TWI725141B - Manufacturing method of single-sided protective polarizing film with transparent resin layer, manufacturing method of polarizing film with adhesive layer, and manufacturing method of image display device - Google Patents

Abstract

The present invention is a manufacturing method of a single-sided protective polarizing film with a transparent resin layer, characterized in that the single-sided protective polarizing film with a transparent resin layer has a single-sided protective polarizing film with a protective film on only one side of the polarizer, and The transparent resin layer is provided on the surface of the polarizer of the aforementioned single-sided protective polarizing film, and the manufacturing method sequentially includes the following steps: Step (1), preparing a single-sided protective polarizing film with a protective film on only one side of the polarizer Step (2), coating the surface of the polarizer of the aforementioned single-sided protective polarizing film with an aqueous coating solution containing resin components; and step (3), drying the resulting coating film to form a transparent resin layer; and, the aforementioned polarizing film The material contains polyvinyl alcohol resin and has a thickness of 10 μm or less. The deviation of the water contact angle of the surface on which the transparent resin layer of the aforementioned polarizer is to be formed is within the range of the average water contact angle ±20°. According to the present invention, even when a single-sided protective polarizing film with a transparent resin layer using a thin polarizer is exposed to a humidified environment, the occurrence of uneven appearance defects can be suppressed.

Description

Manufacturing method of single-sided protective polarizing film with transparent resin layer, manufacturing method of polarizing film with adhesive layer, and manufacturing method of image display device

The invention relates to a method for manufacturing a single-sided protective polarizing film with a transparent resin layer. In addition, the present invention relates to a method for manufacturing a polarizing film containing the aforementioned single-sided protective polarizing film with a transparent resin layer and an adhesive layer with an adhesive layer. In addition, the present invention relates to a method for manufacturing an image display device such as a liquid crystal display device (LCD) or an organic EL display device, the image display device uses the single-sided protective polarizing film with a transparent resin layer obtained by the foregoing manufacturing method or Polarizing film with adhesive layer.

The market for liquid crystal display devices for applications such as clocks, mobile phones, PDAs, notebook computers, computer monitors, DVD players, and TVs is rapidly expanding. The liquid crystal display device visualizes the polarization state through switching of the liquid crystal, and uses a polarizer based on its display principle.

As a polarizer, because of its high transmittance and high degree of polarization, the iodine-based polarizer is the most widely used, for example, a structure formed by making polyvinyl alcohol adsorb iodine and stretch it. This kind of polarizer has the shortcomings of extremely weak mechanical strength and shrinkage due to heat or moisture, resulting in a significant reduction in the polarizing function. Therefore, the prepared polarizer is immediately bonded to the protective film coated with the adhesive through the adhesive to form a polarizing film for use.

On the other hand, image display devices such as liquid crystal display devices have advanced toward thinning, and thinning of polarizing films is also being required. Therefore, thinning is also being developed in terms of polarizers. In addition, it can be thinned by using a single-sided protective polarizing film, which only has a protective film on one side of the polarizer, and no protective film on the other side. This type of single-sided protective polarizing film is thinner than the two-sided protective polarizing film in which both sides of the polarizer are provided with protective films, because there is less protective film.

On the other hand, a single-sided protective polarizing film has insufficient durability against thermal shock, so it has been proposed to provide a protective layer (transparent resin layer) on the side of the polarizer (for example, refer to Patent Documents 1 and 2).

Prior Art Documents Patent Documents Patent Document 1: Japanese Patent Publication No. 2010-009027 Patent Document 2: Japanese Patent Publication No. 2013-160775

The problem to be solved by the invention As mentioned above, it is known that the durability of the single-sided protective polarizing film can be improved by forming a transparent resin layer on the polarizer. However, a new discovery was made this time. When a single-sided protective polarizing film using a thin polarizer with a thickness of 10μm or less has a transparent resin layer formed on the polarizer, the single-sided protective polarizing film with a transparent resin layer When exposed to a humidified environment, the single-sided protective polarizing film with a transparent resin layer after the humidification test is attached to both sides of an image display panel, etc. with the absorption axis perpendicularly intersecting. Uneven appearance defects were found.

Therefore, the object of the present invention is to provide a method for manufacturing a single-sided protective polarizing film with a transparent resin layer, even when the single-sided protective polarizing film with a transparent resin layer using a thin polarizer is exposed to a humidified environment In the case of, it can still suppress the occurrence of uneven appearance defects. In addition, the object of the present invention is also to provide a method for manufacturing a polarizing film with an adhesive layer using the aforementioned single-sided protective polarizing film with a transparent resin layer, and a single-sided protective polarizing film using the aforementioned transparent resin layer or Method for manufacturing image display device with polarizing film with adhesive layer.

Means for Solving the Problem After careful research by the inventors of the present case, they found that the above-mentioned problem can be solved by the following manufacturing method of a single-sided protective polarizing film with a transparent resin layer, and finally completed the present invention.

That is, the present invention relates to a manufacturing method of a single-sided protective polarizing film with a transparent resin layer, characterized in that: the single-sided protective polarizing film with a transparent resin layer has a single side with a protective film on only one side of the polarizer. The surface protection polarizing film, and the transparent resin layer that has been set on the surface of the polarizing member of the single-sided protection polarizing film, and the manufacturing method includes the following steps in sequence: Step (1), preparing to protect only one side of the polarizing member The single-sided protective polarizing film of the film; step (2), coating the surface of the polarizer of the aforementioned single-sided protective polarizing film with an aqueous coating liquid containing resin components; and step (3), drying the obtained coating film to form a transparent Resin layer; and, the polarizer contains polyvinyl alcohol resin and has a thickness of 10 μm or less, and the deviation of the water contact angle of the surface of the polarizer on which the transparent resin layer is to be formed is within the range of the average water contact angle ±20°.

Before the step (2) of applying the water-based coating liquid, the following steps may be included in sequence: laminating a surface protective film on the polarizer side of the single-sided protective polarizing film, and then removing the surface protective film from the single side The protective polarizing film is peeled off; and, an activation treatment is applied to the peeling surface of the surface protective film of the single-sided protective polarizing film.

Before the step (2) of applying the water-based coating liquid, the following steps may be sequentially included: applying activation treatment to the surface of the polarizer of the single-sided protective polarizing film; and, applying the activation treatment to the surface of the single-sided protective polarizing film A surface protective film is attached to the activated surface, and then the surface protective film is peeled off from the single-sided protective polarizing film.

The aforementioned activation treatment is preferably corona treatment and/or plasma treatment.

The deviation of the aforementioned water contact angle should be within ±15° of the average water contact angle.

The aforementioned average water contact angle is preferably 90° or less.

In addition, the present invention relates to a method for manufacturing a polarizing film with an adhesive layer, which is characterized by having the following steps: forming on the transparent resin layer of the single-sided protective polarizing film with a transparent resin layer obtained by the foregoing manufacturing method Adhesive layer.

Furthermore, the present invention relates to a method of manufacturing an image display device, characterized in that it uses the single-sided protective polarizing film with a transparent resin layer obtained by the foregoing manufacturing method, or the adhesive layer obtained by the foregoing manufacturing method. Polarizing film is formed.

Effects of the Invention The method for manufacturing a single-sided protective polarizing film with a transparent resin layer of the present invention can provide a single-sided protective polarizing film with a transparent resin layer, even though thin polarizers are used, even when exposed to humidification Under environmental conditions, it can still suppress the occurrence of uneven appearance defects.

This cover is because the deviation value of the water contact angle of the transparent resin layer forming surface of the polarizer used in the present invention is controlled within a predetermined range, so that the thickness unevenness of the transparent resin layer is suppressed. That is, when a single-sided protective polarizing film with a transparent resin layer has been exposed to a humidified environment, the components near the surface of the polarizer may sometimes penetrate into the transparent resin layer. In this case, if a thickness of 10μm or less is used For polarizers, it is conceivable that the proportion of the components that penetrate into the transparent resin layer relative to the total amount of the polarizer is high, and when the thickness of the transparent resin layer is uneven, it will lead to the amount of components that permeate from the polarizer into the transparent resin layer It is also uneven, so it becomes easy to visually recognize uneven appearance defects.

In addition, the manufacturing method of the image display device of the present invention uses the single-sided protective polarizing film with a transparent resin layer or the polarizing film with an adhesive layer obtained by the manufacturing method of the present invention, so it can provide a highly reliable image display Device.

1. The manufacturing method of a single-sided protective polarizing film with a transparent resin layer The manufacturing method of a single-sided protective polarizing film with a transparent resin layer of the present invention is characterized in that the single-sided protective polarizing film with a transparent resin layer A single-sided protective polarizing film with a protective film on one side of the piece, and a transparent resin layer that has been set on the surface of the polarizing piece of the single-sided protective polarizing film, and the manufacturing method sequentially includes the following steps: Step (1), Prepare a single-sided protective polarizing film with a protective film on only one side of the polarizer; step (2), coating the surface of the polarizer of the single-sided protective polarizing film with a water-based coating liquid containing a resin component; and step (3), The obtained coating film is dried to form a transparent resin layer; and the polarizer contains polyvinyl alcohol resin and has a thickness of 10 μm or less, and the deviation of the water contact angle of the surface on which the transparent resin layer of the polarizer is to be formed is in the average water contact The angle is within ±20°.

The aforementioned single-sided protective polarizing film with a transparent resin layer will be described with reference to FIG. 1. However, the present invention is not limited by these figures.

The single-sided protective polarizing film 3 used in the present invention has a protective film 2 on only one side of the polarizer 1. The aforementioned polarizer 1 and the protective film 2 may be laminated via an intermediary layer (not shown) such as an adhesive layer, an adhesive layer, and a primer layer (primer layer). The single-sided protective polarizing film 10 with a transparent resin layer obtained by the manufacturing method of the present invention does not have a transparent resin layer 4 on the polarizer surface of the aforementioned single-sided protective polarizing film 3 (the side of the polarizer 1 without the protective film 2).

Hereinafter, each step of the manufacturing method of the present invention will be described.

(1) Step of preparing a single-sided protective polarizing film (1) In step (1), a single-sided protective polarizing film 3 having a protective film 2 on only one side of the polarizer 1 is prepared.

The polarizer 1 having a thickness of 10 μm or less is used as the aforementioned polarizer 1. The thickness of the polarizer 1 is preferably 8 μm or less, preferably 7 μm or less, and more preferably 6 μm or less. On the other hand, the thickness of the polarizer is preferably 2 μm or more, preferably 3 μm or more. Such a thin polarizer 1 has less variation in thickness, excellent visibility (visibility), and low dimensional change, so it has excellent durability against thermal shock.

The polarizer 1 uses a polyvinyl alcohol-based resin. As the polarizer 1, for example, hydrophilic polymer films such as polyvinyl alcohol-based films, partially formalized polyvinyl alcohol-based films, ethylene-vinyl acetate copolymer-based partially saponified films, etc., adsorb iodine or dichroic dyes, etc. Dichroic materials and uniaxially stretched ones, and 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.

A polarizer made of polyvinyl alcohol-based film dyed with iodine and then uniaxially stretched can be produced, for example, in the following way: the polyvinyl alcohol film is immersed in an aqueous solution of iodine to dye, and then stretched to 3-7 of the original length. Times. It can also be immersed in aqueous solutions such as boric acid or potassium iodide that may contain zinc sulfate, zinc chloride, etc. according to needs. 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 cleaned. In addition, it also has the effect of swelling the polyvinyl alcohol-based film to prevent uneven dyeing and other defects. 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.

In terms of extension stability or optical durability, the polarizing member 1 preferably contains boric acid. In addition, the content of boric acid contained in the polarizer 1 is preferably 25% by weight or less, and preferably 20% by weight or less, relative to the total amount of the polarizer, from the viewpoint of suppressing the occurrence of through cracks and nano-slits and suppressing expansion. , 18% by weight or less is more preferable, and 16% by weight or less is particularly preferable. On the other hand, from the viewpoint of the extension stability or optical durability of the polarizer 1, the boric acid content relative to the total amount of the polarizer is preferably 10% by weight or more, and more preferably 12% by weight or more.

The aforementioned polarizer 1 should be constructed such that the optical characteristics shown by the monomer transmittance T and the degree of polarization P satisfy the conditions of the following formula: P>-(100.929T-42.4-1)×100 (but T<42.3), or P≧99.9 (but T≧42.3). A polarizer configured to satisfy the aforementioned conditions will undoubtedly have 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 uses, it can be attached to the viewing side of an organic EL display device, for example.

The material constituting the protective film 2 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; cellulosic polymers such as cellulose diacetate and cellulose triacetate; acrylic acid such as polymethyl methacrylate -Based polymers; styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin); and polycarbonate-based polymers. In addition, the following polymers can also be cited as examples of 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-based polymers, polyether ether ketone-based 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.

In addition, the protective film 2 may contain one or more arbitrary appropriate additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, coloring inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, colorants, and the like. The content of the above-mentioned thermoplastic resin in the protective film is preferably 50-100% by mass, preferably 50-99% by mass, more preferably 60-98% by mass, and particularly preferably 70-97% by mass. When the content of the above-mentioned thermoplastic resin in the protective film 2 is less than 50% by mass, the high transparency originally possessed by the thermoplastic resin may not be fully exhibited.

The aforementioned protective film 2 may also use a retardation film, a brightness enhancement film, a diffusion film, and the like. 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 above-mentioned 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 2 can be appropriately set, but in general, it is preferably 3 to 200 μm, and more preferably 3 to 100 μm from the viewpoints of workability such as strength and handleability, and thin layer properties. In particular, the thickness of the protective film (when a film is formed in advance) is preferably 10 to 60 μm, and more preferably 10 to 50 μm from the viewpoint of transportability. On the other hand, the thickness of the aforementioned protective film (when formed by coating and hardening) is preferably 3 to 25 μm in terms of transportability, and more preferably 3 to 20 μm. The aforementioned protective film may use multiple sheets or multiple layers.

The surface of the protective film 2 that is not bonded to the polarizer 1 can be provided with functional layers such as a hard coating, an anti-reflection layer, an anti-adhesion layer, a diffusion layer and an anti-glare layer. 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 individual.

The aforementioned protective film 2 and the polarizer 1 can be laminated via an intermediary layer such as an adhesive layer, an adhesive layer, and a primer. At this time, it is ideal to use an interposer to laminate the two without air gaps. In addition, the interposer between the polarizer 1 and the protective film 2 is not shown in the figure.

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 type adhesive is an adhesive that is hardened with active energy rays such as electron beams and ultraviolet rays (radical hardening type, cation hardening type). For example, electron beam 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 the photoradical curable active energy ray curable adhesive is used as the ultraviolet curable adhesive, the adhesive contains a radical polymerizable compound and a photopolymerization initiator.

The coating method of the adhesive is appropriately selected according to the viscosity and target thickness of the adhesive. Examples of coating methods include: reverse coater, gravure coater (direct, reverse or offset), bar reversal coater, roll coater, mold coater, bar coater, bar Type coating machine, etc. In addition, a dipping method or the like can be suitably used for coating.

In addition, when the aforementioned adhesive is applied using a water-based adhesive, etc., 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 150 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 0.2 to 20 μm.

In addition, when the polarizer 1 and the protective film 2 are laminated, an easy bonding layer may be provided between the protective film and the adhesive layer. The easy bonding layer, for example, can be formed by various resins having the following skeletons: polyester skeleton, polyether skeleton, polycarbonate skeleton, polyurethane skeleton, polysiloxane, polyamide skeleton, polyamide Imine skeleton, polyvinyl alcohol skeleton, etc. These polymer resins can be used individually by 1 type or in combination of 2 or more types. In addition, other additives may be added in the formation of the easy-to-bond layer. Specific examples include stabilizers such as adhesion imparting agents, ultraviolet absorbers, antioxidants, and heat-resistant stabilizers.

The easy-adhesive layer is usually set on the protective film in advance, and the easy-adhesive layer side of the protective film and the polarizer are laminated with the adhesive layer. The formation of the easy-adhesive layer is carried out by coating the easy-adhesive layer forming material on the protective film by a conventional technique and drying. The easy-adhesive layer forming material is usually prepared as a solution, which is diluted to an appropriate concentration in consideration of the thickness after drying, the smoothness of the coating, and the like. The thickness of the easy-adhesive layer after drying is preferably 0.01-5 μm, more preferably 0.02-2 μm, and more preferably 0.05-1 μm. In addition, the easy-adhesive layer can be provided with multiple layers, but in this case, it is still preferable to keep the total thickness of the easy-adhesive layer within the above range.

The adhesive layer is formed of an adhesive. Various adhesives can be used for the adhesive, such as rubber adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinylpyrrole Pyridone-based adhesives, polyacrylamide-based adhesives, cellulose-based adhesives, etc. The adhesive base polymer can be selected according to the types of the aforementioned adhesives. Among the aforementioned adhesives, it is preferable to use an acrylic adhesive in terms of excellent optical transparency, exhibiting suitable adhesive properties such as wettability, cohesiveness, and adhesiveness, and excellent weather resistance and heat resistance.

The primer layer (primer layer) is formed to improve the adhesion between the polarizer 1 and the protective film 2. The material constituting the primer layer is not particularly limited as long as it can exert a certain degree of strong adhesion to both the polarizer 1 and the protective film 2. For example, a thermoplastic resin excellent in transparency, thermal stability, extensibility, etc. can be used. Examples of thermoplastic resins include acrylic resins, polyolefin resins, polyester resins, polyvinyl alcohol resins, or mixtures thereof.

The single-sided protective polarizing film 3 used in the present invention can be prepared by the manufacturing method of the single-area layer protective film 2 of the polarizer 1, but the specific manufacturing method is preferably, for example, a manufacturing method including the following steps: Step (1-1), forming a laminate (a), which has a transport film and a polarizer 1 with a thickness of 10 μm or less, the polarizer 1 containing polyvinyl alcohol resin formed on one side of the transport film; (1-2), forming a protective film 2 on the polarizer 1 side of the layered body (a) obtained in the foregoing step (1-1); and, step (1-3), the layered body obtained from the foregoing step (1-2) (Protective film 2 / Polarizer 1 / Transport film) The transport film is peeled off. Hereinafter, each step of the aforementioned preferred manufacturing method will be described.

(1-1) Step of forming laminate (a) (1-1) The aforementioned laminate (a), for example, can be obtained by combining a transport film and a polyethylene that has been formed on one side of the transport film. A laminate (a´) of alcohol resin (hereinafter also referred to as PVA resin) layers is obtained by subjecting at least an elongation step and a dyeing step. The aforementioned transport film can be formed into a long PVA-based resin layer by using a long object, which is advantageous for continuous production.

As the transport film, various thermoplastic resin films can be used. Examples of materials for forming thermoplastic resin films include ester resins such as polyethylene terephthalate resins, cycloolefin resins such as norbornene resins, olefin resins such as polyethylene and polypropylene, and polyamide resins. , Polycarbonate resins, copolymer resins etc. etc. Among them, from the viewpoints of ease of manufacture and cost reduction, ester-based resins are preferred. As the ester-based thermoplastic resin film, an amorphous ester-based thermoplastic resin film or a crystalline ester-based thermoplastic resin film can be used. In addition, the thickness of the aforementioned thermoplastic resin film is preferably thicker in view of the avoidance of cracks during the stretching step and the ease of transportation of the laminate (a). Generally speaking, the thickness before the stretching step is preferably 20 to 200 μm. , 30~150μm is preferred.

In addition, as the transport film, a peelable adhesive layer can be used on the thermoplastic resin film. For the adhesive layer, the same thing as that used for the surface protection film mentioned later can be used.

The polarizer in the aforementioned laminate (a) contains a polyvinyl alcohol-based resin and has a thickness of 10 μm or less. The appropriate range of the thickness of the polarizer or the polyvinyl alcohol-based resin is the same as described above. Such a thin polarizer 1, in step (1-3), when the transport film is peeled from the aforementioned laminate (a), sometimes defects are easily generated on the surface of the thin polarizer 1, so that the polarizer 1 The surface condition of the transparent resin layer 4 forming surface has uneven defects.

As a thin polarizer, representative examples include Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, International Publication No. 2014/077599, International Publication The thin polarizer described in the manual No. 2014/077636, etc., or the thin polarizer obtained by the manufacturing method described in the same.

As the aforementioned thin polarizer, in the manufacturing method including the stretching step and the dyeing step in the state of a layered body (a´), in terms of high-magnification stretching and improved polarization performance, it is preferably as in Japanese Patent No. 4751486 The specification, Japanese Patent No. 4751481, and Japanese Patent No. 4815544 generally include the step of extending in an aqueous solution of boric acid as described in the specification, especially those described in Japanese Patent No. 4751481 and Japanese Patent No. 4815544 It includes those obtained from the preparation method of performing an auxiliary aerial stretching step before stretching in an aqueous solution of boric acid. These thin polarizing films can be obtained by a manufacturing method including a stretching step and a dyeing step, and the stretching step is to stretch the polyvinyl alcohol-based resin layer and the stretching transport film in the state of a laminate. According to such a manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without failures such as breakage due to stretching by being supported by a conveying film for stretching.

The aforementioned laminate (a´) can be formed by, for example, coating a PVA-based resin aqueous solution on a transport film and then drying it. In addition, the PVA-based resin layer in the aforementioned laminate (a´) can be formed on the transport film by an extrusion molding method. In addition, the aforementioned PVA-based resin layer may also be formed by laminating a pre-prepared PVA-based resin film on a transport film. The thickness of the aforementioned PVA-based resin layer can be appropriately determined in consideration of the stretching ratio, etc., so that the thickness of the polarizer obtained after stretching is 10 μm or less. In addition, if the PVA-based resin film is dyed in advance, the dyeing step applied to the laminate (a') can be omitted.

The stretching step performed on the aforementioned laminate (a'), for example, is preferably performed so that the total stretching ratio of the PVA-based resin layer is in the range of 3 to 10 times the total stretching ratio. The total extension ratio is preferably 4 to 8 times, and 5 to 7 times is better. It is preferable to make the total stretching ratio of 5 times or more. The aforementioned extension step can also be implemented in the dyeing step or other steps. When stretching is performed in steps other than the stretching step, the aforementioned total stretching magnification refers to the cumulative stretching magnification of the stretching when these steps are included.

The dyeing step performed on the aforementioned laminate (a') is performed by adsorbing and aligning dichroic dye or iodine on the PVA-based resin layer. The dyeing step can be parallel to the extension step. The dyeing step is generally performed by, for example, immersing the laminate (a') in an iodine solution for an arbitrary period of time. As the iodine aqueous solution used as the iodine solution, an aqueous solution in which iodine ions are contained by using iodine and an iodine compound as a dissolution aid can be used. As the iodine compound, for example, potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, titanium iodide, etc. can be used. As the iodine compound, potassium iodide is suitable. The iodine compound used in the present invention is also the same as above when used in other steps.

The iodine concentration in the aforementioned iodine solution is about 0.01 to 10% by weight, preferably 0.02 to 5% by weight, and more preferably 0.02 to 0.5% by weight. The concentration of the iodine compound is about 0.1-10% by weight, and preferably 0.2-8% by weight. During iodine dyeing, the temperature of the iodine solution is usually around 20~50°C, and preferably 25~40°C. The immersion time is usually about 10 to 300 seconds, and preferably in the range of 20 to 240 seconds.

Furthermore, in addition to the above-mentioned steps, the laminate (a') may be subjected to, for example, an insolubilization step, a crosslinking step, a drying (water content adjustment) step, and the like.

In the insolubilization step and the cross-linking step, a boron compound can be used as a cross-linking agent. The order of these steps is not particularly limited. The cross-linking step can be parallel to the dyeing step and the extension step. The insolubilization step and the cross-linking step can be implemented multiple times. Examples of boron compounds include boric acid and borax. The boron compound is generally used in the form of an aqueous solution or a water-organic solvent mixed solution. An aqueous solution of boric acid is usually used. The boric acid concentration of the boric acid aqueous solution is about 1-10% by weight, and preferably 2-7% by weight. In terms of imparting heat resistance by the degree of crosslinking or suppressing damage when the transport film is peeled off, it is preferable to use the aforementioned boric acid concentration. The boric acid aqueous solution or the like may contain iodine compounds such as potassium iodide. When the boric acid aqueous solution contains an iodine compound, the concentration of the iodine compound is about 0.1 to 10% by weight, and preferably 0.5 to 8% by weight.

(1-2) Step of forming a protective film (1-2) In the foregoing step (1-2), the protective film 2 is formed on the polarizer 1 side of the laminate (a) obtained above. Through this step (1-2), a single-sided protective polarizing film A'with a transport film having a protective film 2 on only one side of the polarizer 1 can be produced. Regarding the protective film 2 and the interposer used when the protective film 2 is laminated, the aforementioned substances can be used.

(1-3) The step of peeling off the transport film (1-3) The step (1-3) is to peel off the transport film from the single-sided protective polarizing film A'with the transport film. The peeling method of the film for conveyance is not specifically limited. When peeling the film for transportation, the corner of the polarizer 1 (or the single-sided protective polarizing film) side may be folded, or the side of the film for transportation may be folded for peeling. Moreover, it is also possible to fold corners on both sides for peeling. In any case, the thin polarizer 1 is likely to be damaged due to peeling of the transport film. The angle can be set arbitrarily when the transport film is peeled off. When peeling the transport film, there is an angle at which the peeling force is most weakened. The angle at which the peeling force becomes weaker depends on the "structure, peeling speed, humidity during peeling, and rigidity of the peeling film", so the angle can be appropriately determined.

(2) The step of applying the water-based coating liquid containing the resin component (2) The step (2) is for the single-sided protective polarizer prepared in the previous step (1) that has a protective film 2 on only one side of the polarizer 1 The film 3 is coated with an aqueous coating liquid containing a resin component on the surface of the polarizer 1. The surface of the polarizer 1 where the transparent resin layer 4 is to be formed is the surface of the single-sided protective polarizing film 3 obtained in the step (1) where the transport film has been peeled off.

The deviation value of the water contact angle of the surface of the polarizer 1 where the transparent resin layer 4 is to be formed (the surface of the polarizer 1 without the protective film 2) is within the range of the average water contact angle ±20°.

The aforementioned deviation value of the water contact angle means the deviation of the average water contact angle of each water contact angle measured at multiple locations in any position of the polarizer 1. Specifically, it means: among the arbitrary positions of the polarizer 1, measure the water contact angle at 25 points in the width direction of the polarizer 1, and measure the water contact angle at 5 points in the extension direction (conveying direction) of the polarizer 1, and calculate it The average value of the same (average water contact angle), and the measured water contact angles are within ±20° of the aforementioned average water contact angle. Therefore, for example, if the average value of the water contact angle measured in the width direction at any position of the polarizer 1 is 90°, it means that each water contact angle measured in the width direction is 90°± Within the range of 20°(70~110°). Moreover, this operation can be performed at any position of the polarizer 1. Here, the width direction of the polarizer 1 means a direction perpendicular to the extending direction (conveying direction) of the polarizer 1.

The deviation value of the aforementioned water contact angle is within the range of the average water contact angle ±20°, and the average water contact angle is preferably within the range of ±15°, and the average water contact angle is preferably within the range of ±10°. In the present invention, the deviation of the water contact angle of the surface of the polarizer 1 where the transparent resin layer 4 is to be formed (the surface of the polarizer 1 without the protective film 2) can be formed on the polarizer 1 The occurrence of unevenness in the thickness of the upper transparent resin layer 4 is suppressed, so even if it is exposed to a humidified environment, it is possible to suppress the recognition of unevenness in appearance.

The average water contact angle of the surface on which the transparent resin layer 4 of the aforementioned polarizer 1 is to be formed is not particularly limited, but from the viewpoint of affinity with the water-based coating liquid, it is preferably 90° or less, and 80° or less. 60° or less is better.

The aforementioned water contact angle of the surface of the polarizer 1 where the transparent resin layer 4 is to be formed can be appropriately controlled by the material of the polarizer 1 and various treatments. The various treatments will be described later.

The water-based coating liquid used in the present invention contains a resin component, and the transparent resin layer 4 is formed of the water-based coating liquid.

The aforementioned water-based coating liquid (hereinafter also referred to as a forming material) includes, for example, a coating liquid containing a resin component that has been dissolved or dispersed in water. The resin component that has been dissolved or dispersed in water refers to a resin that has been dissolved in water at room temperature (25°C), and a water-soluble resin is dissolved in an aqueous solvent. In the present invention, since a water-based coating liquid (water-based or water-dispersed) is used, the surface of the polarizer 1 whose water contact angle deviation value is controlled has excellent affinity. In addition, when there are damaged parts on the surface of the polarizer 1 (damaged parts appearing on the surface of the polarizer 1 before the transparent resin layer is formed), the aforementioned water-based coating liquid will be incorporated into the damaged parts by swelling on the surface of the polarizer 1. Therefore, it is advantageous. That is, by using the water-based coating liquid, the orientation of the polyvinyl alcohol molecules around the damaged part of the polarizer 1 can be partially reduced, and the boric acid content around the damaged part can be reduced. Therefore, the thickness of the transparent resin layer 4 can be reduced. Small (for example, less than 3 μm, or even better than 2 μm), can still effectively inhibit the expansion of the damaged area.

Representative examples of the aforementioned resin components include, for example, polyvinyl alcohol (PVA) resins, poly(meth)acrylic acid, polypropylene amides, methylolated melamine resins, methylolated urea resins, and resol-type phenol resins. , Polyethylene oxide, carboxymethyl cellulose, etc. These etc. can be used individually or in combination of multiple. The aforementioned resin component preferably uses polyvinyl alcohol-based resin, poly(meth)acrylic acid, and methylolated melamine. From the viewpoint of adhesion to the polyvinyl alcohol-based resin constituting the polarizer, the aforementioned resin component is particularly preferably a polyvinyl alcohol-based resin. The case where polyvinyl alcohol-based resin is used is described below.

The transparent resin layer 4 is preferably formed of a forming material (coating liquid) containing a polyvinyl alcohol-based resin. The polyvinyl alcohol-based resin forming the transparent resin layer may be "polyvinyl alcohol-based resin", and it may be the same as or different from the polyvinyl alcohol-based resin contained in the polarizer.

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. -Olefin, (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 may be used singly or in combination of two or more kinds.

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 99 mol% or more, more preferably 99.7 mol%. Ear% or more. The degree of saponification indicates 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 can be determined in accordance with JIS-K6726-1994.

The average degree of polymerization of the aforementioned polyvinyl alcohol-based resin can be, for example, 500 or more. However, from the viewpoint of satisfying moisture and heat resistance and water resistance, the average degree of polymerization is preferably 1000 or more, preferably 1500 or more, and more preferably 2000 or more. The average degree of polymerization of the polyvinyl alcohol-based resin is measured in accordance with JIS-K6726.

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

The ratio of the polyvinyl alcohol-based resin in the transparent resin layer 4 or the water-based coating liquid (solid content) is preferably 80% by weight or more, preferably 90% by weight or more, and more preferably 95% by weight or more.

The aqueous coating liquid is prepared to prepare a solution in which the polyvinyl alcohol-based resin is dissolved in an aqueous solvent.

Examples of the aforementioned water-based solvent include water, or a mixed solvent composed of water and a water-soluble organic solvent. Among them, a water-based solvent composed only of water is preferred. Examples of water include distilled water, ion exchange water, ultrapure water, and the like. Examples of water-soluble organic solvents include methanol, ethanol, acetone, 1-propanol, and 2-propanol. When the water-based solvent contains a water-soluble organic solvent, the content of the water-soluble organic solvent in the water-based solvent is preferably 40% by weight or less, preferably 20% by weight or less, and more preferably 10% by weight or less.

Although the concentration of the polyvinyl alcohol resin in the aforementioned forming material (such as an aqueous solution) is not particularly limited, if coating properties and storage stability are considered, it is preferably 0.1-15% by weight, and 0.5-10% by weight. good.

In addition, additives may be added to the aforementioned coating liquid (for example, an aqueous solution). Examples of the aforementioned additives include plasticizers and surfactants. Examples of the plasticizer include polyhydric alcohols such as ethylene glycol and glycerol. Examples of the surfactant include nonionic surfactants. In addition, it can also be matched with coupling agents such as silane coupling agent, titanium coupling agent, various adhesive excipients, ultraviolet absorbers, antioxidants, heat-resistant stabilizers, hydrolysis-resistant stabilizers and other stabilizers.

Among the aforementioned coating liquids, when there are damaged parts on the surface of the polarizer 1, the low-viscosity coating liquid tends to penetrate the damaged parts of the polarizer, which is advantageous. The aforementioned viscosity measured at 25°C is preferably 2000 mPa·s or less, 1000 mPa·s or less, 500 mPa·s or less, more preferably 100 mPa·s or less.

The application of the aforementioned water-based coating liquid to the side of the polarizer 1 of the single-sided protective polarizing film 3 should not be performed so that the thickness of the coating film (transparent resin layer 4) after drying is 0.2 μm or more. The thickness of the aforementioned transparent resin layer 4 is preferably 0.5 μm or more, more preferably 0.7 μm or more. On the other hand, if the transparent resin layer 4 becomes too thick, the optical reliability and water resistance will decrease. Therefore, the thickness of the transparent resin layer 4 is preferably 3 μm or less, preferably less than 3 μm, and more preferably 2 μm or less.

Various methods can be adopted for the coating method of the aforementioned coating liquid. 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 a mold coater, etc.

(3) Step (3) of forming a transparent resin layer In step (3), the coating film obtained in step (2) is dried to form a transparent resin layer 4.

The drying temperature is not particularly limited, and is usually about 60 to 150°C, preferably 80 to 120°C, and more preferably 90 to 120°C. Furthermore, the drying time is preferably 10 to 500 seconds, and more preferably 20 to 400 seconds.

In the manufacturing method of the present invention, since the deviation of the water contact angle of the surface of the polarizer 1 where the transparent resin layer 4 is to be formed is controlled within a specific range, a coating of a water-based coating liquid is formed on the surface of the polarizer 1 The occurrence of uneven film thickness defects of the transparent resin layer 4 obtained by filming and drying can be suppressed, and the appearance of unevenness defects can be suppressed in a humidified environment.

(4) Other steps In the manufacturing method of the single-sided protective polarizing film with a transparent resin layer of the present invention, it is preferable to include selected from the group consisting of the following steps before the step (2) of applying the aforementioned water-based coating liquid In this way, the deviation value of the water contact angle of the surface of the polarizer 1 where the transparent resin layer 4 is to be formed can be controlled: a surface protective film is attached to the polarizer surface of the single-sided protective polarizer film and then The surface protection film is peeled from the aforementioned single-sided protection polarizing film; and an activation treatment is applied.

(4-1) Steps of attaching and peeling surface protective film The aforementioned surface protective film usually has a base film and an adhesive layer, and the single-sided protective polarizing film 3 is protected via the adhesive layer. The surface protective film is a single-sided protective polarizing film for temporary protection of the adhesive layer, which is peeled off in actual use.

For the base film of the surface protection film, from the viewpoints of inspection and management, a thin film material with isotropic or nearly isotropic properties is selected. The film material may include, for example, polyester resins such as polyethylene terephthalate films, cellulose resins, acetate resins, polyether turpentine resins, polycarbonate resins, polyamide resins, etc. Transparent polymers like polyimide resins, polyolefin resins, and acrylic resins. Among them, polyester-based resins are preferred. 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 the base polymer. The adhesive is used as the adhesive to form the adhesive layer of the surface protection film. From the viewpoints of transparency, weather resistance, heat resistance, etc., an acrylic adhesive having an acrylic polymer as a base polymer is suitable. 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 surface of the base film opposite to the surface where the adhesive layer is provided, using low-adhesion materials such as silicone treatment, long-chain alkyl treatment, fluorine treatment, etc.

For the surface protection film, commercially available products can also be suitably used. For example, TORETEC 7832C #30 manufactured by Toray Film Processing Co., Ltd. can be suitably used.

In addition, the time from bonding the aforementioned surface protection film to peeling off the surface protection film is not particularly limited, but for example, 1 hour or more is preferable, and 12 hours or more is more preferable.

By attaching and peeling off the surface protection film on the polarizer 1 surface (the transparent resin layer 4 forming surface) of the single-sided protective polarizing film 3, the deviation of the water contact angle of the transparent resin layer 4 forming surface of the polarizer 1 can be suppressed The value is therefore better.

(4-2) Activation treatment step The aforementioned activation treatment may be corona treatment and/or plasma treatment. The above-mentioned corona treatment includes, for example, a method of performing electric discharge in atmospheric air using a corona treatment machine. The plasma treatment may be, for example, a method of performing discharge in atmospheric air using a plasma discharger.

The corona output effect of the aforementioned corona treatment is not limited, but for example, it is preferably about 0.5 to 8.0 kW, preferably about 0.5 to 7.0 kW, and more preferably about 0.5 to 6.0 kW.

The processing speed of the aforementioned corona treatment is preferably about 5 to 100 m/min, preferably about 5 to 90 m/min, and more preferably about 5 to 80 m/min.

The plasma output power in the aforementioned plasma processing is not particularly limited, but for example, it is preferably about 0.5 to 5.0 kW, preferably about 0.5 to 3.0 kW, and more preferably about 0.5 to 1.5 W.

The processing speed of the aforementioned plasma treatment is preferably about 5-100m/min, preferably about 5~90m/min, and more preferably about 5~80m/min.

When performing the aforementioned corona treatment or plasma treatment, the treatment can be performed once, but it is better to perform the treatment more than two times. In addition, both corona treatment and plasma treatment can be performed. For example, corona treatment is applied to the surface of the polarizer 1 (the surface where the transparent resin layer 4 is formed) of the single-sided protective polarizing film 3, and then plasma treatment is applied, and the treatment surface is coated with the water-based coating liquid. form.

We believe that the aforementioned corona treatment or plasma treatment will increase the hydrophilicity of the polarizer 1 surface (the surface where the transparent resin layer 4 is formed) of the single-sided protective polarizing film 3. Therefore, the affinity of the polarizer 1 surface (the surface where the transparent resin layer 4 is formed) of the aforementioned single-sided protective polarizing film 3 and the water-based coating liquid will increase, and the water-based coating liquid will affect the polarizer 1 of the aforementioned single-sided protective polarizing film 3 The wettability of the surface (the surface where the transparent resin layer 4 is formed) is improved. In addition, the aforementioned corona treatment or plasma treatment can also suppress the deviation value of the water contact angle on the surface of the polarizer 1 (the surface where the transparent resin layer 4 is formed).

In the manufacturing method of the present invention, it is advisable to carry out the aforementioned various treatments alone or in combination before the aforementioned step (2). In the case of combining, for example, the following method can be mentioned: (Combination 1) A surface protective film is attached to the polarizer 1 side of the single-sided protective polarizing film 3, and then the surface protective film is protected from the single-sided polarizing film 3 Peel off, and then apply activation treatment to the peeling surface of the single-sided protective polarizing film 3; or (combination 2) apply activation treatment to the polarizer 1 side of the single-sided protective polarizing film 3, then A method of attaching a surface protective film to the activated surface of the single-sided protective polarizing film 3, and then peeling the surface protective film from the single-sided protective polarizing film 3, etc.

2. Manufacturing method of polarizing film with adhesive layer The method of manufacturing polarizing film with adhesive layer of the present invention is characterized by the following steps: protecting the polarized light on one side of the transparent resin layer obtained by any of the foregoing manufacturing methods On the transparent resin layer of the film, an adhesive layer is formed.

As shown in FIG. 2, the polarizing film 11 with an adhesive layer obtained by the manufacturing method of the present invention is characterized in that it is further provided with an adhesive on the transparent resin layer 4 of the single-sided protective polarizing film 10 with a transparent resin layer. Layer 5.

(1) Adhesive layer A suitable adhesive can be used for the formation of the adhesive layer, and there is no particular restriction on the type. 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.

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 exhibiting such characteristics, it is better to use an acrylic adhesive.

The method of forming the adhesive layer can be produced by, for example, the following method: coating the aforementioned adhesive on a separation member that has been peeled off, drying and removing the polymerization solvent, etc. to form the adhesive layer, and then transferring The method of applying the adhesive to the transparent resin layer 4; or the method of forming the adhesive layer on the transparent resin layer 4 by coating the aforementioned adhesive on the transparent resin layer 4, drying and removing the polymerization solvent, etc. In addition, when applying the adhesive, one or more solvents other than the polymerization solvent may be appropriately added.

It is advisable to use a silicone release liner as a separation part after peeling treatment. In the step of coating and drying the adhesive on such a lining material to form an adhesive layer, a suitable and appropriate method can be used as a method for drying the adhesive according to the purpose. It is preferable to use a method of heating and drying the above-mentioned coated film. The heating and drying temperature is preferably 40°C to 200°C, preferably 50°C to 180°C, more preferably 70°C to 170°C. By setting the heating temperature to the above range, an adhesive with excellent adhesive properties can be obtained.

Suitable drying time can be adopted. The above-mentioned drying time is preferably 5 seconds to 20 minutes, preferably 5 seconds to 10 minutes, and more 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 a mold coater, etc.

The thickness of the adhesive layer is not particularly limited. For example, it is about 1 to 100 μm, 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.

Examples of constituent materials of the separator include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films; porous materials such as paper, cloth, and non-woven fabrics; meshes and foamed sheets Appropriate sheet materials such as, metal foil, and laminates thereof, etc., but in terms of excellent surface smoothness, plastic film is suitable.

The plastic film is not particularly limited as long as it is a film that can protect the aforementioned adhesive layer. Examples include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, and polymethylpentene film. Vinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, etc.

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

(2) Surface protection film A surface protection film can be provided on the polarizing film of the present invention (including a single-sided protection polarizing film with a transparent resin layer and a polarizing film with an adhesive layer). The surface protection film may be as described above.

3. The manufacturing method of the image display device The manufacturing method of the image display device of the present invention is characterized in that it uses the single-sided protective polarizing film with a transparent resin layer obtained by the foregoing manufacturing method, or the adhesive obtained by the foregoing manufacturing method The polarizing film of the agent layer is used to form an image display device.

The single-sided protective polarizing film with a transparent resin layer or the polarizing film with an adhesive layer obtained by the manufacturing method of the present invention can be used alone or laminated with an optical member to form an optical laminate to form a liquid crystal display device ( LCD), organic EL display device and other image display devices.

The aforementioned optical member is not particularly limited, and one layer or two or more layers such as reflective plates or semi-transmissive plates, retardation plates (including 1/2 and 1/4 wavelength plates), viewing angle compensation films, etc. can be used to form Optical structure of liquid crystal display devices, etc. As an optical laminate, particularly preferred is a reflective polarizing film formed by further laminating a reflective plate or a semi-transmissive reflective plate on the single-sided protective polarizing film with a transparent resin layer or the polarizing film with an adhesive layer of the present invention. The semi-transmissive polarizing film is an elliptical polarizing film or a circular polarizing film formed by laminating a phase difference plate on a single-sided protective polarizing film with a transparent resin layer or a polarizing film with an adhesive layer of the present invention. A wide viewing angle polarizing film formed by further laminating a viewing angle compensation film on a single-sided protective polarizing film of a resin layer or a polarizing film with an adhesive layer, or a single-sided protective polarizing film with a transparent resin layer of the present invention or an adhesive A polarizing film formed by further laminating a brightness enhancement film on the layered polarizing film.

The optical laminate in which the above-mentioned optical member is laminated on the single-sided protective polarizing film with a transparent resin layer or the polarizing film with an adhesive layer obtained by the manufacturing method of the present invention can be used in the manufacturing process of liquid crystal display devices. They are formed in separate layers, but those that are pre-laminated into optical films have advantages in terms of quality stability and assembly operations, and have the advantage of improving the manufacturing process of liquid crystal display devices. When two or more layers of optical members are laminated, an appropriate bonding means such as an adhesive layer can be used. When the aforementioned single-sided protective polarizing film with a transparent resin layer or a polarizing film with an adhesive layer is adhered, the optical axis of the polarizing film can be set to an appropriate arrangement angle in accordance with the target retardation characteristics and the like.

The single-sided protective polarizing film with a transparent resin layer or the polarizing film with an adhesive layer, or an optical laminate obtained by the manufacturing method of the present invention can be suitably used in the formation of various devices such as liquid crystal display devices. The manufacturing method of the liquid crystal display device can be carried out according to the conventional technology. That is, the liquid crystal display device is generally formed by appropriately assembling the liquid crystal cell, the polarizing film or the optical film, and the component parts such as the lighting system according to the demand, and installing the driving circuit. In the present invention, in addition to the use of the transparent resin of the present invention There are no special restrictions on the single-sided protective polarizing film or the polarizing film with the adhesive layer, or the optical laminate, except for this point, and it may be based on the conventional technology. For the liquid crystal cell, any type such as IPS type and VA type can be used, but the IPS type is particularly suitable.

A suitable liquid crystal display device can be formed as follows: a single-sided protective polarizing film with a transparent resin layer obtained by the manufacturing method of the present invention or a polarizing film with an adhesive layer or an optical laminate are arranged on one or both sides of the liquid crystal cell The liquid crystal display device; the lighting system uses a suitable liquid crystal display device such as a backlight or a reflector. In this case, the single-sided protective polarizing film with a transparent resin layer or the polarizing film with an adhesive layer or an optical laminate obtained by the manufacturing method of the present invention can be installed on one side or both sides of the liquid crystal cell. When the one-sided protective polarizing film with a transparent resin layer of the present invention or the polarizing film with an adhesive layer or an optical laminate are provided on both sides, they may be the same or different. In addition, when forming a liquid crystal display device, suitable parts such as diffuser, anti-glare layer, anti-reflection film, protective plate, ridge array, lens array sheet, light diffuser, backlight, etc. can be arranged in an appropriate position. Or more than 2 layers.

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

Production Example 1 (Production of Polarizer) Amorphous isophthalic acid-co-polyethylene terephthalate (IPA-co- PET) film with a water absorption rate of 0.75% and a glass transition temperature (Tg) of 75°C (Thickness: 100μm) One side of the substrate is corona treated, and the corona treated surface is coated at 25°C and contains polyvinyl alcohol in a ratio of 9:1 (degree of polymerization: 4200 / degree of saponification: 99.2 mol%) and acetyl acetyl modified PVA (trade name: Gohsefimer Z200 / degree of polymerization: 1200 / acetyl acetyl modified degree: 4.6% / saponification degree: 99.0 mol% or more / Japan Synthetic Chemicals An aqueous solution made by Industrial Co., Ltd. was dried to form a PVA-based resin layer with a thickness of 11 μm 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 with a liquid temperature of 30°C, the iodine concentration and immersion time were adjusted so that the polarizing plate had a desired 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 speed Uniaxial stretching is carried out between the cylinders so that the total stretching magnification in the longitudinal direction (longitudinal) reaches 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 Example 2 (Production of Polarizer) A 30 μm thick polyvinyl alcohol film with an average degree of polymerization of 2400 and a degree of saponification of 99.9 mol% was immersed in warm water at 30° C. for 60 seconds to swell. Next, it was immersed in a 0.3% aqueous solution of iodine/potassium iodide (weight ratio=0.5/8), and the film was dyed while extending it to 3.5 times. Then the stretching is carried out in an aqueous solution of borate at 65°C to make the total stretching ratio up to 6 times. After stretching, it was dried in an oven at 40° C. for 3 minutes to obtain a PVA-based polarizer. The thickness of the obtained polarizer was 12 μm.

Production Example 3 (Production of a single-sided protective polarizing film) As a protective film, a (meth)acrylic resin film with a thickness of 40 μm and a lactone ring structure that has been corona-treated on the easy-to-adhesive surface was used.

40 parts by weight of N-Hydroxyethyl acrylamide (HEAA), 60 parts by weight of acrylophrine (ACMO), and 3 parts by weight of photoinitiator (trade name: IRGACURE　819, manufactured by BASF) were blended to prepare UV-curing adhesive. Use it as an adhesive for protective films.

On the surface of the polarizer of the optical film laminate obtained in Production Example 1, the above-mentioned ultraviolet curable adhesive was applied so that the thickness of the adhesive layer after curing became 1 μm, and the above-mentioned protective film was laminated, and then irradiated as The ultraviolet rays of the active energy rays 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: 1600mW/cm2, 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. The non-crystalline IPA copolymer PET film substrate did not peel off but remained intact. The total thickness of the single-sided protective polarizing film (not including the amorphous IPA copolymer PET film substrate) using the thin polarizer is 46 μm. The optical properties of the obtained single-sided protective polarizing film were 42.8% monomer transmittance and 99.99% polarization degree.

<Monomer transmittance T and polarization degree P> Use a spectroscopic transmittance measuring device with integrating sphere (Dot-3c of Murakami Color Technology Research Institute Co., Ltd.) to measure the monomer transmittance of the obtained single-sided protective polarizing film Rate T and degree of polarization P. In addition, the degree of polarization P is based on the transmittance (parallel transmittance: Tp) when two identical polarizing films are overlapped with their transmission axes in parallel, and the transmission axes of the two are positive. The transmittance in the case of overlapping (orthogonal transmittance: Tc) is obtained by applying the following formula. Polarization degree P(%)={(Tp-Tc)/(Tp＋Tc)} 1/2×100 The transmittance is to set the fully polarized light obtained through the Glan-Taylor polarizer to 100%, and to borrow As shown by the Y value for visual sensitivity compensation of 2 degrees viewing angle (C light source) of JIS Z8701.

Production Example 4 (Production of coating liquid for forming transparent resin layer) A polyvinyl alcohol resin with a degree of polymerization of 2500 and a degree of saponification of 99.7 mol% was dissolved in pure water to prepare a solid content of 4% by weight and a viscosity of 60 mPa.s (25 °C) aqueous solution (coating liquid).

<Viscosity measurement> The viscosity of the coating liquid was measured under the following conditions using a VISCOMETER R85 viscometer "RE85L (manufactured by Toki Sangyo Co., Ltd.). Measuring temperature: 25°C Rotation number: 0.5~100rpm Cone rotor: 1°34'×R24

Example 1 (Production of single-sided protective polarizing film with transparent resin layer) The single-sided protective polarizing film obtained from Manufacturing Example 3 was peeled off from the amorphous IPA copolymer PET film substrate, and the surface was laminated on the stripped polarizer Protective film (trade name: TORETEC 7832C #30, manufactured by Toray Process Film Co., Ltd.). After leaving for 24 hours in this state, peel off the surface protection film, and use a gravure roll to apply the coating solution obtained in Manufacturing Example 4 (transparent resin layer forming material) on the surface of the polarizer (the surface of the polarizer without a protective film) , Its thickness is 25μm. After coating, use a floating oven to dry with hot air at 95°C for 30 seconds to form a transparent resin layer with a thickness of 1 μm, and produce a single-sided protective polarizing film with a transparent resin layer.

Example 2 In Example 1, after peeling off the amorphous IPA copolymer PET film substrate from the single-sided protective polarizing film obtained in Manufacturing Example 3, corona treatment was applied to the surface of the stripped polarizer (discharge amount: 0.038W· min/m ² , output power: 2.0kW, processing speed: 25m/min). Then, a surface protection film (trade name: TORETEC 7832C #30, manufactured by Toray Process Film Co., Ltd.) was attached. Except for the above, in the same manner as in Example 1, a single-sided protective polarizing film with a transparent resin layer was produced.

Example 3 In Example 1, after peeling off the surface protection film, corona treatment was applied to the stripped polarizer surface (discharge amount: 0.038W·min/m ² , output power: 2.0kW, processing speed: 25m /min). Then, a surface protection film (trade name: TORETEC 7832C #30, manufactured by Toray Process Film Co., Ltd.) was attached. Then peel off the surface protective film, and apply plasma treatment to the surface of the polarizer (the surface of the polarizer without protective film) (discharge capacity: 0.024W·min/m ² , output power: 1.0kW, processing speed: 20m /min), in the same manner as in Example 1, a single-sided protective polarizing film with a transparent resin layer was produced.

Example 4 In Example 1, the surface protective film was peeled off, and the surface of the polarizer (the surface of the polarizer without the protective film) was treated with plasma (discharge capacity: 0.024W·min/m ² , output power: 1.0kW, processing speed: 20m/min), in the same way as in Example 1, a single-sided protective polarizing film with a transparent resin layer was produced.

Comparative Example 1 In Example 1, after peeling off the amorphous IPA copolymer PET film substrate from the single-sided protective polarizing film obtained in Manufacturing Example 3, plasma treatment was applied to the surface of the stripped polarizer (discharge amount: 0.048W· min/m ² , output power: 2.0kW, processing speed: 20m/min), in the same way as in Example 1, a single-sided protective polarizing film with a transparent resin layer was produced.

Comparative Example 2 In Example 1, after peeling off the amorphous IPA copolymer PET film substrate from the single-sided protective polarizing film obtained in Production Example 3, the coating solution obtained in Production Example 4 was applied to the stripped polarizer surface ( Transparent resin layer forming material), except that, in the same manner as in Example 1, a single-sided protective polarizing film with a transparent resin layer was produced.

Reference Example 1 A single-sided protective polarizing film was produced in the same manner as in Production Example 3 except that the polarizer obtained in Production Example 2 was used. Except for using the aforementioned single-sided protective polarizing film, a single-sided protective polarizing film with a transparent resin layer was produced in the same manner as in Example 1.

Using the single-sided protective polarizing film with a transparent resin layer obtained in the Examples and Comparative Examples, the following evaluations were performed. The evaluation results are shown in Table 1.

<Water contact angle> The water contact angle of the transparent resin layer forming surface of the polarizer used in the Examples and Comparative Examples was measured using DM-501 manufactured by Kyowa Interface Chemical Co., Ltd., and the amount of applied liquid was set to 3 μL. The waiting time is set to 1000ms. In addition, the aforementioned water contact angle is measured at 25 points in the width direction of the polarizer and 5 points in the extension direction (conveying direction) in any number of positions on the polarizer, and the average water contact angle in the width direction and the water contact angle are evaluated. The deviation value of the contact angle. In addition, the water contact angle changes with the passage of time, so it is measured immediately after plasma treatment or corona treatment (specifically, within 5 minutes).

<Average film thickness> In the examples and comparative examples, the film thickness of the coating film formed by applying the water-based coating liquid (forming material of the transparent resin layer) is an optical beam splitter (USB2000+ manufactured by Ocean Optics Co., Ltd., light source: HL) -2000, fiber: ZFQ-12796 (200μm reflective fiber)) for measurement. The measurement conditions are as follows. The measurement is performed at 25 points in the width direction of the polarizer and 5 points in the extension direction (conveying direction), and the average value is obtained. (Measurement conditions) Measurement wavelength: 450nm~800nm Refractive index of transparent resin layer: 1.51

<Film thickness deviation value> Using an optical beam splitter (USB2000+ manufactured by Ocean Optics, light source: HL-2000, optical fiber: ZFQ-12796 (200μm reflective fiber)), the water-based coating liquid (transparent resin) was applied in the measurement examples and comparative examples The thickness deviation value of the coating film formed by the layer forming material). A sample with a size of 1200 mm×100 mm was measured at a pitch of 1 mm, and the film thickness deviation value was evaluated. Figure 3 (a), (b) and (c) show the surface of 100mm (the direction of the absorption axis, the longitudinal direction of the figure) × 100mm (the direction of the penetration axis, the transverse direction of the figure) for Examples 1, 3 and Comparative Example 1, respectively. Intima thickness deviation value result. (Measurement conditions) Measurement wavelength: 450nm~800nm Refractive index of transparent resin layer: 1.51

<Humidification environment test (visual confirmation of uneven appearance defects)> The single-sided protective polarizing film with a transparent resin layer obtained in the Examples and Comparative Examples was cut into 300mm (in the direction of the absorption axis) × 300mm (in the direction of the penetration axis) size. Two sheets of this single-sided protective polarizing film (sample) were prepared, and they were attached to both sides of the alkali-free glass so that the absorption axis thereof was orthogonal to each other to prepare a sample for humidified environment test. Put the resulting humidified environment test sample into a humidified environment (60°C/90%RH environment) for 300 hours. Then, the sample for the humidified environment test was placed on the backlight unit (uniform light emitting surface illumination, TWN series, manufactured by AITECHSYSTEM), and the visibility of uneven appearance defects was confirmed. Figures 4 (a), (b) and (c) are visually distinguishable photographs of Examples 1, 3 and Comparative Example 1 for observing uneven appearance defects. ○: Uneven appearance defects were not recognized visually. ×: A defect of uneven appearance is visually recognized.

Table 1

In Examples 1 to 4, the deviation value of the water contact angle of the transparent resin layer forming surface of the polarizer is the average water contact angle ±20°, and the deviation value of the water contact angle is low, so the thickness deviation value of the transparent resin layer obtained is low. The uneven appearance defect after the wet environment test is suppressed. On the other hand, in Comparative Examples 1 and 2, where the deviation of the water contact angle of the transparent resin layer forming surface of the polarizer was high, the thickness deviation of the obtained transparent resin layer was high, and the appearance unevenness defect occurred after the humidified environment test. Furthermore, in Reference Example 1, the thickness of the polarizer was 12 μm, so even if the deviation value of the water contact angle was high, the appearance unevenness defect was not visually recognized after the humidification environment test.

1‧‧‧Polarizer 2‧‧‧Protection film 3‧‧‧Single-sided protective polarizing film 4‧‧‧Transparent resin layer 5‧‧‧Adhesive layer 10‧‧‧Single-sided protective polarizing film with transparent resin layer 11 ‧‧‧Polarizing film with adhesive layer A‧‧‧Width direction of polarizing film

Fig. 1 is an example of a schematic cross-sectional view of a single-sided protective polarizing film with a transparent resin layer obtained by the manufacturing method of the present invention. 2 is an example of a schematic cross-sectional view of a polarizing film with an adhesive layer obtained by the manufacturing method of the present invention. Fig. 3 is a graph of the thickness deviation values of the transparent resin layer obtained in (a) Example 1, (b) Example 3, and (c) Comparative Example 1 measured using an interference optical film thickness meter. Fig. 4 is a photograph showing the visibility of the samples for humidification environment test obtained in (a) Example 1, (b) Example 3, and (c) Comparative Example 1 when observing uneven appearance defects.

1‧‧‧Polarizer

2‧‧‧Protection film

3‧‧‧Single-sided protective polarizing film

4‧‧‧Transparent resin layer

10‧‧‧Single-sided protective polarizing film with transparent resin layer

A‧‧‧Width direction of polarizing film

Claims (6)

A method for manufacturing a single-sided protective polarizing film with a transparent resin layer, characterized in that: the single-sided protective polarizing film with a transparent resin layer has a single-sided protective polarizing film with a protective film on only one side of the polarizer, and The transparent resin layer is provided on the surface of the polarizer of the aforementioned single-sided protective polarizing film, and the manufacturing method sequentially includes the following steps: Step (1), preparing a single-sided protective polarizing film with a protective film on only one side of the polarizer Step (2), coating the surface of the polarizer of the aforementioned single-sided protective polarizing film with an aqueous coating liquid containing resin components; and step (3), drying the resulting coating film to form a transparent resin layer; and, in the foregoing Before the step (2) of applying the water-based coating liquid, it further includes the following steps: applying activation treatment to the surface of the polarizing member of the single-sided protective polarizing film; and, in the activation of the single-sided protective polarizing film A surface protective film is attached to the treated surface, and then the surface protective film is peeled off from the single-sided protective polarizing film; wherein, the polarizer contains polyvinyl alcohol resin and has a thickness of 10 μm or less, and the polarizer is to be formed with a transparent resin layer The deviation of the water contact angle of the surface is within the range of the average water contact angle ±20°. For example, the method for manufacturing a single-sided protective polarizing film with a transparent resin layer of claim 1, wherein the aforementioned activation treatment is corona treatment and/ Or plasma treatment. Such as Claim 1 of the manufacturing method of a single-sided protective polarizing film with a transparent resin layer, wherein the deviation of the aforementioned water contact angle is within the range of the average water contact angle ±15°. The method for manufacturing a single-sided protective polarizing film with a transparent resin layer according to any one of claims 1 to 3, wherein the aforementioned average water contact angle is 90° or less. A method for manufacturing a polarizing film with an adhesive layer, characterized in that it has the following steps: a transparent resin layer with a single-sided protective polarizing film with a transparent resin layer obtained by the manufacturing method of any one of claims 1 to 4 On top, an adhesive layer is formed. A method of manufacturing an image display device, characterized in that it uses a single-sided protective polarizing film with a transparent resin layer obtained by the manufacturing method of any one of claims 1 to 4, or is obtained by the manufacturing method of claim 5 The polarizing film attached to the adhesive layer is formed.

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