TWI717392B - Polarizing film with adhesive layer, its manufacturing method and image display device - Google Patents

Abstract

The subject of the present invention is to provide a polarizing film with an adhesive layer, which sequentially has a polarizer, an anchor coating layer containing a polyvinyl alcohol-based resin, and an adhesive layer, and the adhesive layer does not contain isocyanate-based The anchoring force of the aforementioned anchor coating layer and adhesive layer is still good. The present invention is a polarizing film with an adhesive layer having a polarizer, an anchor coating layer and an adhesive layer in this order. The anchor coating layer is formed of a water-based resin composition, and the water-based resin composition contains a water-based resin composition. A resin and a compound (a) with at least one grade alcohol capable of reacting with a hydroxyl group at the molecular end. The aforementioned adhesive layer is formed of an adhesive composition containing a hydroxyl-containing base polymer and a mercapto group The silane coupling agent.

Description

Polarizing film with adhesive layer, its manufacturing method and image display device

FIELD OF THE INVENTION The present invention relates to a polarizing film with adhesive layer and its manufacturing method. The aforementioned polarizing film with an adhesive layer can be used alone or as an optical film formed by laminating them to form image display devices such as liquid crystal display devices (LCD) and organic EL display devices.

BACKGROUND OF THE INVENTION Due to the image forming method of liquid crystal display devices, it is necessary and indispensable to arrange polarizing elements on both sides of the liquid crystal element. Generally speaking, polarizing films are attached. When attaching the aforementioned polarizing film to a liquid crystal element or the like, an adhesive is usually used. In addition, in order to reduce the loss of light, the polarizing film and the liquid crystal element are usually adhered to each other with an adhesive. In this case, due to the advantages of not requiring a drying step when fixing the polarizing film, a polarizing film with an adhesive layer is generally used, which is formed by pre-installing an adhesive in the form of an adhesive layer on the side of the polarizing film By. On the adhesive layer of the polarizing film with the adhesive layer, a release film is usually attached.

For the formation of the aforementioned adhesive layer, an adhesive containing a base polymer and a crosslinking agent is usually used. The aforementioned base polymer is recommended to use an acrylic polymer, and as a crosslinking agent, it is recommended to use an isocyanate-based crosslinking agent.

In addition, from the viewpoint of thinning, a polarizing film with an adhesive layer has been proposed, which uses a single-sided protective polarizing film in which a protective film is provided on only one side of a polarizer. However, a polarizing film with a single-sided protective polarizing film with an adhesive layer is exposed to severe conditions such as thermal shock (for example, a 250-hour test at 95°C), due to the shrinkage stress of the polarizer on the side where the protective film is set The difference in the shrinkage stress of the polarizer on the opposite side of the protective film will cause excessive stress inside the polarizer, and it is easy to have micro cracks of hundreds of μm in the direction of the absorption axis of the polarizer or even through cracks that penetrate the entire surface. Various crack problems. That is, the single-sided protective polarizing film with the adhesive layer has insufficient durability under the aforementioned severe environment.

From the viewpoint of suppressing the occurrence of the aforementioned through cracks and at the same time reducing the thickness and weight, it has been proposed to provide a protective layer consisting of a water-soluble film-forming composition (polyvinyl alcohol resin composition) on at least one side of the polarizer. Layer (Patent Document 1). Prior technical literature Patent literature

Patent Document 1: Japanese Patent Publication No. 2005-043858

SUMMARY OF THE INVENTION The problem to be solved by the invention is as described above, a protective layer (anchor coating layer) formed of a polyvinyl alcohol-based resin composition is provided, and an isocyanate-based crosslinking agent-containing adhesive layer is further provided on the protective layer At this time, through the reaction between the hydroxyl group derived from the polyvinyl alcohol-based resin in the protective layer and the isocyanate group derived from the isocyanate-based crosslinking agent in the adhesive layer, the protective layer and the adhesive layer will have good anchoring power.

However, the adhesive layer containing the isocyanate-based crosslinking agent requires a certain amount of aging time after the adhesive layer is formed in order to have hardness against scratch resistance and processability, and to ensure anchoring power. In addition, since the adhesive composition containing the isocyanate-based crosslinking agent continuously undergoes self-crosslinking reaction, it has a useful life as an adhesive composition, and has a difficulty in use. On the other hand, an adhesive composition that does not contain an isocyanate-based crosslinking agent cannot sufficiently satisfy the anchoring properties of the anchor coating layer formed by the polyvinyl alcohol-based resin composition.

The object of the present invention is to provide a polarizing film with an adhesive layer, which has a polarizer, an anchor coating layer of a water-containing resin, and an adhesive layer in sequence, and the adhesive layer does not contain an isocyanate crosslinking agent, The anchoring force of the aforementioned anchor coating layer and adhesive layer is still good.

Another object of the present invention is to provide a method for manufacturing the aforementioned polarizing film with an adhesive layer. In addition, the present invention relates to an image display device having the aforementioned polarizing film with an adhesive layer. Means to solve the problem

The inventors of the present case have conducted careful research and found that the above-mentioned problems can be solved by the following polarizing film with adhesive layer, etc., and finally completed the present invention.

That is to say, the present invention relates to a polarizing film with an adhesive layer, which is characterized in that the polarizing film with an adhesive layer has a polarizer, an anchor coating layer and an adhesive layer in sequence, and the anchor coating layer is composed of A water-based resin composition is formed, the water-based resin composition contains a water-based resin and at least one compound (a) that can react with a hydroxyl group at the molecular terminal, and the adhesive layer is formed of the adhesive composition. The adhesive composition contains a hydroxyl-containing base polymer and a mercapto-containing silane coupling agent.

唑啉基之聚合物中至少1者來作為前述水系樹脂。前述水系樹脂宜為聚乙烯醇系樹脂。又，前述聚乙烯醇系樹脂宜皂化度為96莫耳%以上且平均聚合度為2000以上。The aforementioned polarizing film with adhesive layer can be selected from polyvinyl alcohol-based resins, polyurethane-based resins and containing

At least one of the oxazoline-based polymers is used as the aforementioned water-based resin. The aforementioned water-based resin is preferably a polyvinyl alcohol-based resin. Furthermore, it is preferable that the polyvinyl alcohol-based resin has a saponification degree of 96 mol% or more and an average degree of polymerization of 2,000 or more.

In the polarizing film with the adhesive layer, the water-based resin composition preferably contains 0.2 to 20 parts by weight of the compound (a) relative to 100 parts by weight of the water-based resin.

In the aforementioned polarizing film with adhesive layer, the aforementioned compound (a) can be suitably methylol melamine.

In the polarizing film with the adhesive layer, the thickness of the anchor coating layer is preferably 0.05 μm or more and 6 μm or less.

In the aforementioned polarizing film with adhesive layer, the aforementioned hydroxyl-containing base polymer can be a (meth)acrylic polymer with hydroxyl.

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

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

In the polarizing film with the adhesive layer, the adhesive composition contains 0.01 to 2 parts by weight of the crosslinking agent (b) that does not react with the hydroxyl group relative to 100 parts by weight of the hydroxyl-containing base polymer.

In the polarizing film with the adhesive layer, the thickness of the polarizing member is preferably 15 μm or less.

The aforementioned polarizing film with adhesive should be constructed so that the optical properties of the aforementioned polarizer represented by the monomer transmittance T and the degree of polarization P satisfy the conditions of the following formula: P>-(10 ^0.929T-42.4 -1)× 100 (only T<42.3), and P≧99.9 (only T≧42.3).

In the polarizing film with the adhesive layer, a protective film may be provided on at least one side of the polarizing member.

In the polarizing film with the adhesive layer, a separator may be laminated on the adhesive layer.

The present invention also relates to a method for manufacturing a polarizing film with an adhesive layer, that is, the method for manufacturing a polarizing film with an adhesive layer, characterized in that the method has the following steps: The step of forming an anchor coating layer is A water-based resin composition is coated on the polarizer and then dried to form an anchor coating layer, wherein the water-based resin composition includes a water-based resin and a compound (a) having at least one primary alcohol that can react with a hydroxyl group at the molecular end , The step of forming the adhesive layer is to form an adhesive layer on the anchor coating layer by an adhesive composition containing a hydroxyl-containing base polymer and a mercapto group-containing silane coupling agent.

In addition, the present invention relates to an image display device having the aforementioned polarizing film with an adhesive layer. Invention effect

The polarizing film with an adhesive layer of the present invention has a polarizer, an anchor coating layer of a water-containing resin, and an adhesive layer in this order. The aforementioned anchor coating layer contains at least one compound (a) capable of reacting with a hydroxyl group at the molecular end, such as methylol melamine; the aforementioned adhesive layer contains a silane coupling agent with a mercapto group. It is conceivable that the primary alcohol at the end of the methylol melamine and the like in the anchor coating layer will react with the water-based resin (such as polyvinyl alcohol resin) of the anchor coating layer, and on the other hand, it will react with the adhesive The silanol group of the sulfhydryl-containing silane coupling agent in the layer reacts. It is further conceivable that when the anchor coating layer is directly provided on the polarizer, the primary alcohol at the end of the methylol melamine and the like in the anchor coating layer will be different from the polyvinyl alcohol resin in the polarizer. The hydroxyl group reacts. It is also conceivable that the silanol group of the sulfhydryl-containing silane coupling agent will react with the hydroxyl group derived from the base polymer in the adhesive layer. It is also conceivable that the sulfhydryl-containing silane coupling agent can use the reaction of sulfhydryl groups (-SH, thiol group) in the adhesive layer to self-condense, thereby forming a sulfide bond and improving the cross-linking of the adhesive layer . It can be imagined that by reacting and bonding the materials in the aforementioned anchor coating layer and the aforementioned adhesive layer, even if the aforementioned adhesive layer does not contain an isocyanate-based crosslinking agent, the aforementioned anchor coating layer and the aforementioned adhesive The layer still has good anchoring properties.

Detailed Description of Preferred Embodiments The following describes the polarizing films 10, 11, and 12 with an adhesive layer of the present invention with reference to FIGS. 1 to 3. The polarizing films 10, 11, and 12 with the adhesive layer all contain the polarizer 1, the anchor coating layer 2 of water-based resin, and the adhesive layer 3 in sequence. As shown in FIGS. 1 and 2, the polarizing films 10 and 11 with the adhesive layer of the present invention can directly provide an anchor coating layer 2 formed of an aqueous resin composition of an aqueous resin on the polarizer 1. As shown in Figs. 2 and 3, protective films 5, 5´ can be arranged on one or both sides of the polarizer 1. FIG. 2 is an example of a situation in which the polarizing film 10 to which the adhesive layer is attached has a protective film 5 on the opposite side of the polarizer 1 to the side where the anchor coating layer 2 is provided. In addition, FIG. 3 illustrates a situation in which the polarizing film 10 with the adhesive layer has protective films 5, 5´ on both sides of the polarizing member 1, and the anchor coating layer 2 is provided on the protective film 5´ side. In addition, although not shown in FIG. 2 and FIG. 3, the polarizer 1 and the protective film 5 can be laminated via an intermediary layer such as an adhesive layer, an adhesive layer, and an undercoat (primer layer). Also, although not shown, an easy-adhesion layer or activation treatment may be provided on the protective films 5, 5´, and then the easy-adhesion layer and the adhesive layer may be laminated.

In addition, the polarizing films 10 and 11 with the adhesive layer of the present invention can be provided with a separator 4 on the adhesive layer 3 as shown in FIGS. 1 to 3. In addition, as shown in FIGS. 2 and 3, when the polarizing film 11 with the adhesive layer has a protective film 5, a surface protective film may be provided on the protective film 5.

<Polarizer> The polarizer is not particularly limited, and various types can be used. Examples of polarizers include hydrophilic polymer films such as polyvinyl alcohol-based films, partially formalized polyvinyl alcohol-based films, and ethylene-vinyl acetate copolymer-based partially saponified films that adsorb iodine or dichroic dyes. Color materials and uniaxially stretched ones, as well as polyolefin-based alignment films such as dehydrated polyvinyl alcohol or dehydrated polyvinyl chloride. Among them, a polarizer composed of a polyvinyl alcohol-based film and a dichroic substance such as iodine is suitable. The thickness of the polarizers is not particularly limited, but is generally 2-25 μm.

A polarizer made of polyvinyl alcohol-based film dyed with iodine and then uniaxially stretched can be produced in the following way, for example: by dipping the polyvinyl alcohol film in an aqueous solution of iodine for dyeing, and then stretched to the original length of 3 ~7 times. It can also be immersed in boric acid or potassium iodide, which may contain zinc sulfate, zinc chloride, and other aqueous solutions. Furthermore, if necessary, the polyvinyl alcohol-based film may be immersed in water for washing before dyeing. By washing the polyvinyl alcohol-based film with water, the dirt and anti-caking agent on the surface of the polyvinyl alcohol-based film can be washed. In addition, it also has the effect of swelling the polyvinyl alcohol-based film to prevent unevenness such as uneven dyeing. The extension can be performed after dyeing with iodine, or it can be extended while dyeing, or it can be dyed with iodine after extension. It can also be extended in aqueous solutions such as boric acid or potassium iodide or in a water bath.

A thin polarizer with a thickness of 15 μm or less can be used as the aforementioned polarizer. The thickness of the polarizer is preferably 12 μm, more preferably 10 μm or less, more preferably 8 μm or less, more preferably 7 μm or less, and more preferably 6 μm or less from the viewpoint of thinning and resistance to cracks caused by thermal shock. On the other hand, the thickness of the polarizer is preferably 2 μm or more, more preferably 3 μm or more. Such a thin polarizer has less variation in thickness, excellent visibility (visibility), and low dimensional change, so it has excellent durability against thermal shock.

Thin polarizers with a thickness of 15 μm or less can be representatively listed in Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, Japanese Patent No. 5587517, International Publication No. 2014/077599 Pamphlet, International Publication No. 2014/077636 Pamphlet, etc. Thin polarizing films (polarizers) or thin polarizing films (polarizers) produced by the manufacturing methods described in them.

The aforementioned polarizer should be constructed so that its optical characteristics expressed by monomer transmittance T and polarization degree P satisfy the conditions of the following formula: P>-(10 ^0.929T-42.4 -1)×100 (but T<42.3) and P ≧99.9 (but T≧42.3). The so-called polarizer configured to satisfy the aforementioned conditions undoubtedly has the performance required for a liquid crystal television display using a large display element. Specifically, the contrast ratio is 1000:1 or more and the maximum brightness is 500 cd/m ² or more. For other purposes, for example, it can be attached to the viewing side of an organic EL display device.

As the aforementioned thin polarizing film, in a manufacturing method including a step of stretching in a laminate state and a step of dyeing, in terms of stretching at a high magnification and improving the polarization performance, it is suitable as described in Japanese Patent No. 4751486, Japanese Patent As described in the specification No. 4751481 and the specification No. 4815544 of Japanese Patent No. 4815544, the preparation method includes the step of extending in an aqueous solution of boric acid, and it is particularly preferable that the specification contained in the specification of Japanese Patent No. 4751481 and Japanese Patent No. 4815544 is contained in boric acid. Obtained from the manufacturing method of performing auxiliary aerial stretching step before stretching in aqueous solution. These thin polarizing films can be prepared by a manufacturing method including the following steps: a step of stretching a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a resin substrate for stretching in a laminated state; and Staining step. According to this method, even if the PVA-based resin layer is very thin, it can still be stretched without being broken due to stretching by supporting it with the stretching resin substrate.

<Protective film> The material constituting the above-mentioned protective film is preferably one that is excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, and isotropy. Examples include polyester-based polymers such as polyethylene terephthalate and polyethylene naphthalate; cellulose-based polymers such as cellulose diacetate and cellulose triacetate; polymethyl methacrylate, etc. Acrylic polymers; styrene polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin); and polycarbonate polymers. In addition, the following polymers can also be cited as examples of the polymers forming the above-mentioned protective film: polyethylene, polypropylene, polyolefins having cyclic or even norbornene structures, such as polyolefin polymerization of ethylene-propylene copolymers Compounds, chlorinated vinyl polymers, amide-based polymers such as nylon and aromatic polyamides, imine-based polymers, turbid polymers, polyether turbid polymers, polyether ether ketone polymers, Polyphenylene sulfide polymer, vinyl alcohol polymer, chlorinated vinylidene polymer, vinyl butyral polymer, aryl ester polymer, polyoxymethylene polymer, epoxy polymer or the above-mentioned polymerization Blends of materials, etc. The protective films are usually attached to the polarizer via an adhesive layer. In addition, the aforementioned protective film can be made of thermosetting resins such as (meth)acrylic, urethane, acrylic urethane, epoxy, silicone, or ultraviolet curable resins. It is formed by coating and hardening the polarizer.

A retardation film can be used as the aforementioned protective film. Examples of the retardation film include those having a frontal retardation of 40 nm or more and/or a thickness direction retardation of 80 nm or more. The frontal phase difference is usually controlled in the range of 40~200nm, and the thickness direction phase difference is usually controlled in the range of 80~300nm. When a retardation film is used as a protective film, since the retardation film also functions as a polarizer protective film, thickness reduction can be achieved.

Examples of the retardation film include birefringent films obtained by uniaxially or biaxially stretching a thermoplastic resin film. The stretching temperature, stretching ratio, etc. can be appropriately set according to the retardation value, film material and thickness.

The thickness of the aforementioned protective film can be appropriately determined, but generally, from the viewpoints of workability such as strength and handling, and thin layer properties, it is preferably 3~200μm, and more preferably 3~100μm. In particular, the thickness of the aforementioned protective film (when a film is formed in advance) is preferably 10 to 60 μm, and 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 3-25 μm, and more preferably 3-20 μm from the viewpoint of transportability. The aforementioned protective film may use multiple sheets or multiple layers.

Functional layers such as hard coating, anti-reflection layer, anti-adhesion layer, diffusion layer and anti-glare layer can be provided on the surface of the aforementioned protective film that is not bonded to the polarizer. In addition, the above-mentioned functional layers such as the hard layer, anti-reflection layer, anti-adhesion layer, diffusion layer, and anti-glare layer can be provided on the protective film itself, or can be provided separately from the protective film and be another entity.

<Intermediate layer> The aforementioned protective film and polarizer are laminated via an intermediary layer such as an adhesive layer, an adhesive layer, and an undercoat layer (primer layer). At this time, it is ideal to use an interposer to laminate the two without air gaps.

The adhesive layer is formed by the adhesive. The type of adhesive is not particularly limited, and various types can be used. The aforementioned adhesive layer is not particularly limited as long as it is optically transparent, and various forms such as water-based, solvent-based, hot-melt adhesive-based, active energy ray hardening type, etc. can be used as the adhesive. However, water-based adhesives are ideal. Agent or active energy ray hardening adhesive.

Examples of water-based adhesives include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, and water-based polyesters. The water-based adhesive is usually used in the form of an adhesive composed of an aqueous solution, and usually contains 0.5 to 60% by weight of solid content.

The active energy ray hardening adhesive is an adhesive that is hardened by active energy rays such as electron beams and ultraviolet rays (radical hardening type, cation hardening type), and for example, electron ray hardening type and ultraviolet hardening type can be used. As the active energy ray curable adhesive agent, for example, a light radical curable adhesive agent can be used. When a photoradical curable active energy ray curable adhesive is used as an ultraviolet curable adhesive, the adhesive contains a radical polymerizable compound and a photopolymerization initiator.

In addition, when the aforementioned adhesive is applied using a water-based adhesive or the like, it is preferable to perform the adhesive layer finally formed with a thickness of 30 to 300 nm. The thickness of the aforementioned adhesive layer is more preferably 60 to 250 nm. On the other hand, when an active energy ray-curable adhesive is used, it is preferable to carry out so that the thickness of the adhesive layer is 0.1 to 200 μm. It is preferably 0.5 to 50 μm, more preferably 0.5 to 10 μm.

In addition, when the polarizer and the protective film are laminated, an easy-to-bond layer can be provided between the protective film and the adhesive layer.

唑啉基之聚合物中任意至少1者。其等之中，在如圖1和圖2般將錨定塗覆層直接形成於偏光件上的情形時，從抑制貫通裂紋發生的觀點來看，宜以聚乙烯醇系樹脂作為前述水系樹脂。另一方面，在如圖3般將錨定塗覆層形成於保護薄膜上的情形時，從對保護薄膜的塗膜形成性或濕潤性等觀點來看，宜以聚胺甲酸酯系樹脂、含

唑啉基之聚合物作為前述水系樹脂。<Anchor Coating Layer> The anchor coating layer contains water-based resin. The anchor coating layer can be formed by coating the water-based resin composition of the water-based resin on the polarizer. The aforementioned water-based resin can be used, for example, selected from polyvinyl alcohol-based resins, polyurethane-based resins, and containing

Any at least one of the oxazoline-based polymers. Among them, when the anchor coating layer is directly formed on the polarizer as shown in Figures 1 and 2, from the viewpoint of suppressing the occurrence of through cracks, it is preferable to use a polyvinyl alcohol-based resin as the water-based resin. . On the other hand, when the anchor coating layer is formed on the protective film as shown in Figure 3, from the viewpoints of film formation and wettability on the protective film, it is preferable to use a polyurethane resin , Containing

The oxazoline-based polymer serves as the aforementioned water-based resin.

Examples of the polyvinyl alcohol-based resin include polyvinyl alcohol. Polyvinyl alcohol is obtained by saponifying polyvinyl acetate. In addition, polyvinyl alcohol-based resins include, for example, saponified products of copolymers of vinyl acetate and copolymerizable monomers. When the aforementioned copolymerizable monomer is ethylene, an ethylene-vinyl alcohol copolymer is obtained. In addition, the aforementioned copolymerizable monomers include unsaturated carboxylic acids such as maleic acid (anhydride), fumaric acid, crotonic acid, itaconic acid, (meth)acrylic acid, and their esters, ethylene, propylene, etc. -Olefins, (meth)acrylic acid (sodium), sodium sulfonate (monoalkylmalate), sodium disulfonate alkylmalate, N-methylol acrylamide, acrylamide alkyl Sulfonic acid alkali metal salt, N-vinylpyrrolidone, N-vinylpyrrolidone derivatives, etc. These polyvinyl alcohol-based resins can be used alone or in combination of two or more. From the viewpoint of controlling the heat of fusion of crystals of the anchor layer to 30 mj/mg or more and satisfying moisture and heat resistance and water resistance, polyvinyl alcohol obtained by saponification of polyvinyl acetate is preferable.

The degree of saponification of the aforementioned polyvinyl alcohol resin can be, for example, 95 mol% or more. However, from the viewpoint of satisfying moisture and heat resistance and water resistance, the saponification degree is preferably 96 mol% or more, preferably 99 mol% % Or more, more preferably 99.5 mol% or more. The degree of saponification means the ratio of units that can actually be saponified into vinyl alcohol units among the units that can be converted into vinyl alcohol units by saponification, and the residues are vinyl ester units. The degree of saponification is determined based on JIS K 6726-1994.

The average degree of polymerization of the polyvinyl alcohol-based resin may be, for example, 500 or more. However, from the viewpoint of satisfying the moisture and heat resistance and water resistance of the anchor layer, the average degree of polymerization is preferably 1,000 or more, more preferably 1,500 or more. It is more preferably above 2000. The average degree of polymerization of the polyvinyl alcohol-based resin is measured in accordance with JIS-K6726.

In addition, as the polyvinyl alcohol-based resin, a modified polyvinyl alcohol-based resin having a hydrophilic functional group on the side chain of the polyvinyl alcohol or its copolymer can be used. Examples of the aforementioned hydrophilic functional groups include acetylacetoxy and carbonyl groups. In other respects, modified polyvinyl alcohol obtained by acetalizing, urethane-forming, etherifying, grafting, and phosphoricating a polyvinyl alcohol-based resin can be used.

As the polyurethane-based resin, an emulsion of a polyurethane-based resin can be used. In addition, the polyurethane resin emulsion can be formed by self-emulsification without using an emulsifier.

As the polyurethane-based resin, for example, a one-liquid type resin obtained by the addition polymerization reaction of a polymer polyol and an isocyanate compound can be used. As the one-component polyurethane-based resin, for example, polyether-based polyurethane resin, polyester-based polyurethane resin, etc. can be used. The aforementioned polyurethane resin is preferably one that still has residual hydroxyl groups. Specifically, for example, a lacquer-type polyurethane resin is mentioned. The aforementioned polyurethane resin can form a film only by drying and removing the solvent or water.

Polyether polyurethane resins are generally obtained by the addition polymerization reaction of polyether polyols and isocyanate compounds. The polyether polyol is a product obtained by subjecting one or more polyols to an addition reaction through ring-opening polymerization of alkylene oxide. Polyester-based polyurethane resins are generally obtained by addition polymerization of polyester polyols and isocyanate compounds. Polyester polyol is obtained by condensation polymerization of polyol and polyacid. In addition, the number average molecular weight of polymer polyols such as polyether polyol or polyether polyol is preferably 400-3000, and preferably 500-2000. Polymer polyols such as polyether polyols and polyester polyols may be used singly, or a copolymer using two or more types.

As the isocyanate compound, generally, aromatic, araliphatic, aliphatic, or alicyclic isocyanates used in polyurethane can be suitably used. In addition, as the isocyanate compound, adducts, dimers, trimers, and polymers of the aforementioned isocyanate compounds can also be used. In addition, as the isocyanate compound, a modified isocyanate obtained by urethane, uretdione, carbodiimide, etc., of a part of the above isocyanate can also be used.

When dispersing the aforementioned polyurethane resin in water, there is known a method of forcibly emulsifying and dispersing the resin using an emulsifier to prepare it. It is also possible to use an anionic group, a cationic group or a nonionic group as a water-dispersible hydrophilic group into the aforementioned resin to form a self-emulsified product. Ionic polymer complexes can also be used.

Examples of polyurethane resin emulsions include the ADEKA BONTIGHTER HUX series manufactured by Asahi Denka Kogyo Co., Ltd. that are self-emulsified without using an emulsifier. In addition, specific examples of the water-based urethane resin include SUPERFLEX series manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., Takelac W-6020 manufactured by Mitsui Chemicals Polyurethane Co., Ltd., and the like.

As the epoxy resin, an emulsion of epoxy resin can be used. When dispersing the epoxy resin in water, a method of forcibly emulsifying and dispersing the resin using an emulsifier is known. Examples of the epoxy resin include the ADEKA RESIN EM series manufactured by ADEKA Co., Ltd., and Celloxide 2021P manufactured by DAICEL (Stock).

唑啉基之聚合物可舉例如含有由丙烯醯骨架或苯乙烯骨架構成之主鏈且該主鏈的側鏈有

唑啉基的聚合物。前述之中又宜為含有由丙烯醯基骨架構成之主鏈且該主鏈之側鏈有

唑啉基的含

唑啉基之丙烯酸系聚合物。With

The oxazoline-based polymer may, for example, contain a main chain composed of an acryl skeleton or a styrene skeleton and the side chain of the main chain has

Oxazoline-based polymers. Among the foregoing, it is also preferable to contain a main chain composed of an acrylic skeleton and the side chain of the main chain has

Oxazoline containing

The oxazoline-based acrylic polymer.

唑啉基可舉例如2-

唑啉基、3-

唑啉基、4-

唑啉基等，其等之中以2-

唑啉基為宜。2-

唑啉基一般以下述一般式(1)表示。

The oxazoline group can be for example 2-

Oxazoline, 3-

Oxazoline, 4-

Oxazolinyl, etc., among them 2-

Oxazoline is preferred. 2-

The oxazoline group is generally represented by the following general formula (1).

(式中，R¹ ~R⁴ 各自獨立地表示氫原子、鹵素原子、烷基、芳烷基、苯基或經取代之苯基。)【化1】

(In the formula, R ¹ to R ⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, a phenyl group, or a substituted phenyl group.)

唑啉基之聚合物除了

唑啉基以外亦可含有聚氧伸烷基。Also, the foregoing contains

In addition to oxazoline-based polymers

In addition to the oxazoline group, a polyoxyalkylene group may be contained.

唑啉基之聚合物，其數量平均分子量以5,000以上為佳，而10,000以上較佳，並通常1,000,000以下為佳。數量平均分子量一旦低於5,000，就會有錨定層強度不足引發凝集破壞現象而使投錨力無法提升的狀況。數量平均分子量一旦高於1,000,000，就會有作業性差的狀況。又，含

唑啉基之聚合物，其

唑啉價係例如以1,500gsolid/eq.以下為佳，而1,200g solid/eq.以下較佳。

唑啉價一旦較1,500g solid/eq.更大，就會有分子中所含

唑啉基的量變少而投錨力無法提升的狀況。With

The number average molecular weight of the oxazoline-based polymer is preferably 5,000 or more, more preferably 10,000 or more, and usually less than 1,000,000. Once the number average molecular weight is less than 5,000, there will be a situation where the strength of the anchor layer is insufficient to cause agglomeration failure and the anchoring force cannot be improved. Once the number average molecular weight is higher than 1,000,000, the workability will be poor. Also, including

Oxazoline-based polymers, which

The oxazoline valence is preferably 1,500 g solid/eq. or less, and 1,200 g solid/eq. or less.

Once the oxazoline value is greater than 1,500g solid/eq., there will be contained in the molecule

A situation where the amount of oxazoline groups decreases and the anchoring force cannot be improved.

唑啉基之聚合物，其

唑啉基與黏著劑組成物所含羥基是在相對低溫之下進行反應，故若令錨定塗覆層中含有含

唑啉基之聚合物，就可與黏著劑層中的官能基等發生反應而強固地密著。With

Oxazoline-based polymers, which

The oxazoline group reacts with the hydroxyl group contained in the adhesive composition at a relatively low temperature, so if the anchor coating layer contains

The oxazoline-based polymer can react with the functional groups in the adhesive layer to adhere firmly.

唑啉基之聚合物具體上可舉如(股)日本觸媒製EPOCROS WS-300、EPOCROS WS-500、EPOCROS WS-700等含

唑啉基之丙烯酸系聚合物，並可舉例如(股)日本觸媒製EPOCROS K-1000系列、EPOCROS K-2000系列等含

唑啉基之丙烯酸系/苯乙烯系聚合物等等，且可單獨使用1種或合併使用2種以上。With

Specific examples of oxazoline-based polymers include EPOCROS WS-300, EPOCROS WS-500, EPOCROS WS-700, etc. manufactured by Nippon Shokubai Co., Ltd.

Acrylic polymers based on oxazoline groups, such as EPOCROS K-1000 series and EPOCROS K-2000 series manufactured by Nippon Shokubai Co., Ltd.

The oxazoline-based acrylic/styrene polymer, etc., can be used singly or in combination of two or more.

The anchor coating layer of the present invention is formed of a water-based resin composition containing the aforementioned water-based resin as the main component, and the aforementioned water-based resin composition further contains compound (a), which has at least one hydroxyl group at the molecular end The primary alcohol of the reaction. By introducing the aforementioned compound (a) into the anchor coating layer, it can be promoted as described above and between the mercapto group-containing silane coupling agent and the hydroxyl-containing base polymer in the adhesive composition that can form the adhesive layer The reaction, and enhance the anchoring force of the anchor coating layer and the adhesive layer.

The aforementioned water-based resin preferably does not have a functional group that is reactive to "the first-order alcohol that the aforementioned compound (a) has which can react with the hydroxyl group". Among the water-based resins exemplified above, polyvinyl alcohol-based resins are also preferred, and particularly preferred is Use unmodified polyvinyl alcohol resin. Or, in the case of using unmodified polyvinyl alcohol resin, the aforementioned hydrophilic functional group related to the modification is related to the primary alcohol of the aforementioned compound (a) that can react with the hydroxyl group, The reactivity of the hydrophilic functional group is preferably lower than the functional group (silanol group) of the sulfhydryl-containing silane coupling agent in the adhesive composition.

The aforementioned compound (a) is preferably blended in 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 water-based resin. Setting the ratio of the aforementioned compound (a) to 0.2 parts by weight or more is suitable for increasing the aforementioned anchoring force. The ratio of the aforementioned compound (a) is preferably 1 part by weight or more, more preferably 3 parts by weight or more. On the other hand, if the ratio of the aforementioned compound (a) increases, the water resistance or appearance (appearance for confirming uneven defects in the polarizing film) will deteriorate, so the ratio of the aforementioned compound (a) is preferably 20 parts by weight Hereinafter, it is more preferably 10 parts by weight or less, and more preferably 7 parts by weight or less. The ratio of the aforementioned compound (a) depends on the type of the hydroxyl-containing base polymer and the mercapto-containing silane coupling agent used in the adhesive composition.

The ratio of the water-based resin in the anchor coating layer or the water-based resin composition (solid content) is preferably 80% by weight or more, more preferably 90% by weight or more, and more preferably 95% by weight or more.

The aforementioned compound (a) can ideally be a compound having at least one primary alcohol at the end of the molecule. The compound can include, for example, amino-formaldehyde resins such as methylolurea, methylolmelamine, alkylated methylolurea and formaldehyde condensation products, ethylene glycol, glycerol, 1,6-hexanediol, 1,8-octanediol, aliphatic alcohol, polyethylene glycol. Among them, amine-formaldehyde resin is preferred, and among them, methylol melamine is preferred.

It is also possible to use compounds having a functional group capable of reacting with a hydroxyl group other than the aforementioned compound (a). For example, a compound having an amine group at the end of the molecule can be mentioned. The compound may include, for example, alkylene diamines having alkylene groups and two amine groups such as ethylene diamine, triethylene diamine, and hexamethylene diamine; hydrazine; dihydrazine adipate, dihydrazine oxalate, propylene Dihydrazine diacid, dihydrazine succinate, dihydrazine glutarate, dihydrazine isophthalate, dihydrazine sebacate, dihydrazide maleate, dihydrazide fumarate, dihydrazide iticonate Dicarboxylic acid dihydrazine such as hydrazine; water-soluble dihydrazine such as ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine, butene-1,4-dihydrazine, etc. Among them, hydrazine is suitable. A compound having an amine group at the molecular end, for example, when the base polymer of the adhesive composition has a hydroxyl group (that is, when the base polymer is a (meth)acrylic polymer, it contains a hydroxyl-containing monomer as a monomer unit) appropriate.

Furthermore, the compound having a functional group capable of reacting with a hydroxyl group other than the aforementioned compound (a) includes, for example, toluene diisocyanate, hydrogenated toluene diisocyanate, trimethylolpropane toluene diisocyanate adduct, and triphenylmethane triisocyanate , Methylene bis(4-phenylmethane triisocyanate, isophorone diisocyanate and other isocyanates such as ketoxime block or phenol block; ethylene glycol diglycidyl ether, polyethylene glycol Diglycidyl ether, glycerin di or triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl ether Epoxides such as aniline and diglycidylamine; monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde; glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, malealdehyde , Phthalaldehyde and other dialdehydes; alkylated methylolated melamine, acetguanamine, benzoguanamine and formaldehyde condensate and other amino-formaldehyde resins; and sodium, potassium, magnesium, calcium, aluminum Salts and oxides of divalent or trivalent metals such as iron, nickel, etc. Among them, amino-formaldehyde resin and water-soluble dihydrazine are preferred.

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

The water-based resin composition system is prepared as a solution in which the water-based resin is dissolved in a solvent. Examples of the solvent include water, dimethyl sulfide, dimethylformamide, and dimethylacetamide-N-methylpyrrolidone. These can be used alone or in combination of two or more kinds. Among them, it is preferable to use an aqueous solution using water as a solvent. In the aforementioned aqueous resin composition (for example, an aqueous solution), although the concentration of the aforementioned aqueous resin is not particularly limited, it is 0.1 to 15% by weight, preferably 0.5 to 10% by weight, in consideration of coating properties and storage stability. .

In addition, substances other than the aforementioned compound (a) may be added to the aforementioned aqueous resin composition (for example, an aqueous solution). For example, surfactants etc. are mentioned. Examples of the surface active agent include nonionic surface active agents. Furthermore, various stabilizers such as adhesion imparting agents, ultraviolet absorbers, antioxidants, heat-resistant stabilizers, hydrolysis-resistant stabilizers, etc. can also be blended.

The thickness of the anchor coating layer is preferably 0.05 μm, more preferably 0.2 μm or more, and the thickness of the aforementioned anchor coating layer is preferably 0.5 μm or more, more preferably 0.7 μm or more. Especially when a polyvinyl alcohol-based resin is used as the water-based resin, the thickness of the anchor coating layer is preferably 0.2 μm or more, and the anchor coating layer of this thickness can suppress the occurrence of cracks caused by thermal shock. On the other hand, once the anchor coating layer becomes too thick, the optical reliability and water resistance will decrease. Therefore, the thickness of the anchor coating layer is preferably 6 μm or less, more preferably 5 μm or less, and more preferably 3 μm or less. It is more preferably 2 μm or less.

The anchor coating layer can be formed by coating the water-based resin composition on the other side of the polarizer (the side without the protective film) and drying it. The coating of the aforementioned water-based resin composition is performed by setting the thickness after drying to the aforementioned thickness (preferably 0.2 μm or more and 6 μm or less). The coating operation is not particularly limited, and any appropriate method can be adopted. For example, roll coating method, spin coating method, wire bar coating method, dip coating method, die coating method, curtain coating method, spray coating method, blade coating method (comma blade coating method, etc.) can be used. ) And other means.

<Adhesive layer> The adhesive layer is formed of an adhesive composition, which contains a base polymer having a hydroxyl group and a silane coupling agent containing a mercapto group. For the formation of the adhesive layer, an appropriate adhesive containing a hydroxyl group can be used, and there is no particular restriction on the type thereof. Examples of adhesives include rubber adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, polyethylene Pyrolidone-based adhesives, polyacrylamide-based adhesives, cellulose-based adhesives, etc. Various base polymers can be used to wait for adhesives.

In addition, the ratio of the hydroxyl-containing base polymer in the adhesive layer or the adhesive composition (solid content) is preferably 80% by weight or more, more preferably 90% by weight or more, and more preferably 95% by weight or more.

Among these adhesives, it is also suitable to use those with good optical transparency, showing proper wettability, cohesiveness and adhesive properties, and excellent weather resistance and heat resistance. For those showing such characteristics, it is better to use an acrylic adhesive. A (meth)acrylic polymer can be used as the base polymer of the acrylic adhesive. The (meth)acrylic polymer (A) usually contains an alkyl (meth)acrylate as a main component as a monomer unit. In addition, (meth)acrylate means acrylate and/or methacrylate, and "(meth)" in the present invention has the same meaning.

As the (meth)acrylic acid alkyl ester constituting the main skeleton of the (meth)acrylic polymer, a linear or branched alkyl group having 1 to 18 carbon atoms can be exemplified. For example, examples of the aforementioned alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, cyclohexyl, heptyl, 2-ethylhexyl, and isooctyl. , Nonyl, decyl, isodecyl, dodecyl, isotetradecyl, lauryl, thirteen, pentadecyl, hexadecyl, heptadecyl, octadecyl, etc. 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 hydroxyl-containing monomers in the form of monomer units. The hydroxyl group-containing single system 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. As specific examples of hydroxyl-containing monomers, for example, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, (meth) Base)-6-hydroxyhexyl acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate,-12-hydroxylauryl (meth)acrylate, etc. (meth) Hydroxyalkyl acrylate, or (4-hydroxymethylcyclohexyl) methyl acrylate, etc.

The (meth)acrylic polymer has alkyl (meth)acrylate as the main component in the weight ratio of the total constituent monomers, and the ratio of the aforementioned hydroxyl-containing monomer in the (meth)acrylic polymer is in the total constituent The weight ratio of the monomers is preferably 0.01-15%, more preferably 0.03-10%, more preferably 0.05-7%.

Furthermore, in the aforementioned (meth)acrylic polymer, for the purpose of improving adhesiveness, heat resistance, etc., one or more copolymerizable monomers having a polymerizable functional group can be introduced by copolymerization. The polymerizable functional group It has unsaturated double bonds such as (meth)acryloyl or vinyl groups.

The aforementioned comonomers include, for example, (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and other carboxyl-containing monomers ; Maleic anhydride, itaconic anhydride and other acid anhydride group-containing monomers; acrylic acid caprolactone adducts; styrene sulfonic acid or allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropane Sulfonic acid, (meth)acrylic acid propanesulfonic acid, (meth)acrylic acid sulfopropyl ester, (meth)acrylic acid oxynaphthalene sulfonic acid and other sulfonic acid group-containing monomers; 2-hydroxyethyl acrylic acid group Phosphate/ester and other phosphoric acid group-containing monomers, etc.

In addition, examples of monomers for modification purposes may also include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide or N -Methylol (meth)acrylamide, N-methylolpropane (meth)acrylamide and other (N-substituted) amide monomers; (meth)aminoethyl acrylate, (meth) Acrylic acid-N,N-dimethylaminoethyl, (meth)acrylic acid tertiary butylaminoethyl and other (meth)acrylic acid alkylamine alkyl ester monomers; (meth)acrylic acid methoxyethyl , (Meth) ethoxy ethyl acrylate and other (meth) acrylic acid alkoxyalkyl ester monomers; N-(meth)acryloyloxymethylene succinimide or N-(methyl) Amber such as acryl-6-oxyhexamethylene succinimidyl, N-(meth) acryl-8-oxyoctamethylene succinimine, N-acrylonitrile mopholin, etc. Amide monomers; N-cyclohexylmaleimide or N-isopropylmaleimide, N-laurylmaleimide or N-phenylmaleimide, etc. Iconimines; N-methyl Iconimines, N-ethyl Iconimines, N-butyl Iconimines, N-octyl Iconimines, N-2 -Ethylhexyl Ikonimines, N-cyclohexyl Ikonimines, N-Lauryl Ikonimines and other Ikonimines, etc.

唑、乙烯嗎福林、N-乙烯羧酸醯胺類、苯乙烯、α-甲基苯乙烯、N-乙烯己內醯胺等乙烯系單體；丙烯腈、甲基丙烯腈等氰基丙烯酸酯系單體；(甲基)丙烯酸環氧丙酯等含環氧基之丙烯酸系單體；聚乙二醇(甲基)丙烯酸酯、聚丙二醇(甲基)丙烯酸酯、甲氧基乙二醇(甲基)丙烯酸酯、甲氧基聚丙二醇(甲基)丙烯酸酯等二醇系丙烯酸酯單體；(甲基)丙烯酸四氫呋喃甲酯、氟素(甲基)丙烯酸酯、聚矽氧(甲基)丙烯酸酯或2-甲氧基乙基丙烯酸酯等丙烯酸酯系單體等等。還可舉如異戊二烯、丁二烯、異丁烯、乙烯基醚等。Furthermore, vinyl acetate, vinyl propionate, N-vinyl pyrrolidone, methyl vinyl pyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperazine, and vinyl pyrazine can also be used as modified monomers. , Vinylpyrrole, vinylimidazole, ethylene

Vinyl monomers such as azole, vinylmorphine, N-vinyl carboxamides, styrene, α-methylstyrene, N-vinyl caprolactam, etc.; cyanoacrylic acid Ester monomers; glycidyl (meth)acrylate and other epoxy-containing acrylic monomers; polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene Alcohol (meth)acrylate, methoxy polypropylene glycol (meth)acrylate and other glycol-based acrylate monomers; (meth) tetrahydrofuran methyl acrylate, fluorine (meth) acrylate, polysiloxane ( Acrylic monomers such as meth)acrylate or 2-methoxyethyl acrylate. Other examples include isoprene, butadiene, isobutylene, vinyl ether and the like.

Furthermore, copolymerizable monomers other than the above include, for example, silane-based monomers containing silicon atoms. Silane-based monomers include, for example, 3-propenyloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-ethylene Butyl triethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloxydecyltrimethoxysilane, 10-propylene Oxyoxydecyl trimethoxysilane, 10-methacryloxydecyl triethoxysilane, 10-acryloxydecyl triethoxysilane, etc.

In addition, as a comonomer, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and bisphenol A diacrylate can also be used. Glycidyl ether di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, neopenteritol tri(meth)acrylate, Neopentyl erythritol tetra (meth) acrylate, dineopentaerythritol penta (meth) acrylate, dineopentaerythritol hexa (meth) acrylate, caprolactone modified dineopentaerythritol hexa ( Polyfunctional monomers such as esters of (meth)acrylic acid and polyols, such as meth)acrylates, which have two or more (meth)acrylic groups, vinyl groups and other unsaturated double bonds, or are used in polyester, Polyester (meth)acrylic acid formed by adding two or more (meth)acrylic groups, vinyl groups, and other unsaturated double bonds with the same functional groups as the monomer components to the backbone of epoxy and urethane Ester, epoxy (meth)acrylate, urethane (meth)acrylate, etc.

The ratio of the aforementioned comonomers (other than hydroxyl-containing monomers) in the (meth)acrylic polymer is not particularly limited, but the weight ratio of the total constituent monomers is preferably about 0-20%, and about 0.1-15%. More preferably, it is about 0.1-10%.

Among these comonomers (other than hydroxyl group-containing monomers), it is preferable to use a carboxyl group-containing monomer from the viewpoint of adhesiveness and durability. In the case of containing a carboxyl group-containing monomer as a comonomer, the ratio is preferably 0.05-10% by weight, preferably 0.1-8% by weight, and particularly preferably 0.2-6% by weight.

The (meth)acrylic polymer of the present invention usually uses a weight average molecular weight in the range of 500,000 to 3 million. Considering durability, especially heat resistance, it is advisable to use a weight average molecular weight of 700,000 to 2.7 million. Furthermore, it should be 800,000 to 2.5 million. Once the weight average molecular weight is less than 500,000, it is not suitable in terms of heat resistance. Moreover, once the weight average molecular weight becomes greater than 3 million, a large amount of diluting solvent is required to adjust the viscosity to the coating, which will increase the cost, which is not suitable. In addition, the weight average molecular weight means a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

For the production of such a (meth)acrylic polymer, known production methods such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations can be appropriately selected. In addition, the obtained (meth)acrylic polymer may be any of random copolymers, block copolymers, and graft copolymers.

The polymerization initiator, chain transfer agent, emulsifier, etc. that can be used for radical polymerization are not particularly limited, and can be appropriately selected and used. In addition, the weight average molecular weight of the (meth)acrylic polymer can be controlled by the usage amount of the polymerization initiator and the chain transfer agent and the reaction conditions, and the usage amount can be appropriately adjusted according to the types of the polymerization initiator and the chain transfer agent.

Furthermore, the adhesive composition of the present invention contains a mercapto group-containing silane coupling agent in addition to the aforementioned hydroxyl-containing base polymer (such as (meth)acrylic polymer). The aforementioned mercapto group-containing silane coupling agent may include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyl Diethoxysilane, β-mercaptomethylphenylethyltrimethoxysilane, mercaptomethyltrimethoxysilane, 6-mercaptohexyltrimethoxysilane, 10-mercaptodecyltrimethoxysilane, etc. have a mercapto group The compound and so on.

In addition, 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. Specifically, for example, X-41-1805, X-41-1818, X-41-1810 manufactured by Shin-Etsu Chemical Co., Ltd. can be mentioned. These mercapto group-containing silane coupling agents are difficult to volatilize and have multiple alkoxysilyl groups, so they are suitable for effective use in improving durability. Here, the oligomer type refers to a polymer having a monomer content of 2 or more and less than 100 polymers, and the weight average molecular weight of the oligomer type silane coupling agent is preferably about 300 to 30,000.

The number of alkoxysilyl groups in the aforementioned oligomer-type mercapto-containing silane coupling agent is only 2 or more in the molecule, and the number is not limited. The number of alkoxy groups of the aforementioned oligomer-type mercapto-containing silane coupling agent is preferably 10-60% by weight, preferably 20-50% by weight, and more preferably 20-40% by weight in the silane coupling agent.

The type of alkoxy group is not limited, and examples include alkoxy groups having 1 to 6 carbon atoms such as methoxy, ethoxy, propoxy, butoxy, pentoxy, and hexyloxy. Among them, methoxy and ethoxy are preferred, and methoxy is preferred. In addition, it is preferable that both methoxy and ethoxy groups are contained in one molecule.

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

The aforementioned mercapto group-containing silane coupling agent can be used alone or in combination of two or more. The total content is 0.001 to 100 parts by weight of the aforementioned hydroxyl-containing base polymer (for example, (meth)acrylic polymer). 5 parts by weight is preferable, 0.01 to 3 parts by weight is preferable, 0.02 to 2 parts by weight is more preferable, and 0.05 to 1 part by weight is particularly preferable.

Furthermore, in the adhesive composition of the present invention, a silane coupling agent other than the aforementioned mercapto group-containing silane coupling agent may be added. Other coupling agents include 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl- N-(1,3-Dimethylbutylene)propylamine, N-phenyl-γ-aminopropyltrimethoxysilane and other amino-containing silane coupling agents; 3-propionyl allyloxypropyl trimethoxy Silane coupling agents containing (meth)acrylic acid groups such as silane, 3-methylpropionyloxypropyltriethoxysilane, etc.; isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane and many more.

Silane coupling agents other than the aforementioned 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, but for example, from the viewpoint of adhesion to adherends, It can be used in the range of 3 parts by weight or less with respect to 100 parts by weight of the adhesive composition, further can be used in the range of 2 parts by weight or less, and further can be used in the range of 1 part by weight or less. Adhesiveness can be improved by using silane coupling agents other than mercapto groups. However, silane coupling agents other than mercapto groups may also impart reworkability, so if the added amount is higher, the adhesion tends to deteriorate.

Furthermore, the adhesive composition of the present invention may contain a crosslinking agent. The aforementioned crosslinking agent may be used alone or in combination of two or more kinds. The content of the entire crosslinking agent is preferably 2 parts by weight or less, more preferably 1.5 parts by weight or less, and more preferably 1 part by weight or less relative to 100 parts by weight of the aforementioned hydroxyl-containing base polymer.

In the adhesive composition of the present invention, as the aforementioned crosslinking agent, it is preferable to contain a crosslinking agent (b) that does not react with the hydroxyl group. The aforementioned crosslinking agent (b) which does not react with the hydroxyl group can also be used in combination with an isocyanate-based crosslinking agent, but a form that does not contain an isocyanate-based crosslinking agent is suitable. When the adhesive composition of the present invention does not contain an isocyanate-based crosslinking agent, there is no problem on the handling surface of the service life. The cross-linking agent (b) that does not react with the hydroxyl group does not need to age until the predetermined gel fraction is reached after the adhesive layer is formed. It can be made with a gel fraction of 80 from the initial stage when the adhesive layer is formed. % Hardened material. Furthermore, it is conceivable that the cross-linking reaction caused by the cross-linking agent (b) that does not react with the hydroxyl group in the adhesive layer continues, so the hydroxyl group of the base polymer can efficiently couple with the mercapto-containing silane. The silanol groups of the mixture react, and the gel fraction of the adhesive layer can be hardened to more than 80% from the initial stage.

The aforementioned cross-linking agent (b) can be used alone or in combination of two or more, but its total content is relative to 100 parts by weight of the aforementioned hydroxyl-containing base polymer, and the aforementioned cross-linking agent (b) is 0.01-2 parts by weight More preferably, it is more preferably 0.04 to 1.5 parts by weight, more preferably 0.05 to 1 part by weight, more preferably 0.4 to 0.6 part by weight. It can be appropriately selected within this range to adjust processability, reworkability, crosslinking stability, peelability, etc.

As the aforementioned crosslinking agent (b), peroxide can be suitably used.

In addition, as a method for measuring the amount of peroxide decomposition remaining after the reaction treatment, it can be measured by, for example, HPLC (High Speed Liquid Chromatography).

More specifically, for example, about 0.2 g of the adhesive after the reaction treatment is taken out one by one, immersed in 10 ml of ethyl acetate, and extracted with a shaker at 25° C. and shaken at 120 rpm for 3 hours, and then left to stand at room temperature for 3 hours. day. Next, add 10 ml of acetonitrile, shake at 120 rpm for 30 minutes at 25°C, and then pour about 10 μl of the extract filtered through a membrane filter (0.45 μm) into HPLC for analysis, which can be used as the amount of peroxide after the reaction treatment .

As a peroxide, it can be suitably used as long as it generates free radical active species upon heating or light irradiation to crosslink the base polymer of the adhesive composition. However, considering workability and stability, it can be used for 1 minute A peroxide with a half-life temperature of 80°C to 160°C is preferred, and a peroxide with a half-life temperature of 90°C to 140°C is better.

Examples of peroxides that can be used include: bis(2-ethylhexyl)peroxydicarbonate (1 minute half-life temperature: 90.6°C), bis(4-tertiarybutylcyclohexyl)peroxydicarbonate ( 1-minute half-life temperature: 92.1°C), di-second butyl peroxydicarbonate (1-minute half-life temperature: 92.4°C), tert-butyl peroxyneodecanoate (1-minute half-life temperature: 103.5°C), peroxydicarbonate Tertiary hexyl butyrate (1 minute half-life temperature: 109.1°C), tertiary peroxyisobutyrate (1 minute half-life temperature: 110.3°C), dilaurin peroxide (1 minute half-life temperature: 116.4°C) ), di-n-octyl peroxide (1 minute half-life temperature: 117.4℃), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (1 minute half-life temperature: 124.3℃) , Di(4-Methylbenzyl) peroxide (1 minute half-life temperature: 128.2℃), Dibenzyl peroxide (1 minute half-life temperature: 130.0℃), tertiary butylperoxy isobutyric acid Ester (1 minute half-life temperature: 136.1°C), 1,1-bis(third hexylperoxy)cyclohexane (1 minute half-life temperature: 149.2°C), etc. Among them, from the viewpoint of excellent crosslinking reaction efficiency, bis(4-tertiarybutylcyclohexyl)peroxydicarbonate (1 minute half-life temperature: 92.1°C), dilaurin peroxide (1 minute Half-life temperature: 116.4°C), dibenzyl peroxide (1 minute half-life temperature: 130.0°C), etc. are suitable for use.

In addition, the half-life of peroxide is an index indicating the decomposition rate of peroxide, and means the time until the residual amount of peroxide becomes half. The decomposition temperature used to reach the half-life at any time or the half-life time at any temperature is disclosed in the manufacturer’s catalog, for example, in the "Organic Peroxide Catalog 9th Edition (2003) May)" etc.

As a crosslinking agent other than the aforementioned crosslinking agent (b), an organic crosslinking agent or a polyfunctional metal chelate can be used. Examples of the organic crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, and imine crosslinking agents. Multifunctional metal chelate is a product in which a multivalent metal and an organic compound are covalently bonded or coordinated. 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. Examples of the covalently bonded or coordinated atoms in organic compounds include oxygen atoms, and the organic compounds include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds.

The amount of the cross-linking agent used other than the aforementioned cross-linking agent (b) should be controlled so that it can produce a cured product with a gel fraction of 80% or more from the initial stage when the adhesive layer is formed. For example, with respect to 100 parts by weight of the adhesive composition, a crosslinking agent other than the aforementioned crosslinking agent (b) may be used in a range of 2 parts by weight or less, and may further be contained in a range of 1 part by weight or less, and further may be contained in a range of 0.5 parts by weight or less . In particular, when an isocyanate-based crosslinking agent is used as a crosslinking agent other than the crosslinking agent (b), the amount of use should be controlled in a range that does not require aging. The isocyanate-based crosslinking agent is suitable from the point of ensuring the anchoring force to the adherends such as films, and the point that the hardening of the adhesive layer can suppress the dimensional change of the polarizing film is also suitable. Furthermore, it is particularly suitable to use an isocyanate-based crosslinking agent in combination with a crosslinking agent (b) that does not react with a hydroxyl group to obtain a stronger anchoring force.

Furthermore, the adhesive composition of the present invention may contain alkali metal salts, polyether-modified polysiloxane compounds, and other well-known additives, for example, polyether compounds such as polypropylene glycol and other polyolefin glycols may be appropriately added depending on the application. , Colorants, pigments, powders, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, ultraviolet absorbers, Polymerization inhibitors, inorganic or organic fillers, metal powders, particles, foils, etc. In addition, within a controllable range, a redox system with a reducing agent can also be used.

Although the adhesive composition is used to form the adhesive layer, when forming the adhesive layer, it is advisable to adjust the total amount of crosslinking agent added, and fully consider the effects of crosslinking treatment temperature and crosslinking treatment time.

The crosslinking agent used can adjust the crosslinking treatment temperature and the crosslinking treatment time. The cross-linking treatment temperature is preferably below 170°C.

In addition, the cross-linking treatment can be performed at the temperature in the drying step of the adhesive layer, or it can be performed with a cross-linking treatment step after the drying step.

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

The method of forming the adhesive layer can be produced by, for example, the following method: coating the aforementioned adhesive composition on a peeling-treated separator, etc., drying and removing the polymerization solvent, etc., to form the adhesive layer, and then as shown in Figure 1 The method of transferring the state of and 2 to the anchor coating layer; is to coat the aforementioned adhesive composition on the anchor coating layer as in the state of Figures 1 and 2, and then dry and remove the polymerization solvent, etc., on the polarizing film The method of forming the adhesive layer, etc. In addition, when applying the adhesive, one or more solvents other than the polymerization solvent may be appropriately added.

Separate parts after peeling treatment should use silicone release liner material. In the step of coating the adhesive composition of the present invention on such a lining material and drying it to form an adhesive layer, an appropriate method can be adopted as a method of drying the adhesive composition depending on the purpose. It is desirable to adopt a method of heating and drying the above-mentioned coated film. The heating and 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 to the above range, an adhesive layer having excellent adhesive properties can be obtained.

Suitable drying time can be adopted. 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 can be used for forming the adhesive layer. Specifically, for example, roller coating method, contact sizing roller coating method, gravure coating method, reverse coating method, roller brush method, spraying method, dip roller coating method, bar coating method, knife coating method, gas Knife coating method, curtain coating method, lip die coating method, extrusion coating method using mold coater, etc.

The thickness of the adhesive layer is not particularly limited, for example, about 1-100 μm. It is preferably 2 to 50 μm, preferably 2 to 40 μm, and more preferably 5 to 35 μm.

When the aforementioned adhesive layer is exposed, it can also be protected by a stripped sheet (separator) before actual use.

The constituent materials of the separator include, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and non-woven fabrics, meshes, foam sheets, and metal foils. Appropriate sheets such as laminates, etc., but from the viewpoint of excellent surface smoothness, plastic films are preferably used.

The plastic film may be a film that can protect the aforementioned adhesive layer, and is not particularly limited. Examples include polyethylene film, polypropylene film, polybutene film, polypentadiene film, polymethylpentene film, Polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene-ethyl acetate copolymer film, etc.

The thickness of the aforementioned separator is generally 5 to 200 μm, and preferably about 5 to 100 μm. If necessary, the aforementioned separating parts can also be subjected to release and antifouling treatments, coating types and kneading types using silicone, fluorine, long-chain alkyl or fatty acid amide-based release agents, silica powder, etc. , Evaporation type and other antistatic treatment. In particular, by appropriately applying peeling treatments such as silicone treatment, long-chain alkyl treatment, and fluorine treatment to the surface of the separator, the peelability from the adhesive layer can be further improved.

In addition, the peeled-off sheet used in the production of the polarizing film with the adhesive layer can be directly used as a separator for the polarizing film with the adhesive layer, and the manufacturing process can be simplified.

<Surface protection film> A surface protection film can be installed on the polarizing film with the adhesive layer. The surface protection film usually has a substrate film and an adhesive layer, and the polarizer is protected through the adhesive layer.

For the base film of the surface protection film, from the viewpoints of inspection and management, a film material with isotropic or nearly isotropic properties is selected. The film material may include, for example, polyester resins such as polyethylene terephthalate film, cellulose resins, acetate resins, polyether turpentine resins, polycarbonate resins, polyamide resins, Transparent polymers such as polyimide resins, polyolefin resins, and acrylic resins. Among them, polyester resins are suitable. The base film can also be a laminate of one or more than two types of film materials, and in addition, an extension of the aforementioned film can also be used. The thickness of the substrate film is usually 500 μm or less, preferably 10 to 200 μm.

It is possible to appropriately select and use (meth)acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, fluorine-based and rubber-based polymers as a base for polymerization It is used as an adhesive to form the adhesive layer of the surface protection film. From the viewpoints of transparency, weather resistance, heat resistance, etc., it is preferably an acrylic adhesive having an acrylic polymer as a base polymer. The thickness of the adhesive layer (dry film thickness) is determined according to the required adhesive force. It is usually about 1-100μm, and preferably 5-50μm.

In addition, in the surface protection film, a release treatment layer can be provided on the side opposite to the side where the adhesive layer of the base film is provided with a low adhesion material such as silicone treatment, long-chain alkyl treatment, fluorine treatment, etc.

<Other optical layers> The polarizing film of the present invention can be used as an optical film laminated with other optical layers in actual use. The optical layer is not particularly limited. One layer or two or more layers such as reflectors and semi-transmissive plates, retardation plates (including 1/2 and 1/4 wavelength plates), viewing angle compensation films, etc. can be used. For forming optical layers of liquid crystal display devices. Particularly preferred is a reflective polarizing film or a semi-transmissive polarizing film formed by laminating a reflective plate or a semi-transmissive polarizing film on the polarizing film with an adhesive layer of the present invention, and then laminating a retardation plate on the polarizing film The elliptical polarizing film or circular polarizing film, the wide viewing angle polarizing film formed by laminating the viewing angle compensation film on the polarizing film, or the polarizing film formed by laminating the brightness enhancement film on the polarizing film.

The optical film formed by laminating the above-mentioned optical layer on the polarizing film with the adhesive layer can also be formed in a sequential manner during the manufacturing process of liquid crystal display devices. However, the quality of the optical film is stable when the optical film is laminated in advance. It has advantages in terms of performance and assembly operations, and has the advantage of improving the manufacturing process of liquid crystal display devices. It can be laminated with an appropriate bonding method such as an adhesive layer. When the polarizing film with the adhesive layer and other optical layers are attached, the optical axis of the polarizing film and other optical layers can be arranged at an appropriate angle in accordance with the intended retardation characteristics.

The polarizing film or optical film with the adhesive layer of the present invention can be suitably used for the formation of various devices such as liquid crystal display devices. The formation of the liquid crystal display device can be implemented according to known techniques. That is, a liquid crystal display device is generally formed by appropriately assembling structural parts such as a liquid crystal element, a polarizing film or optical film with an adhesive layer, and an illumination system as needed, and installing a driving circuit. In the present invention, except for The polarizing film or optical film with the adhesive layer of the present invention is not particularly limited except for this point, and can be based on conventional knowledge. As for the liquid crystal element, any type such as IPS type and VA type can be used.

It can be formed in a liquid crystal display device with a polarizing film or optical film with an adhesive layer arranged on one side or both sides of a liquid crystal element, or an appropriate liquid crystal display device that uses a backlight or a reflector for the lighting system. In this case, the polarizing film or optical film with the adhesive layer of the present invention can be arranged on one side or both sides of the liquid crystal element. When polarizing films or optical films with adhesive layers are arranged on both sides, they may be the same or different. In addition, when forming a liquid crystal display device, for example, a diffuser, an anti-glare layer, an anti-reflection film, a protective plate, a ray array, a lens array sheet, a light diffuser, a backlight, and other appropriate parts can be arranged in a suitable position. Or more than 2 layers. Example

Hereinafter, examples are given to illustrate the present invention, but the present invention is not limited to the examples shown below. In addition, parts and% in each example are based on weight. The following unspecified room temperature storage conditions are 23°C 65%RH.

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

<Production of polarizer> Amorphous isophthalic acid-copolymer-polyethylene terephthalate (IPA-copolymer-PET) film (thickness: 100μm) substrate with a water absorption rate of 0.75% and Tg75°C The corona treatment is applied to the surface, and the corona treatment surface is coated at 25°C with a ratio of 9:1 containing polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetyl acetonitrile modified Aqueous solution of high-quality PVA (polymerization degree 1200, acetyl acetyl modification degree 4.6%, saponification degree 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gohsefimer Z200") and dried to form a PVA with a thickness of 11 μm The resin layer is formed to produce a laminate. The obtained laminate was subjected to uniaxial stretching of the free end (in-air auxiliary stretching treatment) at 2.0 times the longitudinal direction (longitudinal direction) between rollers having different peripheral speeds in an oven at 120°C. Next, the layered body was immersed in an insolubilization bath (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 30°C for 30 seconds (insolubilization treatment). Next, while immersing in a dyeing bath at a liquid temperature of 30°C, the iodine concentration and immersion time were adjusted so that the polarizing plate had a predetermined transmittance. In this example, it was immersed in an iodine aqueous solution obtained by mixing 0.2 parts by weight of iodine and 1.0 part by weight of potassium iodide with respect to 100 parts by weight of water for 60 seconds (dyeing treatment). Next, it was immersed in a crosslinking bath (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 30°C for 30 seconds (crosslinking treatment). Then, while immersing the layered body in an aqueous solution of boric acid at a liquid temperature of 70°C (an aqueous solution obtained by mixing 4 parts by weight of boric acid and 5 parts by weight of potassium iodide with respect to 100 parts by weight of water), rolls with different peripheral speeds Uniaxial stretching is performed between the cylinders so that the total stretching magnification in the longitudinal direction (longitudinal) is 5.5 times (underwater stretching treatment). Then, the layered body was immersed in a washing bath (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) having a liquid temperature of 30°C (washing treatment). Through the above, an optical thin film laminate containing a polarizer with a thickness of 5 μm was obtained.

(Production of protective film) Protective film: A (meth)acrylic resin film having a lactone ring structure with a thickness of 40 μm is corona treated and used.

(Applicable to the production of adhesives for protective films) 40 parts by weight of N-hydroxyethyl acrylamide (HEAA), 60 parts by weight of acryloyl mopholine (ACMO) and photoinitiator "IRGACURE 819" (BASF Made by the company) 3 parts by weight are blended to prepare an ultraviolet curable adhesive.

<Preparation of single-sided protective polarizing film> On the surface of the polarizing film of the optical film laminate, the ultraviolet curable adhesive is applied so that the thickness of the adhesive layer after curing becomes 0.5 μm, and the above Protect the film, and then irradiate ultraviolet rays as active energy rays to harden the adhesive. Ultraviolet rays are irradiated using a gallium-enclosed metal halide lamp, irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., bulb: V bulb, peak illuminance: 1600 mW/cm ² , and cumulative irradiation amount 1000/mJ/cm2 (wavelength 380 ~440nm), and the illuminance of the ultraviolet rays is measured using the Sola-Check system manufactured by Solarell. Next, the amorphous PET substrate was peeled off to produce a single-sided protective polarizing film A using a thin polarizing film. The optical properties of the obtained single-sided protective polarizing film were 42.8% transmittance and 99.99% polarization.

<Anchor coating layer forming material: polyvinyl alcohol resin composition> 100 parts of polyvinyl alcohol resin with a degree of polymerization of 2500 and a degree of saponification of 99.7 mol% and methylol melamine (manufactured by DIC Corporation, trade name "WATER SOL: S-695") 5 parts are dissolved in pure water to prepare an aqueous solution with a solid content concentration of 4% by weight.

<Preparation of acrylic polymer> In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube, and a cooler, a monomer mixture containing 99 parts of butyl acrylate and 1 part of 2-hydroxyethyl acrylate was charged . Then, 0.1 parts of 2,2´-azobisisobutyronitrile as a polymerization initiator and ethyl acetate were put into 100 parts of the aforementioned monomer mixture (solid content), and nitrogen was introduced while stirring slowly. After the nitrogen substitution, the liquid temperature in the flask was maintained at about 60°C, and the polymerization reaction was performed for 7 hours. After that, ethyl acetate was added to the resulting reaction liquid to prepare an acrylic polymer solution whose solid content was adjusted to a concentration of 30% and a weight average molecular weight of 1.4 million.

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

(Formation of Adhesive Layer) Next, the surface of the polyethylene terephthalate film (separation film) treated with a silicone release agent is uniformly coated with the above acrylic adhesive solution. Dry in a circulating constant temperature oven for 2 minutes to form an adhesive layer with a thickness of 20 μm on the surface of the separation film.

Example 1 <Preparation of a single-sided protective polarizing film with anchor coating layer> On the surface of the polarizing film (polarizer) of the single-sided protective polarizing film (the side of the polarizer without the protective film), the thickness after drying After coating the above-mentioned polyvinyl alcohol resin composition adjusted to 25°C with a wire bar coater so that it becomes 1μm, it is dried with hot air at 90°C for 20 seconds to produce a single-sided protective polarizing film with an anchor coating layer .

(Production of Polarizing Film with Adhesive Layer) Next, the adhesive layer formed on the release-treated surface of the release sheet (separator) is attached to the anchor formed on the single-sided protective polarizing film On the coating layer, to make a polarizing film with an adhesive layer.

Examples 2 to 11, Comparative Examples 1 to 6 The type of water-based resin blended with the anchor coating layer in Example 1 and the blending amount of methylol melamine (the blending amount is relative to 100 parts of water-based resin The type and blending amount of the silane coupling agent and crosslinking agent in the adhesive composition (the blending part is the value relative to 100 parts of the acrylic polymer) is changed as shown in Table 1, in addition to In the same manner as in Example 1, a single-sided protective polarizing film with an anchor coating layer and a polarizing film with an adhesive layer were produced.

The following evaluations were performed on the polarizing films with adhesive layers obtained in the above-mentioned Examples and Comparative Examples. The results are shown in Table 1.

<Measurement of initial gel fraction> Approximately 0.1 g of the adhesive layer formed on the release treatment surface of the separation film within 1 minute of production was picked up as sample 1. After wrapping the aforementioned sample 1 in a 0.2 μm diameter Teflon (registered trademark) film (trade name "NTF1122", manufactured by Nitto Denko Co., Ltd.), a kite string was tied to prepare sample 2. The weight of sample 2 was measured before being used for the following test, and this was referred to as weight A. The aforementioned weight A is the total weight of sample 1 (adhesive layer), Teflon (registered trademark) film and kite string. In addition, the total weight of the aforementioned Teflon (registered trademark) film and the kite string is referred to as weight B. Next, the aforementioned sample 2 was put into a 50 ml container filled with ethyl acetate, and allowed to stand at 23°C for 1 week. After that, the sample 2 was taken out of the container, and the ethyl acetate was dried in a dryer at 130°C for 2 hours, and then the weight of the sample 2 was measured. The weight of sample 2 after the aforementioned test was measured, and this was taken as weight C. Then calculate the gel fraction from the following formula. Gel fraction (weight%) = (C-B)/(A-B)×100 The initial gel fraction of the adhesive layer is preferably 80% or more. The low gel fraction is related to easy residual defects such as scratches.

<Anchor power> The polarizing film with the adhesive layer obtained in the Examples and Comparative Examples was cut into a size of 25mm×150mm, and the adhesive layer was deposited on the surface of the 50μm thick polyethylene terephthalate film. The vapor-deposited film of indium-tin oxide is bonded so that the vapor-deposited surfaces are in contact with each other. Then, one side of the aforementioned polyethylene terephthalate film was peeled off by hand, and after confirming that the adhesive layer was attached to the side of the polyethylene terephthalate film, the tensile tester AG-1 manufactured by Shimadzu Corporation was used to measure 180 The stress (N/25mm) (25°C) when peeling off at a speed of 300mm/min in the ° direction. If the anchoring force is above 15N/25mm, it is good that there is no residual glue during heavy work or there is no less glue or degumming during processing. In addition, the failure state at the time of peeling is represented by "cohesive failure (destruction of the anchor coating layer or adhesive layer)" or "interface peeling (peeling at the interface between the anchor coating layer and the adhesive layer)". In addition, in Comparative Example 7, only the isocyanate-based crosslinking agent was used as the crosslinking agent of the adhesive layer, so it was the anchoring force measured after 48 hours of aging. The examples and other comparative examples are the values measured within 24 hours (without aging) after forming the polarizing film with the adhesive layer.

【Table 1】

唑啉基之聚合物：EPOCROS WS-700((股)日本觸媒製)； 聚胺甲酸酯系樹脂：Takelac W-6020(三井化學聚胺酯(股)製)； 環氧樹脂：Celloxide 2021P((股)DAICEL製)。In Table 1, the peroxide represents the trade name: Nyper BMT 40SV, benzyl peroxide, manufactured by Nippon Oil & Fat Co., Ltd.; the isocyanate represents the trade name: TAKENATE D110N, trimethylolpropane of xylylene diisocyanate Adduct, manufactured by Mitsui Chemicals Co., Ltd.; X-41-1810: oligomer type sulfhydryl-containing silane coupling agent, alkoxy content: 30% by weight, mercapto group equivalent: 450g/mol, Shin-Etsu Chemical Co., Ltd. KBM-802: monomeric sulfhydryl-containing silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.; KBM-803: monomeric sulfhydryl-containing silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.; X-41- 1056: oligomer type epoxy-containing silane coupling agent, alkoxy content: 17% by weight, epoxy equivalent: 280g/mol, Shin-Etsu Chemical Co., Ltd. In addition, the crosslinking agent of Example 10 is a combined system of an isocyanate-based crosslinking agent and a peroxide crosslinking agent. With

Oxazoline-based polymer: EPOCROS WS-700 (manufactured by Nippon Shokubai Co., Ltd.); polyurethane resin: Takelac W-6020 (manufactured by Mitsui Chemicals Polyurethane Co., Ltd.); epoxy resin: Celloxide 2021P( (Share) DAICEL system).

1‧‧‧Polarizer 2‧‧‧Anchor coating layer (based on polyvinyl alcohol resin) 3‧‧‧Adhesive layer 4‧‧‧Separation piece 5. 5´‧‧‧Protective film 10‧‧‧Polarizing film with adhesive layer 11‧‧‧Polarizing film with adhesive layer

Fig. 1 is an example of a schematic cross-sectional view of a polarizing film with an adhesive layer of the present invention. 2 is an example of a schematic cross-sectional view of the polarizing film with an adhesive layer of the present invention. 3 is an example of a schematic cross-sectional view of the polarizing film with an adhesive layer of the present invention.

1‧‧‧Polarizer

2‧‧‧Anchor coating layer (based on polyvinyl alcohol resin)

3‧‧‧Adhesive layer

4‧‧‧Separation piece

10‧‧‧Polarizing film with adhesive layer

Claims (18)

A polarizing film with an adhesive layer, characterized in that: the polarizing film with an adhesive layer has a polarizer, an anchor coating layer and an adhesive layer in sequence, and the anchor coating layer is formed of a water-based resin composition , The water-based resin composition contains water-based resin and methylol melamine, the aforementioned adhesive layer is formed of an adhesive composition, and the adhesive composition contains a hydroxyl-containing base polymer and a mercapto-containing silane coupling agent. The polarizing film with an adhesive layer of claim 1, wherein the aforementioned water-based resin is selected from polyvinyl alcohol-based resins, polyurethane-based resins, epoxy-based resins, and

At least one of the oxazoline-based polymers. The polarizing film with an adhesive layer of claim 2, wherein the water-based resin is a polyvinyl alcohol-based resin. Such as the polarizing film with an adhesive layer of claim 3, wherein the saponification degree of the polyvinyl alcohol-based resin is 96 mol% or more and the average degree of polymerization is 2000 or more. The polarizing film with an adhesive layer according to claim 1, wherein the aqueous resin composition contains 0.2 to 20 parts by weight of the methylol melamine relative to 100 parts by weight of the aqueous resin. The polarizing film with an adhesive layer according to claim 1, wherein the thickness of the anchor coating layer is 0.05 μm or more and 6 μm or less. The polarizing film with an adhesive layer according to claim 1, wherein the aforementioned base polymer having hydroxyl group is a (meth)acrylic polymer having hydroxyl group. According to claim 1, the polarizing film with an adhesive layer, wherein the adhesive composition contains 0.01 to 5 parts by weight of the mercapto group-containing silane coupling agent relative to 100 parts by weight of the hydroxyl-containing base polymer. The polarizing film with an adhesive layer of claim 1, wherein the adhesive composition contains a crosslinking agent. The polarizing film with an adhesive layer according to claim 9, wherein the aforementioned crosslinking agent contains a crosslinking agent (b) that does not react with a hydroxyl group. The polarizing film with an adhesive layer according to claim 10, wherein the crosslinking agent (b) that does not react with the hydroxyl group is peroxide. For example, the polarizing film with an adhesive layer of claim 10, which contains 0.01 to 2 parts by weight of the crosslinking agent (b) that does not react with the hydroxyl group relative to 100 parts by weight of the aforementioned hydroxyl-containing base polymer. The polarizing film with an adhesive layer according to claim 1, wherein the thickness of the aforementioned polarizing member is 15 μm or less. For example, the polarizing film with an adhesive layer of claim 1, which is structured so that the optical properties of the aforementioned polarizer represented by the monomer transmittance T and the degree of polarization P satisfy the condition of the following formula: P>-(10 ^{0.929T -42.4} -1)×100 (only T<42.3), and P≧99.9 (only T≧42.3). The polarizing film with an adhesive layer according to claim 1, wherein a protective film is provided on at least one side of the aforementioned polarizing member. An adhesive layer-attached polarizing film according to any one of claims 1 to 15, wherein a separator is laminated on the adhesive layer. A manufacturing method of polarizing film with adhesive layer, It is characterized in that the polarizing film with the adhesive layer is as described in any one of claims 1 to 16, and the method includes the following steps: forming an anchor coating layer, coating a water-based resin on the polarizer The composition is then dried to form an anchor coating layer, wherein the water-based resin composition includes water-based resin and methylol melamine; the step of forming an adhesive layer is composed of an adhesive composition on the anchor coating layer An adhesive layer is formed, wherein the adhesive composition contains a base polymer with a hydroxyl group and a silane coupling agent containing a mercapto group. An image display device having a polarizing film with an adhesive layer as claimed in any one of claims 1 to 16.

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