JP2012207055A - Foil-like adhesive for optical use and adhesive sheet for optical use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foil-like adhesive for optical use, which has ultraviolet absorbability and is prevented from inhibiting the crosslink by an ultraviolet absorbing agent; and to provide an adhesive sheet for optical use.SOLUTION: The adhesive sheet 1A for optical use includes: a peeling sheet 12; an adhesive layer 11 laminated on a peeling surface of the peeling sheet 12; and a base material 13 laminated on the adhesive layer 11. The adhesive layer 11 is configured by crosslinking: an adhesive component that contains a hydroxy group; a crosslinking agent reacting with the hydroxy group; and the ultraviolet absorbing agent that does not have the hydroxy group, wherein the adhesive layer is made from the foil-like adhesive for optical use, which then has light transmittance of 10% or lower at wavelength of 350 nm.

Description

  The present invention relates to an optical foil-like pressure-sensitive adhesive and an optical pressure-sensitive adhesive sheet used for optical display panels and the like.

  In flat panel displays such as a liquid crystal display (LCD), a plasma display panel (PDP), and electronic paper, films having various functions are used by being laminated with an adhesive. The adhesive used here has not only performance such as high adhesion to the adherend, high light transmittance and low haze, but also no change in the hue of the adhesive even when it is put into a wet heat resistance test. Performance such as absence of physical changes such as foaming of the agent is required.

  As an adhesive, it is desirable not to contain carboxylic acid depending on the kind of adherend to be attached. If the adherend is a metal mesh, indium tin oxide (ITO), etc., and the adhesive contains carboxylic acid, the carboxylic acid corrodes the metal, and the color changes to the metal mesh and the adhesive layer in contact with the metal mesh. May occur. Therefore, the functional group of the pressure-sensitive adhesive to be reacted with the crosslinking agent is desirably a hydroxyl group, and the crosslinking agent is desirably a polyfunctional isocyanate-based crosslinking agent that can react even if the functional group of the pressure-sensitive adhesive is a hydroxyl group.

  On the other hand, color filters, fluorescent dyes, and the like are used for flat panel displays to perform color display, but these are easily deteriorated by ultraviolet rays. For this reason, the color filters, fluorescent dyes, and the like are deteriorated by ultraviolet rays contained in external light (sunlight, fluorescent lamps, etc.), and the color tone may be greatly changed. Therefore, an ultraviolet absorber is used in order to suppress deterioration of the color filter, the fluorescent dye, and the like due to the ultraviolet rays of outside light, and this ultraviolet absorber is generally added to the pressure-sensitive adhesive layer.

  The pressure-sensitive adhesive layer containing an ultraviolet absorber is located between the display surface on which external light is incident and a color filter, fluorescent dye, etc., and absorbs ultraviolet rays to suppress deterioration of the color filter, fluorescent dye, etc. . If the ultraviolet light absorption performance is 10% or less in the light transmittance in the region of 350 nm or less, it is possible to suppress the deterioration of the color filter and the fluorescent dye.

  In general, ultraviolet absorbers such as benzophenone, benzotriazole, and triazine are used as the ultraviolet absorber having the above performance (Patent Documents 1 to 3).

JP 2009-62411 A JP 2007-316336 A JP 2010-98073 A

  However, all of the above UV absorbers have hydroxyl groups. Therefore, when the ultraviolet absorber coexists with the isocyanate-based crosslinking agent, the hydroxyl group of the ultraviolet absorber reacts with the isocyanate group of the crosslinking agent, and the reaction between the hydroxyl group of the pressure-sensitive adhesive and the isocyanate group of the crosslinking agent is inhibited. Thereby, the crosslinking degree of an adhesive, ie, a gel fraction, falls compared with the adhesive which has not added the ultraviolet absorber. Since the amount of the ultraviolet absorber to be added varies widely depending on the application used, it has been difficult to predict how much it will reduce the gel fraction of the adhesive. For this reason, an adhesive having desired characteristics may not be obtained due to a decrease in the gel fraction only by adding an ultraviolet absorber to an adhesive having no known ultraviolet absorber. Specifically, due to a decrease in gel fraction, adhesive properties such as adhesive strength, holding power, and tack may vary, and problems such as foaming may occur in durability tests.

  The present invention has been made in view of such a situation, and provides an optical foil-like pressure-sensitive adhesive and an optical pressure-sensitive adhesive sheet that have ultraviolet absorptivity and in which inhibition of crosslinking by the ultraviolet absorber is suppressed. For the purpose.

  In order to achieve the above object, first, the present invention crosslinks a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive component containing a hydroxyl group, a crosslinking agent capable of reacting with the hydroxyl group, and an ultraviolet absorber having no hydroxyl group. Thus, an optical foil-like pressure-sensitive adhesive having a light transmittance at a wavelength of 350 nm of 10% or less is provided (Invention 1).

  The optical foil-like pressure-sensitive adhesive according to the invention (Invention 1) has an ultraviolet absorptivity by using an ultraviolet absorber having no hydroxyl group, and inhibition of crosslinking caused by the ultraviolet absorber is suppressed. It will be.

  In the said invention (invention 1), it is preferable that the said ultraviolet absorber which does not have a hydroxyl group is a cyanoacrylate type ultraviolet absorber (invention 2).

  In the above invention (Invention 2), the cyanoacrylate-based ultraviolet absorber is at least selected from ethyl-2-cyano-3,3-diphenyl acrylate and 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate. One type is preferred (Invention 3).

  In the said invention (invention 1-3), it is preferable that the adhesion component containing the said hydroxyl group contains a (meth) acrylic acid ester-type copolymer (invention 4).

  In the said invention (invention 4), it is preferable that the said (meth) acrylic acid ester-type copolymer is a polymer formed by superposing | polymerizing the monomer which has a hydroxyl group (invention 5).

  In the said invention (invention 1-5), it is preferable that the crosslinking agent which can react with the said hydroxyl group is an isocyanate type crosslinking agent (invention 6).

  In the said invention (invention 4-6), it is preferable that the said (meth) acrylic-ester type | system | group copolymer is a polymer formed by superposing | polymerizing the monomer which has an amino group (invention 7).

  In the said invention (invention 1-7), it is preferable that the said optical foil-like adhesive contains an amino compound (invention 8).

  In the said invention (invention 1-8), it is preferable to contain further the at least 1 sort (s) of near-infrared absorber chosen from the group which consists of a phthalocyanine type compound, an immonium type compound, a thiol complex type compound, and a cesium tungsten oxide type compound. (Invention 9).

  In the said invention (invention 1-9), it is preferable to contain the benzotriazole type | system | group antirust agent further (invention 10).

  In the said invention (invention 1-10), it is preferable that the storage elastic modulus in 23 degreeC is 0.05-0.25 MPa (invention 11).

  2ndly, this invention is an optical adhesive sheet provided with the base material and the adhesive layer, Comprising: The said adhesive layer consists of the said optical foil-like adhesive (Invention 1-11), It is characterized by the above-mentioned. An optical pressure-sensitive adhesive sheet is provided (Invention 12).

  In the said invention (invention 12), it is preferable that the said base material is an optical member (invention 13).

  Third, the present invention is an optical pressure-sensitive adhesive sheet comprising two release sheets and an adhesive layer sandwiched between the release sheets so as to be in contact with the release surfaces of the two release sheets, The pressure-sensitive adhesive layer provides an optical pressure-sensitive adhesive sheet comprising the optical foil-like pressure-sensitive adhesive (Invention 1 to 11) (Invention 14).

  The optical foil-like pressure-sensitive adhesive and the pressure-sensitive adhesive for the optical pressure-sensitive adhesive sheet according to the present invention have ultraviolet absorptivity, and inhibition of crosslinking due to the ultraviolet absorber is suppressed.

It is sectional drawing of the optical adhesive sheet which concerns on the 1st Embodiment of this invention. It is sectional drawing of the optical adhesive sheet which concerns on the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
[Optical foil adhesive]
The optical foil-like pressure-sensitive adhesive according to this embodiment (hereinafter sometimes referred to simply as “foil-like pressure-sensitive adhesive”) does not have a hydroxyl group-containing pressure-sensitive adhesive component, a crosslinking agent capable of reacting with a hydroxyl group, and a hydroxyl group. A pressure-sensitive adhesive composition containing an ultraviolet absorber is crosslinked.

  There are no particular limitations on the pressure-sensitive adhesive component containing a hydroxyl group, and acrylic, rubber-based, silicone-based, polyurethane-based, polyester-based pressure-sensitive adhesives that contain a hydroxyl group can be used. Of these, acrylic adhesives are preferred.

  Examples of the acrylic pressure-sensitive adhesive include those containing a (meth) acrylic acid ester-based copolymer. In this specification, (meth) acrylic acid ester means both acrylic acid ester and methacrylic acid ester. The same applies to other similar terms. (Cyclo) alkyl means a concept including cycloalkyl as alkyl.

  The (meth) acrylic acid ester-based copolymer includes (meth) acrylic acid (cyclo) alkyl ester having a (cyclo) alkyl group having 1 to 20 carbon atoms and a monomer having a reactive functional group (reactive functional group). Group-containing monomer), a monomer having a reaction-catalytic functional group that is optionally used (reaction-catalytic group-containing monomer), and another monomer that does not have a reactive functional group and a reaction-catalytic functional group that are optionally used A copolymer is preferred.

  Examples of the (cyclo) alkyl (meth) acrylic acid (cyclo) alkyl ester having 1 to 20 carbon atoms in the (cyclo) alkyl group include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, ( N-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, ( Examples include n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

  Examples of the reactive functional group-containing monomer include a monomer having a hydroxyl group in the molecule (hydroxyl group-containing monomer), a monomer having a carboxyl group in the molecule (carboxyl group-containing monomer), and the like. The (meth) acrylic acid ester copolymer is preferably a polymer obtained by polymerizing a hydroxyl group-containing monomer.

  The hydroxyl group is excellent in reactivity with a crosslinking agent capable of reacting with the hydroxyl group, and unlike the carboxyl group, the hydroxyl group does not rust the metal even when the pressure-sensitive adhesive contacts the metal. Even when it contains, the color of the dye is not changed.

  The carboxyl group has an action that the optical foil-like pressure-sensitive adhesive easily corrodes the metal when the substrate or adherend of the optical foil-like pressure-sensitive adhesive has a metal. Therefore, it is preferable not to include a carboxyl group-containing monomer as the reactive functional group-containing monomer of the (meth) acrylic acid ester copolymer.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meth And (meth) acrylic acid hydroxyalkyl esters such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth) acrylate. These may be used alone or in combination of two or more.

  Examples of the carboxyl group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid.

  Examples of the reaction catalytic group-containing monomer include a monomer having an amino group in the molecule (amino group-containing monomer) and a monomer having an acrylamide group in the molecule (acrylamide group-containing monomer). Since the reaction catalytic functional group acts as a catalyst for the reaction between the hydroxyl group and the crosslinking agent capable of reacting with the hydroxyl group, the (meth) acrylic acid ester copolymer is obtained by polymerizing the reaction catalytic group-containing monomer. It is preferable that it is a polymer. Among these reaction-catalytic group-containing monomers, amino group-containing monomers having a strong catalytic action are preferable. Therefore, the (meth) acrylic acid ester-based copolymer is a polymer obtained by polymerizing amino group-containing monomers. It is particularly preferred.

  Examples of the amino group-containing monomer include a secondary amino group such as (meth) acrylic acid ester having a primary amino group such as aminoethyl (meth) acrylate and n-butylaminoethyl (meth) acrylate ( (Meth) acrylic acid ester, (meth) acrylic acid N, N-dimethylaminoethyl, (meth) acrylic acid N, N-dimethylaminopropyl, and other (meth) acrylic acid esters having a tertiary amino group. These may be used alone or in combination of two or more. The action as the above catalyst is higher for (meth) acrylic acid ester having a tertiary amino group, but can be appropriately selected and used depending on the purpose. Since the (meth) acrylic acid ester having a primary amino group or a secondary amino group has an active hydrogen group, it itself acts as a reactive functional group-containing monomer.

  Examples of the acrylamide group-containing monomer include acrylamide and methacrylamide.

  Examples of the other monomer having no reactive functional group and no reactive catalytic functional group include (meth) acrylic acid ester having an aromatic ring such as phenyl (meth) acrylate, vinyl acetate, and styrene. These may be used alone or in combination of two or more.

  The content of the (meth) acrylic acid (cyclo) alkyl ester having 1 to 20 carbon atoms in the (cyclo) alkyl group in the (meth) acrylic acid ester copolymer is preferably in the range of 50 to 100% by mass. By making the content of the (meth) acrylic acid (cyclo) alkyl ester having 1 to 20 carbon atoms in the (cyclo) alkyl group within such a range, the pressure-sensitive adhesive characteristic peculiar to the acrylic pressure-sensitive adhesive can be expressed. it can. The more preferred content of the (meth) acrylic acid (cyclo) alkyl ester having 1 to 20 carbon atoms of the (cyclo) alkyl group is 70 to 99.9% by mass, and the particularly preferred content is 80 to 99% by mass. is there.

  The content of the reactive functional group-containing monomer in the (meth) acrylic ester copolymer is preferably in the range of 0.01 to 15% by mass. When the content of the reactive functional group-containing monomer is 0.01% by mass or more, crosslinking with the later-described reaction with a crosslinking agent is sufficient, and durability is improved. Moreover, it is preferable for the content of the reactive functional group-containing monomer to be 15% by mass or less since there is no decrease in the suitability for bonding to an adherend such as a metal mesh due to excessively high crosslinkability. Considering durability and suitability for bonding to an adherend, the more preferable content of the reactive functional group-containing monomer is 0.1 to 10% by mass, particularly 1.0 to 5.0% by mass. A range is preferred.

  The content of the reaction-catalytic functional group-containing monomer in the (meth) acrylic acid ester copolymer is preferably in the range of 0.01 to 10% by mass. When the content of the reactive functional group-containing monomer is 0.01% by mass or more, desired reaction catalytic properties are obtained, and the reaction between the reactive functional group-containing monomer and the crosslinking agent efficiently proceeds. Further, if the content of the reaction catalytic functional group-containing monomer is 5.0% by mass or less, the desired adhesive property can be obtained without excessively affecting the properties of the pressure-sensitive adhesive by the reaction catalytic functional group-containing monomer. Easy to obtain. The more preferable content of the reaction catalytic functional group-containing monomer is 0.1 to 5.0% by mass, and the particularly preferable content is 0.1 to 3.0% by mass.

  Further, when both the hydroxyl group-containing monomer and the amino group-containing monomer are contained as the reactive functional group-containing monomer and the reaction catalytic functional group-containing monomer, the preferred content of the hydroxyl group-containing monomer in the (meth) acrylic acid ester copolymer The amount is 0.1 to 10% by mass, particularly 1.0 to 5.0% by mass, and the preferable content of the amino group-containing monomer is 0.01 to 10% by mass, particularly 0.1 to 5% by mass. It is.

  There is no restriction | limiting in particular about the copolymerization form of a (meth) acrylic acid ester type copolymer, Any of a random, a block, and a graft copolymer may be sufficient.

  The molecular weight of the (meth) acrylic acid ester copolymer is preferably 400,000 or more in terms of weight average molecular weight. In addition, the weight average molecular weight in this specification is the value of polystyrene conversion measured by the gel permeation chromatography (GPC) method. When the weight average molecular weight is 400,000 or more, adhesion to the adherend and adhesion durability under high heat and wet heat conditions are sufficient, and it is possible to prevent the occurrence of floating or peeling. Considering adhesion and adhesion durability, the weight average molecular weight is preferably 500,000 or more, particularly preferably 500,000 to 2,000,000, and more preferably 500,000 to 1,000,000.

  The said (meth) acrylic-ester type copolymer may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the optical foil-like pressure-sensitive adhesive according to this embodiment, the pressure-sensitive adhesive component containing a hydroxyl group is crosslinked by a crosslinking agent that can react with the hydroxyl group. Thereby, the retention strength of the obtained adhesive improves and the shape as an adhesive layer is maintained favorable.

  The crosslinking agent that can react with a hydroxyl group also includes a crosslinking agent that can react with a phenolic hydroxyl group. Examples of such crosslinking agents include isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, metal chelate crosslinking agents, and the like. Among them, polyfunctional isocyanate crosslinking agents that react with alcoholic hydroxyl groups. Is preferred.

  The isocyanate-based crosslinking agent contains at least a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate, and the like. , And their biuret bodies, isocyanurate bodies, and adduct bodies that are a reaction product with low molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil.

  Examples of the epoxy crosslinking agent include 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, ethylene glycol diglycidyl. Examples include ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidylaniline, diglycidylamine and the like.

  Examples of the aziridine-based crosslinking agent include diphenylmethane-4,4′-bis (1-aziridinecarboxamide), trimethylolpropane tri-β-aziridinylpropionate, tetramethylolmethanetri-β-aziridinyl. Propionate, toluene-2,4-bis (1-aziridinecarboxamide), triethylenemelamine, bisisophthaloyl-1- (2-methylaziridine), tris-1- (2-methylaziridine) phosphine, And trimethylolpropane tri-β- (2-methylaziridine) propionate.

  Metal chelate crosslinking agents include chelate compounds whose metal atoms are aluminum, zirconium, titanium, zinc, iron, tin, etc., but aluminum chelate compounds are preferred from the viewpoint of performance. Examples of the aluminum chelate compound include diisopropoxy aluminum monooleyl acetoacetate, monoisopropoxy aluminum bis oleyl acetoacetate, monoisopropoxy aluminum monooleate monoethyl acetoacetate, diisopropoxy aluminum monolauryl acetoacetate, diisopropoxy Examples thereof include aluminum monostearyl acetoacetate and diisopropoxy aluminum monoisostearyl acetoacetate.

  The above crosslinking agents capable of reacting with a hydroxyl group may be used alone or in combination of two or more. The amount used is usually 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, particularly preferably 1 to 100 parts by weight of the (meth) acrylic acid ester copolymer having a crosslinking point. -5 parts by mass. If the amount of the crosslinking agent capable of reacting with the hydroxyl group is too small, there is little occurrence of a crosslinking reaction with the reactive functional group contained in the reactive functional group-containing monomer, and the effect of improving the holding power of the adhesive may not be obtained. , May not be enough. If the amount of the crosslinking agent capable of reacting with the hydroxyl group is too large, the unreacted crosslinking agent remains even after the optical foil-like pressure-sensitive adhesive is cured, and the adhesive properties may change over time.

  In order to crosslink the (meth) acrylic acid ester copolymer, heat treatment is usually performed. When performing heat processing, it is preferable that heating temperature is 60-150 degreeC, and it is especially preferable that it is 80-120 degreeC. The heating time is preferably 30 seconds to 3 minutes, particularly preferably 50 seconds to 2 minutes. In addition, this heat processing can also serve as the drying process at the time of volatilizing the dilution solvent etc. of the coating liquid (adhesive coating liquid) of an adhesive composition.

  The optical foil-like pressure-sensitive adhesive according to this embodiment contains an ultraviolet absorber having no hydroxyl group together with the above-described pressure-sensitive adhesive component. By containing the ultraviolet absorber, it is possible to suppress deterioration of the color filter, the fluorescent dye, and the like due to the ultraviolet rays of external light. In addition, if a UV-absorbing agent that does not have a hydroxyl group is used, the UV-absorbing agent and the crosslinking agent react preferentially when a crosslinking agent capable of reacting with a hydroxyl group is used for crosslinking of the adhesive component having a hydroxyl group. The ultraviolet absorber does not hinder the reaction between the hydroxyl group of the adhesive component and the crosslinking agent capable of reacting with the hydroxyl group. Therefore, in the obtained foil-like pressure-sensitive adhesive, inhibition of crosslinking is suppressed.

  By suppressing the inhibition of crosslinking, it becomes easy to obtain an optical foil-like pressure-sensitive adhesive having a desired degree of crosslinking (gel fraction). That is, the gel fraction of a pressure-sensitive adhesive using a pressure-sensitive adhesive component containing a hydroxyl group and a crosslinking agent capable of reacting with a hydroxyl group is adjusted by the amount of the hydroxyl group contained and the amount of the crosslinking agent capable of reacting with a hydroxyl group. be able to. Therefore, first, an adhesive not added with an ultraviolet absorber is designed to have a desired gel fraction, and then an ultraviolet absorber having no hydroxyl group is added without changing the amount of other components added. Since the influence of the ultraviolet absorber having no hydroxyl group on the gel fraction is small, the pressure-sensitive adhesive exhibiting a gel fraction close to the gel fraction of the pressure-sensitive adhesive to which no ultraviolet absorber is added, as described above. Can be easily obtained.

Here, the degree of crosslinking inhibition (%) represented by the following formula is preferably less than 20%, particularly preferably 16% or less, and more preferably 12% or less. By satisfying this numerical value, it is shown that the inhibition of the cross-linking of the foil-like pressure-sensitive adhesive resulting from the addition of the ultraviolet absorber is suppressed, and an optical foil-like pressure-sensitive adhesive having a desired gel fraction is easily obtained.
Cross-linking inhibition (%) = {(Gel fraction of adhesive not added with UV absorber−Gel fraction of adhesive added with UV absorber) / Gel fraction of adhesive without UV absorber} × 100
In addition, the gel fraction of an adhesive is a value at the time of sticking (after curing period progress). Specifically, it refers to the gel fraction after the pressure-sensitive adhesive coating solution is applied to a release sheet, heat-treated, and stored for 7 days in an environment of 23 ° C. and 50% RH (relative humidity). Further, the gel fraction of the pressure-sensitive adhesive not added with the ultraviolet absorber is the gel fraction of the pressure-sensitive adhesive obtained by removing only the ultraviolet absorber from the optical foil-like pressure-sensitive adhesive according to this embodiment.

  It will be described more specifically that the optical foil-like pressure-sensitive adhesive according to this embodiment can easily obtain a desired gel fraction. First, the gel fraction of the pressure-sensitive adhesive layer of Comparative Example 1 described later is 99%, but Examples 1 and 2 and Comparative Examples 2 to 4 are Comparative Example 1 except that different types of ultraviolet absorbers were added. It is the same as the pressure-sensitive adhesive layer. Therefore, the “gel fraction of the pressure-sensitive adhesive without addition of an ultraviolet absorber” in Examples 1 and 2 and Comparative Examples 2 to 4 is the gel fraction of the pressure-sensitive adhesive layer of Comparative Example 1. The crosslinking inhibition degree of Comparative Examples 2 to 4 to which an ultraviolet absorber having a hydroxyl group was added showed a large value of 25% or more, and the gel fraction was greatly reduced in comparison with the adhesive layer of Comparative Example 1. ing. On the other hand, the crosslinking inhibition degree of Example 1 and 2 which added the ultraviolet absorber which does not have a hydroxyl group is as small as 7% and 8%. Therefore, when it is desired to set the gel fraction of the optical foil-like pressure-sensitive adhesive according to this embodiment to a value close to 99%, first, a foil-like pressure-sensitive adhesive not containing an ultraviolet absorber as in Comparative Example 1 is designed, Thereafter, an optical foil-like pressure-sensitive adhesive having a gel fraction not significantly different from 99% can be obtained by adding a UV absorber having no hydroxyl group.

  Although the preferable range of the gel fraction of the optical foil-like pressure-sensitive adhesive according to this embodiment varies depending on the application used, it is usually preferably 1 to 100%, more preferably 5 to 99%. The gel fraction of the foil-like pressure-sensitive adhesive is appropriately adjusted within such a range.

  For example, when the optical foil-like pressure-sensitive adhesive according to this embodiment is desired to have reworkability, a higher gel fraction is preferable. In such a case, the preferable range of the gel fraction is 40 to 100%, more preferably 50 to 99%.

  In addition, for example, when the optical foil-like pressure-sensitive adhesive according to the present embodiment is desired to have a concave-convex followability, the gel fraction is preferably low. In such a case, the preferable range of the gel fraction is 1 to 75%, more preferably 5 to 50%.

  Here, as described above, if the amount of the crosslinking agent capable of reacting with the hydroxyl group is too large, the adhesive properties of the optical foil-like pressure-sensitive adhesive may change over time due to the remaining unreacted crosslinking agent. Therefore, it is desirable to suppress the addition amount of the crosslinking agent that can react with the hydroxyl group to a predetermined amount or less. However, if the amount of the crosslinking agent that can react with a hydroxyl group is suppressed, the crosslinking reaction with the hydroxyl group becomes insufficient. When an ultraviolet absorber containing a hydroxyl group is used for such a foil-like pressure-sensitive adhesive, the reaction of a crosslinking agent that can react with a hydroxyl group is further hindered, and therefore the gel fraction is low. Since the optical foil-like pressure-sensitive adhesive according to this embodiment does not hinder the reaction between the crosslinking agent capable of reacting with a hydroxyl group and the hydroxyl group as described above, for example, when the gel fraction is preferably high as described above, Even if a crosslinking agent capable of reacting with the polymer is not excessively added, the gel fraction of the pressure-sensitive adhesive can be maintained high, and the change in the pressure-sensitive adhesive properties of the optical foil-like pressure-sensitive adhesive over time is easily suppressed.

  As the ultraviolet absorber having no hydroxyl group, a cyanoacrylate-based ultraviolet absorber is preferable. As the cyanoacrylate-based ultraviolet absorber, ethyl-2-cyano-3,3-diphenyl acrylate and 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate are preferable, and they are used alone. Alternatively, two types may be used in combination.

  The optical foil-like pressure-sensitive adhesive according to this embodiment may contain an ultraviolet absorber having a hydroxyl group as long as the effects of the present invention are not impaired. The content is preferably 3% by mass or less, more preferably 1% by mass or less, and particularly preferably not contained.

  The content of the ultraviolet absorber in the optical foil-like pressure-sensitive adhesive according to this embodiment is preferably 1 to 20% by mass, and particularly preferably 2 to 10% by mass. By making content of a ultraviolet absorber into such a range, it will become easy to make the light transmittance of wavelength 350nm of the optical foil-like adhesive which concerns on this embodiment into the range mentioned later.

  The optical foil-like pressure-sensitive adhesive according to this embodiment preferably further contains a near-infrared absorber. By containing the near-infrared absorbing agent, it is possible to prevent the near-infrared rays from leaking from the plasma display panel or the like, and to prevent malfunction of other electric devices.

  Examples of the near-infrared absorber include phthalocyanine compounds, imonium compounds, thiol complex compounds, cesium tungsten oxide compounds, and the like. These near infrared absorbers can be used individually by 1 type or in combination of 2 or more types.

  The content of the near infrared absorber in the optical foil-like pressure-sensitive adhesive according to this embodiment is preferably 0.01 to 5% by mass, and particularly preferably 0.1 to 2% by mass.

  The optical foil-like pressure-sensitive adhesive according to this embodiment preferably further contains a rust inhibitor. By containing the rust preventive agent, for example, when the adhesive comes into contact with the metal mesh or ITO of the electromagnetic shielding film, the metal member such as the metal mesh and the additive, and the metal member such as the metal mesh and the adhesive A change in light transmittance due to an action or the like can be suppressed.

  Examples of the rust preventive include azole compounds, triazole compounds, benzotriazole compounds, thiazole compounds, benzothiazole compounds, imidazole compounds, benzimidazole compounds, phosphorus compounds, amine compounds, and nitrite compounds. Compounds, surfactants, silane coupling agents and the like can be mentioned, among which benzotriazole compounds are preferable. When a benzotriazole-based compound is used, it has a high anti-rust effect on metals and is highly compatible with adhesives.

  The benzotriazole-based compound is not particularly limited, but 1H-tolyltriazole is particularly preferable. The above rust inhibitors may be used alone or in combination of two or more.

  The content of the rust inhibitor in the optical foil-like pressure-sensitive adhesive according to this embodiment is preferably 0.1 to 5% by mass, and particularly preferably 0.3 to 2% by mass. Since the content of the rust inhibitor is within this range, the effect as the rust inhibitor is satisfactorily exhibited and the adhesiveness is not inhibited.

  In addition to the above-described components, the optical foil-like pressure-sensitive adhesive according to this embodiment is a component used for a normal optical foil-like pressure-sensitive adhesive, such as a neon light absorber, a color tone adjusting dye, a silane coupling agent, You may contain antioxidant etc.

  The optical foil-like pressure-sensitive adhesive according to this embodiment may contain an amino compound. An amino compound here means the compound which has an amino group other than the (meth) acrylic acid ester type copolymer formed by superposing | polymerizing the monomer which has the above-mentioned amino group. The amino group of the amino compound can react with the hydroxyl group and the reactive functional group-containing monomer of the (meth) acrylic acid ester copolymer in the same manner as the amino group contained in the (meth) acrylic acid ester copolymer. It acts as a catalyst for the reaction with the crosslinking agent. Examples of the amino compound used in this case include triethylamine and triethylenediamine.

  The optical foil-like pressure-sensitive adhesive according to this embodiment has a light transmittance at a wavelength of 350 nm of 10% or less, preferably 7% or less, and particularly preferably 4% or less. The optical foil-like pressure-sensitive adhesive according to the present embodiment has excellent ultraviolet absorptivity by satisfying such light transmittance, for example, when used for an optical display panel such as a plasma display panel or a liquid crystal display, It is possible to effectively suppress the deterioration of the color filter, the fluorescent dye, and the like due to the ultraviolet light of outside light.

  The optical foil-like pressure-sensitive adhesive according to this embodiment preferably has a storage elastic modulus (G ′) at 23 ° C. of 0.05 to 0.25 MPa, particularly preferably 0.10 to 0.15 MPa. . When the storage elastic modulus (G ′) is 0.05 MPa or more, the pressure-sensitive adhesive is not easily deformed even when subjected to an impact from the outside, and a dent is hardly formed. Further, if the storage elastic modulus (G ′) is 0.25 MPa or less, the followability such as printing, unevenness such as unevenness, or metal mesh can be improved, and bubbles can be prevented from remaining. The storage elastic modulus (G ′) is a value measured by a torsional shear method described later.

  Although the thickness of the optical foil-like pressure-sensitive adhesive according to this embodiment can take various numerical values, it is usually 1 to 200 μm, preferably 2 to 100 μm.

[Optical adhesive sheet]
1 and 2 are cross-sectional views of an optical pressure-sensitive adhesive sheet (hereinafter sometimes simply referred to as “pressure-sensitive adhesive sheet”) according to an embodiment of the present invention. As shown in FIG. 1, the optical pressure-sensitive adhesive sheet 1 </ b> A according to the first embodiment includes, in order from the bottom, a release sheet 12, a pressure-sensitive adhesive layer 11 laminated on the release surface of the release sheet 12, and a pressure-sensitive adhesive layer 11. And a base material 13 laminated on the substrate.

  Further, as shown in FIG. 2, the optical pressure-sensitive adhesive sheet 1B according to the second embodiment is in contact with the two release sheets 12a and 12b and the release surfaces of the two release sheets 12a and 12b. The adhesive layer 11 is sandwiched between two release sheets 12a and 12b. In addition, the release surface of the release sheet in this specification refers to a surface having peelability in the release sheet, and includes both a surface that has been subjected to a release treatment and a surface that exhibits peelability without being subjected to a release treatment. .

  In any of the pressure-sensitive adhesive sheets 1A and 1B, the pressure-sensitive adhesive layer 11 is made of a foil-like pressure-sensitive adhesive formed by crosslinking the above-mentioned pressure-sensitive adhesive material.

  The thickness of the pressure-sensitive adhesive layer 11 is appropriately determined according to the purpose and use location of the pressure-sensitive adhesive sheets 1A and 1B. For example, in the case of a pressure-sensitive adhesive layer used for an optical display panel or the like, 5 to 50 μm, In particular, the thickness is preferably 10 to 30 μm.

  There is no restriction | limiting in particular as the base material 13, All can be used as a base material of a normal optical adhesive sheet. For example, in addition to the desired optical member, glass; polyester film such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, cellulose film such as triacetyl cellulose, polyurethane film, polyurethane acrylate film, polyethylene film, polypropylene film, polyvinyl chloride Plastic films such as films, polyvinylidene chloride films, polyvinyl alcohol films, ethylene-vinyl acetate copolymer films, polystyrene films, polycarbonate films, acrylic resin films, norbornene resin films, cycloolefin resin films, and liquid crystal polymer films; Two or more kinds of laminates can be exemplified. The plastic film may be uniaxially stretched or biaxially stretched.

  As an optical member, for example, a film on which a metal member such as an electromagnetic wave shielding film having a metal mesh is formed, a contrast improving film, an antireflection film, an antiglare film; a polarizing plate (polarizing film), a polarizer, a retardation Examples thereof include a plate (retardation film), a viewing angle compensation film, a brightness enhancement film, a contrast enhancement film, and a liquid crystal polymer film. Since the pressure-sensitive adhesive layer 11 used in the optical pressure-sensitive adhesive sheets 1A and 1B according to the present embodiment hardly corrodes metal, among the above, the film on which the metal member is formed is the base material 13 The effects of the optical pressure-sensitive adhesive sheets 1A and 1B according to this embodiment are preferably exhibited.

  Examples of the metal member include a mesh shape and a foil shape. The material of the metal member may be a single metal, an alloy, or a mixture of a resin or an inorganic material and a metal. Examples of the method for forming the metal member include vapor deposition, sputtering, casting of a metal-containing material, and rolling. Applications of the metal member include electromagnetic wave shielding applications, isotropic conductive applications, anisotropic conductive applications, antistatic applications, gas barrier applications, and the like.

  Although the thickness of the base material 13 changes with kinds, for example in the case of an optical member, it is 10-500 micrometers normally, Preferably it is 50-300 micrometers.

  As the release sheets 12, 12a, 12b, for example, a polyethylene film, a polypropylene film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polybutylene terephthalate film, or the like is used. These crosslinked films are also used. Furthermore, these laminated films may be sufficient.

  The release surface of the release sheet (particularly the surface in contact with the pressure-sensitive adhesive layer 11) is preferably subjected to a release treatment. Examples of the release agent used for the release treatment include alkyd, silicone, fluorine, unsaturated polyester, polyolefin, and wax release agents.

  One of the release sheets 12a and 12b (for example, the release sheet 12a) is preferably a light release type release sheet, and the other (for example, the release sheet 12b) is preferably a heavy release type release sheet. Thus, in order to provide a peeling force difference between the release sheets 12a and 12b, it can be achieved by changing the type of the release agent, performing a release process on one side, and not performing a release process on the other side.

  Although there is no restriction | limiting in particular about the thickness of the peeling sheets 12, 12a, 12b, Usually, it is about 20-150 micrometers.

  In order to manufacture the pressure-sensitive adhesive sheet 1A, a pressure-sensitive adhesive layer 11 is formed by applying a pressure-sensitive adhesive coating solution containing a composition constituting the pressure-sensitive adhesive and, if desired, a diluting solvent to the release surface of the release sheet 12, and performing heat treatment. After the formation, the base material 13 is laminated on the pressure-sensitive adhesive layer 11. Note that the heat treatment conditions are the same as the heat treatment for crosslinking described above.

  Moreover, in order to manufacture the said adhesive sheet 1B, the coating liquid of the composition which comprises the said adhesive is apply | coated to the peeling surface of one peeling sheet 12a (or 12b), a heat processing is performed, and the adhesive layer 11 is applied. Then, the release surface of the other release sheet 12b (or 12a) is overlaid on the pressure-sensitive adhesive layer 11. The concentration / viscosity of the coating solution is not particularly limited as long as it can be coated, and can be appropriately selected according to the situation.

  As a method for applying the coating solution, for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, or the like can be used.

  The pressure-sensitive adhesive sheets 1A and 1B according to the present embodiment can be suitably used for optics, particularly for optical display panels such as plasma display panels and liquid crystal displays. For example, when the pressure-sensitive adhesive sheet 1B is used for adhesion between a glass substrate and a desired film (for example, a PET film on which a layer having a desired function is formed), one release sheet 12a (light release type) from the pressure-sensitive adhesive sheet 1B ) Is peeled off and the adhesive layer 11 exposed and the film are bonded, and then the other release sheet 12b (heavy release type) is peeled off and the exposed adhesive layer 11 and the glass substrate are bonded together. .

  Since the pressure-sensitive adhesive layer 11 used for the pressure-sensitive adhesive sheets 1A and 1B according to the present embodiment hardly corrodes metal, at least one of the adherends to which the pressure-sensitive adhesive sheets 1A and 1B according to the present embodiment are bonded is provided. If the adhesive sheet 1A, 1B is a member having a metal member on the surface to be bonded, the effect is preferably exhibited. If the metal member which a to-be-adhered body has is illustrated, the thing similar to the said metal member of the film in which the metal member is formed which is 1 type of the above-mentioned optical member will be mentioned.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, the release sheet 12 of the adhesive sheet 1A may be omitted, or one of the release sheets 12a and 12b in the adhesive sheet 1B may be omitted.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc. In addition, all the compounding quantities of each component are shown by solid content conversion value.

[Example 1]
Butyl acrylate (BA), methyl acrylate (MA), 2-hydroxyethyl acrylate (HEA) and 2- (dimethylamino) ethyl acrylate (DMAEA) are BA / MA / HEA / DMAEA = 66.5 / 30 Acrylate copolymer (weight average molecular weight: 750,000) obtained by copolymerization at a mass ratio of 3/3 / 0.5 (solid content, hereinafter the same), and xylene diisocyanate crosslinking agent (Soken Chemical Co., Ltd., TD-75) 3.75 parts by mass and an ultraviolet absorber composed of ethyl-2-cyano-3,3-diphenyl acrylate (Cypro Chemical Co., Ltd., SEESORB 501) 10 parts by mass are mixed. Then, it was diluted with methyl ethyl ketone to prepare an adhesive coating solution having a nonvolatile content concentration of 25% by mass.

  The thickness of the adhesive coating solution after drying is 25 μm on the release treatment surface of a release film (SP-PET382150, thickness: 38 μm, manufactured by Lintec Co., Ltd.) obtained by releasing one side of a polyethylene terephthalate film with a silicone resin. Thus, it applied using the knife coater and it dried at 90 degreeC for 60 second, and formed the adhesive layer.

  Next, the pressure-sensitive adhesive layer was bonded to the release surface of a release film (SP-PET 381031H, manufactured by Lintec Co., Ltd.) obtained by releasing one side of a polyethylene terephthalate film with a silicone resin, and 23 ° C., 50% RH (relative humidity). This was cured for 7 days under the above conditions, and this was designated as sample (1) (release film / adhesive / release film). Moreover, the said adhesive layer was bonded to the polyethylene terephthalate (PET) film (Toyobo Co., Ltd. make, PET100A4300), and this was made into the sample (2) (PET film / adhesive / release film).

[Example 2]
Samples (1) and (2) were prepared in the same manner as in Example 1 except that 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate (manufactured by Cypro Kasei Co., Ltd., SEESORB 502) was used as the ultraviolet absorber. did.

Example 3
Samples (1) and (2) were prepared in the same manner as in Example 1 except that a tolylene diisocyanate crosslinking agent (manufactured by Nippon Polyurethane Co., Ltd., Coronate L) was used instead of the isocyanate crosslinking agent.

Example 4
Samples (1) and (2) were prepared in the same manner as in Example 1 except that a hexamethylene diisocyanate crosslinking agent (manufactured by Nippon Polyurethane, Coronate HL) was used instead of the isocyanate crosslinking agent.

[Comparative Example 1]
Samples (1) and (2) were produced in the same manner as in Example 1 except that no ultraviolet absorber was added.

[Comparative Example 2]
Samples (1) and (2) were prepared in the same manner as in Example 1 except that a benzophenone-based ultraviolet absorber (Shiraishi Calcium Co., Ltd., UV-24) was used as the ultraviolet absorber.

[Comparative Example 3]
Samples (1) and (2) were produced in the same manner as in Example 1 except that a benzotriazole-based ultraviolet absorber (manufactured by Ciba Specialty Chemicals, TINUVIN 109) was used as the ultraviolet absorber.

[Comparative Example 4]
Samples (1) and (2) were prepared in the same manner as in Example 1 except that a triazine ultraviolet absorber (manufactured by Ciba Specialty Chemicals, TINUVIN 460) was used as the ultraviolet absorber.

[Test Example 1] (Storage elastic modulus measurement)
The pressure-sensitive adhesive layers obtained in Examples or Comparative Examples were laminated to prepare a cylindrical test piece having a diameter of 8 mm and a thickness of 3 mm, and the storage elastic modulus (G ′) was measured by the torsional shear method under the following conditions. . The results are shown in Table 1.
・ Measuring device: Dynamic viscoelasticity measuring device “DYNAMIC ANALYZER RDAII” manufactured by Rheometric Co.
・ Frequency: 1 Hz
・ Temperature: 23 ℃

[Test Example 2] (Gel fraction measurement)
The pressure-sensitive adhesive sheet of sample (1) obtained in Examples or Comparative Examples was cut into 50 mm × 90 mm, and the pressure-sensitive adhesive layer was wrapped in a polyester mesh (mesh size # 380). Specifically, the release film (SP-PET381031H) is peeled and removed from the sample (1) and adhered to the surface to be the inner surface of the polyester mesh, and then the release film (SP-PET382150) is peeled and removed. A polyester mesh was sealed. The mass of the mesh was reduced and the mass of the adhesive alone was weighed with a precision balance. The mass at this time is M1.

  Next, the pressure-sensitive adhesive wrapped in the polyester mesh was immersed in 200 ml of ethyl acetate solvent at room temperature (23 ° C.) for 48 hours. Thereafter, the pressure-sensitive adhesive was taken out, air-dried for 24 hours in an environment of a temperature of 23 ° C. and a relative humidity of 50%, and further dried in an oven at 80 ° C. for 12 hours. The mass of only the pressure-sensitive adhesive after drying was weighed with a precision balance. The mass at this time is M2. The gel fraction (%) is represented by (M2 / M1) × 100. Table 1 shows the gel fraction results of the pressure-sensitive adhesive added with the UV absorber. In Comparative Example 1, since the adhesive itself was not added with the ultraviolet absorber, the item “gel fraction of the adhesive added with the ultraviolet absorber” does not exist and is described in Table 1. Absent.

  Also, a sample (1) prepared in the same manner as in each Example and Comparative Example except that the ultraviolet absorber was not added was prepared, and the gel fraction of the adhesive without the ultraviolet absorber was set in the same manner as above. Measured. The results are shown in Table 1. The “gel fraction of the pressure-sensitive adhesive with no UV absorber added” in Examples 1 and 2 and Comparative Examples 2 to 4 is the same as the gel fraction of Comparative Example 1.

[Test Example 3] (Calculation of crosslinking inhibition degree)
Based on the gel fraction measured in Test Example 2 for each pressure-sensitive adhesive of Examples and Comparative Examples, the degree of crosslinking inhibition (%) was calculated according to the following formula. The results are shown in Table 1.
Cross-linking inhibition (%) = {(Gel fraction of adhesive not added with UV absorber−Gel fraction of adhesive added with UV absorber) / Gel fraction of adhesive without UV absorber} × 100
In Comparative Example 1, there is no item of “gel fraction of pressure-sensitive adhesive added with UV absorber”, and therefore, the degree of crosslinking inhibition is not described in Table 1.

[Test Example 4] (Light transmittance measurement)
The release film was peeled off from the sample (2) obtained in the examples or comparative examples, and the exposed adhesive layer was attached to soda lime glass (manufactured by Nippon Sheet Glass Co., Ltd.). About this laminated body, the light transmittance of the wavelength of 350 nm was measured using the spectrophotometer (The product made by SHIMADZU, UV-VIS-NIR SPECTROTOPOMETER UV-3600). The results are shown in Table 1.

  From Table 1, it turned out that the adhesive of an Example has the favorable storage elastic modulus and the outstanding ultraviolet absorptivity, and the inhibition of the bridge | crosslinking by addition of a ultraviolet absorber is suppressed. On the other hand, the pressure-sensitive adhesive of Comparative Example 1 had almost no ultraviolet absorptivity, and the pressure-sensitive adhesives of Comparative Examples 2 to 4 were markedly inhibited by crosslinking due to the addition of the UV absorber.

  The optical foil-like pressure-sensitive adhesive and the optical pressure-sensitive adhesive sheet of the present invention are suitable for bonding each layer in an optical display panel such as a plasma display panel or a liquid crystal display.

1A, 1B ... Adhesive sheet 11 ... Adhesive layer 12, 12a, 12b ... Release sheet 13 ... Base material

Claims (14)

A pressure-sensitive adhesive component containing a hydroxyl group, a crosslinking agent capable of reacting with the hydroxyl group, and a pressure-sensitive adhesive composition containing an ultraviolet absorber having no hydroxyl group,
An optical foil-like pressure-sensitive adhesive having a light transmittance of 350% or less at a wavelength of 350 nm.   The optical foil-like pressure-sensitive adhesive according to claim 1, wherein the ultraviolet absorber having no hydroxyl group is a cyanoacrylate-based ultraviolet absorber.   The cyanoacrylate-based ultraviolet absorber is at least one selected from ethyl-2-cyano-3,3-diphenyl acrylate and 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate. The optical foil-like pressure-sensitive adhesive according to claim 2.   The optical foil-like pressure-sensitive adhesive according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive component containing a hydroxyl group contains a (meth) acrylic acid ester-based copolymer.   The optical foil-like pressure-sensitive adhesive according to claim 4, wherein the (meth) acrylic acid ester-based copolymer is obtained by polymerizing a monomer having a hydroxyl group.   The optical foil-like pressure-sensitive adhesive according to claim 1, wherein the crosslinking agent capable of reacting with a hydroxyl group is an isocyanate-based crosslinking agent.   The optical foil-like pressure-sensitive adhesive according to any one of claims 4 to 6, wherein the (meth) acrylic acid ester copolymer is obtained by polymerizing a monomer having an amino group.   The optical foil-like pressure-sensitive adhesive according to any one of claims 1 to 7, wherein the optical foil-like pressure-sensitive adhesive contains an amino compound.   9. The composition according to claim 1, further comprising at least one near-infrared absorber selected from the group consisting of phthalocyanine compounds, imonium compounds, thiol complex compounds, and cesium tungsten oxide compounds. The optical foil-like pressure-sensitive adhesive according to item.   The optical foil-like pressure-sensitive adhesive according to any one of claims 1 to 9, further comprising a benzotriazole-based rust inhibitor.   The optical film-like pressure-sensitive adhesive according to any one of claims 1 to 10, wherein a storage elastic modulus at 23 ° C is 0.05 to 0.25 MPa. An optical pressure-sensitive adhesive sheet comprising a base material and a pressure-sensitive adhesive layer,
The said adhesive layer consists of an optical foil-like adhesive as described in any one of Claims 1-11, The optical adhesive sheet characterized by the above-mentioned.   The optical adhesive sheet according to claim 12, wherein the base material is an optical member. Two release sheets,
An optical pressure-sensitive adhesive sheet comprising an adhesive layer sandwiched between the release sheets so as to be in contact with the release surfaces of the two release sheets,
The said adhesive layer consists of an optical foil-like adhesive as described in any one of Claims 1-11, The optical adhesive sheet characterized by the above-mentioned.

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