WO2011093261A1 - Adhesive optical film and image display device - Google Patents

Abstract

Provided is an adhesive optical film in which an adhesive layer is disposed on an optical film with an undercoat layer interposed therebetween. The adhesive layer is formed from an adhesive containing, as the base polymer, a block copolymer or graft copolymer comprising (meth)acrylic polymer (A) segments having a glass transition temperature of 0ºC or less and (meth)acrylic polymer (B) segments having a glass transition temperature of 40ºC or more. The undercoat layer contains polymers. The adhesive optical film has initial and long-term reworkability and durability.

Description

Adhesive optical film and image display device

The present invention relates to an adhesive optical film. Furthermore, the present invention relates to an image display device such as a liquid crystal display device, an organic EL display device, a CRT, or a PDP using the adhesive optical film. Examples of the optical film include a polarizing plate, a retardation plate, an optical compensation film, a brightness enhancement film, and those in which these are laminated.

In particular, when the optical film has a liquid crystal optical compensation layer, it is useful as an optical compensation film for improving display contrast and viewing angle characteristics of display colors, and a laminate of polarizers has an optical compensation function. It is useful as an elliptically polarizing plate. In particular, the liquid crystal optical compensation layer is useful in the case of a discotic liquid crystal layer in which a discotic liquid crystal compound is aligned.

In liquid crystal displays and the like, it is indispensable to dispose polarizing elements on both sides of the liquid crystal cell because of its image forming method, and generally polarizing plates are attached. In addition to polarizing plates, various optical elements have been used for liquid crystal panels in order to improve the display quality of displays. For example, a retardation plate for preventing coloring, a viewing angle widening film for improving the viewing angle of a liquid crystal display, and a brightness enhancement film for increasing the contrast of the display are used. These films are collectively called optical films.

When the optical film is attached to the liquid crystal cell, an adhesive is usually used. In addition, the adhesive between the optical film and the liquid crystal cell and the optical film is usually in close contact with each other using an adhesive to reduce the loss of light. In such a case, since the adhesive has the merit that a drying step is not required to fix the optical film, the adhesive is an adhesive optical film provided in advance as an adhesive layer on one side of the optical film. Generally used.

The required properties required for the pressure-sensitive adhesive include: (1) When an optical film is bonded to the surface of a liquid crystal panel, the optical film can be used even when the bonding position is wrong or a foreign object is caught in the bonding surface. Can be peeled off from the surface of the liquid crystal panel without any adhesive residue, and can be pasted (reworked) again. (2) There are problems caused by adhesives for durability tests such as heating and humidification that are normally performed as environmental promotion tests. It does not occur. Regarding reworkability, it is desirable that the optical film can be easily peeled from the liquid crystal cell or the like from the viewpoint of environmental measures such as recycling and disposal when the role of use as an image display device is finished. Therefore, with regard to reworkability, it is desirable that rework can be performed without problems even when recycling is performed after a long time has elapsed (for example, one year after production).

The pressure-sensitive adhesive optical film satisfying the reworkability and durability has a base polymer containing a functional group that reacts with an amino group via an anchor layer (undercoat layer) formed of a polyamine compound on the optical film. The thing which laminated | stacked the adhesive layer formed with the adhesive is proposed (patent document 1). In Patent Document 1, the pressure-sensitive adhesive in the pressure-sensitive adhesive layer and the polyamine compound in the anchor layer form a mixed reaction layer in the anchor layer, and the thickness of the mixed reaction layer is 50% or more of the total thickness of the anchor layer. The adhesion between the anchor layer and the pressure-sensitive adhesive layer is good. Therefore, in the pressure-sensitive adhesive optical film of Patent Document 1, reworkability immediately after the production of the pressure-sensitive adhesive optical film (initial) is good. However, even if it is the adhesive optical film of patent document 1, the rework property after a long time progress (for example, rework property after 1 year after manufacture) is not enough.

Further, as an adhesive for forming an adhesive layer of an adhesive optical film, A1-B-A2 (however, a methacrylic acid alkyl ester polymer (A) segment A1, A2 having a glass transition temperature of 100 ° C. or higher, and glass It has been proposed to use an adhesive that is not chemically crosslinked and contains an acrylic triblock copolymer composed of an acrylic acid alkyl ester polymer (B) segment) having a transition temperature of −20 ° C. or lower. (Patent Document 2). It is described that the pressure-sensitive adhesive optical film using the pressure-sensitive adhesive is excellent in the reworkability and durability. However, since the pressure-sensitive adhesive does not contain a cross-linking agent, the cross-linking step can be omitted, and the productivity is excellent. Therefore, the adhesiveness between the pressure-sensitive adhesive layer and the optical film is not sufficient, and the reworkability is It was bad from the beginning.

Japanese Patent No. 4007920 International Publication No. 2008/065982 Pamphlet

The present invention provides an adhesive optical film in which an optical film is provided with an adhesive layer, which can satisfy reworkability and durability at both the initial stage and after a long period of time. The purpose is to do.

Another object of the present invention is to provide an image display device using the adhesive optical film.

The present inventors have intensively studied to solve the above-mentioned problems. As a result, they have found that the above object can be achieved by the following adhesive optical film, and have completed the present invention.

That is, the present invention provides an optical film in which an adhesive layer is provided via an undercoat layer,
The pressure-sensitive adhesive layer has, as a base polymer, a (meth) acrylic polymer (A) segment having a glass transition temperature of 0 ° C. or lower and a (meth) acrylic polymer (B) segment having a glass transition temperature of 40 ° C. or higher. Formed of a pressure-sensitive adhesive containing a block copolymer or a graft copolymer, and
The undercoat layer relates to a pressure-sensitive adhesive optical film characterized by containing polymers.

In the pressure-sensitive adhesive optical film, the (meth) acrylic polymer (A) segment is 50% by weight or more of the total monomer unit of an acrylic acid alkyl ester, and the (meth) acrylic polymer (B) segment is the total monomer unit. It is preferable that 15% by weight or more of methacrylic acid alkyl ester.

In the pressure-sensitive adhesive optical film, the base polymer contained in the pressure-sensitive adhesive is a BAB triblock copolymer (where A is a (meth) acrylic polymer (A) segment, and B is a (meth) acrylic). The polymer (B) segment is preferred).

In the pressure-sensitive adhesive optical film, the polymer of the undercoat layer is preferably a polymer having a primary amino group at the terminal. The polymer having a primary amino group at the terminal is preferably a poly (meth) acrylic acid ester having a primary amino group at the terminal. Further, the primary amino group in the polymer having a primary amino group at the terminal is preferably derived from a polyethyleneimine-based material.

In the pressure-sensitive adhesive optical film, the undercoat layer preferably contains 0.01 to 500 parts by weight of an antioxidant with respect to 100 parts by weight of the polymers.

The antioxidant is preferably at least one selected from phenol-based, phosphorus-based, sulfur-based and amine-based antioxidants.

In the pressure-sensitive adhesive optical film, the optical film has a liquid crystal optical compensation layer on one side of the transparent base film, and the pressure-sensitive adhesive layer is provided on the liquid crystal optical compensation layer via an undercoat layer. Can be suitable. The liquid crystal optical compensation layer is suitable when it is a discotic liquid crystal layer. In addition, as the optical film, a film in which a polarizer is laminated on one side of the transparent base film on the side where the liquid crystal optical compensation layer is not formed can be suitably used.

The present invention also relates to an image display device characterized in that the adhesive optical film is used.

In the pressure-sensitive adhesive optical film of the present invention, as a pressure-sensitive adhesive used for the pressure-sensitive adhesive layer, a (meth) acrylic polymer (A) segment having a low glass transition temperature and a (meth) acrylic polymer having a high glass transition temperature ( B) A specific block copolymer or graft copolymer having a segment is used. The block copolymer or graft copolymer itself exhibits adhesiveness and cohesiveness required as an adhesive. Therefore, the block copolymer or graft copolymer does not need to be introduced with a functional group or used in combination with a crosslinking agent. On the other hand, the block copolymer or graft copolymer is an optical The adhesion to the film is poor and the reworkability is not satisfied.

In the pressure-sensitive adhesive optical film of the present invention, by providing a pressure-sensitive adhesive layer using the block copolymer or graft copolymer via an undercoat layer, a general functional group can be added to the formation of the pressure-sensitive adhesive layer. Reworkability is improved as compared with the case of using a cross-linked acrylic pressure-sensitive adhesive. In particular, reworkability after a long time (for example, reworkability after one year after production) is improved.

Usually, from the viewpoint of reworkability, an undercoat layer is provided in order to improve the adhesion between the pressure-sensitive adhesive layer and the optical film. The adhesion between the undercoat layer and the pressure-sensitive adhesive layer is disclosed in Patent Document 1. As described above, the reaction is performed by reacting the functional groups of both the undercoat layer and the pressure-sensitive adhesive layer. Therefore, when an adhesive layer is provided on the undercoat layer to improve adhesion, an adhesive having a functional group reactive with the functional group in the undercoat layer is preferably used for the adhesive layer. Surprisingly, in the present invention, when a block copolymer or graft copolymer is used in the pressure-sensitive adhesive layer, the block copolymer or graft copolymer is not chemically crosslinked, Even when the functional group having reactivity with the functional group of the undercoat layer is not present, the adhesiveness between the adhesive layer and the undercoat layer is improved by combining the pressure-sensitive adhesive layer and the undercoat layer. In particular, when a polymer having a primary amino group at the terminal is used for the undercoat layer, the adhesion between the optical film and the undercoat layer, the adhesion between the undercoat layer and the pressure-sensitive adhesive layer is improved, and the reworkability is improved. In the pressure-sensitive adhesive optical film of the present invention, the undercoat layer and the pressure-sensitive adhesive layer form a mixed layer. In the mixed layer, the polymers in the primer and the pressure-sensitive adhesive polymer in the pressure-sensitive adhesive layer (block copolymer or It is presumed that this is because physical cross-linking with the graft copolymer) is formed to express adhesion. In particular, when a poly (meth) acrylic acid ester having a primary amino group at the terminal is used for the undercoat layer among the polymers having a primary amino group at the terminal, methacryl Since a component having a high glass transition temperature such as methyl acid or methacrylic acid is contained, the glass transition temperature in the base polymer (block copolymer or graft copolymer) in the pressure-sensitive adhesive layer is 40 ° C. or more ( It is considered that physical cross-linking is formed by aggregation with the (meth) acrylic polymer (B) segment (segment exhibiting a high glass transition temperature). That is, the adhesive optical film of the present invention has significantly improved adhesion between the optical film and the adhesive layer, compared to the adhesive optical film using a cross-linked product of an acrylic polymer having a conventional functional group as the adhesive layer. In the adhesive optical film of the present invention, the adhesiveness between the pressure-sensitive adhesive layer and the undercoat layer is not due to chemical crosslinking of the functional group-containing component as in the conventional adhesive optical film. It is thought that crosslinks are formed.

It is sectional drawing of an example of the adhesive optical film of this invention. It is sectional drawing of an example of the adhesive optical film of this invention. It is sectional drawing of an example of the adhesive optical film of this invention.

Hereinafter, the present invention will be described with reference to the drawings. In the pressure-sensitive adhesive optical film of the present invention, for example, as shown in FIG. 1, a pressure-sensitive adhesive layer C is provided on one side of the optical film A via an undercoat layer B. In FIG. 1, the pressure-sensitive adhesive layer C is provided on one side of the optical film A via the undercoat layer B, but the same or different pressure-sensitive adhesive layer as the pressure-sensitive adhesive layer C is provided on the other side of the undercoat layer B. It can be provided with or without the same or different subbing layer.

In FIG. 2, the pressure-sensitive adhesive optical film of the present invention is a case where the optical film A has a liquid crystal optical compensation layer (for example, a discotic liquid crystal layer) A13 on one side of the transparent base film A11. An adhesive layer C is provided on the layer A13 with an undercoat layer B interposed therebetween. In FIG. 2, the case where the alignment film A12 is provided between the transparent base film A11 and the liquid crystal optical compensation layer A13 is illustrated, but instead of the alignment film A12, one side of the transparent base film A11 is rubbed. Can be used.

FIG. 3 shows the adhesive optical film of FIG. 2 in which a polarizer A14 and then a transparent protective film A15 are laminated on one side of the transparent substrate film A11 on the side where the liquid crystal optical compensation layer A13 is not formed. This is the case. In FIG. 3, the transparent substrate film A11 also serves as a transparent protective film for the polarizer A14.

Hereinafter, each configuration of the pressure-sensitive adhesive optical film of the present invention will be described in detail.

For the formation of the pressure-sensitive adhesive layer of the present invention, a (meth) acrylic polymer (A) segment having a glass transition temperature of 0 ° C. or lower and a (meth) acrylic polymer having a glass transition temperature of 40 ° C. or higher are used as a base polymer. (B) A pressure-sensitive adhesive containing a block copolymer having a segment or a graft copolymer is used.

In addition, the glass transition temperature of the (meth) acrylic polymer (A) segment is 0 ° C. or less, and imparts wettability to the adherend and flexibility as a pressure-sensitive adhesive at a normal use temperature. Adhesive strength is expressed in the pressure-sensitive adhesive layer. The glass transition temperature of the (meth) acrylic polymer (A) segment is preferably −20 ° C. or lower, more preferably −30 ° C. or lower. Usually, the glass transition temperature is −70 ° C. or higher. The glass transition temperature of the (meth) acrylic polymer (A) segment is preferably −20 ° C. or less from the viewpoint of excellent durability under low temperature conditions.

The glass transition temperature of the (meth) acrylic polymer (B) segment is 40 ° C. or higher, imparting cohesive force at normal use temperature, and having excellent adhesive properties and durability in the adhesive layer of the present invention. To express. The glass transition temperature of the (meth) acrylic polymer (B) segment is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and usually the glass transition temperature is 150 ° C. or lower. The glass transition temperature of the (meth) acrylic polymer (B) segment is preferably 80 ° C. or higher in view of excellent durability under high temperature conditions.

As the block copolymer or graft copolymer, those having the (meth) acrylic polymer (A) segment and the (meth) acrylic polymer (B) segment can be used. For example, when the (meth) acrylic polymer (A) segment is represented by A and the (meth) acrylic polymer (B) segment is represented by B, the block copolymer is represented by, for example, AB. A diblock copolymer; a triblock copolymer represented by ABA, BAB; a tetrablock copolymer, and a combination of A and B It can be illustrated. Examples of the graft copolymer include those having A or B as a main chain and a segment different from the main chain as a side chain. In addition, when there are two or more A and B, each A and B may be the same or different.

As the base polymer of the pressure-sensitive adhesive of the present invention, the block copolymer or graft copolymer can be used, but the block copolymer is preferable from the viewpoint of easy control of the glass transition temperature and the molecular weight, and the block copolymer. Among these, it is preferable to use a triblock copolymer represented by BAB, because it is easier to control the adhesive properties and bulk physical properties.

The block copolymer or graft copolymer has a weight average molecular weight of 50,000 to 300,000, preferably 60,000 to 250,000 from the viewpoint of both durability and reworkability. It is more preferably 70,000 to 230,000, and further preferably 70,000 to 200,000. When the molecular weight is smaller than 50,000, the cohesive force of the pressure-sensitive adhesive is insufficient, and the durability is inferior when an optical film is used while being bonded. Further, when the molecular weight is larger than 300,000, it takes time for the adherend to get wet with the pressure-sensitive adhesive, so that wetting progresses during storage of the product, the adhesive force increases, and rework becomes difficult. .

The molecular weight distribution (Mw / Mn) of the block copolymer or graft copolymer is 1.0 to 1.5, and from the viewpoint of high cohesion at high temperatures and excellent durability, 1.0 to 1.4. Preferably, it is 1.0 to 1.3.

Examples of the (meth) acrylic acid alkyl ester that is the main monomer unit of the (meth) acrylic polymer (A) segment include (meth) acrylic acid alkyl esters having an alkyl group with 1 to 18 carbon atoms. . The (meth) acrylic acid alkyl ester refers to an acrylic acid alkyl ester and / or a methacrylic acid alkyl ester, and (meth) in the present invention has the same meaning. Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, n (meth) acrylic acid -Hexyl, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, etc. Examples include (meth) acrylic acid alkyl esters. These can be used alone or in combination of two or more.

The (meth) acrylic polymer (A) segment contains (meth) acrylic acid alkyl ester as the main component of the monomer unit, containing 90% by weight or more, preferably 95% by weight or more of the total monomer unit, and having a glass transition temperature. The type and component composition of the monomer unit are not particularly limited as long as the temperature satisfies 0 ° C. or lower, but the (meth) acrylic polymer (A) segment preferably has an alkyl acrylate ester as the main monomer unit. . The (meth) acrylic polymer (A) segment has a glass transition temperature of 50% by weight or more, further 60% by weight or more, and more preferably 70% by weight or more of the total monomer units, which controls the glass transition temperature. This is preferable. Examples of the alkyl acrylate ester related to the main monomer unit in the (meth) acrylic polymer (A) segment include propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and n-acrylate in the above examples. An alkyl acrylate ester having 1 to 9 carbon atoms in the alkyl group such as octyl is preferable.

The weight ratio of the (meth) acrylic polymer (A) segment in the block copolymer or graft copolymer is preferably 50% to 95% from the viewpoint of obtaining stable adhesive strength and durability, and 60% More preferably, it is ˜85%. When the weight ratio of the (meth) acrylic polymer (A) segment is less than 50%, the adhesive force tends to be low. Further, when the weight ratio of the (meth) acrylic polymer (A) segment is more than 95%, the cohesive force is reduced because the proportion of the (meth) acrylic polymer (B) segment is small, and the optical film. When used as a pressure-sensitive adhesive, it is not preferable in terms of durability.

Examples of the (meth) acrylic acid alkyl ester that is the main monomer unit of the (meth) acrylic polymer (B) segment include (meth) acrylic acid alkyl esters having an alkyl group with 1 to 18 carbon atoms. . Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, n (meth) acrylic acid -Hexyl, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, ( Examples include (meth) acrylic acid alkyl esters such as (meth) acrylic acid isobornyl. These can be used alone or in combination of two or more.

The (meth) acrylic polymer (B) segment contains 90 wt% or more, preferably 95 wt% or more of the total monomer units, with (meth) acrylic acid alkyl ester as the main component of the monomer units, and has a glass transition temperature. As long as the temperature satisfies 40 ° C. or higher, the type and composition of the monomer units are not particularly limited, but 15% by weight or more, further 20% by weight or more, further 30% by weight or more of the total monomer units are alkyl methacrylate. An ester is preferred for controlling the glass transition temperature. Examples of the methacrylic acid alkyl ester relating to the main monomer unit in the (meth) acrylic polymer (B) segment include those having an alkyl group of 1 to 2 alkyl groups such as methyl methacrylate and ethyl methacrylate among the above examples. Methacrylic acid alkyl esters are preferred.

The weight ratio of the (meth) acrylic polymer (B) segment in the block copolymer or graft copolymer is a ratio other than the (meth) acrylic polymer (A) segment.

In the (meth) acrylic polymer (A) segment and (meth) acrylic polymer (B) segment, the (meth) acrylic acid is within the range of 10% by weight or less of the total monomer units of each segment. Other monomer units other than the alkyl ester may be included. Examples of the other monomer units include methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylic acid 2 -(Meth) acrylic acid ester having a functional group such as aminoethyl, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate; (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid Vinyl monomers having a carboxyl group such as; vinyl monomers having an amide group such as (meth) acrylamide; aromatic vinyl monomers such as styrene, α-methylstyrene and p-methylstyrene; conjugated dienes such as butadiene and isoprene -Based monomers: ethylene, propylene and other olefins System monomers; .epsilon.-caprolactone, lactone-based monomers such as valerolactone. These may be used alone or in combination of two or more.

The method for producing the block copolymer or graft copolymer includes the block copolymer or graft copolymer having the (meth) acrylic polymer (A) segment and the (meth) acrylic polymer (B) segment. As long as is obtained, a method according to a known method can be employed without any particular limitation. In general, as a method for obtaining a block copolymer having a narrow molecular weight distribution, a method of living polymerizing monomers as constituent units is employed. Examples of such living polymerization methods include a method of polymerizing using an organic rare earth metal complex as a polymerization initiator (JP-A-6-93060), an alkali metal or an alkaline earth metal using an organic alkali metal compound as a polymerization initiator. Anionic polymerization in the presence of a mineral salt such as a salt (see Japanese Patent Publication No. 7-25859), and anionic polymerization in the presence of an organoaluminum compound using an organic alkali metal compound as a polymerization initiator (Japanese Patent Laid-Open No. Hei 11- 335432), atom transfer radical polymerization method (ATRP) (Macromol. Chem. Phys. 201, 1108 to 1114 pages (2000)), etc. A method for obtaining a graft copolymer is disclosed in Japanese Patent No. 4228026. Examples include the method described in the specification and the like.

Among the above production methods, in the case of an anionic polymerization method using an organoaluminum compound as a catalyst, there is little deactivation during the polymerization, so there is little mixing of the deactivating component homopolymer. High transparency. Moreover, since the polymerization conversion rate of a monomer is high, there are few residual monomers in a product, and when using it as an adhesive for optical films, generation | occurrence | production of the bubble after bonding can be suppressed. Furthermore, the molecular structure of the (meth) acrylic polymer (B) segment block is highly syndiotactic and has an effect of enhancing durability when used in an adhesive for optical films. And because living polymerization is possible under relatively mild temperature conditions, it is possible to reduce the environmental burden (mainly the electric power applied to the refrigerator for controlling the polymerization temperature) for industrial production. There is.

Examples of the anionic polymerization method in the presence of the above organoaluminum compound include an organolithium compound and the following general formula (1):
AlR ¹ R ² R ³ (1)
Wherein R ¹ , R ² and R ³ are each independently an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, or an aryl which may have a substituent. Represents a group, an aralkyl group which may have a substituent, an alkoxyl group which may have a substituent, an aryloxy group which may have a substituent or an N, N-disubstituted amino group, or R ¹ represents any of the groups described above, and R ² and R ³ together represent an aryleneoxy group which may have a substituent. If necessary, in the reaction system, ethers such as dimethyl ether, dimethoxyethane, diethoxyethane, 12-crown-4; triethylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ', N'','' -Pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, pyridine, 2,2′-dipyridyl and other nitrogen-containing compounds are further used to form (meth) acrylic acid ester A polymerization method or the like can be employed.

Examples of the organic lithium compound include methyl lithium, ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, isobutyl lithium, tert-butyl lithium, n-pentyl lithium, and n-hexyl lithium. Alkyllithium and alkyldilithium such as tetramethylenedilithium, pentamethylenedilithium and hexamethylenedilithium; aryllithium and aryldi such as phenyllithium, m-tolyllithium, p-tolyllithium, xylyllithium and lithium naphthalene Lithium; benzyl lithium, diphenylmethyl lithium, trityl lithium, 1,1-diphenyl-3-methylpentyl lithium, α-methylstyryl lithium, diisopropeni Aralkyllithium and aralkyldilithium such as dilithium produced by the reaction of benzene and butyllithium; lithium amides such as lithium dimethylamide, lithium diethylamide and lithium diisopropylamide; methoxylithium, ethoxylithium, n-propoxylithium, isopropoxylithium, n -Butoxylithium, sec-butoxylithium, tert-butoxylithium, pentyloxylithium, hexyloxylithium, heptyloxylithium, octyloxylithium, phenoxylithium, 4-methylphenoxylithium, benzyloxylithium, 4-methylbenzyloxylithium, etc. Lithium alkoxide of the following. These may be used alone or in combination of two or more.

Examples of the organoaluminum compound represented by the above general formula include trimethylaluminum, triethylaluminum, tri-n-butylaluminum, tris-butylaluminum, tri-t-butylaluminum, triisobutylaluminum, and tri-n-hexylaluminum. , Tri-n-octylaluminum, tri-2-ethylhexylaluminum, trialkylaluminum such as triphenylaluminum, dimethyl (2,6-di-tert-butyl-4-methylphenoxy) aluminum, dimethyl (2,6-di-tert -Butylphenoxy) aluminum, diethyl (2,6-di-tert-butyl-4-methylphenoxy) aluminum, diethyl (2,6-di-tert-butylphenoxy) aluminum, diisobutene Ru (2,6-di-tert-butyl-4-methylphenoxy) aluminum, diisobutyl (2,6-di-tert-butylphenoxy) aluminum, di-n-octyl (2,6-di-tert-butyl- 4-methylphenoxy) aluminum, dialkylphenoxyaluminum such as di-n-octyl (2,6-di-tert-butylphenoxy) aluminum, methylbis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, Methylbis (2,6-di-tert-butylphenoxy) aluminum, ethyl [2,2′-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum, ethylbis (2,6-di-tert-butyl-) 4-Merphenoxy) aluminum, ethylbis (2,6-di) tert-butylphenoxy) aluminum, ethyl [2,2′-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum, isobutylbis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, Isobutylbis (2,6-di-tert-butylphenoxy) aluminum, isobutyl [2,2′-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum, n-octylbis (2,6-di-tert) -Butyl-4-methylphenoxy) aluminum, n-octylbis (2,6-di-tert-butylphenoxy) aluminum, n-octyl [2,2'-methylenebis (4-methyl-6-tert-butylphenoxy)] Alkyl diphenoxy aluminum such as aluminum , Methoxybis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, methoxybis (2,6-di-tert-butylphenoxy) aluminum, methoxy [2,2′-methylenebis (4-methyl-6) -Tert-butylphenoxy)] aluminum, ethoxybis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, ethoxybis (2,6-di-tert-butylphenoxy) aluminum, ethoxy [2,2'- Methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum, isopropoxybis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, isopropoxybis (2,6-di-tert-butyl) Phenoxy) aluminum, isopropoxy [ , 2′-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum, tert-butoxybis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, tert-butoxybis (2,6-di) -Tert-butylphenoxy) aluminum, tert-butoxy [2,2′-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum and other alkoxydiphenoxyaluminums, tris (2,6-di-tert-butyl) Examples include triphenoxyaluminum such as -4-methylphenoxy) aluminum and tris (2,6-diphenylphenoxy) aluminum. Among these organoaluminum compounds, isobutylbis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, isobutylbis (2,6-di-tert-butylphenoxy) aluminum, isobutyl [2,2 ′ -Methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum and the like are easy to handle, and the polymerization of the acrylate ester can proceed without deactivation under relatively mild temperature conditions. Is particularly preferable. These may be used alone or in combination of two or more.

In addition to the block copolymer or graft copolymer, the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer of the present invention includes, if necessary, a crosslinking agent such as an isocyanate compound, a tackifier, a plasticizer, and glass. Fillers, pigments, colorants, fillers, antioxidants, ultraviolet absorbers, silane coupling agents, and the like made of fibers, glass beads, metal powders, other inorganic powders, etc., and within the scope of the present invention Various additives can be used as appropriate. Moreover, it is good also as an adhesive layer etc. which contain microparticles | fine-particles and show light diffusibility.

The undercoat layer is formed of an undercoat containing polymers and an antioxidant. It is desirable that the polymer material is a material that exhibits good adhesion to both the pressure-sensitive adhesive layer and the optical film (for example, a liquid crystal optical compensation layer) and forms a film having excellent cohesive strength.

Examples of the polymers include polyurethane resins, polyester resins, and polymers containing amino groups in the molecule. The polymer may be used in any of a solvent-soluble type, a water-dispersed type, and a water-soluble type. For example, water-soluble polyurethane, water-soluble polyester, water-soluble polyamide and the like and water-dispersible resins (ethylene-vinyl acetate emulsion, (meth) acrylic emulsion, etc.) can be mentioned. The water-dispersed type is obtained by emulsifying various resins such as polyurethane, polyester and polyamide using an emulsifier, or by introducing an anionic group, a cationic group or a nonionic group of a water-dispersible hydrophilic group into the resin. The self-emulsified product can be used. Moreover, an ionic polymer complex can be used.

For example, when the pressure-sensitive adhesive layer contains an isocyanate compound, the polymer preferably has a functional group having reactivity with the isocyanate compound. As the polymers, polymers containing an amino group in the molecule are preferable. In particular, those having a primary amino group at the terminal are preferably used, and the reaction with the isocyanate compound improves the durability by adhesion more firmly. The polymer having a primary amino group at the terminal is preferably a poly (meth) acrylic acid ester having a primary amino group at the terminal.

Examples of polymers containing amino groups in the molecule include polymers of amino group-containing monomers such as polyethyleneimine, polyallylamine, polyvinylamine, polyvinylpyridine, polyvinylpyrrolidine, dimethylaminoethyl acrylate, etc. Can do. Among these, polyethyleneimine type is preferable. Any polyethyleneimine-based material may be used as long as it has a polyethyleneimine structure. Examples thereof include polyethyleneimine, an ethyleneimine adduct and / or a polyethyleneimine adduct to a polyacrylic acid ester. In particular, an ethyleneimine adduct and / or a polyethyleneimine adduct to a polyacrylic acid ester, which is a poly (meth) acrylic acid ester having a primary amino group at a terminal, is preferable.

Polyethyleneimine is not particularly limited, and various types can be used. The weight average molecular weight of polyethyleneimine is not particularly limited, but is usually about 1 to 1,000,000. Examples of commercially available polyethyleneimine products include Epomin SP series (SP-003, SP006, SP012, SP018, SP103, SP110, SP200, etc.) and Epomin P-1000 manufactured by Nippon Shokubai Co., Ltd. Of these, Epomin P-1000 is preferred.

The polyacrylic acid ester of an ethyleneimine adduct and / or a polyethyleneimine adduct to a polyacrylic acid ester is an alkyl (meth) acrylate that constitutes a base polymer (acrylic polymer) of an acrylic pressure-sensitive adhesive described later and a copolymer thereof. It can be obtained by emulsion polymerization of monomers according to a conventional method. As the copolymerization monomer, a monomer having a functional group such as a carboxyl group for reacting ethyleneimine or the like is used. The proportion of the monomer having a functional group such as a carboxyl group is appropriately adjusted depending on the proportion of ethyleneimine to be reacted. Further, as the copolymerization monomer, it is preferable to use a styrene monomer. Moreover, it can also be set as the addition product which grafted polyethyleneimine by making the polyethyleneimine separately synthesize | combined react with the carboxyl group etc. in acrylic ester. For example, an example of a commercially available product is Poliment NK-380 manufactured by Nippon Shokubai Co., Ltd.

Also, an ethyleneimine adduct and / or a polyethyleneimine adduct of an acrylic polymer emulsion can be used. For example, as an example of a commercially available product, POLYMENT SK-1000 manufactured by Nippon Shokubai Co., Ltd. can be mentioned.

In addition to the above, as a polymer having a primary amino group at the terminal, a carboxyl group or a hydroxyl group in the polyacrylate ester is reacted with an excess diisocyanate, and further reacted with an excess diamine to form a primary amino group at the terminal. What has been introduced. The poly (meth) acrylic acid ester having a primary amino group at the terminal can be obtained by copolymerizing the (meth) acrylic acid ester and a monomer having a primary amino group at the terminal. Examples of the monomer having a primary amino group at the terminal include aminoethyl (meth) acrylate and aminopropyl (meth) acrylate.

In addition to the above-mentioned polymers, various additives such as antioxidants can be appropriately used in the undercoat layer as necessary and within a range not departing from the object of the present invention.

Examples of the antioxidant contained in the undercoat layer include phenol-based, phosphorus-based, sulfur-based and amine-based antioxidants, and at least one selected from these is used. Among these, a phenolic antioxidant is preferable.

Specific examples of the phenolic antioxidant include 2,6-di-t-butyl-p-cresol, 2,6-di-t-butyl-4-ethylphenol, 2,6- Dicyclohexyl-4-methylphenol, 2,6-diisopropyl-4-ethylphenol, 2,6-di-t-amyl-4-methylphenol, 2,6-di-t-octyl-4-n-propylphenol, 2,6-dicyclohexyl-4-n-octylphenol, 2-isopropyl-4-methyl-6-t-butylphenol, 2-t-butyl-4-ethyl-6-t-octylphenol, 2-isobutyl-4-ethyl- 6-t-hexylphenol, 2-cyclohexyl-4-n-butyl-6-isopropylphenol, styrenated mixed cresol, DL α-tocopherol, stearyl β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, etc. as a bicyclic phenol compound, 2,2′-methylenebis (4-methyl-6-t-butylphenol) 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-thiobis (4-methyl-6- t-butylphenol), 4,4'-methylenebis (2,6-di-t-butylphenol), 2,2'-methylenebis [6- (1-methylcyclohexyl) -p-cresol], 2,2'-ethylidene Bis (4,6-di-t-butylphenol), 2,2′-butylidenebis (2-t-butyl-4-methylphenol), 3,6-dioxaoctame Tylene bis [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate], triethylene glycol bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1 , 6-hexanediol bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2′-thiodiethylenebis [3- (3,5-di-t-butyl- 4-hydroxyphenyl) propionate] and the like as 1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-tris (2 , 6-Dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3,5-tris [(3,5-di-tert-butyl-4-hydroxy Phenyl) propionyloxyethyl] isocyanurate, tris (4-tert-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate, 1,3,5-trimethyl-2,4,6-tris (3,5 -Di-t-butyl-4-hydroxybenzyl) benzene or the like as a tetracyclic phenol compound, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane or the like, Phosphorus-containing phenol compounds such as bis (3,5-di-t-butyl-4-hydroxybenzylphosphonate ethyl) calcium, bis (3,5-di-t-butyl-4-hydroxybenzylphosphonate ethyl) nickel, etc. Can be mentioned.

Specific examples of phosphorus antioxidants include trioctyl phosphite, trilauryl phosphite, tristridecyl phosphite, trisisodecyl phosphite, phenyl diisooctyl phosphite, phenyl diisodecyl phosphite, phenyl di (tridecyl) phos Phyto, diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyltridecyl phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (Butoxyethyl) phosphite, tetratridecyl-4,4'-butylidenebis (3-methyl-6-tert-butylphenol) -diphosphite, 4,4'-isopropylidene-diphenol alkylphos Phyto (however, alkyl has about 12 to 15 carbon atoms), 4,4'-isopropylidenebis (2-t-butylphenol) di (nonylphenyl) phosphite, tris (biphenyl) phosphite, tetra (tridecyl)- 1,1,3-tris (2-methyl-5-tert-butyl-4-hydroxyphenyl) butane diphosphite, tris (3,5-di-tert-butyl-4-hydroxyphenyl) phosphite, hydrogenation -4,4'-isopropylidene diphenol polyphosphite, bis (octylphenyl) bis [4,4'-butylidene bis (3-methyl-6-t-butylphenol)] 1,6-hexanediol diphosphite Hexatridecyl-1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenol) diphos Ite, tris [4,4'-isopropylidenebis (2-tert-butylphenol)] phosphite, tris (1,3-distearoyloxyisopropyl) phosphite, 9,10-dihydro-9-phosphaphenanthrene -10-oxide, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylenediphosphonite, distearyl pentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, phenyl 4,4'-isopropylidenediphenol pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methyl) Phenyl) pentaerythritol diphosphite and phenylbis Such as phenol -A- pentaerythritol diphosphite, and the like.

As the sulfur-based antioxidant, dialkylthiodipropionate and polyhydric alcohol ester of alkylthiopropionic acid are preferably used. The dialkylthiodipropionate used here is preferably a dialkylthiodipropionate having an alkyl group having 6 to 20 carbon atoms, and the polyhydric alcohol ester of alkylthiopropionic acid is an alkyl having 4 to 20 carbon atoms. Polyalkyl alcohol esters of alkylthiopropionic acid having a group are preferred. In this case, examples of the polyhydric alcohol constituting the polyhydric alcohol ester include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and trishydroxyethyl isocyanurate. Examples of such dialkylthiodipropionate include dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate. On the other hand, as the polyhydric alcohol ester of alkylthiopropionic acid, for example, glycerin tributylthiopropionate, glycerin trioctylthiopropionate, glycerin trilauryl thiopropionate, glycerin tristearyl thiopropionate, trimethylol ethane tributyl Thiopropionate, trimethylol ethane trioctyl thiopropionate, trimethylol ethane trilauryl thiopropionate, trimethylol ethane tristearyl thiopropionate, pentaerythritol tetrabutyl thiopropionate, pentaerythritol tetraoctyl thiopro Pionate, pentaerythritol tetralauryl thiopropionate, pentaerythritol tetrastearyl thiopropionate, etc. It can be mentioned.

Specific examples of the amine antioxidant include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2 , 6,6-tetramethylpiperidineethanol polycondensate, N, N ′, N ″, N ″ ″-tetrakis- (4,6-bis- (butyl- (N-methyl-2,2,6 , 6-Tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine, dibutylamine, 1,3,5-triazine, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine polycondensate, poly [ {6- (1,1,3,3- Tramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6 -Tetramethyl-4-piperidyl) imino}], tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, 2,2,6,6 -Tetramethyl-4-piperidylbenzoate, bis- (1,2,6,6-pentamethyl-4-pepyridyl) -2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n- Butyl malonate, bis- (N-methyl-2,2,6,6-tetramethyl-4-piperidyl) sebacate, 1,1 '-(1,2-ethanediyl) bis (3,3,5,5- Tetramethylpiperazinone), ( Mixed 2,2,6,6-tetramethyl-4-piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate, (mixed 1,2,2,6,6-pentamethyl-4- Piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate, mixed [2,2,6,6-tetramethyl-4-piperidyl / β, β, β ′, β′-tetramethyl-3 , 9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethyl] -1,2,3,4-butanetetracarboxylate, mixed [1,2,2,6,6 -Pentamethyl-4-piperidyl / β, β, β ', β'-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethyl] -1,2, 3,4-butanetetracarboxylate N, N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro -1,3,5-triazine condensate, poly [6-N-morpholyl-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) Imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imide], N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine and Condensate with 1,2-dibromoethane, [N- (2,2,6,6-tetramethyl-4-piperidyl) -2-methyl-2- (2,2,6,6-tetramethyl-4 -Piperidyl) imino] propionamide Can.

When the undercoat layer contains a polymer and an antioxidant, it usually contains 0.01 to 500 parts by weight of the antioxidant with respect to 100 parts by weight of the polymers. When the proportion of the antioxidant used is less than 0.01 parts by weight, the effect as an antioxidant cannot be expected. On the other hand, if it exceeds 500 parts by weight, it is not preferable in terms of anchoring properties and appearance. The use ratio of the antioxidant is preferably 0.1 to 300 parts by weight, more preferably 1 to 100 parts by weight, when emphasis is placed on anchoring properties and appearance.

In forming the undercoat layer, a crosslinking agent can be contained in addition to the polymers. For example, the compound which reacts with the polymer containing an amino group can be mixed and cross-linked to improve the strength of the undercoat layer. Examples of the compound that reacts with the polymer containing an amino group include an epoxy compound.

The production of the pressure-sensitive adhesive optical film of the present invention is performed, for example, by forming an undercoat layer on an optical film (for example, a liquid crystal optical compensation layer) and further forming a pressure-sensitive adhesive layer.

The undercoat layer is formed, for example, by applying and drying a solution of the undercoat containing the polymers and the antioxidant using a coating method such as a coating method, a dipping method, or a spray method to form an undercoat layer. . The thickness of the undercoat layer is preferably about 10 to 5000 nm, more preferably in the range of 50 to 500 nm. When the thickness of the undercoat layer is reduced, it does not have bulk properties, does not exhibit sufficient strength, and sufficient adhesion may not be obtained. Moreover, when too thick, there exists a possibility of causing the fall of an optical characteristic. The application amount (solid content) of the undercoat layer is preferably 0.1 to 5 cubic centimeters per square meter. Further, it is preferably 0.1 to 1 cubic centimeter, more preferably 0.1 to 0.5 cubic centimeter.

The pressure-sensitive adhesive layer is formed by laminating on the undercoat layer. The forming method is not particularly limited, and examples thereof include a method of applying and drying an adhesive (solution), a method of transferring with a release sheet provided with an adhesive layer, and the like. As a coating method, a roll coating method such as reverse coating or gravure coating, a spin coating method, a screen coating method, a fountain coating method, a dipping method, or a spray method can be adopted.

As a constituent material of the release sheet, paper, polyethylene, polypropylene, polyethylene terephthalate and other synthetic resin films, rubber sheets, paper, cloth, non-woven fabric, nets, foam sheets and metal foils, and appropriate thin leaf bodies such as laminates thereof Etc. In order to improve the peelability from the pressure-sensitive adhesive layer, the surface of the release sheet 4 may be subjected to a peeling treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment as necessary.

In the adhesive optical film, an antistatic agent can be used in order to impart antistatic properties. The antistatic agent can be contained in each layer, and an antistatic layer can be separately formed. Antistatic agents include ionic surfactant systems; conductive polymer systems such as polyaniline, polythiophene, polypyrrole, and polyquinoxaline; metal oxide systems such as tin oxide, antimony oxide, and indium oxide. From the viewpoint of appearance, antistatic effect, and stability of the antistatic effect when heated and humidified, a conductive polymer system is preferably used. Among these, water-soluble conductive polymers such as polyaniline and polythiophene or water-dispersible conductive polymers are particularly preferably used. This is preferable in the case where a water-soluble conductive polymer or a water-dispersible conductive polymer is used as a material for forming the antistatic layer from the viewpoint of suppressing deterioration of the optical film substrate due to an organic solvent during the coating process.

Examples of the optical film include various types. Examples of the optical film include a polarizing plate, a retardation plate, an optical compensation film, a brightness enhancement film, and those in which these are laminated.

As the optical film of the present invention, for example, as shown in FIG. 2, the optical film A has a liquid crystal optical compensation layer (for example, discotic liquid crystal layer) A13 on one side of the transparent base film A11. .

As the transparent substrate film, various transparent materials can be used. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin) And polymers based on polycarbonate and polycarbonate. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Polymer blends and the like can also be cited as examples of polymers forming the transparent substrate film.

Further, a polymer film described in JP-A-2001-343529 (WO01 / 37007), for example, (A) a thermoplastic resin having a substituted and / or unsubstituted imide group in the side chain, and (B) a substitution in the side chain. And / or a resin composition containing an unsubstituted phenyl and a thermoplastic resin having a nitrile group. Specific examples include a film of a resin composition containing an alternating copolymer composed of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a film made of a mixed extruded product of the resin composition or the like can be used.

The thickness of the transparent substrate film can be appropriately determined, but is generally about 1 to 500 μm from the viewpoints of workability such as strength and handleability, and thin film properties. In particular, 5 to 200 μm is preferable.

Further, it is preferable that the transparent base film is as colored as possible. Therefore, Rth = (nx−nz) · d (where nx is the refractive index in the slow axis direction in the film plane, nz is the refractive index in the film thickness direction, and d is the film thickness). A protective film having a direction retardation of −90 nm to +75 nm is preferably used. By using a film having such a thickness direction retardation value (Rth) of −90 nm to +75 nm, the coloring (optical coloring) of the polarizing plate caused by the transparent substrate film can be almost eliminated. The thickness direction retardation (Rth) is more preferably −80 nm to +60 nm, and particularly preferably −70 nm to +45 nm.

The transparent base film is preferably a cellulose polymer such as triacetyl cellulose or a norbornene polymer from the viewpoint of polarization characteristics and durability. Cellulose polymers such as triacetyl cellulose are particularly preferable.

For forming the liquid crystal optical compensation layer, for example, a polymerizable liquid crystal monomer and / or a liquid crystal polymer are used. These polymerizable liquid crystal monomers and / or liquid crystal polymers can form a liquid crystal optical compensation layer by being oriented and cured (solidified) after coating on a transparent substrate film. When the polymerizable liquid crystal monomer is used, a photopolymerization initiator is usually used. Various photopolymerization initiators can be used without particular limitation.

The optical compensation layer includes a discotic liquid crystal layer. The discotic liquid crystal layer is formed by alignment and curing of a discotic liquid crystal compound having a polymerizable unsaturated group. The discotic liquid crystal layer is useful as an optical compensation layer, and can improve the viewing angle, contrast, brightness, and the like. The discotic liquid crystal compound has a polymerizable unsaturated group, and the discotic liquid crystal layer is formed by aligning and curing the compound. The discotic liquid crystal layer is preferably one in which a discotic liquid crystal compound is tilted. The thickness of the discotic liquid crystal layer is usually about 0.5 to 10 μm.

The discotic liquid crystal compound has negative refractive index anisotropy (uniaxiality). Destrade et al., Mol. Cryst. 71, 111 (1981), benzene derivatives and B.I. Kohne et al., Angew. Chem. 96, page 70 (1984) and the cyclohexane derivatives described in J. Am. M.M. Lehn et al. Chem. Commun. , 1794 (1985), J. Am. Zhang et al., J. Am. Chem. Soc. 116, 2655 (1994), such as azacrown and phenylacetylene macrocycles, etc., which are generally used as a mother nucleus at the center of a molecule, and are a linear alkyl group or alkoxy group, substituted A structure in which a benzoyloxy group or the like is radially substituted as a straight chain thereof exhibits liquid crystallinity and includes what is generally called a discotic liquid crystal. However, the molecule itself is not limited to the above description as long as the molecule itself has negative uniaxiality and can give a certain orientation. In the present invention, the discotic liquid crystal compound has a polymerizable unsaturated group (for example, acryloyl group, methacryloyl group, vinyl group, allyl group, etc.) that undergoes a curing reaction with heat, light, or the like. Note that the discotic liquid crystal layer does not necessarily need to be a final product, and includes a liquid crystal layer that has been polymerized or cross-linked by the reaction of a polymerizable unsaturated group to increase the molecular weight and lose liquid crystallinity.

In addition, discotic liquid crystal compounds are optical molecules such as reaction products of discotic liquid crystals that no longer exhibit liquid crystallinity due to reactions with various discotic liquid crystal compounds and other low molecular compounds and polymers. In general, it means all compounds having negative uniaxiality.

For the alignment treatment of the discotic liquid crystal, the surface of the transparent substrate film is rubbed or an alignment film is used. Examples of the alignment film include an inorganic oblique deposition film or an alignment film obtained by rubbing a specific organic polymer film. There is a thin film in which isomerization is caused by light, such as an LB film made of an azobenzene derivative, and molecules are uniformly arranged with directionality. Examples of the organic alignment film include polyimide films and organic polymer films that form a hydrophobic surface such as alkyl chain-modified poval, polyvinyl butyral, and polymethyl methacrylate. In addition, an SiO oblique deposition film may be used as the inorganic oblique deposition film.

The discotic liquid crystal compound is tilted and aligned. For example, a discotic liquid crystal compound (polymerizable liquid crystal compound) is applied to form a tilted alignment state by forming an alignment film on a transparent substrate film. Thereafter, a method such as fixing by irradiation with light such as ultraviolet light or heat can be used. It is also possible to form the discotic liquid crystal on another alignment substrate by tilting and then transferring it onto a transparent support using an optically transparent adhesive or pressure sensitive adhesive. is there.

As such a discotic liquid crystal layer, those described in JP-A-8-95032 and Japanese Patent No. 2767382 are preferably used. A wide-view film manufactured by Fuji Photo Film Co., Ltd. is one in which such a discotic liquid crystal inclined alignment layer is formed on a cellulosic polymer film.

The liquid crystal optical compensation layer other than the above can be formed of, for example, a nematic liquid crystalline monomer and / or polymer.

In the optical film of the present invention, as shown in FIG. 3, a polarizer A14 and then a transparent protective film A15 are laminated on one side of the transparent base film A11 on the side where the liquid crystal optical compensation layer A13 is not formed. Things can be used.

The polarizer A14 is bonded to the transparent base film A11 using an adhesive. In FIG. 3, the transparent base film A11 also serves as a transparent protective film for the polarizer A14. However, the transparent base film A11 is provided with a polarizing plate having a transparent protective film on one or both sides of the polarizer. It can also be laminated.

The polarizer is not particularly limited, and various types can be used. Examples of polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. Examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.

A polarizer obtained by uniaxially stretching a polyvinyl alcohol film dyed with iodine can be prepared by, for example, dying polyvinyl alcohol in an aqueous iodine solution and stretching it 3 to 7 times the original length. If necessary, it can be immersed in an aqueous solution such as potassium iodide which may contain boric acid, zinc sulfate, zinc chloride or the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with dirt and anti-blocking agents by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven coloring by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched even in an aqueous solution such as boric acid or potassium iodide or in a water bath.

The material forming the transparent protective film provided on one or both sides of the polarizer is preferably a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like. The transparent protective film can use the same material as the transparent substrate film. The same applies to the thickness.

The transparent base film and the transparent protective film may use the same polymer material or different polymer materials.

The polarizer, the transparent substrate film, and the transparent protective film are usually in close contact with each other through an aqueous adhesive or the like. Examples of the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, a water-based polyurethane, and a water-based polyester. In addition, in bonding of a polarizer, a transparent base film, and a transparent protective film, an activation process can be performed to a transparent base film and a transparent protective film. Various methods can be employed for the activation treatment, for example, saponification treatment, corona treatment, low-pressure UV treatment, plasma treatment, or the like. The activation treatment is effective particularly when the transparent substrate film is triacetyl cellulose, norbornene resin, polycarbonate, polyolefin resin, or the like.

The surface of the transparent protective film to which the polarizer is not bonded may be subjected to a treatment for the purpose of hard coat layer, antireflection treatment, sticking prevention, diffusion or antiglare.

In addition to the optical film in which the polarizing plate is laminated, as an optical film used for the pressure-sensitive adhesive optical film of the present invention, an optical layer used for forming an image display device such as a liquid crystal display device may be laminated. it can. For example, an optical layer that may be used for forming a liquid crystal display device such as a reflection plate, an anti-transmission plate, a retardation plate (including wavelength plates such as 1/2 and 1/4), and a brightness enhancement film. Can be mentioned. These can be used alone as an optical film, or can be laminated on the polarizing plate for practical use and used as one layer or two or more layers.

An optical film in which the optical layer is laminated on a polarizing plate can be formed by a method of sequentially laminating separately in the manufacturing process of a liquid crystal display device or the like. There is an advantage that the manufacturing process of a liquid crystal display device or the like can be improved because of excellent stability and assembly work. For the lamination, an appropriate adhesive means such as an adhesive layer can be used. When adhering the polarizing plate and the other optical layer, their optical axes can be set at an appropriate arrangement angle in accordance with the target phase difference characteristic.

The pressure-sensitive adhesive optical film of the present invention can be preferably used for forming various image display devices such as a liquid crystal display device. The liquid crystal display device can be formed according to the conventional method. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, an adhesive optical film, and an illumination system as necessary, and incorporating a drive circuit. There is no particular limitation except that an adhesive optical film is used. As the liquid crystal cell, any type such as a TN type, an STN type, or a π type can be used.

Appropriate liquid crystal display devices such as a liquid crystal display device in which an adhesive optical film is disposed on one side or both sides of a liquid crystal cell, and a backlight or reflector used in an illumination system can be formed. In that case, the optical film according to the present invention can be installed on one side or both sides of the liquid crystal cell. When optical films are provided on both sides, they may be the same or different. Further, when forming a liquid crystal display device, for example, a single layer or a suitable part such as a diffusion plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusion plate, a backlight, Two or more layers can be arranged.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In addition, all the parts and% in each example are based on weight.

The block copolymer or graft copolymer used in Examples and Comparative Examples was obtained by the following production examples using chemicals dried and purified by a conventional method. At that time, the molecular weight, molecular weight distribution, composition, glass transition temperature of each block, and polymerization conversion rate of the obtained block copolymer and graft copolymer were analyzed by the following methods.

(1) Measurement of number average molecular weight (Mn), weight average molecular weight (Mw), molecular weight distribution (Mw / Mn) by gel permeation chromatography (GPC):
Apparatus: Gel permeation chromatograph manufactured by Tosoh Corporation (HLC-8020)
Column: TSKgel GMHXL, G4000HXL and G5000HXL manufactured by Tosoh Corporation are connected in series. Eluent: Tetrahydrofuran eluent Flow rate: 1.0 ml / min Column temperature: 40 ° C.
Detection method: differential refractive index (RI)
Calibration curve: Created using standard polystyrene

(2) Measurement of the content of each copolymer component in the copolymer by proton nuclear magnetic resonance (1H-NMR) spectroscopy:
Apparatus: JEOL nuclear magnetic resonance apparatus (JNM-LA400)
Solvent: deuterated chloroform In the 1H-NMR spectrum, signals near 3.6 ppm and 4.0 ppm are respectively the ester group (—O—CH ₃ ) of the methyl methacrylate unit and the n-butyl acrylate unit. The content of the copolymerization component was determined from the ratio of the integral values of the ester group —O—CH ₂ —CH ₂ —CH ₂ —CH ₃ ).
(3) Calculation of glass transition temperature (Tg):
The glass transition temperature is a theoretical value calculated from the formula of FOX from the ratio of the monomer and each monomer used for the production of the copolymer.

Production Example 1
(Synthesis of block copolymer 1)
A 2 L three-necked flask was fitted with a three-way cock and the inside was replaced with nitrogen. At room temperature, 868 g of toluene, 43.4 g of 1,2-dimethoxyethane, isobutylbis (2,6-di-t-butyl-4-methylphenoxy) ) 60.0 g of a toluene solution containing 40.2 mmol of aluminum was added, and 3.68 g of a mixed solution of cyclohexane and n-hexane containing 6.37 mmol of sec-butyllithium was further added. Subsequently, 51.5 g of methyl methacrylate (hereinafter abbreviated as MMA) was added thereto, and the mixture was stirred at room temperature for 60 minutes. Subsequently, the internal temperature of the polymerization solution was cooled to −30 ° C., and 240 g of n-butyl acrylate (hereinafter abbreviated as nBA) was added dropwise over 2 hours. Next, 51.5 g of MMA was added, and after stirring overnight at room temperature, 3.50 g of methanol was added to terminate the polymerization reaction. The obtained reaction solution was poured into methanol, and the precipitate was collected by filtration and dried to obtain 340 g of triblock copolymer 1.

As a result of ¹ H-NMR measurement and GPC measurement, the triblock copolymer 1 is a PMMA-PnBA-PMMA triblock copolymer, and the weight average molecular weight (Mw) is 7.9 × 10 ⁴ . The number average molecular weight (Mn) was 6.2 × 10 ⁴ and the molecular weight distribution (Mw / Mn) was 1.27. PMMA-PnBA-PMMA represents polymethyl methacrylate-poly (n-butyl acrylate) -polymethyl methacrylate. The weight ratio of the monomer units of the triblock copolymer 1 was nBA / MMA = 70/30.

Production Example 2
(Synthesis of block copolymer 2)
A triblock copolymer 2 was obtained in the same manner as in Production Example 1 except that 2-ethylhexyl acrylate (hereinafter abbreviated as 2EHA) was used instead of nBA in Production Example 1.

As a result of ¹ H-NMR measurement and GPC, the triblock copolymer 2 is a triblock copolymer of PMMA-P2EHA-PMMA, and has a weight average molecular weight (Mw) of 9.2 × 10 ⁴ , The average molecular weight (Mn) was 7.3 × 10 ⁴ and the molecular weight distribution (Mw / Mn) was 1.26. PMMA-P2EHA-PMMA represents polymethyl methacrylate-polyethyl 2-ethylhexyl-polymethyl methacrylate. The weight ratio of the monomer units of the triblock copolymer 2 was 2EHA / MMA = 69/31.

Production Example 3
(Synthesis of block copolymer 3)
A nitrogen-substituted 500 L reactor was charged with 80.9 kg of nBA and 2.1 kg of t-butyl acrylate (hereinafter abbreviated as tBA) as monomers constituting the acrylic polymer block, and then cuprous bromide. 580 g was charged and stirring was started. Thereafter, a solution prepared by dissolving 583 g of diethyl 2,5-dibromoadipate in 7.3 kg of acetonitrile was charged, and maintained at 75 ° C. for 30 minutes, and then 70 g of pentamethyldiethylenetriamine was added. After adding 3 hours after adding pentamethyldiethylenetriamine as needed, 82.5 kg of toluene, 400 g of first chloride, 70 g of pentamethyldiethylenetriamine, and 35.6 kg of MMA were added. After completion of the reaction, 120 kg of toluene was added to dilute the reaction solution, and the reactor was cooled to terminate the polymerization. Toluene was added to the resulting acrylic block copolymer solution to make the polymer concentration 25% by weight. To this solution, 1.6 kg of p-toluenesulfonic acid monohydrate was added, the inside of the reactor was purged with nitrogen, and the mixture was stirred at 150 ° C. for 4 hours to convert the t-butyl group of tBA into a carboxyl group, and then triblock. Copolymer 3 was obtained.

As a result of ¹ H-NMR measurement and GPC, the triblock copolymer 3 is a triblock copolymer of PMMA-P [nBA / AA] -PMMA, and the weight average molecular weight (Mw) is 1.8 × 10. ^The number average molecular weight (Mn) was 1.3 × 10 ⁵ and the molecular weight distribution (Mw / Mn) was 1.38. PMMA-P [nBA / AA] -PMMA represents polymethyl methacrylate- [copolymer of n-butyl acrylate and acrylic acid] -polymethyl methacrylate. The weight ratio of the monomer units of the triblock copolymer 3 was nBA / AA / MMA = 69/2/29.

Production Example 4
(Synthesis of graft copolymer 4)
After placing 233 g of toluene, 100 g of nBA, 0.2 g of 2,2′-azobisisobutyronitrile at room temperature in a reaction vessel equipped with a cooling tube, a nitrogen introducing tube, a thermometer, and a stirrer, and performing nitrogen substitution The temperature was raised to 55 ° C. and a polymerization reaction was carried out for 6 hours to obtain a solution of n-butyl polyacrylate. 50 parts of a methyl methacrylate macromonomer having a methacryloyl group at the end group (manufactured by Toa Gosei Chemical Co., Ltd.) is added to 100 parts of this poly (n-butyl acrylate) solid solution, and toluene is used as a normal solution. Polymerization was performed to obtain a graft copolymer 4.

As a result of ¹ H-NMR measurement and GPC, the graft copolymer 4 has a weight average molecular weight (Mw) of 2.2 × 10 ⁵ and a number average molecular weight (Mn) of 1.7 × 10 ⁵ . The molecular weight distribution (Mw / Mn) was 1.29. The weight ratio of the monomer units was nBA / MMA = 67/33.

Production Example 5
(Synthesis of triblock copolymer 5)
A 2 L three-necked flask was fitted with a three-way cock and the inside was replaced with nitrogen. At room temperature, 868 g of toluene, 43.4 g of 1,2-dimethoxyethane, isobutylbis (2,6-di-t-butyl-4-methylphenoxy) ) 60.0 g of a toluene solution containing 40.2 mmol of aluminum was added, and 3.68 g of a mixed solution of cyclohexane and n-hexane containing 6.37 mmol of sec-butyllithium was further added. Subsequently, 46.4 g of MMA and 5.1 g of methyl acrylate (hereinafter abbreviated as MA) were added thereto, and the mixture was stirred at room temperature for 60 minutes. Subsequently, the internal temperature of the polymerization solution was cooled to −30 ° C., and a mixed solution of 192 g of nBA and 48 g of MA was added dropwise over 2 hours. Next, 46.4 g of MMA and 5.1 g of MA were added, and after stirring overnight at room temperature, 3.50 g of methanol was added to terminate the polymerization reaction. The obtained reaction solution was poured into methanol, and the precipitate was collected by filtration and dried to obtain 334 g of triblock copolymer 5.

As a result of ¹ H-NMR measurement and GPC measurement, the triblock copolymer 5 is a triblock copolymer of P [MMA / MA] -P [nBA / MA] -P [MMA / MA] The average molecular weight (Mw) was 12.1 × 10 ⁴ , the number average molecular weight (Mn) was 9.3 × 10 ⁴ , and the molecular weight distribution (Mw / Mn) was 1.30. P [MMA / MA] -P [nBA / MA] -P [MMA / MA] is a copolymer of [methyl methacrylate and methyl acrylate]-[copolymer of n-butyl acrylate and methyl acrylate. Polymer]-[copolymer of methyl methacrylate and methyl acrylate]. The weight ratio of the monomer units of the triblock copolymer 5 was nBA / MA / MMA = 56/17/27.

Example 1
<Formation of adhesive layer>
The triblock copolymer 1 obtained in Production Example 1 was dissolved in toluene to prepare a pressure-sensitive adhesive solution having a solid content of 30%, and then the pressure-sensitive adhesive solution was subjected to a release treatment (thickness 38 μm). ) Is applied by reverse roll coating so that the thickness of the pressure-sensitive adhesive layer after drying is 20 μm, heat-treated at 155 ° C. for 3 minutes to volatilize the solvent, Obtained.

<Optical film>
A wide view (WV) film manufactured by Fuji Photo Film Co., Ltd. was used. The WV film had a discotic liquid crystal layer in which discotic liquid crystal molecules were tilted and aligned on a cellulose polymer film that was a transparent substrate film.

In addition, the WV film was separated into an inclined alignment layer of discotic liquid crystal molecules, and the characteristics at λ = 590 nm were measured with KOBRA-21ADH manufactured by Oji Scientific Instruments. The in-plane maximum refractive index was nx, the refractive index in the direction orthogonal to the direction having the in-plane maximum refractive index was ny, and the refractive index in the thickness direction was nz. The thickness was d. The transparent support had Δnd = (nx−ny) × d = 12 nm and Rth = (nx−nz) × d = 100 nm. On the other hand, in the tilted alignment layer, the phase difference was measured by changing the incident angle from −50 ° to 50 ° in the direction in which the optical axis is tilted. Met.

After the saponification treatment of the transparent substrate film side of the WV film, the saponification treatment surface and a polyvinyl alcohol polarizer having a thickness of 20 μm (manufactured by Nitto Denko Corporation, SEG-5424WL) It bonded together with the adhesive agent. On the other hand, a transparent protective film (triacetyl cellulose film, thickness 80 μm) is bonded to the other surface of the polarizer with the same polyvinyl alcohol-based adhesive as described above, and an optical film having a polarizing plate (polarized light with an optical compensation layer) Board).

<Preparation of primer>
A phenolic antioxidant (Ciba Specialty Chemicals, Inc. A primer was prepared by adding 1 part of Irganox 1010) to 100 parts of the solid content of the solution.

<Preparation of adhesive optical film>
On the surface of the discotic liquid crystal layer of the polarizing plate with the optical compensation layer, the undercoat is applied and dried using a bar coater to form an undercoat layer (thickness 80 nm) having a coating amount of 0.2 cubic centimeters. did. Subsequently, the release sheet in which the said adhesive layer was formed was bonded to the undercoat layer, and the adhesive optical film was produced.

Example 2
In Example 1, in forming the pressure-sensitive adhesive layer, Example 1 was used except that instead of the triblock copolymer 1 obtained in Production Example 1, the triblock copolymer 2 obtained in Production Example 2 was used. In the same manner, an adhesive optical film was produced.

Example 3
In Example 1, in forming the pressure-sensitive adhesive layer, Example 1 was used except that the triblock copolymer 3 obtained in Production Example 3 was used instead of the triblock copolymer 1 obtained in Production Example 1. In the same manner, an adhesive optical film was produced.

Example 4
In Example 1, in forming the pressure-sensitive adhesive layer, Example 1 was used except that instead of the triblock copolymer 1 obtained in Production Example 1, the graft copolymer 4 obtained in Production Example 4 was used. Similarly, an adhesive optical film was produced.

Example 5
In Example 1, in forming the pressure-sensitive adhesive layer, Example 1 was used except that the triblock copolymer 5 obtained in Production Example 5 was used in place of the triblock copolymer 1 obtained in Production Example 1. In the same manner, an adhesive optical film was produced.

Comparative Example 1
In Example 1, an adhesive optical film was prepared in the same manner as in Example 1 except that no undercoat layer was provided in preparing the adhesive optical film.

Comparative Example 2
<Preparation of acrylic adhesive>
As a base polymer, an acrylic polymer having a weight average molecular weight of 16.5 million consisting of a random copolymer 6 of nBA: MMA = 70: 30 (weight ratio) (as a polymerization disclosure agent, 2,2′- An ethyl acetate solution (solid content 15.5%) containing 0.3 parts of azobisisobutyronitrile was used.

<Preparation of adhesive optical film>
In Example 1, the formation of the pressure-sensitive adhesive layer was carried out except that the solution of the random copolymer 6 obtained above was used instead of the solution of the triblock copolymer 1 obtained in Production Example 1. In the same manner as in Example 1, an adhesive optical film was produced.

Comparative Example 3
(Synthesis of block copolymer 7)
A triblock copolymer 7 was obtained in the same manner as in Production Example 1 except that n-butyl methacrylate (hereinafter abbreviated as nBMA) was used instead of MMA in Production Example 1.

As a result of ¹ H-NMR measurement and GPC, the triblock copolymer 7 is a triblock copolymer of PnBMA-PnBA-PnBMA, and the weight average molecular weight (Mw) is 1.2 × 10 ⁵ , The average molecular weight (Mn) was 9.2 × 10 ⁴ and the molecular weight distribution (Mw / Mn) was 1.30. Note that PnBMA-PnBA-PnBMA represents poly (n-butyl methacrylate)-(n-butyl polyacrylate)-(n-butyl polymethacrylate). The weight ratio of the monomer units of the triblock copolymer 5 was nBA / nBMA = 70/30.

<Preparation of adhesive optical film>
In Example 1, the formation of the pressure-sensitive adhesive layer was the same as Example 1 except that instead of the triblock copolymer 1 obtained in Production Example 1, the triblock copolymer 7 obtained above was used. Thus, an adhesive optical film was produced.

Reference example 1
<Preparation of acrylic adhesive>
As a base polymer, an acrylic polymer having a weight average molecular weight of 16.5 million consisting of a random copolymer 8 of nBA: 4-hydroxybutyl acrylate (hereinafter abbreviated as 4HBA) = 99: 1 (weight ratio) (as a polymerization disclosure agent, An ethyl acetate solution (15.5% solid content) containing 100 parts of monomer and synthesized using 0.3 part of 2,2′-azobisisobutyronitrile) was used. For 100 parts of the solid content of the acrylic polymer solution, 0.3 parts of dibenzoyl peroxide (manufactured by NOF Corporation, Nyper BMT40SV) and trimethylolpropane xylene diisocyanate (Mitsui Takeda Chemical Co., Ltd.) ), Takenate D110N) 0.02 part, and acetoacetyl group-containing silane coupling agent (manufactured by Soken Chemical Co., Ltd., A-100) 0.2 part, and a pressure-sensitive adhesive solution (solid content 12%) Prepared.

<Preparation of adhesive optical film>
In Example 1, in forming the pressure-sensitive adhesive layer, the pressure-sensitive adhesive solution containing the random copolymer 8 obtained above was used instead of the solution of the triblock copolymer 1 obtained in Production Example 1. Except for this, an adhesive optical film was produced in the same manner as in Example 1.

The following evaluation was performed on the adhesive optical film obtained above. The results are shown in Table 1.

(Adhesion between adhesive layer and optical film substrate)
The above adhesive optical film is cut to a size of 25 mm × 150 mm, and bonded so that the adhesive layer surface of this adhesive film and the deposition surface of the deposited film of indium-tin oxide deposited on the surface of the 50 μm thick polyethylene terephthalate film are in contact with each other. And then left in an environment of 23 ° C./60% RH for 20 minutes or more. Thereafter, the end of the polyethylene terephthalate film was peeled off by hand, and after confirming that the adhesive was adhered to the polyethylene terephthalate film side, it was rotated 180 ° using a tensile tester AG-1 manufactured by Shimadzu Corporation. The stress (N / 25 mm) when peeled at a speed of 300 mm / min was measured (25 ° C.).

(Adhesive strength and reworkability)
The pressure-sensitive adhesive optical film was cut to a width of 25 mm, and attached to a non-alkali glass (Corning Corp., 1737) having a thickness of 0.7 mm by one reciprocating press with a 2 kg roller. When the sample was cured for 1 hour at 23 ° C. (initial) and for 1 year (after 1 year), each was peeled off at a peeling angle of 180 ° and a peeling speed of 300 mm / min with a tensile tester. The adhesive force (N / 25 mm) was measured. Moreover, the state of the glass surface after the peeling was visually evaluated according to the following criteria. In addition, the said evaluation is performed 50 times and adhesive force is the average value.
◎: Peelable without adhesive residue (Adhesive strength: less than 20N / 25mm)
○: Peelable without adhesive residue but heavy peeling (adhesive strength: 20N / 25mm or more)
Δ: Adhesive residue generated (0-5 sheets / 50 sheets).
X: Adhesive residue generated (6 sheets or more / 50 sheets).

The glass transition temperature of each (co) polymer segment in the triblock copolymer is
PMMA: 105 ° C.
PnBA: -45 ° C
P2EHA: -55 ° C
P [MMA / MA]: 92 ° C.
P [nBA / MA]: -36 ° C
PnBMA: 20 ° C.

A Optical film B Undercoat layer C Adhesive layer A11 Transparent substrate film A12 Alignment film A13 Liquid crystal optical compensation layer (discotic liquid crystal layer)
A14 Polarizer A15 Transparent protective film

Claims (12)

1. In an optical film, an adhesive optical film in which an adhesive layer is provided via an undercoat layer,
   The pressure-sensitive adhesive layer has, as a base polymer, a (meth) acrylic polymer (A) segment having a glass transition temperature of 0 ° C. or lower and a (meth) acrylic polymer (B) segment having a glass transition temperature of 40 ° C. or higher. Formed of a pressure-sensitive adhesive containing a block copolymer or a graft copolymer, and
   The undercoat layer contains a polymer and is an adhesive optical film.
2. In the (meth) acrylic polymer (A) segment, 50% by weight or more of the total monomer units is alkyl acrylate, and in the (meth) acrylic polymer (B) segment, 15% by weight or more of the total monomer units is methacrylic. The pressure-sensitive adhesive optical film according to claim 1, which is an acid alkyl ester.
3. The base polymer contained in the adhesive is a BAB triblock copolymer (where A is a (meth) acrylic polymer (A) segment, B is a (meth) acrylic polymer (B) segment) The pressure-sensitive adhesive optical film according to claim 1 or 2, wherein
4. The pressure-sensitive adhesive optical film according to any one of claims 1 to 3, wherein the polymer of the undercoat layer is a polymer having a primary amino group at the terminal.
5. The pressure-sensitive adhesive optical film according to claim 4, wherein the polymer having a primary amino group at the terminal is a poly (meth) acrylic ester having a primary amino group at the terminal.
6. 6. The pressure-sensitive adhesive optical film according to claim 4, wherein the primary amino group in the polymer having a primary amino group at the terminal is derived from a polyethyleneimine-based material.
7. 7. The pressure-sensitive adhesive optical film according to claim 1, wherein the undercoat layer contains 0.01 to 500 parts by weight of an antioxidant with respect to 100 parts by weight of the polymers.
8. The pressure-sensitive adhesive optical film according to claim 7, wherein the antioxidant is at least one selected from phenolic, phosphorus, sulfur and amine antioxidants.
9. The optical film has a liquid crystal optical compensation layer on one side of a transparent substrate film, and the liquid crystal optical compensation layer is provided with an adhesive layer through an undercoat layer. The pressure-sensitive adhesive optical film according to any one of 1 to 8.
10. The pressure-sensitive adhesive optical film according to claim 9, wherein the liquid crystal optical compensation layer is a discotic liquid crystal layer.
11. The pressure-sensitive adhesive optical film according to claim 9 or 10, wherein a polarizer is laminated on one side of the transparent base film on the side where the liquid crystal optical compensation layer is not formed.
12. An image display device using at least one adhesive optical film according to any one of claims 1 to 11.
    

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