JP6133792B2 - Polarizing laminated film and method for producing the same - Google Patents

Description

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

  A polarizing plate is widely used as a polarized light supplying element and a polarized light detecting element in a liquid crystal display device. As such a polarizing plate, a polarizing film made of polyvinyl alcohol resin and a protective film made of triacetyl cellulose are conventionally used. However, in recent years, mobile devices such as notebook personal computers and mobile phones for liquid crystal display devices have been used. Thinner and lighter weights are being demanded with the development of equipment and even with large televisions.

  As a method for producing such a thin polarizing plate, a solution containing a polyvinyl alcohol-based resin is applied to the surface of a base film to provide a resin layer, and then stretched and then dyed to have a polarizer layer. A method has been proposed in which a laminated film is obtained, and a protective film is bonded thereto to obtain a polarizing laminated film, and then a substrate film is peeled from the polarizing laminated film to obtain a polarizing plate (for example, a special film (See Kai 2000-338329).

JP 2000-338329 A

  When a protective film is bonded to a laminated film having a base film and a polarizer layer via an adhesive layer to obtain a polarizing laminated film, when a continuous lamination is performed using a bonding roll, There is a problem in that the adhesive overflows from the end of the polarizing laminated film, the laminating roll is contaminated, the adhesive gradually wraps around the back surface of the polarizing laminated film, and the film itself is also contaminated. When the laminated film is rolled up in such a state, there is a problem that blocking occurs due to the influence of the adhesive that has wrapped around the back surface of the laminated film, and a problem that the film cannot be stably unwound in the next step is likely 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 sufficiently reach the end of the polarizer and the adhesion at the end is not stable.

  The present invention is a long polarizing laminated film in which a base film, a polarizer layer, an adhesive layer, and a protective film are laminated in this order, and the polarizer layer and the protective film have a stable adhesive force. It aims at providing the manufacturing method of the polarizing laminated film which is pasted together and does not overflow of an adhesive agent, the polarizing laminated film roll formed by winding it, and a polarizing laminated film.

The present invention includes the following.
[1] A long polarizing laminate film in which a base film, a polarizer layer, an adhesive layer, and a protective film are laminated in this order, and in the width direction of the polarizing laminate film, Both ends are located inside both ends of the base film and the protective film, both ends of the adhesive layer are located outside both ends of the polarizer layer, and are located inside both ends of the base film and the protective film. Laminated film.
[2] The polarizing layer 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 μm or less.
[3] A polarizing laminated film roll around which the polarizing laminated film according to [1] is wound.
[4] A laminating step for forming a laminated film by forming a polyvinyl alcohol-based resin layer on at least one surface of the long base film, a stretching step for uniaxially stretching the laminated film, and uniaxial stretching were performed. A dyeing step of dyeing the resin layer of the laminated film with a dichroic dye; a crosslinking step of immersing the dyed laminated film resin layer in a solution containing a crosslinking agent to form a polarizer layer; and crosslinking. In this order, the laminating film has a laminating step for laminating a protective film on the surface opposite to the surface on the base film side of the polarizer layer in this order. The both ends of the base film in the width direction are provided with portions that do not form the polyvinyl alcohol-based resin layer, and in the bonding step, both ends of the polarizer layer are protected in the width direction of the laminated film after bonding. Both film Manufacture of a polarizing laminated film that is positioned so as to be located on the inner side of the edge and bonded so that both ends of the adhesive layer are located on the outer side of both ends of the polarizer layer and on the inner side of both ends of the base film and the protective film Method.
[5] After the above bonding step, in [4], including a removing step of cutting and removing a portion where the base film and the protective film are directly bonded via the adhesive layer from the polarizing laminated film. The manufacturing method of the polarizing laminated film of description.
[6] A method for producing a polarizing plate, comprising a peeling step of peeling and removing the base film from the polarizing laminated film produced by the method according to [5].

  According to the present invention, the polarizer layer and the protective film are bonded with a stable adhesive force, and it is possible to provide a polarizing laminated film that does not cause problems such as blocking during winding. A polarizing plate can be obtained from a polarizing laminated film.

It is a figure which shows typically the cross section of the width direction of the light-polarizing laminated film of this invention. It is a flowchart which shows the manufacturing method of the light-polarizing laminated film of this invention. It is an upper surface perspective view which shows typically the laminated film after each manufacturing process of the manufacturing method of the light-polarizing laminated film of this invention.

[Polarized laminated film]
FIG. 1 is a diagram schematically showing a cross-section in the width direction of the polarizing laminate film of the present invention. 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 of the base film 11 in the width direction are P1, both ends of the polarizer layer 12 in the width direction are P2, both ends of the adhesive layer 13 in the width direction are P3, and both ends of the protective film 14 in the width direction. Is P4, both ends P2 of the polarizer layer 12 are located inside both ends P1 of the base film 11 and both ends P4 of the protective film 14, and both ends P3 of the adhesive layer 13 are outside of both ends P2 of the polarizer layer 12. And located inside 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 with a stable adhesive force by the adhesive layer 13, and the adhesive overflows from the polarizing laminated film and contaminates the bonding roll. Does not cause problems such as

(Base film)
As the resin used for the base film 11, for example, thermoplastic resins having excellent transparency, mechanical strength, thermal stability, stretchability and the like are used, and depending on their glass transition temperature (Tg) or melting point (Tm). The appropriate resin can be selected. Specific examples of thermoplastic resins include polyolefin resins, polyester resins, cyclic polyolefin resins (norbornene resins), (meth) acrylic resins, cellulose ester resins, polycarbonate resins, polyvinyl alcohol resins, vinyl acetate. Resin, polyarylate resin, polystyrene resin, polyethersulfone resin, polysulfone resin, polyamide resin, polyimide resin, and mixtures and copolymers thereof.

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

  Examples of the polyolefin resin include polyethylene and polypropylene, which are preferable because they can be stably stretched at a high magnification. Further, an ethylene-polypropylene copolymer obtained by copolymerizing propylene with ethylene can also be used. Copolymerization can be performed with other types of monomers, and examples of other types of monomers copolymerizable with propylene include ethylene and α-olefins. 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 α-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, 4-methyl-1-pentene; vinylcyclohexane and the like. The copolymer of propylene and other monomers copolymerizable therewith may be a random copolymer or a block copolymer. The content of the structural unit derived from the other monomer in the copolymer is determined by infrared (IR) spectrum according to the method described on page 616 of “Polymer Analysis Handbook” (1995, published by Kinokuniya). It can be obtained by measuring.

  Among the above, propylene-based resins constituting the propylene-based resin film include propylene homopolymer, propylene-ethylene random copolymer, propylene-1-butene random copolymer, and propylene-ethylene-1-butene. Random copolymers are preferably used.

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

  The polyester resin is a polymer having an ester bond and is mainly a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. As the polyvalent carboxylic acid used, divalent dicarboxylic acids are mainly used, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalenedicarboxylate. In addition, divalent diol is mainly used as the polyhydric alcohol used, and examples thereof include propanediol, butanediol, neopentyl glycol, cyclohexanedimethanol and the like.

  A typical example of the polyester resin is polyethylene terephthalate which is a copolymer of terephthalic acid and ethylene glycol. Polyethylene terephthalate is a crystalline resin, but the one in a state before crystallization treatment is more easily subjected to treatment such as stretching. If necessary, it can be crystallized during stretching or by heat treatment after stretching. In addition, a copolymerized polyester whose crystallinity has been lowered (or made amorphous) by further copolymerizing another monomer with the polyethylene terephthalate skeleton is also preferably used. As examples of such resins, for example, those obtained by copolymerization of cyclohexanedimethanol, isophthalic acid or the like are preferably used. These resins are also excellent in stretchability and can be suitably used.

  Specific resins other than polyethylene terephthalate and copolymers thereof include polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexane dimethyl terephthalate, polycyclohexane dimethyl naphthalate. Phthalate, and the like. These blend resins and copolymers can also be suitably used.

  As the cyclic polyolefin resin, a norbornene resin is preferably used. Cyclic polyolefin resin is a general term for resins that are polymerized using cyclic olefin as a polymerization unit, and is described in, for example, JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, and the like. Resin. Specific examples include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, cyclic olefins and α-olefins such as ethylene and propylene (typically random copolymers), And graft polymers obtained by modifying them with an unsaturated carboxylic acid or a derivative thereof, and hydrides thereof. Specific examples of the cyclic olefin include norbornene monomers.

  Various products are commercially available as cyclic polyolefin resins. As specific examples, Topas (registered trademark) (manufactured by Ticona), Arton (registered trademark) (manufactured by JSR Corporation), ZEONOR (registered trademark) (manufactured by Nippon Zeon Corporation), ZEONEX (ZEONEX) (Registered trademark) (manufactured by ZEON CORPORATION) and Apel (registered trademark) (manufactured by Mitsui Chemicals, Inc.).

  Any appropriate (meth) acrylic resin can be adopted as the (meth) acrylic resin. For example, poly (meth) acrylic acid ester 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) acrylic acid methyl-styrene copolymer (MS resin, etc.), polymer having an alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl methacrylate copolymer) And methyl methacrylate- (meth) acrylate norbornyl copolymer). Preferably, C1-6 alkyl poly (meth) acrylates, such as poly (meth) acrylate methyl, are mentioned. More preferably, as the (meth) acrylic resin, a methyl methacrylate-based resin containing methyl methacrylate as a main component (50 to 100% by weight, preferably 70 to 100% by weight) is used.

  The cellulose ester resin is an ester of cellulose and a fatty acid. Specific examples of the cellulose ester resin include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. Moreover, these copolymers and those obtained by modifying a part of the hydroxyl group with other types of substituents are also included. Among these, cellulose triacetate is particularly preferable. Many products of cellulose triacetate are commercially available, which is advantageous in terms of availability and cost. Examples of commercially available products of cellulose triacetate include Fujitac (registered trademark) TD80 (manufactured by Fuji Film Co., Ltd.), Fujitac (registered trademark) TD80UF (manufactured by Fuji Film Co., Ltd.), Fujitac (registered trademark) TD80UZ (Fuji Film ( Co., Ltd.), Fujitac (registered trademark) TD40UZ (Fuji Film Co., Ltd.), KC8UX2M (Konica Minolta Opto Co., Ltd.), KC4UY (Konica Minolta Opto Co., Ltd.), and the like.

  The polycarbonate resin is an engineering plastic made of a polymer in which monomer units are bonded via a carbonate group, and is a resin having high impact resistance, heat resistance, and flame retardancy. Moreover, since it has high transparency, it is suitably used in optical applications. In optical applications, resins called modified polycarbonates in which the polymer skeleton is modified in order to lower the photoelastic coefficient, copolymerized polycarbonates with improved wavelength dependency, and the like are commercially available and can be suitably used.

  Such polycarbonate resins are widely commercially available. For example, Panlite (registered trademark) (Teijin Chemicals Ltd.), Iupilon (registered trademark) (Mitsubishi Engineering Plastics), SD Polyca (registered trademark) (Sumitomo) Dow Co., Ltd.), Caliber (registered trademark) (Dow Chemical Co., Ltd.) and the like.

  Arbitrary appropriate additives may be added to the base film 11 in addition to the thermoplastic resin. Examples of such additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, and coloring agents. . 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, and particularly preferably 70 to 97%. % By weight. This is because, if the content of the thermoplastic resin in the base film is less than 50% by weight, the high transparency inherent in the thermoplastic resin may not be sufficiently exhibited.

  Although the thickness of the base film 11 can be determined as appropriate, it is generally preferably 1 to 500 μm, more preferably 1 to 300 μm, and further preferably 5 to 200 μm from the viewpoint of workability such as strength and handleability. As for the thickness of a base film, 5-150 micrometers is the most preferable.

  The base film 11 may be subjected to corona treatment, plasma treatment, flame treatment, or the like on at least the surface on which the polarizer layer 12 is formed in order to improve the adhesion with the polarizer layer 12. Moreover, in order to improve adhesiveness, you may form thin layers, such as a primer layer and an adhesive bond layer, in the surface at the side in which the polarizer layer 12 of the base film 11 is formed. When providing a primer layer, it is preferable to form over the whole surface of the base film 11. In addition, the base film 11 here means what does not contain an adhesive bond layer, a corona treatment layer, etc.

(Polarizer layer)
The polarizer layer 12 is formed by dyeing a polyvinyl alcohol-based resin layer with a dichroic dye, and preferably has a thickness of 10 μm or less. The polyvinyl alcohol-based resin used for the polarizer layer 12 is preferably a modified polyvinyl alcohol having a saponification degree of 90 to 100 mol% and partially modified. For example, polyvinyl alcohol resin modified with olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, alkyl esters of unsaturated carboxylic acid, acrylamide, and the like by several percent. The average degree of polymerization of the polyvinyl alcohol-based resin is not particularly limited, but is preferably 100 to 10,000, and more preferably 1500 to 10,000.

  Examples of the polyvinyl alcohol-based resin that gives such characteristics include PVA124 (degree of saponification: 98.0 to 99.0 mol%) and PVA117 (degree of saponification: 98.0 to 99.0) manufactured by Kuraray Co., Ltd. Mol%), PVA624 (degree of saponification: 95.0-96.0 mol%), PVA617 (degree of saponification: 94.5-95.5 mol%), etc .; for example, AH manufactured by Nippon Synthetic Chemical Industry Co., Ltd. -26 (degree of saponification: 97.0 to 98.8 mol%), AH-22 (degree of saponification: 97.5 to 98.5 mol%), NH-18 (degree of saponification: 98.0 to 99) 0.0 mol%), N-300 (degree of saponification: 98.0 to 99.0 mol%), etc .; for example, JF-17 (degree of saponification: 98.0 to 99.9) of Nippon Vinegar Pival Co., Ltd. 0 mol%), JF-17L (degree of saponification: 98.0-99.0 mol%), JF 20 (saponification degree: 98.0 to 99.0 mol%), etc. can be suitably used include.

(Protective film)
The protective film 14 may be a simple protective film having no optical function, or may be a protective film having an optical function such as a retardation film or a brightness enhancement film. The material of the protective film 14 is not particularly limited. For example, a cyclic polyolefin resin film, a cellulose acetate resin film made of a resin such as triacetyl cellulose or diacetyl cellulose, polyethylene terephthalate, polyethylene naphthalate, Examples thereof include films that have been widely used in the art, such as polyester resin films, polycarbonate resin films, acrylic resin films, and polypropylene resin films made of a resin such as polybutylene terephthalate.

  Examples of the cyclic polyolefin-based resin include appropriate commercial products such as Topas (registered trademark) (manufactured by Ticona), Arton (registered trademark) (manufactured by JSR Corporation), ZEONOR (registered trademark) (Nippon ZEON ( ZEONEX (registered trademark) (manufactured by Nippon Zeon Co., Ltd.), Apel (registered trademark) (manufactured by Mitsui Chemicals, Inc.) can be suitably used. When such a cyclic polyolefin resin is formed into a film, a known method such as a solvent casting method or a melt extrusion method is appropriately used. In addition, pre-filmed cyclic polyolefins such as Essina (registered trademark) (manufactured by Sekisui Chemical Co., Ltd.), SCA40 (manufactured by Sekisui Chemical Co., Ltd.), Zeonoa (registered trademark) film (manufactured by Optes Co., Ltd.), etc. A commercial product of a film made of a resin may be used.

  The cyclic polyolefin resin film may be uniaxially stretched or biaxially stretched. An arbitrary retardation value can be imparted to the cyclic polyolefin-based resin film by stretching. Stretching is usually performed continuously while unwinding the film roll, and is stretched in the heating furnace in the roll traveling direction, the direction perpendicular to the traveling direction, or both. The temperature of the heating furnace is usually in the range from the vicinity of the glass transition temperature of the cyclic polyolefin resin to the glass transition temperature + 100 ° C. The draw ratio is usually 1.1 to 6 times, preferably 1.1 to 3.5 times in one direction.

  Since the cyclic polyolefin resin film generally has poor surface activity, the surface to be bonded to the polarizer layer is subjected to surface treatment such as plasma treatment, corona treatment, ultraviolet irradiation treatment, flame (flame) treatment, saponification treatment, etc. Is preferred. Among these, plasma treatment and corona treatment that can be performed relatively easily are preferable.

  Examples of the cellulose acetate-based resin film include commercially available products such as Fujitac (registered trademark) TD80 (manufactured by Fuji Film Co., Ltd.), Fujitac (registered trademark) TD80UF (manufactured by Fuji Film Co., Ltd.), and Fujitac (registered trademark). TD80UZ (Fuji Film Co., Ltd.), Fujitac (registered trademark) TD40UZ (Fuji Film Co., Ltd.), KC8UX2M (Konica Minolta Opto Co., Ltd.), KC4UY (Konica Minolta Opto Co., Ltd.) are preferably used. be able to.

  A liquid crystal layer or the like may be formed on the surface of the cellulose acetate-based resin film in order to improve viewing angle characteristics. Moreover, in order to provide a phase difference, what stretched the cellulose acetate type-resin film may be used. The cellulose acetate-based resin film is usually subjected to a saponification treatment in order to improve the adhesiveness with the polarizing film. As the saponification treatment, a method of immersing in an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide can be employed.

  An optical layer such as a hard coat layer, an antiglare layer, or an antireflection layer can be formed on the surface of the protective film 14 as described above. The method for forming these optical layers 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, preferably 88 μm or less, and more preferably 48 μm or less, from the demand for thinning. If it is too thin, the strength is lowered and the processability is poor, and therefore it is preferably 5 μm or more.

(Adhesive layer)
The adhesive used for forming the adhesive layer 13 for bonding the protective film 14 and the polarizer layer 12 is, for example, an aqueous adhesive using a polyvinyl alcohol-based resin aqueous solution, an aqueous two-component urethane emulsion adhesive, or the like. Is mentioned. When using the cellulose acetate type-resin film hydrophilized by the saponification process etc. as the protective film 14, a polyvinyl alcohol-type resin aqueous solution is used suitably as a water-based adhesive for bonding with the polarizer layer 12. FIG. Polyvinyl alcohol resins used as adhesives include vinyl alcohol homopolymers obtained by saponifying polyvinyl acetate, which is a homopolymer of vinyl acetate, as well as other single quantities copolymerizable with vinyl acetate. And vinyl alcohol copolymers obtained by saponifying the copolymer with the polymer, and modified polyvinyl alcohol polymers obtained by partially modifying the hydroxyl groups. A polyhydric aldehyde, a water-soluble epoxy compound, a melamine compound, a zirconia compound, a zinc compound, or the like may be added as an additive to the water-based adhesive.

  Moreover, a photocurable adhesive can also be used as an adhesive at the time of bonding the polarizer layer 12 and the protective film 14. Here, the photocurable adhesive is an adhesive that is cured by irradiating active energy rays such as ultraviolet rays. For example, the adhesive includes a polymerizable compound and a photopolymerization initiator, and includes a photoreactive resin. And those containing a binder resin and a photoreactive cross-linking agent. 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 containing substances that generate active species such as neutral radicals, anion radicals, and cation radicals by irradiation with active energy rays such as ultraviolet rays. As a photocurable adhesive containing a polymerizable compound and a photopolymerization initiator, those containing a photocurable epoxy monomer and a photocationic polymerization initiator are preferable.

[Polarizing laminated film roll]
The polarizing laminated film roll of the present invention is produced by winding the long laminated film. Since the polarizing laminated film roll of the present invention does not overflow the adhesive from the laminated film, blocking caused by the overflowing adhesive can be suppressed.

[Method for producing polarizing laminated film]
FIG. 2 is a flowchart showing a method for producing a polarizing laminate film of the present invention. FIG. 3 is a top perspective view schematically showing the laminated film after each production step in the method for producing a polarizing laminated film of the present invention. The production method of the present invention includes a lamination step (S10) in which a polyvinyl alcohol-based resin layer 12 is formed on at least one surface of a long base film 11 to obtain a laminated film, and a stretching step in which the laminated film is uniaxially stretched. (S20), a dyeing step (S30) for dyeing a resin layer of a laminated film subjected to uniaxial stretching with a dichroic dye, and a resin layer of the dyed laminated film are immersed in a solution containing a crosslinking agent. A cross-linking step (S40) for cross-linking to form a polarizer layer, and a protective film 14 is pasted on the surface of the cross-linked laminated film opposite to the surface on the base film side of the polarizer layer via an adhesive layer. It is the manufacturing method of the polarizing laminated film which has the bonding process (S50) to combine in this order. In a bonding process (S50), Preferably, it carries out sending bonding so that a laminated | multilayer film and the protective film 14 may overlap between a 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), and the region outside the dotted line P2 The portion 11a where the polyvinyl alcohol-based resin layer is not formed is provided. As a method for forming such a resin layer 12, for example, a solution containing a polyvinyl alcohol-based resin is not applied to a region outside the dotted line P2 in the base film 11, and only a region inside the dotted line P2 is polyvinyl alcohol-based. The method of drying after apply | coating the solution containing resin is mentioned. Thus, by providing the part (unapplied part) 11a in which the resin layer 12 is not formed, even if the adhesive is sufficiently fed to the end of the polarizer layer in the bonding step (S50), the back of the adhesive Therefore, a good polarizing laminate film can be obtained. In addition, by providing the uncoated portion 11a, it is possible to suppress a phenomenon in which both ends of the base film 11 warp on the coated surface side of the solution containing the resin when the laminated film is dried. The dotted line P2 that defines the uncoated portion 11a is determined within a region that is preferably 0.5 cm or more, more preferably 1 cm or more, and even more preferably 2 cm or more from both ends of the base film 11 in the width direction. By setting it as such a numerical value range, the effect which prevents the surroundings of the adhesive to the back surface can be acquired more reliably. Further, the position of the dotted line P2 is preferably within a region of 50 cm or less from both ends in the width direction of the base film 11, more preferably within a region of 30 cm or less, and within a region of 20 cm or less. Further preferred.

  Further, in the bonding step (S50), as shown in FIG. 3 (c), the adhesive layer is applied to the dotted line P3 that is outside the both ends in the width direction of the polarizer layer 12 so as to cover the entire polarizer layer 12. The protective film 14 is bonded through the adhesive layer. The dotted line P3 that defines the region of the adhesive layer can be determined outward from both ends of the polarizer layer, for example, within a region 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 coating amount of the adhesive, the applied pressure by the pressure bonding device (the distance between the bonding rolls when a bonding roll is used), the film What is necessary is just to adjust the conveyance speed of this. In addition, when continuous bonding is performed with a long film, an adhesive is continuously supplied between the films, while an excess amount overflows from the widthwise end of the film laminated through the adhesive layer. The bonding step (S50) can be carried out while continuously sucking the adhesive using a suction device. In this case, the width of the adhesive layer can also be adjusted by adjusting the suction amount of the adhesive. Can do.

  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, and the entire adhesive layer is covered with the protective film 14. That is, in the width direction of the laminated film after pasting, both ends of the polarizer layer are positioned inside both ends of the protective film, both ends of the adhesive layer are positioned outside both ends of the polarizer layer, and the base film And it bonds so that it may be located inside the both ends of a protective film. The protective film 14 is not limited as long as the length in the width direction is longer than the length in the width direction of the adhesive layer, but is preferably 0.5 cm or more, more preferably 1 cm than the length in the width direction of the polarizer layer. As described above, a material longer by 2 cm or more is selected.

  According to the production method of the present invention, in the bonding step (S50), since the entire polarizer layer is covered with the adhesive layer, the polarizer layer and the protective film are bonded with a stable adhesive force. The adhesive layer is provided such that both ends in the width direction are located inside the both ends of the base film and the protective film, so there is no overflow of the adhesive, such as an adhesive laminating roll and a polarizing laminated film, etc. Contamination can be prevented.

  The polarizing laminated film manufactured through the above steps is preferably wound to constitute a polarizing laminated film roll. In the polarizing laminated film, since contamination with the adhesive is suppressed, it is possible to prevent the occurrence of blocking when it is wound, and thus inconveniences such as difficulty in unwinding in the subsequent steps. There is no.

  After the bonding step (S50), the polarizing laminated film is cut at the same position as the both ends of the polarizer layer 12 or slightly inside the both ends of the polarizer layer 12 to remove the end portions, and the base film is further removed. You may have the peeling process to peel. The film obtained by the peeling step can be used as a polarizing plate. For the cutting of the polarizing laminated film, a method capable of continuously treating a long length such as a roll is preferable. Although it does not specifically limit as a method, For example, the method generally called the slitter etc. can be used suitably.

  As an example of the slitter, for example, there is a method using a razor blade called a leather blade. Even with the method using the same leather blade, there is a hollow cut that slits in the air without providing a backup guide, and a groove roll method that stabilizes the meandering of the slit by inserting the blade into a roll with a groove as a backup guide is there. In addition, two circular blades called shear blades are used for slitting by applying contact pressure to the lower blade with the upper blade while rotating according to the film transport, and blades called shear blades and score blades A method of slitting by pressing it against a quenching roll or the like, and further, a method of slitting while cutting like scissors by combining two shear blades. Among them, the “groove roll method using a leather blade”, which is a method that can easily change the slit position of the film and is easy to travel, is preferably used.

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

[Resin Layer Forming Step (S10)]
Here, a laminated film is obtained by forming a polyvinyl alcohol-based resin layer on at least one surface of the base film. Examples of the method for forming the resin layer include a method in which a solution containing a polyvinyl alcohol-based resin is applied to at least one surface of a base film and then dried. Materials suitable for the base film and the polyvinyl alcohol-based resin are as described in the explanation of the polarizing laminated film. It is preferable to use a base film that can be 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 μm and not more than 30 μm, more preferably 5 to 20 μm. If it is 3 μm or less, it becomes too thin after stretching and the dyeability is remarkably deteriorated. If it exceeds 30 μm, the thickness of the finally obtained polarizer layer may exceed 10 μm, which is not preferable.

  The resin layer is preferably formed by applying a polyvinyl alcohol resin solution obtained by dissolving polyvinyl alcohol resin powder in a good solvent onto one surface of the base film, and evaporating the solvent to dry the resin layer. It is formed. By forming the resin layer in this way, it can be formed thin. As a method of applying a polyvinyl alcohol resin solution to a base film, a wire bar coating method, a reverse coating, a roll coating method such as gravure coating, a die coating method, a comma coating method, a lip coating method, a spin coating method, a screen coating method. A method, a fountain coating method, a dipping method, a spray method, and the like can be appropriately selected from known methods and employed. A drying temperature is 50-200 degreeC, for example, Preferably it is 60-150 degreeC. The drying time is, for example, 2 to 20 minutes.

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

[Stretching step (S20)]
Here, the laminated film consisting of the base film and the resin layer is uniaxially stretched. Preferably, uniaxial stretching is performed so that the stretching ratio is more than 5 times and not more than 17 times. More preferably, it is uniaxially stretched so that the stretch ratio is more than 5 times and not more than 8 times. When the draw ratio is 5 times or less, the resin layer made of the polyvinyl alcohol-based resin is not sufficiently oriented, and as a result, the degree of polarization of the polarizer layer may not be sufficiently high. On the other hand, if the draw ratio exceeds 17 times, the laminated film is likely to break during stretching, and at the same time, the thickness of the stretched film becomes unnecessarily thin, and the workability and handling properties in the subsequent process may be reduced. The stretching process in the stretching step (S20) is not limited to one-stage stretching, and can be performed in multiple stages. In this case, the second and subsequent stretching processes may be performed in the stretching process (S20), but may be performed simultaneously with the processes in the dyeing process (S30) and the crosslinking process (S40). Thus, when extending | stretching by multistage, extending | stretching process is performed so that it may become a draw ratio exceeding 5 times combining all the stages of extending | stretching process.

  In the stretching step (S20), a longitudinal stretching process performed in the longitudinal direction of the laminated film, a lateral stretching process stretching in the width direction, or the like can be performed. Examples of the longitudinal stretching method include an inter-roll stretching method and a compression stretching method, and examples of the transverse stretching method include a tenter method.

  In addition, as the stretching treatment, either a wet stretching method or a dry stretching method can be adopted, but the use of the dry stretching method is preferable because the temperature at which the laminated film is stretched can be selected from a wide range.

[Dyeing step (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 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, Spura Blue G, Spura Blue GL, Spura Orange GL, Direct Sky Blue, Direct First Orange S, First Black, etc. can be used. One kind of these dichroic substances may be used, or two or more kinds may be used in combination.

  A dyeing process is performed by immersing the whole laminated film in a solution (dyeing solution) containing the above-mentioned dichroic dye, for example. As the staining solution, a solution in which the above dichroic dye is dissolved in a solvent can be used. As a solvent for the dyeing solution, water is generally used, but an organic solvent compatible 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 an 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 iodide. Examples include titanium. The addition ratio of these iodides is preferably 0.01 to 20% by weight in the dyeing solution. Of the iodides, it is preferable to add potassium iodide. When potassium iodide is added, the ratio of iodine to potassium iodide is preferably in the range of 1: 5 to 1: 100, more preferably in the range of 1: 6 to 1:80 by weight. , Particularly preferably in the range of 1: 7 to 1:70.

  The immersion time of the laminated film in the dyeing solution is not particularly limited, but it is usually preferably in the range of 15 seconds to 15 minutes, more preferably 30 seconds to 3 minutes. Moreover, it is preferable that it is in the range of 10-60 degreeC, and, as for the temperature of a dyeing | staining solution, it is more preferable that it exists in the range of 20-40 degreeC.

  Although the dyeing treatment can be performed before or simultaneously with the stretching step, the unstretched film is subjected to the stretching step so that the dichroic dye adsorbed on the polyvinyl alcohol-based resin can be favorably oriented. It is preferable to carry out after this. At this time, it may be simply dyed what has been previously stretched at a target magnification, or may be a method in which a stretch previously stretched at a low magnification is re-stretched during dyeing to reach the target magnification in total. good. Further, when the stretching is performed during the subsequent crosslinking treatment, the stretching can be limited to a low magnification. In this case, adjustment may be made in a timely manner so as to reach the desired magnification after the crosslinking treatment.

[Crosslinking step (S40)]
Following the dyeing step (S30), the crosslinking step (S40) is performed. The crosslinking step can be performed, for example, by immersing the laminated film that has undergone the dyeing step (S30) in a solution containing a crosslinking agent (crosslinking solution). Conventionally known substances can be used as the crosslinking agent. Examples thereof include boron compounds such as boric acid and borax, glyoxal, and glutaraldehyde. One kind of these may be used, or two or more kinds may be used in combination.

  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 can be used, but an organic solvent compatible with water may be further included. Although the density | concentration of the crosslinking agent in a crosslinking solution is not limited to this, It is preferable to exist in the range of 1-20 weight%, and it is more preferable that it is 6-15 weight%.

  Iodide may be added to the crosslinking solution. By adding iodide, the in-plane polarization characteristics 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. Is mentioned. The iodide content is 0.05 to 15% by weight, more preferably 0.5 to 8% by weight.

  The immersion time of the laminated film in the crosslinking solution is usually preferably from 15 seconds to 20 minutes, and more preferably from 30 seconds to 15 minutes. Moreover, it is preferable that the temperature of a crosslinking solution exists in the range of 10-90 degreeC.

  In addition, a crosslinking process can also be performed simultaneously with a dyeing process by mix | blending a crosslinking agent in a dyeing solution. Moreover, what was previously extended | stretched by the target magnification may be only bridge | crosslinked, and you may perform a bridge | crosslinking process and an extending | stretching process simultaneously. You may make it reach | attain the target magnification in total by extending | stretching the stretched film previously extended | stretched by the low magnification by the extending | stretching process again during a crosslinking process.

  It is preferable to perform a washing step after the crosslinking step. As the washing step, a water washing treatment can be performed. The water washing treatment can usually be performed by immersing the stretched film in pure water such as ion exchange water or distilled water. The water washing temperature is usually in the range of 3 to 50 ° C, preferably 4 to 20 ° C. The immersion time is usually 2 to 300 seconds, preferably 3 to 240 seconds.

  In the washing step, washing treatment with an iodide solution and water washing treatment may be combined, and a solution in which liquid alcohol such as methanol, ethanol, isopropyl alcohol, butanol, propanol or the like is appropriately blended may be used. Through the above steps, the resin layer has a function as a polarizer. In this specification, a resin layer having a function as a polarizer is referred to as a polarizer layer.

[Bonding process (S50)]
Here, a protective film is bonded to the surface of the polarizer layer opposite to the surface on the base film side through an adhesive layer to obtain a polarizing laminated film. Suitable materials for the protective film are as described in the explanation of the polarizing laminated film. Moreover, the material suitable for the adhesive is also as described in the description of the polarizing laminated film. For example, a water-based adhesive or a photo-curable adhesive can be used.

  The method of laminating the polarizer layer and the protective film using the water-based adhesive is not particularly limited. For example, the adhesive is uniformly applied to the surface of the polarizer layer and / or the protective film, and then applied to the coated surface. Examples include a method of stacking the other film and pasting with a pasting roll or the like. As a method of applying the adhesive to the surface of the polarizer layer and / or the protective film, for example, the tip of an adhesive feed nozzle is disposed between the polarizer layer and the protective film, and the nozzle is removed from the nozzle using a pump or the like. Surface of the polarizer layer and / or protective film by the method of supplying adhesive, casting method, Meyer bar coating method, gravure coating method, comma coater method, doctor plate method, die coating method, dip coating method, spraying method, etc. The method of apply | coating an adhesive agent etc. can be mentioned.

  When using an aqueous adhesive, after laminating the polarizer layer and the protective film, the laminated film is dried in order to remove water contained in the aqueous adhesive. The temperature of the drying furnace is preferably 30 to 90 ° C. When the temperature is lower than 30 ° C., the polarizer layer surface and the protective film surface tend to be easily peeled off. If it is 90 ° C. or higher, the optical performance may be deteriorated by heat. The drying time can be 10 to 1000 seconds, and from the viewpoint of productivity, it is preferably 60 to 750 seconds, and more preferably 150 to 600 seconds.

  After drying, it may be further cured at room temperature or slightly higher temperature, for example, at a temperature of about 20 to 45 ° C. 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 of bonding the polarizer layer and the protective film with a photocurable adhesive, a conventionally known method can be used, for example, a casting method, a Mayer bar coating method, a gravure coating method, a comma coater method, Examples include a method of applying an adhesive on the adhesive surface of the polarizer layer and / or the protective film and superimposing the two by a doctor plate method, a die coating method, a dip coating method, a spraying method, or the like. The casting method is a method in which a polarizing film or a protective film, which is an object to be coated, is moved in a substantially vertical direction, a substantially horizontal direction, or an oblique direction between the two, and an adhesive is allowed to flow down and spread on the surface. It is.

  After the adhesive is applied to the surface of the polarizer layer or the protective film, the polarizing film and the protective film are bonded together by being sandwiched by a nip roll or the like through the adhesive application surface. In addition, there is a method in which an adhesive is dropped between the polarizer layer and the protective film in a state where the polarizer layer and the protective film are partially overlapped, and then this laminated film is pressed with a roll or the like to be uniformly spread. It can be preferably used. In this case, a metal, rubber, or the like can be used as the material of the roll. Furthermore, after dropping an adhesive agent between a polarizer layer and a protective film, the method of passing this laminated film between rolls and pressing and spreading it is also preferably employed. In this case, these rolls may be made of the same material or different materials. The thickness of the adhesive layer after being bonded using the nip roll or the like before drying or curing is preferably 5 μm or less and 0.01 μm or more.

  In order to improve adhesion, the surface of the polarizer layer and / or the protective film may be appropriately subjected to surface treatment such as plasma treatment, corona treatment, ultraviolet irradiation treatment, flame (flame) treatment, saponification treatment, etc. Good. Examples of the saponification treatment include a method of immersing in an aqueous alkali solution such as sodium hydroxide or potassium hydroxide.

  When a photocurable resin is used as an adhesive, the photocurable adhesive is cured by irradiating an active energy ray after joining the polarizing film and the protective film. The light source of the 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, the low-pressure mercury lamp, the medium-pressure mercury lamp, the high-pressure mercury lamp, the ultrahigh-pressure mercury lamp, the chemical lamp, and the black light lamp A microwave excitation mercury lamp, a metal halide lamp and the like are preferably used.

The light irradiation intensity to the photocurable adhesive is appropriately determined depending on the composition of the photocurable adhesive and is not particularly limited, but the irradiation intensity in the wavelength region effective for activating the polymerization initiator is 0.1 to 6000 mW / it is preferable that the cm ^2. When the irradiation intensity is 0.1 mW / cm ² or more, the reaction time does not become too long, and when it is 6000 mW / cm ² or less, the epoxy is generated by the heat radiated from the light source and the heat generated when the photo-curable adhesive is cured. There is little risk of yellowing of the resin or deterioration of the polarizing film. The light irradiation time to the photocurable adhesive is not particularly limited and is applied according to the photocurable adhesive to be cured, but the integrated light amount expressed as the product of the irradiation intensity and the irradiation time. Is preferably set to be 10 to 10,000 mJ / cm ² . When the cumulative amount of light to the photocurable adhesive is 10 mJ / cm ² or more, a sufficient amount of active species derived from the polymerization initiator can be generated to allow the curing reaction to proceed more reliably, and at 10,000 mJ / cm ² or less. In some cases, irradiation time does not become too long and good productivity can be maintained. The thickness of the adhesive layer after irradiation with active energy rays is usually about 0.001 to 5 μm, preferably 0.01 μm or more and 2 μm or less, more preferably 0.01 μm or more and 1 μm or less.

  When curing a photo-curable adhesive by irradiation with active energy rays, it may be cured under conditions that do not deteriorate the functions of the polarizing plate, such as the degree of polarization of the polarizing film, the transmittance and hue, and the transparency of the protective film. preferable.

[Peeling process]
In the manufacturing method of this invention, the peeling process of a base film can be performed after the bonding process (S50) which bonds a protective film to a polarizer layer. In the base film peeling step, the base film is peeled from the laminated film. The peeling method of a base film is not specifically limited, It can peel by the method similar to the peeling process of the peeling film performed with a normal polarizing plate with an adhesive. After the bonding step (S50), it may be peeled off as it is, or after it is wound up into a roll once, it may be peeled off by providing a separate peeling step.

[Example 1]
(1) Production of base film On both sides of a resin layer comprising a random copolymer of propylene / ethylene containing about 5% by weight of an ethylene unit (“Sumitomo Noblen W151” manufactured by Sumitomo Chemical Co., Ltd., melting point Tm = 138 ° C.) A base film roll having a three-layer structure in which a homopropylene propylene homopolymer (“Sumitomo Nobrene FLX80E4” manufactured by Sumitomo Chemical Co., Ltd., melting point Tm = 163 ° C.) is disposed is used as a multilayer extruder. It was produced by the coextrusion molding used. The total thickness of the obtained base film roll was 100 μm, 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 95 ° C. hot water, A polyvinyl alcohol aqueous solution having a concentration of 3% by weight was prepared. The resulting aqueous solution was mixed with 5 parts by weight of a crosslinking agent (“SUMIREZ RESIN 650” manufactured by Sumitomo Chemical Co., Ltd.) with respect to 6 parts by weight of polyvinyl alcohol powder. The obtained mixed aqueous solution is continuously coated on the corona-treated surface of the base film roll subjected to the corona treatment by using a gravure coater, and dried at 80 ° C. for 10 minutes to obtain a primer having a thickness of 0.2 μm. A layer was formed, and a film composed of a primer layer / substrate film was prepared. At this time, the primer layer was formed over the entire width of the base film.

(3) Laminating step Polyvinyl alcohol powder (“PVA124” manufactured by Kuraray Co., Ltd., average polymerization degree 2400, average saponification degree 98.0 to 99.0 mol%) is dissolved in hot water at 95 ° C., and the concentration is 8 weight. % Aqueous polyvinyl alcohol solution was prepared. From the base film / primer layer / polyvinyl alcohol resin layer, the obtained aqueous solution was continuously applied onto one primer layer of the base film using a comma coater and dried at 80 ° C. for 5 minutes. A laminated film roll having a three-layer structure was prepared. The thickness of the resin layer made of a polyvinyl alcohol resin was 10.6 μm. At the time of coating, a polyvinyl alcohol aqueous solution was not applied to areas within 3.0 cm from both ends of the base film, respectively, and an uncoated portion was formed. That is, the length in the width direction of the resin layer was 6 cm shorter than the length in the width direction of the base film.

(4) Stretching Step The above laminated film was wound in the longitudinal direction at a stretching temperature of 160 ° C. at a stretching temperature of 160 ° C. in the longitudinal direction 4.3 times in the free direction and then wound to obtain a laminated film roll. The thickness of the obtained laminated film was 55.2 μm, and the thickness of the polyvinyl alcohol resin layer was 6.3 μm.

(5) Dyeing process, crosslinking process About the laminated | multilayer film roll after extending | stretching, the dyeing process and the crosslinking process were performed in the following procedure. First, the laminated film is immersed in a dyeing solution at 30 ° C., which is an aqueous solution containing 30 ° C. iodine and potassium iodide, for a residence time of about 150 seconds, and the polyvinyl alcohol resin layer is dyed (dyeing step). Then, the excess iodine solution was washed away with pure water at 10 ° C. Next, it was immersed in a crosslinking solution at 72 ° C., which is an aqueous solution containing boric acid and potassium iodide, for a residence time of about 600 seconds (crosslinking step), thereby forming a polarizer layer from the resin layer. Then, after wash | cleaning for 4 second with a 10 degreeC pure water, it was made to dry at 80 degreeC for 300 second, and the laminated | multilayer film roll was obtained.

(6) Bonding Step First, polyvinyl alcohol powder (“KL-318” manufactured by Kuraray Co., Ltd., average polymerization degree 1800) was dissolved in hot water at 95 ° C. to prepare an aqueous polyvinyl alcohol solution having a concentration of 3% by weight. The resulting aqueous solution was mixed with 1 part by weight of a crosslinking agent (“SUMIREZ RESIN 650” manufactured by Sumitomo Chemical Co., Ltd.) with respect to 2 parts by weight of polyvinyl alcohol powder to obtain an adhesive solution.

  Next, a protective film made of triacetyl cellulose (TAC) having a width of 8.0 cm wider than the width of the polarizer layer (“KC4UY” manufactured by Konica Minolta Opto Co., Ltd.) is provided on the surface of the obtained laminated film on the polarizer layer side. ) Were set to be outside of the 4.0 cm polarizer layer at both ends, and the above adhesive solution was fed between both films, and then bonded together with a bonding roll. At this time, the feed amount of the adhesive solution was adjusted so that both ends in the width direction of the adhesive layer were outside of both ends of the polarizer layer and inside of both ends of the protective film and the base film. Then, it was made to dry at 80 degreeC for 5 minute (s), the polarizing laminated film was obtained, this was wound, and the polarizing laminated film roll was obtained. The obtained polarizing laminated film was a long polarizing laminated film comprising 5 layers of base film / primer layer / polarizer layer / adhesive layer / protective film.

  The obtained polarizing laminated film was in a good state since there was no overflow of the adhesive and therefore no leakage of the adhesive to the surface of the polarizing laminated film.

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

  Although the obtained polarizing laminated film roll was installed in a rewinder and the polarizing laminated film was unwound, there was no blocking or the like, and it was able to be smoothly unwound during unwinding in the next step. In addition, while continuously unwinding, both ends were slit with a laser blade, the protective film and the base film were directly bonded via the adhesive layer, and the part where the polarizer layer was not laminated was removed. The blade was also stable and the edges could be removed neatly.

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

[Example 2]
As a base material, a polyester base material (Teijin Limited: PETG) obtained by copolymerization of three monomers of 1,4 cyclohexanedimethanol, terephthalic acid, and ethylene glycol was used. The thickness of the base film was 70 μm. A primer layer and a polyvinyl alcohol-based resin layer were provided in the same manner as in Example 1 to prepare a laminated film having a structure of base film / primer layer / polyvinyl alcohol-based resin layer (laminating step). The thickness of the primer layer was 0.2 μm, and the thickness of the polyvinyl alcohol-based resin layer was 10.4 μm. Here, the polyvinyl alcohol aqueous solution was not applied to the region of both end portions within 3.0 cm from the end of the base film, and an uncoated portion was provided.

  The above laminated film was uniaxially stretched 4.0 times in the longitudinal direction at a stretching temperature of 110 ° C. by an inter-roll air stretching device (stretching step) to obtain a laminated film roll. The thickness of the obtained laminated film roll was 40.5 μm, and the thickness of the polyvinyl alcohol-based resin layer was 6.2 μm.

  The obtained laminated film was dyed in the same manner as in Example 1, washed and dried to obtain a laminated film. A protective film is bonded to the obtained laminated film in the same manner as in Example 1 (bonding step), and is a long film composed of five layers of base film / primer layer / polarizer layer / adhesive layer / protective film. A polarizing laminate film was obtained.

  The cross section in the width direction of the obtained polarizing laminated film was a cross section as shown in FIG. The length in the width direction of the adhesive layer 13 is 3.0 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 is 1.5 cm. It was. The length in the width direction of the polarizer layer 12 is 2.0 cm shorter 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 is 1.0 cm. It was. The length of the adhesive layer 13 in the width direction is 8.0 cm shorter than the length of the protective film 14 in the width direction, 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. It was.

  Although the obtained polarizing laminated film roll was installed in a rewinder and the polarizing laminated film was unwound, there was no blocking or the like, and it was able to be smoothly unwound during unwinding in the next step. In addition, while continuously unwinding, both ends were slit with a laser blade, the protective film and the base film were directly bonded via the adhesive layer, and the part where the polarizer layer was not laminated was removed. The blade was also stable and the edges could be removed neatly.

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

[Comparative Example 1]
On the same base film as in Example 1, a primer layer and a resin layer were formed in the same manner as in Example 1. The uncoated portion at the end was slit removed with a laser blade so that both ends of the resin layer and the base film coincided. Thereafter, stretching, dyeing, crosslinking, and drying were performed in the same manner as in Example 1 to form a polarizer layer from the resin layer. The protective film used in Example 1 was adjusted to the same width as the polarizer layer and the base film of the obtained laminated film, and this was set on the polarizer layer side of the laminated film, and an adhesive solution between both films. After being fed, it was pasted with a pasting roll. At this time, the feed amount of the adhesive solution was adjusted so that the adhesive layer sufficiently reached the end of the polarizer layer. Then, it was made to dry at 80 degreeC for 5 minute (s), and the elongate polarizing laminated film which consists of 5 layers of base film / primer layer / polarizer layer / adhesive layer / protective film was obtained. Although the feed amount of the adhesive was continuously adjusted, the adhesive protruded slightly from the end of the film and adhered to the bonding roll due to the meandering of the film and fluctuation of the feed amount. When a film of several tens of meters was poured, the adhesive attached to the laminating roll started to adhere to the back surface of the base film and the protective film (the surface opposite to the surface on the polarizer layer side), and the stain on the back surface was noticeable I started.

  When the position of the end of each layer was measured 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 substantially the same position, but the end of the adhesive layer There was a fluctuation in the position of, and there were some parts that entered the inside of the film edge and overflowed outside.

  The obtained polarizing laminated film was further wound into a roll. Although this roll was unwound for the slit, the adhesive stuck around the back side stuck the film in the area near the edge of the film, and the cohesive failure of the adhesive layer occurred during unwinding and white cohesive failure marks were generated. The remaining. Moreover, the tension at the time of unwinding was not stable.

  Furthermore, when slitting with a laser blade in the next process, due to the influence of distortion at the end due to unwinding failure and uneven thickness of the adhesive layer at the end, the slit blade does not enter constantly, A problem occurred in which the end portion was raised. The end portion of the film obtained by the slit was in a state where white powder was sprayed, and because of the increased thickness, there was a problem such as a high winding shape.

  Further, the base film was peeled off from the polarizing laminated film obtained by slitting, but the end portion was raised and could not be smoothly peeled off, and the end portion became jagged. Moreover, the malfunction that powder adheres to the film back surface also arose. Furthermore, when the end portion was observed, the adhesive was partially insufficient, and there was a defective portion having a gap between the protective film and the polarizer layer.

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

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

  DESCRIPTION OF SYMBOLS 11 Base film, 11a Uncoated part, 12 Resin layer (polarizer layer), 13 Adhesive layer, 14 Protective film.

Claims (8)

A base film, a polarizer layer, an adhesive layer, a protective film is a long polarizing laminate film laminated in this order,
The thickness of the base film is 5 to 150 μm,
In the width direction of the polarizing laminated film, both ends of the polarizer layer are positioned inside both ends of the base film and the protective film, and both ends of the adhesive layer are positioned outside both ends of the polarizer layer. And the polarizing laminated film located inside the both ends of the said base film and the said protective film. A base film, a polarizer layer, an adhesive layer, a protective film is a long polarizing laminate film laminated in this order,
In the width direction of the polarizing laminated film, both ends of the polarizer layer are positioned inside both ends of the base film and the protective film, and both ends of the adhesive layer are positioned outside both ends of the polarizer layer. And the polarizing laminated film which is located inside the both ends of the said base film and the said protective film, and the both ends of the said protective film are located outside the both ends of the said base film. The polarizer layer is a polyvinyl alcohol-based resin layer dichroic dye is adsorbed and oriented, a thickness is 10μm or less, polarizing laminate film according to claim 1 or 2. The polarizing laminated film roll by which the polarizing laminated film of any one of Claims 1-3 was wound. A method for producing a polarizing laminated film comprising a base film having a thickness of 5 to 150 μm, wherein a polyvinyl alcohol-based resin layer is formed on at least one surface of a long base film to form the laminated film. A laminating process to obtain;
A stretching step of uniaxially stretching the laminated film;
A dyeing step of dyeing the resin layer of the laminated film subjected to the uniaxial stretching with a dichroic dye;
A crosslinking step in which the resin layer of the laminated film subjected to the dyeing is immersed in a solution containing a crosslinking agent to be crosslinked to form a polarizer layer;
A bonding step of bonding a protective film to the surface of the polarizer layer in the cross-linked film opposite to the surface on the substrate film side of the polarizer layer via an adhesive layer in this order. ,
In the laminating step, a portion not forming the polyvinyl alcohol-based resin layer is provided at both ends in the width direction of the base film,
In the bonding step, 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 both ends of the adhesive layer are both ends of the polarizer layer. The manufacturing method of a polarizing laminated film which bonds so that it may be located more outside and may be located inside the both ends of the said base film and the said protective film. A laminating step of obtaining a laminated film by forming a polyvinyl alcohol-based resin layer on at least one surface of the long base film;
A stretching step of uniaxially stretching the laminated film;
A dyeing step of dyeing the resin layer of the laminated film subjected to the uniaxial stretching with a dichroic dye;
A crosslinking step in which the resin layer of the laminated film subjected to the dyeing is immersed in a solution containing a crosslinking agent to be crosslinked to form a polarizer layer;
A bonding step of bonding a protective film to the surface of the polarizer layer in the cross-linked film opposite to the surface on the substrate film side of the polarizer layer via an adhesive layer in this order. ,
In the laminating step, a portion not forming the polyvinyl alcohol-based resin layer is provided at both ends in the width direction of the base film,
In the bonding step, 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 both ends of the adhesive layer are both ends of the polarizer layer. A polarizing laminated film, which is positioned on the outer side and is positioned on the inner side of both ends of the base film and the protective film, and is bonded so that both ends of the protective film are positioned on the outer side of both ends of the base film. Manufacturing method. After said bonding step comprises the step of removing by cutting a portion from the laminated film and the base film and the protective film is adhered directly via the adhesive layer, according to claim 5 or 6 The manufacturing method of the polarizing laminated film of description. The manufacturing method of a polarizing plate which has the peeling process which peels and removes the said base film from the polarizing laminated film manufactured by the method of Claim 7 .

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