CN115718342A - Polarizing film with optical function layer and liquid crystal display device - Google Patents

Abstract

The present invention provides a polarizing film with an optical functional layer, which comprises an optical functional layer (A) containing a pigment and a polyvinyl alcohol polarizer (P), wherein the distance (x) between the optical functional layer (A) and the polyvinyl alcohol polarizer (P) is less than 45 [ mu ] m. The polarizing film with an optical functional layer of the present invention has good stability over time, and has an optical functional layer containing a pigment capable of maintaining a wide color range by the pigment.

Description

Polarizing film with optical functional layer and liquid crystal display device

The present application is a divisional application of an application having an application date of 2018, 3 and 5, and an application number of 201880011269.6, entitled "polarizing film with optical functional layer and liquid crystal display device".

Technical Field

The present invention relates to a polarizing film with an optical functional layer, which has an optical functional layer with a pigment and a polarizing film with a polyvinyl alcohol polarizer. The polarizing film with an optically functional layer may be used alone or in the form of an optical film in which the polarizing film with an optically functional layer is laminated to form an image display device such as a Liquid Crystal Display (LCD) or an organic EL display.

Background

In an image display device or the like, it is essential to dispose polarizing elements on both sides of a liquid crystal cell in view of an image forming method, and a polarizing film is generally bonded thereto. When the polarizing film is attached to the liquid crystal cell, an adhesive is generally used. In order to reduce the loss of light, the polarizing film and the liquid crystal cell are generally adhered to each other by using an adhesive. In this case, since there is an advantage that a drying process for fixing the polarizing film is not required, a polarizing film with a pressure-sensitive adhesive layer is generally used in which a pressure-sensitive adhesive is provided as a pressure-sensitive adhesive layer on one surface of the polarizing film in advance.

In addition, a liquid crystal display having a high contrast ratio has been proposed in which a dye or a pigment is added to the pressure-sensitive adhesive layer to impart an arbitrary color tone to a polarizing film for coloring (patent document 1). In recent years, image display devices are required to have brightness and vividness (i.e., to have a wide color gamut), organic EL display devices (OLEDs) are attracting attention, and liquid crystal display devices are also required to have a wide color gamut. For example, as a method for widening the color gamut of a liquid crystal display device, it has been proposed to laminate a polarizing film on one surface or both surfaces of the liquid crystal cell with an adhesive layer containing a dye exhibiting an absorption maximum wavelength in a specific wavelength range (560 to 610 nm) (patent documents 2 and 3).

Documents of the prior art

Patent literature

Patent document 1: japanese Uygur Specification No. 3052812

Patent document 2: japanese patent laid-open publication No. 2011-039093

Patent document 3: japanese patent laid-open publication No. 2014-092611

Disclosure of Invention

Problems to be solved by the invention

In addition to the pigment contained in the pressure-sensitive adhesive layer as described above, the pigment may be contained in a film layer applied to the optical member. In this way, by including a coloring matter in a resin layer such as a film layer or a pressure-sensitive adhesive layer, an optical functional layer containing a coloring matter can be formed. However, since the optical functional layer contains a coloring matter, the coloring matter in the optical functional layer deteriorates with time and the optical functional layer gradually discolors from the viewpoint of moisture permeability of the resin layer which is a base of the optical functional layer. In particular, when the optical functional layer is a binder layer containing a pigment, the binder layer is insufficient in durability from the viewpoint of moisture permeability, and the binder layer that has been colored with the pigment at first also gradually fades. As described above, when the dye in the optical functional layer (particularly, the pressure-sensitive adhesive layer) deteriorates with time, it is difficult to maintain the wide color gamut obtained by the dye.

The purpose of the present invention is to provide an optically functional polarizing film having an optically functional layer containing a pigment, which has good stability over time and can maintain a wide color range achieved by the pigment.

Means for solving the problems

The present inventors have made extensive studies to solve the above problems, and as a result, have found the following polarizing film with an adhesive layer, and have completed the present invention.

That is, the present invention relates to a polarizing film with an optical functional layer, which has an optical functional layer containing a pigment on at least one side of a polarizing film having a polyvinyl alcohol-based polarizer, wherein a distance between the polyvinyl alcohol-based polarizer and the optical functional layer containing the pigment is 45 μm or less. The distance between the polyvinyl alcohol polarizer and the optical function layer is preferably 25 μm or less.

The polarizing film with an optically functional layer may be formed by directly laminating the polyvinyl alcohol polarizer and the adhesive layer.

In the polarizing film with an optically functional layer, at least 1 layer having a thickness of 45 μm or less and having no coloring matter may be provided between the polyvinyl alcohol based polarizer and the pressure-sensitive adhesive layer.

In the polarizing film with an optically functional layer, the polyvinyl alcohol polarizer preferably has an oxygen transmittance of 1[ cm ]) ³ /(m ² ·24h·atm)]The following.

In the polarizing film with an optically functional layer, the dye may have a maximum absorption wavelength in at least one of a wavelength range of 470 to 510nm and a wavelength range of 570 to 610 nm.

In the polarizing film with an optically functional layer, a porphyrazine-based dye may be used as the dye.

In the polarizing film with an optically functional layer, the coloring matter is preferably contained in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the base polymer of the resin layer forming the optically functional layer.

In the polarizing film with an optically functional layer, the thickness of the pressure-sensitive adhesive layer containing a dye is preferably 25 μm or less.

The present invention also relates to an image display device having the polarizing film with an optical functional layer.

ADVANTAGEOUS EFFECTS OF INVENTION

The polarizing film with an optical functional layer of the present invention has an optical functional layer containing a coloring matter. The optical functional layer can adjust the color tone of the entire liquid crystal display device by absorbing a part of the wavelength of light with the pigment, and can improve the brightness by widening the color range. In particular, a dye having a maximum absorption wavelength in at least one of the wavelength ranges 470 to 510nm and 570 to 610nm can absorb unnecessary light emission in a wavelength range other than RGB (wavelength range 470 to 510nm and/or wavelength range 570 to 610 nm), suppress the unnecessary light emission, and is effective for widening the color gamut.

It is known that the discoloration of the dye in the optical functional layer containing the dye is caused by oxygen present in the atmosphere or in the resin penetrating into the optical functional layer and being activated by heat to attack the dye. It is considered that oxygen enters from the upper, lower, left and right surfaces of the pressure-sensitive adhesive layer.

In the polarizing film with an optical functional layer of the present invention, the optical functional layer containing a dye can be applied to a polarizing film using a polyvinyl alcohol polarizer. The polyvinyl alcohol based polarizer has a low oxygen permeability, and prevents oxygen from penetrating into the optical functional layer from the upper surface or the lower surface of the optical functional layer containing a dye. The polarizing film with an optical functional layer of the present invention can provide an optical functional layer that can prevent oxygen from entering the optical functional layer, can suppress discoloration (decomposition) of a coloring matter, and can stably maintain a wide color gamut over time by using a separator having a low oxygen transmission rate on the other surface of the optical functional layer until specific use, and by applying the polarizing film with an optical functional layer of the present invention to an adherend having a low oxygen transmission rate such as glass during specific use.

In the polarizing film with an optical functional layer of the present invention, the optical functional layer containing a coloring matter and the polyvinyl alcohol polarizer are laminated so that the distance therebetween is 45 μm or less. By setting the distance to 45 μm or less, oxygen entering from the end of the polarizing film with an optical function layer can be prevented, and discoloration (decomposition) of the coloring matter can be suppressed even at the end of the polarizing film with an optical function layer, and a wide color gamut can be stably maintained over time.

Drawings

Fig. 1 is a sectional view schematically showing the outline of the polarizing film with an optical functional layer of the present invention.

Fig. 2 is a sectional view schematically showing one embodiment of the polarizing film with an optically functional layer of the present invention.

Fig. 3 is a cross-sectional view schematically showing one embodiment of the polarizing film with an optically functional layer of the present invention.

Fig. 4 is a sectional view schematically showing one embodiment of the polarizing film with an optical functional layer of the present invention.

Description of the symbols

P polyvinyl alcohol polarizer

A optical functional layer

F transparent protective film

S-shaped diaphragm

B. C other layer

Distance between x polyvinyl alcohol polarizer and adhesive layer

Detailed Description

Hereinafter, embodiments of the polarizing film with an optical functional layer according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments shown in the drawings.

As shown in fig. 1, the polarizing film with an optical functional layer of the present invention includes a polyvinyl alcohol polarizer P and an optical functional layer a containing a dye. The polyvinyl alcohol-based polarizer P and the optical functional layer A are laminated so that the distance x therebetween is 45 μm or less. The shorter the distance x, the more oxygen can be prevented from entering from the end. The distance x is preferably 25 μm or less, more preferably 10 μm or less, still more preferably 5 μm or less, and yet more preferably 1 μm or less.

Fig. 2 shows a case where the polyvinyl alcohol polarizer P and the optically functional layer a are directly laminated (x =0 μm). Fig. 2 illustrates a polarizing film (one-sided protective polarizing film) having a transparent protective film F on the side of the polyvinyl alcohol-based polarizer P (the side on which the optical functional layer a is not provided). Fig. 2 illustrates a case where the base material S is provided on the optically functional layer a. The substrate S used until the polarizing film with an optical functional layer is used specifically includes a separator, a vapor deposited film, and the like. Specific examples of the material to be used include glass and a transparent substrate having a vapor-deposited layer.

Fig. 3 illustrates a case where the polyvinyl alcohol based polarizer P and the optical function layer a have a layer B having a thickness of 45 μm or less in the embodiment of fig. 2. In fig. 3, the case where the layer B is 1 layer is exemplified, but a plurality of layers may be combined. Examples of the layer B include: adhesive layers, film layers, and the like. The thickness of the layer B may be designed to be 45 μm or less in accordance with the characteristics of each layer.

Fig. 4 illustrates a case where the polyvinyl alcohol based polarizer P and the optical functional layer a are directly laminated (x =0 μm) and the optical functional layer a further includes a layer C in the embodiment of fig. 2. The case where the layer C is 1 layer is exemplified, but a plurality of layers may be combined. Examples of the layer C include: a pressure-sensitive adhesive layer, a surface-treated layer (a hard coat layer, an antiglare layer, an antireflection layer, etc.), and the like. The thickness of the layer C may be designed to be 45 μm or less in accordance with the characteristics of each layer. Layer C may also be used in combination with layer B.

The polarizing film with an optical functional layer of the present invention has a polarizing film having a polyvinyl alcohol polarizer and an optical functional layer containing a pigment. Hereinafter, each member will be described.

< optical functional layer >

The optically functional layer of the present invention is not particularly limited as long as it is a resin layer containing a pigment. Examples of the resin layer include a film layer and an adhesive layer. The optically functional layer may be formed from a composition containing a base polymer and a coloring matter.

< coloring matter >

Various pigments can be used as the pigment contained in the optical functional layer of the present invention. Examples of the coloring agent include: porphyrins, cyanines, azines, methylenepyrroles, and squaraines

Various compounds such as (squarylium), xanthene, oxonol, squaraine and the like. The pigment is preferably a tetraazaporphyrin pigment, from the viewpoint of widening the color gamut,Porphyrin-based pigments, cyanine-based pigments, squarylium compounds

The dye-like substance and the squarylium dye-like substance are preferably porphyrazine dye-like substances. The dye is specifically disclosed in Japanese patent laid-open publication No. 2011-116818 and the like. The above-mentioned coloring matters may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The dye preferably has a maximum absorption wavelength in at least one wavelength range of a wavelength range of 470 to 510nm and a wavelength range of 570 to 610 nm. The dye having the maximum absorption wavelength in the above wavelength range absorbs light unnecessary for color expression to suppress the light emission, and is effective for widening the color gamut. As the dye having the maximum absorption wavelength in the above wavelength range, a porphyrazine dye can be preferably used. For example, as the dye exhibiting the maximum absorption wavelength in the wavelength range of 570 to 610nm, there can be mentioned, for example: tetraazaporphyrin compounds (trade name: PD-320, PD311) manufactured by Shanghai chemical Co., ltd., tetraazaporphyrin compounds (trade name: FDG-007) manufactured by Shantian chemical industry Co., ltd., and the like. The maximum absorption wavelength of the dye was measured by a spectrophotometer (V-570 manufactured by Nippon Kagaku Co., ltd.).

The content of the coloring matter in the optically functional layer of the present invention can be adjusted depending on the absorption wavelength range of the coloring matter, the light absorption coefficient, and the kind of the base polymer, and is usually preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, and further preferably 0.1 to 1 part by weight, based on 100 parts by weight of the base polymer. Particularly, when a porphyrazine dye is used, the above range is preferable.

< adhesive layer >

The optical functional layer of the present invention may be a binder layer containing a pigment, and the binder layer may be formed from a binder composition containing a binder base polymer and a pigment. The kind of the adhesive base polymer is not particularly limited, and examples thereof include: various polymers such as rubber polymers, (meth) acrylic polymers, silicone polymers, urethane polymers, vinyl alkyl ether polymers, polyvinyl alcohol polymers, polyvinyl pyrrolidone polymers, polyacrylamide polymers, and cellulose polymers.

The adhesive composition of the present invention contains an adhesive base polymer as a main component. The main component is a component contained in the largest proportion of the total solid components contained in the binder composition, and for example, it means a component accounting for more than 50 wt%, and more specifically, accounting for more than 70 wt%, of the total solid components contained in the binder composition.

Among these adhesive base polymers, preferred are those excellent in optical transparency, exhibiting adhesive properties such as appropriate wettability, cohesiveness and adhesiveness, and also excellent in weather resistance, heat resistance and the like. As the polymer exhibiting such characteristics, a (meth) acrylic polymer can be preferably used. An acrylic adhesive that is a material for forming an adhesive layer and contains, as a base polymer, a (meth) acrylic polymer containing, as a monomer unit, an alkyl (meth) acrylate is described below.

[ meth (acrylic) Polymer ]

The (meth) acrylic polymer usually contains, as a main component, an alkyl (meth) acrylate as a monomer unit. The term (meth) acrylate refers to acrylate and/or methacrylate, and the meaning of (meth) acrylate in the present invention is the same.

Examples of the alkyl (meth) acrylate constituting the main skeleton of the (meth) acrylic polymer include linear or branched alkyl (meth) acrylates having 1 to 18 carbon atoms in the alkyl group. They may be used alone or in combination. The average carbon number of these alkyl groups is preferably 3 to 9.

In addition, from the viewpoint of adhesion characteristics, durability, adjustment of retardation, adjustment of refractive index, and the like, alkyl (meth) acrylates containing an aromatic ring such as phenoxyethyl (meth) acrylate and benzyl (meth) acrylate can be used.

In order to improve the adhesiveness and the heat resistance, 1 or more kinds of comonomers having a polymerizable functional group in which an unsaturated double bond is present, such as a (meth) acryloyl group or a vinyl group, may be introduced into the (meth) acrylic polymer by copolymerization. Specific examples of such comonomers include: hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, and (4-hydroxymethylcyclohexyl) methyl acrylate; carboxyl group-containing monomers such as (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; sulfonic acid group-containing monomers such as styrenesulfonic acid, allylsulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, propyl (meth) acrylate sulfonate, and (meth) acryloyloxynaphthalenesulfonic acid; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate, and the like.

Examples of the monomer for modification include: (N-substituted) amide monomers such as (meth) acrylamide, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide and N-methylol propane (meth) acrylamide; alkylaminoalkyl (meth) acrylate monomers such as aminoethyl (meth) acrylate, N-dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate; alkoxyalkyl (meth) acrylate monomers such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate; succinimide monomers such as N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyoctamethylene succinimide, and N-acryloylmorpholine; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide; and itaconimide monomers such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexyl itaconimide, N-cyclohexylitaconimide, and N-laurylitaconimide.

Further, as the modifying monomer, vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyl group

Vinyl monomers such as oxazole, vinyl morpholine, N-vinylcarboxylic acid amides, styrene, alpha-methylstyrene, and N-vinylcaprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; glycol acrylate monomers such as polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxyethylene glycol (meth) acrylate, and methoxypolypropylene glycol (meth) acrylate; acrylic ester monomers such as tetrahydrofurfuryl (meth) acrylate, fluorine-containing (meth) acrylate, silicone (meth) acrylate, and 2-methoxyethyl acrylate. Mention may also be made of: isoprene, butadiene, isobutylene, vinyl ether, and the like.

Examples of the copolymerizable monomer other than those described above include silane-based monomers containing a silicon atom. Examples of the silane monomer include: 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloxydecyltrimethoxysilane, 10-acryloxydecyltrimethoxysilane, 10-methacryloxydecyltriethoxysilane, 10-acryloxydecyltriethoxysilane, and the like.

Examples of the comonomer include polyfunctional monomers having 2 or more unsaturated double bonds such as (meth) acryloyl groups and vinyl groups, such as (meth) acrylic acid esters of polyhydric alcohols and (meth) acrylic acids, e.g., tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, bisphenol a diglycidyl ether di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and caprolactone-modified dipentaerythritol hexa (meth) acrylate, and polyester (meth) acrylates, epoxy (meth) acrylates, and urethane (meth) acrylates obtained by adding 2 or more unsaturated double bonds such as (meth) acryloyl groups and vinyl groups, which are the same functional groups as the monomer components, to the backbone of the polyester, epoxy, urethane, and the like.

The (meth) acrylic polymer contains, as a main component, an alkyl (meth) acrylate in a weight ratio of all constituent monomers, and the proportion of the comonomer in the (meth) acrylic polymer is not particularly limited, and the proportion of the comonomer is preferably about 0 to 20%, preferably about 0.1 to 15%, and more preferably about 0.1 to 10% in a weight ratio of all constituent monomers.

Among these comonomers, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferably used from the viewpoint of adhesiveness and durability. The hydroxyl group-containing monomer and the carboxyl group-containing monomer may be used in combination. These comonomers become reaction sites with the crosslinking agent when the adhesive composition contains the crosslinking agent. The hydroxyl group-containing monomer, carboxyl group-containing monomer, or the like is preferably used because it has a strong reactivity with the intermolecular crosslinking agent and can improve the cohesive property and heat resistance of the resulting pressure-sensitive adhesive layer. The hydroxyl group-containing monomer is preferred from the viewpoint of reworkability, and the carboxyl group-containing monomer is preferred from the viewpoint of compatibility between durability and reworkability.

When a hydroxyl group-containing monomer is contained as the comonomer, the proportion thereof is preferably 0.01 to 15% by weight, more preferably 0.03 to 10% by weight, and still more preferably 0.05 to 7% by weight. When a carboxyl group-containing monomer is contained as the comonomer, the proportion thereof is preferably 0.05 to 10% by weight, more preferably 0.1 to 8% by weight, and still more preferably 0.2 to 6% by weight.

The (meth) acrylic polymer of the present invention is generally a polymer having a weight average molecular weight in the range of 50 to 300 ten thousand. In view of durability, particularly heat resistance, a polymer having a weight average molecular weight of 70 to 270 ten thousand is preferably used, and more preferably 80 to 250 ten thousand. When the weight average molecular weight is less than 50 ten thousand, it is not preferable from the viewpoint of heat resistance. When the weight average molecular weight is more than 300 ten thousand, a large amount of a diluting solvent is required to adjust the viscosity for coating, which is not preferable because the cost increases. The weight average molecular weight is a value calculated by GPC (gel permeation chromatography) measurement and polystyrene conversion.

The production of such a (meth) acrylic polymer can be carried out by appropriately selecting known production methods such as solution polymerization, radiation polymerization such as UV polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations. The obtained (meth) acrylic polymer may be any copolymer such as a random copolymer, a block copolymer, or a graft copolymer.

In the solution polymerization, for example, ethyl acetate, toluene, or the like can be used as a polymerization solvent. As a specific example of the solution polymerization, the reaction is carried out under reaction conditions of about 50 to 70 ℃ and about 5 to 30 hours by adding a polymerization initiator under a stream of an inert gas such as nitrogen.

The polymerization initiator, chain transfer agent, emulsifier, and the like used in the radical polymerization are not particularly limited and may be appropriately selected and used. The weight average molecular weight of the (meth) acrylic polymer can be controlled by the amount of the polymerization initiator, the amount of the chain transfer agent, the reaction conditions, and the like, and the amount of the polymerization initiator, the amount of the chain transfer agent, the reaction conditions, and the like can be appropriately adjusted according to the type of the (meth) acrylic polymer.

Examples of the radical polymerization initiator include: 2,2' -azobisisobutyronitrile, 2' -azobis (2-amidinopropane) dihydrochloride, 2' -azobis [2- (5-methyl-2-imidazolin-2-yl) propane ] dihydrochloride, 2' -azobis (2-methylpropionamidine) disulfate, 2' -azobis (N, N ' -dimethyleneisobutylamidine), azo initiators such as 2,2' -azobis [ N- (2-carboxyethyl) -2-methylpropionamidine ] hydrate (manufactured by Wako pure chemical industries, ltd., VA-057), persulfates such as potassium persulfate and ammonium persulfate, bis (2-ethylhexyl) peroxydicarbonate, bis (4-tert-butylcyclohexyl) peroxydicarbonate, di-sec-butyl peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, dilauroyl peroxide, di-N-octanoyl peroxide, 1, 3-tetramethylbutyl peroxy-2-ethylhexanoate, bis (4-methylbenzoyl) peroxide, dibenzoyl peroxide, tert-butyl peroxyisobutyrate, 1-bis (tert-hexylperoxy) cyclohexane, tert-butyl hydroperoxide, peroxides such as hydrogen peroxide, combinations of persulfate and sodium hydrogen peroxide, redox initiators comprising a combination of a peroxide such as a combination of a peroxide and sodium ascorbate, and a reducing agent, and the like, but is not limited thereto.

The radical polymerization initiator may be used alone or in combination of 2 or more, and the total content thereof is preferably about 0.005 to 1 part by weight, more preferably about 0.02 to 0.5 part by weight, based on 100 parts by weight of the monomer.

Examples of the chain transfer agent include: dodecyl mercaptan, glycidyl mercaptan, thioglycolic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2, 3-dimercapto-1-propanol, and the like. The chain transfer agent may be used alone or in combination of 2 or more, and the total content thereof is preferably about 0.1 part by weight or less based on 100 parts by weight of the total amount of the monomer components.

Examples of the emulsifier used in the emulsion polymerization include: anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate and sodium polyoxyethylene alkylphenyl ether sulfate, nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester and polyoxyethylene-polyoxypropylene block polymer, and the like. These emulsifiers may be used alone in 1 kind, or in combination of 2 or more kinds.

Further, as the reactive emulsifier, emulsifiers having a radical polymerizable functional group such as an acryl group or an allyl ether group introduced thereto include, for example: AQUALON HS-10, HS-20, KH-10, BC-05, BC-10, BC-20 (all manufactured by first Industrial pharmaceutical Co., ltd.), ADEKA REASOAP SE10N (manufactured by Asahi electro chemical Co., ltd.), and the like. The reactive emulsifier is preferably incorporated into the polymer chain after polymerization, thereby improving water resistance. The amount of the emulsifier to be used is preferably 0.3 to 5 parts by weight, and more preferably 0.5 to 1 part by weight, from the viewpoint of polymerization stability and mechanical stability, based on 100 parts by weight of the total amount of the monomer components.

< crosslinking agent >

In the present invention, the binder composition for forming the binder layer having a pigment may contain a crosslinking agent. As the crosslinking agent, an organic crosslinking agent or a polyfunctional metal chelate compound can be used. Examples of the organic crosslinking agent include: isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents, imine crosslinking agents, and the like. The multifunctional metal chelate is formed by covalent bonding or coordination bonding of polyvalent metal and organic compound. As the polyvalent metal atom, there may be mentioned: al, cr, zr, co, cu, fe, ni, V, zn, in, ca, mg, mn, Y, ce, sr, ba, mo, la, sn, ti, etc. Examples of the atom in the covalently or coordinately bonded organic compound include an oxygen atom, and examples of the organic compound include: alkyl ester, alcohol compound, carboxylic acid compound, ether compound, ketone compound, and the like.

Examples of the isocyanate-based crosslinking agent include: isocyanate monomers such as toluene diisocyanate, phenylene diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and hydrogenated diphenylmethane diisocyanate, and isocyanate compounds, isocyanurate compounds, biuret compounds, and urethane prepolymer type isocyanates obtained by addition reaction of these isocyanate monomers with trimethylolpropane or the like, polyether polyols, polyester polyols, acrylic polyol esters, polybutadiene polyols, polyisoprene polyols, and the like. Particularly preferred is a polyisocyanate compound such as one selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate and isophorone diisocyanate or a polyisocyanate compound derived therefrom. Here, the polyisocyanate compound selected from one or derived from hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate includes hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, polyol-modified hexamethylene diisocyanate, polyol-modified hydrogenated xylylene diisocyanate, trimer-type hydrogenated xylylene diisocyanate, and polyol-modified isophorone diisocyanate. The polyisocyanate compounds exemplified are particularly preferable because the reaction with hydroxyl groups proceeds rapidly by using an acid or a base contained in the polymer as a catalyst, and this contributes particularly to the acceleration of the crosslinking speed.

The peroxide is suitably used as long as it is a peroxide which generates radical active species by heating or irradiation with light and crosslinks the base polymer of the pressure-sensitive adhesive composition, but in view of handling and stability, it is preferable to use a peroxide having a 1-minute half-life temperature of 80 to 160 ℃, and it is more preferable to use a peroxide having a 1-minute half-life temperature of 90 to 140 ℃.

Examples of the peroxide include: di (4-t-butylcyclohexyl) peroxydicarbonate (1-minute half-life temperature: 92.1 ℃ C.), di-sec-butyl peroxydicarbonate (1-minute half-life temperature: 92.4 ℃ C.), t-butyl peroxyneodecanoate (1-minute half-life temperature: 103.5 ℃ C.), t-hexyl peroxypivalate (1-minute half-life temperature: 109.1 ℃ C.), t-butyl peroxypivalate (1-minute half-life temperature: 110.3 ℃ C.), dilauroyl peroxide (1-minute half-life temperature: 116.4 ℃ C.), di-n-octanoyl peroxide (1-minute half-life temperature: 117.4 ℃ C.), 1, 3-tetramethylbutyl peroxy-2-ethylhexanoate (1-minute half-life temperature: 124.3 ℃ C.), di (4-methylbenzoyl) peroxide (1-minute half-life temperature: 128.2 ℃ C.), dibenzoyl peroxide (1-minute half-life temperature: 130.0 ℃ C.), t-butyl peroxyisobutyrate (1-minute half-life temperature: 136.1 ℃ C.), 1-di (t-tert-hexyl) peroxycyclohexane (1 minute half-life temperature: 149.2 ℃ C.), etc. Among them, bis (4-t-butylcyclohexyl) peroxydicarbonate (1-minute half-life temperature: 92.1 ℃ C.), dilauroyl peroxide (1-minute half-life temperature: 116.4 ℃ C.), dibenzoyl peroxide (1-minute half-life temperature: 130.0 ℃ C.) and the like are preferably used, particularly, from the viewpoint of excellent crosslinking reaction efficiency.

The half-life of the peroxide is an index for indicating the decomposition rate of the peroxide, and means the time until the residual amount of the peroxide becomes half. Regarding a decomposition temperature at which a half-life is obtained at an arbitrary time or a half-life time at an arbitrary temperature, it is described in a product catalog of manufacturers and the like, for example, in "organic peroxide product catalog (uptake of water-forming acid compound 1245925124649) 9 th edition (month 5 2003) and the like.

The amount of the crosslinking agent used in the pressure-sensitive adhesive composition is preferably 20 parts by weight or less, more preferably 0.01 to 20 parts by weight, and still more preferably 0.03 to 10 parts by weight, based on 100 parts by weight of a base polymer such as a (meth) acrylic polymer. When the amount of the crosslinking agent is more than 20 parts by weight, the moisture resistance is insufficient, and peeling is likely to occur in a reliability test or the like.

The adhesive composition for forming the adhesive layer having a coloring matter of the present invention may contain a silane coupling agent. By using the silane coupling agent, durability can be improved. Specific examples of the silane coupling agent include: examples of the coupling agent include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1, 3-dimethylbutylidene) propylamine and N-phenyl-gamma-aminopropyltrimethoxysilane, (meth) acrylic acid-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane, and isocyanate-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane.

The silane coupling agent may be used alone or in combination of 2 or more, and the total content thereof is preferably 0.001 to 5 parts by weight, more preferably 0.01 to 1 part by weight, even more preferably 0.02 to 1 part by weight, and even more preferably 0.05 to 0.6 part by weight, based on 100 parts by weight of the base polymer such as the (meth) acrylic polymer. This is an amount to improve durability and appropriately maintain adhesion to an optical member such as a liquid crystal cell.

In the present invention, a polyether-modified silicone may be blended in the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer having a pigment. Examples of the polyether-modified silicone include compounds disclosed in jp 2010-275522 a.

In the present invention, the pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer having a coloring matter may contain other known additives, and for example, powders of a coloring agent, a pigment, and the like, a dye, a surfactant, a plasticizer, a thickener, a surface lubricant, a leveling agent, a softener, an antioxidant, a light stabilizer, an ultraviolet absorber, a polymerization inhibitor, an inorganic or organic filler, metal powder, granules, foils, and the like may be added as appropriate depending on the application. In addition, redox species to which a reducing agent is added may be used within a controllable range.

The binder layer having a coloring matter is formed from the binder composition, and when the binder layer is formed, it is preferable to adjust the amount of the crosslinking agent to be added and to take the influences of the crosslinking temperature and the crosslinking time into consideration.

The crosslinking temperature and the crosslinking time can be adjusted depending on the crosslinking agent used. The crosslinking treatment temperature is preferably 170 ℃ or lower.

The crosslinking treatment may be performed at a temperature at the time of the drying step of the pressure-sensitive adhesive layer, or may be performed after the drying step by separately designing the crosslinking treatment step.

The crosslinking treatment time may be set in consideration of productivity and handling properties, but is usually about 0.2 to 20 minutes, preferably about 0.5 to 10 minutes.

The method for forming the binder layer having a pigment can be produced by the following method: for example, a method in which the pressure-sensitive adhesive composition is applied to a separator or the like subjected to a peeling treatment, and then dried to remove a polymerization solvent or the like to form a pressure-sensitive adhesive layer, followed by transfer to a polarizing film having a polyvinyl alcohol polarizer; or a method of applying the above adhesive composition to a polarizing film having a polyvinyl alcohol polarizer, and drying to remove a polymerization solvent or the like to form an adhesive layer on the polarizing film having a polyvinyl alcohol polarizer. When the binder is applied, one or more solvents other than the polymerization solvent may be added newly as appropriate.

As the separator subjected to the peeling treatment, a silicone release liner can be preferably used. In the step of forming the pressure-sensitive adhesive layer by applying the adhesive composition of the present invention to such a liner and drying the applied adhesive composition, a suitable method can be appropriately employed as a method for drying the pressure-sensitive adhesive according to the purpose. The method of drying the coating film by heating is preferably used. The heating and drying temperature is preferably 40 to 200 ℃, more preferably 50 to 180 ℃, and particularly preferably 70 to 170 ℃. By setting the heating temperature in the above range, an adhesive having excellent adhesive characteristics can be obtained.

The drying time may be suitably employed as appropriate. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

In addition, an adhesion promoting layer (for example, about 0.5 to 2 μm in thickness) may be formed on the surface of the polarizing film having the polyvinyl alcohol polarizer, or an adhesive layer may be formed after various easy adhesion treatments such as corona treatment and plasma treatment. In addition, the surface of the pressure-sensitive adhesive layer may be subjected to an easy-adhesion treatment.

As a method for forming the pressure-sensitive adhesive layer, various methods can be employed. Specific examples thereof include: roll coating, roll and lick coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, blade coating, air knife coating, curtain coating, lip coating, extrusion coating using a die coater, and the like.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, and is, for example, about 1 to 100. Mu.m, preferably about 2 to 50 μm, more preferably about 2 to 40 μm, and still more preferably about 5 to 35 μm. The thickness of the dye-containing pressure-sensitive adhesive layer is preferably 25 μm or less in terms of preventing oxygen from entering from the end of the pressure-sensitive adhesive layer.

In the case where the adhesive layer is exposed, the adhesive layer may be protected by a sheet (separator) subjected to a peeling treatment until it is put to practical use.

< film layer >

The optical functional layer of the present invention may be a layer containing a coloring matter, and the layer may be formed from a composition containing a base polymer for film formation and a coloring matter. As a material of the base polymer forming the film layer, the same material as a material constituting a transparent protective film described later can be exemplified. As the above-mentioned material, a cellulose resin such as cellulose triacetate, a polyester resin, (meth) acrylic resin, a cyclic polyolefin resin (norbornene-based resin), and the like are particularly preferably used. The film layer can be suitably used for a polyvinyl alcohol polarizer by using an adhesive, a pressure-sensitive adhesive, or the like.

Various methods can be used for forming the film layer containing a pigment. For example, the film layer can be produced by preparing a composition by mixing a colorant when particles of the resin material are dissolved in a solvent, and casting or extruding the composition. In this case, the film layer can be formed with an appropriate thickness. Additives may be appropriately added in the preparation of the above composition.

The thickness of the film layer is not particularly limited, and is, for example, about 1 to 100 μm, as in the case of the pressure-sensitive adhesive layer. Preferably 2 to 50 μm, more preferably 2 to 40 μm, and still more preferably 5 to 35 μm. The separator may be applied to a film layer containing a pigment.

Examples of the constituent material of the separator include: plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabrics, and suitable sheets such as nets, foamed sheets, metal foils, and laminates thereof, are preferably used from the viewpoint of excellent surface smoothness.

The plastic film is not particularly limited as long as it can protect the optically functional layer (particularly, pressure-sensitive adhesive layer), and examples thereof include: a polyvinyl alcohol film, a polyethylene film, a polypropylene film, a polybutylene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, an ethylene-vinyl acetate copolymer film, and the like.

The thickness of the separator is usually 5 to 200. Mu.m, preferably about 5 to 100. Mu.m. The separator may be subjected to release and antifouling treatment using a release agent of silicone type, fluorine type, long chain alkyl type or fatty acid amide type, silica powder or the like, or antistatic treatment of coating type, mixing type, vapor deposition type or the like, as required. In particular, the surface of the separator may be appropriately subjected to a release treatment such as a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment, thereby further improving the releasability from the optical functional layer (particularly, the pressure-sensitive adhesive layer).

The sheet subjected to the peeling treatment used in the production of the above-mentioned polarizing film with an adhesive layer can be used as it is as a separator for a polarizing film with an optical functional layer, and the process can be simplified.

As the above-mentioned separator, it is preferable to use one having an oxygen gas transmission rate of 1[ 2 ], [ cm ] ³ /(m ² ·24h·atm)]The following separators. The oxygen permeability is preferably 0.8[ cm ] ³ /(m ² ·24h·atm)]Hereinafter, it is further preferably 0.6[ 2 ], [ cm ] ³ /(m ² ·24h·atm)]Hereinafter, it is further preferably 0.5[ 2 ], [ cm ] ³ /(m ² ·24h·atm)]The following. The above oxygen transmission rate is determined by material, thickness, and the like. Oxygen transmission rate of optical member was measured specifically by the description of examplesAnd (4) determining.

As the separator satisfying the low oxygen gas permeability, for example, a polyvinyl alcohol film, a polyethylene terephthalate film, a film subjected to aluminum deposition, polyacrylonitrile, ethylene vinyl alcohol, or the like is preferable. The thickness of the film is preferably 10 to 100. Mu.m, and more preferably 25 to 75 μm.

< polarizing film >

The polarizing film of the present invention has the polyvinyl alcohol polarizer. The above polyvinyl alcohol polarizer has a low oxygen permeability and can satisfy the requirement of an oxygen permeability of 1[ 2 ], [ cm ] ³ /(m ² ·24h·atm)]The following.

As the polarizing film, a polarizing film having a transparent protective film on one surface or both surfaces of a polyvinyl alcohol polarizer is generally used.

The polyvinyl alcohol based polarizer is not particularly limited, and various polarizers can be used. Examples of the polarizer include films obtained by uniaxially stretching a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or an ethylene-vinyl acetate copolymer partially saponified film, a polyvinyl alcohol dehydrated product, and a polyvinyl chloride desalted product, and the like, in which a dichroic material such as iodine or a dichroic dye is adsorbed. Among them, a polarizer made of a dichroic material such as a polyvinyl alcohol film and iodine is preferable. The thickness of these polarizers is not particularly limited, but is usually about 80 μm or less.

The polarizer obtained by uniaxially stretching the polyvinyl alcohol film dyed with iodine can be produced, for example, by dyeing the polyvinyl alcohol film by immersing it in an aqueous iodine solution and stretching it to 3 to 7 times the original length. The sheet may be immersed in an aqueous solution of potassium iodide or the like optionally containing boric acid, zinc sulfate, zinc chloride or the like as necessary. Further, the polyvinyl alcohol film may be immersed in water and washed with water before dyeing, if necessary. By washing the polyvinyl alcohol film with water, it is possible to wash off dirt and an anti-blocking agent on the surface of the polyvinyl alcohol film, and also to swell the polyvinyl alcohol film and prevent unevenness such as uneven dyeing. The stretching may be performed after the dyeing with iodine, or may be performed while dyeing, or may be performed after the stretching with iodine. Stretching may be carried out in an aqueous solution or water bath of boric acid, potassium iodide, or the like.

Further, as the polarizer, a thin polarizer having a thickness of 10 μm or less can be used. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. Such a thin polarizer is preferable in that it has excellent durability because of its small thickness unevenness, excellent visibility, and small dimensional change, and can be made thin as the thickness of the polarizing film.

Typical examples of thin polarizers include thin polarizing films described in japanese patent laid-open nos. 51-069644, 2000-338329, WO2010/100917, and PCT/JP2010/001460, and japanese patent application nos. 2010-269002 and 2010-263692. These thin polarizing films can be obtained by a production method including a step of stretching a polyvinyl alcohol resin (hereinafter, also referred to as PVA-based resin) layer and a stretching resin base material in a state of a laminate, and a step of dyeing. With this production method, even if the PVA-based resin layer is thin, it can be stretched without causing troubles such as breakage due to stretching, because it is supported by the resin base material for stretching.

As the thin polarizing film, in a manufacturing method including a step of stretching in a state of a laminate and a step of dyeing, in view of being capable of improving polarizing performance by stretching at a high magnification, preferred are thin polarizers obtained by a manufacturing method including a step of stretching in an aqueous boric acid solution as described in WO2010/100917 pamphlet, PCT/JP2010/001460, japanese patent application 2010-269002, and japanese patent application 2010-263692, and particularly thin polarizers obtained by a manufacturing method including a step of stretching in an auxiliary gas atmosphere before stretching in an aqueous boric acid solution as described in japanese patent application 2010-269002 and japanese patent application 2010-263692.

As a material constituting the transparent protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, and the like can be used. Specific examples of such thermoplastic resins include cellulose resins such as cellulose triacetate, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, cyclic polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. A transparent protective film may be bonded to one surface of the polarizer via an adhesive layer, and a thermosetting resin or an ultraviolet curable resin such as (meth) acrylic, urethane, acrylic urethane, epoxy, or silicone may be used as the transparent protective film on the other surface. The transparent protective film may contain 1 or more kinds of any suitable additives. Examples of the additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, coloring inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and coloring agents. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, even more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. When the content of the thermoplastic resin in the transparent protective film is 50 wt% or less, high transparency and the like originally possessed by the thermoplastic resin may not be sufficiently exhibited.

The thickness of the transparent protective film is not particularly limited, but is, for example, about 10 to 90 μm, preferably 15 to 60 μm, and more preferably 20 to 50 μm. When a transparent protective film is disposed between the polyvinyl alcohol polarizer and the dye-containing pressure-sensitive adhesive layer, a transparent protective film whose total thickness with the pressure-sensitive adhesive layer or the like is adjusted to 45 μm or less may be used.

The surface of the transparent protective film to which the polarizer is not bonded may be provided with a functional layer (surface layer) such as a hard coat layer, an antireflection layer, an antisticking layer, a diffusion layer, or an antiglare layer.

The adhesive used for bonding the polarizer and the transparent protective film is not particularly limited as long as it is optically transparent, and various types of adhesives such as aqueous, solvent, hot melt, radical curing, and cation curing adhesives can be used, and an aqueous adhesive or a radical curing adhesive is preferred. The thickness of the adhesive layer is usually about 0.01 to 3 μm, preferably 0.3 to 2 μm, and more preferably 0.5 to 1.5 μm.

Examples of the layer having no pigment (for example, layer B in the embodiment of fig. 3) that can be provided between the polyvinyl alcohol polarizer and the binder layer having pigment include: the above adhesion promoting layer, the transparent protective film suitable for a polarizer, the adhesive layer (for adhering the transparent protective film to a polarizer), the adhesive layer (having no coloring matter), the retardation layer (or retardation film), the light scattering layer, the light emitting layer, the undercoat layer, the liquid crystal layer, the polarizing layer, and the like. The layer B may be used as a single layer, or may be a combination of a plurality of layers. When a plurality of layers B (e.g., layer B1 and layer B2) are used, a laminate can be used in which the plurality of layers B are laminated with a binder layer having no pigment, for example, polarizer P/layer B1/binder layer (having no pigment)/layer B2/binder layer a (having a pigment). The thickness of the layer B may be designed to be 45 μm or less depending on the characteristics of each layer. The layer B is preferably a layer having a low oxygen permeability.

< liquid Crystal Panel >

The polarizing film with an optically functional layer of the present invention described above can be preferably used when forming a liquid crystal panel. For example, in the case of the polarizing film with an adhesive layer in which the optical functional layer of the polarizing film with an optical functional layer of the present invention is an adhesive layer, the polarizing film with an adhesive layer is bonded to at least one surface of the liquid crystal cell via the adhesive layer of the polarizing film with an adhesive layer, thereby forming a liquid crystal panel. The polarizing film with an adhesive layer of the present invention can be preferably used for the viewing side of a liquid crystal cell.

The liquid crystal cell may be any type of liquid crystal cell such as TN type, STN type, pi type, VA type, IPS type, and the like, and the liquid crystal panel of the present invention preferably uses an IPS mode liquid crystal cell.

In addition to the polarizing film, other optical layers may be used in the formation of the liquid crystal panel. The optical layer is not particularly limited, and for example, optical layers used for forming a liquid crystal panel such as a 1-layer or 2-layer or more reflective sheet, semi-transmissive sheet, retardation sheet (including 1/2, 1/4, or the like wave plate), vision compensation film, and luminance improvement film can be used on the visible side and/or the back side of the liquid crystal cell.

< liquid Crystal display device >

The liquid crystal display device can be formed by appropriately assembling the components such as the above-described liquid crystal panel and the lighting system used as necessary and introducing them into a driver circuit. In forming a liquid crystal display device, for example, a 1-layer or 2-layer or more diffusion sheet, an antiglare layer, an antireflection film, a protective sheet, a prism array, a lens array sheet, a light diffusion sheet, a backlight, and other suitable members may be disposed at appropriate positions. Further, a liquid crystal display device such as a liquid crystal display device using a backlight or a reflector in a lighting system can be suitably formed.

Examples

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In each example, parts and% are on a weight basis. Hereinafter, the room temperature conditions are 23 ℃ and 65% RH, respectively, unless otherwise specified.

[ measurement of weight average molecular weight of (meth) acrylic Polymer >

The weight average molecular weight (Mw) of the (meth) acrylic polymer was measured by GPC (gel permeation chromatography). Mw/Mn was also measured in the same manner.

An analysis device: HLC-8120GPC, manufactured by Tosoh corporation

Column: G7000H, manufactured by Tosoh corporation _XL +GMH _XL +GMH _XL

Column size: each 7.8mm phi x 30cm for a total of 90cm

Column temperature: 40 deg.C

Flow rate: 0.8mL/min

Injection amount: 100 μ L

Eluent: tetrahydrofuran (THF)

The detector: differential Refractometer (RI)

Standard sample: polystyrene

< measurement of oxygen Transmission Rate >

The oxygen transmission rate was determined according to JIS K7126-2 at 23 ℃ and 0% RH using an oxygen transmission rate measuring apparatus OX-TRAN manufactured by MOCON.

Example 1

< preparation of polarizing film >

In order to produce a thin polarizing layer, a laminate in which a PVA layer having a thickness of 9 μm was formed on an amorphous PET substrate was first subjected to auxiliary stretching at a stretching temperature of 130 ℃ in a gas atmosphere to obtain a stretched laminate, the stretched laminate was then dyed to obtain a colored laminate, and the colored laminate was further stretched in boric acid water at a stretching temperature of 65 ℃ to integrally stretch the colored laminate with the amorphous PET substrate to obtain an optical film laminate including a PVA layer having a thickness of 4 μm such that the total stretching ratio was 5.94 times. By such 2-step stretching, an optical film laminate including a PVA layer having a thickness of 4 μm and constituting a high-performance polarizing layer in which PVA molecules of the PVA layer formed on the amorphous PET substrate are highly oriented and iodine adsorbed by dyeing is highly oriented in one direction in the form of a polyiodide complex can be produced. Further, a polyvinyl alcohol adhesive (the thickness of the adhesive layer formed was 1 μm) was applied to the surface of the polarizing layer of the optical film laminate, and a saponified 40 μm-thick 1 st acrylic resin film (oxygen transmission rate 5[ cm ] cm) ³ /(m ² ·24h·atm)]) Then, the amorphous PET substrate was peeled off to prepare a polarizer using a thin type polarizer (oxygen permeability: less than 0.02[ 2 ], [ cm ] ³ /(m ² ·24h·atm)]) The single-sided protective polarizing film of (1). This is referred to as a thin single-sided protective polarizing film.

< preparation of (meth) acrylic Polymer >

A monomer mixture containing 100 parts of butyl acrylate, 0.01 part of 2-hydroxyethyl acrylate and 5 parts of acrylic acid was charged into a reaction vessel equipped with a condenser, a nitrogen inlet tube, a thermometer and a stirrer. Further, 0.1 part of 2,2' -azobisisobutyronitrile as a polymerization initiator was added to 100 parts of the monomer mixture together with 100 parts of ethyl acetate, nitrogen gas was introduced while slowly stirring the mixture for nitrogen gas substitution, and then the liquid temperature in the flask was kept near 55 ℃ to perform a polymerization reaction for 8 hours, thereby preparing a solution of an acrylic polymer having a weight average molecular weight (Mw) of 180 ten thousand and an Mw/Mn =4.1 (solid content concentration 30 wt%).

(preparation of adhesive composition)

A pressure-sensitive adhesive composition was obtained by mixing 0.3 parts of benzoyl peroxide (trade name NYPER BMT manufactured by Nippon fat and oil Co., ltd.), 1 part of an isocyanate-based crosslinking agent (trade name Coronate L manufactured by Tosoh chemical Co., ltd.), and 0.25 part of a porphyrazine dye (trade name PD-320 manufactured by Shanghai chemical Co., ltd.: having a maximum absorption wavelength at 595 nm) with respect to 100 parts of the solid content of the acrylic polymer solution manufactured as described above.

(preparation of polarizing film with adhesive layer)

The adhesive composition was directly and uniformly applied to the polarizer (PVA layer) surface of the thin one-side protective polarizing film using an applicator, and the film was dried in an air circulating oven at 155 ℃ for 2 minutes to form an adhesive layer having a dye with a thickness of 20 μm on the polarizer surface, thereby producing a one-side protective polarizing film with an adhesive layer.

Example 2

A one-side protective polarizing film with an adhesive layer was produced in the same manner as in example 1, except that in example 1, an adhesive layer having no pigment and having a thickness of 20 μm was laminated on the surface of the polarizer, and then an adhesive layer having a pigment and having a thickness of 20 μm was formed.

In the case of forming a binder layer having no pigment and having a thickness of 20 μm, the same binder composition was used except that no pigment was blended in the binder composition for forming the binder layer having the pigment. The pressure-sensitive adhesive layer was formed by uniformly applying the pressure-sensitive adhesive composition to the surface of a release substrate (MRF 38CK manufactured by mitsubishi resin corporation) of a polyethylene terephthalate film treated with a silicone-based release agent by an applicator, drying the applied pressure-sensitive adhesive composition in an air-circulating oven at 155 ℃ for 2 minutes, and transferring the pressure-sensitive adhesive layer to the polarizer and laminating the pressure-sensitive adhesive layer.

Example 3

A one-side protective polarizing film with an adhesive layer was produced in the same manner as in example 1, except that in example 1, 2 adhesive layers having no pigment and having a thickness of 20 μm (total thickness: 40 μm) used in example 2 were laminated on the surface of the polarizer, and then the adhesive layer having a pigment and having a thickness of 20 μm was formed. The formation of the binder layer having no pigment was the same as that described in example 2.

Example 4

< preparation of polarizing film >

A saponified 2 nd acrylic resin film (having a thickness of 40 μm, 5[ oxygen gas transmission rate ], [2 ] cm) was bonded with an adhesive (thickness of adhesive layer, 1 μm) ³ /(m ² ·24h·atm)]) The polarizing film was laminated on the polarizer (PVA layer) surface of the thin single-sided protective polarizing film obtained in example 1 to prepare a double-sided protective polarizing film. This is referred to as a thin two-sided protective polarizing film.

(production of polarizing film with adhesive layer)

The pressure-sensitive adhesive composition used in example 1 was directly and uniformly applied to the back surface (opposite to the pressure-sensitive adhesive layer) of the 2 nd acrylic resin film of the above-mentioned both-side protective polarizing film by an applicator, and dried in an air circulation type oven at 155 ℃ for 2 minutes to form a pressure-sensitive adhesive layer having a dye with a thickness of 20 μm on the back surface of the 2 nd acrylic resin film, thereby producing a one-side protective polarizing film having a pressure-sensitive adhesive layer.

Comparative example 1

A one-side protective polarizing film with an adhesive layer was produced in the same manner as in example 1, except that in example 1,3 adhesive layers having no pigment and having a thickness of 20 μm used in example 2 were laminated on the surface of the polarizer (total thickness: 60 μm), and then an adhesive layer having a pigment and having a thickness of 20 μm was formed. The formation of the binder layer having no pigment was the same as that described in example 2.

Comparative example 2

In example 1, the above adhesive composition was formed on a saponified acrylic resin film (oxygen transmission rate 5[ 2 ], [ cm ] having a thickness of 40 μm ³ /(m ² ·24h·atm)]) An acrylic resin film with a pressure-sensitive adhesive layer was produced in the same manner as in example 1, except that the pressure-sensitive adhesive layer was formed on the polarizer (PVA layer) side of the thin one-side protective polarizing film.

The polarizing film with pressure-sensitive adhesive layer protected on one side or both sides or the acrylic resin film with pressure-sensitive adhesive layer obtained in the above examples and comparative examples were used as samples, and the following evaluations were carried out. The evaluation results are shown in table 1.

(evaluation of discoloration)

After the sample was cut into a test piece of 50mm in length by 25mm in width, the front and end portions were obtained as photographs (initial) using a scanner (specifically, a product name PIXUS MX923 manufactured by Canon corporation). Next, a durability test was performed in which the sample was left to stand at a constant temperature of 85 ℃ for 24 hours, and then, the sample was taken out and returned to room temperature (23 ℃), and then, the front and end portions of the sample were again obtained as photographs (after 24 hours) by the same scanner. The photographs before (initial) and after (24) hours after the above-mentioned test were binarized, and the presence or absence of discoloration in the front face and the amount of discoloration in the end portion were measured by the following methods.

< discoloration of front surface >

Whether or not the test piece was discolored was evaluated by visual observation based on the images of the binarized photograph before the test piece was put into the durability test and the binarized photograph after the test piece was put into the durability test. The transmittance before and after the test piece was subjected to the durability test is shown in table 1. The transmittance was measured at 23 ℃ using a spectral transmittance measuring instrument with an integrating sphere (Dot-3 c, institute of color technology in village).

The o color was not different from that before the input.

The color of x was significantly lighter than before the input.

< decolorization of end portion >

The longest portion of the portion where discoloration is evident at the peripheral end was measured with a straight edge from the peripheral end toward the center of the test piece and evaluated as discoloration (discoloration-progressing distance: mm).

In the examples, the front surface was not discolored, and the amount of discoloration at the end was small. The discoloration at the end (discoloration-progressing distance: mm) is preferably 3mm or less, more preferably 2mm or less, still more preferably 1mm or less, and preferably 0mm. On the other hand, in comparative example 1, since the polyvinyl alcohol polarizer was used, no discoloration of the front surface was observed, but the distance between the polyvinyl alcohol polarizer and the optical functional layer (pressure-sensitive adhesive layer) was more than 45 μm, and discoloration of the edge portion (discoloration-progressing distance: mm) was observed. In comparative example 2, since the polyvinyl alcohol polarizer was not used, both front discoloration and end discoloration were observed.

Claims (5)

1. A polarizing film with an optically functional layer, which has a pressure-sensitive adhesive layer containing a coloring matter and a base polymer on at least one side of a polarizing film having a polyvinyl alcohol polarizer, wherein the distance between the polyvinyl alcohol polarizer and the pressure-sensitive adhesive layer containing the coloring matter is 25 [ mu ] m or less,

the base polymer of the adhesive layer is a (meth) acrylic polymer,

an adhesive layer and a transparent protective film are provided between the polarizer and the adhesive layer,

the thickness of the transparent protective film is more than 10 μm,

the total thickness of the transparent protective film and the adhesive layer is 25 [ mu ] m or less,

the adhesive layer adheres the polarizer and the transparent protective film together, and the thickness of the adhesive layer is 0.01 to 3 μm.

2. The polarizing film with an optically functional layer according to claim 1,

the polyvinyl alcoholThe oxygen transmission rate of the polarizer-like mirror is 1[ 2 ], [ cm ] ³ /(m ² ·24h·atm)]The following.

3. The polarizing film with an optically functional layer according to claim 1,

the thickness of the dye-containing adhesive layer is 25 μm or less.

4. The polarizing film with an optically functional layer according to claim 1,

the weight average molecular weight of the (meth) acrylic polymer is 50 to 300 ten thousand.

5. An image display device having the polarizing film with an optically functional layer according to any one of claims 1 to 4.

Images