KR20140125384A - Polarizing laminated film and production method therefor - Google Patents

Abstract

The present invention relates to a polarizing laminated film comprising a base film, a polarizer layer, an adhesive layer and a protective film laminated in this order, wherein both ends of the polarizer layer are in contact with a base film and protection And both ends of the adhesive layer are positioned outside both ends of the polarizer layer and are positioned inside both ends of the base film and the protective film.

Description

TECHNICAL FIELD [0001] The present invention relates to a polarizing laminated film and a polarizing laminated film,

The present invention relates to a polarizing laminated film used for a polarizing plate or the like of a display device and a method for producing the same.

The polarizing plate is widely used as a polarizing light supplying element in a liquid crystal display device and also as a polarizing light detecting element. As such a polarizing plate, a polarizing film made of a polyvinyl alcohol resin has been conventionally adhered to a protective film made of triacetyl cellulose. Recently, a liquid crystal display device has been developed into a mobile device such as a notebook PC or a mobile phone, It is required to be thin and lightweight.

As a method of producing such a thin polarizing plate, a laminated film having a polarizer layer is obtained by applying a solution containing a polyvinyl alcohol resin to the surface of a base film to form a resin layer, followed by stretching and then dyeing, To obtain a polarizing laminated film, and then peeling the base film from the polarizing laminated film to obtain a polarizing plate (see, for example, Japanese Patent Application Laid-Open No. 2000-338329).

Patent Document 1: Japanese Patent Application Laid-Open No. 2000-338329

When a protective film is bonded to a laminated film having a base film and a polarizer layer to obtain a polarizing laminated film, when the continuous lamination is carried out using a bonding roll, the adhesive overflows from the end of the polarizing laminated film, And there is a problem that the adhesive flows gradually onto the back surface of the polarizing laminated film and the film itself is also contaminated. If the laminated film is rolled up in this state in a rolled state, there is a problem that blocking is caused by the adhesive flowing into the back surface of the laminated film, and a problem that the laminated film can not be stably released in the next step tends to occur. On the other hand, if the supply amount of the adhesive is reduced so that the adhesive does not overflow, there is a problem that the adhesive does not spread evenly to the end of the polarizer and the adhesion at the end is not stable.

The present invention relates to a polarizing laminated film in which a base film, a polarizer layer, an adhesive layer, and a protective film are stacked in this order, wherein the polarizer layer and the protective film are bonded with a stable adhesive force, It is another object of the present invention to provide a polarizing laminated film roll obtained by winding a polarizing laminated film, and a process for producing a polarizing laminated film.

The present invention includes the following.

[1] A polarizing laminated film comprising a base film, a polarizer layer, an adhesive layer, and a protective film stacked in this order, wherein both ends of the polarizer layer are laminated in the width direction of the polarizing laminated film, Wherein both ends of the adhesive layer are located on both sides of the polarizer layer and are positioned inside both ends of the base film and the protective film.

[2] A polarizing laminated film according to [1], wherein the polarizer layer is a polyvinyl alcohol-based resin layer in which a dichroic dye is adsorbed and oriented, and has a thickness of 10 m or less.

[3] A polarizing laminated film roll in which the polarizing laminated film according to [1] is wound.

[4] A process for producing a laminated film, comprising: a lamination step of forming a polyvinyl alcohol resin layer on at least one side of a long base film to obtain a laminated film; a stretching step of uniaxially stretching the laminated film; A dyeing step of dying the dye layer with a dichroic dye, a crosslinking step of dipping and crosslinking the resin layer of the laminated film which has been dyed in a solution containing a crosslinking agent to form a polarizer layer, And a bonding step of bonding a protective film to a surface opposite to the surface of the base film side through an adhesive layer in this order. In the laminating step, a polyvinyl alcohol resin layer is formed on both ends in the width direction of the base film In the width direction of the laminated film after the bonding, both ends of the polarizer layer are positioned inside both ends of the protective film, and in the joining step, Wherein both ends of the coalescing layer are located outside the opposite ends of the polarizer layer and are bonded so as to be positioned inside both ends of the base film and the protective film.

[5] A method for producing a polarizing laminated film according to [4], which comprises a step of cutting off a portion of a polarizing laminated film directly bonded to a base film and a protective film through an adhesive layer after the bonding step .

[6] A method for producing a polarizing plate having a peeling step of peeling off a base film from a polarizing laminated film produced by the method described in [5].

According to the present invention, it is possible to provide a polarizing laminated film in which a polarizer layer and a protective film are adhered with a stable adhesive force so that no problems such as blocking at the time of winding can be provided, and a polarizing plate can be obtained from the polarizing laminated film.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram schematically showing a cross section in the width direction of a polarizing laminated film of the present invention. Fig.
2 is a flowchart showing a method for producing a polarizing laminated film of the present invention.
3 is a top perspective view schematically showing a laminated film after each manufacturing step of the method for producing a polarizing laminated film of the present invention.

[Polishing laminated film]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram schematically showing a cross section in a width direction of a polarizing laminated film of the present invention. FIG. The polarizing laminated film of the present invention is a long polarizing laminated film in which a base film 11, a polarizer layer 12, an adhesive layer 13, and a protective film 14 are laminated in this order. In the polarizing laminated film, both ends in the width direction of the base film 11 are P1, both ends in the width direction of the polarizer layer 12 are P2, both ends in the width direction of the adhesive layer 13 are P3, The both ends P2 of the polarizer layer 12 are located on both sides of the both ends P1 of the base film 11 and both ends P4 of the protective film 14 and the both ends P3 of the adhesive layer 13 Are located outside the opposite ends P2 of the polarizer layer 12 and are positioned further inside than both ends P1 of the base film 11 and both ends P4 of the protective film 14. [

In such a configuration, the polarizer layer 12 and the protective film 14 are bonded by the adhesive layer 13 with a stable adhesive force, and the problem that the adhesive overflows from the polarizing laminated film and causes contamination of the bonding roll Do not.

(Substrate film)

As the resin used for the base film 11, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, stretchability and the like is used, and a suitable resin is selected according to the glass transition temperature (Tg) or melting point (Tm) . Specific examples of the thermoplastic resin include a polyolefin resin, a polyester resin, a cyclic polyolefin resin (norbornene resin), a (meth) acrylic resin, a cellulose ester resin, a polycarbonate resin, a polyvinyl alcohol resin , Vinyl acetate resin, polyarylate resin, polystyrene resin, polyether sulfone resin, polysulfone resin, polyamide resin, polyimide resin, and mixtures and copolymers thereof.

The base film 11 may be a single layer using only one of the above-mentioned resins, and may be a blend of two or more kinds of resins. Of course, a multi-layer film may be formed instead of a single layer.

Examples of the polyolefin-based resin include polyethylene and polypropylene, which are preferable because they can be stably drawn at a high magnification. An ethylene-polypropylene copolymer obtained by copolymerizing propylene with ethylene may also be used. Other types of monomers may be copolymerized, and examples of other types of monomers copolymerizable with propylene include ethylene and alpha -olefin. As the? -olefin, an? -olefin having 4 or more carbon atoms is preferably used, and more preferably an? -olefin having 4 to 10 carbon atoms. Specific examples of the? -Olefin having 4 to 10 carbon atoms include 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; Vinyl cyclohexane and the like. The copolymer of propylene and other monomer copolymerizable therewith may be a random copolymer or a block copolymer. The content of the constitutional unit derived from the other monomer in the copolymer can be measured by an infrared (IR) spectrum measurement according to the method described on page 616 of "Polymer Analysis Handbook" (published by Kinokuniya Bookstore, 1995) Can be obtained.

Above all, propylene homopolymer, propylene-ethylene random copolymer, propylene-1-butene random copolymer and propylene-ethylene-1-butene random copolymer are preferably used as the propylene resin constituting the propylene resin film do.

The stereoregularity of the propylene resin constituting the propylene-based resin film is preferably substantially isotactic or syndiotactic. A propylene resin film made of a propylene resin having substantially isotactic or syndiotactic stereoregularity is relatively easy to handle and has excellent mechanical strength under a high temperature environment.

The polyester-based resin is a polymer having an ester bond, and is a polycondensation product of a polyvalent carboxylic acid and a polyhydric alcohol. The polyvalent carboxylic acid to be used is mainly a divalent dicarboxylic acid, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, dimethyl naphthalenedicarboxylate, and the like. The polyhydric alcohol to be used is mainly a dihydric diol, and examples thereof include propanediol, butanediol, neopentyl glycol, cyclohexanedimethanol, and the like.

As a representative example of the polyester-based resin, polyethylene terephthalate as a copolymer of terephthalic acid and ethylene glycol can be given. Polyethylene terephthalate is a crystalline resin, but it is easy to carry out a treatment such as drawing in a state before crystallization treatment. If necessary, the crystallization treatment can be performed by a heat treatment at the time of stretching or after stretching. Further, copolymerized polyesters having lower crystallinity (or made amorphous) by further copolymerizing other types of monomers with the skeleton of polyethylene terephthalate are also preferably used. As examples of such resins, copolymers of cyclohexanedimethanol, isophthalic acid and the like are preferably used. These resins are also excellent in stretchability and can be preferably used.

Specific examples of the resin other than the polyethylene terephthalate and the copolymer thereof include polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexanedimethyl terephthalate, Hexane dimethyl naphthalate and the like. These blend resins and copolymers can also be preferably used.

As the cyclic polyolefin-based resin, a norbornene-based resin is preferably used. The cyclic polyolefin-based resin is a generic name of resins polymerized by using cyclic olefin as a polymerization unit, and examples thereof include those described in JP-A-1-240517, JP-A-3-14882, JP-A-3-122137 And resins described in, for example, JP-A-2004-346991. Specific examples thereof include ring-opened (co) polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers of cyclic olefins with alpha -olefins such as ethylene and propylene (typically, random copolymers) and unsaturated A graft polymer modified with a carboxylic acid or a derivative thereof, and a hydride thereof. Specific examples of cyclic olefins include norbornene monomers.

As the cyclic polyolefin-based resin, various products are commercially available. Specific examples include: Topas (registered trademark) (manufactured by Ticona), Aton (registered trademark) (manufactured by JSR Corporation), ZEONOR (registered trademark) (manufactured by Nippon Zeon Corporation), Zeonex ZEONEX (registered trademark) (manufactured by Nippon Zeon Co., Ltd.) and APEL (registered trademark) (manufactured by Mitsui Chemicals, Inc.).

As the (meth) acrylic resin, any suitable (meth) acrylic resin can be adopted. Examples thereof include poly (meth) acrylates such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymers, methyl methacrylate- (meth) acrylate copolymers, methyl methacrylate- Styrene copolymer (MS resin), a polymer having an alicyclic hydrocarbon group (e.g., a methyl methacrylate-cyclohexyl copolymer, a methacrylic acid methyl- (meth) acrylate copolymer, ) Norbornyl acrylate copolymer). Preferably, poly (meth) acrylate C1-6 alkyl such as poly (meth) acrylate is exemplified. As the (meth) acrylic resin, a methyl methacrylate resin having a main component (50 to 100 wt%, preferably 70 to 100 wt%) of methyl methacrylate is used.

The cellulose ester resin is an ester of cellulose and fatty acid. Specific examples of such a cellulose ester-based resin include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. These copolymers and those obtained by modifying a part of the hydroxyl groups with other kinds of substituents or the like are also cited. Of these, cellulose triacetate is particularly preferable. Many products of cellulose triacetate are available on the market, which is advantageous in terms of availability and cost. Examples of commercially available products of cellulose triacetate include Fuji TAK (registered trademark) TD80 (manufactured by Fuji Film), Fuji TAK (registered trademark) TD80UF (manufactured by Fuji Film), Fuji TAK (registered trademark) TD80UZ Ltd.), KC4UY (manufactured by Konica Minolta Opt.), And the like can be given as examples of the curable resin composition of the present invention.

The polycarbonate resin is an engineering plastic made of a polymer in which monomer units are bonded through a carbonate group, and is a resin having high impact resistance, heat resistance and flame retardancy. In addition, since it has high transparency, it is preferably used in optical applications. In optical applications, a resin called modified polycarbonate in which a polymer skeleton is modified so as to lower the photoelastic coefficient and a copolymerized polycarbonate having improved wavelength dependency are also commercially available and can be preferably used.

Such polycarbonate resins are commercially available and are commercially available and commercially available under the trade names of Panlite (registered trademark) (Dainippon Kasei Co., Ltd.), Yufilon (registered trademark) (Mitsubishi Engineering Plastics Ltd.), SD Polycar (registered trademark) Dow Co., Ltd. and Caliber 占 (Dow Chemical Co., Ltd.).

In addition to the thermoplastic resin, any appropriate additives may be added to the base film 11. Examples of such an additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a releasing agent, a coloring inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment and a colorant. The content of the thermoplastic resin exemplified above in the base film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, particularly preferably 70 to 97% by weight %to be. When the content of the thermoplastic resin in the base film is less than 50% by weight, high transparency and the like inherently possessed by the thermoplastic resin may not be sufficiently developed.

The thickness of the base film 11 can be appropriately determined, but is generally from 1 to 500 mu m, more preferably from 1 to 300 mu m, further preferably from 5 to 200 mu m in terms of workability such as strength and handling properties desirable. The thickness of the base film is most preferably 5 to 150 mu m.

The base film 11 may be subjected to a corona treatment, a plasma treatment, a flame treatment, or the like on at least the surface of the base film 11 on which the polarizing layer 12 is formed, in order to improve the adhesion with the polarizer layer 12. In order to improve the adhesion, a thin layer such as a primer layer or an adhesive layer may be formed on the surface of the base film 11 on which the polarizer layer 12 is formed. In the case of forming the primer layer, it is preferable to form over the entire surface of the base film 11. It is to be noted that the substrate film 11 referred to herein does not include an adhesive layer, a corona treated layer, or the like.

(Polarizer layer)

The polarizer layer 12 is formed by dying a polyvinyl alcohol-based resin layer with a dichroic dye, and preferably has a thickness of 10 m or less. The polyvinyl alcohol resin used for the polarizer layer 12 preferably has a degree of saponification of 90 to 100 mol%, and may be a modified polyvinyl alcohol partially modified. For example, the polyvinyl alcohol resin may be modified with about several percent by weight of an unsaturated carboxylic acid such as olefin such as ethylene or propylene, acrylic acid, methacrylic acid, crotonic acid, alkyl ester of unsaturated carboxylic acid, . The average degree of polymerization of the polyvinyl alcohol resin is not particularly limited, but is preferably 100 to 10,000, more preferably 1,500 to 10,000.

PVA 124 (saponification degree: 98.0 to 99.0 mol%), PVA 117 (saponification degree: 98.0 to 99.0 mol%) and PVA 624 (saponification degree: 98.0 to 99.0 mol%) manufactured by Kuraray Co., Ltd. are used as the polyvinyl alcohol- 95.0 to 96.0 mol%), PVA 617 (saponification degree: 94.5 to 95.5 mol%) and the like; AH-26 (saponification degree: 97.0 to 98.8 mol%), AH-22 (saponification degree: 97.5 to 98.5 mol%) and NH-18 (saponification degree: 98.0 to 99.0 mol%) manufactured by Nippon Synthetic Chemical Industry Co., ) And N-300 (saponification degree: 98.0 to 99.0 mol%); (Saponification degree: 98.0 to 99.0 mol%), JF-17L (saponification degree: 98.0 to 99.0 mol%) and JF-20 (saponification degree: 98.0 to 99.0 mol% ) And the like, and can be preferably used.

(Protective film)

The protective film 14 may be a simple protective film having no optical function or a protective film having optical functions such as a retardation film and a brightness enhancement film. Examples of the material of the protective film 14 include, but are not limited to, a cyclic polyolefin resin film, a cellulose acetate resin film made of a resin such as triacetylcellulose or diacetylcellulose, polyethylene terephthalate, polyethylene naphthalate, A polyester resin film made of a resin such as polybutylene terephthalate, a polycarbonate resin film, an acrylic resin film, a polypropylene resin film, and the like.

Examples of the cyclic polyolefin resin include commercially available products such as Topas TM manufactured by Ticona, ATON TM manufactured by JSR Corporation, ZEONOR TM manufactured by Nippon Zeon Co., ZEONEX (manufactured by Nippon Zeon Co., Ltd.) and APEL (registered trademark) manufactured by Mitsui Chemicals, Inc. are preferably used. When a film of such an annular polyolefin-based resin is formed into a film, known methods such as a solvent casting method and a melt extrusion method are appropriately used. In addition, pre-formed films such as Essen (registered trademark) (manufactured by Sekisui Chemical Co., Ltd.), SCA40 (manufactured by Sekisui Chemical Co., Ltd.), Zeonoa (registered trademark) A commercial product of a film of a ring-shaped polyolefin resin may be used.

The cyclic polyolefin-based resin film may be uniaxially stretched or biaxially stretched. By stretching, an arbitrary retardation value can be imparted to the cyclic polyolefin-based resin film. The stretching is usually carried out while releasing the film roll, and is stretched in the heating direction in the heating direction, the direction perpendicular to the traveling direction of the roll, or both directions. The temperature of the heating furnace is usually in the range from the vicinity of the glass transition temperature of the cyclic polyolefin-based resin to the glass transition temperature + 100 ° C. The magnification of the stretching is usually 1.1 to 6 times, preferably 1.1 to 3.5 times in one direction.

Since the surface activity of the cyclic polyolefin-based resin film is generally inferior, the surface to be bonded to the polarizer layer is preferably subjected to surface treatment such as plasma treatment, corona treatment, ultraviolet ray irradiation treatment, frame (flame) treatment and saponification treatment . Among them, a plasma treatment and a corona treatment which can be performed relatively easily are preferable.

As the cellulose acetate based resin film, suitable commercially available products such as Fuji Tack (registered trademark) TD80 (manufactured by Fuji Film), Fuji Tack (registered trademark) TD80UF (manufactured by Fuji Film) KC4UY (manufactured by Konica Minolta Opt), KC8UX2M (manufactured by Konica Minolta Opt) and TD80UZ (manufactured by Fuji Film Co., Ltd.), Fuji Tack (registered trademark) TD40UZ (manufactured by Fuji Film) Can be used.

A liquid crystal layer or the like may be formed on the surface of the cellulose acetate resin film in order to improve the viewing angle characteristics. Further, in order to impart a retardation, an acetate cellulose based resin film may be stretched. The cellulose acetate-based resin film is subjected to saponification treatment in order to enhance adhesion with the polarizing film. As the saponification treatment, a method of immersing in an aqueous solution of an alkali such as sodium hydroxide or potassium hydroxide can be adopted.

On the surface of the protective film 14 as described above, an optical layer such as a hard coat layer, an antiglare layer, and an antireflection layer may be formed. The method of forming such an optical layer on the surface of the protective film 14 is not particularly limited, and a known method can be used.

The thickness of the protective film 14 is preferably thin because of the requirement for thinning, preferably 88 탆 or less, and more preferably 48 탆 or less. When the thickness is excessively thin, the strength is lowered and the workability is deteriorated. Therefore, it is preferable that the thickness is 5 m or more.

(Adhesive layer)

The adhesive used for forming the adhesive layer 13 for bonding the protective film 14 and the polarizer layer 12 may be an aqueous adhesive using, for example, a polyvinyl alcohol resin aqueous solution, a water-based liquid type urethane emulsion adhesive, or the like . When an acetic acid cellulose based resin film that has been subjected to hydrophilization treatment by saponification treatment or the like is used as the protective film 14, a polyvinyl alcohol resin aqueous solution is preferably used as an aqueous adhesive for bonding with the polarizer layer 12. The polyvinyl alcohol resin used as the adhesive includes a vinyl alcohol homopolymer obtained by saponifying polyvinyl acetate which is a homopolymer of vinyl acetate, a vinyl alcohol homopolymer obtained by saponifying a copolymer of vinyl acetate and another monomer copolymerizable therewith, Based copolymers, and further modified polyvinyl alcohol polymers obtained by partially modifying hydroxyl groups thereof. As the water-based adhesive, polyaldehyde, a water-soluble epoxy compound, a melamine compound, a zirconia compound, a zinc compound or the like may be added as an additive.

Further, a photo-curable adhesive may be used as the adhesive when the polarizer layer 12 and the protective film 14 are bonded. The photo-curing adhesive referred to herein is an adhesive that cures by irradiating active energy rays such as ultraviolet rays, and includes, for example, a polymerizable compound and a photopolymerization initiator, a photoreactive resin, a binder resin and a photoreactive crosslinking agent And the like. Examples of the polymerizable compound include photopolymerizable monomers such as a photocurable epoxy monomer, a photocurable acrylic monomer, and a photocurable urethane monomer, and oligomers derived from these monomers. Examples of the photopolymerization initiator include those that generate active species such as neutral radicals, anion radicals, and cation radicals by irradiating active energy rays such as ultraviolet rays. As the photocurable adhesive containing the polymerizable compound and the photopolymerization initiator, it is preferable to include a photocurable epoxy-based monomer and a photocationic polymerization initiator.

[Polishing laminated film roll]

The polarizing laminated film roll of the present invention is produced by winding the laminated film having a long length. In the polarizing laminated film roll of the present invention, the adhesive does not overflow from the laminated film, so that the blocking caused by the overflowing adhesive can be suppressed.

[Method for producing a polarizing laminated film]

2 is a flowchart showing a method for producing a polarizing laminated film of the present invention. Fig. 3 is a top perspective view schematically showing a laminated film after each manufacturing step in the method for producing a polarizing laminated film of the present invention. Fig. The manufacturing method of the present invention comprises a lamination step (S10) of forming a polyvinyl alcohol resin layer (12) on at least one side of a long base film (11) to obtain a laminated film, (S30) of dyeing a resin layer of a laminated film subjected to uniaxial stretching with a dichroic dye; and dipping the resin layer of the dyed laminated film in a solution containing a cross-linking agent and cross- (S50) of bonding the protective film (14) to the surface of the polarizer layer on the side opposite to the base film side of the cross-linked laminated film through the adhesive layer , In this order. In the bonding step (S50), preferably, the infeed bonding is performed such that the laminated film and the protective film 14 are overlapped between the pair of bonding rolls.

In the lamination step (S10), in the base film 11 shown in Fig. 3 (a), the resin layer 12 is formed only in the region inside the dotted line P2 as shown in Fig. 3 (b) A portion 11a where the polyvinyl alcohol resin layer is not formed is formed in an area outside the area P2. As a method of forming the resin layer 12, for example, a solution containing a polyvinyl alcohol resin is not applied to a region outside the dotted line P2 in the base film 11, A method in which a solution containing an alcohol-based resin is applied and then dried. By forming the portion (uncoated portion) 11a on which the resin layer 12 is not formed in this manner, even if the adhesive is fed sufficiently to the end of the polarizer layer in the bonding step (S50), the adhesive does not flow on the back surface of the adhesive, Whereby a photocurable laminated film can be obtained. By forming the uncoated portion 11a, it is possible to suppress the phenomenon that both ends of the base film 11 are bent toward the coated surface of the solution containing the resin when the laminated film is dried. The dotted line P2 defining the unapplied portion 11a is preferably within 0.5 cm or more, preferably 1 cm or more, and more preferably 2 cm or more inside the both ends in the width direction of the base film 11 . With such a numerical value range, it is possible to more reliably obtain an effect of preventing the adhesive from flowing on the back surface of the adhesive. The position of the dotted line P2 is preferably within 50 cm or less from both ends in the width direction of the base film 11, more preferably within 30 cm or less, and further preferably within 20 cm or less .

3 (c), the adhesive layer is formed up to the dotted line P3 which is outside the both ends of the polarizer layer 12 in the width direction so as to cover the entire polarizer layer 12 And the protective film 14 is bonded through this adhesive layer. The dotted line P3 defining the area of the adhesive layer can be determined from both ends of the polarizer layer to the outside, for example, within a range of 0.5 cm to 50 cm.

In order to adjust the application range of the adhesive layer to a predetermined width, the supply amount or the application amount of the adhesive, the application pressure by the compression bonding apparatus (the distance between the bonding rolls when the bonding roll is used) . In the case of continuous bonding with a long film, an adhesive is continuously fed between the films, and an excessive amount of adhesive overflowing from the end in the width direction of the laminated film through the adhesive layer is continuously The bonding step (S50) can be carried out while suction is carried out. In this case, however, the width of the adhesive layer can also be adjusted by adjusting the suction amount of the adhesive.

The protective film 14 is selected so that the length in the width direction is longer than the length in the width direction of the adhesive layer so that the entire adhesive layer is covered with the protective film 14. That is, in the width direction of the laminated film after the lamination, both ends of the polarizer layer are positioned inside both ends of the protective film, both ends of the adhesive layer are located outside both ends of the polarizer layer, Respectively. The protective film 14 is not limited as long as the length in the width direction is longer than the width in the width direction of the adhesive layer, but is preferably 0.5 cm or more, more preferably 1 cm or more, Preferably, a length of at least 2 cm is selected.

According to the manufacturing method of the present invention, in the bonding step (S50), the entire polarizer layer is covered with the adhesive layer, so that the polarizer layer and the protective film are bonded with a stable adhesive force, And the protective film are formed so as to be located on the inner side than both ends of the protective film, the adhesive does not overflow, so that contamination of the bonding roll and the polarizing laminated film by the adhesive can be prevented.

The polarizing laminated film produced through the above process is preferably wound to constitute a polarizing laminated film roll. In the polarizing laminated film, since the contamination in the adhesive is suppressed, the occurrence of blocking at the time of winding can be prevented, so that there is no problem such as difficulty in releasing in the subsequent process.

After the joining step (S50), the polarizing laminated film is cut at the same position as the both ends of the polarizer layer 12 or at positions slightly inward of the both ends of the polarizer layer 12 to remove the ends, A peeling process may be performed. A film obtained by the peeling process can be used as a polarizing plate. The slicing of the polarizing laminated film is preferably a method capable of continuously processing a long roll or the like. The method is not particularly limited. For example, a method generally called a slitter can be preferably used.

An example of a slitter is a method using a razor blade called a laser blade. In the method using the same laser blade, in particular, a hollow cut slit in the air without providing a backup guide, and a groove roll method in which a blade is inserted into a slotted roll to stabilize skewing of the slit as a backup guide. In addition, a method of slitting two sheets of circular blades called shear blades by applying contact pressure to the lower blade of the upper blades while rotating the blades in accordance with the conveyance of the film, or by pressing a blade called a shearing blade or a scoring blade on a quenching roll or the like A method of slitting, and a method of slitting two sheets of shear blades together while cutting them like scissors can be used. Among them, the "groove roll method using a laser blade", which is a method in which the slit position of the film can be easily changed and the running is easily stabilized, is preferably used.

In the above-described lamination step (S10), a polyvinyl alcohol resin layer may be formed on both sides of the base film, and a protective film may be bonded to the two polarizer layers in the bonding step (S50). Hereinafter, each step will be described in detail.

[Resin layer forming step (S10)]

Here, a polyvinyl alcohol-based resin layer is formed on at least one surface of the base film to obtain a laminated film. As a method of forming the resin layer, for example, a method in which a solution containing a polyvinyl alcohol resin is applied to at least one side of a base film and then dried. Materials suitable for the base film and the polyvinyl alcohol resin are as described in the description of the polarizing laminated film. The base film is preferably one capable of being stretched in a temperature range suitable for stretching the polyvinyl alcohol resin.

The thickness of the resin layer after drying is preferably more than 3 占 퐉 and not more than 30 占 퐉, more preferably 5 to 20 占 퐉. If the thickness is less than 3 mu m, the resulting film becomes excessively thin after stretching, resulting in marked deterioration of dyeability. When the thickness exceeds 30 mu m, the thickness of the finally obtained polarizer layer may exceed 10 mu m.

The resin layer is preferably formed by applying a polyvinyl alcohol resin solution obtained by dissolving a polyvinyl alcohol resin powder in a good solvent onto one surface of a base film and drying the solvent by evaporation. By forming the resin layer in this way, it becomes possible to form the resin layer thin. Examples of the method of applying the polyvinyl alcohol resin solution to the base film include a roll coating method such as a wire bar coating method, a reverse coating method and a gravure coating method, a die coating method, a comma coating method, a lip coating method, a spin coating method, Method, a fountain coating method, a dipping method, a spraying method, and the like can be suitably selected and adopted by a known method. The drying temperature is, for example, 50 to 200 占 폚, preferably 60 to 150 占 폚. The drying time is, for example, 2 to 20 minutes.

Further, in order to improve the adhesion between the base film and the polyvinyl alcohol resin, a primer layer may be formed between the base film and the resin layer. The primer layer is preferably formed from a composition containing a crosslinking agent or the like in a polyvinyl alcohol-based resin from the viewpoint of adhesion.

[Stretching step (S20)]

Here, the laminated film composed of the base film and the resin layer is uniaxially stretched. Preferably, uniaxial stretching is performed so that the stretching magnification is 5 times to 17 times or less. More preferably not more than 5 times but not more than 8 times. If the stretching magnification is 5 times or less, the resin layer made of the polyvinyl alcohol resin is not sufficiently oriented, resulting in a problem that the degree of polarization of the polarizer layer is not sufficiently increased. On the other hand, if the stretching magnification exceeds 17 times, the laminated film tends to be broken at the time of stretching, and the thickness of the stretched film becomes thinner than necessary, which may lower the workability and handling property in subsequent steps. The stretching process in the stretching process (S20) is not limited to stretching in one stage but may be performed in multiple stages. In this case, the drawing step after the second step may be performed in the drawing step (S20), but may be performed simultaneously with the processing in the dyeing step (S30) or the crosslinking step (S40). When stretching is performed in such a multi-stage, the stretching process is performed so that the total stretching process is combined so that the stretching ratio exceeds 5 times.

In the stretching step (S20), it is possible to perform a longitudinal stretching treatment for the longitudinal direction of the laminated film and a transverse stretching treatment for stretching in the width direction. Examples of the longitudinal stretching method include a roll-to-roll stretching method and a compression stretching method, and the transverse stretching method includes a tenter method and the like.

The stretching treatment can adopt both the wet stretching method and the dry stretching method, but the use of a dry stretching method is preferable in that the temperature at which the laminated film is stretched can be selected from a wide range.

[Dyeing process (S30)]

Here, the resin layer of the laminated film after stretching is dyed with a dichroic dye. Examples of the dichroic dye include iodine and organic dyes. Examples of organic dyes include red dyes such as Red BR, Red LR, Red R, Pink LB, Rubin BL, Borde GS, Sky Blue LG, Lemon Yellow, Blue BR, Blue 2R, Navy RY, Green LG, Violet LB, H, Black B, Black GSP, Yellow 3G, Yellow R, Orange LR, Orange 3R, Scarlet GL, Scarlet KGL, Kongogred, Brilliant Violet BK, Supra Blue G, Supra Blue GL, Supra Orange GL, , Direct First Orange S, First Black, and the like can be used. These dichroic substances may be used singly or in combination of two or more.

The dyeing step is carried out, for example, by immersing the entire laminated film in a solution (dyeing solution) containing the dichroic dye. As the dyeing solution, a solution obtained by dissolving the dichroic dye in a solvent can be used. As a solvent for the dyeing solution, water is generally used, but an organic solvent having compatibility with water may be further added. The concentration of the dichroic dye is preferably 0.01 to 10% by weight, more preferably 0.02 to 7% by weight, and particularly preferably 0.025 to 5% by weight.

When iodine is used as the dichroic dye, it is preferable to further add iodide because the dyeing efficiency can be further improved. 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 addition ratio of these iodides is preferably 0.01 to 20% by weight in the dyeing solution. Among iodides, it is preferable to add potassium iodide. In the case of adding potassium iodide, the ratio of iodine to potassium iodide is preferably in the range of 1: 5 to 1: 100, more preferably 1: 6 to 1:80, 7 to 1: 70.

The immersing time of the laminated film to the dyeing solution is not particularly limited, but it is preferably in the range of 15 seconds to 15 minutes, and more preferably 30 seconds to 3 minutes. The temperature of the dyeing solution is preferably in the range of 10 to 60 占 폚, and more preferably in the range of 20 to 40 占 폚.

The dyeing treatment may be carried out before or during the stretching step, but it is preferable that the non-stretched film is subjected to a stretching step so that the dichroic dye adsorbed on the polyvinyl alcohol resin can be favorably oriented. At this time, it may be simply stained with a target magnification in advance, or may be a method in which a target having been previously stretched at a low magnification is stretched again during dyeing to reach the target magnification as a whole. Further, in the case of further stretching in the subsequent crosslinking treatment, the stretching at a low magnification may also be terminated here. In this case, the crosslinking treatment may be timely adjusted so as to reach the target magnification.

[Crosslinking Step (S40)]

The dyeing step (S30) is followed by a crosslinking step (S40). The crosslinking step can be carried out, for example, by immersing a laminated film obtained through the dyeing step (S30) in a solution (crosslinking solution) containing a crosslinking agent. As the crosslinking agent, conventionally known materials can be used. Boron compounds such as boric acid and borax, and glyoxal and glutaraldehyde. These may be used alone or in combination of two or more.

As the crosslinking solution, a solution in which a crosslinking agent is dissolved in a solvent can be used. As the solvent, for example, water may be used, but an organic solvent which is compatible with water may be further contained. The concentration of the cross-linking agent in the cross-linking solution is not limited thereto, but is preferably in the range of 1 to 20 wt%, and more preferably in the range of 6 to 15 wt%.

Iodide may be added to the crosslinking solution. By adding iodide, the polarization characteristics in the plane of the resin layer can be made more uniform. 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 content of iodide is 0.05 to 15% by weight, more preferably 0.5 to 8% by weight.

The immersing time of the laminated film in the crosslinking solution is preferably 15 seconds to 20 minutes, more preferably 30 seconds to 15 minutes. The temperature of the crosslinking solution is preferably in the range of 10 to 90 占 폚.

The crosslinking step may be carried out simultaneously with the dyeing step by blending the crosslinking agent into the dyeing solution. It is also possible to simply cross-link the one drawn in advance at the target magnification, and perform the cross-linking treatment and the stretching treatment at the same time. The stretched film stretched at a low magnification in the stretching step in advance may be stretched again during the crosslinking treatment so as to reach the target magnification as a whole.

It is preferable to carry out a cleaning step after the crosslinking step. In the washing step, a water washing treatment can be performed. The water washing treatment can be usually carried out by immersing the drawn film in purified water such as ion-exchanged water or distilled water. The water washing temperature is usually in the range of 3 to 50 캜, preferably 4 to 20 캜. The immersion time is usually from 2 to 300 seconds, preferably from 3 to 240 seconds.

The cleaning step may be a combination of a cleaning treatment with a iodide solution and a water washing treatment, or a solution in which a liquid alcohol such as methanol, ethanol, isopropyl alcohol, butanol, or propanol is blended. By performing the above steps, the resin layer has a function as a polarizer. In the present specification, a resin layer having a function as a polarizer is referred to as a polarizer layer.

[Bonding step (S50)]

Here, a protective film is bonded to a surface of the polarizer layer on the side opposite to the side of the substrate film side through an adhesive layer to obtain a polarizing laminated film. Materials suitable for the protective film are as described in the description of the polarizing laminated film. Further, materials suitable for the adhesive are the same as those described in the explanation of the polarizing laminated film, and for example, an aqueous adhesive or a photo-curable adhesive can be used.

A method of bonding the polarizer layer and the protective film using an aqueous adhesive is not particularly limited. For example, an adhesive may be uniformly applied to the surface of the polarizer layer and / or the protective film, and the other film may be laminated on the application surface, And the like. As a method of applying the adhesive to the surface of the polarizer layer and / or the protective film, for example, a method of disposing an end of a nozzle for adhesive feed between a polarizer layer and a protective film and supplying an adhesive from the nozzle using a pump or the like A method of applying an adhesive to the surface of the polarizer layer and / or the protective film by a method such as a flexographic method, a Meyer bar coating method, a gravure coating method, a comma coater method, a doctor plate method, a die coating method, a dip coating method, .

When an aqueous adhesive is used, the laminated film is dried to remove water contained in the aqueous adhesive after bonding the polarizer layer and the protective film. The temperature of the drying furnace is preferably 30 to 90 占 폚. If the temperature is lower than 30 占 폚, the polarizer layer surface and the protective film surface tend to peel off easily. If it is 90 DEG C or higher, there is a fear that the optical performance is deteriorated by heat. The drying time can be 10 to 1000 seconds, and is preferably 60 to 750 seconds, and more preferably 150 to 600 seconds from the viewpoint of productivity.

After drying, it may be cured at a room temperature or a slightly higher temperature, for example, about 20 to 45 캜 for about 12 to 600 hours. The temperature at the time of curing is generally set lower than the temperature adopted at the time of drying.

As a method for bonding the polarizer layer and the protective film with a photo-curing adhesive, conventionally known methods can be used. For example, a softening method, a Meyer bar coating method, a gravure coating method, a comma coater method, a doctor plate method, , A dip coating method, a spraying method, or the like, an adhesive is applied to the bonding surface of the polarizer layer and / or the protective film, and the two are overlapped with each other. The "soft method" is a method in which a polarizing film or a protective film to be coated is moved in a substantially vertical direction, in a substantially horizontal direction, or in an inclined direction therebetween while an adhesive is applied to spread the adhesive.

An adhesive is applied to the surface of the polarizer layer or the protective film, and then the polarizing film and the protective film are bonded to each other with a nip roll or the like interposed therebetween through the adhesive application surface. A method of dropping an adhesive between the polarizer layer and the protective film in a state where the polarizer layer and the protective film are partially overlapped with each other, and then pressing the laminated film with a roll or the like to uniformly press and spread. In this case, metal, rubber, or the like can be used as the material of the roll. Further, a method of dropping an adhesive between the polarizer layer and the protective film, then passing the laminated film between the rolls and the roll, and pressing and pressing the laminated film are also preferably adopted. In this case, these rolls may be made of the same material or different materials. The thickness of the adhesive layer after bonding using the nip roll or the like before drying or curing is preferably 5 m or less and 0.01 m or more.

A surface treatment such as a plasma treatment, a corona treatment, an ultraviolet ray irradiation treatment, a frame (flame) treatment or a saponification treatment may be suitably performed on the adhesion surface of the polarizer layer and / or the protective film. As the saponification treatment, there may be mentioned a method of immersing in an aqueous solution of an alkali such as sodium hydroxide or potassium hydroxide.

When a photo-curable resin is used as the adhesive, the photo-curing adhesive is cured by bonding the polarizing film and the protective film and then irradiating with an active energy ray. A light source of an active energy ray is not particularly limited, but an active energy ray having a light emission distribution at a wavelength of 400 nm or less is preferable. Specifically, a low energy mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, A wave excitation mercury lamp, a metal halide lamp and the like are preferably used.

The light irradiation intensity for the photo-curable adhesive is appropriately determined depending on the composition of the photo-curable adhesive and is not particularly limited, but it is preferable that the irradiation intensity in the wavelength range effective for activation of the polymerization initiator is 0.1 to 6000 mW / cm 2. When the irradiation intensity is not less than 0.1 mW / cm 2, the reaction time is not excessively long. When the irradiation intensity is not more than 6000 mW / cm 2, the heat radiated from the light source and the heat generated during curing of the photo-curing adhesive deteriorate the yellowing of the epoxy resin, There is little fear of occurrence. The light irradiation time for the photo-curing adhesive is applied according to the photo-curable adhesive to be cured and is not particularly limited, but it is preferable that the accumulated light quantity represented by the product of the irradiation intensity and the irradiation time is set to 10 to 10,000 mJ / Do. When the accumulated light quantity for the photo-curable adhesive is 10 mJ / cm 2 or more, a sufficient amount of the active species derived from the polymerization initiator can be generated to more surely advance the curing reaction. When the amount is 10,000 mJ / cm 2 or less, So that good productivity can be maintained. The thickness of the adhesive layer after irradiation with active energy rays is usually about 0.001 to 5 mu m, preferably 0.01 mu m or more and 2 mu m or less, more preferably 0.01 mu m or more and 1 mu m or less.

When the photo-curable adhesive is cured by irradiation of an active energy ray, it is preferable to perform curing under such a condition that various functions of the polarizing plate are not deteriorated, such as the degree of polarization, transmittance and hue of the polarizing film, and transparency of the protective film.

[Peeling Process]

In the manufacturing method of the present invention, after the bonding step (S50) of bonding the protective film to the polarizer layer, the peeling step of the base film can be performed. In the peeling step of the base film, the base film is peeled from the laminated film. The method of peeling the base film is not particularly limited, and can be peeled off in the same manner as the peeling process of the peeling film performed in a polarizing plate to which a usual pressure-sensitive adhesive is applied. After the joining step (S50), it may be peeled off as it is, or it may be peeled off after setting the peeling step separately after winding in a roll form.

Example

[Example 1]

(1) Production of base film

(Homopolymer of propylene), which is a homopolymer of propylene, on both sides of a resin layer composed of a random copolymer of propylene / ethylene containing about 5% by weight of an ethylene unit (" Sumitomonobrene W151 ", manufactured by Sumitomo Chemical Co., And a resin layer made of propylene ("Sumitomonoblen FLX80E4" manufactured by Sumitomo Chemical Co., Ltd., melting point Tm = 163 ° C) were disposed on a base film roll having a three-layer structure by coextrusion molding using a multilayer extrusion molding machine. The total thickness of the obtained base film rolls was 100 占 퐉, and the thickness ratio (FLX80E4 / W151 / FLX80E4) of each layer was 3/4/3.

(2) Formation of primer layer

Polyvinyl alcohol powder ("Z-200" manufactured by Nippon Synthetic Chemical Industry Co., Ltd., average polymerization degree: 1100, average 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% did. 5 parts by weight of a crosslinking agent (" Sumirejin 650 ", manufactured by Sumitomo Chemical Co., Ltd.) was added to the obtained aqueous solution in an amount of 6 parts by weight of polyvinyl alcohol powder. The obtained mixed aqueous solution was continuously coated on the corona-treated surface of the substrate film roll subjected to the corona treatment using a gravure coater and dried at 80 DEG C for 10 minutes to form a primer layer having a thickness of 0.2 mu m to form a primer layer / Thereby forming a film comprising the constitution of the base film. At this time, the primer layer was formed over the full width of the substrate film.

(3) Laminating process

A polyvinyl alcohol aqueous solution having a concentration of 8% by weight was prepared by dissolving polyvinyl alcohol powder ("PVA124" manufactured by Kuraray Co., Ltd., average degree of polymerization: 2400, average degree of saponification: 98.0 to 99.0 mol%) in hot water at 95 ° C. The resulting aqueous solution was continuously applied on one primer layer of a base film using a comma coater and dried at 80 ° C for 5 minutes to obtain a three-layer structure laminated layer composed of a base film / primer layer / polyvinyl alcohol- A film roll was produced. The thickness of the resin layer made of the polyvinyl alcohol resin was 10.6 mu m. At the time of application, a polyvinyl alcohol aqueous solution was not applied to areas within 3.0 cm from both ends of the base film, and the area was made unformed. That is, the length of the resin layer in the width direction is 6 cm shorter than the length in the width direction of the base film.

(4) Drawing process

The laminated film was uniaxially stretched 4.3 times in the longitudinal direction at a stretching temperature of 160 DEG C in a roll-to-roll pneumatic stretching apparatus, and then wound up to obtain a laminated film roll. The thickness of the obtained laminated film was 55.2 占 퐉, and the thickness of the polyvinyl alcohol-based resin layer was 6.3 占 퐉.

(5) dyeing process, crosslinking process

The laminated film roll after stretching was subjected to a dyeing step and a crosslinking step in the following order. First, the laminated film was immersed in a dyeing solution at 30 DEG C, which is an aqueous solution containing iodine and potassium iodide at 30 DEG C, for a retention time of about 150 seconds to dye the polyvinyl alcohol-based resin layer (dyeing step) The excess iodine solution was rinsed with pure water at 10 ° C. Next, the substrate was immersed in a crosslinking solution at 72 캜, which is an aqueous solution containing boric acid and potassium iodide, at a residence time of about 600 seconds (crosslinking step) to form a polarizer layer with a resin layer. Thereafter, the film was washed with pure water at 10 占 폚 for 4 seconds, and then dried at 80 占 폚 for 300 seconds to obtain a laminated film roll.

(6) Bonding process

First, a polyvinyl alcohol aqueous solution having a concentration of 3% by weight was prepared by dissolving polyvinyl alcohol powder ("KL-318" manufactured by Kuraray Co., Ltd., average degree of polymerization: 1800) in hot water at 95 ° C. 1 part by weight of a cross-linking agent (" Sumirejin 650 ", manufactured by Sumitomo Chemical Co., Ltd.) was mixed with 2 parts by weight of the polyvinyl alcohol powder to obtain an adhesive solution.

Next, a protective film ("KC4UY" manufactured by Konica Minolta Optics Co., Ltd.) made of triacetyl cellulose (TAC) having a width of 8.0 cm larger than the width of the polarizer layer was laminated on the side of the polarizing layer side of the obtained laminated film, Was set so as to be located outside the 4.0-cm-thick polarizer layer, the adhesive solution was fed between the two films, and then the film was joined with a bonding roll. At this time, the feed amount of the adhesive solution was adjusted such that both ends in the width direction of the adhesive layer were located outside both ends of the polarizer layer, and inside both ends of the protective film and the base film. Thereafter, the film was dried at 80 DEG C for 5 minutes to obtain a polarizing laminated film, which was wound to obtain a polarizing laminated film roll. The obtained polarizing laminated film was a long polarizing laminated film composed of five layers of a base film / primer layer / polarizer layer / adhesive layer / protective film.

The resulting polarizing laminated film was in a satisfactory state because the adhesive did not overflow and the adhesive did not leak onto the surface of the polarizing laminated film.

The cross section of the obtained polarizing laminated film in the width direction was a cross section as shown in Fig. The length in the width direction of the adhesive layer 13 was 3.2 cm shorter than the length in the width direction of the base film 11 and the distance between the end P3 of the adhesive layer 13 and the end P1 of the base film 11 was 1.6 cm. The length in the width direction of the polarizer layer 12 was shorter by 2.0 cm than the length in the width direction of the adhesive layer 13 and the distance between the end P2 of the polarizer layer 12 and the end P3 of the adhesive layer 13 was 1.0 cm. The length in the width direction of the adhesive layer 13 is 8.0 cm shorter than the width in the width direction of the protective film 14 and the distance between the end P3 of the adhesive layer 13 and the end P4 of the protective film 14 is 4.0 cm Respectively.

The obtained polarizing laminated film roll was provided on the rewinder to loosen the polarizing laminated film, but there was no blocking or the like, and it was able to be released smoothly even when it was loosened in the next step. In addition, the both ends were slit with the laser blades, and the protective film and the base film were directly bonded through the adhesive layer and the portion where the polarizer layer was not laminated was removed while being loosened continuously, but the slit blade was stable and the end was cleanly removed I could.

Further, the base film was peeled off from the polarizing laminated film obtained by slitting. Since the end portion is slit, the film can be smoothly peeled off, and a polarizing plate comprising a protective film / adhesive layer / polarizer layer / primer layer can be obtained.

[Example 2]

As a base material, a polyester base (PETG manufactured by DAICHEI CO., LTD.) In which three kinds of monomers of 1,4-cyclohexane dimethanol, terephthalic acid and ethylene glycol were copolymerized was used. The thickness of the base film was 70 mu m. A primer layer and a polyvinyl alcohol resin layer were formed in the same manner as in Example 1 to prepare a laminated film composed of a substrate film / primer layer / polyvinyl alcohol resin layer (laminating step). The thickness of the primer layer was 0.2 탆, and the thickness of the polyvinyl alcohol resin layer was 10.4 탆. Here again, the polyvinyl alcohol aqueous solution was not applied to regions at both ends within 3.0 cm from the end of the base film, and an uncoated portion was formed.

The laminated film was subjected to free-end uniaxial stretching 4.0 times in the machine direction at a stretching temperature of 110 DEG C (stretching step) to obtain a laminated film roll. The thickness of the obtained laminated film roll was 40.5 占 퐉, and the thickness of the polyvinyl alcohol-based resin layer was 6.2 占 퐉.

The obtained laminated film was subjected to a dyeing step in the same manner as in Example 1, followed by washing and drying to obtain a laminated film. A protective film was bonded to the obtained laminated film in the same manner as in Example 1 (bonding step) to obtain a long polarizing laminated film consisting of five layers of a base film / primer layer / polarizer layer / adhesive layer / protective film.

The cross section of the obtained polarizing laminated film in the width direction was a cross section as shown in Fig. The length in the width direction of the adhesive layer 13 was 3.0 cm shorter than the width in the width direction of the base film 11 and the distance between the end P3 of the adhesive layer 13 and the end P1 of the base film 11 was 1.5 cm. The length in the width direction of the polarizer layer 12 was shorter by 2.0 cm than the length in the width direction of the adhesive layer 13 and the distance between the end P2 of the polarizer layer 12 and the end P3 of the adhesive layer 13 was 1.0 cm. The length in the width direction of the adhesive layer 13 is 8.0 cm shorter than the width in the width direction of the protective film 14 and the distance between the end P3 of the adhesive layer 13 and the end P4 of the protective film 14 is 4.0 cm Respectively.

The obtained polarizing laminated film roll was provided on the rewinder to loosen the polarizing laminated film, but there was no blocking or the like, and it was possible to smoothly release the film even when it was unwound in the next step. Further, while both ends were slit with a laser beam to directly adhere the protective film and the base film through the adhesive layer, and the portion where the polarizer layer was not laminated was removed, but the slit blade was stable and the end was cleanly removed I could.

Further, the base film was peeled off from the polarizing laminated film obtained by slitting. Since the end portion is slit, the film can be smoothly peeled off, and a polarizing plate comprising a protective film / adhesive layer / polarizer layer / primer layer can be obtained.

[Comparative Example 1]

A primer layer and a resin layer were formed on the same base film as in Example 1, in the same manner as in Example 1. The uncoated portions of the end portions were slit-removed with a laser beam so that both ends of the resin layer and the substrate film coincided with each other. Thereafter, stretching, dyeing, crosslinking and drying were carried out in the same manner as in Example 1 to form a polarizer layer with a resin layer. The protective film used in Example 1 was adjusted to have the same width as that of the polarizer layer and the base film of the obtained laminated film and set on the side of the polarizer layer of the laminated film and the adhesive solution was fed between the two films and then bonded with a bonding roll. At this time, the feed amount of the adhesive solution was adjusted so that the adhesive layer spreads sufficiently evenly to the end portion of the polarizer layer. Thereafter, the film was dried at 80 DEG C for 5 minutes to obtain a long polarizing laminated film consisting of five layers of a base film / primer layer / polarizer layer / adhesive layer / protective film. The amount of the adhesive agent was continuously adjusted. However, the adhesive agent was slightly removed from the end of the film due to the sagging of the film or the fluctuation of the feed amount, and the adhesive agent adhered to the adhesive roll. As a result of flowing several tens of m of the film, the adhesive adhered to the backing roll (back surface opposite to the surface on the side of the polarizer layer) of the base film and the protective film began to adhere, and the backside contamination began to become noticeable.

As a result of measuring the position of the end of each layer in the cross section of the obtained polarizing laminated film, both ends of the base film, the polarizer layer, the adhesive layer and the protective film were at substantially the same positions. However, There was a portion of the film that was either inward or overflowed beyond the end of the film.

The resultant polarizing laminated film was again rolled up into a roll. The roll was released for the slit, but the film adhered to each other in the region near the end of the film by the adhesive flowing on the backside, and the adhesive layer was cohesively broken at the time of releasing, leaving white traces of cohesive failure. Also, the tension at the time of unwinding was not stabilized.

Furthermore, when the laser beam is slit in the next step, the slit blade does not enter uniformly due to the influence of the deformation of the end portion due to the poor release and the thickness of the adhesive layer at the end portion, . The end portion of the film obtained by the slit is in a state in which white powder is formed, and since the thickness is increased, a problem such as a high edge is generated when the film is wound.

Further, although the base film was peeled off from the obtained polarizing laminated film by slitting, it was not possible to smoothly peel off the base film due to irregularity at the end, and the end became jagged. Further, there is also a problem that the powder adheres to the back surface of the film. Furthermore, when the end portion was observed, there was a portion where the adhesive was not sufficient, and there was a defective portion where a gap was spread between the protective film and the polarizer layer.

Table 1 summarizes the polarizing laminated films of Examples 1 to 3 and Comparative Example 1 and summarizes the state of the end portions after bonding.

Base film The location of the end of each layer Backside contamination Next process Example 1 Multilayer PP (Outside) P1? P3? P2 (inside)
(Outer side) P4? P3? P2 (inner side) none Good Example 2 Polyester-based (Outside) P1? P3? P2 (inside)
(Outer side) P4? P3? P2 (inner side) none Good Comparative Example 1 Multilayer PP (Outer side) P1, P2, P3, P4 (inner side) has exist Loose defective
Slit failure
Bad adhesion of end

The polarizing laminated film of the present invention can be effectively applied to various display devices including a liquid crystal display device.

11: base film, 11a: uncoated portion, 12: resin layer (polarizer layer), 13: adhesive layer, 14: protective film.

Claims (6)

A polarizing laminated film having a long base film, a polarizer layer, an adhesive layer, and a protective film stacked in this order,
Wherein both ends of the polarizer layer are positioned inside both ends of the base film and the protective film in the width direction of the polarizing laminated film and both ends of the adhesive layer are located outside both ends of the polarizer layer, And a polarizing laminated film positioned inside both ends of the protective film. The polarizing laminated film according to claim 1, wherein the polarizer layer is a polyvinyl alcohol-based resin layer in which a dichroic dye is adsorbed and oriented, and the thickness is 10 占 퐉 or less. A polarizing laminated film roll in which the polarizing laminated film according to claim 1 is wound. A lamination step of forming a polyvinyl alcohol resin layer on at least one side of a long base film to obtain a laminated film,
A stretching step of uniaxially stretching the laminated film,
A dyeing step of staining the resin layer of the laminated film subjected to the uniaxial stretching with a dichroic dye;
A crosslinking step of immersing the resin layer of the laminated film subjected to the dyeing in a solution containing a crosslinking agent and crosslinking to form a polarizer layer;
And a bonding step of bonding a protective film to the surface of the polarizer layer opposite to the base film side of the laminated film that has undergone crosslinking through an adhesive layer in this order,
In the laminating step, portions where the polyvinyl alcohol-based resin layer is not formed are formed at both ends in the width direction of the base film,
In the joining step, both ends of the polarizer layer are positioned inside both ends of the protective film in the width direction of the laminated film after the joining, both ends of the adhesive layer are located outside both ends of the polarizer layer, Wherein the base film and the protective film are bonded to each other so as to be located on the inner side of both ends of the base film and the protective film. The method of producing a polarizing laminated film according to claim 4, further comprising a removing step of cutting off the portion of the laminated film directly bonded with the base film and the protective film through the adhesive layer after the bonding step . A method for producing a polarizing plate having a peeling step of peeling off the base film from a polarizing laminated film produced by the method according to claim 5.

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