JP6154054B2 - Polarizing film with pressure-sensitive adhesive layer, method for producing the same, and image display device - Google Patents

Description

  The present invention relates to a polarizing film with a pressure-sensitive adhesive layer and a method for producing the same. The pressure-sensitive adhesive layer-attached polarizing film can form an image display device such as a liquid crystal display device (LCD) or an organic EL display device alone or as an optical film obtained by laminating the polarizing film.

  In a liquid crystal display device or the like, it is indispensable to dispose polarizing elements on both sides of a liquid crystal cell because of its image forming method, and generally a polarizing film is attached. When sticking the said polarizing film to a liquid crystal cell, an adhesive is normally used. Moreover, since adhesion | attachment of a polarizing film and a liquid crystal cell reduces the loss of light normally, each material is closely_contact | adhered using the adhesive. In such a case, since the adhesive has the merit that a drying step is not required to fix the polarizing film, the adhesive is a polarizing film with an adhesive layer provided in advance as an adhesive layer on one side of the polarizing film. A film is generally used. A release film is usually attached to the pressure-sensitive adhesive layer of the polarizing film with a pressure-sensitive adhesive layer.

  For the formation of the pressure-sensitive adhesive layer, a pressure-sensitive adhesive containing a base polymer and a crosslinking agent is usually used. As the base polymer, an acrylic polymer is awarded, and as the crosslinking agent, an isocyanate-based crosslinking agent is awarded.

  Moreover, the polarizing film with an adhesive layer using the piece protection polarizing film which provided the protection film only on the single side | surface of the polarizer from the viewpoint of thickness reduction is proposed. However, the polarizing film with the pressure-sensitive adhesive layer using the single-protective polarizing film has a shrinkage stress of the polarizer on the side provided with the protective film under a severe environment such as thermal shock (for example, a test at 95 ° C. for 250 hours). Due to the difference in shrinkage stress of the polarizer opposite to the protective film, excessive stress is generated inside the polarizer so that it penetrates the entire surface from a minute crack of several hundred μm in the direction of the absorption axis of the polarizer. There is a problem that various cracks are easily generated up to a through crack. That is, the piece protective polarizing film with an adhesive layer was not sufficiently durable in the harsh environment.

  Providing a protective layer made of a water-soluble film-forming composition (polyvinyl alcohol-based resin composition) on at least one surface of the polarizer from the viewpoint of reducing the thickness and weight while suppressing the occurrence of the through cracks. It has been proposed (Patent Document 1).

JP 2005-043858 A

  As described above, when a protective layer (anchor coat layer) formed from a polyvinyl alcohol-based resin composition is provided and a pressure-sensitive adhesive layer containing an isocyanate-based crosslinking agent is further provided in the protective layer, The protective layer and the pressure-sensitive adhesive layer have a good anchoring force due to the reaction between the hydroxyl group derived from the polyvinyl alcohol-based resin in the layer and the isocyanate group derived from the isocyanate-based crosslinking agent in the pressure-sensitive adhesive layer.

  However, the pressure-sensitive adhesive layer containing an isocyanate-based crosslinking agent has a hardness corresponding to dent resistance and processability, and after securing the anchoring force, after forming the pressure-sensitive adhesive layer, A predetermined aging time was required until shipment. Moreover, since the self-crosslinking reaction advances, the adhesive composition containing an isocyanate-based crosslinking agent has a pot life as an adhesive composition and is difficult to handle. On the other hand, in the pressure-sensitive adhesive composition containing no isocyanate-based crosslinking agent, the anchoring property with the anchor coat layer formed from the polyvinyl alcohol-based resin composition is not sufficiently satisfactory.

  The present invention is a polarizing film with a pressure-sensitive adhesive layer having a polarizer, an anchor coat layer containing a water-based resin, and a pressure-sensitive adhesive layer in this order, even if the pressure-sensitive adhesive layer does not contain an isocyanate-based crosslinking agent. An object of the present invention is to provide a polarizing film with an adhesive layer in which the anchoring force between the anchor coat layer and the adhesive layer is good.

  Moreover, an object of this invention is to provide the manufacturing method of the said polarizing film with an adhesive layer. Moreover, this invention relates to the image display apparatus which has the said polarizing film with an adhesive layer.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by the following polarizing film with a pressure-sensitive adhesive layer, etc., and have reached the present invention.

That is, the present invention is a polarizing film with a pressure-sensitive adhesive layer having a polarizer, an anchor coat layer and a pressure-sensitive adhesive layer in this order,
The anchor coat layer is formed from an aqueous resin composition containing an aqueous resin and a compound (a) having at least one primary alcohol capable of reacting with a hydroxyl group at a molecular end;
The pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition containing a hydroxyl group-containing base polymer and a mercapto group-containing silane coupling agent, and relates to a polarizing film with a pressure-sensitive adhesive layer.

  In the pressure-sensitive adhesive layer-attached polarizing film, the aqueous resin may be at least one selected from polyvinyl alcohol resins, polyurethane resins, and oxazoline group-containing polymers. As the water-based resin, a polyvinyl alcohol-based resin is preferable. The polyvinyl alcohol-based resin preferably has a saponification degree of 96 mol% or more and an average polymerization degree of 2000 or more.

  In the polarizing film with an adhesive layer, the aqueous resin composition preferably contains 0.2 to 20 parts by weight of the compound (a) with respect to 100 parts by weight of the aqueous resin.

  In the polarizing film with an adhesive layer, methylol melamine can be preferably used as the compound (a).

  In the polarizing film with an adhesive layer, the anchor coat layer preferably has a thickness of 0.05 μm to 6 μm.

  In the pressure-sensitive adhesive layer-attached polarizing film, a (meth) acrylic polymer having a hydroxyl group can be used as the base polymer having a hydroxyl group.

  In the polarizing film with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive composition preferably contains 0.01 to 5 parts by weight of the mercapto group-containing silane coupling agent with respect to 100 parts by weight of the base polymer having a hydroxyl group. .

  In the polarizing film with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive composition may contain a crosslinking agent. The crosslinking agent preferably contains a crosslinking agent (b) that does not react with hydroxyl groups. The crosslinking agent (b) that does not react with the hydroxyl group is preferably a peroxide.

  In the polarizing film with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive composition contains 0.01 to 2 parts by weight of a crosslinking agent (b) that does not react with the hydroxyl group with respect to 100 parts by weight of the base polymer having a hydroxyl group. It is preferable.

  In the polarizing film with an adhesive layer, the polarizer preferably has a thickness of 15 μm or less.

In the polarizing film with the pressure-sensitive adhesive layer, the polarizer has optical properties represented by the following formula:
P> − (10 ^0.929T-42.4 −1) × 100 (where T <42.3), and
It is preferably configured to satisfy the condition of P ≧ 99.9 (however, T ≧ 42.3).

  The polarizing film with an adhesive layer may have a protective film on at least one side of the polarizer.

  In the polarizing film with the pressure-sensitive adhesive layer, a separator can be laminated on the pressure-sensitive adhesive layer.

The present invention is also a method for producing the polarizing film with the pressure-sensitive adhesive layer,
On the polarizer, an aqueous resin composition containing a water-based resin and a compound (a) having at least one primary alcohol capable of reacting with a hydroxyl group at the molecular end is coated, then dried, and anchored. Forming a coat layer;
Forming a pressure-sensitive adhesive layer on the anchor coat layer from a pressure-sensitive adhesive composition containing a base polymer having a hydroxyl group and a mercapto group-containing silane coupling agent;
The manufacturing method of the polarizing film with an adhesive layer characterized by having.

  Moreover, this invention relates to the image display apparatus which has the said polarizing film with an adhesive layer.

The polarizing film with an adhesive layer of the present invention has a polarizer, an anchor coat layer containing an aqueous resin, and an adhesive layer in this order.
The anchor coat layer contains a compound (a) having at least one primary alcohol capable of reacting with a hydroxyl group at the molecular end, for example, methylol melamine, and the pressure-sensitive adhesive layer contains a mercapto group-containing silane coupling. Contains agents. The terminal primary alcohol such as methylol melamine in the anchor coat layer reacts with an aqueous resin (for example, polyvinyl alcohol resin) of the anchor coat layer, while the mercapto group-containing silane cup in the pressure-sensitive adhesive layer. It is thought to react with the silanol group of the ring agent. Furthermore, when the anchor coat layer is directly provided on the polarizer, the terminal primary alcohol such as methylol melamine in the anchor coat layer is derived from the polyvinyl alcohol resin in the polarizer. It is thought to react with hydroxyl groups. Moreover, it is thought that the silanol group of a mercapto group containing silane coupling agent reacts with the hydroxyl group derived from the base polymer in an adhesive layer. In addition, it is considered that the mercapto group-containing silane coupling agent can enhance the crosslinking of the pressure-sensitive adhesive layer by forming a sulfide bond by self-condensation by reaction between mercapto groups (—SH, thiol groups) in the pressure-sensitive adhesive layer. . As described above, the anchor coat layer and each material in the pressure-sensitive adhesive layer are combined by reacting, so that the anchor coat layer and the pressure-sensitive adhesive layer do not contain an isocyanate-based crosslinking agent. The pressure-sensitive adhesive layer is considered to have good anchoring properties.

It is an example of schematic sectional drawing of the polarizing film with an adhesive layer of this invention. It is an example of schematic sectional drawing of the polarizing film with an adhesive layer of this invention. It is an example of schematic sectional drawing of the polarizing film with an adhesive layer of this invention.

  Hereinafter, the polarizing films 10, 11, and 12 with an adhesive layer of the present invention will be described with reference to FIGS. 1 to 3. The polarizing films 10, 11, 12 with an adhesive layer have a polarizer 1, an anchor coat layer 2 containing an aqueous resin, and an adhesive layer 3 in this order. In the polarizing films 10 and 11 with pressure-sensitive adhesive layers of the present invention, as shown in FIGS. 1 and 2, the polarizer 1 is directly provided with the anchor coat layer 2 formed from an aqueous resin composition containing an aqueous resin. be able to. As shown in FIGS. 2 and 3, protective films 5 and 5 ′ can be provided on one side or both sides of the polarizer 1. In FIG. 2, in the polarizing film 10 with an adhesive layer, the case where it has the protective film 5 on the opposite side to the side which provides the anchor coat layer 2 of the polarizer 1 is illustrated. Moreover, in FIG. 3, when the polarizing film 10 with an adhesive layer has the protective films 5 and 5 'on both sides of the polarizer 1, and the anchor coat layer 2 is provided on the protective film 5' side. Is illustrated. Although not shown in FIGS. 2 and 3, the polarizer 1 and the protective film 5 are laminated via intervening layers such as an adhesive layer, a pressure-sensitive adhesive layer, and an undercoat layer (primer layer). Although not shown, the easy-adhesion layer and the adhesive layer can be laminated by providing an easy-adhesion layer or applying an activation treatment to the protective films 5 and 5 '.

  Moreover, as for the polarizing films 10 and 11 with an adhesive layer of this invention, the separator 4 can be provided in the adhesive layer 3, as shown in FIG. In addition, when the polarizing film 11 with an adhesive layer has the protective film 5 like FIG. 2, FIG. 3, a surface protective film can be provided in the protective film 5. FIG.

<Polarizer>
The polarizer is not particularly limited, and various types can be used. Examples of polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. Examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally 2 to 25 μm.

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

  As the polarizer, a thin polarizer having a thickness of 15 μm or less can be used. The thickness of the polarizer is preferably 12 μm from the viewpoint of thinning and crack resistance due to thermal shock, more preferably 10 μm or less, further 8 μm or less, further 7 μm or less, and further 6 μm or less. On the other hand, the thickness of the polarizer is preferably 2 μm or more, and more preferably 3 μm or more. Such a thin polarizer has less thickness unevenness, excellent visibility, and less dimensional change, and therefore excellent durability against thermal shock.

As a thin polarizer having a thickness of 15 μm or less, typically,
Patent No. 4751486,
Japanese Patent No. 4751481,
Patent No. 4815544,
Patent No. 5048120,
Japanese Patent No. 5587517,
International Publication No. 2014/077599 pamphlet,
International Publication No. 2014/077636 Pamphlet,
Or the like, or a thin polarizing film (polarizer) obtained from the production method described therein.

The polarizer has an optical characteristic represented by a single transmittance T and a degree of polarization P of the following formula P> − (10 ^0.929T-42.4 −1) × 100 (where T <42.3) and It is preferably configured to satisfy the condition of P ≧ 99.9 (however, T ≧ 42.3). A polarizing film configured so as to satisfy the above-described conditions uniquely has performance required as a display for a liquid crystal television using a large display element. Specifically, the contrast ratio is 1000: 1 or more and the maximum luminance is 500 cd / m ² or more. As other uses, for example, it is bonded to the viewing side of the organic EL display device.

  As the thin polarizing film, among the production methods including the step of stretching in the state of a laminate and the step of dyeing, Patent No. 4751486, Patent, in that the polarizing performance can be improved at a high magnification. What is obtained by the manufacturing method including the process of extending | stretching in a boric-acid aqueous solution as described in the 4751481 specification and the patent 4815544 specification is preferable, and it describes especially in the patent 4751481 specification and the patent 4815544 specification. What is obtained by the manufacturing method including the process of extending | stretching in the air auxiliary before extending | stretching in the boric-acid aqueous solution which has this is preferable. These thin polarizing films can be obtained by a production method including a step of stretching a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin base material in a laminated state and a step of dyeing. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching by being supported by the stretching resin substrate.

<Protective film>
As the material constituting the protective film, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier 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, styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin) And polymers based on polycarbonate and polycarbonate. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Polymer blends and the like can also be mentioned as examples of the polymer forming the protective film. These protective films are usually bonded to the polarizer by an adhesive layer. In addition, the protective film is applied to a polarizer using a (meth) acrylic, urethane-based, acrylurethane-based, epoxy-based, or silicone-based thermosetting resin or ultraviolet curable resin, and cured. Can be formed.

  A retardation film can be used as the protective film. Examples of the retardation film include those having a front retardation of 40 nm or more and / or a retardation having a thickness direction retardation of 80 nm or more. The front phase difference is usually controlled in the range of 40 to 200 nm, and the thickness direction phase difference is usually controlled in the range of 80 to 300 nm. In the case where a retardation film is used as the protective film, the retardation film functions also as a polarizer protective film, so that the thickness can be reduced.

  Examples of the retardation film include a birefringent film formed by uniaxially or biaxially stretching a thermoplastic resin film. The stretching temperature, stretching ratio, and the like are appropriately set depending on the retardation value, film material, and thickness.

  The thickness of the protective film can be determined as appropriate, but in general, it is preferably 3 to 200 μm, more preferably 3 to 100 μm from the viewpoints of workability such as strength and handleability, and thin layer properties. Is preferred. In particular, the thickness of the protective film (when a film is formed in advance) is preferably 10 to 60 μm, more preferably 10 to 45 μm from the viewpoint of transportability. On the other hand, the thickness of the protective film (when formed by coating and curing) is preferably 3 to 25 μm, more preferably 3 to 20 μm from the viewpoint of transportability. The protective film may be used in a plurality of layers or in a plurality of layers.

  A functional layer such as a hard coat layer, an antireflection layer, an antisticking layer, a diffusion layer or an antiglare layer can be provided on the surface of the protective film to which the polarizer is not adhered. In addition, the hard coat layer, the antireflection layer, the antisticking layer, the diffusion layer, the antiglare layer, and other functional layers can be provided on the protective film itself, or can be provided separately from the protective film. it can.

<Intervening layer>
The protective film and the polarizer are laminated via an intervening layer such as an adhesive layer, an adhesive layer, and an undercoat layer (primer layer). At this time, it is desirable that the both are laminated without an air gap by an intervening layer.

  The adhesive layer is formed of an adhesive. The type of the adhesive is not particularly limited, and various types can be used. The adhesive layer is not particularly limited as long as it is optically transparent. Examples of the adhesive include water-based, solvent-based, hot-melt-based, active energy ray-curable types, and the like. Or an active energy ray hardening-type adhesive agent is suitable.

  Examples of the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, and a water-based polyester. The water-based adhesive is usually used as an adhesive made of an aqueous solution, and usually contains 0.5 to 60% by weight of a solid content.

  The active energy ray curable adhesive is an adhesive that cures by an active energy ray such as an electron beam or ultraviolet rays (radical curable type, cationic curable type), for example, in an electron beam curable type or an ultraviolet curable type. Can be used. As the active energy ray curable adhesive, for example, a photo radical curable adhesive can be used. When the photo radical curable active energy ray curable adhesive is used as an ultraviolet curable adhesive, the adhesive contains a radical polymerizable compound and a photo polymerization initiator.

  Moreover, when using an aqueous adhesive etc., it is preferable to apply the adhesive so that the thickness of the finally formed adhesive layer is 30 to 300 nm. The thickness of the adhesive layer is more preferably 60 to 250 nm. On the other hand, when an active energy ray-curable adhesive is used, the thickness of the adhesive layer is preferably 0.1 to 200 μm. More preferably, it is 0.5-50 micrometers, More preferably, it is 0.5-10 micrometers.

  In addition, in laminating | stacking a polarizer and a protective film, an easily bonding layer can be provided between a protective film and an adhesive bond layer.

<Anchor coat layer>
The anchor coat layer contains a water-based resin. The anchor coat layer can be formed, for example, by applying an aqueous resin composition containing an aqueous resin to a polarizer. As the aqueous resin, for example, at least one selected from polyvinyl alcohol resins, polyurethane resins, and oxazoline group-containing polymers can be used. Among these, when the anchor coat layer is directly formed on the polarizer as shown in FIGS. 1 and 2, a polyvinyl alcohol resin is preferable as the aqueous resin from the viewpoint of suppressing the occurrence of through cracks. On the other hand, as shown in FIG. 3, when an anchor coat layer is formed on a protective film, the water-based resin is preferably a polyurethane resin or an oxazoline group-containing polymer from the viewpoint of coating film formation and wettability with respect to the protective film. .

  As said polyvinyl alcohol-type resin, polyvinyl alcohol is mentioned, for example. Polyvinyl alcohol is obtained by saponifying polyvinyl acetate. Examples of the polyvinyl alcohol-based resin include a saponified product of a copolymer of vinyl acetate and a monomer having copolymerizability. When the copolymerizable monomer is ethylene, an ethylene-vinyl alcohol copolymer is obtained. Examples of the copolymerizable monomer include unsaturated carboxylic acids such as (anhydrous) maleic acid, fumaric acid, crotonic acid, itaconic acid, (meth) acrylic acid, and esters thereof; ethylene, propylene, and the like. α-olefin, (meth) allylsulfonic acid (soda), sulfonic acid soda (monoalkylmalate), disulfonic acid soda alkylmalate, N-methylolacrylamide, acrylamide alkylsulfonic acid alkali salt, N-vinylpyrrolidone, N- Examples include vinyl pyrrolidone derivatives. These polyvinyl alcohol resins can be used alone or in combination of two or more. Polyvinyl alcohol obtained by saponifying polyvinyl acetate is preferable from the viewpoint of satisfying moisture heat resistance and water resistance by controlling the heat of crystal fusion of the anchor coat layer to 30 mj / mg or more.

  The saponification degree of the polyvinyl alcohol-based resin can be, for example, 95 mol% or more. From the viewpoint of satisfying the heat and moisture resistance and water resistance, the saponification degree is preferably 96 mol% or more, 99 Mole% or more is preferable, and 99.5 mol% or more is more preferable. The degree of saponification represents the proportion of units that are actually saponified to vinyl alcohol units among the units that can be converted to vinyl alcohol units by saponification, and the residue is a vinyl ester unit. The saponification degree can be determined according to JIS K 6726-1994.

  The average degree of polymerization of the polyvinyl alcohol-based resin can be, for example, 500 or more. From the viewpoint of satisfying the heat resistance and water resistance of the anchor coat layer, the average degree of polymerization is preferably 1000 or more. Further, 1500 or more is preferable, and 2000 or more is more preferable. The average degree of polymerization of the polyvinyl alcohol resin is measured according to JIS-K6726.

  Moreover, as said polyvinyl alcohol-type resin, the modified polyvinyl alcohol-type resin which has a hydrophilic functional group in the side chain of the said polyvinyl alcohol or its copolymer can be used. Examples of the hydrophilic functional group include an acetoacetyl group and a carbonyl group. In addition, modified polyvinyl alcohol obtained by acetalization, urethanization, etherification, grafting, phosphoric esterification or the like of a polyvinyl alcohol resin can be used.

  As the polyurethane resin, an emulsion of polyurethane resin can be used. As the polyurethane resin emulsion, a self-emulsified one without using an emulsifier can be used.

  As the polyurethane resin, for example, a one-pack type resin obtained by polyaddition reaction of a polymer polyol and an isocyanate compound can be used. As the one-component polyurethane resin, for example, a polyether polyurethane resin, a polyester polyurethane resin, or the like can be used. As the polyurethane resin, those in which hydroxyl groups remain are preferable. Specifically, for example, a lacquer type polyurethane resin can be used. The polyurethane resin can form a film by simply removing the solvent and water by drying.

  The polyether-based polyurethane resin is generally obtained by a polyaddition reaction of a polyether polyol and an isocyanate compound. The polyether polyol is obtained by adding alkylene oxide to one or more polyhydric alcohols by ring-opening polymerization. A polyester polyurethane resin is generally obtained by a polyaddition reaction of a polyester polyol and an isocyanate compound. The polyesterol polyol is obtained by polycondensation of a polyhydric alcohol and a polybasic acid. In addition, the polymer polyol such as polyether polyol or polyether polyol preferably has a number average molecular weight of 400 to 3000, and more preferably 500 to 2000. Polymer polyols such as polyether polyols and polyester polyols may be used singly or may be a copolymer using two or more.

  As the isocyanate compound, aromatic, araliphatic, aliphatic, or alicyclic isocyanates usually used for polyurethane can be used as appropriate. As the isocyanate compound, adducts, dimers, trimers, and polymers of the above isocyanate compounds may be used. Furthermore, as the isocyanate compound, a modified isocyanate obtained by urethanizing, uretidione-forming, or carbodiimidizing a part of the above-mentioned isocyanate can also be used.

  When the polyurethane resin is dispersed in water, a method is known in which the resin is forcibly emulsified and dispersed using an emulsifier. Further, a self-emulsified product obtained by introducing an anionic group, a cationic group or a nonionic group of a water-dispersible hydrophilic group into the resin can be used. Moreover, an ionic polymer complex can be used.

  Examples of the polyurethane resin emulsion include Adeka Bon titer HUX series manufactured by Asahi Denka Kogyo Co., Ltd., which is self-emulsified without using an emulsifier. Specific examples of the water-based urethane resin include Superflex series manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Takelac W-6020 manufactured by Mitsui Chemicals Polyurethanes, and the like.

  An epoxy resin emulsion can be used as the epoxy resin. In the case of dispersing the epoxy resin in water, a method is known in which the resin is forcibly emulsified and dispersed using an emulsifier. Examples of the epoxy resin include Adeka Resin EM series manufactured by ADEKA Corporation, Celoxide 2021P manufactured by Daicel Corporation, and the like.

  Examples of the oxazoline group-containing polymer include polymers having a main chain composed of an acrylic skeleton or a styrene skeleton, and having an oxazoline group in the side chain of the main chain. Among these, an oxazoline group-containing acrylic polymer having a main chain composed of an acrylic skeleton and having an oxazoline group in the side chain of the main chain is preferable.

  Examples of the oxazoline group include a 2-oxazoline group, a 3-oxazoline group, and a 4-oxazoline group, and among these, a 2-oxazoline group is preferable. The 2-oxazoline group is generally represented by the following general formula (1).

（式中、Ｒ^１〜Ｒ^４は、それぞれ独立に、水素原子、ハロゲン原子、アルキル基、アラルキル基、フェニル基、又は、置換フェニル基を示す。）

^(Wherein, R 1 to R ⁴ are each independently a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, a phenyl group, or a substituted phenyl group.)

  The oxazoline group-containing polymer may have a polyoxyalkylene group in addition to the oxazoline group.

  The number average molecular weight of the oxazoline group-containing polymer is preferably 5,000 or more, more preferably 10,000 or more, and usually 1,000,000 or less. If the number average molecular weight is lower than 5,000, the anchor layer may have insufficient strength, causing cohesive failure, and the anchoring force may not be improved. When the number average molecular weight is higher than 1,000,000, workability may be inferior. The oxazoline group-containing polymer has an oxazoline value of, for example, 1,500 g solid / eq. Or less, preferably 1,200 g solid / eq. The following is more preferable. The oxazoline value is 1,500 g solid / eq. If it is larger, the amount of the oxazoline group contained in the molecule decreases, and the anchoring force may not be improved.

  Since the oxazoline group-containing polymer reacts with the hydroxyl group contained in the pressure-sensitive adhesive composition at a relatively low temperature, the functional group in the pressure-sensitive adhesive layer can be obtained by including the oxazoline group-containing polymer in the anchor coat layer. It can react with and adhere tightly.

  Specific examples of the oxazoline group-containing polymer include oxazoline group-containing acrylic polymers such as Epochros WS-300, Epocros WS-500, and Epocros WS-700 manufactured by Nippon Shokubai Co., Ltd., for example, manufactured by Nippon Shokubai Co., Ltd. Examples include oxazoline group-containing acrylic / styrene-based polymers such as Epocros K-1000 series and Epocros K-2000 series, which can be used alone or in combination of two or more.

  The anchor coat layer of the present invention is formed from a water-based resin composition containing the water-based resin as a main component. The water-based resin composition has a primary alcohol capable of reacting with a hydroxyl group at the molecular end. It contains at least one compound (a). Reaction of the mercapto group-containing silane coupling agent and the hydroxyl group-containing base polymer in the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer as described above by introducing the compound (a) into the anchor coat layer Advances and the anchoring force between the anchor coat layer and the pressure-sensitive adhesive layer can be improved.

  The aqueous resin preferably does not have a functional group having reactivity with the primary alcohol capable of reacting with the hydroxyl group of the compound (a), and among the exemplified aqueous resins, the polyvinyl alcohol resin In particular, unmodified polyvinyl alcohol resin is preferably used. Alternatively, when an unmodified polyvinyl alcohol resin is used, the hydrophilic functional group related to the modification is an adhesive in relation to a primary alcohol that can react with the hydroxyl group of the compound (a). Those having lower reactivity than the functional group (silanol group) of the mercapto group-containing silane coupling agent in the agent composition are preferred.

  The compound (a) is preferably blended at a ratio of, for example, 0.2 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the aqueous resin. The ratio of the compound (a) is preferably 0.2 parts by weight or more for improving the anchoring force. The proportion of the compound (a) is preferably 1 part by weight or more, and more preferably 3 parts by weight or more. On the other hand, when the proportion of the compound (a) is increased, water resistance and appearance (appearance that is confirmed as unevenness in the polarizing film) deteriorates, so the proportion of the compound (a) is 20 parts by weight or less. It is preferably 10 parts by weight or less, more preferably 7 parts by weight or less. The ratio of the compound (a) is determined by the type of the hydroxyl group-containing base polymer and mercapto group-containing silane coupling agent used in the pressure-sensitive adhesive composition.

  The proportion of the aqueous resin in the anchor coat layer or the aqueous resin composition (solid content) is preferably 80% by weight or more, more preferably 90% by weight or more, and further preferably 95% by weight or more.

  As the compound (a), a compound having at least one primary alcohol at the molecular end can be suitably used. Examples of the compound include methylol urea, methylol melamine, amino-formaldehyde resin such as condensate of alkylated methylol urea and formaldehyde, ethylene glycol, glycerin, 1,6-hexanediol, 1,8-octanediol, fat Group alcohol and polyethylene glycol. Among these, an amino-formaldehyde resin having a methylol group, particularly, methylol melamine is preferable.

  Moreover, the compound which has a functional group which can react with hydroxyl groups other than the said compound (a) can be used. For example, a compound having an amino group at the molecular end can be mentioned. Examples of the compound include alkylene diamines having two alkylene groups and two amino groups such as ethylene diamine, triethylene diamine, and hexamethylene diamine; hydrazine; adipic acid dihydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, and glutaric acid. Dihydrazides such as dihydrazide, isophthalic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide; ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine, butylene-1,4 -Water-soluble dihydrazines such as dihydrazine. Of these, hydrazine is preferred. For example, when the base polymer of the pressure-sensitive adhesive composition has a hydroxyl group (when the base polymer is a (meth) acrylic polymer, the monomer unit contains a hydroxyl group-containing monomer as a monomer unit). It is suitable for

  Furthermore, as the compound having a functional group capable of reacting with a hydroxyl group other than the compound (a), for example, tolylene diisocyanate, hydrogenated tolylene diisocyanate, trimethylolpropane tolylene diisocyanate adduct, triphenylmethane triisocyanate, Methylene bis (4-phenylmethane triisocyanate, isophorone diisocyanate and isocyanates such as ketoxime block product or phenol block product thereof; ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin di or triglycidyl ether, 1,6- Hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diglycidyl amide Epoxys such as: Monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde; Dialdehydes such as glyoxal, malondialdehyde, succindialdehyde, glutardialdehyde, maleindialdehyde, phthaldialdehyde; alkylated methylol Amino-formaldehyde resins such as melamine fluoride, acetoguanamine, condensates of benzoguanamine and formaldehyde; further divalent metals such as sodium, potassium, magnesium, calcium, aluminum, iron, nickel, or salts of trivalent metals and their oxides Of these, amino-formaldehyde resins and water-soluble dihydrazines are preferred.

  The compound having a functional group capable of reacting with a hydroxyl group other than the compound (a) can be used from the viewpoint of improving water resistance and controlling the elastic modulus, and the ratio is based on 100 parts by weight of the aqueous resin. 20 parts by weight or less, preferably 10 parts by weight or less, and more preferably 5 parts by weight or less.

  The aqueous resin composition is prepared as a solution in which the aqueous resin is dissolved in a solvent. Examples of the solvent include water, dimethyl sulfoxide, dimethylformamide, and dimethylacetamide N-methylpyrrolidone. These may be used alone or in combination of two or more. Among these, it is preferable to use it as an aqueous solution using water as a solvent. The concentration of the water-based resin in the water-based resin composition (for example, an aqueous solution) is not particularly limited, but is 0.1 to 15% by weight, preferably 0.5, in view of coating property and storage stability. -10% by weight.

  In addition, things other than the said compound (a) may be added to the said aqueous resin composition (for example, aqueous solution). For example, surfactant etc. are mentioned. Examples of the surfactant include nonionic surfactants. Furthermore, stabilizers such as various tackifiers, ultraviolet absorbers, antioxidants, heat stabilizers and hydrolysis stabilizers can be blended.

  The thickness of the anchor coat layer is preferably 0.05 μm, more preferably 0.2 μm or more, and the thickness of the anchor coat layer is preferably 0.5 μm or more. It is preferably 7 μm or more. In particular, when a polyvinyl alcohol-based resin is used as the water-based resin, the anchor coat layer preferably has a thickness of 0.2 μm or more, and the anchor coat layer having the thickness generates cracks due to thermal shock. Can be suppressed. On the other hand, if the anchor coat layer becomes too thick, the optical reliability and water resistance deteriorate. Therefore, the thickness of the anchor coat layer is preferably 6 μm or less, more preferably 5 μm or less, further 3 μm or less, and further 2 μm or less. Is preferred.

  The anchor coat layer can be formed by applying and drying the aqueous resin composition on the other surface of the polarizer (the surface not having the protective film). The aqueous resin composition is applied so as to have a thickness after drying (preferably 0.2 μm to 6 μm). The application operation is not particularly limited, and any appropriate method can be adopted. For example, various means such as a roll coating method, a spin coating method, a wire bar coating method, a dip coating method, a die coating method, a curtain coating method, a spray coating method, a knife coating method (comma coating method, etc.) can be employed.

<Adhesive layer>
The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing a base polymer having a hydroxyl group and a mercapto group-containing silane coupling agent. For the formation of the pressure-sensitive adhesive layer, an appropriate pressure-sensitive adhesive having a hydroxyl group can be used, and the type thereof is not particularly limited. Adhesives include rubber adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinyl pyrrolidone adhesives, polyacrylamide adhesives, Cellulose-based adhesives and the like can be mentioned. Various base polymers can be used according to these pressure-sensitive adhesives.

  The ratio of the base polymer having a hydroxyl group in the pressure-sensitive adhesive layer or pressure-sensitive adhesive composition (solid content) is preferably 80% by weight or more, more preferably 90% by weight or more, and further 95% by weight. The above is preferable.

  Among these pressure-sensitive adhesives, those having excellent optical transparency, suitable wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and excellent weather resistance and heat resistance are preferably used. An acrylic pressure-sensitive adhesive is preferably used as one exhibiting such characteristics. A (meth) acrylic polymer is used as the base polymer of the acrylic pressure-sensitive adhesive. The (meth) acrylic polymer usually contains an alkyl (meth) acrylate as a main component as a monomer unit. (Meth) acrylate refers to acrylate and / or methacrylate, and (meth) of the present invention has the same meaning.

  Examples of the alkyl (meth) acrylate constituting the main skeleton of the (meth) acrylic polymer include linear or branched alkyl groups having 1 to 18 carbon atoms. For example, the alkyl group includes methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, amyl group, hexyl group, cyclohexyl group, heptyl group, 2-ethylhexyl group, isooctyl group, nonyl group, decyl group. Group, isodecyl group, dodecyl group, isomyristyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, and the like. These can be used alone or in combination. The average carbon number of these alkyl groups is preferably 3-9.

  The (meth) acrylic polymer used in the present invention preferably contains a hydroxyl group-containing monomer as a monomer unit. The hydroxyl group-containing monomer has a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, and has a hydroxyl group. Specific examples of the hydroxyl group-containing monomer include, for example, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxy (meth) acrylate. Hexyl, (meth) acrylic acid 8-hydroxyoctyl, (meth) acrylic acid 10-hydroxydecyl, (meth) acrylic acid 12-hydroxylauryl, (meth) acrylic acid hydroxyalkyl and (4-hydroxymethylcyclohexyl)- Examples include methyl acrylate.

  The (meth) acrylic polymer is mainly composed of alkyl (meth) acrylate in the weight ratio of all constituent monomers, and the ratio of the hydroxyl group-containing monomer in the (meth) acrylic polymer is in the weight ratio of all constituent monomers. 0.01 to 15% is preferable, 0.03 to 10% is more preferable, and 0.05 to 7% is more preferable.

  In addition, the (meth) acrylic polymer has a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group for the purpose of improving adhesiveness and heat resistance. The above copolymerization monomers can be introduced by copolymerization.

  Examples of the copolymerization monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid and other carboxyl group-containing monomers; maleic anhydride Acid anhydride group-containing monomers such as itaconic anhydride; caprolactone adduct of acrylic acid; styrene sulfonic acid and allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, Examples thereof include sulfonic acid group-containing monomers such as sulfopropyl (meth) acrylate and (meth) acryloyloxynaphthalenesulfonic acid; and phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate.

  In addition, (N-substituted) amides such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, etc. Monomer; (meth) acrylic acid aminoethyl, (meth) acrylic acid N, N-dimethylaminoethyl, (meth) acrylic acid t-butylaminoethyl and other (meth) acrylic acid alkylaminoalkyl monomers; (meth) acrylic (Meth) acrylic acid alkoxyalkyl monomers such as methoxyethyl acid and ethoxyethyl (meth) acrylate; N- (meth) acryloyloxymethylenesuccinimide, N- (meth) acryloyl-6-oxyhexamethylenesuccinimide, N- ( (Meta) acryloyl- -Succinimide monomers such as oxyoctamethylene succinimide and N-acryloylmorpholine; Maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide; N-methylitaconimide, N-ethyl Itaconimide monomers such as itaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide, and the like are listed as examples of monomers for modification purposes. It is done.

  Further, as modifying monomers, vinyl acetate, vinyl propionate, N-vinyl pyrrolidone, methyl vinyl pyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperazine, vinyl pyrazine, vinyl pyrrole, vinyl imidazole, vinyl oxazole, vinyl morpholine, N- Vinyl monomers such as vinylcarboxylic acid amides, styrene, α-methylstyrene, N-vinylcaprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; (Meth) acrylic acid polyethylene glycol, (meth) acrylic acid polypropylene glycol, (meth) acrylic acid methoxyethylene glycol, (meth) acrylic acid meth Glycol acrylic ester monomers such as polypropylene glycol; acrylic acid ester monomers such as tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate may also be used. it can. Furthermore, isoprene, butadiene, isobutylene, vinyl ether and the like can be mentioned.

  Furthermore, examples of the copolymerizable monomer other than the above include silane-based monomers containing silicon atoms. Examples of the silane monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, and 8-vinyloctyltrimethoxysilane. , 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane, and the like.

  Moreover, as a copolymerization monomer, tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neodymium Pentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate (Meth) acryloyl such as esterified product of (meth) acrylic acid and polyhydric alcohol such as caprolactone-modified dipentaerythritol hexa (meth) acrylate , Polyfunctional monomers having two or more unsaturated double bonds such as vinyl groups, and unsaturated groups such as (meth) acryloyl groups and vinyl groups as functional groups similar to monomer components in the backbone of polyester, epoxy, urethane, etc. Polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate and the like to which two or more double bonds are added can also be used.

  The ratio of the copolymerization monomer (other than the hydroxyl group-containing monomer) in the (meth) acrylic polymer is not particularly limited, but is about 0 to 20%, about 0.1 to 15% in the weight ratio of all constituent monomers, Furthermore, it is preferable that it is about 0.1 to 10%.

  Among these copolymerizable monomers (other than hydroxyl group-containing monomers), carboxyl group-containing monomers are preferably used from the viewpoint of adhesiveness and durability. When a carboxyl group-containing monomer is contained as a copolymerization monomer, the proportion is preferably 0.05 to 10% by weight, more preferably 0.1 to 8% by weight, and further preferably 0.2 to 6% by weight. .

  As the (meth) acrylic polymer of the present invention, those having a weight average molecular weight in the range of 500,000 to 3,000,000 are usually used. In view of durability, particularly heat resistance, it is preferable to use those having a weight average molecular weight of 700,000 to 2,700,000. Furthermore, it is preferable that it is 800,000-2.5 million. A weight average molecular weight of less than 500,000 is not preferable in terms of heat resistance. On the other hand, if the weight average molecular weight is more than 3 million, a large amount of dilution solvent is required to adjust the viscosity for coating, which is not preferable. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

  The production of such a (meth) acrylic polymer can be appropriately selected from known production methods such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations. Further, the (meth) acrylic polymer obtained may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

  The polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited and can be appropriately selected and used. In addition, the weight average molecular weight of a (meth) acrylic-type polymer can be controlled by the usage-amount of a polymerization initiator and a chain transfer agent, and reaction conditions, The usage-amount is suitably adjusted according to these kinds.

  Furthermore, the pressure-sensitive adhesive composition of the present invention contains a mercapto group-containing silane coupling agent in addition to the hydroxyl group-containing base polymer (for example, (meth) acrylic polymer). Examples of the mercapto group-containing silane coupling agent include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldiethoxysilane, and β-mercaptomethylphenylethyl. Examples include compounds having a mercapto group such as trimethoxysilane, mercaptomethyltrimethoxysilane, 6-mercaptohexyltrimethoxysilane, and 10-mercaptodecyltrimethoxysilane.

  As the mercapto group-containing silane coupling agent, an oligomer type mercapto group-containing silane coupling agent having two or more alkoxysilyl groups in the molecule is preferable. Specific examples include X-41-1805, X-41-1818, and X-41-1810 manufactured by Shin-Etsu Chemical Co., Ltd. These mercapto group-containing silane coupling agents are preferred because they are less likely to volatilize and are effective in improving durability because they have a plurality of alkoxysilyl groups. Here, the oligomer type refers to a polymer of a monomer dimer or more and less than about 100 mer, and the weight average molecular weight of the oligomer type silane coupling agent is preferably about 300 to 30000.

  The number of alkoxysilyl groups in the oligomer type mercapto group-containing silane coupling agent may be two or more in the molecule, and the number is not limited. The amount of the alkoxy group in the oligomer type mercapto group-containing silane coupling agent is preferably 10 to 60% by weight, more preferably 20 to 50% by weight in the silane coupling agent, and more preferably 20 to 40%. More preferably, it is% by weight.

  Although the kind of alkoxy group is not limited, For example, C1-C6 alkoxy groups, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, can be mentioned. Among these, methoxy and ethoxy are preferable, and methoxy is more preferable. It is also preferred that both methoxy and ethoxy are contained in one molecule.

  The mercapto group content of the mercapto group-containing silane coupling agent is preferably, for example, a mercapto equivalent of 1000 g / mol or less, more preferably 800 g / mol or less in the case of a mercapto group (-SH). More preferably, it is 500 g / mol or less. Moreover, the lower limit of the mercapto equivalent is not particularly limited, but for example, it is preferably 200 g / mol or more.

  The mercapto group-containing silane coupling agent may be used alone, or may be used in combination of two or more, but the total content is a base polymer having the hydroxyl group (for example, (Meth) acrylic polymer) 0.001 to 5 parts by weight, preferably 0.01 to 3 parts by weight, more preferably 0.02 to 2 parts by weight, and more preferably 0.05 to 1 part per 100 parts by weight. Part by weight is particularly preferred.

  Moreover, silane coupling agents other than the said mercapto group containing silane coupling agent can also be added to the adhesive composition of this invention. Other coupling agents include 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) Amino group-containing silane coupling agents such as propylamine and N-phenyl-γ-aminopropyltrimethoxysilane, (meth) acryl group-containing silanes such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane Examples thereof include coupling agents and isocyanate group-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane.

  Silane coupling agents other than the mercapto group-containing silane coupling agent can be added within a range that does not impair the effects of the present invention, and the amount used is not particularly limited. From the viewpoint of adhesion, it can be used in the range of 3 parts by weight or less, more preferably 2 parts by weight or less, and further in the range of 1 part by weight or less with respect to 100 parts by weight of the pressure-sensitive adhesive composition. . Adhesion can be improved by using a silane coupling agent other than a mercapto group. However, since a silane coupling agent other than a mercapto group can also impart reworkability, the adhesion tends to deteriorate if the amount added is large.

  Furthermore, the pressure-sensitive adhesive composition of the present invention can contain a crosslinking agent. The crosslinking agent may be used alone or in combination of two or more. The content of the crosslinking agent as a whole is preferably 2 parts by weight or less, more preferably 1.5 parts by weight or less, and further preferably 1 part by weight with respect to 100 parts by weight of the base polymer having a hydroxyl group. The following is preferred.

  In the adhesive composition of this invention, it is preferable to contain the crosslinking agent (b) which does not react with a hydroxyl group as said crosslinking agent. The crosslinking agent (b) that does not react with the hydroxyl group can be used in combination with an isocyanate crosslinking agent, but is suitable in an embodiment that does not contain an isocyanate crosslinking agent. When the pressure-sensitive adhesive composition of the present invention does not contain an isocyanate-based crosslinking agent, there is no problem in handling regarding pot life. The crosslinking agent (b) that does not react with the hydroxyl group does not particularly require aging until the predetermined gel fraction is reached after formation of the pressure-sensitive adhesive layer, and the gel fraction 80 from the initial stage when the pressure-sensitive adhesive layer is formed is 80%. % Hard material can be produced. Furthermore, since the crosslinking with the crosslinking agent (b) that does not react with the hydroxyl group is proceeding in the pressure-sensitive adhesive layer, the hydroxyl group of the base polymer must efficiently react with the silanol group of the mercapto group-containing silane coupling agent. It is considered that the gel fraction of the pressure-sensitive adhesive layer can be hardened to 80% or more from the initial stage.

  The crosslinking agent (b) may be used singly or as a mixture of two or more, but the total content is 100 parts by weight of the base polymer having a hydroxyl group. The crosslinking agent (b) is preferably 0.01 to 2 parts by weight, more preferably 0.04 to 1.5 parts by weight, further preferably 0.05 to 1 part by weight, More preferably, it is 0.4 to 0.6 parts by weight. In order to adjust processability, reworkability, cross-linking stability, peelability, and the like, it is appropriately selected within this range.

  As the crosslinking agent (b), a peroxide can be preferably used.

  In addition, as a measuring method of the peroxide decomposition amount which remained after the reaction process, it can measure by HPLC (high performance liquid chromatography), for example.

  More specifically, for example, about 0.2 g of the pressure-sensitive adhesive composition after the reaction treatment is taken out, immersed in 10 ml of ethyl acetate, extracted by shaking at 25 ° C. and 120 rpm for 3 hours with a shaker, and then at room temperature. Leave for 3 days. Next, 10 ml of acetonitrile was added, shaken at 120 rpm at 25 ° C. for 30 minutes, and about 10 μl of the extract obtained by filtration through a membrane filter (0.45 μm) was injected into the HPLC for analysis. The amount of peroxide can be set.

  As the peroxide, any radical active species can be used as long as it generates radical active species by heating or light irradiation to advance the crosslinking of the base polymer of the pressure-sensitive adhesive composition. However, in consideration of workability and stability. It is preferable to use a peroxide having a one-minute half-life temperature of 80 ° C. to 160 ° C., and more preferable to use a peroxide having a 90 ° C. to 140 ° C.

  Examples of peroxides that can be used include di (2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature: 90.6 ° C.), 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 0.5 ° 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.), 1,1,3,3-tetramethylbutyl Oxy-2-ethylhexanoate (1 minute half-life temperature: 124.3 ° C), di (4-methylbenzoyl) peroxide (1 minute half-life temperature: 128.2 ° C), dibenzoyl peroxide (half-minute for 1 minute) Period temperature: 130.0 ° C.), t-butyl peroxyisobutyrate (1 minute half-life temperature: 136.1 ° C.), 1,1-di (t-hexylperoxy) cyclohexane (1 minute half-life temperature: 149.2 ° C.). Especially, since the crosslinking reaction efficiency is excellent, di (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.

  The peroxide half-life is an index representing the decomposition rate of the peroxide, and means the time until the remaining amount of peroxide is reduced to half. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in the manufacturer catalog, for example, “Organic peroxide catalog 9th edition by Nippon Oil & Fats Co., Ltd.” (May 2003) ".

  As a crosslinking agent other than the crosslinking agent (b), an organic crosslinking agent or a polyfunctional metal chelate can be used. Examples of the organic crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, and an imine crosslinking agent. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. Can be mentioned. Examples of the atom in the organic compound that is covalently bonded or coordinated include an oxygen atom, and examples of the organic compound include an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, and a ketone compound.

  The amount of the crosslinking agent other than the crosslinking agent (b) is preferably controlled so that a hard material having a gel fraction of 80% or more from the initial stage of forming the pressure-sensitive adhesive layer can be produced. For example, the crosslinking agent other than the crosslinking agent (b) can be used in a range of 2 parts by weight or less, more preferably 1 part by weight or less, and further 0.5 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive composition. It can be included in the following ranges. In particular, when an isocyanate-based crosslinking agent is used as a crosslinking agent other than the crosslinking agent (b), the amount used is controlled within a range that does not require aging. Isocyanate-based crosslinking agents are preferable from the viewpoint of securing anchoring force to an adherend such as a film, and are also preferable from the viewpoint of suppressing the dimensional change of the polarizing film because the pressure-sensitive adhesive layer becomes hard. Furthermore, it is particularly preferable to use an isocyanate cross-linking agent and a cross-linking agent (b) that does not react with a hydroxyl group in combination because a stronger anchoring force can be obtained.

  Furthermore, the pressure-sensitive adhesive composition of the present invention may contain an alkali metal salt, a polyether-modified silicone compound, and other known additives. For example, a polyether compound of polyalkylene glycol such as polypropylene glycol, coloring Powders, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, UV absorbers, polymerization prohibited An agent, an inorganic or organic filler, a metal powder, a particulate shape, a foil-like material, and the like can be appropriately added depending on the use. Moreover, you may employ | adopt the redox system which added a reducing agent within the controllable range.

  The pressure-sensitive adhesive composition forms a pressure-sensitive adhesive layer. In forming the pressure-sensitive adhesive layer, it is necessary to fully consider the influence of the crosslinking treatment temperature and the crosslinking treatment time as well as adjusting the addition amount of the entire crosslinking agent. preferable.

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

  Moreover, this crosslinking process may be performed at the temperature at the time of the drying process of an adhesive layer, and you may carry out by providing a crosslinking process process separately after a drying process.

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

  As a method for forming the pressure-sensitive adhesive layer, for example, the pressure-sensitive adhesive composition is applied to a release-processed separator and the like, and after forming a pressure-sensitive adhesive layer by drying and removing a polymerization solvent or the like, in the embodiment of FIGS. 1 or 2, in the embodiment shown in FIGS. 1 and 2, the adhesive composition is applied to the anchor coat layer, and the polymerization solvent is dried and removed to form the adhesive layer on a polarizing film. The In applying the pressure-sensitive adhesive, one or more solvents other than the polymerization solvent may be added as appropriate.

  As the release-treated separator, a silicone release liner is preferably used. In the step of applying the pressure-sensitive adhesive composition of the present invention onto such a liner and drying to form the pressure-sensitive adhesive layer, the method of drying the pressure-sensitive adhesive composition can be appropriately determined depending on the purpose. Can be employed. Preferably, a method of heating and drying the coating film is used. The heat drying temperature is preferably 40 ° C to 200 ° C, more preferably 50 ° C to 180 ° C, and particularly preferably 70 ° C to 170 ° C. By setting the heating temperature in the above range, an adhesive layer having excellent adhesive properties can be obtained.

  As the drying time, an appropriate time can be adopted 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.

  Various methods are used as a method of forming the pressure-sensitive adhesive layer. Specifically, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples thereof include an extrusion coating method.

  The thickness in particular of an adhesive layer is not restrict | limited, For example, it is about 1-100 micrometers. Preferably, it is 2-50 micrometers, More preferably, it is 2-40 micrometers, More preferably, it is 5-35 micrometers.

  When the pressure-sensitive adhesive layer is exposed, the pressure-sensitive adhesive layer may be protected with a sheet (separator) that has been subjected to a release treatment until practical use.

  Examples of the constituent material of the separator include, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and laminates thereof. Although a thin leaf body etc. can be mentioned, a plastic film is used suitably from the point which is excellent in surface smoothness.

  The plastic film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer. For example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, and a vinyl chloride co-polymer are used. Examples thereof include a polymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

  The thickness of the separator is usually 5 to 200 μm, preferably about 5 to 100 μm. For the separator, if necessary, mold release and antifouling treatment with a silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, silica powder, etc., coating type, kneading type, vapor deposition type It is also possible to carry out antistatic treatment such as. In particular, the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the separator.

  In addition, the sheet | seat which carried out the peeling process used in preparation of said polarizing film with an adhesive layer can be used as a separator of a polarizing film with an adhesive layer as it is, and can simplify in the surface of a process.

<Surface protection film>
A surface protective film can be provided in the polarizing film with an adhesive layer. The surface protective film usually has a base film and an adhesive layer, and protects the polarizer via the adhesive layer.

  As the base film of the surface protective film, a film material having isotropic property or close to isotropic property is selected from the viewpoints of inspection property and manageability. Examples of film materials include polyester resins such as polyethylene terephthalate film, cellulose resins, acetate resins, polyether sulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, acrylic resins, and the like. Examples thereof include transparent polymers such as resins. Of these, polyester resins are preferred. The base film can be used as a laminate of one kind or two or more kinds of film materials, and a stretched product of the film can also be used. The thickness of the base film is generally 500 μm or less, preferably 10 to 200 μm.

  The pressure-sensitive adhesive that forms the pressure-sensitive adhesive layer of the surface protective film includes a (meth) acrylic polymer, a silicone-based polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based or a rubber-based pressure-sensitive adhesive. Can be appropriately selected and used. From the viewpoints of transparency, weather resistance, heat resistance and the like, an acrylic pressure-sensitive adhesive having an acrylic polymer as a base polymer is preferable. The thickness (dry film thickness) of the pressure-sensitive adhesive layer is determined according to the required adhesive force. Usually, it is about 1-100 micrometers, Preferably it is 5-50 micrometers.

  The surface protective film can be provided with a release treatment layer on the surface opposite to the surface on which the pressure-sensitive adhesive layer is provided on the base film, using a low adhesion material such as silicone treatment, long-chain alkyl treatment, or fluorine treatment. .

<Other optical layers>
The polarizing film with a pressure-sensitive adhesive layer of the present invention can be used as an optical film laminated with another optical layer in practical use. The optical layer is not particularly limited. For example, for forming a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including wavelength plates such as 1/2 and 1/4), and a viewing angle compensation film. One or more optical layers that may be used can be used. In particular, a reflective polarizing film or a semi-transmissive polarizing film in which a polarizing plate with a pressure-sensitive adhesive layer of the present invention is further laminated with a reflective plate or a semi-transmissive reflective plate, and an elliptically polarized light in which a retardation film is further laminated with a polarizing film. A film, a circularly polarizing film, a wide viewing angle polarizing film in which a viewing angle compensation film is further laminated on the polarizing film, or a polarizing film in which a brightness enhancement film is further laminated on the polarizing film are preferable.

  An optical film obtained by laminating the above optical layer on a polarizing film with a pressure-sensitive adhesive layer can also be formed by sequentially laminating separately in the manufacturing process of a liquid crystal display device, etc. Is excellent in quality stability and assembly work, and has the advantage of improving the manufacturing process of liquid crystal display devices and the like. For the lamination, an appropriate adhesive means such as a pressure-sensitive adhesive layer can be used. When adhering the polarizing film with the pressure-sensitive adhesive layer and other optical films, their optical axes can be arranged at an appropriate angle depending on the intended retardation characteristics and the like.

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

  An appropriate liquid crystal display device such as a liquid crystal display device in which a polarizing film with an adhesive layer or an optical film is disposed on one side or both sides of a liquid crystal cell, or a backlight or a reflecting plate used in an illumination system can be formed. In that case, the polarizing film with a pressure-sensitive adhesive layer or the optical film according to the present invention can be installed on one side or both sides of the liquid crystal cell. When providing a polarizing film with an adhesive layer or an optical film on both sides, they may be the same or different. Further, when forming a liquid crystal display device, for example, a single layer or a suitable part such as a diffusing plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusing plate, a backlight, etc. Two or more layers can be arranged.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to the examples shown below. In addition, all the parts and% in each example are based on weight. The room temperature standing conditions not specifically defined below are all 23 ° C. and 65% RH.

<Measurement of weight average molecular weight of (meth) acrylic polymer>
The weight average molecular weight of the (meth) acrylic polymer was measured by GPC (gel permeation chromatography).
・ Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
Column: manufactured by Tosoh Corporation, G7000H _XL + GMH _XL + GMH _XL
・ Column size: 7.8mmφ × 30cm each 90cm in total
-Column temperature: 40 ° C
・ Flow rate: 0.8ml / min
・ Injection volume: 100 μl
・ Eluent: Tetrahydrofuran ・ Detector: Differential refractometer (RI)
Standard sample: polystyrene

<Production of polarizer>
One side of an amorphous isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film (thickness: 100 μm) having a water absorption of 0.75% and Tg of 75 ° C. is subjected to corona treatment. Alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (polymerization degree 1200, acetoacetyl modification degree 4.6%, saponification degree 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd. An aqueous solution containing 9: 1 ratio of the trade name “Gosefimer Z200”) was applied and dried at 25 ° C. to form a PVA-based resin layer having a thickness of 11 μm, thereby preparing a laminate.
The obtained laminate was uniaxially stretched in the longitudinal direction (longitudinal direction) 2.0 times between rolls having different peripheral speeds in an oven at 120 ° C. (air-assisted stretching process).
Next, the laminate was immersed in an insolubilization bath (a boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with respect to 100 parts by weight of water) for 30 seconds (insolubilization treatment).
Subsequently, it was immersed in a dyeing bath having a liquid temperature of 30 ° C. while adjusting the iodine concentration and the immersion time so that the polarizing plate had a predetermined transmittance. In this example, 0.2 parts by weight of iodine was blended with 100 parts by weight of water, and immersed in an aqueous iodine solution obtained by blending 1.0 part by weight of potassium iodide (dyeing treatment). .
Subsequently, it was immersed for 30 seconds in a crosslinking bath having a liquid temperature of 30 ° C. (a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with respect to 100 parts by weight of water). (Crosslinking treatment).
Thereafter, the laminate was immersed in a boric acid aqueous solution (an aqueous solution obtained by blending 4 parts by weight of boric acid and 5 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 70 ° C. However, uniaxial stretching was performed between rolls having different peripheral speeds in the longitudinal direction (longitudinal direction) so that the total stretching ratio was 5.5 times (in-water stretching treatment).
Thereafter, the laminate was immersed in a cleaning bath (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 30 ° C. (cleaning treatment).
As a result, an optical film laminate including a polarizer having a thickness of 5 μm was obtained.

(Preparation of protective film)
Protective film: A (meth) acrylic resin film having a lactone ring structure with a thickness of 40 μm was subjected to corona treatment on the easy adhesion treated surface.

(Production of adhesive to be applied to protective film)
40 parts by weight of N-hydroxyethylacrylamide (HEAA), 60 parts by weight of acryloylmorpholine (ACMO) and 3 parts by weight of a photoinitiator “IRGACURE 819” (manufactured by BASF) were mixed to prepare an ultraviolet curable adhesive.

<Production of single-protective polarizing film>
After applying the protective film on the surface of the polarizing film of the optical film laminate, applying the ultraviolet curable adhesive so that the thickness of the adhesive layer after curing is 0.5 μm, the active energy is applied. As a line, ultraviolet rays were irradiated to cure the adhesive. Ultraviolet irradiation is performed using a gallium-filled metal halide lamp, an irradiation device: Fusion UV Systems, Inc. Light HAMMER 10, Inc., bulb: V bulb, peak illuminance: 1600 mW / cm ² , integrated irradiation amount 1000 / mJ / cm ² (wavelength 380 to 440 nm) ), And the illuminance of ultraviolet rays was measured using a Sola-Check system manufactured by Solatell. Subsequently, the amorphous PET base material was peeled off to produce a piece protective polarizing film A using a thin polarizing film. The optical properties of the obtained piece-protecting polarizing film were a transmittance of 42.8% and a degree of polarization of 99.99%.

<Forming material for anchor coat layer: polyvinyl alcohol-based resin composition>
100 parts of a polyvinyl alcohol resin having a polymerization degree of 2500 and a saponification degree of 99.7 mol% and 5 parts of methylol melamine (trade name “Watersol: S-695”, manufactured by DIC Corporation) were dissolved in pure water to obtain a solid content. An aqueous solution having a concentration of 4% by weight was prepared.

<Preparation of acrylic polymer>
A monomer mixture containing 99 parts of butyl acrylate and 1 part of 2-hydroxyethyl acrylate was charged into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser. Furthermore, 0.1 part of 2,2′-azobisisobutyronitrile as a polymerization initiator was charged with ethyl acetate to 100 parts of the monomer mixture (solid content), and nitrogen gas was introduced while gently stirring. Then, the temperature of the liquid in the flask was kept at around 60 ° C., and a polymerization reaction was carried out for 7 hours. Then, ethyl acetate was added to the resulting reaction solution to prepare a solution of an acrylic polymer having a weight average molecular weight of 1,400,000 adjusted to a solid content concentration of 30%.

(Preparation of adhesive composition)
An oligomeric mercapto group-containing silane coupling agent (alkoxy group amount: 30% by weight, mercapto equivalent: 450 g / mol, X-manufactured by Shin-Etsu Chemical Co., Ltd.) with respect to 100 parts of the solid content of the acrylic polymer solution. 41-1810) 0.2 part and 0.42 part of dibenzoyl peroxide were blended to prepare an acrylic pressure-sensitive adhesive solution.

(Formation of adhesive layer)
Next, the acrylic adhesive solution is uniformly applied to the surface of a polyethylene terephthalate film (separator film) treated with a silicone release agent, and dried for 2 minutes in an air circulation type thermostatic oven at 155 ° C. A pressure-sensitive adhesive layer having a thickness of 20 μm was formed on the surface.

Example 1
<Manufacturing a single protective polarizing film with an anchor coat layer>
The thickness after drying the polyvinyl alcohol-based resin composition adjusted to 25 ° C. on the surface of the polarizing film (polarizer) of the piece protective polarizing film (polarizer surface provided with no protective film) with a wire bar coater. After coating to 1 μm, it was dried with hot air at 90 ° C. for 20 seconds to produce a piece protective polarizing film with an anchor coat layer.

<Preparation of polarizing film with adhesive layer>
Subsequently, the pressure-sensitive adhesive layer formed on the release-treated surface of the release sheet (separator) was bonded to the anchor coat layer formed on the piece protective polarizing film to produce a polarizing film with a pressure-sensitive adhesive layer.

Examples 2-11, Comparative Examples 1-6
In Example 1, the type of aqueous resin to be blended in the anchor coat layer, the blending amount of methylol melamine (the blending part is a value relative to 100 parts of the water based resin), the type of silane coupling agent and crosslinking agent in the pressure-sensitive adhesive composition And a blending amount (the blending part is a value with respect to 100 parts of the acrylic polymer) as shown in Table 1, in the same manner as in Example 1, the piece protective polarizing film with an anchor coat layer and the pressure-sensitive adhesive A polarizing film with a layer was produced.

  The following evaluation was performed about the polarizing film with an adhesive layer obtained by the said Example and comparative example. The results are shown in Table 1.

<Measurement of initial gel fraction>
Sample 1 was prepared by scraping about 0.1 g from the pressure-sensitive adhesive layer formed on the release-treated surface of the separator film within 1 minute. The sample 1 was wrapped in a Teflon (registered trademark) film having a diameter of 0.2 μm (trade name “NTF1122”, manufactured by Nitto Denko Corporation), and then tied with a kite string to obtain a sample 2. The weight of sample 2 before being subjected to the following test was measured, and this was designated as weight A. The weight A is the total weight of the sample 1 (adhesive layer), the Teflon (registered trademark) film, and the kite string. The total weight of the Teflon (registered trademark) film and the kite string was defined as weight B. Next, the sample 2 was put in a 50 ml container filled with ethyl acetate and allowed to stand at 23 ° C. for 1 week. Thereafter, the sample 2 was taken out from the container, dried in a dryer at 130 ° C. for 2 hours to remove ethyl acetate, and the weight of the sample 2 was measured. The weight of Sample 2 after being subjected to the test was measured, and this was designated as weight C. And the gel fraction was computed from the following formula.
Gel fraction (% by weight) = (C−B) / (A−B) × 100
The initial gel fraction of the pressure-sensitive adhesive layer is preferably 80% or more. A low gel fraction leads to defects such as dents remaining easily.

<Throwing power>
The polarizing film with pressure-sensitive adhesive layer obtained in Examples and Comparative Examples was cut into a size of 25 mm × 150 mm, and indium-tin oxide was deposited on the pressure-sensitive adhesive layer surface and the surface of the polyethylene terephthalate film having a thickness of 50 μm. It bonded together so that the vapor deposition surface of a vapor deposition film might contact. Then, after peeling off the edge part of the said polyethylene terephthalate film by hand and confirming that the adhesive layer has adhered to the polyethylene terephthalate film side, 180 degree | times using Shimadzu Corporation tensile tester AG-1 The stress (N / 25 mm) when peeled in the direction at a speed of 300 mm / min was measured (25 ° C.).
An anchoring force of 15 N / 25 mm or more is good because there is no adhesive residue at the time of reworking, no adhesive chipping or adhesive removal at the time of processing. Moreover, the destruction state at the time of peeling is indicated by “cohesive failure (breakage of the anchor coat layer or pressure-sensitive adhesive layer)” or “interfacial peeling (peeling at the interface between the anchor coat layer and the pressure-sensitive adhesive layer)”. In Comparative Example 7, the anchoring force was measured after aging for 48 hours because only the isocyanate-based crosslinking agent was used as the crosslinking agent for the pressure-sensitive adhesive layer. An Example and another comparative example are the values measured within 24 hours (not aging) after producing a polarizing film with an adhesive layer.

In Table 1, peroxides are trade names: Nyper BMT 40SV, benzoyl peroxide, manufactured by NOF Corporation;
Isocyanate is trade name: Takenate D110N, trimethylolpropane adduct of xylylene diisocyanate, manufactured by Mitsui Chemicals, Inc .;
X-41-1810: oligomer type mercapto group-containing silane coupling agent, alkoxy group amount: 30% by weight, mercapto equivalent: 450 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd .;
KBM-802: Monomer-type mercapto group-containing silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd .;
KBM-803: Monomer type mercapto group-containing silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd .;
X-41-1056: oligomer type epoxy group-containing silane coupling agent, alkoxy group amount: 17% by weight, epoxy equivalent: 280 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd .;
Indicates.
The crosslinking agent of Example 10 is a combined system of an isocyanate crosslinking agent and a peroxide crosslinking agent.
Oxazoline group-containing polymer: Epocross WS-700 (manufactured by Nippon Shokubai Co., Ltd.);
Polyurethane resin: Takelac W-6020 (Mitsui Chemical Polyurethane Co., Ltd.);
Epoxy resin: Celoxide 2021P (manufactured by Daicel Corporation);

1 Polarizer 2 Anchor coat layer (Polyvinyl alcohol resin is the main component)
DESCRIPTION OF SYMBOLS 3 Adhesive layer 4 Separator 5, 5 'Protective film 10 Polarizing film with an adhesive layer 11 Polarizing film with an adhesive layer

Claims (18)

A polarizing film with a pressure-sensitive adhesive layer having a polarizer, an anchor coat layer and a pressure-sensitive adhesive layer in this order,
The anchor coat layer is formed from an aqueous resin composition containing an aqueous resin and methylol melamine ,
The said adhesive layer is formed from the adhesive composition containing the base polymer which has a hydroxyl group, and a mercapto group containing silane coupling agent, The polarizing film with an adhesive layer characterized by the above-mentioned.   2. The polarizing film with a pressure-sensitive adhesive layer according to claim 1, wherein the aqueous resin is at least one selected from a polyvinyl alcohol resin, a polyurethane resin, an epoxy resin, and an oxazoline group-containing polymer.   The polarizing film with an adhesive layer according to claim 2, wherein the aqueous resin is a polyvinyl alcohol resin.   4. The polarizing film with a pressure-sensitive adhesive layer according to claim 3, wherein the polyvinyl alcohol-based resin has a saponification degree of 96 mol% or more and an average polymerization degree of 2000 or more. The said water-based resin composition contains 0.2-20 weight part of said methylol melamine with respect to 100 weight part of said water-based resin, The adhesive layer attachment in any one of Claims 1-4 characterized by the above-mentioned. Polarized film. The anchor coat layer, a polarizing film with an adhesive layer according to any one of claims 1 to 5, wherein the thickness is 0.05μm or more 6μm or less. Wherein the base polymer having a hydroxyl group has a hydroxyl group-containing (meth) attached polarizing film adhesive layer according to any one of claims 1 to 6, characterized in that an acrylic polymer. The pressure-sensitive adhesive composition, with respect to 100 parts by weight of the base polymer having a hydroxyl group, according to claim 1-7 where the mercapto group-containing silane coupling agent, characterized in that it contains 0.01 to 5 parts by weight The polarizing film with an adhesive layer in any one. The said adhesive composition contains a crosslinking agent, The polarizing film with an adhesive layer in any one of Claims 1-8 characterized by the above-mentioned. The polarizing film with a pressure-sensitive adhesive layer according to claim 9 , wherein the crosslinking agent contains a crosslinking agent (b) that does not react with a hydroxyl group. The polarizing film with a pressure-sensitive adhesive layer according to claim 9, wherein the crosslinking agent (b) that does not react with the hydroxyl group is a peroxide. The pressure-sensitive adhesive according to claim 10 or 11 , comprising 0.01 to 2 parts by weight of the crosslinking agent (b) that does not react with the hydroxyl group, based on 100 parts by weight of the base polymer having the hydroxyl group. Layered polarizing film. The polarizer is a polarizing film with an adhesive layer according to any one of claims 1 to 12, wherein the thickness is 15μm or less. The polarizer has an optical characteristic represented by the following formula:
P> − (10 ^0.929T-42.4 −1) × 100 (where T <42.3), and
P ≧ 99.9 (However, T ≧ 42.3), polarizing film pressure-sensitive adhesive layer according to any one of claims 1 to 13, characterized in that it is configured so as to satisfy the condition. Polarizing film pressure-sensitive adhesive layer according to any one of claims 1 to 14, characterized in that it has a protective film on at least one side of the polarizer. The polarizing film with an adhesive layer according to any one of claims 1 to 15 , wherein a separator is laminated on the adhesive layer. A method of manufacturing a polarizing film with an adhesive layer according to any one of claims 1-16,
Applying a water-based resin composition containing a water-based resin and methylol melamine on a polarizer, and then drying to form an anchor coat layer; and
Forming a pressure-sensitive adhesive layer on the anchor coat layer from a pressure-sensitive adhesive composition containing a base polymer having a hydroxyl group and a mercapto group-containing silane coupling agent;
The manufacturing method of the polarizing film with an adhesive layer characterized by having. An image display device having the polarizing film pressure-sensitive adhesive layer according to any one of claims 1-16.

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