TW201817843A - Adhesive composition and adhesive film - Google Patents

Abstract

The present invention provides an adhesive composition and an adhesive film, which have excellent anti-white turbidity property even when the adhesive composition is thickly coated and placed in a high temperature and humidity atmosphere for a long period of time. The adhesive composition contains an acrylic polymer copolymerized by (A) at least one (meth)acrylic acid ester monomer having a C1 to C18 alkyl group, and 0.1-10 parts by weight of (B) at least one hydroxyl group-containing copolymerizable monomer, based on 100 parts by weight of (A). The acrylic polymer has a weight-average molecular weight between 200,000 and 2,000,000 and an acid value of 5.0 or less. The adhesive composition further contains (C) at least one diester compound represented by R1COO-(R3-O)n-CO-R2, wherein each of R1and R2 represents an alkyl group having a carbon number of 4 to 17, R3 represents an alkylene group having a carbon number of 2 to 5, and n represents an integer of 3 to 25; (D) an isocyanate compound; and (E) an antioxidant.

Description

   Adhesive composition and adhesive film   

The present invention provides an adhesive composition and an adhesive film that do not cause white turbidity and have excellent anti-turbidity properties even after being left in a high-temperature and high-humidity environment for a long period of time even when the adhesive layer is thickly applied.

In recent years, in various displays such as a liquid crystal panel and an organic electroluminescence panel, various optical films or protective plates are attached to the front of the display. On the front of the display, for example, a touch panel capable of performing a functional operation of the display by touching the screen with a finger, and an anti-reflection film for preventing external light from being reflected on the surface of the touch panel are attached. By using these films as an optical film for a display, improvement of the operation function of a display and improvement of the image mapping situation are achieved.

In addition, in a portable telephone using a liquid crystal panel as a display, in order to prevent cracks in the liquid crystal panel, a protective plate for absorbing an impact is mounted on the front of the liquid crystal panel with an air layer interposed therebetween. However, recently, in order to reduce weight and thickness, and improve visibility, a thin protective plate is being directly bonded using an adhesive layer without providing an air layer in front of a liquid crystal panel of a mobile phone.

The above-mentioned optical film and protective plate are bonded to the front surface of the display by using an adhesive layer. However, when various optical films are bonded to a display using an adhesive layer, there is a problem that air bubbles are entangled and minute bubbles are generated in the adhesive layer.

In addition, in the performance test of the display performed before shipment of the display device, the endurance test under an environment condition of high temperature and high humidity using an oven must be qualified. However, in the case of bonding an optical film using an adhesive layer having no improvement in white turbidity resistance, there is a problem that the adhesive layer becomes white turbid after taking it out of the oven, thereby impairing the commercial value of the display.

As mentioned above, in order to solve the problem of generating tiny bubbles in the adhesive layer when the optical film is attached to the display using an adhesive tape; or when the durability test is performed on the display under an environment of high temperature and humidity using an oven and the display Various problems have been under way since the problem of white turbidity in the adhesive layer after being taken out of the oven.

For example, Patent Document 1 discloses an adhesive optical film using an adhesive layer, which improves the repair performance when depressions are generated on the surface of the adhesive layer, thereby preventing the inclusion of air bubbles. Specifically, it is a polymer containing an alkyl (meth) acrylate having 7 to 18 carbon atoms and an hydroxyl group-containing monomer containing an alkyl group in a weight ratio of 100: 0.01 to 5, and containing An adhesive layer formed of a crosslinked product of a composition having two or more functional groups that react with a hydroxyl group. A method is described in which an optical film is bonded to a glass by using this adhesive layer (thickness: 20 μm), and then left to stand in a 50 ° C. × 0.05 MPa atmosphere for 5 minutes, and a method for visually confirming the occurrence of micro bubbles in the adhesive layer is described. To check for the presence of bubbles, to prevent the generation of micro bubbles.

In addition, Patent Document 2 discloses a resin composition containing an acrylic derivative, an acrylic derivative polymer, and a polymer for impact absorption necessary for protection of an image display device and the like. Molecular weight cross-linking agent. It is useful for alleviating cracks or stress and impact of an image display panel, and is excellent in transparency.

It is described that a resin sheet formed by using a frame having a depth of 0.5 mm is placed in a high-temperature and high-humidity test tank at 60 ° C and 90% RH for 50 hours, thereby performing a moisture absorption test, and confirming the results by a method of visual evaluation and evaluation. If it is this resin composition, it has few bubbles and is excellent in transparency.

In addition, Patent Document 3 discloses an adhesive layer for an electronic display having excellent moisture and heat resistance. Specifically, an adhesive composition for an electronic display containing a copolymer and / or a mixture of an alkyl (meth) acrylate monomer and a carboxyl group-containing monomer is used. An adhesive composition for an electronic display, further comprising a monomer having an alkyleneoxy group and a (meth) acrylate monomer containing a hydroxyl group.

As a moisture absorption test, a laminated body adhered to a glass plate via an adhesive layer (thickness: 200 μm) laminated on a resin film was left in an environment of 60 ° C. and 90% RH for 120 hours, and then at room temperature ( (25 ° C) for 30 minutes, and then the haze value was measured to determine the transparency of the laminate. According to this adhesive composition, even after being left under high temperature and high humidity, there is less foaming and high transparency can be maintained.

    [Prior technical literature]         [Patent Literature]    

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-262729

Patent Document 2: Japanese Patent Application Laid-Open No. 2008-248221

Patent Document 3: Japanese Patent Laid-Open No. 2008-001739

Conventionally, in order to solve the problem of white turbidity caused by thick coating of an optical adhesive layer after being left in an atmosphere of high temperature and high humidity, a hydroxyl-containing comonomer of an acrylic polymer included in the adhesive composition was increased. Measures for increasing the content ratio of hydrophilic monomers, such as increasing the content ratio of alkoxy-containing monomers, and increasing the content ratio of alkoxy-containing monomers. However, if the amount of the hydrophilic monomer in the acrylic polymer is excessively increased, new problems such as the durability of the adhesive layer, a decrease in the adhesive force, and the like may adversely affect the performance of the actual adhesive layer.

The technical problem of the present invention is to provide an adhesive composition and an adhesive film that do not cause white turbidity and have excellent anti-turbidity properties even after being left in a high-temperature and high-humidity atmosphere for a long time even when the adhesive layer is thickly applied. .

The inventors of the present application conducted intensive research in order to solve the above-mentioned technical problems. As a result, they found that by adding a diester compound to the acrylic adhesive composition, a state in which most hydrophilic groups are dispersed can be formed. The adhesive layer can suppress the phenomenon that the adhesive layer becomes cloudy after being placed in an atmosphere of high temperature and high humidity, thereby completing the invention of the present application.

That is, in the adhesive composition of the present invention, it is avoided to greatly increase the content ratio of the copolymerizable monomer containing a hydroxyl group contained in the acrylic polymer, and instead, it contains a non-copolymerizable compound and a hydrophilic group. A diester compound having a polyalkylene oxide structure. The technical idea of the present invention is to obtain the following adhesive composition by this method: preventing the adhesive layer formed by cross-linking the adhesive composition from reducing the durability and the adhesive force; When the layer is left in a high-temperature and high-humidity atmosphere for a long time, it does not produce white turbidity and has excellent anti-white turbidity performance.

In addition, in order to suppress yellowing (increased b ^* value) of the adhesive layer from being oxidized, the adhesive composition of the present invention contains an antioxidant.

In order to solve the technical problem, the present invention provides an adhesive composition containing an acrylic polymer and a cross-linking agent, characterized in that the acrylic polymer comprises an acid having a weight average molecular weight of 200,000 to 2 million, A copolymer having a value of 5.0 or less, the copolymer being composed of at least one or more kinds of (meth) acrylic acid ester monomers having C1 to C18 with respect to 100 parts by weight of the (A) alkyl group in total, It is copolymerized with at least one or more of (B) a copolymerizable monomer containing a hydroxyl group as a copolymerizable monomer group at a ratio of 0.1 to 10 parts by weight, and the adhesive composition further contains the following formula (1) At least one or more of the (C) diester compounds represented, (D) an isocyanate compound as the crosslinking agent, and (E) an antioxidant selected from the group consisting of a phenol-based antioxidant and a phosphite-based antioxidant. One or more compounds in the oxidant group contain the (E) antioxidant in an amount of 0.01 to 1.0 part by weight based on 100 parts by weight of the acrylic polymer.

R ¹ COO- (R ³ -O) _n -CO-R ² (1)

Among them, R ¹ and R ² each represent an alkyl group having 4 to 17 carbon atoms; R ³ represents an alkylene group having 2 to 5 carbon atoms; and n represents an integer of 3 to 25.

In addition, the weight average molecular weight of the (C) diester compound is 300 to 1200, and the (C) diester is preferably contained in a proportion of 0.1 to 20 parts by weight based on 100 parts by weight of the acrylic polymer. Ester compound.

In addition, in an adhesive layer having a coating thickness of 175 μm formed by crosslinking the adhesive composition, the haze value of the adhesive layer was 1.0% or less, and the adhesive layer was subjected to a temperature of 85 ° C. and 85 ° C. After being left in an atmosphere of% RH for 240 hours, the haze value of the adhesive layer when taken out to a room temperature environment is more than 0.0% and 4.0% or less, and a b ^* value of more than 0.0 and 0.5 or less is preferable.

The (B) hydroxyl-containing copolymerizable monomer is selected from the group consisting of 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate , 2-hydroxyethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide At least one or more of the compound groups are preferred.

In the copolymerizable monomer group, the carboxyl-containing copolymerizable monomer is selected from the group consisting of (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, and 2- (formaldehyde). ) Acryloxyethyl hexahydrophthalic acid, 2- (meth) acryloxypropyl hexahydrophthalic acid, 2- (meth) acryloxyethyl phthalic acid , 2- (meth) acryloxyethyl succinic acid, 2- (meth) acryloxyethyl maleic acid, carboxy polycaprolactone mono (meth) acrylate, 2- (methyl) ) At least one or more of the compound group consisting of acryloxyethyl tetrahydrophthalic acid is preferred.

The adhesive composition further contains, as an antistatic agent, an ionic compound having a melting point of 25 ° C or higher and a solid at a temperature of 25 ° C. The ionic compound is a cationic component selected from the group consisting of pyridinium, imidazolium, osmium, hydrazone, and pyrrole. An ionic compound of one of the cationic groups consisting of pyridinium, guanidinium, ammonium, isouronium, thiouronium, piperidinium, and pyrazolium, relative to 100 parts by weight of the acrylic polymer contains the antistatic agent at a ratio of 0.01 to 5 parts by weight, and the surface resistivity of the adhesive layer formed by crosslinking the adhesive composition is 1.0 × 10 ^{+ 11} Ω / □ or less is preferred.

The (D) isocyanate compound is an addition of an isocyanurate body selected from a hexamethylene diisocyanate compound, an isocyanurate body of an isophorone diisocyanate compound, and an hexamethylene diisocyanate compound. Compounds, adducts of isophorone diisocyanate compounds, biuret bodies of hexamethylene diisocyanate compounds, biuret bodies of isophorone diisocyanate compounds, isocyanurates of toluene diisocyanate compounds Body, isocyanurate body of xylylene diisocyanate compound, isocyanurate body of hydrogenated xylylene diisocyanate compound, adduct of toluene diisocyanate compound, xylylene diisocyanate compound One or more trifunctional isocyanate compounds among an adduct and an adduct of a hydrogenated xylyl diisocyanate compound are contained in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the acrylic polymer. D) An isocyanate compound is preferred.

In addition, the present invention provides an adhesive film characterized in that an adhesive obtained by crosslinking the above-mentioned adhesive composition is laminated on one surface of a resin film.

In addition, the present invention provides an adhesive film, wherein a thickness of the adhesive layer used for bonding a polarizer and an In-cell panel is 5 to 25 μm.

In addition, the present invention provides an adhesive film, wherein a thickness of the adhesive layer of the polarizer and the panel on which one surface of the protective film is a COP film is 5 to 25 μm.

In addition, the present invention provides an optical film for a touch panel, wherein a thickness of the adhesive layer used in the adhesive film is 25 to 250 μm.

In addition, the present invention provides an optical film with an adhesive, wherein an adhesive formed by crosslinking the above-mentioned adhesive composition is laminated on at least one side of the optical film.

According to the present invention, it is possible to provide an adhesive composition and an adhesive film having excellent anti-turbidity properties without generating white turbidity even after being left in a high-temperature and high-humidity atmosphere for a long time even when the adhesive layer is thickly applied.

In addition, since the adhesive layer using the adhesive composition of the present invention contains an antioxidant, yellowing of the adhesive layer due to oxidation can be suppressed (b ^* value increases).

Hereinafter, the present invention will be described based on preferred embodiments.

The adhesive composition of the present invention is an adhesive composition containing an acrylic polymer and a cross-linking agent, wherein the acrylic polymer has a number of carbon atoms with respect to 100 parts by weight of the (A) alkyl group in total. At least one or more of the (meth) acrylic acid ester monomers of C1 to 18, and at least one or more of the (B) copolymerizable monomers containing a hydroxyl group as a copolymerizable monomer group in a ratio of 0.1 to 10 parts by weight An acrylic polymer formed by copolymerization of a copolymer having a weight average molecular weight of 200,000 to 2 million and an acid value of 5.0 or less, and the adhesive composition further contains (C) represented by the following formula (1): ) At least one or more diester compounds, (D) an isocyanate compound as the crosslinking agent, and (E) an antioxidant selected from an antioxidant group consisting of a phenol-based antioxidant and a phosphite-based antioxidant One or more kinds of compounds contain the (E) antioxidant in an amount of 0.01 to 1.0 parts by weight based on 100 parts by weight of the acrylic polymer.

R ¹ COO- (R ³ -O) _n -CO-R ² (1)

Among them, R ¹ and R ² each represent an alkyl group having 4 to 17 carbon atoms; R ³ represents an alkylene group having 2 to 5 carbon atoms; and n represents an integer of 3 to 25.

The adhesive composition of the present invention contains an acrylic polymer as an adhesive polymer. The acrylic polymer is particularly preferably a copolymer containing at least one or more of (A) alkyl (meth) acrylate monomers having C1 to C18 as a main component.

Examples of (A) alkyl (meth) acrylate monomers having 1 to 18 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth) acrylate. , Butyl (meth) acrylate, isobutyl (meth) acrylate, amyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, Isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, (methyl) ) Dodecyl acrylate, tetradecyl (meth) acrylate, cetyl (meth) acrylate, octadecyl (meth) acrylate, and the like. The alkyl group of the (meth) acrylic acid alkyl ester monomer may be any of linear, branched, and cyclic, and may have an aromatic group.

The number of carbon atoms of an alkyl group (aralkyl group) having an aromatic group is calculated by adding the number of carbon atoms of the aromatic group. For example, in the case of benzyl (meth) acrylate, the number of carbon atoms in the alkyl group is the same as the number of carbon atoms in the benzyl group, and is C7.

Examples of the (B) hydroxy-containing copolymerizable monomer include a hydroxy-containing (meth) acrylate type, a hydroxy-containing (meth) acrylamide type, and the like. As these specific examples, it is preferably selected from the group consisting of 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, Compounds) consisting of 2-hydroxyethyl acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide At least one or more of the group.

(B) is preferably contained in a proportion of 0.1 to 10 parts by weight with respect to at least one or more of (1) to 18 (meth) acrylic acid ester monomers having a carbon number of C1 to 18 based on a total of 100 parts by weight of the (A) alkyl group. At least one or more of the hydroxyl-based copolymerizable monomers are copolymerized with at least one or more of the (A) alkyl (meth) acrylate monomers having a carbon number of C1 to 18, more preferably 0.2 to 9.5 parts by weight It is particularly preferred to copolymerize at a ratio of 0.6 to 9.0 parts by weight, and most preferably to copolymerize at a ratio of 1.2 to 8.5 parts by weight.

In the copolymerizable monomer group, a copolymerizable monomer containing a carboxyl group may be further used together. Specific examples of the carboxyl group-containing copolymerizable monomer include those selected from the group consisting of (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, and 2- (meth) acrylic acid. Ethoxyethyl hexahydrophthalic acid, 2- (meth) acrylic ethoxypropyl hexahydrophthalic acid, 2- (meth) acrylic ethoxyethyl phthalic acid, 2- (Meth) acryloxyethyl succinic acid, 2- (meth) acryloxyethyl maleic acid, carboxy polycaprolactone mono (meth) acrylate, 2- (meth) acrylic acid At least one or more of the compound group consisting of oxyethyltetrahydrophthalic acid and the like.

The content of the carboxyl group-containing copolymerizable monomer is preferably adjusted in accordance with the acid value of the acrylic polymer. The acrylic polymer may be a copolymer obtained by copolymerizing a copolymerizable monomer containing a carboxyl group, or may be a copolymer obtained by copolymerizing a copolymerizable monomer containing a carboxyl group. The acid value of the acrylic polymer is preferably 5.0 or less, more preferably 3.0 or less, and most preferably 2.0 or less.

Monomers such as the (A) alkyl group having a carbon number of C1 to C18 (meth) acrylate monomers, (B) a copolymerizable monomer containing a hydroxyl group, and the like constitute an acrylic polymer as an adhesive. Adhesive polymer for the base. The method for preparing the acrylic polymer is not particularly limited, and appropriate polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization can be used. The average molecular weight of the acrylic polymer is preferably within a range of 200,000 to 2 million.

In order to reduce the turbidity of the adhesive layer in an atmosphere of high temperature and high humidity, the adhesive composition of the present invention contains a (C) diester compound. (C) The diester compound is preferably hydrophilic by having a polyalkylene oxide structure. Such a (C) diester compound is a polyalkylene glycol derivative (polyether compound), and the hydroxyl groups at both ends of the polyalkylene glycol are diesterized by an esterification reaction with a saturated fatty acid. Therefore, it does not react with the (D) isocyanate compound and is also excellent in compatibility with the acrylic polymer. The content of the (C) diester compound is not particularly limited, and the (C) diester compound is preferably contained in a proportion of 0.1 to 20 parts by weight, and more preferably 0.2 to 16 parts by weight, based on 100 parts by weight of the acrylic polymer. It is particularly preferably contained at a ratio of 0.6 to 14 parts by weight, and most preferably 1.1 to 12 parts by weight.

The (C) diester compound is preferably a compound represented by the following formula (1).

R ¹ COO- (R ³ -O) _n -CO-R ² (1)

Among them, R ¹ and R ² each represent an alkyl group having 4 to 17 carbon atoms; R ³ represents an alkylene group having 2 to 5 carbon atoms; and n represents an integer of 3 to 25.

R ¹ and R ² may be the same alkyl group or different alkyl groups. Examples of the alkyl group represented by R ¹ or R ² include n-butyl [valerate], isobutyl [3-methylbutyrate], and 1-methylpropyl [2-methylbutyrate Ester], sec-butyl [2-ethylpropanoate], pentyl [hexanoate], 2-methylbutyl [2-methylvalerate], 1-ethylpropyl [2-ethyl Butyrate], hexyl [heptanoate], 1-methylpentyl [2-methylhexanoate], 2-methylpentyl [3-methylhexanoate], 4-methylpentyl [5-methylhexanoate], 2-ethylbutyl [2-ethylvalerate], heptyl [caprylate], 1-ethylpentyl [2-ethylhexanoate] , 2,3-dimethylpentyl [3,4-dimethylhexanoate], 2,4-dimethylpentyl [3,5-dimethylhexanoate], 3,4-di Methylpentyl [4,5-dimethylhexanoate], nonyl [decanoate], undecyl [laurate], tridecyl [myristate], pentadecyl [Palmitate], heptadecyl [stearate], and the like. Here, the names shown in parentheses of [] represent the names of the esters represented by R ¹ COO group or R ² COO group.

R ¹ and R ² are both saturated hydrocarbon groups, and because they are not copolymerized with an acrylic polymer, they are easily distributed evenly in the adhesive composition.

Examples of the alkylene group represented by R ³ include ethylene (-CH ₂ CH _2- ), propylene (-CH ₂ CH (CH ₃ )-), and trimethylene (-CH ₂ CH ₂ CH _2- ), butylene (-CH ₂ CH ₂ CH (CH ₃ )-), tetramethylene (-CH ₂ CH ₂ CH ₂ CH _2- ), isoprene group (-CH ₂ C (CH ₃ ) = CHCH _2- ), pentylene group (-CH ₂ CH ₂ CH ₂ CH (CH ₃ )-), pentamethylene (-CH ₂ CH ₂ CH ₂ CH ₂ CH _2- ) and so on. R ³ may be a saturated alkylene group or an unsaturated alkylene group, and preferably R ³ is a saturated alkylene group. In the case where R ³ is an unsaturated alkylene group, in the -OR ³ -O- structure, 2-butenylene (-CH ₂ in which an unsaturated carbon atom is not bonded to an oxygen atom is preferred) CH = CHCH _2- ) or isoprenyl (-CH ₂ C (CH ₃ ) = CHCH _2- ).

n is a repeating number of an alkyleneoxy group (R ³ -O), and is an integer of 3 to 25. If the value of n is large, hydrophilicity is increased, which is preferable for improving the anti-cloudiness performance under high temperature and high humidity environment conditions. However, if the value of n is too large, there is a possibility of increasing the turbidity of the adhesive layer by absorbing moisture in the atmosphere and the like even without passing through high temperature and high humidity environmental conditions. Therefore, n is preferably 25 or less.

(C) The diester compound may be a mixture of polyalkylene glycol diesters having the same R ³ and different n. In the same molecule, n R ³ may be the same as or different from each other. When the (C) diester compound is a mixture, it is preferable that n of each component (total component or main component) is an integer in a range of 3 to 25, or an average value of n is in a range of 3 to 25. number. In the case where n is an average value, the value of n may be a non-integer. The average value of n may be a calculated value based on an average molecular weight such as a number average molecular weight or a weight average molecular weight. The weight average molecular weight of the (C) diester compound is preferably 300 to 1200.

The (C) diester compound of the present invention is an ester of a polyalkylene glycol and a saturated fatty acid, and is a saturated fatty acid having 5 to 18 carbon atoms (the carboxyl group removed) An alkyl group having 4 to 17 carbon atoms is preferably obtained by diesterification. Further, as specific examples of the (C) diester compound, for example, polyethylene glycol di-2-ethylpropionate, polyethylene glycol di-2-ethylbutyrate, and polyethylene glycol di 2-ethylhexanoate, polyethylene glycol dicaprylate, polyethylene glycol di-2-methylvalerate, polyethylene glycol di-2-methylbutyrate, polyethylene glycol Di-3-methylbutyrate, polyethylene glycol di-2-methylhexanoate, polyethylene glycol di-2-ethylvalerate, polyethylene glycol and 2-ethylpropionic acid. Esters of 2-ethylhexanoic acid, polyethylene glycol and 2-methylhexanoic acid. Esters of 2-ethylvaleric acid, polyethylene glycol and 3-methylhexanoic acid. Esters of 5-methylhexanoic acid, polyethylene glycol and 2-methylhexanoic acid. Esters of 2-ethylhexanoic acid, polyethylene glycol and 3,5-dimethylhexanoic acid. 4,5-dimethylhexanoic acid. Esters of 3,4-dimethylhexanoic acid, polyethylene glycol distearate, polypropylene glycol di-2-ethylpropionate, polypropylene glycol di-2-ethylbutyrate, polypropylene glycol di- 2-ethylhexanoate, polypropylene glycol dicaprylate, polypropylene glycol di-2-methylvalerate, polypropylene glycol di-2-methylbutyrate, polypropylene glycol di-3-methylbutyrate , Polypropylene glycol di-2-methylhexanoate, polypropylene glycol di-2-ethylvalerate, esters of polypropylene glycol and 2-ethylpropanoic acid, 2-ethylhexanoic acid, polypropylene glycol and 2-methyl Hexanoic acid‧Ester of 2-ethylvaleric acid, Polypropylene glycol and 3-methylhexanoic acid‧Ester of 5-methylhexanoic acid, Polypropylene glycol and 2-methylhexanoic acid‧Ester of 2-ethylhexanoic acid Esters of polypropylene glycol with 3,5-dimethylhexanoic acid, 4,5-dimethylhexanoic acid, 3,4-dimethylhexanoic acid, polypropylene glycol distearate, polyisopentanediol di 2-ethyl propionate, polyisopentyl glycol di-2-ethylbutyrate, polyisopentyl glycol di-2-ethylhexanoate, polyisopentyl glycol dicaprylate, poly Isoamyl glycol di-2-methylvalerate, polyisoamyl glycol di-2-methylbutyrate, polyisoamyl glycol di-3-methylbutyrate, polyisoamyl glycol di -2-A Caproic acid ester, polyisopentanediol di-2-ethylvalerate, esters of polyisopentanediol with 2-ethylpropanoic acid, 2-ethylhexanoic acid, polyisopentanediol and 2-methyl Hexanoic acid‧Ester of 2-ethylvaleric acid, polyisopentanediol and 3-methylhexanoic acid‧Ester of 5-methylhexanoic acid, polyisopentanediol and 2-methylhexanoic acid‧2- Ester of ethylhexanoic acid, polyisopentanediol and 3,5-dimethylhexanoic acid, 4,5-dimethylhexanoic acid, ester of 3,4-dimethylhexanoic acid, polyisopentanediol Distearate and the like.

In order to crosslink an acrylic polymer when forming an adhesive layer, the adhesive composition of this invention contains a crosslinking agent. Examples of the crosslinking agent include difunctional or higher isocyanate compounds. The content of the cross-linking agent is not particularly limited, and the (D) isocyanate compound is preferably contained in a proportion of 0.01 to 5 parts by weight, and more preferably contained in a proportion of 0.02 to 3 parts by weight, based on 100 parts by weight of the acrylic polymer.

(D) The isocyanate compound is preferably an isocyanurate body selected from a hexamethylene diisocyanate compound, an isocyanurate body of an isophorone diisocyanate compound, or a hexamethylene diisocyanate compound. Adduct, adduct of isophorone diisocyanate compound, biuret body of hexamethylene diisocyanate compound, biuret body of isophorone diisocyanate compound, isocyanuride of toluene diisocyanate compound Ester body, isocyanurate body of xylylene diisocyanate compound, isocyanurate body of hydrogenated xylyl diisocyanate compound, adduct of toluene diisocyanate compound, xylyl diisocyanate One or more trifunctional isocyanate compounds among compound adducts and hydrogenated xylyl diisocyanate compounds.

The adhesive composition of the present invention contains, as the (E) antioxidant, one or more compounds selected from the group consisting of a phenol-based antioxidant and a phosphite-based antioxidant. (E) The content of the antioxidant is not particularly limited, and it is preferably contained in an amount of 0.01 to 1.0 part by weight based on 100 parts by weight of the acrylic polymer, and more preferably in an amount of 0.02 to 1.0 part by weight. The content is particularly preferably contained in a proportion of 0.02 to 0.8 parts by weight, and most preferably contained in a proportion of 0.04 to 0.7 parts by weight. By adding the (E) antioxidant to the adhesive composition of the present invention, it is possible to suppress the adhesive layer from being oxidized to cause yellowing (increased b ^* value).

Examples of the phenol-based antioxidant include 2,6-di-tert-butyl-4-hydroxytoluene, tert-butyl p-hydroxyanisole, vitamin E (tocopherols), and 2,2-thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], tetra [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester, Stearyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -2 , 4,6-trimethylbenzene, N, N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxyamphetamine), 1,3,5-tris (3,5 -Di-tert-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6-trione, 1,3,5-trimethyl-2,4,6-tri (3 , 5-di-tert-butyl-4-hydroxybenzyl) isocyanurate and the like. Among the phenol-based antioxidants, a hindered phenol-based antioxidant having a bulky alkyl group such as a tert-butyl group at two ortho positions of the hydroxyl group is preferred.

Examples of the phosphite-based antioxidant include triphenyl phosphite, tricresyl phosphite, tri (nonylphenyl) phosphite, and tris (2,4-di-tert-butyl) phosphite. Phenyl) ester, phenyl diisodecyl phosphite, diphenyl isodecyl phosphite, trialkyl phosphite, distearyl pentaerythritol diphosphite, bis (2,4-ditert Butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4methylphenyl) pentaerythritol diphosphite, and the like.

The adhesive composition of the present invention may contain an antistatic agent in order to impart antistatic properties to peeling static electricity and the like. The content of the antistatic agent is not particularly limited. The antistatic agent is preferably contained in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the acrylic polymer. When it is not necessary to impart antistatic properties, the adhesive composition of the present invention may not contain an antistatic agent.

Examples of the antistatic agent include ionic compounds having a melting point of 25 ° C or higher and solids at a temperature of 25 ° C. The ionic compound has an inorganic or organic cation and an inorganic or organic anion. The cation of the ionic compound is preferably a cation selected from the group consisting of pyridinium, imidazolium, sulfonium, pyrrolidinium, guanidinium, ammonium, isourenium, thiourea, piperidinium, and pyrazolium. One of the group. These cations may have one or more substituents such as an alkyl group.

As the anion of the ionic compound, selected from the group consisting of include hexafluorophosphate (PF ₆ ^-), thiocyanate (SCN ^-), organic sulfonate (RSO ₃ ^-), perchlorate (ClO ₄ ^- ), tetrafluoroborate (BF ₄ ^-), bis (fluorosulfonyl acyl) imide salt ^{_{[(FSO 2) 2 N -}} ], bis (trifluoromethane sulfonic acyl) imide salt [(CF ₃ SO ₂ one kind] anions, such as the group consisting of ^-) ₂ N ^-], bis (pentafluoroethane sulfonic acyl) imide salt _{[(C 2 F 5 SO 2} ) 2 N.

When the adhesive composition contains an antistatic agent, the surface resistivity of the adhesive layer obtained by crosslinking the adhesive composition is preferably 1.0 × 10 ⁺¹¹ Ω / □ or less.

The adhesive composition of the present invention may be further appropriately blended with known additives such as a silane coupling agent, a surfactant, a curing accelerator, a plasticizer, a filler, a curing delaying agent, a processing aid, and an anti-aging agent. ingredient. These additives can be used individually or in combination of 2 or more types.

According to the adhesive composition of the present invention, not only excellent transparency can be obtained when the thickness of the adhesive layer is thickly applied, but also the anti-turbidity performance can be improved when it is placed in an atmosphere of high temperature and high humidity. In the adhesive layer having a coating thickness of 175 μm formed by crosslinking the adhesive composition, the haze value of the adhesive layer is preferably 1.0% or less. In addition, after the adhesive layer having a coating thickness of 175 μm was left in an atmosphere at a temperature of 85 ° C. and 85% RH for 240 hours, the haze value of the adhesive layer when taken out to a room temperature environment was greater than 0.0% and was 4.0% or less, and preferably a b ^* value of more than 0.0 and 0.5 or less. Here, the b ^* value is L ^* a ^* b ^* b ^* value in the chromaticity system. If the b ^* value is a large positive value, yellow becomes stronger, and if the b ^* value is a large negative value, blue is used. Become stronger. The b ^* value is preferably greater than 0.0. In addition, according to an adhesive composition having excellent transparency even when the thickness of the adhesive layer is thickly applied, when the thickness of the adhesive layer is thin, it has more excellent transparency than when it is thickly applied.

In the adhesive film of the present invention, an adhesive formed from the adhesive composition of the present invention can be laminated on one surface of a resin film. The adhesive film of the present invention can be used for various applications such as touch panels, electronic papers, organic electroluminescence, optical members, and surface protection. The thickness of the adhesive layer is not particularly limited, and is, for example, 5 to 2000 μm. If the thickness of the adhesive layer is too thin, the impact absorption performance is deteriorated, and if the thickness of the adhesive layer is too thick, it is disadvantageous in terms of cost increase. In particular, in the case of an adhesive film for a touch panel, when the thickness of the adhesive layer is 175 μm or more, the effect of the present invention is high, so it is preferable. The thickness of the adhesive layer used for bonding between members (for example, bonding of a polarizing plate and a panel) is preferably 5 to 25 μm. The thickness of the adhesive layer used in the optical film for a touch panel is preferably 25 to 250 μm.

As a resin film which becomes a base material of an adhesive layer, and the peeling film (separation film) which protects the surface of an adhesive layer, resin films, such as a polyester film, etc. can be used. When the application of the adhesive film is an optical surface protective film such as a surface protective film for polarizing plates, it is preferable that the resin film and the adhesive layer have sufficient transparency. In addition, the adhesive film can also be used for bonding a polarizer and an In-cell panel. In addition, the adhesive film can also be used for bonding a polarizing plate having a COP (cycloolefin polymer) film on one side of the protective film to a panel.

In addition, the adhesive composition of the present invention can be used for a laminated film in which various films are laminated through the adhesive layer. Examples of such a film include a film for a touch panel, a film for electronic paper, a film for organic electroluminescence, and a film for optics.

In addition, the adhesive composition of the present invention can also be used for an optical film with an adhesive on which at least one side of the optical film is laminated.

In the optical film with an adhesive, as the base film, optical films such as a polarizer film, a retardation film, a lens film, a polarizer film used as a retardation film, and a polarizer film used as a lens film can be used.

The optical film with an adhesive is an optical film with an adhesive formed by laminating an adhesive on one or both sides of an optical film, and can be used for bonding to a glass plate or the like of an image display device. These adhesive-attached optical films are bonded to a glass substrate or the like via an adhesive layer, and can be assembled into an image display device or the like. The adhesive layer used in an adhesive-attached optical film such as an adhesive-attached polarizing plate is preferred to have sufficient transparency.

[Example]

Hereinafter, the present invention will be specifically described using examples.

<Preparation of acrylic polymer>

[Example 1]

Nitrogen was introduced into a reaction device including a stirrer, a thermometer, a reflux cooler, and a nitrogen introduction tube, and the air in the reaction device was replaced with nitrogen. Then, 90 parts by weight of butyl acrylate, 10 parts by weight of methyl methacrylate, 8.0 parts by weight of 8-hydroxyoctyl acrylate, and 100 parts by weight of a solvent (ethyl acetate) were added to the reaction apparatus. Then, 0.1 part by weight of azobisisobutyronitrile as a polymerization initiator was added dropwise over 2 hours, and the mixture was reacted at 65 ° C for 8 hours to obtain an acrylic polymer solution of Example 1 having a weight average molecular weight of 800,000.

[Examples 2 to 5 and Comparative Examples 1 to 4]

Example 2 was obtained in the same manner as in the acrylic polymer solution used in Example 1 except that the composition of the monomers were as described in Tables (A), (B), and (F), respectively. ~ 5 and the acrylic polymer solutions of Comparative Examples 1-4. Here, (F) represents a copolymerizable monomer containing a carboxyl group. The weight average molecular weight of the acrylic polymer is in the range of 200,000 to 2 million.

<Manufacture of an adhesive composition and an adhesive film>

[Example 1]

With respect to the acrylic polymer solution of Example 1, polypropylene glycol distearate (molecular weight 800) was added in a proportion of 5 parts by weight, Coronate (registered trademark) L was added in a proportion of 0.3 parts by weight, and 0.1 part by weight of IRGANOX (registered trademark) 1010 was added at a ratio, and the mixture was stirred and mixed to obtain the adhesive composition of Example 1.

This adhesive composition was coated on a release film formed of a polyethylene terephthalate (PET) film coated with a silicone resin, and then dried at 90 ° C to remove the solvent to obtain an adhesive. The thickness of the layer was 175 μm.

Then, the adhesive sheet was transferred onto a polyethylene terephthalate (PET) film to obtain a laminated structure having "PET film / adhesive layer / release film (PET film coated with silicone resin)". The adhesive film of Example 1.

[Examples 2 to 5 and Comparative Examples 1 to 4]

An example was obtained in the same manner as in the adhesive composition and the adhesive film of Example 1 described above except that the additives were as described in Tables (C), (D), (E), and (X). Adhesive compositions and adhesive films of 2 to 5 and Comparative Examples 1 to 4. Here, (X) represents an ionic compound.

In Table 1, the blending ratio of each component is shown as a numerical value of parts by weight obtained by setting the total of (A) and (B) to 100 parts by weight in parentheses.

Moreover, the compound name of the abbreviated symbol of each component used in Table 1 is shown in Table 2. In addition, in group (D) of Table 2, HDI means hexamethylene diisocyanate, and TDI means toluene diisocyanate.

Coronate (registered trademark) L, Coronate HX, and Coronate HL are trade names of TOSOH Corporation. TAKENATE (registered trademark) D-110N is a trade name of Mitsui Chemicals Corporation. IRGANOX (registered trademark) 1010 and IRGAFOS (registered trademark) 168 are trade names of BASF Corporation.

<Test method and evaluation>

The adhesive films of Examples 1 to 5 and Comparative Examples 1 to 4 were cured in an atmosphere of 23 ° C and 50% RH for 7 days, and then the release film (a silicone resin-coated PET film) was peeled off to expose the adhesive. The adhesive film of the layer was used as a measurement sample of total light transmittance and surface resistivity.

In addition, the adhesive films of Examples 1 to 5 and Comparative Examples 1 to 4 were cured in an atmosphere of 23 ° C and 50% RH for 7 days, and then the adhesive was covered with a release film (a PET film coated with a silicone resin). Samples in the state of both sides of the layer were used as measurement samples for the haze value and b * value.

In addition, one side of the adhesive layer of an adhesive film manufactured in the same manner was set to a thickness of 25 μm of the adhesive layer, and one surface of the protective layer was affixed to a polarizing plate of a COP film by transfer. Then, the surface on the opposite side of the adhesive layer was bonded to the surface of an alkali-free glass plate (0.7 mm in thickness), left for 1 day, and then subjected to autoclave treatment at 50 ° C and 5 atmospheres for 20 minutes. A sample that was left for 12 hours at a temperature was used as a sample for measuring adhesion and durability.

<Method for measuring total light transmittance>

About the measurement sample of the total light transmittance obtained above, the total light transmittance of the adhesive layer was measured using a haze meter (manufacturer: Nippon Denshoku Corporation, model: Haze Meter, NDH 2000) in accordance with JIS K7105.

<Method for measuring haze value and b ^* value before and after wet heat treatment>

Respect to the haze value measured samples and b ^* values, using a haze meter (manufacturer: Nippon Denshoku Co. Ltd., Model: Haze Meter, NDH2000), the haze value of the adhesive layer, and b ^* value Was measured. This was used as a haze value and a b ^* value before the wet heat treatment.

Further, the measured samples of the haze value and b ^* value were left in an atmosphere at a temperature of 85 ° C and 85% RH for 240 hours, and then taken out to a room temperature environment, and the haze value and b ^* value of the adhesive layer were measured. . This was used as the haze value and b ^* value after the wet heat treatment.

In addition, among the above measurement samples, a sample in which both surfaces of the adhesive layer were covered with a release film (a PET film coated with a silicone resin) was used as a measurement sample of the haze value and b *, but the mist of the release film itself was Both the degree value and the b ^* value have been confirmed to be small enough to be ignored.

<Method for measuring adhesive force>

Using a tensile tester, the sample for measuring the adhesive force (a sample obtained by bonding a 25 mm wide adhesive film to the surface of an alkali-free glass plate) was peeled in a direction of 180 ° at a tensile speed of 0.3 m / min. Hereinafter, the measured peeling strength is referred to as an adhesive force (N / 25 mm).

<Evaluation method of durability>

The durability measurement sample obtained as described above was left in an atmosphere of 80 ° C (dry) for 250 hours, and then taken out to room temperature, and it was visually confirmed whether it peeled from the adherend, bubbling, or the like. The evaluation criteria were: "○" when no peeling or foaming was recognized at all, "△" when a few peeling or foaming was confirmed, and "" × ".

<Method for measuring surface resistivity>

About the surface resistivity measurement sample obtained above, the surface resistivity (Ω / □) of the adhesive layer was measured using a resistivity meter HRESTA UP-HT450 (manufactured by Mitsubishi Chemical Analytech Co., Ltd.).

The measurement results and evaluation results are shown in Table 3. In addition, the surface resistivity is expressed by a method in which “m × 10 ^{+ n} ” is “mE + n” (where m is an arbitrary real value and n is a positive integer).

table 3     

The adhesive films of Examples 1 to 5 not only have the transparency when the adhesive layer is thickly coated (175 μm) (the total light transmittance is more than 90%, the haze value is less than 1.0%), but also have white turbidity after wet heat treatment. Also small white turbidity resistance (haze value after wet heat treatment is greater than 0.0% and 4.0% or less, and b ^* value is more than 0.0 and 0.5 or less), which can improve white turbidity resistance. Furthermore, even if it is left in a high-temperature atmosphere for a long time, it does not cause peeling and foaming, and has durability.

In the adhesive film of Comparative Example 1, the haze value and b ^* value after the wet heat treatment were increased, and there was a problem in the anti-clouding performance. This is considered to be because the (C) diester compound and (E) antioxidant were not contained in the adhesive composition of Comparative Example 1.

In addition, for the adhesive film of Comparative Example 2, the b ^* value after the wet heat treatment was increased, and there was a problem with the anti-cloudiness performance. Moreover, when it was left in a high-temperature atmosphere for a long time, it was found to have peeling and foaming, and there was a problem with durability. This is considered to be because, in the adhesive composition of Comparative Example 2, the acrylic polymer was copolymerized with (B) a hydroxyl group-containing copolymerizable monomer, thereby suppressing the haze value after the wet heat treatment. It increases, but causes a reduction in durability, and also does not contain (E) an antioxidant, causing an increase in b ^* value.

The adhesive film of Comparative Example 3 had a large haze value before the wet heat treatment and a large haze value after the wet heat treatment. This is considered to be because the n value of the (C) diester compound in the adhesive composition of Comparative Example 3 was too large, and (E) an antioxidant was excessively added.

In addition, for the adhesive film of Comparative Example 4, the compound with an excessively large n value of the (C) diester compound may have an anti-white turbidity property that is less white turbid after the wet heat treatment (the haze value after the wet heat treatment is greater than 0.0% to 4.0% or less, and b ^* value is greater than 0.0 to 0.5 or less), but causes a decrease in durability and a decrease in the adhesive force of the adhesive layer.

Claims (12)

An adhesive composition comprising an acrylic polymer and a cross-linking agent, wherein the acrylic polymer has a number of carbon atoms with respect to 100 parts by weight of the (A) alkyl group in total. At least one or more of the (meth) acrylic acid ester monomers of C1 to 18, and at least one or more of the (B) copolymerizable monomers containing a hydroxyl group as a copolymerizable monomer group in a ratio of 0.1 to 10 parts by weight An acrylic polymer formed by copolymerization of a copolymer having a weight average molecular weight of 200,000 to 2 million and an acid value of 5.0 or less, and the adhesive composition further contains (C) represented by the following formula (1): ) At least one or more diester compounds, (D) an isocyanate compound as the crosslinking agent, and (E) an antioxidant selected from an antioxidant group consisting of a phenol-based antioxidant and a phosphite-based antioxidant One or more compounds containing the (E) antioxidant, R ¹ COO- (R ³ -O) _n -CO-R with respect to 100 parts by weight of the acrylic polymer in a ratio of 0.01 to 1.0 parts by weight. ² (1) wherein R ¹ and R ² each represent an alkyl group having 4 to 17 carbon atoms; R ³ represents Shows an alkylene group having 2 to 5 carbon atoms; n represents an integer of 3 to 25.     The adhesive composition according to item 1 of the scope of the patent application, wherein the weight average molecular weight of the (C) diester compound is 300 to 1200, and 0.1 to 100 parts by weight of the acrylic polymer. The (C) diester compound is contained in a proportion of 20 parts by weight.     The adhesive composition according to item 1 or 2 of the scope of application for a patent, wherein, in an adhesive layer having a coating thickness of 175 μm formed by crosslinking the adhesive composition, the haze value of the adhesive layer When the adhesive layer is 1.0% or less, the adhesive layer has a haze value of more than 0.0% and 4.0% after being left for 240 hours under an atmosphere of a temperature of 85 ° C and 85% RH. Below, and the b ^* value is greater than 0.0 and 0.5 or less.     The adhesive composition according to item 1 or 2 of the scope of patent application, wherein (B) the copolymerizable monomer containing a hydroxyl group is selected from the group consisting of (meth) acrylic acid 8-hydroxyoctyl ester, (meth) 6-hydroxyhexyl acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (methyl At least one or more of the compound group consisting of acrylamide and N-hydroxyethyl (meth) acrylamide.         The adhesive composition according to item 1 or 2 of the scope of patent application, wherein the copolymerizable monomer group contains a carboxyl group-containing copolymerizable monomer selected from (meth) acrylic acid and carboxyethyl (methyl) Acrylate), carboxypentyl (meth) acrylate, 2- (meth) acryloxyethylhexahydrophthalate, 2- (meth) acryloxypropylhexahydrophthalate Dicarboxylic acid, 2- (meth) acryloxyethyl phthalic acid, 2- (meth) acryloxyethyl succinic acid, 2- (meth) acryloxyethyl maleic acid At least one or more of the compound group consisting of carboxy polycaprolactone mono (meth) acrylate and 2- (meth) acryloxyethyltetrahydrophthalic acid.     The adhesive composition according to item 1 or 2 of the scope of application for a patent, wherein the adhesive composition further contains, as an antistatic agent, an ionic compound having a melting point of 25 ° C or higher and a solid at a temperature of 25 ° C. The ionic compound is a cationic component selected from a cationic group consisting of pyridinium, imidazolium, osmium, hydrazone, pyrrolidinium, guanidinium, ammonium, isourenium, thiourenium, piperidinium, and pyrazolium. The ionic compound contains the antistatic agent in an amount of 0.01 to 5 parts by weight relative to 100 parts by weight of the acrylic polymer, and the surface resistivity of the adhesive layer obtained by crosslinking the adhesive composition is 1.0 × 10 ⁺¹¹ Ω / □ or less.     The adhesive composition according to item 1 or 2 of the scope of patent application, wherein the (D) isocyanate compound is an isocyanurate body or isophorone diisocyanate selected from a hexamethylene diisocyanate compound. Isocyanurate body of compound, adduct of hexamethylene diisocyanate compound, adduct of isophorone diisocyanate compound, biuret body of hexamethylene diisocyanate compound, isophorone Biuret bodies of diisocyanate compounds, isocyanurate bodies of toluene diisocyanate compounds, isocyanurate bodies of xylyl diisocyanate compounds, isocyanurate bodies of hydrogenated xylyl diisocyanate compounds, One or more trifunctional isocyanate compounds among an adduct of a toluene diisocyanate compound, an adduct of a xylyl diisocyanate compound, and an adduct of a hydrogenated xylyl diisocyanate compound with respect to 100 parts by weight of the acrylic acid Based polymer containing the (D) isocyanate compound in a proportion of 0.01 to 5 parts by weight.         An adhesive film is characterized in that an adhesive obtained by cross-linking the adhesive composition according to any one of claims 1 to 7 of the patent application scope is laminated on one surface of a resin film.         A pressure-sensitive adhesive film, wherein the thickness of the pressure-sensitive adhesive layer used for bonding a polarizer and an In-cell panel used in the pressure-sensitive adhesive film described in item 8 of the patent application range is 5 to 25 μm.         An adhesive film, wherein the thickness of the adhesive layer of the polarizer and the panel of one side of the protective film used for the adhesive film used in the adhesive film described in item 8 of the patent application range is 5 ~ 25 μm.         An optical film for a touch panel, wherein the thickness of the adhesive layer used in the adhesive film described in item 8 of the patent application range is 25-250 μm.         An optical film with an adhesive, wherein an adhesive obtained by cross-linking the adhesive composition according to any one of claims 1 to 7 of the patent application scope is laminated on at least one side of the optical film .