PC, PMMA, a composite of PC and PMMA, COC, and COP.
The thickness of a plate-like or sheet-like optical substrate such as a transparent plate or a sheet is not particularly limited, and is usually about 5 μm to 5 cm, preferably about 10 μm to 10 mm, more preferably about 50 μm to 3 mm. Is the thickness.

As a preferable touch panel used in the present invention, a plate-shaped or sheet-shaped transparent optical substrate having a light-shielding portion and the functional laminate are attached with a cured product of the ultraviolet curable adhesive composition for a touch panel of the present invention. The combined optical member can be mentioned.
Further, by using a display unit such as a liquid crystal display device as one of the optical substrates and using an optical functional material as the other optical substrate, a display unit with an optical functional material (hereinafter also referred to as a display panel). ) Can be manufactured. Examples of the display unit include display devices such as LCD, EL display, EL illumination, electronic paper, and plasma display in which a polarizing plate is attached to glass. Further, examples of the optical functional material include transparent plastic plates such as acrylic plates, PC plates, PET plates, and PEN plates, tempered glass, and touch panel input sensors.

When used as an adhesive for laminating an optical substrate, it is preferable that the refractive index of the cured product is 1.45 to 1.55 in order to improve the visibility because the visibility of the display image is further improved.
Within the range of the refractive index, the difference in refractive index from the base material used as the optical base material can be reduced, and the light loss can be reduced by suppressing the irregular reflection of light.

The optical member including the display unit knit obtained by the manufacturing method of the present invention and the optical base material having the light shielding portion can be incorporated into an electronic device such as a television, a small game machine, a mobile phone, and a personal computer.

The double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is excellent in flexibility, has high moisture resistance, heat resistance, and light resistance, and fills an air gap in a display device such as a liquid crystal display device, an organic EL display device, or a touch panel image display device It is useful for applications such as agents.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

(Synthesis Example 1)
To a reactor equipped with a reflux condenser, a stirrer, a thermometer, and a temperature control device, GI-2000 manufactured by Nippon Soda Co., Ltd. (iodine value: 12.2, hydroxyl value: 46.8 mg ·) as a hydrogenated polybutadiene glycol compound. 545.99 g (0.23 mol) of KOH / g), 7.19 g (0.0023 mol) of Exenol 3020 (polypropylene glycol, hydroxyl value: 35.9 mg · KOH / g) manufactured by Asahi Glass Co., Ltd. as a diol compound, toluene 208 g was charged and stirred until uniform, and the internal temperature was adjusted to 50 ° C. Subsequently, 61.35 g (0.28 mol) of isophorone diisocyanate was added as a polyisocyanate compound and reacted at 80 ° C. until the target NCO content was reached. Next, 0.37 g of 4-methoxyphenol as a polymerization inhibitor was added and stirred until uniform, and 2-hydroxyethyl produced by Osaka Organic Chemical Co., Ltd. as a (meth) acrylate compound having at least one hydroxyl group. 11.00 g (0.095 mol) of acrylate and 0.20 g of tin octylate as a urethanization reaction catalyst were added and reacted at 80 ° C., where the NCO content was 0.1% or less. To obtain a polyurethane compound (E-1). The weight average molecular weight of the obtained polyurethane compound was 66700.

(Synthesis Example 2)
To a reactor equipped with a reflux condenser, a stirrer, a thermometer, and a temperature control device, GI-2000 manufactured by Nippon Soda Co., Ltd. (iodine value: 12.2, hydroxyl value: 46.8 mg ·) as a hydrogenated polybutadiene glycol compound. 522.50 g (0.22 mol) of KOH / g), 6.88 g (0.0022 mol) of Exenol 3020 (polypropylene glycol, hydroxyl value: 35.9 mg · KOH / g) manufactured by Asahi Glass Co., Ltd. as a diol compound, toluene 73.4 g was charged and stirred until uniform, and the internal temperature was adjusted to 50 ° C. Subsequently, 88.9 g (0.40 mol) of isophorone diisocyanate was added as a polyisocyanate compound and reacted at 80 ° C. until the target NCO content was reached. Next, 0.37 g of 4-methoxyphenol as a polymerization inhibitor was added and stirred until uniform, and 2-hydroxyethyl produced by Osaka Organic Chemical Co., Ltd. as a (meth) acrylate compound having at least one hydroxyl group. 41.80 g (0.36 mol) of acrylate and 0.20 g of tin octylate as a urethanization reaction catalyst were added and reacted at 80 ° C., where the NCO content was 0.1% or less. A polyurethane compound (E-2) was obtained. The weight average molecular weight of the obtained polyurethane compound was 15000.

Example 1
109 parts of E-1 (polyurethane compound) of Synthesis Example 1, 18 parts of Clearon TO-125 (aromatic modified terpene resin) manufactured by Yashara Chemical Co., Ltd., 5 parts of KIP150 (α-hydroxyketone polymer) manufactured by ESACURE 40 parts of toluene Were mixed and dissolved to obtain a resin composition. The resulting resin composition is applied to a comma coater so that the thickness of the resin composition layer after drying is 100 μm on the release-treated surface of a PET film (thickness 50 μm) treated with a silicon release agent. And uniformly dried at 120 ° C. for 3 minutes. After drying, the release treatment surface of the PET film treated with the silicon mold release agent is bonded onto the resin composition layer, and the composition of the present invention (configuration: release) Mold-treated PET / resin composition layer / release-treated PET) resin composition sheet was obtained.

(Example 2)
100 parts of Synthesis Example 1 E-1 (polyurethane compound), 2 parts of Bremer LA (lauryl acrylate) manufactured by NOF Corporation, 18 parts of Clearon M-105 (aromatic modified hydrogenated terpene resin) manufactured by Yashara Chemical Co., Ltd. Nippon Soda Co., Ltd. GI-2000 (1,2-hydrogenated polybutadiene glycol) 5 parts, LAMBSON speed cure TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) 0.4 parts, ESACURE KIP150 ( A resin composition was obtained by mixing and dissolving 2 parts of toluene with 2 parts of an α-hydroxyketone polymer.
The obtained resin composition was applied and dried in the same manner as in Example 1 to obtain a resin composition sheet.

Example 3
100 parts of Synthesis Example 1 E-1 (polyurethane compound), 2 parts of Bremer LA (lauryl acrylate) manufactured by NOF Corporation, 18 parts of Clearon M-105 (aromatic modified hydrogenated terpene resin) manufactured by Yashara Chemical Co., Ltd. JX Nippon Mining & Energy Co., Ltd. (polybutene) 5 parts, LAMBSON speed cure TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) 0.4 parts, ESACURE KIP150 (α-hydroxyketone polymer) Two parts of 42 parts of toluene were mixed and dissolved to obtain a resin composition.
The obtained resin composition was applied and dried in the same manner as in Example 1 to obtain a resin composition sheet.

Example 4
67 parts of E-1 (polyurethane compound) in Synthesis Example 1, 28 parts of E-2 (Polyurethane Compound) in Synthesis Example 2, 2 parts of Bremer LA (lauryl acrylate) manufactured by NOF Corporation, Clearon M manufactured by Yashara Chemical Co., Ltd. -105 (Aromatically modified hydrogenated terpene resin) 18 parts, Nippon Soda Co., Ltd. GI-2000 (1,2-hydrogenated polybutadiene glycol) 5 parts, LAMBSON speed cure TPO (2,4,6-trimethylbenzoyl) Diphenylphosphine oxide) 0.4 part and ESACURE 2 parts KIP150 (α-hydroxyketone polymer) 47 parts toluene were mixed and dissolved to obtain a resin composition.
The obtained resin composition was applied and dried in the same manner as in Example 1 to obtain a resin composition sheet.

Examples 1 to 4 are shown in Table 1 and evaluated as follows.

[Supplement under rule 26 30.06.2015]

(Refractive index measurement)
The resin composition sheet of the present invention was irradiated with ultraviolet rays having an integrated light amount of 3000 mJ / cm ^{2 with} a high-pressure mercury lamp (120 W / cm, ozone-less) through a release-treated PET to cure the resin composition layer.
The refractive index (20 ° C.) of the cured resin layer was measured with RX-7000CX (manufactured by ATAGO).

(Rigidity measurement)
The resin composition sheet of the present invention was irradiated with ultraviolet rays having an integrated light amount of 3000 mJ / cm ^{2 with} a high-pressure mercury lamp (120 W / cm, ozone-less) through a release-treated PET to cure the resin composition layer.
The rigidity (30 ° C.) of the cured resin layer was measured with ARES (TA Instruments).

(Transmittance measurement)
The release treatment PET of the resin composition sheet of the present invention was peeled off and bonded to a glass plate having a thickness of 1 mm (configuration: 1 mm glass plate / resin composition layer / 1 mm glass plate) to prepare a test piece.
The resin composition layer was cured by irradiating the prepared test piece with ultraviolet rays through a glass with a high-pressure mercury lamp (120 W / cm, ozone-less) with an integrated light amount of 3000 mJ / cm 2.
The transmittance of the obtained resin cured test piece was measured with a spectrophotometer UV-3600 (manufactured by Shimadzu Corporation). As a result, the transmittance at 380 nm to 780 nm was 95% or more.

(Haze measurement)
The release treatment PET of the resin composition sheet of the present invention was peeled off and bonded to a glass plate having a thickness of 1 mm (configuration: 1 mm glass plate / resin composition layer / 1 mm glass plate) to prepare a test piece.
The resin composition layer was cured by irradiating the prepared test piece with ultraviolet rays having a cumulative light amount of 3000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (120 W / cm, ozone-less).
The haze value of the obtained resin cured test piece was measured with a haze meter TC-HIIIDPK (manufactured by Tokyo Denshoku). As a result, the haze value was 0.5 or less and it was transparent.

(Adhesion test)
The release-treated PET on one side of the resin composition sheet of the present invention was peeled off, bonded to a 100 μm COP film (manufactured by Nippon Zeon Co., Ltd.), and cut into a 25 mm width strip. Half of the cut strip-shaped film is peeled off from the other release-treated PET, and bonded to a glass plate. From the glass plate side, UV light with an integrated light intensity of 3000 mJ / cm ² is irradiated with a high-pressure mercury lamp (120 W / cm, ozone-less) The composition layer was cured. The obtained resin cured test pieces were subjected to an adhesion test (180 ° peeling, peeling speed 300 mm / min) using EZ-Test (manufactured by Shimadzu Corporation).

(durability)
The release treatment PET of the resin composition sheet of the present invention is peeled off and bonded to a glass plate having a thickness of 1 mm (configuration 1: 1 mm glass plate / resin composition layer / 1 mm glass plate) (configuration 2: 1 mm glass plate / resin). Composition layer / polarizing film / acrylic adhesive layer / 1 mm glass plate) A test piece was prepared.
The resin composition layer was cured by irradiating the prepared test piece with ultraviolet rays having a cumulative light amount of 3000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (120 W / cm, ozone-less).
Using the obtained resin cured test piece, an 85 ° C. heat resistance test and a 60 ° C. 90% RH wet heat resistance test were conducted for 100 hours. As a result, the resin cured product test piece after completion of the durability test was visually confirmed, but there was no peeling from the glass plate and the polarizing film.

From the above results, it was confirmed that the double-sided pressure-sensitive adhesive sheet for image display device of the present invention has high transmittance, low haze value, and excellent adhesion, heat resistance, and moist heat resistance.

Although the invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application (2014-120621) filed on June 11, 2014 and a Japanese patent application (2015-112948) filed on June 3, 2015. The whole is incorporated by reference. Also, all references cited herein are incorporated as a whole.

The double-sided pressure-sensitive adhesive sheet for an image display device of the present invention is useful as an optical application member because of its high transparency and excellent adhesion and durability. Furthermore, the resin composition sheet of the present invention is useful as an adhesive for bonding a transparent display substrate.

Claims

At least one (meth) acrylate (K) selected from the group consisting of urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton or (meth) acrylate having a butadiene skeleton, and a softener component (G) A double-sided pressure-sensitive adhesive sheet for an image display device, comprising:
At least one (meth) acrylate (K) selected from the group consisting of urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, or (meth) acrylate having a butadiene skeleton, softener component (G) A double-sided pressure-sensitive adhesive sheet for an image display device, obtained by drying an ultraviolet curable resin composition containing
The (meth) acrylate is urethane (meth) acrylate, and the urethane (meth) acrylate is obtained by reacting the compound (A), the compound (B), the compound (C) and the compound (D) shown below. It is a polyurethane compound (E), The double-sided adhesive sheet for image display apparatuses of Claim 1 or Claim 2 characterized by the above-mentioned.
Compound (A): Hydrogenated polybutadiene polyol compound Compound (B): Polyisocyanate compound Compound (C): (Meth) acrylate compound having at least one hydroxyl group Compound (D): Diol compound other than compound (A)
A double-sided pressure-sensitive adhesive sheet for an image display device comprising the polyurethane compound (E) according to claim 3, wherein the hydrogenated polybutadiene polyol compound (A) has an iodine value of 20 or less.
The double-sided pressure-sensitive adhesive sheet for an image display device comprising the polyurethane compound (E) according to claim 3 or 4, wherein the polyisocyanate compound (B) is an aliphatic diisocyanate compound.
The polyurethane compound (E) according to any one of claims 3 to 5, wherein the (meth) acrylate compound (C) having at least one hydroxyl group is 2-hydroxyethyl (meth) acrylate. A double-sided pressure-sensitive adhesive sheet for image display devices.
The diol compound (D) other than the compound (A) is a polyether polyol, and the polyurethane compound (E) according to any one of claims 3 to 6 is contained. .
A double-sided pressure-sensitive adhesive sheet for an image display device, comprising the polyurethane compound (E) according to any one of claims 1 to 7 and a polymerizable compound (F) other than (E).
The double-sided image display device according to any one of claims 1 to 8, wherein the softener component (G) includes one or both of a hydroxyl group-containing polymer and a terpene resin. Adhesive sheet.
A cured product obtained by irradiating the double-sided pressure-sensitive adhesive sheet for image display device according to any one of claims 1 to 9 with active energy rays.
A touch panel comprising the double-sided pressure-sensitive adhesive sheet for an image display device according to any one of claims 1 to 9.
At least one (meth) acrylate (K) or softener component (G) selected from the group consisting of urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, or (meth) acrylate having a butadiene skeleton A double-sided pressure-sensitive adhesive sheet for an image display device, comprising:
At least one (meth) acrylate (K) selected from the group consisting of urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, or (meth) acrylate having a butadiene skeleton, softener component (G) And a double-sided pressure-sensitive adhesive sheet for an image display device, which contains a solvent.
An image display device is obtained by laminating an optical substrate through the following steps 1 and 2 with the double-sided pressure-sensitive adhesive sheet for an image display device according to any one of claims 1 to 9 and 12 to 13. Manufacturing method of display device.
(Process 1) The process of peeling the single-sided release film of the double-sided adhesive sheet for image display apparatuses with a release film with respect to at least 1 optical base material, and arrange | positioning the double-sided adhesive sheet for image display apparatuses.
(Process 2) The process of peeling off the release film of the remaining single side | surface of the double-sided adhesive sheet for image display apparatuses arrange | positioned at the process 1, and bonding another optical base material.
An image display device is obtained by laminating an optical substrate through the following steps 1 to 3 with the double-sided pressure-sensitive adhesive sheet for an image display device according to any one of claims 1 to 9 and 12 to 13. Manufacturing method of display device.
(Process 1) The process of peeling the single-sided release film of the double-sided adhesive sheet for image display apparatuses with a release film with respect to at least 1 optical base material, and arrange | positioning the double-sided adhesive sheet for image display apparatuses.
(Process 2) The process of peeling off the release film of the remaining single side | surface of the double-sided adhesive sheet for image display apparatuses arrange | positioned at the process 1, and bonding another optical base material.
(Process 3) The process of irradiating an ultraviolet-ray through the optical base material which has a light-shielding part to the double-sided adhesive sheet for image display apparatuses in the bonded optical base material, and hardening this hardened | cured material layer.