KR102404504B1 - Method for manufacturing polarizing laminate film with protective film and method for manufacturing polarizing plate - Google Patents

Abstract

(Project) The manufacturing method of the light-polarizing laminated|multilayer film with a protection film which can provide the polarizing plate by which image distortion was suppressed when it used as a manufacture intermediate of a polarizing plate is provided.
(Solution) A step of forming a polyvinyl alcohol-based resin layer on at least one surface of the base film to obtain a laminated film, a step of stretching the laminated film to obtain a stretched laminated film, and the number of polyvinyl alcohol-based films of the stretched laminated film The process of obtaining a light-polarizing laminated film by dyeing a base layer with a dichroic dye to form a polarizer layer, The process of laminating|stacking a protection film on the surface at the side of the polarizer layer in a light-polarizing laminated film, and obtaining a light-polarizing laminated film with a protection film The protection film is provided with the manufacturing method of the light-polarizing laminated film with a protection film whose arithmetic mean roughness of the surface by the side of the polarizer layer is 0.150 micrometers or less.

Description

The manufacturing method of a light-polarizing laminated film with a protection film, and the manufacturing method of a polarizing plate TECHNICAL FIELD

This invention relates to the manufacturing method of the light-polarizing laminated film with a protection film, and the manufacturing method of a polarizing plate. Moreover, this invention relates to the light-polarizing laminated film with a protection film, and the light-polarizing laminated film roll with a protection film.

A polarizing plate is widely used for the image display apparatus etc. which make a liquid crystal display device a representative. As a polarizing plate, the thing of the structure which bonded thermoplastic resin films, such as a protective film, on the single side|surface or both surfaces of the polarizer layer which consists of polyvinyl alcohol-type resin is common. DESCRIPTION OF RELATED ART In recent years, thin film formation of a polarizing plate and by extension a polarizer layer is calculated|required with development to the mobile apparatus of an image display apparatus, a thin-screen television, etc.

As a manufacturing method of a polarizing plate provided with a thin-film polarizer layer, after extending|stretching the laminated|multilayer film which forms a polyvinyl alcohol-type resin layer by coating the coating liquid containing a polyvinyl alcohol-type resin on a base film, polyvinyl The alcohol-based resin layer is subjected to a dyeing treatment for adsorbing a dichroic dye to produce a light-polarizing laminated film in which a polarizer layer is formed on a base film, and then, an adhesive agent on the surface opposite to the base film in the polarizer layer After bonding thermoplastic resin films, such as a protective film, using is known, the method of peeling and removing a base film as needed (for example, patent document 1).

According to the above method, since the polyvinyl alcohol-based resin layer is formed by coating, it is easier to thin the polyvinyl alcohol-based resin layer as compared to thinning the single-layer (single) film made of the polyvinyl alcohol-based resin, Therefore, thinning of a polarizer layer also becomes easy. Moreover, since the polyvinyl alcohol-type resin layer and a polarizer layer of a thin film are always supported by any film during a manufacturing process, it is excellent also in the handleability of the film in a manufacturing process.

As the adhesive for bonding the thermoplastic resin film, an active energy ray-curable adhesive such as a water-based adhesive or an ultraviolet curable adhesive is known. Since it is difficult to volatilize and remove water|moisture content, many active energy ray-curable adhesive agents are used (for example, patent documents 2-5).

Patent Document 1: Japanese Patent Laid-Open No. 2000-338329 Patent Document 2: Japanese Patent Application Laid-Open No. 2013-205741 Patent Document 3: Japanese Patent Application Laid-Open No. 2012-203205 Patent Document 4: Japanese Patent Application Laid-Open No. 2012-203108 Patent Document 5: Japanese Patent Application Laid-Open No. 2004-245925

When a polarizing plate in which a thermoplastic resin film is bonded on a polarizer layer using an active energy ray-curable adhesive is observed under a fluorescent lamp from the thermoplastic resin film side, the image of the fluorescent lamp projected on the surface of the thermoplastic resin film may be distorted. Hereinafter, in this specification, such a phenomenon in which a reflected image is distorted is called "image distortion". This phase distortion is not only undesirable in appearance of a polarizing plate, but when a polarizing plate is introduce|transduced into an image display apparatus, there exists a possibility that a display may have a bad influence on the visibility of a display apparatus, such as distortion.

The objective of this invention is providing the optical laminated body (light-polarizing laminated film with a protection film) which can provide the polarizing plate by which the said image distortion was suppressed, when it uses as a manufacturing intermediate of a polarizing plate, and its manufacturing method. Another object of the present invention is to provide a polarizing plate in which the image distortion is suppressed and a method for manufacturing the same.

This invention provides the manufacturing method of the light-polarizing laminated film with a protection film shown below, the manufacturing method of a polarizing plate, the light-polarizing laminated film with a protection film, and the light-polarizing laminated film roll with a protection film.

[1] A step of forming a polyvinyl alcohol-based resin layer on at least one surface of the base film to obtain a laminated film;

a step of stretching the laminated film to obtain a stretched laminated film;

A step of obtaining a light-polarizing laminated film by dyeing the polyvinyl alcohol-based resin layer of the stretched laminated film with a dichroic dye to form a polarizer layer;

The process of laminating|stacking a protection film on the surface by the side of the said polarizer layer in the said light-polarizing laminated film, and obtaining the light-polarizing laminated film with a protection film

including,

The said protection film is the manufacturing method of the light-polarizing laminated film with a protection film whose arithmetic mean roughness of the surface by the side of the polarizer layer is 0.150 micrometers or less.

[2] The manufacturing method according to [1], wherein the protection film is laminated in contact with the surface of the polarizer layer.

[3] The manufacturing method according to [1] or [2], further comprising the step of winding the light-polarizing laminated film with a protection film to obtain a light-polarizing laminated film roll with a protection film.

[4] The process of obtaining a light-polarizing laminated film with a protection film by the manufacturing method as described in [1] or [2];

The process of peeling the said protection film from the said light-polarizing laminated|multilayer film with a protection film;

A step of laminating a first thermoplastic resin film through a layer of an active energy ray-curable adhesive on a surface of the light-polarizing laminated film on the side of the polarizer layer exposed by the step of peeling the protection film;

A step of curing the layer of the active energy ray-curable adhesive

A method of manufacturing a polarizing plate, comprising a.

[5] Between the process of obtaining the light-polarizing laminated film with a protection film and the process of peeling the said protection film, the process of winding up the said light-polarizing laminated film with a protection film to obtain a light-polarizing laminated film roll with a protection film, further including,

The manufacturing method as described in [4] which peels the said protection film from the light-polarizing laminated film with a protection film unwound from the said light-polarizing laminated film roll with a protection film in the process of peeling the said protection film.

[6] The production method according to [4] or [5], further comprising a step of peeling the base film after the step of curing the layer of the active energy ray-curable adhesive.

[7] A base film, a polarizer layer comprising a polyvinyl alcohol-based resin, and a protection film in this order,

The said protection film is the light-polarizing laminated film with a protection film whose arithmetic mean roughness of the surface by the side of the polarizer layer is 0.150 micrometers or less.

[8] The light-polarizing laminated film with a protection film according to [7], wherein the protection film is in contact with the surface of the polarizer layer.

[9] The light-polarizing laminated film roll with a protection film which is a wound product of the light-polarizing laminated film with a protection film as described in [7] or [8].

When used as a manufacturing intermediate of a polarizing plate, the optical laminated body (polarizing laminated film with a protection film) which can provide the polarizing plate by which image distortion was suppressed, its roll, and these manufacturing methods can be provided. In addition, it is possible to provide a polarizing plate in which image distortion is suppressed and a method for manufacturing the same.

BRIEF DESCRIPTION OF THE DRAWINGS It is a flowchart which shows the manufacturing method of the light-polarizing laminated film with a protection film which concerns on one Embodiment of this invention.
It is a schematic sectional drawing which shows an example of the laminated constitution of the laminated|multilayer film obtained by the resin layer formation process.
It is a schematic sectional drawing which shows an example of the laminated constitution of the stretched laminated|multilayer film obtained by an extending process.
It is a schematic sectional drawing which shows an example of the laminated constitution of the light-polarizing laminated film obtained at a dyeing process.
It is a schematic sectional drawing which shows an example of the laminated constitution of the light-polarizing laminated film with a protection film obtained by the protection film lamination process.
It is a flowchart which shows the manufacturing method of the polarizing plate which concerns on one Embodiment of this invention.
7 : is a schematic sectional drawing which shows an example of the laminated constitution of the film obtained by the protection film peeling process.
It is a schematic sectional drawing which shows an example of the layer structure of the 1st polarizing plate obtained through a 1st bonding process and a hardening process.
It is a schematic sectional drawing which shows an example of the layer structure of the 2nd polarizing plate obtained by the base film peeling process.
10 : is a schematic sectional drawing which shows an example of the layer structure of a 3rd polarizing plate.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment is disclosed and this invention is demonstrated in detail.

<The manufacturing method of the light-polarizing laminated film with a protection film>

BRIEF DESCRIPTION OF THE DRAWINGS It is a flowchart which shows the manufacturing method of the light-polarizing laminated film with a protection film which concerns on one Embodiment of this invention. As shown in FIG. 1, the manufacturing method of the light-polarizing laminated film with a protection film which concerns on one Embodiment of this invention is the following process:

A resin layer forming step (S10) of forming a polyvinyl alcohol-based resin layer on at least one surface of the base film to obtain a laminated film;

Stretching step (S20) of stretching a laminated film to obtain a stretched laminated film;

Dyeing step (S30) of obtaining a light-polarizing laminated film by dyeing the polyvinyl alcohol-based resin layer of the stretched laminated film with a dichroic dye to form a polarizer layer;

Protection film lamination process (S40) which laminates|stacks a protection film on the surface by the side of the polarizer layer in a light-polarizing laminated film, and obtains a light-polarizing laminated film with a protection film (S40)

includes

The manufacturing method of the light-polarizing laminated film with a protection film may further include a winding process of winding up the light-polarizing laminated film with a protection film after the protection film lamination process (S40) to obtain a light-polarizing laminated film roll with a protection film. . The light-polarizing laminated film with a protection film and the light-polarizing laminated film roll with a protection film can be used as a manufacturing intermediate for manufacturing a polarizing plate so that it may mention later.

As used herein, the term "polarizing laminated film" is a film comprising a base film and a polarizer layer laminated thereon, and does not contain a thermoplastic resin film such as a protective film laminated (bonded) to the polarizer layer through an adhesive layer. say film. What laminated|stacked the protection film on the surface by the side of the polarizer layer of the light-polarizing laminated film is called "light-polarizing laminated film with a protection film" in this specification. In addition, in this specification, a "polarizing plate" means a film containing a polarizer layer and thermoplastic resin films, such as a protective film laminated|stacked (bonded together) on at least one surface of a polarizer layer through an adhesive bond layer. The polarizing plate may contain the said base film. Moreover, a polarizing plate is laminated|stacked (bonded) on the other surface with 1st thermoplastic resin films, such as a polarizer layer, a protective film laminated|stacked (bonded) through an adhesive bond layer on the at least one surface, and an adhesive bond layer or an adhesive layer on the other side. You may include 2nd thermoplastic resin films, such as a protective film to be used.

Thermoplastic resin films, such as a protective film laminated|stacked (bonded together) to a polarizer layer through an adhesive bond layer, are an optical film normally. An optical film means the film which is a member introduce|transduced into optical devices, such as a display apparatus, or its part. A base film is a film comprised from, for example, a thermoplastic resin, and is not normally introduce|transduced into optical devices, such as a display apparatus, but it is common to peel and remove before the said introduction. Therefore, the base film, Preferably peeling from a polarizer layer is possible. However, it is not excluded that the base film may be an optical film.

Hereinafter, each process mentioned above is demonstrated, referring drawings.

[1] Resin layer forming step (S10)

With reference to FIG. 2, this process is a process of forming the polyvinyl alcohol-type resin layer 6 on at least one surface of the base film 30, and obtaining the laminated|multilayer film 100. This polyvinyl alcohol-type resin layer 6 is a layer used as the polarizer layer 5 (FIG. 4) through extending|stretching and dyeing. The polyvinyl alcohol-type resin layer 6 can be formed by coating the coating liquid containing a polyvinyl alcohol-type resin on one side or both surfaces of the base film 30, and drying it. The method of forming the polyvinyl alcohol-type resin layer 6 by such coating is advantageous in that it is easy to obtain the polarizer layer 5 of a thin film, for example. The resin layer formation process (S10) is continuously performed, for example, continuously unwinding the base film 30 from the film roll which is a winding object of the elongate base film 30, and conveying this. Film conveyance can be performed using a guide roll etc.

(base film)

The base film 30 may be composed of a thermoplastic resin, and among them, it is preferable to be composed of a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, stretchability, and the like. Specific examples of such a thermoplastic resin include, for example, polyolefin-based resins such as chain polyolefin-based resins and cyclic polyolefin-based resins (norbornene-based resins, etc.); polyester-based resin; (meth)acrylic resin; Cellulose ester-based resins such as cellulose triacetate and cellulose diacetate; polycarbonate-based resin; polyvinyl alcohol-based resin; polyvinyl acetate-based resin; polyarylate-based resin; polystyrene-based resin; polyether sulfone-based resin; polysulfone-based resin; polyamide-based resin; polyimide-based resin; and mixtures, copolymers and the like thereof.

In this specification, "(meth)acryl" means at least one chosen from acryl and methacryl. The same applies when referring to "(meth)acryloyl" or the like.

The base film 30 may have a single-layer structure composed of one resin layer composed of one or two or more types of thermoplastic resins, or a multilayer structure in which a plurality of resin layers composed of one type or two or more types of thermoplastic resins are laminated. The base film 30 is made of a resin that can be stretched at a stretching temperature suitable for stretching the polyvinyl alcohol-based resin layer 6 when stretching the laminated film 100 in the stretching step (S20) to be described later. It is preferable to be

Examples of the chain polyolefin resin include homopolymers of chain olefins such as polyethylene resin and polypropylene resin, and copolymers composed of two or more kinds of chain olefins. The base film 30 which consists of a chain|strand-type polyolefin resin is preferable at the point which is easy to extend|stretch stably at a high magnification. Among them, the base film 30 is a polypropylene resin (polypropylene resin, which is a homopolymer of propylene, or a copolymer mainly composed of propylene), a polyethylene resin (polyethylene resin which is a homopolymer of ethylene, or ethylene as a main component) It is more preferable that it consists of a copolymer) or the like.

The copolymer mainly comprising propylene, which is one of the examples suitably used as the thermoplastic resin constituting the base film 30 , is a copolymer of propylene and another monomer copolymerizable therewith.

Examples of the other monomer copolymerizable with propylene include ethylene and α-olefin. As the α-olefin, an α-olefin having 4 or more carbon atoms is preferably used, and more preferably an α-olefin having 4 to 10 carbon atoms. Specific examples of the ?-olefin having 4 to 10 carbon atoms include, for example, linear monoolefins such as 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and 1-decene; branched monoolefins such as 3-methyl-1-butene, 3-methyl-1-pentene, and 4-methyl-1-pentene; vinylcyclohexane; and the like. A random copolymer may be sufficient as the copolymer of propylene and the other monomer copolymerizable with this, and a block copolymer may be sufficient as it.

Content of the said other monomer is 0.1 to 20 weight% in a copolymer, Preferably it is 0.5 to 10 weight%. Content of the other monomer in a copolymer can be calculated|required by performing infrared (IR) spectrum measurement according to the method described on page 616 of "Polymer Analysis Handbook" (1995, published by Kinokuniya Bookstore).

Among the above, as the polypropylene resin, a propylene homopolymer, a propylene-ethylene random copolymer, a propylene-1-butene random copolymer, or a propylene-ethylene-1-butene random copolymer is preferably used.

It is preferable that the stereoregularity of a polypropylene resin is substantially isotactic or syndiotactic. The base film 30 made of a polypropylene-based resin having substantially isotactic or syndiotactic stereoregularity has relatively good handling properties and excellent mechanical strength in a high-temperature environment.

Cyclic polyolefin-based resin is a generic term for resins polymerized using cyclic olefin as a polymerization unit, for example, Japanese Patent Application Laid-Open No. Hei 1-240517, Japanese Patent Application Laid-Open No. 3-14882, and Japanese Patent Application Laid-Open No. Hei 3 -122137, etc. are mentioned resin. Specific examples of the cyclic polyolefin resin include a ring-opened (co)polymer of a cyclic olefin, an addition polymer of a cyclic olefin, and a copolymer of a cyclic olefin and a chain olefin such as ethylene and propylene (typically random air) coalescing), graft polymers modified with unsaturated carboxylic acids or derivatives thereof, and hydrides thereof. Among them, a norbornene-based resin using a norbornene-based monomer such as norbornene or a polycyclic norbornene-based monomer as the cyclic olefin is preferably used.

Polyester-type resin is resin which has an ester bond except the following cellulose-ester-type resin, Comprising: It is common to consist of polycondensate of polyhydric carboxylic acid or its derivative(s), and polyhydric alcohol. As the polyhydric carboxylic acid or its derivative, divalent dicarboxylic acid or its derivative can be used, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalenedicarboxylic acid. As the polyhydric alcohol, divalent diol can be used, and examples thereof include ethylene glycol, propanediol, butanediol, neopentyl glycol, and cyclohexanedimethanol.

A representative example of the polyester-based resin is polyethylene terephthalate, which is a polycondensate of terephthalic acid and ethylene glycol. Although polyethylene terephthalate is crystalline resin, the thing of the state before a crystallization process is easy to perform a process, such as extending|stretching. If necessary, crystallization treatment may be performed during or after stretching by heat treatment or the like. Moreover, the copolymerized polyester which lowered the crystallinity (or made it amorphous) by copolymerizing another type of monomer with the skeleton of a polyethylene terephthalate is also used suitably. As an example of such a resin, what copolymerized cyclohexane dimethanol or isophthalic acid is mentioned, for example. Since these resins are also excellent in ductility, they can be used suitably.

Specific examples of polyester resins other than polyethylene terephthalate and copolymers thereof are given, for example, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclo Hexane dimethyl terephthalate and polycyclohexane dimethyl naphthalate.

(meth)acrylic-type resin is resin which uses the compound which has a (meth)acryloyl group as a main structural monomer. Specific examples of the (meth)acrylic resin include, for example, poly(meth)acrylic acid esters such as polymethyl methacrylate; methyl methacrylate-(meth)acrylic acid copolymer; methyl methacrylate-(meth)acrylic acid ester copolymer; methyl methacrylate-acrylic acid ester-(meth)acrylic acid copolymer; (meth)methyl acrylate-styrene copolymer (MS resin, etc.); copolymers of methyl methacrylate and a compound having an alicyclic hydrocarbon group (eg, methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate-(meth) acrylate norbornyl copolymer, etc.) . Preferably, a polymer containing poly(meth)acrylic acid C _1-6 alkylester as a main component, such as poly(meth)methyl acrylate, is used, and more preferably, methyl methacrylate as a main component (50 to 100% by weight, Preferably 70 to 100% by weight) of a methyl methacrylate-based resin is used.

Cellulose ester-type resin is ester of a cellulose and a fatty acid. Specific examples of the cellulose ester-based resin include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. Moreover, these copolymers and the thing by which a part of hydroxyl group was modified by other substituents are mentioned. Among these, cellulose triacetate (triacetyl cellulose) is especially preferable.

The polycarbonate-based resin is an engineering plastic composed of a polymer to which a monomer unit is bonded through a carbonate group, and is a resin having high impact resistance, heat resistance, flame retardancy, and transparency. The polycarbonate-based resin constituting the base film 30 may be a resin called a modified polycarbonate in which a polymer skeleton is modified to lower the photoelastic coefficient, or a copolymerized polycarbonate having improved wavelength dependence.

Among the above, one of the thermoplastic resins preferably used is a polypropylene resin from the viewpoints of stretchability and heat resistance.

The base film 30 may include any appropriate additives in addition to the above-described thermoplastic resin. As an additive, a ultraviolet absorber, antioxidant, a lubricant, a plasticizer, a mold release agent, a coloring inhibitor, a flame retardant, a nucleating agent, antistatic agent, a pigment, a coloring agent, etc. are mentioned, for example. Content of the thermoplastic resin in the base film 30 becomes like this. Preferably it is 50 to 100 weight%, More preferably, it is 50 to 99 weight%, More preferably, it is 60 to 98 weight%, Most preferably, it is 70 to 97 weight%. to be.

The thickness of the base film 30 is usually 1-500 µm in terms of strength and handleability, preferably 1-300 µm, more preferably 5-200 µm, still more preferably 5-150 µm. .

(Formation of polyvinyl alcohol-based resin layer)

The coating liquid to be coated on the base film 30 is preferably a polyvinyl alcohol-based resin solution obtained by dissolving a polyvinyl alcohol-based resin powder in a good solvent (eg, water). The coating liquid may contain additives, such as a plasticizer and surfactant, as needed. As polyvinyl alcohol-type resin, what saponified polyvinyl acetate-type resin can be used. As polyvinyl acetate-type resin, the copolymer of vinyl acetate and other monomer copolymerizable to this other than polyvinyl acetate which is a homopolymer of vinyl acetate is illustrated. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth)acrylamides having an ammonium group.

The degree of saponification of the polyvinyl alcohol-based resin may be in the range of 80.0 to 100.0 mol%, preferably in the range of 90.0 to 99.5 mol%, and more preferably in the range of 94.0 to 99.0 mol%. The water resistance and heat-and-moisture resistance of a light-polarizing laminated film, a light-polarizing laminated film with a protection film, and a polarizing plate as a saponification degree is less than 80.0 mol% may fall. When a polyvinyl alcohol-type resin with a saponification degree exceeding 99.5 mol% is used, the dyeing rate of a dichroic dye may become slow, productivity may fall, and the polarizer layer which has sufficient polarization performance may not be obtained.

The degree of saponification is the ratio of the acetic acid group (acetoxy group: -OCOCH ₃ ) contained in the polyvinyl acetate-based resin, which is a raw material of the polyvinyl alcohol-based resin, changed to a hydroxyl group by the saponification process, expressed as a unit ratio (mol%). , the formula:

Saponification degree (mol%) = 100 x (number of hydroxyl groups) ÷ (number of hydroxyl groups + number of acetate groups)

is defined as Saponification degree can be calculated|required based on JISK6726:1994.

The polyvinyl alcohol-based resin may be a modified polyvinyl alcohol partially modified. For example, the polyvinyl alcohol-based resin is olefins such as ethylene and propylene; unsaturated carboxylic acids such as (meth)acrylic acid and crotonic acid; What modified|denatured with the alkylester of unsaturated carboxylic acid, (meth)acrylamide, etc. is mentioned. It is preferable that it is less than 30 mol%, and, as for the ratio of modification|denaturation, it is more preferable that it is less than 10 %. When it modifies|denatures more than 30 mol%, it becomes difficult to adsorb|suck a dichroic dye, and there exists a tendency for the polarizer layer which has sufficient polarization|polarized-light performance to be hard to be obtained.

The average degree of polymerization of the polyvinyl alcohol-based resin is preferably 100 to 10000, more preferably 1500 to 8000, and still more preferably 2000 to 5000. The average degree of polymerization of polyvinyl alcohol-type resin can also be calculated|required based on JISK6726:1994.

A method of applying the coating solution to the base film 30 includes a wire bar coating method; roll coating methods such as reverse coating and gravure coating; die coat method; comma coat method; lip coat method; spin coating method; screen coating method; Fountain coating method; dipping method; It can select suitably from methods, such as a spray method.

The drying temperature and drying time of the coating layer (polyvinyl alcohol-based resin layer before drying) are set according to the kind of solvent contained in the coating solution. The drying temperature is, for example, 50 to 200°C, preferably 60 to 150°C. When the solvent contains water, the drying temperature is preferably 80°C or higher.

The polyvinyl alcohol-based resin layer 6 may be formed on only one surface of the base film 30 or may be formed on both surfaces. When formed on both sides, curling of the film that may occur during the manufacture of the light-polarizing laminated film 300 (see Fig. 4) can be suppressed, and two polarizing plates can be obtained from one light-polarizing laminated film 300 Therefore, it is advantageous also in terms of production efficiency of a polarizing plate.

The thickness of the polyvinyl alcohol-type resin layer 6 in the laminated|multilayer film 100 becomes like this. Preferably it is 3-30 micrometers, More preferably, it is 5-20 micrometers. In the case of the polyvinyl alcohol-based resin layer 6 having a thickness within this range, the dyeing property of the dichroic dye is good, the polarization performance is excellent, and it is sufficiently thin through the stretching step (S20) and the dyeing step (S30) described later. The polarizer layer 5 (for example, 10 micrometers or less in thickness) can be obtained.

Prior to the coating of the coating solution, in order to improve the adhesion between the base film 30 and the polyvinyl alcohol-based resin layer 6, at least the base film 30 on the side where the polyvinyl alcohol-based resin layer 6 is formed. You may give corona treatment, plasma treatment, flame (flame) treatment, etc. to the surface. For the same reason, the polyvinyl alcohol-based resin layer 6 may be formed on the base film 30 through a primer layer or the like. The primer layer may also serve to enable peeling of the base film 30 from the polarizer layer 5 .

A primer layer can be formed by drying, after coating the coating liquid for primer layer formation on the surface of the base film 30. This coating liquid contains a component which exhibits a strong adhesive force to a certain extent to both of the base film 30 and the polyvinyl alcohol-type resin layer 6, Usually, the resin component and solvent which provide this adhesive force are included. . As a resin component, Preferably, a thermoplastic resin excellent in transparency, thermal stability, ductility, etc. is used, For example, (meth)acrylic-type resin, polyvinyl alcohol-type resin, etc. are mentioned. Especially, polyvinyl alcohol-type resin which provides favorable adhesive force is used preferably. More preferably, it is polyvinyl alcohol resin. As the solvent, a general organic solvent or aqueous solvent capable of dissolving the resin component is usually used, but it is preferable to form the primer layer from a coating solution using water as a solvent.

In order to increase the intensity|strength of a primer layer, you may add a crosslinking agent to the coating liquid for primer layer formation. Specific examples of the crosslinking agent include epoxy-based, isocyanate-based, dialdehyde-based, metal-based (eg, metal salts, metal oxides, metal hydroxides, organometallic compounds), and polymer-based crosslinking agents. When a polyvinyl alcohol-based resin is used as the resin component for forming the primer layer, polyamide epoxy resin, methylolated melamine resin, dialdehyde-based cross-linking agent, metal chelate compound-based cross-linking agent, and the like are preferably used.

It is preferable that it is about 0.05-1 micrometer, and, as for the thickness of a primer layer, it is more preferable that it is 0.1-0.4 micrometer. If thickness is this range, the appropriate adhesive force between the base film 30 and the polyvinyl alcohol-type resin layer 6 will be easy to be acquired.

A method of applying the coating solution for forming the primer layer to the base film 30 may be the same as the coating solution for forming the polyvinyl alcohol-based resin layer. The drying temperature of the coating layer which consists of the coating liquid for primer layer formation is 50-200 degreeC, for example, Preferably it is 60-150 degreeC. When the solvent contains water, the drying temperature is preferably 80°C or higher.

[2] Stretching process (S20)

In this process with reference to FIG. 3 , the laminated film 100 is stretched to obtain a stretched laminated film 200 comprising the stretched base film 30 ′ and the stretched polyvinyl alcohol-based resin layer 6 ′. to be. Extending|stretching is uniaxial stretching normally. Extending process S20 can be performed continuously, conveying the elongate laminated|multilayer film 100, for example. Film conveyance can be performed using a guide roll etc.

Although the draw ratio of the laminated|multilayer film 100 can be suitably selected according to the desired polarization characteristic, Preferably, it is more than 5 times and 17 times or less with respect to the original length of the laminated|multilayer film 100, More preferably, it exceeds 5 times. less than 8 times. If the draw ratio is 5 times or less, the polyvinyl alcohol-based resin layer 6' is not sufficiently oriented, so that the polarization degree of the polarizer layer 5 may not be sufficiently high. On the other hand, when the draw ratio exceeds 17 times, breakage of the film tends to occur at the time of stretching, and the thickness of the stretched laminated film 200 becomes thinner than necessary, and there is a risk that workability and handleability in the post-process may be lowered. there is

An extending|stretching process is not limited to extending|stretching in one stage, You can also perform it in multiple stages. In this case, all of the multi-step stretching treatment may be performed continuously before the dyeing step (S30), and the stretching treatment after the second step may be performed simultaneously with the dyeing treatment and/or crosslinking treatment in the dyeing step (S30). good night. Thus, when performing an extending|stretching process in multiple stages, it is preferable to perform an extending|stretching process so that it may become a draw ratio of more than 5 times including the whole stage of an extending|stretching process.

The extending|stretching process may be longitudinal extending|stretching extended in the film longitudinal direction (film conveyance direction), and horizontal stretching or diagonal extending|stretching etc. extended in the film width direction may be sufficient. Examples of the longitudinal stretching method include inter-roll stretching using rolls (nip rolls, etc.), compression stretching, stretching using a chuck (clip), hot roll stretching using a hot roll, and the like. The tenter method etc. are mentioned. As the stretching treatment, either a wet stretching method or a dry stretching method can be adopted.

The stretching temperature is set above the temperature at which the polyvinyl alcohol-based resin layer 6 and the entire base film 30 exhibit fluidity to the extent that they can be stretched, preferably the phase transition temperature (melting point or glass transition) of the base film 30 . temperature) in the range of -30°C to +30°C, more preferably in the range of -30°C to +5°C, and still more preferably in the range of -25°C to +0°C. When the base film 30 consists of a plurality of resin layers, the phase transition temperature means the highest phase transition temperature among the phase transition temperatures indicated by the plurality of resin layers.

When the stretching temperature is lower than -30°C of the phase transition temperature, it is difficult to achieve high magnification stretching of more than 5 times, or the fluidity of the base film 30 is too low, which tends to make stretching treatment difficult. When extending|stretching temperature exceeds +30 degreeC of a phase transition temperature, there exists a tendency for extending|stretching to become difficult because the fluidity|liquidity of the base film 30 is too large. From the viewpoint of more easily achieving a high draw ratio of more than 5 times, the drawing temperature is within the above range, more preferably 120°C or higher.

As a heating method of the laminated|multilayer film 100 in an extending|stretching process, it is a zone heating method (For example, the method of heating in the same extending|stretching zone as the heating furnace adjusted to predetermined temperature by blowing hot air); In the case of stretching using a roll, a method of heating the roll itself; There is a heater heating method (a method in which an infrared heater, a halogen heater, a panel heater, etc. are installed above and below the laminated film 100 and heated by radiant heat) and the like. In the extending|stretching system between rolls, the zone heating method is preferable from a viewpoint of the uniformity of extending|stretching temperature.

Prior to extending|stretching process S20, you may provide the preheating process process of preheating laminated|multilayer film 100. As a preheating method, the method similar to the heating method in an extending|stretching process can be used. The preheating temperature is preferably in the range of -50°C to ±0°C of the stretching temperature, and more preferably in the range of -40°C to -10°C in the stretching temperature.

Moreover, you may provide a heat setting treatment process after the extending process in an extending process S20. The heat setting treatment is a treatment in which heat treatment is performed above the crystallization temperature of the polyvinyl alcohol-based resin while holding the edge portion of the stretched laminated film 200 in a tension state while gripping it with a clip. Crystallization of the polyvinyl alcohol-based resin layer 6' is promoted by this heat setting treatment. It is preferable that it is the range of -0 degreeC - -80 degreeC of extending|stretching temperature, and, as for the temperature of a heat setting process, it is more preferable that it is the range of -0 degreeC - -50 degreeC of extending|stretching temperature.

[3] Dyeing process (S30)

With reference to FIG. 4, this process is a process of dyeing the polyvinyl alcohol-type resin layer 6' of the stretched laminated|multilayer film 200 with a dichroic dye, making this adsorption-oriented, and setting it as the polarizer layer 5. Through this process, the light-polarizing laminated film 300 in which the polarizer layer 5 was laminated|stacked on one side or both surfaces of the base film 30' is obtained. The dyeing process (S30) can be performed continuously, conveying the elongate stretched laminated|multilayer film 200, for example. Film conveyance can be performed using a guide roll etc.

Specific examples of the dichroic dye include iodine or dichroic organic dye. Specific examples of the dichroic organic dye include, for example, Red BR, Red LR, Red R, Pink LB, Rubin BL, Bordeaux GS, Sky Blue LG, Lemon Yellow, Blue BR, Blue 2R, Navy RY, Green LG, Violet LB. , Violet B, Black H, Black B, Black GSP, Yellow 3G, Yellow R, Orange LR, Orange 3R, Scarlet GL, Scarlet KGL, Congo Red, Brilliant Violet BK, Supra Blue G, Supra Blue GL, Supra Orange GL, Includes Direct Sky Blue, Direct Fast Orange S, and Fast Black. A dichroic dye may be used individually by 1 type, and may use 2 or more types together.

The dyeing process (S30) can be performed by immersing the stretched laminated|multilayer film 200 in the liquid (dyeing bath) containing a dichroic dye. As a dyeing bath, the solution which melt|dissolved the said dichroic dye in the solvent can be used. As a solvent of a dyeing solution, although water is generally used, the organic solvent compatible with water may further be added. It is preferable that it is 0.01 to 10 weight%, and, as for the density|concentration of the dichroic dye in a dyeing bath, it is more preferable that it is 0.02 to 7 weight%.

When using an iodine as a dichroic dye, it is preferable to further add iodide to the dyeing bath containing an iodine from the point which can improve dyeing efficiency. Examples of the iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide. The density|concentration of the iodide in a dyeing bath becomes like this. Preferably it is 0.01 to 20 weight%. Among iodides, it is preferable to add potassium iodide. When potassium iodide is added, the ratio of iodine to potassium iodide is in a weight ratio, preferably 1:5 to 1:100, and more preferably 1:6 to 1:80. The temperature of a dyeing bath becomes like this. Preferably it is 10-60 degreeC, More preferably, it is 20-40 degreeC.

Moreover, you may perform further extending|stretching process with respect to the stretched laminated|multilayer film 200 during a dyeing|staining process (S30). As an embodiment in this case, 1) In the said extending process (S20), after performing an extending|stretching process at a magnification lower than the target, during the dyeing process in the dyeing process (S30), the total draw ratio is the target. As will be described later, when crosslinking treatment is performed after dyeing treatment, in the above stretching step (S20), stretching treatment is performed at a magnification lower than the target, and then dyeing step During the dyeing treatment in (S30), the stretching treatment is performed to the extent that the total draw ratio does not reach the target magnification, and then, the stretching treatment is performed during the crosslinking treatment so that the final total draw ratio becomes the target magnification. and the like.

It is preferable to perform the dyeing|staining process (S30) after performing the extending|stretching process to a certain extent with respect to the laminated|multilayer film 100 with respect to the laminated|multilayer film 100 so that the dichroic dye adsorbed to the polyvinyl alcohol-type resin layer can be orientated favorably.

The dyeing process (S30) may include the crosslinking process performed following the dyeing process. A crosslinking treatment process can be performed by immersing the stretched laminated|multilayer film after a dyeing process in the liquid (crosslinking bath) containing a crosslinking agent. Examples of the crosslinking agent include boric acid, boron compounds such as borax, glyoxal, glutaraldehyde, and the like. Only 1 type may be used for a crosslinking agent, and 2 or more types may be used together. As a crosslinking bath, the solution which melt|dissolved the crosslinking agent in the solvent can be used. Although water can be used as a solvent, you may further contain the organic solvent compatible with water. The concentration of the crosslinking agent in the crosslinking bath is preferably 1 to 20% by weight, more preferably 6 to 15% by weight.

The crosslinking bath may further include iodide. By addition of iodide, the polarization characteristic in the surface of the polarizer layer 5 can be made uniform more. Specific examples of iodide are the same as described above. The concentration of iodide in the crosslinking bath is preferably 0.05 to 15% by weight, and more preferably 0.5 to 8% by weight. The temperature of the crosslinking bath is preferably 10 to 90°C.

Moreover, a crosslinking process can also be performed simultaneously with a dyeing|staining process by mix|blending a crosslinking agent in a dyeing bath. Moreover, you may perform the process of immersing in a crosslinking bath twice or more using 2 or more types of crosslinking baths from which a composition differs. You may perform an extending|stretching process during a crosslinking process. The specific aspect which implements an extending|stretching process during a crosslinking process is as above-mentioned.

After the dyeing step (S30), a washing step and a drying step may be performed. A washing process usually includes a water washing process. A water washing process can be performed by immersing the film after a dyeing process or a crosslinking process in pure water, such as ion-exchange water and distilled water. Water washing temperature is 3-50 degreeC normally, Preferably it is 4-20 degreeC. The washing process may be a combination of a water washing process and a washing process using an iodide solution. As a drying process performed after a washing|cleaning process, arbitrary suitable methods, such as natural drying, air drying, and heat drying, are employable. For example, in the case of heat drying, the drying temperature is usually 20 to 95°C.

The thickness of the polarizer layer 5 which the light-polarizing laminated film 300 has becomes like this. Preferably it is 10 micrometers or less, More preferably, it is 8 micrometers or less, More preferably, it is 7 micrometers or less. A thin polarizing plate can be obtained by making the thickness of the polarizer layer 5 into 10 micrometers or less. The thickness of the polarizer layer 5 is usually 1 µm or more or 2 µm or more.

As described above, when a polarizing plate in which a thermoplastic resin film is bonded on a polarizer layer using an active energy ray-curable adhesive is observed under a fluorescent lamp from the thermoplastic resin film side, on the fluorescent lamp projected on the surface of the thermoplastic resin film, “image distortion” may occur. The image distortion is caused by the curing shrinkage of the adhesive layer accompanying rapid curing by irradiation with active energy ray or the distortion of the surface of the polarizer layer caused by the rapid application of heat from the active energy ray light source, the minute unevenness of the surface of the polarizer layer. It has been found to occur as a result of this emphasis. The emphasis of such minute unevenness|corrugation is easy to generate|occur|produce when the thickness of the polarizer layer 5 is small and rigidity is low. Therefore, the present invention capable of suppressing image distortion is particularly advantageous when the thickness of the polarizer layer 5 is small, for example, when the thickness of the polarizer layer 5 is 10 µm or less, furthermore, 8 µm or less.

[4] Protect film lamination process (S40)

With reference to FIG. 5, this process laminates|stacks the protection film 7 on the surface by the side of the polarizer layer 5 in the light-polarizing laminated film 300, The process of obtaining the light-polarizing laminated|multilayer film 400 with a protection film to be. It is preferable that the protection film 7 is laminated|stacked on the polarizer layer 5 in contact with the surface (surface on the opposite side to the base film 30') of the polarizer layer 5. When the polarizer layers 5 are laminated|stacked on both surfaces of the base film 30', the protection film 7 can be laminated|stacked on each polarizer layer 5. As shown in FIG.

The protection film lamination process S40 overlaps these films, for example, conveying the long light-polarizing laminated film 300 and the protection film 7, and passes the laminated body between a pair of rolls (pasting rolls) It includes the process of pressing by pushing. Film conveyance can be performed using a guide roll etc. The pressure (nip pressure) applied to the laminate by the bonding roll is, for example, 0.05 to 2 MPa, preferably 0.08 to 1 MPa.

As the protection film 7, the thing whose arithmetic mean roughness Ra of the surface by the polarizer layer 5 side is 0.150 micrometers or less is used. Using such a protection film 7 becomes advantageous in suppressing the image distortion which may arise in the polarizing plate formed by bonding a thermoplastic resin film together on the polarizer layer 5 using an active energy ray-curable adhesive agent.

For example, in the case of a manufacturing method in which the light-polarizing laminated film 300 is supplied to the polarizing plate manufacturing process as it is without laminating a protection film on the polarizer layer 5, the polarizer layer 5 is particularly prone to scratches, and the degree of breakage Since it is easy to become, when conveying the light-polarizing laminated film 300, the polarizer layer 5 is easily damaged or damaged. In addition, when a protection film is not laminated|stacked on the polarizer layer 5, it is difficult to wind up the light-polarizing laminated film 300 once and make it into a roll, and even if it can be set as a roll, a flaw occurs at the time of winding-up, and damage prone to occur

By laminating the protection film 7, it is possible to prevent or suppress scratches and breakage on the surface of the polarizer layer 5, and the light-polarizing laminated film 400 with a protection film can be wound up into a roll. . When it is set as a roll state, as a manufacturing intermediate for supplying to a polarizing plate manufacturing process, for example, the degree of freedom and efficiency of a polarizing plate manufacturing process can be improved, for example, once stored in a warehouse (or managed as stock). In this respect, it is advantageous to laminate the protection film 7 on the polarizer layer 5 .

However, when the protection film is laminated on the polarizer layer 5, the protection film is not laminated, and compared to the case where the polarizing laminated film 300 is supplied to the polarizing plate manufacturing process as it is, using an active energy ray-curable adhesive It was discovered that it became easy to produce an image distortion in the polarizing plate obtained by bonding a thermoplastic resin film together on the polarizer layer 5. When the light-polarizing laminated film 400 with a protection film was wound up and set as a roll, or when this roll was stored with a certain period of time and a roll state, it was discovered that it became easy to produce especially an image distortion.

By using the protection film 7 whose arithmetic mean roughness Ra of the surface by the side of the polarizer layer 5 is 0.150 micrometers or less, image distortion can be suppressed. From the viewpoint of effectively suppressing image distortion, the arithmetic mean roughness Ra is preferably 0.120 µm or less, more preferably 0.100 µm or less, still more preferably 0.080 µm or less, still more preferably 0.070 µm or less. is below. The arithmetic mean roughness Ra is usually 0.010 µm or more, for example, 0.020 µm or more (or 0.030 µm or more). The arithmetic mean roughness (Ra) in this specification is the arithmetic mean roughness (Ra) based on JIS B 0601:2013, and can be measured by the method described in the term of the Example mentioned later, or a method substantially equivalent to this. . Such a protection film can be used by selecting an appropriate one, for example according to grade or lot.

As the protection film 7, the thermoplastic resin film which has self-adhesiveness, the adhesive film etc. which have an adhesive layer on a support film are mentioned. The thermoplastic resin constituting the self-adhesive thermoplastic resin film is, for example, a polypropylene-based resin and a chain-type olefin-based resin such as a polyethylene-based resin. The self-adhesive thermoplastic resin film may have a single layer structure.

The support film constituting the pressure-sensitive adhesive film may include a thermoplastic resin, for example, a polyolefin-based resin such as a polyethylene-based resin, a polypropylene-based resin, or a cyclic polyolefin-based resin; polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate-based resin; (meth)acrylic resin etc. can be comprised. The pressure-sensitive adhesive layer can be composed of a (meth)acrylic pressure-sensitive adhesive, an epoxy-based pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, and the like, and is preferably a (meth)acrylic pressure-sensitive adhesive. The thickness of the pressure-sensitive adhesive layer is, for example, 1 to 40 µm, and may be 3 to 25 µm. When using an adhesive film, the protection film 7 is laminated|stacked on the light-polarizing laminated|multilayer film 300 through the adhesive layer.

The thickness of the protection film 7 may be, for example, 5-200 µm, preferably 10-150 µm, more preferably 20-120 µm, still more preferably 25-100 µm (eg, 90 µm or less). , and further 75 µm or less).

Although the protection film 7 is laminated|stacked and closely_contact|adhered to the surface on the side of the polarizer layer 5 in the light-polarizing laminated|multilayer film 300 (preferably the surface of the polarizer layer 5), the protection film 7 can be detached from it. The peeling force between the light-polarizing laminated film 300 and the protection film 7 is 0.01-0.5 N/25 mm, for example, Preferably it is 0.01-0.2 N/25 mm. When the peeling force is less than 0.01 N/25 mm, the adhesive force is too small, partial peeling of the protection film 7 occurs during handling of the light-polarizing laminated film 400 with a protection film 400, or protection of the polarizer layer 5 In some cases, it may become insufficient. Moreover, when peeling force exceeds 0.5 N/25 mm, it may become difficult to peel the protection film 7 from the light-polarizing laminated film 400 with a protection film.

The said peeling force cuts the light-polarizing laminated film 400 with a protection film to 25 mm width, acquires a measurement sample, Shimadzu Corporation precision universal testing machine "Autograph AGS-50NX" or an apparatus equivalent to this It is calculated|required by measuring the force at the time of holding the protection film 7 and light-polarizing laminated|multilayer film 300 of a measurement sample using and peeling in a 180 degree direction. The measurement of peeling force is performed in the environment of temperature 23±2 degreeC, and 50±5% of relative humidity at a peeling rate of 300 mm/min.

[5] Other processes

The manufacturing method of the light-polarizing laminated film with a protection film may include the winding-up process which winds up the obtained light-polarizing laminated film 400 with a protection film using a normal means, and obtains the light-polarizing laminated film roll with a protection film. . Or you may include the storage process of storing the obtained light-polarizing laminated film roll with a protection film in what environment further. Any environment may be a general storage environment, for example, an environment with a temperature of 23°C and a relative humidity of 55%.

The storage period in the storage step can be within 2 years, preferably within 1.5 years, more preferably within 1 year, and still more preferably within 0.5 years. By making the storage period into two years or less, image distortion can be suppressed effectively and it can prevent that the physical property of the polarizer layer 5, etc. deteriorate. Although the lower limit of a storage period is not specifically limited, For example, it can be set as 4 hours or more.

When a winding process or a winding process and a storage process are included, it will become easy to produce an image distortion in the polarizing plate obtained by bonding a thermoplastic resin film together on the polarizer layer 5 using an active energy ray-curable adhesive agent. Therefore, the present invention capable of suppressing phase distortion is particularly advantageous when it includes a winding process or a winding process and a storage process.

<Light-polarizing laminated film with protection film and its roll>

The light-polarizing laminated film 400 with a protection film shown in FIG. 5 contains the base film 30', the polarizer layer 5 containing polyvinyl alcohol-type resin, and the protection film 7 in this order do. As for the protection film 7, the arithmetic mean roughness of the surface by the side of the polarizer layer 5 is 0.150 micrometers or less. The light-polarizing laminated film roll with a protection film is a wound object of the light-polarizing laminated film 400 with a protection film.

The light-polarizing laminated film 400 with a protection film and the light-polarizing laminated film roll with a protection film may be equipped with the polarizer layer 5 laminated|stacked on both surfaces of the base film 7 .

In this case, the layer structure of the light-polarizing laminated film 400 with a protection film and the light-polarizing laminated film roll with a protection film is, for example, protection film 7 / polarizer layer 5 / base film 30' / polarizer layer It becomes (5) / protection film 7 and protection film 7 / polarizer layer 5 / base film 30' / polarizer layer 5.

The light-polarizing laminated film 400 with a protection film and the light-polarizing laminated film roll with a protection film can be manufactured suitably with the above-mentioned manufacturing method. In this case, the base film is the stretched base film 30'. Moreover, it is also possible to manufacture by laminating|stacking three individual members of a base film, a polarizer layer (polarizing film), and a protection film. In this case, the polarizer layer (polarizing film) may be a film in which a dichroic dye is adsorbed and oriented to a polyvinyl alcohol-based resin film produced by a known method from a single (single) film made of a polyvinyl alcohol-based resin. . The thickness of this polarizer layer (polarizing film) may be 1-25 micrometers, for example. A stretched film may be sufficient as a base film, and the unstretched film may be sufficient as it.

The protection film 7 is laminated on the polarizer layer 5, preferably in contact with the surface of the polarizer layer 5 (the surface opposite to the base film 30 or 30') on the polarizer layer 5 is stacked on The polarizer layer 5 may be laminated|stacked on the base film 30 or 30' via the primer layer etc. mentioned above. The base film 30 or 30', Preferably peeling from the polarizer layer 5 is possible. In addition, the base film 30 or 30' may be an optical film. In this case, the light-polarizing laminated film can be used as a polarizing plate.

The use of the protection film 7 having an arithmetic mean roughness Ra of 0.150 µm or less on the surface of the polarizer layer 5 is formed by bonding a thermoplastic resin film on the polarizer layer 5 using an active energy ray-curable adhesive. It becomes advantageous in suppressing the image distortion which may generate|occur|produce in a polarizing plate. From the viewpoint of effectively suppressing image distortion, the arithmetic mean roughness Ra is preferably 0.120 µm or less, more preferably 0.100 µm or less, still more preferably 0.080 µm or less, still more preferably 0.070 µm or less. is below. The arithmetic mean roughness Ra is usually 0.010 µm or more, for example, 0.020 µm or more (or 0.030 µm or more).

Arithmetic mean roughness Ra of the surface at the side of the protection film 7 in the polarizer layer 5 which the light-polarizing laminated film 400 with a protection film and the light-polarizing laminated film roll with a protection film have suppresses an image distortion It is preferably 0.100 µm or less, and more preferably 0.090 µm or less. The arithmetic mean roughness Ra is usually 0.010 µm or more, for example, 0.020 µm or more (or 0.030 µm or more).

About the base film 30 or 30' with which the light-polarizing laminated film 400 with a protection film and the light-polarizing laminated film roll with a protection film are equipped, the polarizer layer 5, and the protection film 7, said <protection film The technique regarding the base film 30 or 30' in the term of > the manufacturing method of an adhesion light-polarizing laminated film, the polarizer layer 5, and the protection film 7 is cited.

<Method for producing a polarizing plate>

It is a flowchart which shows the manufacturing method of the polarizing plate which concerns on one Embodiment of this invention. As shown in FIG. 6, the manufacturing method of the polarizing plate which concerns on one Embodiment of this invention is the following process:

The process of obtaining the light-polarizing laminated film with a protection film by the manufacturing method of the above-mentioned light-polarizing laminated film with a protection film,

The protection film peeling process (S50) of peeling a protection film from the light-polarizing laminated film with a protection film,

1st bonding process ( S60),

Curing process of curing the layer of the active energy ray-curable adhesive (S70)

includes

The manufacturing method of a polarizing plate may further include the base film peeling process of peeling a base film after a hardening process (S70). In addition, although not shown in FIG. 6, in the manufacturing method of a polarizing plate, between the process of obtaining a light-polarizing laminated film with a protection film, and a protection film peeling process (S50), the light-polarizing laminated film with a protection film is wound, and the piece with a protection film It may further include the process of obtaining a photo-laminated film roll. The process of obtaining the light-polarizing laminated film roll with a protection film is as having already described. When including the process of obtaining the light-polarizing laminated film roll with a protection film, a protection film peeling process (S50) is a process of peeling a protection film from the light-polarizing laminated film with a protection film unwound from the light-polarizing laminated film roll with a protection film can be

Hereinafter, each process mentioned above is demonstrated, referring drawings.

[1] Step of obtaining a light-polarizing laminated film with a protection film

About this process, the description of the claim of the said <The manufacturing method of the light-polarizing laminated film with a protection film> is cited.

[2] Protect film peeling process (S50)

With reference to FIG. 7, this process peels the protection film 7 from the light-polarizing laminated film 400 with a protection film, and is a process of obtaining the film which has the same laminated constitution as the light-polarizing laminated film 300. In this step, for example, while continuously conveying a long light-polarizing laminated film 400 with a protection film, or continuously unwinding the light-polarizing laminated film 400 with a protection film from a light-polarizing laminated film roll with a protection film, It can carry out continuously, conveying this. Film conveyance can be performed using a guide roll etc. A specific method for peeling the protection film 7 may be a normal peeling method of the protection film.

The arithmetic mean roughness Ra of the surface (or the surface of the polarizer layer 5) on the side of the polarizer layer 5 exposed by peeling of the protection film 7 is preferably 0.100 from the viewpoint of suppressing image distortion. It is micrometer or less, More preferably, it is 0.090 micrometer or less. The arithmetic mean roughness Ra is usually 0.010 µm or more, for example, 0.020 µm or more (or 0.030 µm or more).

[3] 1st bonding process (S60)

With reference to FIG. 8, this process is a protective film peeling process (S50) as a surface on the side of the polarizer layer 5 in the film which has the same layer structure as the light-polarizing laminated film 300 obtained in the protection film peeling process (S50) It is a process of laminating|stacking the 1st thermoplastic resin film 10 through the layer of an active energy ray-curable adhesive agent on the surface exposed by S50). In this process, for example, the surface of the polarizer layer 5 side of the film while continuously conveying the long film and the long 1st thermoplastic resin film 10 which have the same layer structure as the light-polarizing laminated film 300 . and/or an active energy ray-curable adhesive is applied to one side of the first thermoplastic resin film 10, these films are superposed through a layer of an active energy ray-curable adhesive, and the laminate is applied to a pair of rolls (bonding rolls) ) and the process of pressing it by passing it between them.

The 1st adhesive bond layer 15 shown in FIG. 8 is a hardened|cured material layer of the layer of the active energy ray-curable adhesive agent hardened|cured by the hardening process (S70) mentioned later. The first polarizing plate 500 shown in FIG. 8 is provided with a first thermoplastic resin film 10 which is an optical film on one side of the polarizer layer 5, and a base film 30' on the other side. It is a polarizing plate provided.

When the light-polarizing laminated film 300 has the polarizer layer 5 on both surfaces of the base film 30', the 1st thermoplastic resin film 10 is bonded together on the polarizer layer 5 of both surfaces normally, respectively. In this case, the thermoplastic resin film of the same type may be sufficient as these 1st thermoplastic resin film 10 in resin type and a structure, and a different type of thermoplastic resin film may be sufficient as it.

The layer of active energy ray-curable adhesive agent is in contact with the surface of the polarizer layer 5, and the surface of the 1st thermoplastic resin film 10 normally.

The first thermoplastic resin film 10 is an optical film, and a light-transmitting (preferably optically transparent) thermoplastic resin such as a chain polyolefin-based resin (polypropylene-based resin, etc.), a cyclic polyolefin-based resin (norvo polyolefin-based resins such as nene-based resins, etc.); Cellulose ester-based resins such as cellulose triacetate and cellulose diacetate; polyester-based resin; polycarbonate-based resin; (meth)acrylic resin; polystyrene-based resin; Or it may be a film made of a mixture or copolymer thereof. Among them, the first thermoplastic resin film 10 is made of a thermoplastic resin film with low moisture permeability, which is not necessarily easily adhered with a water-based adhesive, such as polyolefin-based resin, polyester-based resin, (meth)acrylic-based resin, polystyrene-based resin, and the like. It is a thermoplastic resin film made. Regarding the specific example of the said thermoplastic resin, the technique regarding a base film is quoted.

The protective film for protecting the polarizer layer 5 may be sufficient as the 1st thermoplastic resin film 10, and the protective film which has optical functions like retardation film and a brightness improvement film together may be sufficient as it. For example, the retardation film to which arbitrary retardation values are provided can be made by extending|stretching (uniaxial stretching, biaxial stretching, etc.) the film which consists of the said thermoplastic resin, or forming a liquid crystal layer etc. on the said film.

A surface treatment layer (coating layer) such as a hard coat layer, an anti-glare layer, an anti-reflection layer, an anti-static layer, and an anti-fouling layer may be formed on the surface on the opposite side to the polarizer layer 5 in the first thermoplastic resin film 10 . have. A surface treatment layer may be previously formed on the 1st thermoplastic resin film 10 prior to implementation of a 1st bonding process (S60), After 1st bonding process (S60) implementation or after peeling process (S80) mentioned later implementation may be formed. In addition, the first thermoplastic resin film 10 may contain one or more additives such as a lubricant, a plasticizer, a dispersant, a heat stabilizer, an ultraviolet absorber, an infrared absorber, an antistatic agent, and an antioxidant.

The thickness of the 1st thermoplastic resin film 10 becomes like this. From a viewpoint of thickness reduction of a polarizing plate, Preferably it is 90 micrometers or less, More preferably, it is 50 micrometers or less, More preferably, it is 30 micrometers or less. The thickness of the 1st thermoplastic resin film 10 is 5 micrometers or more normally from a viewpoint of intensity|strength and handleability.

The emphasis of the minute unevenness|corrugation which the surface of the polarizer layer 5 had is easy to generate|occur|produce, when the thickness of the 1st thermoplastic resin film 10 is small and rigidity is low. Therefore, the present invention capable of suppressing image distortion is particularly advantageous when the thickness of the first thermoplastic resin film 10 is small, for example, when the thickness of the first thermoplastic resin film 10 is 30 µm or less.

The first adhesive layer 15 is a layer for bonding and fixing the first thermoplastic resin film 10 to one surface of the polarizer layer 5 . The adhesive forming the first adhesive layer 15 is an active energy ray-curable adhesive containing a curable compound that is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays, and is preferably an ultraviolet-curable adhesive.

The curable compound may be a cationically polymerizable curable compound or a radical polymerizable curable compound. Examples of the cationically polymerizable curable compound include an epoxy compound (a compound having one or two or more epoxy groups in a molecule), an oxetane compound (a compound having one or two or more oxetane rings in a molecule), or Combinations of these can be mentioned. Examples of the radical polymerizable curable compound include a (meth)acrylic compound (a compound having one or two or more (meth)acryloyloxy groups in the molecule) and other vinyl compounds having a radical polymerizable double bond; or a combination thereof. You may use together a cationically polymerizable sclerosing|hardenable compound, and a radically polymerizable sclerosing|hardenable compound. An active energy ray-curable adhesive agent further contains a cationic polymerization initiator and/or a radical polymerization initiator for initiating the hardening reaction of the said curable compound normally.

Active energy ray-curable adhesives, if necessary, include cationic polymerization accelerators, ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, defoamers, antistatic agents, leveling agents, solvents, etc. It may contain additives.

In bonding the 1st thermoplastic resin film 10 to the polarizer layer 5, to the bonding surface of the 1st thermoplastic resin film 10 and/or the polarizer layer 5, adhesiveness with the polarizer layer 5 In order to improve the surface treatment (ease of adhesion treatment) such as plasma treatment, corona treatment, ultraviolet irradiation treatment, flame treatment, and saponification treatment, among others, plasma treatment, corona treatment or saponification treatment it is preferable

[4] Hardening process (S70)

With reference to FIG. 8, this process is a process of hardening the layer of the active energy ray-curable adhesive agent which the laminated body obtained by the 1st bonding process S60 has, and obtaining the 1st polarizing plate 500. Hardening of the said layer can be performed by irradiation of the active energy ray with respect to the said layer. Among them, ultraviolet light is suitable, and as a light source in this case, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excited mercury lamp, a metal halide lamp, etc. can be used.

The thickness (after hardening) of the 1st adhesive bond layer 15 is about 0.001-5 micrometers normally, Preferably it is 0.01-3 micrometers.

Since the 1st polarizing plate 500 obtained by making it above is manufactured using the said light-polarizing laminated film 400 with a protection film, when it observes from the 1st thermoplastic resin 10 side, image distortion is suppressed effectively it may have been

The arithmetic mean roughness Ra of the surface on the side of the first thermoplastic resin film 10 in the polarizer layer 5 of the first polarizing plate 500 is from the viewpoint of suppressing image distortion, preferably 0.100 µm or less and more preferably 0.090 μm or less. The arithmetic mean roughness Ra is usually 0.010 µm or more, for example, 0.020 µm or more (or 0.030 µm or more).

[5] Base film peeling process (S80)

Referring to FIG. 9 , the method for manufacturing a polarizing plate may further include a base film peeling step ( S80 ) of peeling the base film 30 ′ after the curing step ( S70 ). Thereby, the 2nd polarizing plate 600 provided with the 1st thermoplastic resin film 10 on one surface of the polarizer layer 5 is obtained. In this step, for example, while continuously conveying the long first polarizing plate 500, or continuously unwinding the first polarizing plate 500 from a roll that is a wound product of the long first polarizing plate 500, and conveying this , can be done continuously. Film conveyance can be performed using a guide roll etc. A specific method for peeling the base film 30' may be a conventional peeling method of the base film 30'.

When the second polarizing plate 600 is introduced into an image display device such as a liquid crystal display device, the first thermoplastic resin film 10 is preferably disposed outside the polarizer layer 5 (opposite to the image display element) do. The same applies to the first polarizing plate 500 . Thereby, it becomes possible to orient|orient the 1st thermoplastic resin film 10 side by which image distortion was suppressed to the visual recognition side of an image display apparatus. Bonding with respect to the image display element (liquid crystal cell etc.) of the 2nd polarizing plate 600 and the 1st polarizing plate 500 can be performed through an adhesive layer.

The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is usually made of a (meth)acrylic resin, a styrene resin, a silicone resin, etc. as a base polymer, and a crosslinking agent such as an isocyanate compound, an epoxy compound, or an aziridine compound is added thereto. It consists of a pressure-sensitive adhesive composition. Furthermore, it can also be set as the adhesive layer which contains microparticles|fine-particles and shows light-scattering property. The thickness of an adhesive layer is 1-40 micrometers normally, Preferably it is 3-25 micrometers.

[6] Other processes

The manufacturing method of a polarizing plate can include the process of bonding the 2nd thermoplastic resin film 20 together to the other surface of the polarizer layer 5 which the 2nd polarizing plate 600 has via an adhesive agent. Accordingly, with reference to Fig. 10, the first thermoplastic resin film 10 is bonded to one surface of the polarizer layer 5 through the first adhesive layer 15, and the second adhesive layer ( 25), the 3rd polarizing plate 700 by which the 2nd thermoplastic resin film 20 was bonded can be obtained.

The second thermoplastic resin film 20 is an optical film, and similarly to the first thermoplastic resin film 10, a protective film made of a thermoplastic resin exemplified above may be used. A film may be sufficient. Regarding the thickness of the surface treatment layer and the film that the second thermoplastic resin film 20 may have, the above technique described with respect to the first thermoplastic resin film 10 is cited. The first thermoplastic resin film 10 and the second thermoplastic resin film 20 may be films made of the same kind of resin or may be films made of different kinds of resins.

The 2nd adhesive bond layer 25 is a layer for adhesively fixing the 2nd thermoplastic resin film 20 to the other surface of the polarizer layer 5, and similarly to the 1st adhesive bond layer 15, the polarizer layer 5 ) is usually laminated in contact with the other surface of the polarizer layer 5 so as to be directly bonded to the polarizer layer 5 . Moreover, the 2nd adhesive bond layer 25 is also in contact with the bonding surface (surface at the side of the polarizer layer 5) of the 2nd thermoplastic resin film 20 normally.

The adhesive forming the second adhesive layer 25 may be a water-based adhesive in which an adhesive component such as polyvinyl alcohol-based resin is dissolved or dispersed in water other than an active energy ray-curable adhesive, but from the viewpoint of manufacturing efficiency, the first Like the adhesive layer 15, it is preferable that it is an active-energy-ray-curable adhesive agent. In particular, when the moisture permeability of the 2nd thermoplastic resin film 20 is low, an active energy ray-curable adhesive agent is used preferably. The active-energy-ray-curable adhesive agent which forms the 2nd adhesive bond layer 25 becomes like this. Preferably it is an ultraviolet-curable adhesive agent.

In the 3rd polarizing plate 700, the 2nd thermoplastic resin film 20 may be laminated|stacked on the other surface of the polarizer layer 5 via an adhesive layer. As for the pressure-sensitive adhesive layer, the above technique is cited.

When the third polarizing plate 700 is introduced into an image display device such as a liquid crystal display device, the second thermoplastic resin film 20 is preferably disposed on the image display element side rather than the polarizer layer 5 . Thereby, it becomes possible to orient|orient the 1st thermoplastic resin film 10 side by which image distortion was suppressed to the visual recognition side of an image display apparatus. Bonding with respect to the image display element (liquid crystal cell etc.) of the 3rd polarizing plate 700 can be performed through an adhesive layer.

[Example]

Hereinafter, although an Example and a comparative example are disclosed and this invention is demonstrated more specifically, this invention is not limited by these examples.

In the following Examples and Comparative Examples, the arithmetic mean roughness (Ra) of the surface of the protection film and the surface of the polarizer layer was measured according to the following method.

(Measurement of arithmetic mean roughness (Ra))

The arithmetic mean roughness Ra based on JIS B 0601:2013 was measured using the white interferometer "Vertscan" (made by Ryoka Systems Co., Ltd.) which is a non-contact type surface roughness measuring instrument. This white interferometer grasps the interference fringe caused by the optical path difference caused by the unevenness on the surface of the sample with a CCD camera, and converts the information on the contrast of the interference fringe into information on the height of the surface unevenness.

The procedure for measuring the arithmetic mean roughness (Ra) is as follows. First, a 20 cm x 20 cm film piece was cut out from the film used as the measurement object. This piece of film was placed on a black acrylic plate with the surface to be measured facing up, and the periphery was fixed with tape so that the surface to be measured was flat. The obtained laminate was used as a measurement sample.

The measurement sample was put on the stage of the white interferometer "Vertscan", the measurement was performed with the following apparatus settings, and the arithmetic mean roughness (Ra) was obtained.

・Magnification of 2-beam interference objective lens: 5 times

・Measurement mode: Select 『wave』

・Wavelength filter: Select 『530white』

・Scan range: -10 μm to 10 μm

· Stitching setting: 2x2, overlap rate 20%.

The observation range becomes as follows by the said setting.

·Length (x) × width (y): 1263.73 ㎛ × 1689.94 ㎛

· Height difference (z): -0.25 μm to 0.25 μm.

<Example 1>

(1) Preparation of coating solution

Polyvinyl alcohol powder (“Z-200” manufactured by Nippon Synthetic Chemical Industry Co., Ltd., average degree of polymerization 1100, saponification degree 99.5 mol%) was dissolved in hot water at 95°C to prepare a polyvinyl alcohol aqueous solution having a concentration of 3 wt% did. The obtained aqueous solution was mixed with a crosslinking agent ("Sumireize Resin 650" manufactured by Daoka Chemical Industry Co., Ltd.) in a ratio of 1 part by weight with respect to 2 parts by weight of polyvinyl alcohol powder to obtain a coating solution for forming a primer layer.

Further, polyvinyl alcohol powder (“PVA124” manufactured by Kuraray Co., Ltd., average degree of polymerization 2400, saponification degree 98.0 to 99.0 mol%) is dissolved in hot water at 95° C., and polyvinyl alcohol solution having a concentration of 8 wt% A coating liquid for forming a vinyl alcohol-based resin layer was prepared.

(2) Formation of primer layer and polyvinyl alcohol-based resin layer (production of laminated film)

Next, while continuously conveying a base film (melting point: 163° C.) having a thickness of 90 μm made of polypropylene, corona treatment is performed on one side thereof, and then the primer layer is formed using a small-diameter gravure coater on the corona treatment side. A 0.2-micrometer-thick primer layer was formed by continuously coating the coating liquid for use, and drying it at 60 degreeC for 3 minute(s). Then, while the film is continuously conveyed, the coating solution for forming a polyvinyl alcohol-based resin layer is coated on the surface of the primer layer on the base film using a lip coater, and then dried at 80° C. for 8 minutes, on the primer layer A polyvinyl alcohol-based resin layer having a thickness of 9.3 µm was formed to obtain a laminated film.

(3) Stretching step (production of stretched laminated film)

While continuously conveying the laminated film obtained in the above (2), longitudinal uniaxial stretching is performed at a stretching temperature of 140° C. to a draw ratio of 2.5 times by inter-roll stretching using a nip roll, and then, similarly, by inter-roll stretching using a nip roll At the extending|stretching temperature of 160 degreeC, longitudinal uniaxial stretching was performed so that a total draw ratio might become 5.8 times, and the stretched laminated|multilayer film was obtained. The thickness of the stretched polyvinyl alcohol-based resin layer in the stretched laminated film was 5.1 µm.

(4) Dyeing process (production of light-polarizing laminated film)

While continuously conveying the stretched film obtained in (3) above, the polyvinyl alcohol-based resin layer is dyed by immersing it in an aqueous dyeing solution at 30° C. containing iodine and potassium iodide so that the residence time is about 150 seconds, The excess dyeing solution was washed off with 10°C pure water. Then, it crosslinked by immersing continuously in the 76 degreeC crosslinking aqueous solution containing boric acid and potassium iodide so that residence time might be set to 600 second. Then, the light-polarizing laminated film which has a polarizer layer on a base film was obtained by wash|cleaning for 4 second at 10 degreeC pure water, and drying at 80 degreeC for 300 second. The thickness of the polarizer layer was 5.1 μm.

It was 0.0456 micrometers when a film piece was cut out from the obtained light-polarizing laminated film, and the arithmetic mean roughness Ra of the polarizer layer surface (surface on the opposite side to a base film) was measured according to the said measurement procedure.

(5) Protection film lamination process (production of light-polarizing laminated film with protection film)

While continuously conveying the light-polarizing laminated film obtained in the above (4), a 30 µm-thick protection film A (a polyethylene-based resin film having self-adhesiveness. Arithmetic mean roughness (Ra) of the surface on the polarizer layer side according to the above measurement procedure: 0.0815 µm) is laminated on the surface of the polarizer layer, the laminate is passed through a bonding roll, and the laminate is pressed to perform a bonding treatment, and the laminate after the bonding treatment is continuously wound, a light-polarizing laminated film roll with a protection film got it The protection film A is in contact with the surface of a polarizer layer. The pressure (nip pressure) applied with respect to the said laminated body with the bonding roll was made into 0.1 MPa.

In addition, as for the nip pressure of the bonding roll, a pressure measuring system [FUJIFILM Co., Ltd. ) manufactured FPD-305E and FPS-307E], it acquired previously by measuring the nip pressure of a press location.

The obtained light-polarizing laminated film roll with a protection film was stored in the environment of temperature 23 degreeC, and 55% of relative humidity for 2 weeks.

(6) Preparation of polarizing plate

The protection film A was peeled continuously, unwinding continuously the light-polarizing laminated film with a protection film from the light-polarizing laminated film roll with a protection film immediately after the said storage. A film piece was cut out from the light-polarizing laminated film obtained by peeling the protection film A, and according to the said measurement procedure, the arithmetic mean roughness of the polarizer layer surface (surface on the opposite side to the base film) exposed by peeling of the protection film A ( Ra) was measured and found to be 0.0998 µm.

Then, apply an ultraviolet curable adhesive (“KR-75T” manufactured by ADEKA Co., Ltd.) on the surface of the polarizer layer exposed by peeling of the protection film A using a small-diameter gravure coater so that the thickness after curing becomes about 1.0 μm Then, on the adhesive layer, a 23 μm thick thermoplastic resin film (“ZF-14” manufactured by Nippon Zeon Co., Ltd.) made of a cyclic polyolefin-based resin is laminated, and the laminate is passed through a laminating roll and laminated. By pressing a sieve to perform a bonding process, then, using a high-pressure mercury lamp, by irradiating an ultraviolet-ray with an accumulated light quantity of 200 mJ/cm ² from the base film side to harden an adhesive bond layer, it is thermoplastic on one side of a polarizer layer The resin film was laminated|stacked through the hardened|cured adhesive bond layer, and the polarizing plate provided with the base film in the other surface was obtained.

Then, conveying the obtained said polarizing plate continuously, the base film was peeled, and the polarizing plate in which the thermoplastic resin film was laminated|stacked on one side of the polarizer layer through the hardened adhesive bond layer was obtained.

(7) Evaluation of phase distortion

Under a fluorescent lamp, the polarizing plate obtained in (6) (with the base film peeled off) was visually observed from the thermoplastic resin film side, and the degree of distortion of the image of the fluorescent lamp projected on the surface of the thermoplastic resin film was evaluated according to the following evaluation criteria. did. A result is shown in Table 1.

A: In the image of the fluorescent lamp, no or little distortion is observed in the outline of the fluorescent lamp, and it is relatively better than the following B.

B: In the image of the fluorescent lamp, although slight distortion is observed in the outline of the fluorescent lamp, it is relatively better than C below.

C: In the image of the fluorescent lamp, a lot of distortion is observed in the outline of the fluorescent lamp.

<Examples 2-3, Comparative Example 1>

A light-polarizing laminated film roll with a protection film was prepared in the same manner as in Example 1 except that the following protection films B to D were used instead of the protection film A, and a polarizing plate (the base film was peeled off) was produced using this. did. About the obtained polarizing plate, the evaluation test of the image distortion similar to Example 1 was done. A result is shown in Table 1. Moreover, in Examples 2-3 and the comparative example 1, the arithmetic mean roughness Ra of the polarizer layer surface before laminating|stacking a protection film was 0.0456 micrometers similarly to Example 1.

Example 2: Protective film B (polyethylene-based resin film having a thickness of 30 µm and self-adhesiveness. Arithmetic mean roughness (Ra) of the surface on the polarizer layer side according to the above measurement procedure: 0.0690 µm);

Example 3: Protective film C (a base material made of a polypropylene resin and a 25 µm thick protective film comprising an adhesive layer laminated thereon. Arithmetic mean roughness of the surface of the polarizer layer side (adhesive layer) according to the above measurement procedure ( Ra): 0.0621 μm),

Comparative Example 1: Protective film D (polyethylene-based resin film having a thickness of 30 µm and having self-adhesiveness. Arithmetic mean roughness (Ra) of the surface on the polarizer layer side according to the above measurement procedure: 0.1559 µm).

The production process of a polarizing plate WHEREIN: A film piece was cut out from the light-polarizing laminated film obtained by peeling a protection film, and according to the said measurement procedure, the polarizer layer surface (surface on the opposite side to a base film) exposed by peeling of a protection film. When the arithmetic mean roughness (Ra) of was measured, it was 0.0618 µm in Example 2, 0.0894 µm in Example 3, and 0.1072 µm in Comparative Example 1.

5: polarizer layer, 6: polyvinyl alcohol-based resin layer, 6': stretched polyvinyl alcohol-based resin layer, 7: protection film, 10: first thermoplastic resin film, 15: first adhesive layer, 20: second Thermoplastic resin film, 25: second adhesive layer, 30: base film, 30': stretched base film, 100: laminated film, 200: stretched laminated film, 300: light-polarizing laminated film, 400: light-polarizing laminate with a protection film Film, 500: first polarizing plate, 600: second polarizing plate, 700: third polarizing plate.

Claims (9)

A step of forming a polyvinyl alcohol-based resin layer on at least one surface of the base film to obtain a laminated film;
a step of stretching the laminated film to obtain a stretched laminated film;
A process of obtaining a light-polarizing laminated film by dyeing the polyvinyl alcohol-type resin layer of the said stretched laminated|multilayer film with a dichroic dye to form a polarizer layer;
The process of laminating|stacking a protection film on the surface by the side of the said polarizer layer in the said light-polarizing laminated film, and obtaining the light-polarizing laminated film with a protection film
including,
The said protection film is the manufacturing method of the light-polarizing laminated film with a protection film whose arithmetic mean roughness of the surface by the side of the polarizer layer is 0.0621 micrometer or more and 0.150 micrometer or less. The manufacturing method according to claim 1, wherein the protection film is laminated in contact with the surface of the polarizer layer. The manufacturing method of Claim 1 or 2 which winds up the said light-polarizing laminated film with a protection film, and further includes the process of obtaining the light-polarizing laminated film roll with a protection film. The process of obtaining the light-polarizing laminated film with a protection film by the manufacturing method of Claim 1 or 2,
The process of peeling the said protection film from the said light-polarizing laminated|multilayer film with a protection film;
A step of laminating a first thermoplastic resin film through a layer of an active energy ray-curable adhesive on the surface exposed by the step of peeling the protection film as the surface on the side of the polarizer layer in the light-polarizing laminated film;
A step of curing the layer of the active energy ray-curable adhesive
A method of manufacturing a polarizing plate comprising a. Between the process of obtaining the said light-polarizing laminated film with a protection film, and the process of peeling the said protection film, the process of Claim 4 winding up the said light-polarizing laminated film with a protection film, and obtaining the light-polarizing laminated film roll with a protection film further comprising,
The process of peeling the said protection film WHEREIN: The manufacturing method which peels the said protection film from the light-polarizing laminated film with a protection film unwound from the said light-polarizing laminated film roll with a protection film. The manufacturing method of Claim 4 which further includes the process of peeling the said base film after the process of hardening the layer of the said active energy ray-curable adhesive agent. A base film, a polarizer layer comprising a polyvinyl alcohol-based resin, and a protection film in this order,
The said protection film is the light-polarizing laminated film with a protection film whose arithmetic mean roughness of the surface by the side of the polarizer layer is 0.0621 micrometer or more and 0.150 micrometer or less. The light-polarizing laminated film with a protection film of Claim 7 in which the said protection film is in contact with the surface of the said polarizer layer. The light-polarizing laminated film roll with a protection film which is a winding object of the light-polarizing laminated film with a protection film of Claim 7 or 8.

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