JP2004341155A - Adhesive applied optical member, method for manufacturing the same and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive applied optical member with an adhesive layer stacked on at least one surface of an optical member, wherein the adhesion of the adhesive layer to the optical member is good even after long-term storage under severe conditions. <P>SOLUTION: In the adhesive applied optical member with an adhesive layer 2 stacked on at least one surface of an optical member 1, the adhesive layer 2 is stacked by way of a functional-group-containing polymer layer 3a and a functional-group-containing polymer layer 3b irradiated with UV. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

表１において、密着性（１）に示されるように、本発明の粘着型光学部材は糊残りなく剥離可能であり、再剥離性に優れていることが分かる。また密着力（２）に示されるように、光学部材と粘着剤層との密着性は両面テープへの接着力よりも大きいことが分かる。これから過酷な条件が要求される状況下においても耐久性がよく、光学部材と粘着剤層との間で剥がれや浮きを抑えられものと認められる。
【図面の簡単な説明】
【図１】本発明の粘着剤付光学部材の断面図の一例である。
【図２】本発明の粘着剤付光学部材の製造方法の一例を示す断面図である。
【符号の説明】
１ 光学部材
２ 粘着剤層
３ａ 官能基含有ポリマー層
３ｂ 紫外線照射された官能基含有ポリマー層
４ 剥離処理基材[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical member with a pressure-sensitive adhesive in which a pressure-sensitive adhesive layer is laminated on at least one surface of the optical member, and a method for manufacturing the same. Further, the present invention relates to an image display device such as a liquid crystal display device, an organic EL display device, or a PDP using the optical member with an adhesive. Examples of the optical member include a polarizing plate, a retardation plate, an optical compensation film, a brightness enhancement film, and a laminate of these.
[0002]
[Prior art]
An optical member used for a liquid crystal display device or the like, for example, a polarizing plate or a retardation plate is attached to a liquid crystal cell using an adhesive. Usually, an optical member with an adhesive in which an adhesive layer is laminated on the optical member is used. The material used for the optical member has a large expansion and contraction under a heating condition and a humidifying condition, and therefore, it tends to be lifted or peeled off after sticking. Therefore, the pressure-sensitive adhesive for optical members is required to have durability that can be used under heating conditions and humidifying conditions.
[0003]
In addition, when a foreign substance bites into the bonding surface or the position of the bonding member is misaligned during bonding of the optical member, the optical member is peeled off from the liquid crystal cell and reused. When such an optical member is peeled off from the liquid crystal cell, it is necessary that the gap of the liquid crystal cell be changed or that the optical member does not come into an adhesive state such that the optical member is broken, that is, a re-peeling property that can easily peel off the optical member is required. You.
[0004]
However, when an adhesive is designed with an emphasis on durability, the adhesiveness between the optical member and the adhesive layer tends to be insufficient. Therefore, when the optical member is peeled off from the liquid crystal cell, the adhesive remains in the liquid crystal cell and the removability is poor. In addition, if the adhesion between the optical member and the pressure-sensitive adhesive layer is insufficient, if the expansion and contraction of the optical member under heating or humidifying conditions increases, floating or peeling occurs between the optical member and the pressure-sensitive adhesive. .
[0005]
As a method of improving the adhesion between the optical member and the adhesive layer, a method of performing a corona treatment or a plasma treatment on the adhesive layer forming surface of the optical member, an acrylic resin between the optical member and the adhesive layer, a urethane resin, Examples thereof include a method of forming an anchor layer with an undercoating agent such as an epoxy resin, and a method of using a crosslinking agent in an adhesive.
[0006]
For example, a method has been proposed in which a polarizing plate is subjected to a heat treatment before the pressure-sensitive adhesive layer is attached to the polarizing plate (see Patent Document 1). According to such a method, it is possible to reduce the residual solvent in triacetyl cellulose which is a protective film of the polarizing plate, which is a factor inhibiting the reaction of the isocyanate compound which is a crosslinking agent in the pressure-sensitive adhesive layer. It is disclosed that the degree of crosslinking of the agent layer is stabilized and the adhesion between the pressure-sensitive adhesive layer and triacetyl cellulose is improved.
[0007]
When the pressure-sensitive adhesive layer containing an isocyanate-based cross-linking agent is bonded to a polarizing plate using triacetyl cellulose as a protective film, the bonding temperature is set to 50 to 70 ° C. A method of curing for 24 hours has been proposed (see Patent Document 2). According to this method, it is disclosed that the adhesion between the pressure-sensitive adhesive layer and triacetyl cellulose is improved.
[0008]
In addition, a method has been proposed in which a surface of an adhesive layer is subjected to a surface activation treatment such as a corona treatment, and is then bonded to an optical member such as a polarizing plate or a retardation plate (see Patent Document 3). According to such a method, it is disclosed that the adhesion between the pressure-sensitive adhesive layer and the optical member can be improved.
[0009]
In Patent Literature 1 and Patent Literature 2, the types of the pressure-sensitive adhesive and the optical member are limited. Even when the method described in these Patent Documents is applied to a combination of another pressure-sensitive adhesive and an optical member, sufficient adhesion is obtained. Often cannot be expressed. On the other hand, Patent Literature 3 discloses an effect of improving the adhesive strength by performing a surface activation treatment on the pressure-sensitive adhesive side instead of performing a surface treatment on a conventional optical member. I do not have.
[0010]
As described above, various methods have been tried to improve the adhesiveness between the pressure-sensitive adhesive layer and the optical member, but any of the methods has improved the adhesiveness to some extent as compared with the case where the method is not performed. . However, there are cases where there is no effect at all when the adhesive is changed or depending on the type of the optical member. Therefore, there is a problem that a phenomenon such as adhesive residue occurs at the time of re-peeling. In particular, when the optical member with the adhesive is bonded to the liquid crystal cell and stored in a severe condition for a long period, the adhesive force between the adhesive layer and the adherend such as the liquid crystal cell is greatly increased. At the time of re-peeling, a phenomenon such as adhesive residue is likely to occur. In addition, floating and peeling between the pressure-sensitive adhesive layer and the optical member are likely to occur.
[0011]
[Patent Document 1]
JP-A-9-227841
[Patent Document 2]
JP-A-11-199838
[Patent Document 3]
JP-A-7-174918
[0012]
[Problems to be solved by the invention]
The present invention is an optical member with a pressure-sensitive adhesive in which a pressure-sensitive adhesive layer is laminated on at least one surface of the optical member, and adheres to the pressure-sensitive adhesive layer even when stored in a severe condition for a long time. It is an object to provide an optical member with a pressure-sensitive adhesive having good properties. Another object of the present invention is to provide a method for producing the optical member with a pressure-sensitive adhesive.
[0013]
Still another object of the present invention is to provide an image display device using the optical member with an adhesive.
[0014]
[Means for Solving the Problems]
Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and have found that the above-mentioned object can be achieved by the following optical member with a pressure-sensitive adhesive, and have completed the present invention. That is, the present invention is as described below.
[0015]
1. An optical member with an adhesive in which an adhesive layer (2) is laminated on at least one surface of the optical member (1),
The optical member with a pressure-sensitive adhesive, wherein the pressure-sensitive adhesive layer (2) is laminated via a functional group-containing polymer layer (3a) and a functional group-containing polymer layer (3b) irradiated with ultraviolet rays.
[0016]
2. From the optical member (1) side, a functional group-containing polymer layer (3a), a functional group-containing polymer layer (3b) irradiated with ultraviolet rays are sequentially laminated, and then an adhesive layer (2) is laminated. 2. The optical member with a pressure-sensitive adhesive as described in 1 above.
[0017]
3. 3. The adhesive according to the above item 1 or 2, wherein the functional group-containing polymer used for forming the functional group-containing polymer layer (3a) and the functional group-containing polymer layer (3b) irradiated with ultraviolet rays is an amino group-containing polymer. Optical member with agent.
[0018]
4. 4. The optical member with a pressure-sensitive adhesive according to the above item 3, wherein the amino group-containing polymer is a polyethyleneimine-based polymer.
[0019]
5. Any of the above items 1 to 4, wherein the total of the thickness of the functional group-containing polymer layer (3a) and the thickness of the functional group-containing polymer layer (3b) irradiated with ultraviolet rays is 0.04 to 0.4 µm. 4. The optical member with a pressure-sensitive adhesive according to item 1.
[0020]
6. The pressure-sensitive adhesive optical member according to any one of the above items 1 to 5, wherein the pressure-sensitive adhesive layer (2) is formed of an acrylic pressure-sensitive adhesive.
[0021]
7. The acrylic pressure-sensitive adhesive contains 0.01 to 1 part by weight of a silane coupling agent with respect to 100 parts by weight of the acrylic polymer, and the pressure-sensitive adhesive layer (2) has a solvent-insoluble content of 30 to 30 parts by weight. 7. The optical member with a pressure-sensitive adhesive according to the above item 6, wherein the content is 90% by weight.
[0022]
8. Forming a functional group-containing polymer layer (3a) on at least one surface of the optical member (1);
Forming a pressure-sensitive adhesive layer (2) on the release-treated substrate (4) and then forming a functional group-containing polymer layer (3a);
A step of irradiating one of the functional group-containing polymer layers (3a) with ultraviolet light to form a functional group-containing polymer layer (3b) irradiated with ultraviolet light;
Bonding the functional group-containing polymer layer (3a) that has not been irradiated with the ultraviolet ray and the functional group-containing polymer layer (3b) that has been irradiated with the ultraviolet ray;
8. The method for producing an optical member with a pressure-sensitive adhesive according to any one of the above items 1 to 7, wherein
[0023]
9. 8. An image display device using at least one optical member with a pressure-sensitive adhesive according to any one of 1 to 7 above.
[0024]
(Action / Effect)
In the optical member with a pressure-sensitive adhesive of the present invention, the optical member (1) and the pressure-sensitive adhesive layer (2) are interposed via the functional group-containing polymer layer (3a) and the functional group-containing polymer layer (3b) irradiated with ultraviolet rays. Laminated. By interposing the polymer layer (3a) and the polymer layer (3b), the adhesion between the optical member (1) and the pressure-sensitive adhesive layer (2) is greatly improved.
[0025]
Therefore, the optical member with a pressure-sensitive adhesive of the present invention, when attached to a liquid crystal cell, after a long time such as going through various steps, or when stored for a long time under severe conditions such as high temperature Also, since the adhesiveness between the optical member (1) and the pressure-sensitive adhesive layer (2) is good, the optical member (1) can be cleanly peeled from the liquid crystal cell without the adhesive remaining on the liquid crystal cell, and re-peeled. The properties are good. Furthermore, the adhesion between the optical member (1) and the pressure-sensitive adhesive layer (2) is good, and even under severe conditions, the occurrence of floating or peeling between the optical member (1) and the pressure-sensitive adhesive layer (2) is suppressed. Can be
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
As shown in FIG. 1, the optical member with an adhesive of the present invention has an optical member (1) and an adhesive layer (2) laminated thereon. The optical member (1) and the pressure-sensitive adhesive layer (2) are laminated via a functional group-containing polymer layer (3a) and a functional group-containing polymer layer (3b) irradiated with ultraviolet rays. The functional group-containing polymer layer (3a) is preferably laminated on the surface of the functional group-containing polymer layer (3b) irradiated with ultraviolet rays. The order of lamination of the functional group-containing polymer layer (3a) and the functional group-containing polymer layer (3b) irradiated with ultraviolet light is not particularly limited, but as shown in FIG. (3a), it is preferable that the functional group-containing polymer layer (3b) irradiated with ultraviolet rays is laminated in order, and then the pressure-sensitive adhesive layer (2) is laminated, because the adhesion is good. Further, as shown in FIG. 1, a release-treated substrate (4) such as a release sheet can be provided on the pressure-sensitive adhesive layer (2), which is the outermost layer.
[0027]
The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer (2) of the pressure-sensitive adhesive optical member of the present invention is not particularly limited, and various pressure-sensitive adhesives such as a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive are used. An acrylic pressure-sensitive adhesive that is colorless and transparent and has good adhesion to a liquid crystal cell or the like is generally used. The base polymer of the pressure-sensitive adhesive preferably has a functional group that reacts with a functional group contained in the polymer forming the functional group-containing polymer layer (3a) or (3b).
[0028]
The acrylic pressure-sensitive adhesive has, as a base polymer, an acrylic polymer having an alkyl (meth) acrylate monomer unit as a main skeleton. In addition, (meth) acrylate means acrylate and / or methacrylate, and has the same meaning as (meth) in the present invention. The average number of carbon atoms of the alkyl group of the alkyl (meth) acrylate constituting the main skeleton of the acrylic polymer is preferably about 1 to 12. Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate. , Ethyl (meth) acrylate, butyl, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, and the like. These can be used alone or in combination. Of these, alkyl (meth) acrylates having 1 to 9 carbon atoms in the alkyl group are preferred.
[0029]
A functional group is appropriately introduced into a base polymer such as the acrylic polymer. Examples of the functional group include a carboxyl group, a hydroxyl group, an epoxy group, and an isocyanate group. The acrylic polymer having a functional group usually contains a monomer unit having the functional group. Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, and itaconic acid. Examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, N-methylol (meth) acrylamide, hydroxybutyl (meth) acrylate, and hydroxyhexyl (meth) acrylate. Examples of the monomer containing an epoxy group include glycidyl (meth) acrylate.
[0030]
The ratio of the monomer unit having the functional group in the acrylic polymer is not particularly limited, but is a weight ratio (a) to the monomer unit (A) (excluding the monomer unit (a)) constituting the acrylic polymer. / A) is preferably about 0.001 to 0.12, more preferably 0.005 to 0.1.
[0031]
Further, a monomer unit having an N element or the like can be introduced into the acrylic polymer. Examples of the N element-containing monomer include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylamino Examples include propyl (meth) acrylamide, (meth) acryloylmorpholine, (meth) acetonitrile, vinylpyrrolidone, N-cyclohexylmaleimide, itaconimide, and N, N-dimethylaminoethyl (meth) acrylamide. In addition, acrylic polymers include, in a range that does not impair the performance of the adhesive, vinyl acetate, vinyl styrene propionate, styrene and its derivatives, mono- or diesters of maleic acid, oligoester acrylates, ε-caprolactone acrylate, and the like. It can also be used. These monomers can be used alone or in combination of two or more.
[0032]
The average molecular weight of the acrylic polymer is not particularly limited, but the weight average molecular weight (GPC) is preferably about 300,000 to 2.5 million. It is a polymer having a glass transition point of 250K or lower. It is preferable to set the glass transition temperature of the polymer to 250K or lower. An excessively high glass transition temperature is not preferable because the adhesiveness of the pressure-sensitive adhesive is inferior.
[0033]
The acrylic polymer can be produced by various known methods. For example, a radical polymerization method such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method can be appropriately selected. As the radical polymerization initiator, various known azo-based and peroxide-based initiators can be used. The reaction temperature is usually about 50 to 85 ° C., and the reaction time is about 1 to 8 hours. As a solvent used in the solution polymerization method, for example, an organic solvent such as ethyl acetate and toluene is used. The solution concentration is usually about 20 to 80% by weight. Further, in view of recent environmentally conscious movements, a method that does not use an organic solvent, such as a suspension polymerization method and an emulsion polymerization method, is preferably used. The obtained acrylic polymer is in a solution state, an aqueous dispersion state, a solid state that can be flowed by heating, and the like.
[0034]
As the acrylic pressure-sensitive adhesive, various ones containing the above-mentioned acrylic polymer as a base polymer, which are appropriately adjusted by appropriately mixing a crosslinking agent, an additive, and the like, can be used without any particular limitation.
[0035]
The acrylic pressure-sensitive adhesive contains, for example, 0.01 to 1 part by weight of a silane coupling agent based on 100 parts by weight of an acrylic polymer, and the pressure-sensitive adhesive layer (2) has a solvent-insoluble content. Is preferably adjusted to 30 to 90% by weight from the viewpoint of adhesion to a liquid crystal cell, durability, and removability.
[0036]
As the silane coupling agent, a conventionally known silane coupling agent can be used without any particular limitation. For example, epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyl Amino group-containing silane coupling agents such as trimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine Silane coupling agents containing (meth) acrylic groups such as 3-, 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane, and silane coupling agents containing incinate groups such as 3-isocyanatopropyltriethoxysilane. Given . The silane coupling agent is added in an amount of 0.01 to 1 part by weight, preferably 0.02 to 0.6 part by weight, based on 100 parts by weight of the solid content of the acrylic polymer. When the amount is too large, the adhesive strength to the liquid crystal cell is increased and the removability may be reduced. On the other hand, when the amount is too small, the durability may be reduced.
[0037]
As the crosslinking agent, a polyfunctional compound capable of forming a crosslinked structure by reacting with a functional group of the acrylic polymer is used. Examples of the crosslinking agent include polyisocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, and adducts of these diisocyanate compounds to various polyols, epoxy compounds, aziridine compounds, melamine compounds, metal salts, metal chelate compounds, and the like. . When a hydroxyl group is introduced into the acrylic polymer, it is preferable to use a polyisocyanate compound as a crosslinking agent.
[0038]
When the acrylic polymer is in a solution state, the crosslinking agent may be an isocyanate compound or an epoxy compound. Metal chelates, aziridine compounds and the like are preferably used. As the crosslinking agent, a photo-crosslinking agent or the like can be added. In addition, a method of introducing a functional group which reacts with light into an acrylic polymer and cross-linking with an ultraviolet ray or radiation cross-linking with an electron beam can also be performed. On the other hand, when the acrylic polymer is an aqueous dispersion, a system that does not require a crosslinking reaction around the aqueous dispersion can be used.
[0039]
The pressure-sensitive adhesive layer preferably has a solvent-insoluble content of 30 to 90% by weight from the viewpoint of durability and the like. More preferably, it is 35 to 85% by weight. When the solvent insoluble content is small, the durability tends to be poor, and when too large, the stress relaxation property tends to be poor. When a crosslinking agent is blended, it is preferable to adjust the blending amount of the crosslinking agent so that the solvent-insoluble content of the crosslinked pressure-sensitive adhesive layer is 35 to 90% by weight. In order to adjust the solvent-insoluble content in this way, although it differs depending on the material to be used, the amount of the crosslinking agent is usually 0.01 to 5 parts by weight, usually 100 parts by weight of the acrylic polymer. The content is preferably 0.02 to 2 parts by weight.
[0040]
The solvent-insoluble content of the pressure-sensitive adhesive layer is calculated based on the dry weight W ₁ (G) The adhesive layer was immersed in ethyl acetate at room temperature (23 ° C.) for 7 days, and then taken out and dried. ₂ (G) is a value calculated by the following equation.
Solvent insolubles (% by weight) = (W ₂ / W ₁ ) × 100
More specifically, the solvent-insoluble matter is determined by the following method. That is, a solution of the pressure-sensitive adhesive composition is applied on the release-treated film, dried at 110 ° C. for 5 minutes, and aged at 50 ° C. for 24 hours. ₁ (G) Collect. Next, after leaving this adhesive in ethyl acetate for 7 days at room temperature, the gel was taken out, dried at 130 ° C. for 2 hours, and the weight W ₂ (G) is measured. This W ₁ And W ₂ Is substituted into the above equation to determine the solvent-insoluble matter.
[0041]
Examples of the base polymer of the rubber-based pressure-sensitive adhesive include natural rubber, isoprene-based rubber, styrene-butadiene-based rubber, recycled rubber, polyisobutylene-based rubber, styrene-isoprene-styrene-based rubber, and styrene-butadiene-styrene-based rubber. Examples of the base polymer of the silicone-based pressure-sensitive adhesive include dimethylpolysiloxane and diphenylpolysiloxane, and those in which a functional group reactive with an amino group such as a carboxyl group is introduced. It can be suitably used.
[0042]
Further, the pressure-sensitive adhesive may include, if necessary, a tackifier, a plasticizer, a glass fiber, a glass bead, a metal powder, a filler composed of other inorganic powders, a pigment, a colorant, a filler, an antioxidant. Various additives such as agents and ultraviolet absorbers can be used as appropriate. Further, a pressure-sensitive adhesive layer or the like which contains fine particles and exhibits light diffusibility may be used.
[0043]
A functional group-containing polymer layer (3a) and a functional group-containing polymer layer (3b) irradiated with ultraviolet rays are interposed between the optical member (1) and the pressure-sensitive adhesive layer (2). The functional group-containing polymer forming the functional group-containing polymer layer (3a) and the functional group-containing polymer layer (3b) irradiated with ultraviolet rays may be the same or different.
[0044]
As the functional group-containing polymer, a polymer into which a functional group such as an amino group, a carboxyl group, or a hydroxyl group is introduced can be used without any particular limitation. These functional group-containing polymers include a homopolymer of a monomer having a functional group, a copolymer with various other monomers, a graft polymer, a block polymer and the like. In the case where the functional group-containing polymer is a copolymer, a graft polymer, a block polymer, or the like, the effect of adhesion decreases as the number of functional groups decreases. Therefore, the functional group-containing polymer preferably has a functional group equivalent of 0.5 meq / g or more, more preferably 0.8 meq / g or more. The functional group equivalent is the amount of the functional group per 1 g of the polymer. For example, when the functional group is derived from the functional group monomer, the weight of the functional group monomer in 1 g of the polymer is divided by the molecular weight of the functional group monomer. (Equivalent / g).
[0045]
The average molecular weight of the functional group-containing polymer is not particularly limited, but preferably has a number average molecular weight of about 5,000 to 300,000 as measured by a viscosity method. More preferably, it is about 8000 to 200,000. If the number average molecular weight is too large, unevenness may occur in the polymer layer (3a) or (3b).
[0046]
As the functional group-containing polymer, an amino group-containing polymer is preferable. Examples of the amino group-containing polymer include polyamine compounds such as polyethyleneimine-based polymers and allylamine-based compounds. The mode of use of the amino group-containing polymer may be any of a solvent-soluble type, an aqueous dispersion type, and a water-soluble type. As the amino group-containing polymer, a polyethyleneimine-based polymer is preferable because of good adhesion.
[0047]
Examples of the polyethyleneimine-based polymer include polyethyleneimine. Other examples include a copolymer with another monomer; a graft polymer with another polymer such as polyacrylate, polyacrylic acid, and polyvinyl alcohol; and an ethyleneimine adduct to another polymer. As the polyethyleneimine-based polymer, polyethyleneimine is preferable.
[0048]
For example, examples of commercially available products of polyethyleneimine include Epomin SP series (SP-003, SP006, SP012, SP018, SP103, SP110, SP200, etc.) manufactured by Nippon Shokubai Co., Ltd., and Epomin P-1000. Of these, epomin P-1000 is preferred. Further, there may be mentioned Polyment series (SK-1000, NK-100PM, NK-200PM, NK-350, NK-380) manufactured by Nippon Shokubai Co., Ltd.
[0049]
The allylamine-based compound is not particularly limited, for example, diallylamine hydrochloride-sulfur dioxide copolymer, diallylmethylamine hydrochloride copolymer, polyallylamine hydrochloride, allylamine-based compounds such as polyallylamine, diethylenetriamine and the like Condensates of polyalkylene polyamines and dicarboxylic acids, and epihalohydrin adducts thereof, polyvinylamine, and the like can be given. Allylamine-based compounds, particularly polyallylamine, are preferred because they are soluble in water / alcohol.
[0050]
In forming the functional group-containing polymer layer (3a), a compound that reacts with the functional group-containing polymer may be mixed and crosslinked to improve the strength. Examples of the amino group-containing polymer include an epoxy compound.
[0051]
The functional group-containing polymer layer (3b) that has been irradiated with ultraviolet light is obtained by irradiating the functional group-containing polymer layer (3a) with a thin layer and irradiating it with ultraviolet light. Even if the functional group-containing polymer layers (3a) that have not been treated with ultraviolet rays are laminated, the effect of improving the adhesion is not sufficient. The ultraviolet irradiation is usually performed in an atmosphere containing oxygen, usually in the air. The irradiation amount of the ultraviolet light is 60 mJ / cm ² More than 80 mJ / cm ² The above is preferable. Usually, 60 to 500 mJ / cm ² Range. The irradiation light amount can be based on the UV-C light amount of UV Power Pack (manufactured by Fusion UV Systems Japan Co., Ltd.).
[0052]
As the optical member (1), a member used for forming an image display device such as a liquid crystal display device is used, and the type thereof is not particularly limited. For example, an optical member includes a polarizing plate. A polarizing plate having a transparent protective film on one or both sides of a polarizer is generally used.
[0053]
The polarizer is not particularly limited, and various types can be used. Examples of the polarizer include a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, an ethylene-vinyl acetate copolymer-based partially saponified film, and a dichromatic dye such as iodine or a dichroic dye. And uniaxially stretched by adsorbing a reactive substance, and a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol and a dehydrochlorination product of polyvinyl chloride. Among these, a polarizer composed of a polyvinyl alcohol-based film and a dichroic substance such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.
[0054]
A polarizer obtained by dyeing a polyvinyl alcohol-based film with iodine and uniaxially stretching can be produced by, for example, dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine, and stretching the film to 3 to 7 times its original length. If necessary, it can be immersed in an aqueous solution of potassium iodide or the like which may contain boric acid, zinc sulfate, zinc chloride or the like. Further, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. By washing the polyvinyl alcohol-based film with water, dirt on the surface of the polyvinyl alcohol-based film and an anti-blocking agent can be washed, and by swelling the polyvinyl alcohol-based film, the effect of preventing unevenness such as uneven dyeing can be obtained. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be stretched and then dyed with iodine. Stretching can be performed in an aqueous solution of boric acid or potassium iodide or in a water bath.
[0055]
As a material for forming the transparent protective film provided on one or both surfaces of the polarizer, a material having excellent transparency, mechanical strength, heat stability, moisture shielding property, isotropy and the like is preferable. 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, and styrene such as polystyrene and acrylonitrile-styrene copolymer (AS resin). Polymers, polycarbonate polymers and the like. In addition, polyethylene, polypropylene, polyolefin having a cyclo- or norbornene structure, polyolefin-based polymers such as ethylene-propylene copolymer, vinyl chloride-based polymers, amide-based polymers such as nylon and aromatic polyamide, imide-based polymers, and sulfone-based polymers , A polyether sulfone polymer, a polyether ether ketone polymer, a polyphenylene sulfide polymer, a vinyl alcohol polymer, a vinylidene chloride polymer, a vinyl butyral polymer, an arylate polymer, a polyoxymethylene polymer, an epoxy polymer, or the above. Blends of polymers and the like are also examples of the polymer forming the transparent protective film. The transparent protective film can also be formed as a cured layer of a thermosetting resin or an ultraviolet curing resin such as an acrylic, urethane, acrylic urethane, epoxy or silicone resin.
[0056]
Further, polymer films described in JP-A-2001-343529 (WO 01/37007), for example, (A) a thermoplastic resin having a substituted and / or unsubstituted imide group in the side chain, and (B) a thermoplastic resin having a side chain And / or an unsubstituted phenyl and a resin composition containing a thermoplastic resin having a nitrile group. A specific example is a film of a resin composition containing an alternating copolymer of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a film composed of a mixed extruded product of a resin composition or the like can be used.
[0057]
Although the thickness of the protective film can be determined as appropriate, it is generally about 1 to 500 μm from the viewpoint of workability such as strength and handleability, thinness, and the like. In particular, it is preferably from 1 to 300 µm, more preferably from 5 to 200 µm.
[0058]
Further, it is preferable that the protective film has as little coloring as possible. Therefore, Rth = [(nx + ny) / 2−nz] · d (where nx and ny are the main refractive indices 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 retardation value in the film thickness direction of -90 nm to +75 nm is preferably used. By using a film having a retardation value (Rth) in the thickness direction of -90 nm to +75 nm, coloring (optical coloring) of the polarizing plate caused by the protective film can be almost eliminated. The thickness direction retardation value (Rth) is more preferably -80 nm to +60 nm, and particularly preferably -70 nm to +45 nm.
[0059]
As the protective film, a cellulosic polymer such as triacetyl cellulose is preferable from the viewpoints of polarization characteristics and durability. Particularly, a triacetyl cellulose film is preferable. In the case where protective films are provided on both sides of the polarizer, a protective film made of the same polymer material may be used on both sides thereof, or a protective film made of a different polymer material may be used. Usually, the polarizer and the protective film are in close contact with each other via a water-based 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-based, a water-based polyurethane, and a water-based polyester.
[0060]
The surface of the transparent protective film on which the polarizer is not adhered may be subjected to a hard coat layer, an antireflection treatment, a treatment for preventing sticking, and a treatment for diffusion or antiglare.
[0061]
The hard coat treatment is performed for the purpose of preventing scratches on the surface of the polarizing plate, for example, by applying a suitable ultraviolet-curable resin such as an acrylic resin or a silicone resin to a cured film having excellent hardness and sliding properties, etc., as a transparent protective film. It can be formed by a method of adding to the surface of. The anti-reflection treatment is performed for the purpose of preventing reflection of external light on the polarizing plate surface, and can be achieved by forming an anti-reflection film or the like according to the related art. In addition, the anti-sticking treatment is performed for the purpose of preventing adhesion to an adjacent layer.
[0062]
The anti-glare treatment is performed for the purpose of preventing external light from being reflected on the surface of the polarizing plate and hindering the visibility of light transmitted through the polarizing plate, and is, for example, a roughening method using a sand blast method or an embossing method. The transparent protective film can be formed by giving a fine uneven structure to the surface of the transparent protective film by an appropriate method such as a method of mixing transparent fine particles. As the fine particles to be contained in the formation of the surface fine uneven structure, for example, a conductive material composed of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide and the like having an average particle size of 0.5 to 50 μm. Transparent fine particles such as inorganic fine particles that may be used and organic fine particles made of a crosslinked or uncrosslinked polymer or the like are used. When forming the fine surface unevenness structure, the amount of the fine particles to be used is generally about 2 to 50 parts by weight, preferably 5 to 25 parts by weight, per 100 parts by weight of the transparent resin forming the fine surface unevenness structure. The anti-glare layer may also serve as a diffusion layer (such as a viewing angle expanding function) for diffusing light transmitted through the polarizing plate to increase the viewing angle or the like.
[0063]
The anti-reflection layer, anti-sticking layer, diffusion layer, anti-glare layer and the like can be provided on the transparent protective film itself, or can be separately provided as an optical layer separately from the transparent protective film.
[0064]
Examples of the optical member of the present invention include liquid crystal display devices such as a reflection plate, a semi-transmission plate, a retardation plate (including a wavelength plate such as や and １ ／), a viewing angle compensation film, and a brightness enhancement film. An optical layer that may be used for formation may be used. These can be used alone as the optical member of the present invention, and can be used as a single layer or two or more layers laminated on the polarizing plate in practical use.
[0065]
In particular, a reflective polarizing plate or a semi-transmitting polarizing plate in which a reflecting plate or a transflective reflecting plate is further laminated on a polarizing plate, an elliptically polarizing plate or a circular polarizing plate in which a retardation plate is further laminated on a polarizing plate, a polarized light A wide viewing angle polarizing plate obtained by further laminating a viewing angle compensation film on a plate, or a polarizing plate obtained by further laminating a brightness enhancement film on a polarizing plate is preferable.
[0066]
The reflection type polarizing plate is provided with a reflection layer on a polarizing plate, and is used to form a liquid crystal display device of a type that reflects incident light from a viewing side (display side) and displays the reflected light. There is an advantage that the built-in light source can be omitted, and the liquid crystal display device can be easily made thinner. The reflective polarizing plate can be formed by an appropriate method such as a method in which a reflective layer made of metal or the like is provided on one surface of the polarizing plate via a transparent protective layer or the like as necessary.
[0067]
Specific examples of the reflective polarizing plate include those in which a reflective layer formed by attaching a foil or a vapor-deposited film made of a reflective metal such as aluminum to one surface of a transparent protective film that has been matted as necessary. Further, there may be mentioned, for example, a transparent protective film in which fine particles are contained to form a fine surface unevenness structure, and a reflective layer having a fine unevenness structure is formed thereon. The reflective layer having the above-mentioned fine uneven structure has an advantage of diffusing incident light by irregular reflection, preventing directivity and glare, and suppressing unevenness in brightness and darkness. Further, the transparent protective film containing fine particles also has an advantage that the incident light and the reflected light thereof are diffused when transmitting the light, and thus the unevenness of brightness and darkness can be further suppressed. The reflection layer having a fine uneven structure reflecting the fine uneven structure on the surface of the transparent protective film can be formed by, for example, making the metal transparent by an appropriate method such as an evaporation method such as a vacuum evaporation method, an ion plating method, or a sputtering method, or a plating method. It can be carried out by a method of directly attaching to the surface of the protective layer.
[0068]
The reflection plate can be used as a reflection sheet or the like in which a reflection layer is provided on an appropriate film according to the transparent film instead of the method of directly applying the reflection plate to the transparent protective film. Since the reflective layer is usually made of a metal, the use form in which the reflective surface is covered with a transparent protective film, a polarizing plate, or the like is intended to prevent a decrease in the reflectance due to oxidation and, as a result, a long-lasting initial reflectance. It is more preferable to avoid separately providing a protective layer.
[0069]
The transflective polarizing plate can be obtained by forming a transflective reflective layer such as a half mirror that reflects and transmits light with the reflective layer. A transflective polarizing plate is usually provided on the back side of a liquid crystal cell. When a liquid crystal display device or the like is used in a relatively bright atmosphere, an image is displayed by reflecting incident light from the viewing side (display side). In a relatively dark atmosphere, a liquid crystal display device of a type that displays an image using a built-in light source such as a backlight built in the back side of a transflective polarizing plate can be formed. That is, the transflective polarizing plate can save energy for use of a light source such as a backlight in a bright atmosphere, and is useful for forming a liquid crystal display device of a type that can be used with a built-in light source even in a relatively dark atmosphere. It is.
[0070]
An elliptically polarizing plate or a circularly polarizing plate in which a retardation plate is further laminated on a polarizing plate will be described. When changing linearly polarized light to elliptically or circularly polarized light, changing elliptically or circularly polarized light to linearly polarized light, or changing the polarization direction of linearly polarized light, a phase difference plate or the like is used. In particular, a so-called quarter-wave plate (also referred to as a λ / 4 plate) is used as a retardation plate that converts linearly polarized light into circularly polarized light or converts circularly polarized light into linearly polarized light. A half-wave plate (also referred to as a λ / 2 plate) is usually used to change the polarization direction of linearly polarized light.
[0071]
The elliptically polarizing plate compensates (prevents) coloring (blue or yellow) caused by the birefringence of the liquid crystal layer of a super twisted nematic (STN) type liquid crystal display device, and is effectively used for a black-and-white display without the coloring. Can be Further, the one in which the three-dimensional refractive index is controlled is preferable because coloring which occurs when the screen of the liquid crystal display device is viewed from an oblique direction can be compensated (prevented). The circularly polarizing plate is effectively used, for example, when adjusting the color tone of an image of a reflection type liquid crystal display device that displays an image in color, and also has an antireflection function.
[0072]
Examples of the retardation plate include a birefringent film obtained by uniaxially or biaxially stretching a polymer material, an alignment film of a liquid crystal polymer, and an alignment layer of a liquid crystal polymer supported by a film. Although the thickness of the retardation plate is not particularly limited, it is generally about 20 to 150 μm.
[0073]
As a polymer material, for example, polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, Polyphenylene sulfide, polyphenylene oxide, polyallyl sulfone, polyvinyl alcohol, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose polymer, norbornene resin, or binary, ternary copolymers, graft copolymers of these Examples include polymers and blends. These polymer materials become oriented products (stretched films) by stretching or the like.
[0074]
Examples of the liquid crystalline polymer include various types of main chain and side chain in which a conjugated linear atomic group (mesogen) imparting liquid crystal orientation is introduced into the main chain and side chain of the polymer. Can be Specific examples of the main chain type liquid crystal polymer include a structure in which a mesogen group is bonded with a spacer portion that imparts flexibility, such as a nematic-aligned polyester-based liquid crystal polymer, a discotic polymer, and a cholesteric polymer. . Specific examples of the side chain type liquid crystalline polymer include polysiloxane, polyacrylate, polymethacrylate, or polymalonate as a main chain skeleton, and a paraffin imparting nematic alignment through a spacer portion composed of a conjugate atomic group as a side chain. And those having a mesogen moiety composed of a substituted cyclic compound unit. These liquid crystalline polymers are prepared, for example, by rubbing the surface of a thin film of polyimide or polyvinyl alcohol formed on a glass plate, or by applying a liquid crystalline polymer solution on an alignment-treated surface such as obliquely deposited silicon oxide. It is performed by developing and heat-treating.
[0075]
The retardation plate may have an appropriate retardation depending on the purpose of use, such as, for example, a color plate due to birefringence of various wave plates or a liquid crystal layer, or a target for compensation of a viewing angle or the like. A retardation plate may be laminated to control optical characteristics such as retardation.
[0076]
Further, the elliptically polarizing plate or the reflection type elliptically polarizing plate is obtained by laminating a polarizing plate or a reflection type polarizing plate and a retardation plate in an appropriate combination. Such an elliptically polarizing plate or the like can also be formed by sequentially and separately laminating a (reflection type) polarizing plate and a retardation plate in the manufacturing process of a liquid crystal display device so as to form a combination. An optical member such as a polarizing plate has an advantage that it is excellent in quality stability and laminating workability, and can improve the production efficiency of a liquid crystal display device and the like.
[0077]
The viewing angle compensation film is a film for widening the viewing angle so that an image can be seen relatively clearly even when the screen of the liquid crystal display device is viewed not in a direction perpendicular to the screen but in a slightly oblique direction. Such a viewing angle compensating retardation plate includes, for example, a retardation plate, an alignment film such as a liquid crystal polymer, and a transparent substrate on which an alignment layer such as a liquid crystal polymer is supported. The ordinary retardation plate is a polymer film having birefringence uniaxially stretched in the plane direction, whereas the retardation plate used as the viewing angle compensation film is biaxially stretched in the plane direction. A birefringent polymer film such as a polymer film having birefringence or a birefringent polymer such as a birefringent polymer and a birefringent polymer in which the refractive index in the thickness direction is stretched uniaxially in the plane direction and also stretched in the thickness direction and controlled in the thickness direction. Used. Examples of the obliquely oriented film include a film obtained by bonding a heat shrinkable film to a polymer film and subjecting the polymer film to a stretching treatment and / or shrinkage treatment under the action of the shrinkage force caused by heating, and a film obtained by obliquely aligning a liquid crystal polymer. No. As the raw material polymer of the retardation plate, the same polymer as described in the above retardation plate is used to prevent coloring or the like due to a change in the viewing angle based on the phase difference due to the liquid crystal cell and to enlarge the viewing angle for good visibility. Any appropriate one for the purpose can be used.
[0078]
In addition, because of achieving a wide viewing angle with good visibility, the optically-compensated retardation, in which an optically anisotropic layer consisting of an alignment layer of liquid crystal polymer, particularly a tilted alignment layer of discotic liquid crystal polymer, is supported by a triacetyl cellulose film A plate can be preferably used.
[0079]
A polarizing plate obtained by laminating a polarizing plate and a brightness enhancement film is usually used by being provided on the back side of a liquid crystal cell. The brightness enhancement film reflects linearly polarized light of a predetermined polarization axis or circularly polarized light of a predetermined direction when natural light is incident due to reflection from a backlight or a back side of a liquid crystal display device, and has a property of transmitting other light. A polarizing plate obtained by laminating a brightness enhancement film and a polarizing plate, while transmitting light from a light source such as a backlight to obtain a transmission light in a predetermined polarization state, is reflected without transmitting light other than the predetermined polarization state. You. The light reflected on the surface of the brightness enhancement film is further inverted through a reflection layer or the like provided on the rear side thereof and re-incident on the brightness enhancement film, and a part or all of the light is transmitted as light of a predetermined polarization state to thereby obtain brightness. In addition to increasing the amount of light transmitted through the enhancement film, it is also possible to improve the luminance by supplying polarized light that is hardly absorbed by the polarizer to increase the amount of light that can be used for liquid crystal display image display and the like. In other words, when light is incident through the polarizer from the back side of the liquid crystal cell with a backlight or the like without using a brightness enhancement film, light having a polarization direction that does not match the polarization axis of the polarizer is almost completely polarized. Is absorbed by the polarizer and does not pass through the polarizer. That is, although it depends on the characteristics of the polarizer used, about 50% of the light is absorbed by the polarizer, and accordingly, the amount of light available for liquid crystal image display and the like decreases, and the image becomes darker. The brightness enhancement film is such that light having a polarization direction as absorbed by the polarizer is once reflected by the brightness enhancement film without being incident on the polarizer, and further inverted through a reflection layer or the like provided behind the same. The brightness enhancement film transmits only the polarized light whose polarization direction has been changed so that the polarization direction of the light reflected and inverted between the two can pass through the polarizer. Since light is supplied to the polarizer, light from a backlight or the like can be efficiently used for displaying an image on the liquid crystal display device, and the screen can be brightened.
[0080]
A diffusion plate may be provided between the brightness enhancement film and the above-mentioned reflection layer or the like. The light in the polarization state reflected by the brightness enhancement film goes to the reflection layer and the like, but the diffuser provided uniformly diffuses the light passing therethrough, and at the same time, eliminates the polarization state and becomes a non-polarization state. That is, the diffuser returns the polarized light to the original natural light state. The light in the non-polarized state, that is, the light in the natural light state is repeatedly directed to the reflection layer and the like, reflected through the reflection layer and the like, again passed through the diffusion plate and re-incident on the brightness enhancement film. Thus, while maintaining the brightness of the display screen by providing a diffusion plate that returns polarized light to the original natural light state between the brightness enhancement film and the reflective layer, etc., at the same time, reducing unevenness in the brightness of the display screen, A uniform and bright screen can be provided. It is considered that by providing such a diffusion plate, the number of repetitions of the reflection of the first incident light is moderately increased, and a uniform bright display screen can be provided in combination with the diffusion function of the diffusion plate.
[0081]
The brightness enhancement film has a property of transmitting linearly polarized light having a predetermined polarization axis and reflecting other light, such as a multilayer thin film of a dielectric or a multilayer laminate of thin films having different refractive index anisotropies. As shown in the figure, such as a cholesteric liquid crystal polymer oriented film or a film in which the oriented liquid crystal layer is supported on a film substrate, it exhibits a property of reflecting either left-handed or right-handed circularly polarized light and transmitting other light. Any suitable one such as one can be used.
[0082]
Therefore, in the brightness enhancement film of the type that transmits linearly polarized light having the predetermined polarization axis, the transmitted light is incident on the polarization plate as it is, with the polarization axis aligned, thereby efficiently transmitting the light while suppressing the absorption loss by the polarization plate. Can be done. On the other hand, in a brightness enhancement film of the type that emits circularly polarized light, such as a cholesteric liquid crystal layer, it can be directly incident on a polarizer, but from the viewpoint of suppressing absorption loss, the circularly polarized light is linearly polarized through a retardation plate. It is preferable that the light is incident on a polarizing plate. By using a quarter-wave plate as the retardation plate, circularly polarized light can be converted to linearly polarized light.
[0083]
A retardation plate that functions as a quarter-wave plate in a wide wavelength range such as a visible light region exhibits, for example, a retardation layer that functions as a quarter-wave plate for light-color light having a wavelength of 550 nm and other retardation characteristics. It can be obtained by a method of superimposing a retardation layer, for example, a retardation layer functioning as a half-wave plate. Therefore, the retardation plate disposed between the polarizing plate and the brightness enhancement film may be composed of one or more retardation layers.
[0084]
The cholesteric liquid crystal layer is also configured such that two or three or more cholesteric liquid crystal layers are superimposed on each other to reflect circularly polarized light in a wide wavelength range such as a visible light region. Based on this, it is possible to obtain circularly polarized light transmitted in a wide wavelength range.
[0085]
Further, the polarizing plate may be formed by laminating a polarizing plate and two or three or more optical layers as in the above-mentioned polarized light separating type polarizing plate. Therefore, a reflective elliptically polarizing plate or a transflective elliptically polarizing plate obtained by combining the above-mentioned reflective polarizing plate, semi-transmissive polarizing plate, and retardation plate may be used.
[0086]
The optical member obtained by laminating the optical layer on a polarizing plate can be formed by a method of sequentially laminating the optical member in a manufacturing process of a liquid crystal display device or the like. It has the advantage of being excellent in stability and assembling work, and can improve a manufacturing process of a liquid crystal display device or the like. Appropriate bonding means such as an adhesive layer can be used for lamination. When bonding the above-mentioned polarizing plate and other optical layers, their optical axes can have an appropriate arrangement angle according to the target retardation characteristics and the like.
[0087]
The pressure-sensitive adhesive layer (2) is laminated on the optical member (1) via the functional group-containing polymer layer (3a) and the functional group-containing polymer layer (3b) irradiated with ultraviolet rays. There is no particular limitation.
[0088]
For example, a functional group-containing polymer layer (3a) is formed on at least one surface of the optical member (1). On the other hand, the pressure-sensitive adhesive layer (2) is formed on the release-treated substrate (4), and the functional group-containing polymer layer (3a) is further formed. Next, one of the functional group-containing polymer layers (3a) is irradiated with ultraviolet light to form a functional group-containing polymer layer (3b) irradiated with ultraviolet light. Next, the functional group-containing polymer layer (3a) that has not been irradiated with ultraviolet rays and the functional group-containing polymer layer (3b) that has been irradiated with ultraviolet rays are bonded to each other to obtain the optical member with a pressure-sensitive adhesive of the present invention. FIG. 2 shows an example in which the functional group-containing polymer layer (3a) formed on the side of the pressure-sensitive adhesive layer (2) is replaced with a functional group-containing polymer layer (3b) irradiated with ultraviolet rays. In the example of FIG. 2, the optical member with an adhesive shown in FIG. 1 is obtained.
[0089]
The method for forming the functional group-containing polymer layer (3a) and the pressure-sensitive adhesive layer (2) is not particularly limited, but can be formed, for example, by coating. As a coating method, any coating method such as a roll coater such as a reverse coater and a gravure coater, a curtain coater, a lip coater, and a die coater can be adopted. Further, the formation of each layer can be performed by utilizing a method of transferring what is formed on the release-treated substrate (4).
[0090]
In addition, as a lamination method other than the above, for example, from the optical member (1) side, a functional group-containing polymer layer (3a), a functional group-containing polymer layer (3b) irradiated with ultraviolet rays, and then an adhesive layer ( 2) may be laminated. After forming the pressure-sensitive adhesive layer (2) on the release-treated base material (4), the functional group-containing polymer layer (3a) and the functional group-containing polymer layer (3b) irradiated with ultraviolet light were formed into an optically It may be bonded to the member (1).
[0091]
The thickness of the pressure-sensitive adhesive layer (2) (dry film thickness) is not particularly limited, but is preferably 2 to 500 μm, and more preferably about 5 to 100 μm.
[0092]
The thickness (dry film thickness) of the functional group-containing polymer layer (3a) and the functional group-containing polymer layer (3b) irradiated with ultraviolet light is not particularly limited, but is preferably about 0.02 to 0.2 μm. Preferably it is 0.03-0.15 μm. The total thickness (dry film thickness) of the functional group-containing polymer layer (3a) and the functional group-containing polymer layer (3b) irradiated with ultraviolet rays is preferably about 0.04 to 0.4 μm, and more preferably 0.1 to 0.4 μm. 05 to 0.3 μm. The thickness (dry film thickness) of the functional group-containing polymer layer (3a) and the functional group-containing polymer layer (3b) irradiated with ultraviolet rays may be the same or different as long as it is within the above range. If the total thickness (dry film thickness) is less than 0.04 μm, it is difficult to apply uniformly, and defects may occur. On the other hand, if the total thickness exceeds 0.4 μm, cohesive failure occurs in the functional group-containing polymer layer. May be undesirable.
[0093]
In forming the functional group-containing polymer layer (3a), the optical member (1) and the pressure-sensitive adhesive layer (2) can be subjected to an activation treatment. By performing the activation treatment, cissing at the time of forming the functional group-containing polymer layer (3a) or the like can be suppressed. Further, the functional group-containing polymer layer (3a) and the like can be formed with good adhesion. For the activation treatment, various methods can be adopted, for example, a corona treatment, a low-pressure UV treatment, a plasma treatment and the like can be adopted.
[0094]
Examples of the constituent material of the release-treated base material (4) include paper, synthetic resin films such as polyethylene, polypropylene, and polyethylene terephthalate, rubber sheets, paper, cloth, nonwoven fabrics, nets, foam sheets, metal foils, and laminates thereof. Suitable thin leaf bodies and the like can be mentioned. The surface of the release-treated substrate (4) may be subjected to a release treatment such as a silicone treatment, a long-chain alkyl treatment, a fluorine treatment, or the like, as necessary, in order to enhance the releasability from the pressure-sensitive adhesive layer (2). good.
[0095]
In addition, each layer such as the optical member and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive optical member of the present invention includes, for example, an ultraviolet ray such as a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate compound, and a nickel complex compound. It may have ultraviolet absorbing ability by a method such as a treatment with an absorbent.
[0096]
The adhesive optical member of the present invention can be preferably used for forming various image display devices such as a liquid crystal display device. The formation of the liquid crystal display device can be performed according to a 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 member, and an illumination system as necessary, and incorporating a drive circuit. There is no particular limitation except that an optical member according to (1) is used. As for the liquid crystal cell, any type such as TN type, STN type and π type can be used.
[0097]
Appropriate liquid crystal display devices such as a liquid crystal display device in which an adhesive optical member is arranged on one or both sides of a liquid crystal cell, and a lighting system using a backlight or a reflector can be formed. In that case, the optical member according to the present invention can be installed on one side or both sides of the liquid crystal cell. When optical members are provided on both sides, they may be the same or different. Further, when forming the liquid crystal display device, for example, a suitable component such as a diffusion plate, an anti-glare layer, an antireflection film, a protection plate, a prism array, a lens array sheet, a light diffusion plate, a backlight, etc. Two or more layers can be arranged.
[0098]
Next, an organic electroluminescence device (organic EL display device) will be described. In general, in an organic EL display device, a luminous body (organic electroluminescent luminous body) is formed by sequentially laminating a transparent electrode, an organic luminescent layer, and a metal electrode on a transparent substrate. Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like, and a light emitting layer made of a fluorescent organic solid such as anthracene, Alternatively, a configuration having various combinations such as a stacked body of such a light emitting layer and an electron injection layer made of a perylene derivative, or a stacked body of a hole injection layer, a light emitting layer, and an electron injection layer thereof is known. Have been.
[0099]
In an organic EL display device, holes and electrons are injected into an organic light emitting layer by applying a voltage to a transparent electrode and a metal electrode, and energy generated by recombination of these holes and electrons excites a fluorescent substance. Then, light is emitted on the principle that the excited fluorescent substance emits light when returning to the ground state. The mechanism of recombination on the way is the same as that of a general diode, and as can be expected from this, the current and the emission intensity show strong nonlinearity accompanied by rectification with respect to the applied voltage.
[0100]
In an organic EL display device, at least one of the electrodes must be transparent in order to extract light emitted from the organic light emitting layer. Usually, a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO) is used as an anode. Used as On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a material having a small work function for the cathode, and usually a metal electrode such as Mg-Ag or Al-Li is used.
[0101]
In the organic EL display device having such a configuration, the organic light emitting layer is formed of an extremely thin film having a thickness of about 10 nm. Therefore, the organic light emitting layer transmits light almost completely, similarly to the transparent electrode. As a result, when light is incident from the surface of the transparent substrate during non-light emission, light transmitted through the transparent electrode and the organic light-emitting layer and reflected by the metal electrode again exits to the surface side of the transparent substrate, and when viewed from the outside, The display surface of the organic EL display device looks like a mirror surface.
[0102]
In an organic EL display device including an organic electroluminescent luminous body having a transparent electrode on the front side of an organic luminescent layer that emits light by applying a voltage and a metal electrode on the back side of the organic luminescent layer, the surface of the transparent electrode A polarizing plate can be provided on the side, and a retardation plate can be provided between the transparent electrode and the polarizing plate.
[0103]
Since the retardation plate and the polarizing plate have a function of polarizing light incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarizing function. In particular, if the retardation plate is formed of a 1/4 wavelength plate and the angle between the polarization directions of the polarizing plate and the retardation plate is adjusted to π / 4, the mirror surface of the metal electrode can be completely shielded. .
[0104]
That is, as for the external light incident on the organic EL display device, only the linearly polarized light component is transmitted by the polarizing plate. This linearly polarized light is generally converted into elliptically polarized light by the phase difference plate, but becomes circularly polarized light particularly when the phase difference plate is a １ wavelength plate and the angle between the polarization directions of the polarizing plate and the phase difference plate is π / 4. .
[0105]
This circularly polarized light transmits through the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, passes through the organic thin film, the transparent electrode, and the transparent substrate again, and becomes linearly polarized light again by the phase difference plate. The linearly polarized light cannot pass through the polarizing plate because it is orthogonal to the polarizing direction of the polarizing plate. As a result, the mirror surface of the metal electrode can be completely shielded.
[0106]
【Example】
Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. In addition, all parts and% in each example are based on weight.
[0107]
Example 1
(Preparation of acrylic adhesive)
90 parts of butyl acrylate, 10 parts of ethyl acrylate, 1 part of acrylic acid, 0.1 part of 2-hydroxyethyl acrylate, 0.1 part of 2,2-azobisisobutyronitrile and 200 parts of ethyl acetate were introduced into a nitrogen introducing tube. Into a four-necked flask equipped with a cooling tube, and after sufficiently purging with nitrogen, perform a polymerization reaction at 55 ° C. for 12 hours while stirring under a nitrogen stream to obtain a solution of an acrylic polymer having a weight average molecular weight of 850,000. Obtained. 0.1 part of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent and tolylene diisocyanate adduct of trimethylolpropane as a crosslinking agent with respect to 100 parts of the acrylic polymer solution (solid content) Of a polyisocyanate-based cross-linking agent consisting of the same was uniformly mixed to prepare a pressure-sensitive adhesive composition.
[0108]
(Formation of pressure-sensitive adhesive layer (2))
The above-mentioned pressure-sensitive adhesive composition is applied to a 38 μm-thick polyethylene terephthalate film subjected to a silicone release treatment so that the dry thickness of the pressure-sensitive adhesive layer is 25 μm, and dried and crosslinked at 110 ° C. for 5 minutes to perform pressure-sensitive adhesive layer ( 2) was formed. The solvent-insoluble content of the pressure-sensitive adhesive layer (2) was 63% by weight.
[0109]
(Formation of functional group-containing polymer layer (3b))
On a surface of the pressure-sensitive adhesive layer (2), a 1% aqueous solution of polyethyleneimine (number average molecular weight 69000 measured by a viscosity method) was applied with a wire bar No. 9 and dried at 90 ° C. for 1 minute to form a functional group-containing polymer layer (3a) having a thickness of 0.11 μm. Next, the surface of the functional group-containing polymer layer (3a) was exposed to UV-C light of 120 mJ / cm using a high-pressure mercury lamp using a UV power pack (manufactured by Fusion UV Systems Japan, Ltd.). ² Was irradiated to obtain a functional group-containing polymer layer (3b).
[0110]
(Formation of functional group-containing polymer layer (3a))
A polyvinyl alcohol film having a thickness of 80 μm was stretched 5 times in an aqueous iodine solution at 40 ° C., and then dried at 50 ° C. for 4 minutes to obtain a polarizer. A triacetyl cellulose film was bonded to both sides of the polarizer using a polyvinyl alcohol-based adhesive to obtain a polarizing plate. A 0.5% aqueous solution of polyethyleneimine (number average molecular weight 69000 as measured by a viscosity method) was applied to one surface of a polarizing plate using a wire bar No. 9 and dried at 90 ° C. for 1 minute to form a functional group-containing polymer layer (3a) having a thickness of 0.05 μm.
[0111]
(Preparation of optical member with adhesive)
The functional group-containing polymer layer (3b) formed on the surface of the pressure-sensitive adhesive layer (2) and irradiated with ultraviolet light is bonded to the functional group-containing polymer layer (3a) formed on the surface of the polarizing plate. An optical member with an adhesive was produced.
[0112]
Example 2
(Preparation of acrylic adhesive)
A monomer mixture of 70 parts of butyl acrylate, 27 parts of 2-ethylhexyl acrylate, and 3 parts of acrylic acid was emulsified in 122 parts of water using 3 parts of polyoxyethylene distyrenated phenyl ether ammonium sulfate as an emulsifier. Using 0.05 parts of azobis (2-amidinopropane) dihydrochloride, a polymerization reaction was carried out at 50 ° C. for 3 hours and further at 65 ° C. for 2 hours. Further, an aqueous dispersion of an acrylic polymer whose viscosity was adjusted with aqueous ammonia was obtained. To 100 parts of an aqueous dispersion (solid content) of an acrylic polymer, 0.1 part of 3-glycidoxypropyltrimethoxysilane was uniformly mixed as a silane coupling agent to prepare a pressure-sensitive adhesive composition.
[0113]
(Formation of pressure-sensitive adhesive layer (2))
The above-mentioned pressure-sensitive adhesive composition was applied to a 38 μm-thick polyethylene terephthalate film subjected to a silicone release treatment so that the dry thickness of the pressure-sensitive adhesive layer was 25 μm, and dried and crosslinked at 100 ° C. for 5 minutes to perform pressure-sensitive adhesive layer ( 2) was formed. The solvent-insoluble content of the pressure-sensitive adhesive layer (2) was 68% by weight.
[0114]
(Formation of functional group-containing polymer layer (3b))
On a surface of the pressure-sensitive adhesive layer (2), a 1% aqueous solution of polyethyleneimine (number average molecular weight 69000 measured by a viscosity method) was applied with a wire bar No. 9 and dried for 1 minute at 90 ° C. to form a functional group-containing polymer layer (3a) having a thickness of 0.05 μm. Next, the surface of the functional group-containing polymer layer (3a) was exposed to high-pressure mercury lamp with a UV-C light of 200 mJ / cm from UV Power Pack (manufactured by Fusion UV Systems Japan). ² Was irradiated to obtain a functional group-containing polymer layer (3b).
[0115]
(Formation of functional group-containing polymer layer (3a))
A polyvinyl alcohol film having a thickness of 80 μm was stretched 5 times in an aqueous iodine solution at 40 ° C., and then dried at 50 ° C. for 4 minutes to obtain a polarizer. A triacetyl cellulose film was bonded to both sides of the polarizer using a polyvinyl alcohol-based adhesive to obtain a polarizing plate. A 0.5% aqueous solution of polyethyleneimine (number average molecular weight 69000 as measured by a viscosity method) was applied to one surface of a polarizing plate using a wire bar No. 9 and dried at 90 ° C. for 1 minute to form a functional group-containing polymer layer (3a) having a thickness of 0.05 μm.
[0116]
(Preparation of optical member with adhesive)
The functional group-containing polymer layer (3b) formed on the surface of the pressure-sensitive adhesive layer (2) and irradiated with ultraviolet light is bonded to the functional group-containing polymer layer (3a) formed on the surface of the polarizing plate. An optical member with an adhesive was produced.
[0117]
Example 3
In Example 1, the functional group-containing polymer layer (3a) formed on the surface of the pressure-sensitive adhesive layer (2) was used without being irradiated with ultraviolet light, while the functional group-containing polymer layer (3a) formed on one surface of the polarizing plate was used. The surface of 3a) was exposed with a high-pressure mercury lamp and the UV-C light quantity of U-V Powerpack (manufactured by Fusion UV Systems Japan KK) was 120 mJ / cm. ² An optical member with a pressure-sensitive adhesive was produced in the same manner as in Example 1 except that the ultraviolet ray was irradiated to obtain a functional group-containing polymer layer (3b).
[0118]
Comparative Example 1
In Example 1, an optical member with an adhesive was prepared in the same manner as in Example 1 except that the functional group-containing polymer layer (3a) was not formed on the surface of the adhesive layer (2) and no ultraviolet irradiation was performed. Produced.
[0119]
Comparative Example 2
An optical member with a pressure-sensitive adhesive was produced in the same manner as in Example 1, except that the functional group-containing polymer layer (3a) was not formed on one surface of the polarizing plate.
[0120]
Comparative Example 3
In Example 1, the functional group-containing polymer layer (3a) was not formed on the surface of the pressure-sensitive adhesive layer (2), and no ultraviolet irradiation was performed. Further, the functional group-containing polymer layer (3a) was formed on one surface of the polarizing plate. An optical member with a pressure-sensitive adhesive was produced in the same manner as in Example 1, except that the optical member was not formed.
[0121]
Comparative Example 4
Optical member with an adhesive in the same manner as in Example 1 except that the functional group-containing polymer layer (3a) formed on the surface of the adhesive layer (2) was used as it was without irradiation with ultraviolet rays. Was prepared.
[0122]
The following evaluations were performed on the pressure-sensitive adhesive optical members obtained in the above Examples and Comparative Examples. Table 1 shows the evaluation results.
[0123]
(Adhesion (1))
A sample obtained by cutting the adhesive optical member into a size of 25 mm × 60 mm was attached to a non-alkali glass plate (Corning 1737, manufactured by Corning Incorporated) and autoclaved at 50 ° C. and a pressure of 0.5 MPa for 30 minutes. Thereafter, the mixture was stored at 90 ° C. for 200 hours and then returned to room temperature. Thereafter, 90 ° peeling was performed at a pulling speed of 1000 mm / min. At this time, the state of adhesion of the pressure-sensitive adhesive to the glass plate was confirmed and evaluated according to the following criteria.
：: No adhesive was left at all.
Δ: Less than 50%, but some adhesive remained.
X: 50% or more of the adhesive remained.
[0124]
(Adhesion (2))
One side of a double-sided tape (Nitto Denko Corporation, No. 500) is attached to the adhesive layer of the adhesive optical member, and the other side of the double-sided tape is attached to a SUS plate, and then left at 100 ° C. for 17 hours. Thereafter, 90 ° peeling was performed at room temperature (23 ° C.) at a tensile speed of 300 mm / min. At this time, the remaining state of the pressure-sensitive adhesive on the optical member was confirmed and evaluated according to the following criteria.
：: The adhesive was not peeled at all.
Δ: Less than 50%, but part of the adhesive was peeled off.
×: The adhesive was peeled off by 50% or more.
[0125]
[Table 1]

In Table 1, as shown in the adhesion (1), it can be seen that the pressure-sensitive adhesive optical member of the present invention can be peeled without adhesive residue and has excellent re-peelability. Further, as shown in the adhesion (2), it can be seen that the adhesion between the optical member and the pressure-sensitive adhesive layer is larger than the adhesion to the double-sided tape. From now on, it is recognized that the durability is good even under a condition where severe conditions are required, and that peeling and floating between the optical member and the pressure-sensitive adhesive layer can be suppressed.
[Brief description of the drawings]
FIG. 1 is an example of a sectional view of an optical member with a pressure-sensitive adhesive of the present invention.
FIG. 2 is a cross-sectional view illustrating an example of a method for manufacturing an optical member with a pressure-sensitive adhesive according to the present invention.
[Explanation of symbols]
1 Optical member
2 Adhesive layer
3a Functional group-containing polymer layer
3b UV-irradiated functional group-containing polymer layer
4 Release treated substrate

Claims (9)

An optical member with an adhesive in which an adhesive layer (2) is laminated on at least one surface of the optical member (1),
The optical member with a pressure-sensitive adhesive, wherein the pressure-sensitive adhesive layer (2) is laminated via a functional group-containing polymer layer (3a) and a functional group-containing polymer layer (3b) irradiated with ultraviolet rays. From the optical member (1) side, a functional group-containing polymer layer (3a), a functional group-containing polymer layer (3b) irradiated with ultraviolet rays are sequentially laminated, and then an adhesive layer (2) is laminated. The optical member with a pressure-sensitive adhesive according to claim 1. The functional group-containing polymer used for forming the functional group-containing polymer layer (3a) and the functional group-containing polymer layer (3b) irradiated with ultraviolet rays is an amino group-containing polymer. Optical member with adhesive. The optical member with a pressure-sensitive adhesive according to claim 3, wherein the amino group-containing polymer is a polyethyleneimine-based polymer. The total thickness of the functional group-containing polymer layer (3a) and the thickness of the functional group-containing polymer layer (3b) irradiated with ultraviolet rays is 0.04 to 0.4 μm. An optical member with a pressure-sensitive adhesive according to any one of the above. The optical member with an adhesive according to any one of claims 1 to 5, wherein the adhesive layer (2) is formed of an acrylic adhesive. The acrylic pressure-sensitive adhesive contains 0.01 to 1 part by weight of a silane coupling agent with respect to 100 parts by weight of the acrylic polymer, and the pressure-sensitive adhesive layer (2) has a solvent-insoluble content of 30 to 100 parts by weight. The optical member with a pressure-sensitive adhesive according to claim 6, wherein the content is 90% by weight. Forming a functional group-containing polymer layer (3a) on at least one surface of the optical member (1);
Forming a pressure-sensitive adhesive layer (2) on the release-treated substrate (4) and then forming a functional group-containing polymer layer (3a);
Irradiating one of the functional group-containing polymer layers (3a) with ultraviolet light to form a functional group-containing polymer layer (3b) irradiated with ultraviolet light; and ) And a step of bonding the functional group-containing polymer layer (3b) irradiated with ultraviolet light;
The method for producing an optical member with a pressure-sensitive adhesive according to any one of claims 1 to 7, comprising: An image display device using at least one optical member with a pressure-sensitive adhesive according to claim 1.

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