KR20180018299A - Adhesive composition for optical film, adhesive layer and method for producing the same, optical member and image display device - Google Patents

Abstract

The present invention relates to an adhesive composition for optical films, comprising: (A) a (meth) acrylate copolymer including (a1) 80-99.9% by weight of a structural unit derived from an alkyl (meth) acrylate monomer, (a2) 0.01-5% by weight of a structural unit derived from a (meth) acrylate monomer having a hydroxyl group, and (a3) 15% by weight or less of a structural unit derived from a monomer other than the monomers forming structural units (a1) and (a2); (B) a peroxide; and (C) a crosslinking agent other than the peroxide (B). The adhesive composition for optical films can obtain excellent durability and reworkability even in a severe environment (high temperature, high humidity, heat shock, etc.).

Description

Technical Field [0001] The present invention relates to a pressure-sensitive adhesive composition for an optical film, a pressure-sensitive adhesive layer, a production method thereof, an optical member and an image display device.

The present invention relates to a pressure-sensitive adhesive composition for an optical film, a pressure-sensitive adhesive layer formed therefrom, a process for producing the pressure-sensitive adhesive layer, an optical member using the pressure-sensitive adhesive layer, and an image display device using the optical member.

Optical members such as various optical films for improving the display quality of the display can be adhered to a liquid crystal panel such as a liquid crystal display device, which is a kind of image display apparatus, in addition to a polarizing film (polarizing plate), which is an essential element. When an optical member such as an optical film is adhered to a liquid crystal panel or two or more identical or different optical films are adhered to each other, a pressure sensitive adhesive is usually used.

Such a pressure-sensitive adhesive is required to have durability in an adhesive state to such an extent that defects such as peeling or peeling due to a pressure-sensitive adhesive do not occur during an endurance test (environmental promotion test) by heating, humidification or the like. In particular, the durability of an optical film used in a vehicle-use panel is required to be such that no defects such as peeling or peeling caused by a pressure-sensitive adhesive occur even in a durability test under a high temperature and high humidity environment.

Further, when the optical film is bonded to the liquid crystal panel by using the pressure-sensitive adhesive, the optical film must be peeled off from the liquid crystal panel and re-bonded when foreign matter is stuck on the bonding surface. In recent years, the use of a liquid crystal display device such as a thin liquid crystal panel using a chemically etched glass has been increased in addition to a conventional liquid crystal display device manufacturing process, and the optical film tends to be thinner and tapered, When a conventional pressure sensitive adhesive is used for a display device or a thin optical film, there arises a problem that the thin liquid crystal display device or the thin optical film is broken or broken due to insufficient durability. Therefore, in the related peeling process, a property of a pressure-sensitive adhesive called re-peeling property (also referred to as re-workability) that can easily peel an optical film from a liquid crystal display device or the like without residue of a paste has been demanded.

Further, in order to improve the productivity, it is more preferable to have good handleability in terms of the production process.

As such a pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive has been widely used. Generally, bonding using an acrylic pressure-sensitive adhesive containing a solvent is carried out as follows. First, a pressure-sensitive adhesive composition comprising a (meth) acrylate-based resin and a crosslinking agent is prepared and applied to the release surface side of the process film. Then, a crosslinked structure is formed between the (meth) acrylate-based resins by drying and curing the layer comprising the applied pressure-sensitive adhesive composition, and the pressure-sensitive adhesive layer formed on the side of the process film is transferred to one side of the optical film , An optical member (adhesive optical film) including a process film is obtained. Thereafter, the process film is bonded to another optical film or the liquid crystal panel as the other film, whereby the two adherends are closely adhered to the pressure-sensitive adhesive layer. As described above, when a pressure-sensitive adhesive layer having a crosslinking treatment is formed on one side of an optical film, there is an advantage that a drying process for adhesion after bonding is not performed.

Examples of the method for producing the pressure-sensitive adhesive composition or the pressure-sensitive adhesive layer for an optical film as described above include those disclosed in JP-A-2006-183022 A, JP-A No. 1212-037895 A and JP- (B) and 0.02 to 2 parts by weight of an isocyanate compound (C) relative to 100 parts by weight of an acryl-based polymer (A) containing an alkyl (meth) acrylate as a copolymerizable component To 2 parts by weight of a pressure-sensitive adhesive for an optical film. According to the document, the structure of the related pressure-sensitive adhesive composition makes it possible to suppress warpage and light leakage due to stress due to dimensional changes of members such as optical films, improve durability, The good adhesion type optical film can be obtained.

Patent Document 4 (JP2006-348307 A) discloses a composition comprising 100 parts by weight of an acrylic polymer having a gel fraction of 30 to 90% by weight and an acrylic ester having an alkyl group having 4 or more carbon atoms as a monomer unit, 0.02 to 2 parts by weight of peroxide, Discloses a pressure-sensitive adhesive layer formed by treating a pressure-sensitive adhesive composition comprising 0.01 to 1 part by weight of a peroxide crosslinking agent.

Patent Document 5 (JP2006-143858 A) discloses a composition comprising 100 parts by weight of a (meth) acryl-based polymer containing an alkyl (meth) acrylate having an alkyl group having 4 or more carbon atoms as a monomer unit and an unsaturated carboxylic acid, an aliphatic and / or alicyclic isocyanate- 0.01 to 5 parts by weight of a crosslinking agent, 0.02 to 2 parts by weight of a peroxide, and 0.01 to 1 part by weight of a silane coupling agent.

Patent Document 6 (JP2007-112901 A) discloses a pressure-sensitive adhesive sheet having a thickness of 20 占 퐉 or more formed by a pressure-sensitive adhesive composition comprising 100 parts by weight of an acrylic polymer containing acrylic ester having an alkyl group having 4 or more carbon atoms as a monomer unit and 0.02 to 2 parts by weight of peroxide .

According to the above-mentioned Patent Documents 4 to 6, even when the screen display device is reused (bonding and peeling of the optical member), the adhesion of the related art pressure sensitive adhesive composition increases, (Durability is excellent), and the punching processing can be performed quickly after the optical member is manufactured, which is advantageous in that the productivity is excellent.

Patent Document 7 (JP2009-242786 A) discloses a composition comprising 100 parts by weight of a (meth) acryl-based polymer containing an alkyl (meth) acrylate having an alkyl group having 4 to 14 carbon atoms as a monomer unit and a carboxyl group- 0.02 to 2 parts by weight of peroxide and 0.005 to 5 parts by weight of an epoxy cross-linking agent. According to the document, the pressure-sensitive adhesive composition can form a pressure-sensitive adhesive layer capable of suppressing yellowing, foaming, peeling, and the like even under a high-temperature and high-humidity environment.

Patent Documents 8 to 11 disclose a method for producing a pressure-sensitive adhesive layer.

Specifically, in Patent Document 8 (JP2007-107016 A), per 100 parts by weight of the (meth) acrylic polymer (A) in which the alkyl (meth) acrylate contains a hydroxyl group-containing (meth) acrylic monomer as a copolymerization component, peroxide ), And 0.001 to 2 parts by weight of an isocyanate compound (C) is subjected to a crosslinking reaction to form a pressure-sensitive adhesive layer. Patent Document 9 (JP2012-031419 A) discloses a method for producing a pressure- Discloses a method for producing a pressure-sensitive adhesive layer in which a pressure-sensitive adhesive composition having the same composition as in Patent Document 8 is applied to a release sheet in the form of a release sheet and subjected to heat treatment and crosslinking reaction to form a pressure-sensitive adhesive layer. These patent documents disclose a pressure-sensitive adhesive optical film which is capable of suppressing warping and light leakage due to stress due to dimensional changes of members such as optical films, high durability, good handleability in terms of manufacturing process, and good quality Can be obtained.

Patent Document 10 (JP2015-025125 A) and 11 (JP2015-165030 A) disclose a method of forming a pressure-sensitive adhesive composition layer containing a (meth) acrylic polymer, a peroxide and a phenol-based antioxidant on a release- And a second step of heating the pressure-sensitive adhesive composition after the first step and crosslinking the pressure-sensitive adhesive composition to form a pressure-sensitive adhesive layer. According to these patent documents, it is possible to manufacture a pressure-sensitive adhesive layer with a separator having a moderate light fastness to the pressure-sensitive adhesive layer and excellent in workability and durability.

However, the conventional pressure-sensitive adhesive composition may have insufficient reworkability and / or light leakage suppressing effect. Particularly, there is a fear that it is not sufficient to make both durability and reworkability compatible in a harsh environment (high temperature, high humidity, heat shock, etc.).

Therefore, development of a pressure-sensitive adhesive composition capable of achieving excellent durability and reworkability even in a severe environment is required.

An object of the present invention is to provide a pressure-sensitive adhesive composition for an optical film which can obtain excellent durability and reworkability even under severe environments (high temperature, high humidity, heat shock, etc.).

Another object of the present invention is to provide a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition for an optical film, an optical member using the pressure-sensitive adhesive layer, and an image display apparatus using the optical member.

Another object of the present invention is to provide a method for producing the adhesive layer.

The above and other objects of the present invention can be achieved by the present invention described below.

One aspect of the present invention relates to a pressure-sensitive adhesive composition for an optical film. The pressure-sensitive adhesive composition for an optical film according to any one of (1) to (8), wherein the pressure-sensitive adhesive composition for optical films comprises (A) 80 to 99.9% by weight of a structural unit derived from an alkyl (meth) acrylate monomer, (a2) 0.01 to 5% by weight of a structural unit derived from a hydroxyl group- And (a3) a (meth) acrylate copolymer containing 15% by weight or less of constituent units derived from a monomer other than the monomer constituting the constituent units (a1) and (a2); (B) a peroxide; And (C) a crosslinking agent other than the peroxide (B).

Another aspect of the present invention relates to a pressure-sensitive adhesive layer for an optical film. And the pressure-sensitive adhesive layer for an optical film is formed from the pressure-sensitive adhesive composition for an optical film.

Another aspect of the present invention relates to an optical member. Wherein the optical member comprises a pressure-sensitive adhesive layer for the optical film; And a first optical film provided on one side of the pressure-sensitive adhesive layer for the optical film.

Another aspect of the present invention relates to an image display apparatus. The image display device may include at least one optical member.

Another aspect of the present invention relates to a method for producing a pressure-sensitive adhesive layer for an optical film. The above manufacturing method comprises: applying the pressure-sensitive adhesive composition for an optical film on a release sheet obtained by peeling; And subjecting the applied pressure-sensitive adhesive composition for an optical film to a cross-linking reaction by heat treatment.

The present invention relates to a pressure-sensitive adhesive composition for an optical film which can obtain excellent durability and reworkability under severe environments (high temperature, high humidity, heat shock, etc.), a pressure-sensitive adhesive layer formed therefrom, An optical member using the pressure-sensitive adhesive layer, and an image display apparatus using the optical member.

Hereinafter, the present invention will be described in detail.

Pressure sensitive adhesive composition for optical film

The pressure-sensitive adhesive composition for an optical film according to the present invention comprises (A) a (meth) acrylate copolymer; (B) a peroxide; And (C) a crosslinking agent.

(A) a (meth) acrylate copolymer

The (meth) acrylate copolymer according to one embodiment of the present invention reacts with the peroxide (B) and / or the cross-linking agent (C) to form a cross-linking structure, thereby exhibiting adhesiveness (stickiness). As used herein, "(meth) acrylate" means either acrylate or methacrylate, or both acrylate and methacrylate.

(A1) a constituent unit derived from an alkyl (meth) acrylate monomer, (a2) a constituent unit derived from a (meth) acrylate monomer containing a hydroxy group (A3) 15% by weight or less of a constituent unit derived from a monomer other than the monomer constituting the constituent units (a1) and (a2). In the present specification, "Copolymer X contains y% by weight of a constituent unit derived from monomer Y" means that the copolymer X contains the monomer Y in an amount of 100% by weight based on the total amount of the monomer used for the synthesis of the copolymer X Means a copolymer obtained by copolymerizing a monomer mixture containing the copolymer in an amount of 0.1 to 10% by weight. Accordingly, the (meth) acrylate copolymer (A) preferably contains 80 to 99.9% by weight of the constituent unit (a1), 0.01 to 5% by weight of the constituent unit (a2), and 15% And the like.

In a specific example, the constitutional unit derived from the alkyl (meth) acrylate monomer (hereinafter referred to as the constitutional unit (a1)) of the above (a1) can contribute to basic properties as a pressure-sensitive adhesive, such as tackiness, in the pressure-sensitive adhesive composition for an optical film. The alkyl (meth) acrylate monomer may have any structure as far as the alkyl moiety is introduced into the ester moiety of the (meth) acrylate. The number of carbon atoms of the alkyl group is not particularly limited, but may be 1 to 20, for example, 1 to 12, specifically 1 to 10, specifically 1 to 8, specifically 1 to 6 from the viewpoints of versatility, cost and handling. The alkyl group may be in the form of a straight chain, a branched chain or a ring, but may be a straight chain or branched chain from the viewpoint of lowering the glass transition temperature. When the alkyl group is cyclic, the number of carbon atoms is 3 or more. Examples of the alkyl group include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, A cyclohexyl group, a cyclohexyl group, a 1-methylcyclohexyl group, an n-heptyl group, a 2-heptyl group, a 3-heptyl group, an isoheptyl group, a tert-heptyl group, A hexyl group, a heptyl group, a heptyl group, a heptyl group, a 2-ethylhexyl group, a nonyl group, an isononyl group, a decyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, . Particularly, a methyl group, an n-butyl group, an n-hexyl group, a 2-ethylhexyl group, a nonyl group and an isononyl group are preferable from the viewpoint of ensuring adhesion and securing basic characteristics.

Examples of the alkyl (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (Meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-pentyl Acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate and lauryl . From the viewpoints of heat durability and adhesion, methyl (meth) acrylate and n-butyl (meth) acrylate are preferable. These may include only one kind or two or more kinds of them in combination.

In the specific example, the content of the constituent unit (a1) in the (meth) acrylate copolymer (A) is 80 (meth) acrylate based on 100% by weight of the total amount of the constituent units constituting the To 99.9% by weight, for example from 80 to 99.5% by weight, specifically from 82 to 99.3% by weight, in particular from 85 to 99% by weight. When the content of the constituent unit (a1) is less than 80% by weight, the proportion of the polar monomer in the (meth) acrylate copolymer (A) relatively increases and the polarity of the formed pressure sensitive adhesive layer increases, When the proportion exceeds 99.9% by weight, the proportion of the polar monomer in the (meth) acrylate copolymer (A) is relatively decreased, making it difficult to ensure adhesion to the liquid crystal panel, and the durability may be lowered .

In a specific example, the structural unit derived from the hydroxyl group-containing (meth) acrylate monomer (hereinafter referred to as the structural unit (a2)) may be a crosslinking point in the (meth) acrylate copolymer (A) And the reactivity with the intermolecular crosslinking agent is abundant, so that it is possible to contribute to the improvement of cohesiveness and heat resistance of the pressure-sensitive adhesive layer. The hydroxy group-containing (meth) acrylate monomer may have any structure as far as the hydroxy group is introduced into a part of the (meth) acrylate.

Examples of the hydroxy group-containing (meth) acrylate monomer include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 1,6-hexanediol mono (Meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolethane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta Hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2- , Hydroxyethyl (meth) acrylamide, hydroxyethyl (meth) acrylamide, cyclohexanedimethanol monoacrylate, and the like, and alkyl glycidyl ether, aryl glycidyl ether, glycidyl ( Glycidyl group-containing compounds such as L) acrylate; And a compound obtained by an addition reaction with (meth) acrylic acid. (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate and the like are preferable from the viewpoints of good reactivity when an isocyanate crosslinking agent is used, (Meth) acrylamide and cyclohexanedimethanol monoacrylate are preferable, and 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are more preferable. These may include only one kind or two or more kinds of them in combination.

In the specific examples, the content of the constituent unit (a2) in the (meth) acrylate copolymer (A) is preferably 0.01 (meth) acrylate based on 100% by weight of the total amount of the constituent units constituting the To 5% by weight, such as 0.1 to 5% by weight, specifically 0.3 to 4% by weight, particularly 0.5 to 3% by weight. When the content of the constituent unit (a2) is less than 0.01% by weight, the crosslinking reaction point of the (meth) acrylate copolymer (A) becomes too small, and the durability of the pressure-sensitive adhesive layer may deteriorate. , The proportion of the polar monomer in the (meth) acrylate copolymer (A) relatively increases, so that the polarity of the pressure-sensitive adhesive layer to be formed is increased and the durability is lowered.

Specific examples of the monomer (a3) used in the constituent unit (hereinafter referred to as the constituent unit (a3)) derived from a monomer other than the monomer constituting the constituent unit (a1) and the monomer (a2) May include monomers contained in known (meth) acrylate copolymers within the range not to deteriorate the effect of the present invention. For example, the other monomers include unsaturated carboxylic acids; Aromatic ring containing (meth) acrylate monomers; Acrylic monomers having an epoxy group such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate; Acrylates having amino groups such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, N-tert-butylaminoethyl (meth) acrylate and methacryloxyethyltrimethylammonium chloride Monomers; Acryl monomer having an amide group such as (meth) acrylamide, N-methoxymethyl (meth) acrylamide and N, N-methylene bis (meth) acrylamide; Acrylic monomers having a phosphoric acid group such as trimethacryloyloxyethyl phosphate (meth) acrylate and triacryloyloxyethyl phosphate (meth) acrylate; Acryl monomers having sulfonic acid groups such as sodium sulfopropyl (meth) acrylate, sodium 2-sulfoethyl (meth) acrylate and sodium 2-acrylamide-2-methylpropane sulfonate; Acryl monomer having a urethane group such as urethane (meth) acrylate; Vinyltriethoxysilane, vinyltris (? -Methoxyethyl) silane, vinyltriacetylsilane, methacryloyloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltriethoxysilane, vinyltriethoxysilane, A vinyl monomer having a silane group; Styrene, chlorostyrene,? -Methylstyrene, vinyltoluene, vinyl chloride, vinyl acetate, vinyl propionate, acrylonitrile, vinyl pyridine and the like. These may include only one species, or two or more species may be combined.

Examples of the unsaturated carboxylic acid include unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid, anhydrous fumaric acid, crotonic acid, itaconic acid, itaconic anhydride, misteroolic acid, palmitoleic acid and oleic acid Can be exemplified. Among them, (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid, anhydrous fumaric acid, crotonic acid, itaconic acid and itaconic anhydride are preferable from the viewpoint of excellent polymerizability with other (meth) acrylic monomers , And (meth) acrylic acid are more preferable. These may include only one kind or two or more kinds of them in combination.

In an embodiment, as the other monomer, an aromatic ring-containing (meth) acrylate monomer is preferable in that an excellent light leakage suppressing effect can be obtained. Examples of the aromatic ring-containing (meth) acrylate monomers include benzyl (meth) acrylate, phenyl (meth) acrylate, o-phenylphenol (meth) acrylate phenoxy (meth) acrylate, phenoxyethyl (Meth) acrylate, phenoxyethyleneglycol (meth) acrylate, ethylene oxide modified nonylphenol (meth) acrylate, ethylene oxide modified cresol (meth) acrylate, phenol ethylene oxide modified (Meth) acrylate, methoxybenzyl (meth) acrylate, chlorobenzyl (meth) acrylate, cresyl (meth) acrylate, polystylyl Benzene ring-containing monomers such as a carboxylate; (Meth) acrylates such as hydroxyethylated? -Naphthol acrylate, 2-naphthoethyl (meth) acrylate, 2-naphthoxyethyl acrylate and 2- (4-methoxy-1-naphthoxy) Naphthalene ring-containing monomers; Biphenyl-containing monomers such as biphenyl (meth) acrylate; And the like. For example, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate and the like can be used from the viewpoint of light leakage suppression and excellent durability. These may include only one kind or two or more kinds of them in combination.

In a specific example, the content of the constituent unit (a3) in the (meth) acrylate copolymer (A) is preferably 15 (meth) acrylate copolymer For example, 0 to 10% by weight, specifically 0.1 to 5% by weight, specifically 0.5 to 3% by weight. If the content of the structural unit (a3) exceeds 15% by weight, durability may deteriorate as the polarity of the pressure-sensitive adhesive layer increases, or durability may deteriorate due to a decrease in polymerization degree (molecular weight) of the (meth) acrylate copolymer.

In an embodiment, the (meth) acrylate copolymer (A) may have a weight average molecular weight (Mw) of 800,000 to 2,500,000 g / mol, such as 1,300,000 to 2,200,000 g / mol, specifically 1,500,000 to 2,000,000 g / mol have. Within the above range, the durability of the pressure-sensitive adhesive composition can be improved, and the decrease in productivity during coating can be suppressed. Here, the weight average molecular weight of the (meth) acrylate copolymer (A) can be easily controlled by appropriately adjusting the polymerization initiator used in the polymerization reaction described later, reaction conditions such as the reaction temperature and the reaction time, and the like. For example, when the amount of the polymerization initiator is increased, the weight average molecular weight tends to decrease. Conversely, if the amount of the polymerization initiator is decreased, the weight average molecular weight tends to become larger. Further, in the present specification, the weight average molecular weight adopts the value measured by the method described in the embodiment.

As the (meth) acrylate copolymer (A) described above, only one kind of copolymer may be used alone, or two or more kinds of copolymers may be used in combination.

In the embodiment, the (meth) acrylate copolymer (A) may be prepared by a solution polymerization method, a bulk polymerization method, an emulsion polymerization method, a suspension polymerization method, a reverse phase suspension polymerization method, a thin film polymerization method, Can be produced by a known polymerization method. Examples of the polymerization control method include an adiabatic polymerization method, a temperature control polymerization method, an isothermal polymerization method and the like. As the polymerization initiator, any of a thermal polymerization initiator and a photopolymerization initiator may be used. In addition to the method of initiating polymerization by a polymerization initiator, a method of initiating polymerization by irradiation with active energy rays such as radiation, electron beam, and ultraviolet ray may be used. Of these, a solution polymerization method using a thermal polymerization initiator, a bulk polymerization method using a photopolymerization initiator, and the like are preferable because the molecular weight can be easily controlled and less impurities are generated.

The solution polymerization method using the above-mentioned thermal polymerization initiator is a method in which an alkyl (meth) acrylate monomer which is a raw material of the (meth) acrylate copolymer (A) and an alkyl (meth) (a3) adding a thermal polymerization initiator to a raw material monomer solution containing another monomer, and performing a polymerization reaction. More specifically, 0.01 to 1 part by weight of a thermal polymerization initiator is added to 100 parts by weight of the total amount of raw monomers by using ethyl acetate, toluene, methyl ethyl ketone or the like as a solvent, At 90 占 폚 (or 60 to 90 占 폚) for 3 to 10 hours.

Examples of the thermal polymerization initiator include azo compounds such as 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis (2-methylbutyronitrile), azobiscyano valeric acid, Bis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2'- azobis Azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis [N- Azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride (2,2'-azobis Azo bis [2- (2-imidazolin-2-yl) propane] disulfate dihydrate, 2,2'-azobis (2-methylpropionamidine) dihydrochloride, Azobis [2- (2-imidazolin-2-yl) propane], 2, 2'-azobis [N- (2- carboxyethyl) -2- methylpropionamidine] hydrate, 2'-azobis (1- Amino-1-pyrrolidino-2-methylpropane) dihydrochloride, and 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide]; butyl peroxybenzoate, tert-butyl peroxy-2-ethyl hexanoate, di-tert-butyl peroxide, cumene hydroxycarperoxide, benzoyl peroxide, tert- butyl Organic peroxides such as hydroperoxide; Inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate. These thermal polymerization initiators may be used alone, or two or more of them may be used in combination.

As the bulk polymerization method using the photopolymerization initiator, for example, a raw monomer and a photopolymerization initiator are added, the active energy ray is irradiated under a nitrogen atmosphere at a reaction initiation temperature of 20 to 35 ° C, (Meth) acrylate copolymer (A) is obtained by, for example, introducing air into the reaction system when the temperature is raised from 5 to 15 ° C from the initiation temperature, thereby stopping the reaction.

Examples of the active energy ray used in the bulk polymerization method include ultraviolet rays, laser rays, alpha rays, beta rays, gamma rays, X rays, electron beams, and the like. Ultraviolet rays are suitably used from the viewpoints of advantages of controllability and handling, and cost. Specifically, ultraviolet rays having a wavelength of 200 to 400 nm can be used. Here, the ultraviolet light can be irradiated using a light source such as a high-pressure mercury lamp, a microwave excitation lamp, a chemical lamp, or a black light. The illuminance may be 3.2 to 5.6 mW / cm < ² >.

Examples of the photopolymerization initiator include acetophenone, 3-methylacetophenone, benzyldimethylketal, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1- (4-isopropylphenyl) Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one, 2-hydroxy-2-methyl- Acetophenones such as propan-1-one; Benzophenones including benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone; Benzoin ethers such as benzoin propyl ether and benzoin ethyl ether; Thioxanthones such as 4-isopropylthioxanthone; 1-hydroxycyclohexyl phenyl ketone, xanthone, fluorenone, camphorquinone, benzaldehyde, anthraquinone, and the like. These photopolymerization initiators may be used alone, or two or more of them may be used in combination.

A commercially available product can be used as the photopolymerization initiator. For example, IRGACURE TM 184, 819, 907, 651, 1700, 1800, 819, 369, 261, DAROCUR TMO, DAROCURE TM 1173 (Manufactured by BASF Japan Co., Ltd.), EZACURE (registered trademark) KIP150, TZT (manufactured by DKSH Japan KK), KAYACURE (registered trademark) BMS, DMBI Manufactured by Nippon Kayaku Co., Ltd.).

The amount of the photopolymerization initiator to be used may be 0.0005 to 1 part by weight, specifically 0.002 to 0.5 part by weight based on 100 parts by weight of the total amount of the starting monomer.

In order to control the molecular weight of the (meth) acrylate copolymer (A), a chain transfer agent may also be used. For example, there may be mentioned methyl mercaptan, t-butyl mercaptan, decylmercaptan, benzyl mercaptan, stearyl mercaptan, n-dodecylmercaptan, t-dodecylmercaptan, mercaptoacetic acid, Mercaptans such as 2-ethylhexyl thioglycol and octyl thioglycolate; Alcohols such as methanol, ethanol, propanol, n-butanol, isopropanol, t-butanol, hexanol, benzyl alcohol and allyl alcohol; Halogenated hydrocarbons such as chloroethane, fluoroethane and trichlorethylene; Carbonates such as acetone, methyl ethyl ketone, cyclohexanone, acetophenone, acetaldehyde, propionaldehyde, n-butylaldehyde, furfural, benzaldehyde and the like; Methyl-4-cyclohexene-1,2-dicarboxylic acid anhydride, and? -Methylstyrene. These may be used alone, or two or more kinds may be used in combination.

(B) peroxide

The pressure-sensitive adhesive composition for an optical film according to the present invention comprises a peroxide (B) as an essential component. As used herein, "peroxide" refers to a compound that contains a peroxide structure " -O-O- " in the molecular structure. The peroxide (B) may be one having both functions as a crosslinking agent, a polymerization initiator, or both.

In the specific examples, the peroxide (B) is not particularly limited, but in consideration of workability and stability, the one minute half-life temperature is 80 to 160 캜, such as 80 to 140 캜, specifically 80 to 125 캜, 90 to 125 ° C can be used. Here, "half-life period of peroxide" is an index indicating the rate of decomposition of peroxide, which means the time until the residual amount of peroxide becomes half. The decomposition temperature for obtaining a half-life at a certain time and the half-life time at a certain temperature are described in the manufacturer's catalog and are described in, for example, Nippon Oil Co., Ltd., Organic Peroxide Catalog No. 9 (May 2003) .

In one embodiment, the peroxide is at least one selected from the group consisting of diisopropyl peroxydicarbonate (1 minute half life temperature 88.3 占 폚), bis (2-ethylhexyl) peroxydicarbonate (1 minute half life temperature 90.6 占 폚) tert-butylcyclohexyl) peroxydicarbonate (1 minute half life temperature 92.1 占 폚), bis-sec-butyl peroxydicarbonate (1 minute half life temperature 92.4 占 폚), t-butyl peroxyneodecanoate (Half-life temperature of 103.5 ° C), t-hexyl peroxypivalate (one minute half life temperature 109.1 ° C), t-butyl peroxypivalate (one minute half life temperature 110.3 ° C), dilauroyl peroxide (Half-life temperature for one minute: 117.4 占 폚), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (half-life temperature for one minute: 124.3 占 폚), bis (4-methylbenzoyl) peroxide (1 minute half-life temperature 128.2 占 폚), dibenzoyl peroxide (benzoyl peroxide) Temperature 130.0 占 폚) and t-butyl peroxybutyrate (1 minute half-life temperature 136.1 占 폚). For example, diisopropyl peroxydicarbonate having excellent crosslinking reaction efficiency, bis (4-t-butylcyclohexyl) peroxydicarbonate, di rauroyl peroxide, dibenzoyl peroxide and the like can be used. From the viewpoint of the decomposition temperature, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, and dilauroyl peroxide can be used. These may be used alone or in combination of two or more in view of controlling the reactivity. When used in combination of two or more, a combination of bis (4-t-butylcyclohexyl) peroxydicarbonate and dilauryl peroxide can be used.

The peroxide may be used in combination or a commercially available product may be used. As a commercial product, for example, "PEROIL (registered trademark) IB" (one minute half life temperature 85.1 DEG C) and PERCUMYL (registered trademark) ND (one minute half life temperature 94.0 (A half-life temperature of 94.0 ° C for one minute), "Peroil (registered trademark) IPP" (one minute half life temperature 88.3 ° C), "Peroil (registered trademark) SBP" (A half-life half-life temperature of 92.4 占 폚), PEROCTA 占 ND (one minute half life temperature 92.4 占 폚), Perloil 占 TCP (one minute half life temperature 92.1 占 폚) PERHEXYL (registered trademark) ND "(one minute half life temperature 100.9 ° C) and" PERBUTYL (registered trademark) ND "(one minute half life temperature 90.6 ° C) (Half-life temperature 103.5 ° C), "Perbutyl TM NHP" (one minute half life temperature 104.6 ° C), "Perhexyl TM PV" (one minute half life temperature 109.1 ° C) (1-minute half-life temperature 110 ° C), "Peroil (registered trademark) 355" (one minute half life temperature 112.6 ° C), "Peroil (registered trademark) L" (one minute half life temperature 116.4 ° C) (1 minute half-life temperature 124.3 占 폚), "Peroil (registered trademark) SA" (one minute half life temperature 131.8 占 폚), "PERHAXA 占 25O" (Half-life temperature 132.6 ° C for one minute), "NYPER PMB" (one minute half life temperature 128.2 ° C), "Perbutyl O" (one minute half life temperature 134.0 (Half-life temperature of 131.0 ° C for one minute), "Knife (registered trademark) BMT" (one minute half life temperature 131.1 ° C) 131.1 " C), " PERHEXA (registered trademark) MC " (1 minute half life temperature 142.1 DEG C, PERHEXA TMH (1 minute half life temperature 147.1 DEG C) Minute half-life temperature of 149.2 ° C), " Quot; C (registered trademark) C " (one minute half life temperature 153.8 占 폚), PERTETRA 占 A (one minute half life temperature 153.8 占 폚) (Per minute), " PERBEX (registered trademark) 25Z ", " PERBUTE (registered trademark) (Half-life temperature for one minute 158.2 占 폚), "Perbutyl (registered trademark) A" (one minute half life temperature 159.9 占 폚) and "Perhexa 占 22" (one minute half life temperature 159.9 占 폚) .

In the specific examples, the content of the peroxide (B) in the pressure-sensitive adhesive composition for an optical film is from 2 parts by weight to 10 parts by weight, for example from 2 to 5 parts by weight, relative to 100 parts by weight of the (meth) Parts by weight, specifically 2 to 3 parts by weight. Within the above range, the pressure-sensitive adhesive composition for an optical film may have excellent heat durability at high temperature, liquid stability, and the like.

(C) Crosslinking agent

The pressure-sensitive adhesive composition for an optical film according to the present invention contains, as an essential component, a cross-linking agent (C) other than the peroxide (B). The crosslinking agent (C) reacts with the (meth) acrylate copolymer (A) to form a crosslinked structure. The crosslinking agent (C) can contribute mainly to adhesiveness (stickiness) and durability in the pressure-sensitive adhesive composition for an optical film. Here, the term "other than peroxide" is used to distinguish it from the above-mentioned "peroxide (B)".

In an embodiment, the crosslinking agent may be an isocyanate crosslinking agent, a carbodiimide crosslinking agent, an oxazoline crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, or a combination thereof.

Examples of the isocyanate crosslinking agent include triaryl isocyanurate, dimeric acid diisocyanate, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6- (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), 1,4-phenylene diisocyanate, xylylenedi Aromatic diisocyanates such as isocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolylidine diisocyanate (TODI) and 1,5-naphthalene diisocyanate (NDI); Aliphatic diisocyanates such as hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate and norbornane diisocyanatomethyl (NBDI); Alicyclic diisocyanates such as trans cyclohexane 1,4-diisocyanate, isophorone diisocyanate (IPDI), H6-XDI (hydrogenated XDI) and H12-MDI (hydrogenated MDI); Carbodiimide-modified diisocyanates of the above diisocyanates; Or an isocyanurate-modified diisocyanate thereof; And the like. Adducts of the isocyanate compound and a polyol compound such as trimethylolpropane, and a buretecene isocyanurate of the isocyanate compound can also be suitably used. The isocyanate crosslinking agent may be a synthesized product, or a commercially available product may be used. Commercially available products include CORONATE (R) L, CORONATE (R) HL, CORONATE (R) HX, CORONATE (R) 2030, CORONATE (R) 2031 TAKENATE (registered trademark) D-102, TOKENATE (registered trademark) D-110N, TOKENATE (registered trademark) D-200, TOKENATE (registered trademark) D-202 (DURANATE 占 24A-100, DURANATE 占 TPA-100, DURANATE 占 TKA-100, DURANATE 占 P301-75E (product of Mitsui Chemicals, Inc.) Duraate (registered trademark) E402-90T, Duraanate (registered trademark) E405-80T, Duraanate (registered trademark) TSE-100, Duraanate (registered trademark) D- (Manufactured by Asahi Kasei Chemical Co., Ltd.), SUMIDULE (registered trademark) N-75, N-3200 and N-3300 (manufactured by Sumika Bayer Urethane Co., Ltd.) Can.

These isocyanate crosslinking agents can be used in the form of an isocyanate compound which is not blocked and can be used in the form of a block isocyanate compound obtained by reacting with a blocking agent for protecting an isocyanate group. As the block isocyanate compound, those obtained synthetically or commercially available products can be used. Examples of commercially available products include DURANATE TM MF-B60X (block 1,6-hexamethylene diisocyanate), DURANATE TM MF-K60X (block 1,6-hexamethylene diisocyanate) manufactured by Asahi Kasei Chemical Co., 2503, 2507, 2513, 2515, MILLIONATE (registered trademark) MS-50 manufactured by Nippon Polyurethane Kogyo Co., Ltd., Takenate (registered trademark) B B-842N (block 1,3-bis (isocyanatomethyl) cyclohexane), B-846N (isocyanatomethyl) cyclohexane) (Block 1,3-bis (isocyanatomethyl) cyclohexane), B-874N (block isophorone diisocyanate), B-882N (block 1,6-hexamethylene diisocyanate), Dainippon Ink, BURNOCK (R) D-500 (blocky tolylene diiso ELASTRON (registered trademark) BN-P17 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (Blocks 4 and 4), D-550 (block 1,6-hexamethylene diisocyanate) BN-04, BN-08, BN-44 and BN-45 (above, block urethane-modified polyisocyanate). From the viewpoint of further improving the durability of the pressure-sensitive adhesive composition, the isocyanate-based crosslinking agent is preferably used in the form of an isocyanate compound which is not blocked.

As the carbodiimide crosslinking agent, for example, a high molecular weight polycarbodiimide produced by a decarbonic acid condensation reaction of a diisocyanate in the presence of a carbodiimidization catalyst may be used.

Examples of the diisocyanate to be provided in the decarbonation condensation reaction include 4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl- , 4'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate, 2,4-tolylene diisocyanate, 6-tolylene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, tetramethyl xylylene diisocyanate and the like.

Examples of the carbodiimidation catalyst used in the decarbonation condensation reaction include 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phosphorene- 3-methyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide and their 3-phosphorene isomers and the like.

The above-mentioned high molecular weight polycarbodiimide may be synthesized, or a commercially available product may be used. As a commercial product, CARBODILITE (registered trademark) series manufactured by Nisshinbo Chemical Co., Ltd. can be used. Of these, Carbodite (registered trademark) V-01, V-03, V-05, V-07 and V-09 are preferable because of their excellent compatibility with organic solvents.

Examples of the oxazoline crosslinking agent include an oxazoline group-containing acrylic / styrene type polymer containing a main chain composed of an acrylic skeleton or a styrene skeleton and having an oxazoline group in the side chain of the main chain; An oxazoline group-containing polymer called an oxazoline group-containing acrylic polymer having an oxazoline group in the side chain of the main chain and a main chain made of an acrylic skeleton.

Examples of the oxazoline group include a 2-oxazoline group, a 3-oxazoline group, and a 4-oxazoline group.

In addition, the oxazoline group-containing polymer may include a polyoxyalkylene group in addition to the oxazoline group.

Examples of the oxazoline group-containing polymer include EPOCROS (registered trademark) WS-300, EPOCROS (registered trademark) WS-500, EPOCROS (registered trademark) WS- An oxazoline group-containing acrylic polymer such as 700; An oxazoline group-containing acrylic / styrenic polymer such as Epocross (registered trademark) K-1000 series and Epochros (registered trademark) K-2000 series manufactured by Nippon Shokubai Co., Etc. may be used.

As the epoxy cross-linking agent, a known epoxy cross-linking agent may be used without limitation. Commercially available products include TETRAD-C, TETRAD-X manufactured by Sukagaku KK, Adekaresin EPU series manufactured by Adeka Corporation, Adeka Resin EPR series, and CELLOXIDE manufactured by Daicel Inc. Can be used. Particularly, liquid epoxy resins such as these have an advantage that they can be easily mixed when the pressure-sensitive adhesive composition for an optical film is produced.

As the aziridine crosslinking agent, a polyfunctional aziridine compound having a plurality of aziridine rings can be used. As the multifunctional aziridine compound, for example, compounds disclosed in U.S. Patent No. 3,225,013, U.S. Patent No. 4,490,505, U.S. Patent No. 5,534,391, Japanese Patent Laid-Open No. 2003-104970, and the like can be used.

As a commercial product of the aziridine crosslinking agent, for example, CHEMITITE (registered trademark) PZ-33 and Chemitate (registered trademark) DZ-22E available from Nippon Shokubai Co., Ltd. can be used.

In a specific example, when the crosslinking agent (C) is used in combination of two or more of isocyanate crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, epoxy crosslinking agents and aziridine crosslinking agents, two or more kinds of crosslinking agents For example, two kinds of isocyanate crosslinking agents may be used in combination. One or more crosslinking agents of different types (for example, isocyanate crosslinking agent and carbodiimide crosslinking agent) may be combined.

In a specific example, the content of the crosslinking agent (C) in the pressure-sensitive adhesive composition for an optical film is 0.001 to 2 parts by weight, for example, 0.01 to 1.5 parts by weight, relative to 100 parts by weight of the (meth) acrylate copolymer (A) , Specifically 0.05 to 1 part by weight. In the above range, the pressure-sensitive adhesive composition can form a sufficient crosslinking structure, can not be excessively cured, and can have excellent durability.

(D) Silane coupling agent

The pressure sensitive adhesive composition for an optical film according to one embodiment of the present invention may further comprise (D) a silane coupling agent. The silane coupling agent (D) can improve the durability and the like of the pressure-sensitive adhesive composition for an optical film, and when the object to be delivered is glass, adhesion with glass can be improved. As used herein, the term "silane coupling agent" means a compound having no siloxane bond (Si-O-Si bond) and having two or more reactive groups in the molecule.

Examples of the silane coupling agent (D) include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, ethyltrimethoxysilane, diethyldiethoxysilane, n-butyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, phenyltrimethoxysilane, Vinyl trichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (? -Methoxyethoxy) silane,? - (3,4-epoxy Cyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane,? -Glycidoxypropyltrimethoxysilane,? -Glycidoxypropyltriethoxysilane,? -Methacryloxypropylmethyldimetate Methoxypropyltrimethoxysilane,? -Methacrylate,? -Methacryloxypropyltrimethoxysilane, ? - (aminoethyl) -? - aminopropylmethyldimethoxysilane, N-β-dodecyldimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, N- (Aminoethyl) -? - aminopropyltrimethoxysilane, N -? - (aminoethyl) -? - aminopropyltriethoxysilane,? -Aminopropyltrimethoxysilane,? -Aminopropyltriethoxysilane, N-phenyl-gamma -aminopropyltrimethoxysilane, gamma -chloropropyltrimethoxysilane, gamma-mercaptopropyltrimethoxysilane, gamma -mercaptopropylmethyldimethoxysilane, bis- (3- [ Ethoxysilyl] propyl) tetrasulfide, and? -Isocyanatopropyltriethoxysilane. Further, a silane coupling agent having a functional group such as an epoxy group (glycidoxy group), an amino group, a mercapto group and a (meth) acryloyl group, a silane coupling agent containing a functional group having reactivity with these functional groups, other coupling agents, polyisocyanates May be reacted at an arbitrary ratio with respect to each functional group to obtain a hydrolyzable silyl group-containing compound.

The silane coupling agent (D) may be synthesized or used as a commercial product. The commercial products include KBM-303, KBM-403, KBE-402, KBE-403, KBE-502, KBE-503, KBM-5103, KBM-573, KBM-802, KBM-803, KBE- (Manufactured by Shin-Etsu Chemical Co., Ltd.), and the like.

The silane coupling agent (D) may be used singly or in combination of two or more.

In the specific example, the content of the silane coupling agent (D) in the pressure-sensitive adhesive composition for an optical film is 0.001 to 10 parts by weight, for example, 0.005 to 10 parts by weight, 5 parts by weight, specifically 0.01 to 3 parts by weight, specifically 0.01 to 1 part by weight. In the above range, the durability and the like of the pressure-sensitive adhesive composition can be excellent, and deterioration of the heating foaming derived from the low molecular weight compound can be reduced.

(E) Silicate oligomer

The pressure sensitive adhesive composition for an optical film according to an embodiment of the present invention may further comprise (E) a silicate oligomer. The silicate oligomer can contribute mainly to the improvement of the lithography workability in the pressure-sensitive adhesive composition for an optical film. For example, the silicate oligomer may be represented by the following formula (1).

[Chemical Formula 1]

R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a phenyl group, X ₁ and X ₂ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a phenyl group, , and n is an integer of 1 to 100, for example, an integer of 2 to 100.

Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec- tert-pentyl group, neopentyl group, n-hexyl group, cyclohexyl group and the like.

Examples of the alkyl group having 1 to 20 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-hexyl group, n-octyl group, 2-ethylhexyl group, n-decyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like.

In embodiments, R ₁ and R ₂ may each independently be a methyl group, an ethyl group, a n-propyl group, or a phenyl group, and X ₁ and X ₂ may each independently be a methyl group, an ethyl group, have.

In the specific examples, when the silicate oligomer is a methyl silicate oligomer in which R ₁ , R ₂ , X ₁ and X ₂ are both methyl groups, it is possible to more easily achieve both durability and reworkability of the pressure sensitive adhesive composition (pressure sensitive adhesive layer) have. As the silicate oligomer, only one of the compounds shown above may be used alone, or two or more of them may be used in combination.

In embodiments, the silicate oligomer (E) may have a weight average molecular weight of 300 to 30,000 g / mol, such as 500 to 25,000 g / mol, specifically 600 to 5,000 g / mol. Within the above range, it is easy to ensure the workability and durability of the pressure-sensitive adhesive composition.

In the specific example, the content of the silicate oligomer (E) in the pressure-sensitive adhesive composition for an optical film is 0.01 to 50 parts by weight, for example, 0.3 to 10 parts by weight, relative to 100 parts by weight of the (meth) acrylate copolymer (A) , Specifically 0.5 to 5 parts by weight. The durability and the like of the pressure-sensitive adhesive composition can be excellent in the above-mentioned range, and the reworkability and the durability can be made compatible with each other easily.

(F) Solvent

The pressure-sensitive adhesive composition for an optical film according to one embodiment of the present invention may further comprise a solvent, if necessary. Examples of the solvent include esters such as ethyl acetate and n-butyl acetate; Aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; Alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; And organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. These solvents may be used alone, or two or more of them may be used in combination.

In the specific example, the content of the solid content in the pressure-sensitive adhesive composition for an optical film is not particularly limited, but may be 10 to 50% by weight, for example, 12 to 30% by weight based on 100% by weight of the total amount of the pressure- have. Within the above range, the coatability and the productivity can be excellent.

The pressure-sensitive adhesive composition for an optical film according to one embodiment of the present invention may contain a crosslinking accelerator, an antioxidant, a filler, a coloring agent (pigment, dye and the like), an ultraviolet absorber, an antioxidant, a chain transfer agent, a plasticizer, (Other additives) such as an antistatic agent can be contained within a range that does not impair the effect of the present invention.

In an embodiment, the pressure-sensitive adhesive composition for an optical film according to one embodiment of the present invention comprises a (meth) acrylate copolymer (A), a peroxide (B), and a silane coupling agent (D) , A silicate oligomer (E), a solvent (F) and / or other additives. The mixing order of the components is not particularly limited, and can be suitably adjusted by those skilled in the art.

The above-described pressure-sensitive adhesive composition for an optical film of the present invention is suitable for various uses. For example, it can be used for an optical member such as an optical film. In particular, it can be applied to a thin type adhesive optical film used in a large liquid crystal panel. Examples of such an optical film include a polarizing plate, a phase difference plate as a coloring preventing film, an optical compensation film such as a viewing angle enlarging film for improving the viewing angle of a liquid crystal monitor, a luminance improving film for enhancing contrast of a display, .

In the present invention, the form of the pressure-sensitive adhesive layer formed by the above-mentioned pressure-sensitive adhesive composition for an optical film, the form of the optical member in which the pressure-sensitive adhesive layer is formed on the optical film, the form in which the optical film is a polarizer, A form applied to an image display device such as a display device, an organic EL display device, a plasma display (PDP), a curved surface display, or a flexible display can be provided. Each will be described below.

For optical film The pressure-

The pressure-sensitive adhesive layer for an optical film according to one embodiment of the present invention is formed from the pressure-sensitive adhesive composition for an optical film.

In a specific example, the thickness of the pressure-sensitive adhesive layer (thickness after drying) can be suitably set by a person skilled in the art according to the use of the pressure-sensitive adhesive, but is preferably 1 to 200 μm, for example 3 to 75 μm, specifically 5 to 40 μm, Specifically, 7 to 35 mu m, specifically 10 to 30 mu m. The balance between the durability and the adhesive property of the adhesive layer in the above range can be excellent.

In an embodiment, the gel fraction of the pressure-sensitive adhesive layer may be 40 to 95%, for example 50 to 90%, specifically 60 to 85%. In the above range, punching or slit processing can be performed quickly, scratches on the pressure-sensitive adhesive layer immediately after drying can be prevented, durability can be excellent, Can be prepared. The gel fraction can be controlled by adjusting the content of the crosslinking agent or peroxide. Further, in this specification, the gel fraction adopts the value measured by the method described in the embodiment.

For optical film Method for producing pressure-sensitive adhesive layer

The pressure-sensitive adhesive layer for an optical film according to the present invention is obtained by applying the above-mentioned pressure-sensitive adhesive composition for an optical film onto a release sheet subjected to a peeling treatment; And applying the applied pressure-sensitive adhesive composition for an optical film to a crosslinking reaction.

In the specific example, when the pressure-sensitive adhesive composition is used in an optical film, a pressure-sensitive adhesive layer can be formed by directly coating the pressure-sensitive adhesive composition on the optical film. However, after the pressure-sensitive adhesive composition is applied on a film having releasability to form a pressure- , It is preferable to use it by transferring it to various optical films. In addition, a film having releasability with the pressure-sensitive adhesive layer thus produced can be wound together in a manufacturing process to form a roll, and after cutting or processing as required, the pressure-sensitive adhesive layer is adhered to various optical films or liquid crystal panels , The film having the corresponding releasability can be removed and used. Further, until the pressure-sensitive adhesive layer is used in an optical member or the like, a film having releasability can serve to protect the pressure-sensitive adhesive layer. In this specification, a film having such releasability is also referred to as a releasing sheet (separator).

In the specific examples, the constituent material of the release sheet (separator) may include plastic films such as polyethylene, polypropylene, polyethylene terephthalate and polyester film, porous materials such as paper, cloth, and nonwoven fabric, net, Metal foil, and laminate of these, and the like. Of these, a plastic film is suitably used because of its excellent surface smoothness. The thickness of the release sheet may be 5 to 200 mu m, for example, 5 to 100 mu m. If necessary, the release sheet may be subjected to antistatic treatment such as releasing treatment with a silicone, fluorine, long chain alkyl or fatty acid amide releasing agent or silica powder, antifouling treatment, coating type, kneading injection type, . Particularly, the releasability from the pressure-sensitive adhesive layer can be further improved by suitably carrying out a surface treatment such as silicone treatment, long-chain alkyl treatment or fluorine treatment on the surface of the release sheet.

In a specific example, the method of applying the pressure-sensitive adhesive composition on a release sheet obtained by removing the pressure-sensitive adhesive composition is not particularly limited and various known methods can be used. For example, an extrusion coating method using roll coats, kiss roll coats, gravure coats, reverse coats, roll brushes, spray coats, dip roll coats, bar coats, knife coats, air knife coats, curtain coats, lip coats, Can be exemplified.

In the specific example, the heat treatment step is not only for drying and removing the solvent in the coating film obtained by coating, but also for the purpose of performing the crosslinking reaction of the above-mentioned pressure-sensitive adhesive composition for an optical film. The temperature for the heat treatment may be 40 to 150 占 폚, for example, 50 to 130 占 폚, specifically 80 to 120 占 폚. In the above range, a pressure-sensitive adhesive layer having excellent adhesive properties can be obtained. Further, the heat treatment time can be suitably set by a person skilled in the art, but may be 5 seconds to 20 minutes, for example 5 seconds to 10 minutes, specifically 10 seconds to 5 minutes. In the above range, a pressure-sensitive adhesive layer having excellent adhesive properties can be obtained.

In the specific example, the heat treatment means is not particularly limited and various known methods can be used. For example, there are a parallel drying method in which hot wind is blown in the film transport direction in the upper and lower directions, a counter flow drying method in which hot wind is blown in the film transport direction in the upper and lower direction, And a float drying method for blowing hot air can be used.

Optical member

The optical member according to the present invention comprises the aforementioned pressure-sensitive adhesive layer for an optical film; And a first optical film formed on one side of the pressure-sensitive adhesive layer for the optical film. Further, the optical member according to one embodiment of the present invention may further include (install) a glass or a second optical film on the opposite side of the surface of the pressure sensitive adhesive layer on which the first optical film is provided. Here, the "first optical film" and "second optical film" may be films having the same constitution (material, function, and the like), or may be films having different constructions. Further, in the present invention, the first optical film (or the second optical film) is also provided as a polarizing plate.

In the specific examples, the above-described pressure-sensitive adhesive composition can be directly applied to one side or both sides of the optical film to form a pressure-sensitive adhesive layer. However, for the above-mentioned reason, It is preferable to use it by transferring it to the surface. Before the transfer, the surface of the optical film may be subjected to a treatment such as corona treatment, plasma treatment, formation of an easy-to-adhere treatment layer, formation of an antistatic layer and the like depending on the material thereof. Further, the surface of the pressure-sensitive adhesive layer can be subjected to an easy adhesion treatment. From the viewpoint of strongly bonding the optical film and the pressure-sensitive adhesive layer, it is preferable that an easy-to-adhere treatment layer is formed between the optical film and the pressure-sensitive adhesive layer for an optical film.

The optical member according to one embodiment of the present invention may further include at least one easy-adhesion treatment layer between the first optical film and the pressure-sensitive adhesive layer for the optical film. Wherein the adhesive layer facilitates adhesion between the optical film and the pressure-sensitive adhesive layer. In a preferred embodiment, the optical member has a first adhesive layer and a second adhesive layer between the first optical film and the pressure- 2 adhesion facilitating layer, wherein the first optical film is adjacent to the first adhesive facilitating layer, and the pressure-sensitive adhesive layer for the optical film is adjacent to the second adhesive facilitating layer.

In an embodiment, the adhesion facilitating layer can be formed by treating a surface of a member in contact with the pressure-sensitive adhesive layer, such as a corona treatment or a plasma treatment, and a separate member such as a primer layer is formed on the surface of the member in contact with the pressure- It can be done.

As the material constituting the primer layer, it is preferable to form a film having good cohesion with a member in contact with the primer layer and having excellent cohesive strength. For example, various polymers, sols of metal oxides, silica sol, and the like are used, among which polymers can be preferably used. The primer layer may have an antistatic function.

Examples of the polymers constituting the primer layer include oxazoline group-containing polymers, polyurethane resins, polyester resins, polymers containing an amino group in the molecule, and the like. For example, an oxazoline group-containing polymer can be used. Commercially available oxazoline group-containing polymers may be used. For example, Epochros (registered trademark) series (e.g., Epochros (registered trademark) WS700) manufactured by Nihon Shokubu Co., Ltd., and the like can be cited. As the polyurethane resin, polyester resin, polymers containing an amino group in the molecule, and the like, those disclosed in paragraphs [0107] to [0113] of Japanese Patent Laid-Open Publication No. 2011-105918 can be suitably used.

The primer layer can be formed, for example, by applying a primer layer material by a coating method such as a coating method, a dipping method, or a spraying method, followed by drying.

The thickness of the primer layer may be 10 to 5,000 nm, for example, 50 to 500 nm. Within the above range, the adhesive layer can exhibit sufficient strength and adhesion, and optical properties can be maintained.

In the present invention, the optical film (the first optical film and / or the second optical film) may be at least a polarizing film (polarizing plate), a retardation film (retardation plate), a polarizing film or a retardation film, And a protective layer, an optical compensation film such as a cover film, a transparent conductive film, a window film, a viewing angle enlarging film for improving the viewing angle of a liquid crystal monitor, a luminance improving film for enhancing the contrast of a display, It may be laminated. Among them, a polarizing film, an optical compensation film, or a film formed by laminating a polarizing film and an optical compensation film is preferable.

In a specific example, the polarizing plate suitable for the optical film can be produced by bonding a protective film and a polarizer using an adhesive according to a conventionally known method, followed by heat drying or curing with ultraviolet rays or electron beams. The applied adhesive is cured by drying, ultraviolet rays, electron beams or the like to exhibit adhesiveness to constitute an adhesive layer.

The polarizer is not particularly limited and a known polarizer can be used. For example, a hydrophilic polymer film such as a polyvinyl alcohol film, a partially foamed polyvinyl alcohol film, and an ethylene / vinyl acetate copolymerization system partially saponified film may be produced by adsorbing a dichroic material such as iodine or a dichroic dye, , A polyene-based oriented film such as a dehydrated product of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride can be exemplified. Among them, a polarizer produced by dyeing a polyvinyl alcohol film having an average polymerization degree of 2,000 to 2,800 and a degree of saponification of 90 to 100% by mole with iodine and uniaxially stretching 3 to 8 times is preferable. Specifically, the polarizer may be one obtained by immersing a polyvinyl alcohol film in an aqueous solution of iodine, dyeing it, and stretching it. The step of immersing in an aqueous solution of iodine may be carried out by immersing in an aqueous solution containing 0.1 to 10% by weight of iodine and / or potassium iodide. If necessary, it may be immersed in an aqueous solution of boric acid or potassium iodide at a temperature of 50 to 70 DEG C, or may be immersed in water at 25 to 35 DEG C in order to prevent washing or staining unevenness. Stretching can be carried out after dyeing with iodine, or during dyeing, followed by stretching and dyeing with iodine. After dyeing and stretching, it may be washed with water and dried at 35 to 55 ° C for about 1 to 10 minutes. As such a polarizer, various commercially available products may be used. The thickness of the polarizer is not particularly limited, but may be 5 to 80 탆.

In an embodiment, the optical film may be a polarizing plate having one side thereof protected from the viewpoint of requiring a higher degree of durability. The protective method is not particularly limited, and a known method such as bonding a protective film can be suitably employed. As the protective film, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is preferable. Examples of the resin include acrylic resin, cellulose resin such as triacetyl cellulose, polyester resin such as polyethylene terephthalate and polyethylene naphthalate, polyether sulfone resin, polysulfone resin, polycarbonate resin, polyamide resin , A polyimide resin, a polyolefin resin, a (meth) acrylic resin such as polymethyl methacrylate, a cyclic polyolefin resin (norbornene resin), a polyarylate resin, a polystyrene resin, a polyvinyl alcohol resin, Resins, and mixtures thereof.

On one side of the polarizer, a transparent protective film is bonded by an adhesive, and on the other side, a thermosetting resin such as a (meth) acrylic type, urethane type, acrylic urethane type, epoxy type, A curable resin can be used.

In a specific example, the thickness of the polarizing plate is not particularly limited, but may be generally 20 to 200 占 퐉, for example, 20 to 100 占 퐉, specifically 20 to 75 占 퐉, specifically 20 to 50 占 퐉. In the above range, the thin polarizing plate can more remarkably exhibit the effect of the pressure-sensitive adhesive composition of the present invention.

In a specific example, the polarizing plate can be produced, for example, by applying an adhesive to one or both of the protective film and the polarizer, and then joining the polarizer and the protective film with a roll laminator or the like. After bonding, the curing process may be carried out by moderately drying, ultraviolet ray, electron beam, or the like. The adhesive is preferably applied so that the thickness of the adhesive layer after drying is 10 to 300 nm. Further, the adhesive may be appropriately adopted from known ones in accordance with the material of the polarizer. For example, when a polyvinyl alcohol-based film is used as the polarizer, an acrylic, epoxy, or acrylic-epoxy system may be used as the polyvinyl alcohol-based adhesive or the ultraviolet-curable adhesive. The thickness of the adhesive layer is preferably 10 to 200 nm for the polyvinyl alcohol adhesive and 0.2 to 10 m for the ultraviolet curable adhesive in order to obtain a uniform in-plane thickness and sufficient adhesive strength.

In an embodiment, an adhesive type polarizing plate having a pressure-sensitive adhesive layer formed on the polarizing plate may be used. The construction and manufacturing of the adhesive polarizing plate are the same as those in the case of the optical film having the above-mentioned pressure-sensitive adhesive layer, and the description thereof is omitted here.

In an embodiment, the optical member may satisfy the following formulas (1) and (2).

[Formula 1]

0.3? A ₀ ? 2.5

In the formula (1), A ₀ is an optical member attached to a glass plate, autoclaved at 50 ° C and 5 atm for 15 minutes to make a close contact, and then peeled at a peel angle of 180 ° and a peel rate of 300 mm / min. < / RTI > measured in accordance with JIS Z0237 (2009).

[Formula 2]

1.0? A? ₁ ? 3.9

In the formula (2), A ₁ denotes an optical member attached to a glass plate, autoclaved at 50 캜 for 5 minutes under a pressure of 5 atmospheric pressure, and then heated again at 50 캜 for 48 hours. % RH, a peel angle of 180 °, and a peel rate of 300 mm / min, measured in accordance with JIS Z0237 (2009).

Image display device

The image display apparatus according to the present invention comprises at least one optical member. The image display apparatus can be easily manufactured by a method known to a person skilled in the art. Examples of such image display devices include a liquid crystal display device, an organic EL display device, a plasma display (PDP), and the like.

As described above, the pressure-sensitive adhesive composition for an optical film according to the present invention is excellent in durability even in a severe environment (high temperature, high humidity, heat shock) and has a reworkability capable of easily peeling off an optical film from a liquid crystal panel Can be compatible. Further, the liquid crystal panel is scarcely contaminated, and the pull-in resistance at the end portion when the optical member is cut and used is also good. In the present specification means that the pressure-sensitive adhesive layer is peeled from the end (cut surface) of the optical member when the optical member (e.g., a polarizing plate or the like) having the pressure-sensitive adhesive layer using the pressure- It is a characteristic that it is lost. The degree of the pool shortage is evaluated according to the criteria described in the examples.

In addition, the pressure-sensitive adhesive composition for an optical film has excellent handling properties such as no need of aging in the case of producing a pressure-sensitive adhesive layer or an optical member or the like.

Therefore, the optical member using the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition for an optical film can be suitably used for an image display device including a liquid crystal display device. Particularly, it is suitable for a thin image display apparatus.

Hereinafter, the present invention will be described in more detail by way of examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Example

In the following Examples and Comparative Examples, the room temperature was set at 23 DEG C and 55% RH.

Physical property measurement condition

The weight average molecular weight (Mw) and number average molecular weight (Mn) of the (meth) acrylate copolymer (A) were measured using GPC (gel permeation chromatography).

Analyzer: Toso product, HLC-8120GPC

Column: Toso products, G7000H _XL + GMH _XL + GMH _XL

Column size: Each 7.8 mmφ × 30 cm, total 90cm

Column temperature: 40 DEG C

Flow rate: 0.8 ml / min

Injection volume: 100 μl

Eluent: Tetrahydrofuran

Detector: Differential refractometer (RI)

Standard sample: polystyrene.

Hereinafter, specifications of each component used in Examples and Comparative Examples are as follows.

(A) a (meth) acrylate copolymer

(Meth) acrylate copolymers (A1 to A5) prepared in the following Production Examples 1 to 5 were used.

Production Example 1: Preparation of (meth) acrylate copolymer

100 parts by weight of a monomer containing 99% by weight of n-butyl acrylate (BA) and 1% by weight of 4-hydroxybutyl acrylate (4HBA) was added to a four-necked flask equipped with a stirrer, a thermometer, And 0.1 part by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator together with 100 parts by weight of ethyl acetate. Then, nitrogen gas was introduced into the flask with gentle stirring to change the temperature of the liquid in the flask to 55 DEG C And a polymerization reaction was carried out for 5 hours to prepare a solution of the (meth) acrylate copolymer (A1) having a weight average molecular weight (Mw) of 1,900,000 g / mol.

Production Examples 2 to 5: Preparation of (meth) acrylate copolymer

According to the following Table 1, the same procedure as in Production Example 1 was carried out except that the kinds and ratios of the monomers forming the (meth) acrylate copolymer (A), the amount of the polymerization initiator added, and / (Meth) acrylate copolymer (A2 to A5) was prepared. The weight average molecular weights (Mw) of the (meth) acrylate copolymers (A2) to (A5) are shown in Table 1 below.

(A) Composition (% by weight) Mw (g / mol) (a1) (a2) (a3) BA MA 4HBA BzA AA Production Example 1 A1 99 - One - - 1.9 million Production Example 2 A2 95 - 5 - - 1.9 million Production Example 3 A3 97 - One - 2 1.9 million Production Example 4 A4 70 16 One 13 - 1.9 million Production Example 5 A5 95 - - - 5 1.9 million

(Meth) acrylate, (a1): alkyl (meth) acrylate, (a2): hydroxyalkyl (meth) acrylate, , BA: n-butyl acrylate, MA: methyl acrylate, 4HBA: 4-hydroxybutyl acrylate, BzA: benzyl acrylate, AA:

(B) peroxide

(B1) Perlow TCP (bis (4-t-butylcyclohexyl) peroxydicarbonate, 1 minute half-life temperature: 92.1 ° C, manufactured by Nichiyu Corporation) was used.

(B2) perylal L (dilauroyl peroxide, 1 minute half-life temperature: 116.4 ° C, manufactured by Nichiyu Corporation) was used.

(B3) Perloil IPP (manufactured by Nichiyu Corporation) was used.

(B4) per butyl ND (manufactured by Nichiyu Corporation) was used.

(B5) perbutyl PV (manufactured by Nichiyu Corporation) was used.

(B6) perocta O (manufactured by Nichiyu Corporation) was used.

(B7) NYPER BW (manufactured by Nichiyu Corporation) was used.

(B8) NYPER BMT (manufactured by Nichiyu Corporation) was used.

(C) Crosslinking agent

(C1) isocyanate crosslinking agent Takenate (registered trademark) D-110N (75% ethyl acetate solution of trimethylol propane adduct of xylylene diisocyanate, 3 isocyanate groups in one molecule, manufactured by Mitsui Chemicals) was used.

(C2) isocyanate crosslinking agent DURANATE (registered trademark) MF-K60X (1,6-hexamethylene diisocyanate blocked with ethyl acetoacetate, manufactured by Asahi Kasei Chemical Co., Ltd.) was used.

(C3) Carbodiimide crosslinking agent CARBODILITE (registered trademark) V-05 (manufactured by Nisshinbo Chemical Co., Ltd.) was used.

(C4) oxazoline crosslinking agent EPOCROS (registered trademark) WS-500 (manufactured by Nippon Shokubai Co., Ltd.) was used.

(C5) epoxy cross-linking agent TETRAD-X (N, N, N ', N'-tetraglycidyl-m-xyleneamine, manufactured by Mitsubishi Gas Chemical Company) was used.

(C6) aziridine crosslinking agent Chemitate (registered trademark) PZ-33 (2,2-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate] manufactured by Nippon Shokubai Co.) .

(D) Silane coupling agent

KBM-403 (trade name) (3-glycidoxypropyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd.) was used.

(E) Silicate oligomer

Methyl silicate 53A (product of Colcoat Co., Ltd., weight average molecular weight: 900 g / mol) represented by the following formula (1a) was used.

[Formula 1a]

Example 1

(Production of pressure-sensitive adhesive composition for optical film)

2.5 parts by weight peryl TCP (B1) as a peroxide (B), 2.5 parts by weight as a cross-linking agent (C) other than peroxide, 100 parts by weight of a solid component of the (meth) (C1) and 0.1 part by weight of silane coupling agent (D) KBM-403 were mixed to prepare a solution (solid content 15% by weight) of the pressure-sensitive adhesive composition for an optical film.

(Formation of pressure-sensitive adhesive layer)

Next, the solution of the pressure-sensitive adhesive composition for an optical film was immersed in a solution of a polyethylene terephthalate (PET) film (product of Mitsubishi Chemical Corporation polyester film, no MRF38 oligomer-preventing layer) having a thickness of 38 mu m subjected to silicone treatment (exfoliation treatment) And dried at 120 DEG C for 2 minutes to form a pressure-sensitive adhesive layer.

(Production of optical member)

A polyvinyl alcohol film having a thickness of 20 占 퐉 was stretched to 3 times while dyeing in an iodine solution at a concentration of 0.3% at 30 占 폚 for one minute between rolls having different speed ratios. Thereafter, the film was stretched to a total draw ratio of 6 by immersing the film in an aqueous solution containing boric acid at a concentration of 4% at a concentration of 4% and potassium iodide at a concentration of 10% for 0.5 minutes. Next, the film was washed by immersing in an aqueous solution containing potassium iodide at a concentration of 1.5% at 30 DEG C for 10 seconds, and then dried at 50 DEG C for 4 minutes to obtain a polarizer. On one surface of the polarizer, a protective polarizing film (polarizing plate) having a total thickness of 27 占 퐉 was prepared by attaching an acrylic film (lactone denatured acrylic resin film) having a thickness of 20 占 퐉 as a protective film with a polyvinyl alcohol adhesive.

Corona treatment (corona discharge amount 80 [W · min / m ² ]) was performed on the polarizer side of the polarizing film to form the pressure sensitive adhesive layer to form an easy adhesion layer. Next, a PET film (subjected to silicone treatment) having a pressure-sensitive adhesive layer formed thereon was transferred to the side of the polarizer so that the easy-adhesion layer on the side of the polarizer was in contact with the pressure-sensitive adhesive layer to produce an optical member Respectively.

Examples 2 to 28 and Comparative Examples 1 to 9

Except that the kind, the content (content) and / or the temperature and time of the heat treatment at the time of forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive composition for optical film were changed as shown in Table 2 A pressure-sensitive adhesive composition for an optical film, a pressure-sensitive adhesive layer, and an optical member were prepared in the same manner as in Example 1.

Example (A) (B) (C) (D) (E) Drying temperature (캜) Drying time (min) Kinds Kinds content Kinds content content content One A1 B1 2.5 C1 0.1 0.1 - 110 2 2 A1 B1 5 C1 0.1 0.1 - 110 2 3 A1 B1 9 C1 0.1 0.1 - 110 2 4 A1 B1 / B2 1.5 / 1 C1 0.1 0.1 - 110 2 5 A1 B3 2.5 C1 0.1 0.1 - 110 2 6 A1 B4 2.5 C1 0.1 0.1 - 110 2 7 A1 B5 2.5 C1 0.1 0.1 - 110 2 8 A1 B6 2.5 C1 0.1 0.1 - 110 2 9 A1 B7 2.5 C1 0.1 0.1 - 130 2 10 A1 B1 2.5 C1 0.1 - 5 110 2 11 A1 B1 5 C1 0.1 - 5 110 2 12 A1 B1 2.5 C2 1.0 0.1 - 110 2 13 A1 B1 2.5 C1 0.1 - - 110 2 14 A2 B1 9 C1 0.1 - 5 110 2 15 A2 B1 2.5 C1 0.1 - 5 110 2 16 A2 B1 5 C1 0.1 - 5 110 2 17 A2 B1 9 C1 0.1 - 5 110 2 18 A3 B1 2.5 C1 0.1 - 5 110 2 19 A3 B1 5 C1 0.1 - 5 110 2 20 A3 B1 9 C1 0.1 - 5 110 2 21 A3 B1 / B2 1.5 / 1 C3 0.1 - 5 110 2 22 A3 B1 / B2 1.5 / 1 C4 0.1 - 5 110 2 23 A3 B1 / B2 1.5 / 1 C5 0.1 - 5 110 2 24 A3 B1 / B2 1.5 / 1 C6 0.1 - 5 110 2 25 A4 B1 2.5 C1 0.1 - 5 110 2 26 A4 B1 2.5 C1 0.1 0.1 5 110 2 27 A4 B1 5 C1 0.1 - 5 110 2 28 A4 B1 9 C1 0.1 - 5 110 2 Comparative Example (A) (B) (C) (D) (E) Drying temperature (캜) Drying time (min) Kinds Kinds content Kinds content content content One A1 - - C1 0.1 0.1 - 110 2 2 A1 B1 0.1 C1 0.1 0.1 - 110 2 3 A1 B1 0.3 C1 0.1 0.1 - 110 2 4 A1 B1 1.5 C1 0.1 0.1 - 110 2 5 A1 B1 2.5 C4 0.1 0.1 - 110 2 6 A1 B1 2.5 C1 2.5 0.1 - 110 2 7 A1 B1 2.5 C1 0.0005 0.1 - 110 2 8 A1 B8 0.3 C1 0.1 0.1 - 160 2 9 A1 B1 2.5 C1 0.1 0.1 - 110 2

Content: 100 parts by weight of (meth) acrylate copolymer (A)

Property evaluation method

<Durability>

The optical members prepared in the above Examples and Comparative Examples were cut into a 37-inch size and made into a sample, which was adhered to a non-alkali glass (Eagle XG, product of Corning Incorporated) having a thickness of 0.7 mm using a laminator. Then, the sample was autoclaved at 50 DEG C and 0.5 MPa for 15 minutes, and the sample was completely adhered to the non-acrylic glass. Samples in which these treatments were carried out were each provided with the following durability tests (1) to (3), and the appearance between the polarizing plate and the glass after each test was visually evaluated based on the following criteria.

(1) Treatment was conducted at 105 DEG C for 500 hours (heating test)

(2) The sample was treated for 500 hours in an atmosphere at 60 DEG C and 95% RH (relative humidity) (humidification test)

(3) The sample was allowed to stand in an environment of 85 캜 for 30 minutes, and then allowed to stand for 30 minutes in an environment of -40 캜 for one cycle and one cycle for one hour for 300 cycles (300 hours) (heat shock ).

Visual evaluation

⊚: No change in appearance such as foaming, peeling, no lifting.

○: There is a slight peeling or foaming at the end, but there is no practical problem.

?: There is peeling or foaming at the end, but there is no practical problem unless it is used for a special purpose.

X: Significant peeling at the end, causing a problem in practical use.

<Workability>

The optical member prepared in the above Examples and Comparative Examples was cut to a width of 25 mm and a length of 100 mm to give a sample 1, and a sample 2 (3 pieces produced by cutting 420 mm in length and 320 mm in width) was used. The sample 1 and the sample 2 were attached to a non-alkali glass plate (Eagle XG, product of Corning Incorporated) each having a thickness of 0.7 mm using a laminator, followed by autoclave treatment at 50 ° C and 5 atm for 15 minutes, . Thereafter, heat treatment was performed for 48 hours under drying conditions at 50 캜 (after heating).

The adhesive strength of the sample 1 was measured. The adhesive strength was measured according to JIS Z0237 (2009) at a peeling angle of 180 ° and a peeling speed of 300 mm / min under the conditions of 23 ° C and a relative humidity of 50% RH in a tensile tester (Tensilon Universal Material Testing Machine STA-1150 manufactured by Orientech) (N / 25 mm) at the time of removing the sample 1 in accordance with the method of testing the pressure-sensitive adhesive tape and the pressure-sensitive adhesive sheet of the pressure-sensitive adhesive sheet.

The sample 2 (3 pieces) was peeled off from the alkali-free glass plate by human hands, and the reworkability was evaluated based on the following criteria (actual reworkability).

evaluation

⊚: All three sheets can be peeled off without breaking the film or the film.

?: Some of the three films were broken but peeled off again by peeling.

?: All three films were broken but peeled off again by peeling.

X: The film was peeled off due to peeling of the film, or peeling of the film after peeling it several times.

<Gel fraction>

The pressure-sensitive adhesive layer produced by the methods described in the above-mentioned Examples and Comparative Examples was measured after being stored for 5 days under an environment of 23 ° C and 55% relative humidity (initial weight W1). Thereafter, the resultant was immersed in an ethyl acetate solution, allowed to stand at room temperature for one week, insoluble matter was removed, and the dried weight (W2) was measured. From the obtained value, the gel fraction was calculated according to the following formula (1).

[Formula 1]

Gel fraction (%) = (W2 / W1) x100

<Aging treatment>

If the gel fraction of the pressure-sensitive adhesive layer immediately after drying is in a certain region or more, there is no concern about scratches and durability, and there is no need for aging treatment (referred to as "aging treatment"). For this reason, based on the gel fraction of each sample measured by the above-described method, the following criteria were judged and the necessity of the aging treatment of each sample was evaluated.

?: Gel fraction 65% or more No influence on scratching, workability and durability; No aging treatment required.

?: Gel fraction 40% or more and less than 65% No influence on scratches; No aging treatment required.

X: Gel fraction less than 40% Scratches, worse in processability and durability deterioration; Requires aging treatment.

<Oligomer contamination>

A polyethylene terephthalate (PET) film (thickness 38 mu m, MRF38, manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd.) without the oligomer-preventing layer with the pressure-sensitive adhesive layer formed in each of the foregoing Examples and Comparative Examples was subjected to each of the tests The coating was applied to the coating line for 24 hours under the heat treatment temperature of Examples and Comparative Examples. Upon heating treatment while conveying each film sample, the precipitation of PET oligomer on the guide roll on the line was visually confirmed based on the following criteria.

○: No PET oligomer deposition on the guide roll.

?: A little amount of PET oligomer precipitation was present on the guide roll.

X: There is a large amount of PET oligomer precipitation on the guide roll.

<Pool shortage>

With respect to one (1 piece) of the polarizing plate with a pressure-sensitive adhesive layer prepared in each of the above-mentioned Examples and Comparative Examples, which was formed into a square having a length of 100 mm on one side with an automatic cutter NZ-600 manufactured by Ogino Precision Machinery Co., Was evaluated based on the following criteria.

O: The pool lack depth at the end is less than 100 占 퐉.

DELTA: The pool lack depth at the end is not less than 100 mu m and less than 300 mu m.

X: Pool lack depth at the end is 300 占 퐉 or more.

The evaluation results are shown in Table 3.

From the results shown in Table 3, the optical member manufactured using the pressure-sensitive adhesive composition for an optical film according to the present invention is excellent in durability even in a severe environment (high temperature, high humidity, heat shock (HS) test) It can be seen that the reheat property that can be easily peeled off is good. In addition, there is almost no possibility that the liquid crystal panel is stained, and when the optical member or the like is cut and used according to the application, it is found that the phenomenon in which the paste is inadequate at the end (the pull-in shortage) is largely suppressed and the pressure sensitive adhesive layer, It can be seen that the aging step is not necessary and therefore the handling property is excellent in terms of the manufacturing process.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (19)

(A2) a structural unit derived from a hydroxyl group-containing (meth) acrylate monomer and 0.01 to 5% by weight of a structural unit derived from an alkyl (meth) acrylate monomer, and (a3) A (meth) acrylate copolymer containing not more than 15% by weight of a constituent unit derived from a monomer other than the monomer constituting the units (a1) and (a2);
(B) a peroxide; And
(C) a crosslinking agent other than the peroxide (B).
The pressure-sensitive adhesive composition for optical films according to claim 1, wherein the pressure-sensitive adhesive composition for optical films comprises 100 parts by weight of the (meth) acrylate copolymer (A) 2 parts by weight or more and 10 parts by weight or less of the peroxide (B); And 0.001 to 2 parts by weight of the cross-linking agent (C).
The pressure-sensitive adhesive composition for an optical film according to claim 1, wherein the peroxide (B) has a one-minute half-life temperature of 80 to 125 ° C.
The optical film according to claim 1, wherein the pressure-sensitive adhesive composition for an optical film further comprises 0.01 to 1 part by weight of a silane coupling agent (D) based on 100 parts by weight of the (meth) acrylate copolymer (A) Sensitive adhesive composition.
The pressure-sensitive adhesive composition for an optical film according to claim 1, wherein the pressure-sensitive adhesive composition for an optical film further comprises (E) a silicate oligomer represented by the following formula (1)
[Chemical Formula 1]

R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a phenyl group, X ₁ and X ₂ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a phenyl group, , and n is an integer of 1 to 100.
The pressure-sensitive adhesive composition for an optical film according to claim 5, wherein the silicate oligomer (E) has a weight-average molecular weight of 300 to 30,000 g / mol.
The pressure-sensitive adhesive composition for optical films according to claim 1, wherein the crosslinking agent (C) comprises at least one of an isocyanate crosslinking agent, a carbodiimide crosslinking agent, an oxazoline crosslinking agent, an epoxy crosslinking agent and an aziridine crosslinking agent .
A pressure-sensitive adhesive layer for an optical film, which is formed from the pressure-sensitive adhesive composition for an optical film according to any one of claims 1 to 7.
A pressure-sensitive adhesive layer for an optical film according to claim 8; And
And a first optical film provided on one side of the pressure-sensitive adhesive layer for the optical film.
The optical member according to claim 9, wherein the adhesive layer for an optical film has a gel fraction of 40 to 95%.
The optical member according to claim 9, wherein the adhesive layer for an optical film has a gel fraction of 60 to 85%.
The optical member according to claim 9, wherein the optical member further comprises a glass or a second optical film on the side opposite to the side where the first optical film is provided on the pressure-sensitive adhesive layer.
The optical member according to claim 9, wherein the optical member further comprises at least one easy-adhesion treatment layer between the first optical film and the pressure-sensitive adhesive layer for the optical film.
The optical film according to claim 9, wherein the optical member includes a first adhesive layer and a second adhesive layer which are interposed between the first optical film and the adhesive layer for an optical film, Layer, and the pressure-sensitive adhesive layer for an optical film is adjacent to the second adhesive facilitating layer.
The optical member according to claim 9, wherein the first optical film is a polarizing plate.
The optical member according to claim 9, wherein the optical member satisfies the following formulas (1) and (2):
[Formula 1]
0.3? A ₀ ? 2.5
In the formula (1), A ₀ is an optical member attached to a glass plate, autoclaved at 50 ° C and 5 atm for 15 minutes to make a close contact, and then peeled at a peel angle of 180 ° and a peel rate of 300 mm / min, measured in accordance with JIS Z0237 (2009);
[Formula 2]
1.0? A? ₁ ? 3.9
In the formula (2), A ₁ denotes an optical member attached to a glass plate, autoclaved at 50 캜 for 5 minutes under a pressure of 5 atmospheric pressure, and then heated again at 50 캜 for 48 hours. % RH, a peel angle of 180 °, and a peel rate of 300 mm / min, measured in accordance with JIS Z0237 (2009).
An image display apparatus comprising at least one optical member according to claim 9.
A pressure-sensitive adhesive composition for an optical film according to any one of claims 1 to 7, which is applied onto a release sheet obtained by subjecting to a peeling treatment; And
A method for producing a pressure-sensitive adhesive layer for an optical film, which comprises a step of subjecting the applied pressure-sensitive adhesive composition for an optical film to a crosslinking reaction.
The method of producing a pressure-sensitive adhesive layer for an optical film according to claim 18, wherein the heat treatment temperature is 80 to 120 占 폚.