WO2014175462A1 - Method for manufacturing polarizing plate - Google Patents

Method for manufacturing polarizing plate Download PDF

Info

Publication number
WO2014175462A1
WO2014175462A1 PCT/JP2014/061926 JP2014061926W WO2014175462A1 WO 2014175462 A1 WO2014175462 A1 WO 2014175462A1 JP 2014061926 W JP2014061926 W JP 2014061926W WO 2014175462 A1 WO2014175462 A1 WO 2014175462A1
Authority
WO
WIPO (PCT)
Prior art keywords
protective film
polarizing plate
polarizer
resin
adhesive
Prior art date
Application number
PCT/JP2014/061926
Other languages
French (fr)
Japanese (ja)
Inventor
森定　郁生
Original Assignee
住友化学株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 住友化学株式会社 filed Critical 住友化学株式会社
Priority to CN201480022243.3A priority Critical patent/CN105122102A/en
Priority to JP2015513869A priority patent/JPWO2014175462A1/en
Priority to KR1020157030254A priority patent/KR20160000459A/en
Publication of WO2014175462A1 publication Critical patent/WO2014175462A1/en

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/14—Protective coatings, e.g. hard coatings
    • G02B1/105—
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133528—Polarisers

Definitions

  • the present invention relates to a method for producing a polarizing plate that is less prone to cracking.
  • the polarizing plate is widely used as a polarization supply element, a polarization detection element, and the like in a liquid crystal display device.
  • a polarizer protective film made of triacetyl cellulose (TAC) is fixed to a polarizer obtained by adsorbing and orienting a dichroic dye on a polyvinyl alcohol (PVA) film.
  • TAC triacetyl cellulose
  • PVA polyvinyl alcohol
  • the manufacturing process of a polarizing plate generally comprises a lamination process and a cutting process for each layer.
  • a lamination process is a process of laminating
  • a polarizer protective film Usually, of both surfaces, one is laminated with a polarizing plate protective film, and the other is laminated with an adhesive protective film.
  • a cutting process is a process of cut
  • the cutting of the laminated plate in the cutting step is usually performed by applying a blade to the polarizing plate protective film from the surface of the polarizing plate protective film.
  • the polarizing plate protective film side is usually the front surface
  • the adhesive protective film side is the back surface, even in the production line, This is because the layers are usually laminated so that the polarizing plate protective film becomes the upper surface (front surface).
  • the polarizing plate thus obtained is shipped with a polarizing plate protective film laminated on one side and an adhesive protective film laminated on the other side, and is attached to a liquid crystal cell at a liquid crystal panel manufacturing factory. Combined.
  • the polarizing plate When laminating the polarizing plate and the liquid crystal cell, the polarizing plate is affixed to the liquid crystal cell with an adhesive that appears by peeling off the adhesive protective film laminated on the polarizing plate.
  • a bonded product of a polarizing plate and a liquid crystal cell is usually inspected for defects while the polarizing plate protective film is still laminated. Therefore, if there is a defect in the polarizing plate protective film, the entire bonded product will be disposed of. Therefore, when manufacturing the polarizing plate, it is necessary to be careful not to damage the polarizing plate protective film. .
  • the pressure-sensitive adhesive protective film peeled off when the polarizing plate is attached to the liquid crystal cell a slight scratch is allowed.
  • an object of the present invention is to provide a method for obtaining a polarizing plate that hardly causes cracks even when moisture adheres thereto.
  • the polarizing plate is formed of a polarizer and a protective film fixed to at least one surface of the polarizer.
  • the polarizing plate is formed of a polarizer, a protective film fixed to at least one surface of the polarizer, and at least one retardation plate, [1] or [2] the method of.
  • the manufacturing method of a polarizing plate cut to a predetermined size according to the present invention includes a polarizing plate protective film laminated on one surface and the other surface
  • the polarizing laminate having the adhesive protective film laminated thereon is cut by applying a blade to the surface on the adhesive protective film side.
  • the polarizing plate protective film is a film for protecting the surface of the polarizing plate from damage, abrasion and the like.
  • the polarizing plate protective film is bonded to the polarizing plate due to weak adhesiveness, and as described above, it remains on the surface of the polarizing plate after bonding the liquid crystal cell and the polarizing plate. It is peeled off when used as a liquid crystal display device.
  • the polarizing plate protective film is easy to handle and preferably has a certain degree of transparency.
  • Such a polarizing plate protective film is preferably formed from a resin such as a polyethylene resin, a polypropylene resin, or a polyethylene terephthalate resin, and an adhesive.
  • the polarizing plate protective film may be a single layer or may have a multilayer structure in which two or more resin layers are laminated.
  • the polarizing plate protective film usually has a thickness of about 40 to 150 ⁇ m, preferably about 45 to 70 ⁇ m.
  • sanitect manufactured by Sanei Kaken Co., Ltd.
  • E-mask in which an adhesive is applied to the surface of the polyethylene terephthalate resin film
  • MASTACK manufactured by Fujimori Kogyo Co., Ltd.
  • Tretec manufactured by Toray Film Processing Co., Ltd.
  • the pressure-sensitive adhesive protective film is a film for protecting the pressure-sensitive adhesive layer provided on the surface of the polarizing plate. In the case where the pressure-sensitive adhesive layer is unprotected and exposed, dust may adhere to the polarizing plate or the polarizing plate may adhere to an unintended portion before actually using the polarizing plate. In order to prevent this, a pressure-sensitive adhesive protective film is used.
  • the adhesive protective film is not particularly limited as long as it is a release-treated plastic film. For example, silicone is applied to a film obtained by processing a thermoplastic resin (polyethylene terephthalate, polyethylene naphthoate, polyethylene, polypropylene, etc.).
  • Examples thereof include a film subjected to a release treatment with a resin or the like.
  • an adhesive protective film a commercially available adhesive protective film that can be used as a release film has a thickness of usually about 15 to 80 ⁇ m, preferably about 20 to 50 ⁇ m.
  • the polarizing plate of this invention has an adhesive layer in the surface where the adhesive protective film is laminated
  • This pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive conventionally used for bonding a liquid crystal cell and a polarizing plate.
  • examples of such an adhesive include acrylic, rubber, urethane, silicone, and polyvinyl ether adhesives.
  • an acrylic pressure-sensitive adhesive based on an acrylic resin excellent in transparency, weather resistance, heat resistance and the like as a base polymer is preferable.
  • the acrylic pressure-sensitive adhesive is not particularly limited, and examples thereof include (meth) acrylic acid esters such as butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.
  • examples thereof include pressure-sensitive adhesives in which a base polymer is used as a base polymer or a copolymer polymer containing two or more of these (meth) acrylic acid esters.
  • (Meth) acryl means “acryl” or “methacryl”.
  • a polar monomer is preferably included.
  • Examples of the polar monomer include monomers having a functional group such as a carboxyl group, a hydroxyl group, an amide group, an amino group, and an epoxy group.
  • a functional group such as a carboxyl group, a hydroxyl group, an amide group, an amino group, and an epoxy group.
  • (meth) acrylic acid, (meth) acrylic acid 2-hydroxypropyl examples include hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, and glycidyl (meth) acrylate.
  • the acrylic pressure-sensitive adhesive may be used alone or in combination with a crosslinking agent.
  • cross-linking agents divalent or higher polyvalent metal salts that form carboxylic acid metal salts with carboxyl groups, polyamine compounds that form amide bonds with carboxyl groups, polyepoxy compounds that form ester bonds with carboxyl groups Or a polyol compound, the polyisocyanate compound etc. which react with a carboxyl group and form an amide bond are mentioned.
  • a polyisocyanate compound is preferably used.
  • An active energy ray-curable pressure-sensitive adhesive is a pressure-sensitive adhesive that has a property of being cured by irradiation with active energy rays such as ultraviolet rays and electron beams, and has an adhesive property even before irradiation with active energy rays. It adheres to the adherend such as, and is cured by irradiation with active energy rays, so that the adhesion can be adjusted.
  • active energy ray curable adhesive an ultraviolet curable adhesive is preferable.
  • the active energy ray-curable pressure-sensitive adhesive usually contains an acrylic pressure-sensitive adhesive and an active energy ray-polymerizable compound as main components. Furthermore, a crosslinking agent may be added, and a photopolymerization initiator or a photosensitizer may be added as necessary.
  • the adhesive may be a natural resin, a synthetic resin, a tackifier resin, an antioxidant, an ultraviolet absorber, a dye, a pigment, an antifoaming agent, a corrosion inhibitor, a polymerization initiator, if necessary.
  • the pressure-sensitive adhesive layer preferably has a thickness of 1 to 40 ⁇ m. It is preferable to apply a thin layer within a range that does not impair the workability and durability of the laminate, and more preferably a thickness of 3 to 25 ⁇ m from the viewpoint of maintaining better workability and suppressing the dimensional change of the polarizing plate. If the thickness of the pressure-sensitive adhesive layer is too thin, the tackiness is lowered, and if it is too thick, problems such as the pressure-sensitive adhesive sticking out of the laminate are likely to occur.
  • the polarizing plate has a function of converting natural light into linearly polarized light.
  • a polarizing plate is a laminate of a polarizer and a polarizer protective film fixed to at least one surface of the polarizer, and other functional films and functional sheets are laminated as necessary. May be.
  • the polarizer include the following (a) and (b).
  • PVA polyvinyl alcohol
  • EVA ethylene / vinyl acetate
  • (B) A polyvinyl alcohol / polyvinylene copolymer having an oriented molecular chain of a dichroic dehydrated product of polyvinyl alcohol (polyvinylene) in a molecularly oriented polyvinyl alcohol film.
  • the polyvinyl alcohol-based resin is usually obtained by saponifying a polyvinyl acetate-based resin.
  • the saponification degree is usually 85 mol% or more, preferably 90 mol or more, more preferably 99 to 100 mol%.
  • the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers with other monomers copolymerizable with vinyl acetate, such as ethylene-vinyl acetate copolymer. Can be mentioned.
  • Examples of other monomers include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids.
  • the molecular weight of the polyvinyl alcohol-based resin is not particularly limited, and is preferably about 1000 to 10000, more preferably about 1500 to 5000.
  • the polyvinyl alcohol may be modified.
  • modified polyvinyl alcohol include polyvinyl formal modified with aldehydes, polyvinyl acetal, polyvinyl butyral, and the like.
  • an unstretched film of the above-mentioned polyvinyl alcohol resin having a thickness of preferably 20 to 100 ⁇ m, more preferably 30 to 80 ⁇ m is used.
  • the width of the film is preferably about 1500 to 4000 mm.
  • This unstretched film is processed in the order of, for example, a swelling process, a dyeing process, a crosslinking process, and a water washing process, subjected to uniaxial stretching in the process up to the crosslinking process, and finally dried to obtain a polarizer.
  • the polarizer usually has a thickness of 5 to 50 ⁇ m, preferably 5 to 30 ⁇ m.
  • dichroic dye used in the dyeing process examples include iodine and organic dyes.
  • 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. are mentioned. These dichroic dyes may be used alone or in combination of two or more.
  • crosslinking agent used in the crosslinking step Conventionally known substances can be used as the crosslinking agent used in the crosslinking step. Examples thereof include boron compounds such as boric acid and borax, glyoxal, and glutaraldehyde. These crosslinking agents may be used alone or in combination of two or more.
  • the polarizer protective film is a film for protecting such a polarizer, and is fixed to at least one surface of the polarizer.
  • Examples of the polarizer protective film include films conventionally used in this field. For example, cycloolefin resin films, cellulose acetate resin films, polyester resin films (for example, polyethylene terephthalate, polyethylene naphthalate, poly Butylene terephthalate), polycarbonate resin film, acrylic resin film, polypropylene resin film, and the like.
  • the polarizer protective film is preferably transparent and has excellent chemical resistance, and more preferably a cellulose acetate-based resin film.
  • the cellulose acetate-based resin is a part of cellulose or a complete acetate ester, and examples thereof include triacetyl cellulose (TAC), diacetyl cellulose, and cellulose acetate propionate.
  • TAC triacetyl cellulose
  • diacetyl cellulose diacetyl cellulose
  • cellulose acetate propionate examples thereof include triacetyl cellulose (TAC), diacetyl cellulose, and cellulose acetate propionate.
  • Cellulose acetate-based resin films are commercially available.
  • Fujitac registered trademark
  • TD80 Fujitac (registered trademark)
  • TD80UF Fujiji Film Co., Ltd.
  • Fujitac registered trademark
  • TD80UZ Fuji Film Co., Ltd.
  • KC8UX2M Konica Minolta Opto Co., Ltd.
  • KC4UY Konica Minolta Opto Co., Ltd.
  • the polarizer protective film only needs to be fixed to at least one surface of the polarizer.
  • the same polarizer protective film may be sufficient as both surfaces, and a different polarizer protective film may be sufficient.
  • triacetyl cellulose may be fixed on both sides of the polarizer, or triacetyl cellulose may be fixed on one side and another polarizer protective film may be fixed on the remaining side.
  • a cycloolefin type-resin film is used.
  • Cycloolefin resins are commercially available. For example, Topas (registered trademark) (manufactured by Ticona), Arton (registered trademark) (manufactured by JSR Corporation), ZEONOR (registered trademark) (Nippon ZEON Corporation). ZEONEX (registered trademark) (manufactured by Nippon Zeon Co., Ltd.), Alpe (registered trademark) (manufactured by Mitsui Chemicals, Inc.), and the like.
  • a known method such as a solvent casting method or a melt extrusion method is appropriately used.
  • ESCINA registered trademark
  • SCA40 manufactured by Sekisui Chemical Co., Ltd.
  • Zeonor registered trademark
  • a commercially available olefin resin film may be used.
  • the polarizer protective film usually has a thickness of about 10 to 150 ⁇ m, preferably about 20 to 100 ⁇ m.
  • Phase difference plate When producing a polarizing plate, a retardation plate is often used as a functional film or a functional sheet to be laminated as necessary together with a polarizer and a polarizer protective film.
  • the phase difference plate is employed according to the characteristics required for a liquid crystal panel or a liquid crystal display device.
  • a quarter wave plate is provided as the retardation plate.
  • a polarizing plate is used as a linear polarizing plate, as a phase difference plate, the biaxial phase difference film which has an optical compensation function, the non-orientation film which has a surface protection function, etc. are employ
  • a quarter-wave plate is a plate (film) that exhibits a phase difference of almost 1 ⁇ 4 wavelength (90 degrees) with respect to any light in the wavelength region of visible light (380 to 780 nm). And a function of mutually converting circularly polarized light and a function of compensating the viewing angle of the liquid crystal cell.
  • the material constituting the retardation plate is not particularly limited.
  • a (meth) acrylic resin such as a methyl methacrylate resin
  • an olefin resin such as a methyl methacrylate resin
  • a polyvinyl chloride resin such as a polyvinyl chloride resin
  • a cellulose resin such as a cellulose resin
  • a styrene resin such as acrylonitrile.
  • ABS resin acrylonitrile-styrene copolymer resin
  • AS resin acrylonitrile-styrene copolymer resin
  • polyvinyl acetate resin polyvinylidene chloride resin
  • polyamide resin polyacetal resin
  • polycarbonate resin Modified polyphenylene ether resin
  • polyester resin polyethylene terephthalate, polybutylene terephthalate, etc.
  • polysulfone resin polyethersulfone resin
  • polyarylate resin polyamideimide resin
  • polyimide resin polyimide resin
  • epoxy resin oxygen
  • oxygen oxygen
  • the phase difference plate When using a phase difference plate, the phase difference plate may be a single layer or two or more layers. When two or more retardation plates are stacked, the same retardation plate or different retardation plates may be used, but different retardation plates are usually used. In addition, when using the same phase difference plate, it is normally used by changing each axial angle, but you may use it with the same axial angle.
  • the retardation plate usually has a thickness of about 10 to 100 ⁇ m, preferably about 20 to 80 ⁇ m.
  • a polarizing laminate having a polarizing plate protective film laminated on one surface and an adhesive protective film laminated on the other surface is the polarizing plate protective film, adhesive protective film, polarizer, polarizer protective film described above, And it is the laminated body obtained by laminating
  • a polarizing laminate, a polarizer, a polarizer protective film, and another functional film or functional sheet are generally fixed with an adhesive or a pressure-sensitive adhesive.
  • the adhesive and the pressure-sensitive adhesive are not limited as long as they do not inhibit the function as a polarizing plate.
  • polyvinyl alcohol resin, epoxy resin, urethane resin, cyanoacrylate resin, acrylamide resin and the like are used as components. Adhesives and pressure-sensitive adhesives.
  • One preferred adhesive is a solventless adhesive.
  • Solventless adhesives do not contain a significant amount of solvent and are curable compounds (monomers, oligomers, etc.) that are reactively cured by irradiation with active energy rays (for example, ultraviolet rays, visible rays, electron beams, X-rays, etc.). And an adhesive that exhibits a fixing function by curing of the curable compound.
  • active energy rays for example, ultraviolet rays, visible rays, electron beams, X-rays, etc.
  • Such an adhesive usually contains a polymerization initiator together with a curable compound.
  • the laminate as the raw fabric is configured according to the desired use of the polarizing plate.
  • polarizing plate protective film / polarizing plate (polarizer protective film / polarizer) / adhesive layer / adhesive protective film” “Polarizing plate protective film / Polarizing plate (Polarizer protective film / Polarizer / Phase difference plate) / Adhesive layer / Adhesive protective film”, “Polarizing plate protective film / Polarizer (Polarizer protective film / Polarizer / "First retardation plate / second retardation plate) / adhesive layer / adhesive protective film”, “polarizing plate protective film / polarizing plate (polarizer protective film / polarizer / polarizer protective film) / adhesive Layer / adhesive protective film ”,“ polarizing plate protective film / polarizing plate (polarizer protective film / polarizer / polarizer protective film / retardation plate) / adhesive layer / adhesive protective film ”,“ polarizing plate protective film ” / Polarizing plate (polarizer protective film /
  • the thickness of the laminate (raw material) thus obtained is appropriately set according to the use of the polarizing plate as a product, and is usually about 100 to 600 ⁇ m, preferably about 150 to 400 ⁇ m.
  • a laminate (raw fabric) is usually produced by using a long sheet wound on a roll as a raw material, and subjecting it to various treatments continuously or intermittently. And in this invention, it is a stage of manufacture of a laminated body (original fabric) normally, Comprising: Before implementing a cutting process, it cut
  • the obtained short laminate (raw material) is larger than the target polarizing plate, and has a size that can obtain a plurality of polarizing plates, for example, 4 to 80 sheets.
  • a cutting process is a process of cutting the said laminated body (raw material), and obtaining the polarizing plate of the predetermined dimension by which the protective film was laminated
  • the laminate (raw material) is cut by applying a blade to the surface of the pressure-sensitive adhesive protective film.
  • the surface of the pressure-sensitive adhesive protective film When it does, it is the surface of the pressure-sensitive adhesive protective film, and is cut by placing another object (for example, a covering sheet described later) on the laminate (original fabric) placed so that the pressure-sensitive adhesive protective film is on the upper side. In the case, it is the upper surface of the object.
  • another object for example, a covering sheet described later
  • the entire bonded product (liquid crystal panel) obtained in the defect inspection at the liquid crystal panel manufacturing factory will be disposed of. Extreme care must be taken to prevent scratches on the protective film.
  • the pressure-sensitive adhesive protective film peeled off when the polarizing plate is attached to the liquid crystal cell a slight scratch is allowed. Therefore, at the time of manufacturing the polarizing plate in the present invention, as usual, it is usually handled so that the polarizing plate protective film is on the upper surface side. Is preferred. In this cutting step, extreme care should be taken so that the polarizing plate protective film on the lower surface is not damaged.
  • the covering sheet is not limited as long as it is a sheet made of a material that can be cut together with the laminate (raw material). For example, a resin film (polyethylene film, polypropylene film, etc.), cloth (woven cloth, non-woven cloth, etc.) And paper.
  • a resin film polyethylene film, polypropylene film, etc.
  • cloth woven cloth, non-woven cloth, etc.
  • cover sheet it is preferable to place the cover sheet on the upper surface of the pressure-sensitive adhesive protective film and remove bubbles between the pressure-sensitive adhesive protective film and the cover sheet.
  • the cutting of the laminate (raw material) is performed with a conventionally used cutting machine, and is not particularly limited.
  • a laminate (raw material) having a size (usually about 500 mm x 500 mm to 1000 mm x 1000 mm) according to the cutting machine is prepared, and the laminate is placed with the adhesive protective film face up.
  • the (raw material) may be fixed to a cutting machine, covered with a coating film as necessary, and cut to a desired dimension.
  • the laminate (raw material) is cut by applying a blade to the surface on the pressure-sensitive adhesive protective film side, so that the blade used for cutting is a blade that is cut by vertical movement (so-called guillotine blade) ) Is preferably employed.
  • Example 1 A polarizer protective film (thickness 44 ⁇ m) made of triacetyl cellulose having a hard coat layer on one surface of a polarizer (thickness 29 ⁇ m) in which iodine is adsorbed and oriented on a long polyvinyl alcohol is bonded to a polyvinyl alcohol resin. Glued with agent.
  • a polarizing plate protective film was bonded to the surface of the polarizer protective film.
  • the polarizing plate protective film used is a polyethylene terephthalate resin film (thickness 49 ⁇ m) coated with an acrylic adhesive. And the acrylic adhesive was apply
  • An acrylic pressure-sensitive adhesive is applied to one surface of a retardation film (Sumitomo Chemical Co., Ltd., SUMIKALITE SES430270, thickness 33 ⁇ m) made of a stretched film of norbornene resin and having an in-plane retardation of 270 nm. did.
  • This retardation plate having an in-plane retardation of 270 nm is referred to as a “first retardation plate”.
  • coated was bonded to the surface where the adhesive of the 1st phase difference plate was not apply
  • an acrylic pressure-sensitive adhesive was applied to one surface of a retardation plate (Sumitomo Chemical Co., Ltd., Sumikalite SES430140, thickness 28 ⁇ m) having an in-plane retardation of 140 nm, and a pressure-sensitive adhesive layer. Formed.
  • the retardation plate having an in-plane retardation of 140 nm is referred to as a “second retardation plate”.
  • a pressure-sensitive adhesive protective film thickness 38 ⁇ m formed of polyethylene terephthalate resin was bonded.
  • the obtained laminate (raw fabric) was placed on a cutting plate of a cutting machine so that the pressure-sensitive adhesive protective film was on the upper surface, and the ends were fixed with tape. Cover the laminate (raw fabric) fixed with tape with a polyethylene film and press it with your hand to remove air bubbles between the adhesive protective film and the polyethylene film.
  • the laminated body (raw material) was cut on a polyethylene film to obtain a 90 mm ⁇ 51 mm polarizing plate.
  • the obtained polarizing plate was dried at 80 ° C. for 1 hour, dried, and then allowed to stand at 23 ° C. and 55% humidity for 15 minutes. Next, the polarizing plate was immersed in water (23 ° C.) for 30 minutes, and the presence or absence of cracks was observed using a magnifying glass and a microscope, but no cracks were generated.
  • Example 2 A polarizing plate was obtained in the same manner as in Example 1 except that the laminate (raw material) obtained in Example 1 was cut without being covered with a polyethylene film. About the obtained polarizing plate, although the presence or absence of the crack was observed in the procedure similar to Example 1, the crack did not generate
  • Example 1 Comparative Example 1 Except that the laminate (raw material) obtained in Example 1 was placed on a backing plate of a cutting machine so that the polarizing plate protective film was on the upper surface, and was cut without being covered with a polyethylene film. A polarizing plate was obtained in the same manner as in Example 1. About the obtained polarizing plate, when the presence or absence of the crack was observed using the loupe and the microscope in the same procedure as Example 1, many fine cracks generate
  • the polarizing plate obtained by the production method of the present invention is hardly cracked even when moisture adheres, and is used for, for example, a portable information terminal such as a mobile phone or a smartphone.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Polarising Elements (AREA)
  • Nonlinear Science (AREA)
  • Liquid Crystal (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)

Abstract

This manufacturing method for a polarizing plate manufactures a polarizing plate in which protective films are laminated on both surfaces by bringing the blade into contact with a surface on an adhesive compound protective film side of a polarizing laminated plate in which a polarizing plate protective film is laminated on one surface and an adhesive compound protective film is laminated on the other surface and cutting the same so as to form a prescribed size. In addition, in this manufacturing method for a polarizing plate, the upper surface of the adhesive compound protective film is preferably covered by a covering sheet when cutting the polarizing laminated plate.

Description

偏光板の製造方法Manufacturing method of polarizing plate
　本発明は、クラックが生じにくい偏光板の製造方法に関する。 The present invention relates to a method for producing a polarizing plate that is less prone to cracking.
　偏光板は、液晶表示装置における偏光の供給素子、偏光の検出素子などとして広く用いられている。このような偏光板としては、従来、ポリビニルアルコール（ＰＶＡ）系フィルムに二色性色素を吸着および配向させて得られる偏光子に、トリアセチルセルロース（ＴＡＣ）からなる偏光子保護フィルムを固着したものが用いられている（特開２０１０−２１１２１３号公報（特許文献１）および特開２０１０−２７６６７３号公報（特許文献２））。 The polarizing plate is widely used as a polarization supply element, a polarization detection element, and the like in a liquid crystal display device. As such a polarizing plate, conventionally, a polarizer protective film made of triacetyl cellulose (TAC) is fixed to a polarizer obtained by adsorbing and orienting a dichroic dye on a polyvinyl alcohol (PVA) film. Are used (Japanese Patent Laid-Open No. 2010-212213 (Patent Document 1) and Japanese Patent Laid-Open No. 2010-276673 (Patent Document 2)).
　偏光板の製造工程は、一般に、各層の積層工程および切断工程からなる。
　積層工程は、偏光子、偏光子保護フィルム、粘着剤、偏光板保護フィルム、粘着剤保護フィルムなどや、必要に応じて位相差板などを積層する工程である。通常、両表面のうち、一方は偏光板保護フィルムが積層され、他方は粘着剤保護フィルムが積層されている。切断工程は、積層工程で得られた積層板を、所望の寸法に切断して、両表面に保護フィルムが積層された偏光板を得る工程である。 The manufacturing process of a polarizing plate generally comprises a lamination process and a cutting process for each layer.
A lamination process is a process of laminating | stacking a phase difference plate etc. as needed, such as a polarizer, a polarizer protective film, an adhesive, a polarizing plate protective film, an adhesive protective film. Usually, of both surfaces, one is laminated with a polarizing plate protective film, and the other is laminated with an adhesive protective film. A cutting process is a process of cut | disconnecting the laminated board obtained at the lamination process to a desired dimension, and obtaining the polarizing plate by which the protective film was laminated | stacked on both surfaces.
　切断工程における積層板の切断は、通常、偏光板保護フィルムの面から、偏光板保護フィルムに刃を当てて、行われる。これは、両面に保護フィルムが積層された偏光板を製品形態にした場合、偏光板保護フィルム側がおもて面となり、粘着剤保護フィルム側が裏面となるのが通常であり、製造ラインにおいても、通常、偏光板保護フィルムが上面（おもて面）となるように各層を積層しているためである。通常、こうして得られた偏光板は、一方の面に偏光板保護フィルムが積層され、他方の面に粘着剤保護フィルムが積層された状態で出荷され、液晶パネル製造工場にて、液晶セルと貼合される。偏光板と液晶セルとを貼合する際には、偏光板に積層された粘着剤保護フィルムを剥がして現れる粘着剤で、偏光板を液晶セルに貼り付ける。液晶パネル製造工場では通常、偏光板と液晶セルとの貼合品は、偏光板保護フィルムが積層されたままの状態で、欠陥検査をする。そのため、偏光板保護フィルムに欠陥があると、貼合品全体が廃棄処分となったりするので、偏光板の製造時には、偏光板保護フィルムに傷などが付かないよう、細心の注意が必要である。一方で、液晶セルに偏光板を貼り付ける際に剥がされる粘着剤保護フィルムについては、少々の傷は許容される。 The cutting of the laminated plate in the cutting step is usually performed by applying a blade to the polarizing plate protective film from the surface of the polarizing plate protective film. This is the case where the polarizing plate with the protective film laminated on both sides is in the product form, the polarizing plate protective film side is usually the front surface, and the adhesive protective film side is the back surface, even in the production line, This is because the layers are usually laminated so that the polarizing plate protective film becomes the upper surface (front surface). Usually, the polarizing plate thus obtained is shipped with a polarizing plate protective film laminated on one side and an adhesive protective film laminated on the other side, and is attached to a liquid crystal cell at a liquid crystal panel manufacturing factory. Combined. When laminating the polarizing plate and the liquid crystal cell, the polarizing plate is affixed to the liquid crystal cell with an adhesive that appears by peeling off the adhesive protective film laminated on the polarizing plate. In a liquid crystal panel manufacturing factory, a bonded product of a polarizing plate and a liquid crystal cell is usually inspected for defects while the polarizing plate protective film is still laminated. Therefore, if there is a defect in the polarizing plate protective film, the entire bonded product will be disposed of. Therefore, when manufacturing the polarizing plate, it is necessary to be careful not to damage the polarizing plate protective film. . On the other hand, for the pressure-sensitive adhesive protective film peeled off when the polarizing plate is attached to the liquid crystal cell, a slight scratch is allowed.
　近年、携帯電話機、スマートフォンなどの携帯情報端末や、タッチパネルを有する液晶表示装置などの高性能化に伴い、これらに用いられる偏光板について、より過酷な条件下で使用しても不具合が生じないなどの性能が要求されている。 In recent years, with the improvement in performance of portable information terminals such as mobile phones and smartphones, and liquid crystal display devices having a touch panel, the use of polarizing plates used in these devices does not cause problems even when used under more severe conditions. Performance is required.
　本発明者の検討により、偏光板は、結露などにより水分が付着すると、亀裂（クラック）が生じやすくなることがわかった。このような事象は、例えば、携帯電話機、スマートフォンなどの携帯情報端末を持って、夏に屋外から冷房の効いた屋内に入った場合や、冬に暖房の効いた屋内から外出した場合など、寒暖の差が大きい場所を行き来すると生じるおそれがある。
　そこで、本発明者は、結露などにより水分が付着してもクラックが生じないような偏光板を製造する検討を行い、本発明を完成した。
　即ち、本発明の課題は、水分が付着してもクラックが生じにくい偏光板を得るための方法を提供することにある。 According to the study of the present inventor, it has been found that the polarizing plate is likely to be cracked when moisture adheres due to condensation. Such an event may occur when, for example, a portable information terminal such as a mobile phone or a smart phone is used to enter an air-conditioned room in the summer or go out of an air-conditioned room in the winter. There is a risk that it will occur if you go back and forth between places with a large difference.
Therefore, the present inventor has studied to produce a polarizing plate that does not cause cracks even if moisture adheres due to condensation or the like, and has completed the present invention.
That is, an object of the present invention is to provide a method for obtaining a polarizing plate that hardly causes cracks even when moisture adheres thereto.
　本発明は、上記課題を解決するため、以下の手段を提供する。
　〔１〕一方の表面に偏光板保護フィルムが積層され、他方の表面に粘着剤保護フィルムが積層された偏光性積層板を、その前記粘着剤保護フィルム側の表面に刃を当てて、所定の大きさとなるように切断することにより、両表面に保護フィルムが積層された偏光板を製造する方法。
　〔２〕前記偏光性積層板を切断する際、前記粘着剤保護フィルムの上面が被覆シートで覆われている、〔１〕に記載の方法。
　〔３〕前記偏光板が、偏光子と、該偏光子の少なくとも一方の表面に固着された保護膜とで形成されている、〔１〕または〔２〕に記載の方法。
　〔４〕前記偏光板が、偏光子と、該偏光子の少なくとも一方の表面に固着された保護膜と、少なくとも１つの位相差板とで形成されている、〔１〕または〔２〕に記載の方法。 The present invention provides the following means in order to solve the above problems.
[1] A polarizing laminate in which a polarizing plate protective film is laminated on one surface and an adhesive protective film is laminated on the other surface, and a blade is applied to the surface on the adhesive protective film side, A method for producing a polarizing plate in which protective films are laminated on both surfaces by cutting to a size.
[2] The method according to [1], wherein an upper surface of the pressure-sensitive adhesive protective film is covered with a covering sheet when the polarizing laminate is cut.
[3] The method according to [1] or [2], wherein the polarizing plate is formed of a polarizer and a protective film fixed to at least one surface of the polarizer.
[4] The polarizing plate is formed of a polarizer, a protective film fixed to at least one surface of the polarizer, and at least one retardation plate, [1] or [2] the method of.
　本発明に係る偏光板の製造方法によれば、水分が付着してもクラックが生じにくい偏光板を得ることができる。 According to the method for producing a polarizing plate according to the present invention, it is possible to obtain a polarizing plate in which cracks are unlikely to occur even when moisture adheres.
　本発明に係る所定寸法に切断された偏光板の製造方法（以下、単に「本発明の製造方法」と記載する場合がある）は、一方の表面に偏光板保護フィルムが積層され、他方の表面に粘着剤保護フィルムが積層された偏光性積層板を、粘着剤保護フィルム側の表面に刃を当てて切断する。 The manufacturing method of a polarizing plate cut to a predetermined size according to the present invention (hereinafter sometimes simply referred to as “the manufacturing method of the present invention”) includes a polarizing plate protective film laminated on one surface and the other surface The polarizing laminate having the adhesive protective film laminated thereon is cut by applying a blade to the surface on the adhesive protective film side.
　（偏光板保護フィルム）
　偏光板保護フィルムは、偏光板の表面を損傷、摩耗などから保護するためのフィルムである。偏光板保護フィルムは、弱い粘着性によって偏光板に貼合されており、前述の通り、液晶セルと偏光板とを貼合した後も、偏光板の表面に残っているが、一般消費者が液晶表示装置として使用する時には剥離される。偏光板保護フィルムは、ハンドリングが容易であり、ある程度の透明性を有するものが好ましい。このような偏光板保護フィルムは、好ましくは、ポリエチレン系樹脂、ポリプロピレン系樹脂、ポリエチレンテレフタレート系樹脂などの樹脂と、粘着剤とから形成される。偏光板保護フィルムは、単層でもよく、２種以上の樹脂層を積層させた多層構造を有していてもよい。偏光板保護フィルムは、通常は４０~１５０μｍ程度、好ましくは４５~７０μｍ程度の厚みを有する。 (Polarizing plate protective film)
The polarizing plate protective film is a film for protecting the surface of the polarizing plate from damage, abrasion and the like. The polarizing plate protective film is bonded to the polarizing plate due to weak adhesiveness, and as described above, it remains on the surface of the polarizing plate after bonding the liquid crystal cell and the polarizing plate. It is peeled off when used as a liquid crystal display device. The polarizing plate protective film is easy to handle and preferably has a certain degree of transparency. Such a polarizing plate protective film is preferably formed from a resin such as a polyethylene resin, a polypropylene resin, or a polyethylene terephthalate resin, and an adhesive. The polarizing plate protective film may be a single layer or may have a multilayer structure in which two or more resin layers are laminated. The polarizing plate protective film usually has a thickness of about 40 to 150 μm, preferably about 45 to 70 μm.
　偏光板保護フィルムとしては、表面に粘着剤が塗布されている樹脂フィルムや、自己粘着性を有する樹脂フィルムが数多く市販されている。そのような市販品として具体的には、ポリエチレン樹脂フィルム表面に粘着剤が塗布されているサニテクト（（株）サンエー化研製）、ポリエチレンテレフタレート樹脂フィルム表面に粘着剤が塗布されているＥ−マスク（日東電工（株）製）、ポリエチレンテレフタレート樹脂フィルム表面に粘着剤が塗布されているマスタック（藤森工業（株）製）、自己粘着性を有するポリエチレン樹脂からなるトレテック（東レフィルム加工（株）製）などが挙げられる。 As the polarizing plate protective film, many resin films having a surface coated with an adhesive and self-adhesive resin films are commercially available. Specifically, as such a commercial product, sanitect (manufactured by Sanei Kaken Co., Ltd.) in which an adhesive is applied to the surface of the polyethylene resin film, E-mask (in which an adhesive is applied to the surface of the polyethylene terephthalate resin film) Nitto Denko Co., Ltd.), MASTACK (manufactured by Fujimori Kogyo Co., Ltd.) with an adhesive applied to the surface of polyethylene terephthalate resin film, Tretec (manufactured by Toray Film Processing Co., Ltd.) made of self-adhesive polyethylene resin Etc.
　（粘着剤保護フィルム）
　粘着剤保護フィルムは、偏光板の表面に設けられた粘着剤層を保護するためのフィルムである。粘着剤層が保護されずむき出しの場合、偏光板を実際に使用する前に、ごみが付着したり、偏光板が意図しない部分に固着したりすることがある。それを防止するために、粘着剤保護フィルムが用いられる。
　粘着剤保護フィルムは、離型処理されたプラスチックフィルムであれば特に限定されず、例えば、熱可塑性樹脂（ポリエチレンテレフタレート、ポリエチレンナフトレート、ポリエチレン、ポリプロピレンなど）などを加工して得られるフィルムに、シリコーン樹脂などによる離型処理を施したフィルムなどが挙げられる。このような粘着剤保護フィルムとしては、離型フィルムとして市販されているものを使用することができる粘着剤保護フィルムは、通常は１５~８０μｍ程度、好ましくは２０~５０μｍ程度の厚みを有する。 (Adhesive protective film)
The pressure-sensitive adhesive protective film is a film for protecting the pressure-sensitive adhesive layer provided on the surface of the polarizing plate. In the case where the pressure-sensitive adhesive layer is unprotected and exposed, dust may adhere to the polarizing plate or the polarizing plate may adhere to an unintended portion before actually using the polarizing plate. In order to prevent this, a pressure-sensitive adhesive protective film is used.
The adhesive protective film is not particularly limited as long as it is a release-treated plastic film. For example, silicone is applied to a film obtained by processing a thermoplastic resin (polyethylene terephthalate, polyethylene naphthoate, polyethylene, polypropylene, etc.). Examples thereof include a film subjected to a release treatment with a resin or the like. As such an adhesive protective film, a commercially available adhesive protective film that can be used as a release film has a thickness of usually about 15 to 80 μm, preferably about 20 to 50 μm.
　（粘着剤層）
　本発明の偏光板は、粘着剤保護フィルムが積層されている面に、粘着剤層を有する。かかる粘着剤層は、液晶セルと偏光板との貼合に従来より用いられている粘着剤で形成されている。このような粘着剤としては、アクリル系、ゴム系、ウレタン系、シリコーン系、ポリビニルエーテル系などの粘着剤が挙げられる。また、活性エネルギー線硬化型、熱硬化型などの粘着剤を用いてもよい。これらの中でも、透明性、耐候性、耐熱性などに優れるアクリル系樹脂をベースポリマーとしたアクリル系粘着剤が好適である。 (Adhesive layer)
The polarizing plate of this invention has an adhesive layer in the surface where the adhesive protective film is laminated | stacked. This pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive conventionally used for bonding a liquid crystal cell and a polarizing plate. Examples of such an adhesive include acrylic, rubber, urethane, silicone, and polyvinyl ether adhesives. Moreover, you may use adhesives, such as an active energy ray hardening type and a thermosetting type. Among these, an acrylic pressure-sensitive adhesive based on an acrylic resin excellent in transparency, weather resistance, heat resistance and the like as a base polymer is preferable.
　アクリル系粘着剤としては、特に限定されず、例えば（メタ）アクリル酸ブチル、（メタ）アクリル酸エチル、（メタ）アクリル酸イソオクチル、（メタ）アクリル酸２−エチルヘキシルなどの（メタ）アクリル酸エステル系のポリマーや、これらの（メタ）アクリル酸エステルを２種以上含む共重合系のポリマーを、ベースポリマーとする粘着剤が挙げられる。なお、（メタ）アクリルは、「アクリル」または「メタクリル」を意味する。共重合系のポリマーを構成するモノマーとして、好ましくは極性モノマーが含まれている。極性モノマーとしては、カルボキシル基、水酸基、アミド基、アミノ基、エポキシ基などの官能基を有するモノマーが挙げられ、具体的には、（メタ）アクリル酸、（メタ）アクリル酸２−ヒドロキシプロピル、（メタ）アクリル酸ヒドロキシエチル、（メタ）アクリルアミド、Ｎ，Ｎ−ジメチルアミノエチル（メタ）アクリレート、グリシジル（メタ）アクリレートなどが挙げられる。 The acrylic pressure-sensitive adhesive is not particularly limited, and examples thereof include (meth) acrylic acid esters such as butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Examples thereof include pressure-sensitive adhesives in which a base polymer is used as a base polymer or a copolymer polymer containing two or more of these (meth) acrylic acid esters. (Meth) acryl means “acryl” or “methacryl”. As a monomer constituting the copolymer polymer, a polar monomer is preferably included. Examples of the polar monomer include monomers having a functional group such as a carboxyl group, a hydroxyl group, an amide group, an amino group, and an epoxy group. Specifically, (meth) acrylic acid, (meth) acrylic acid 2-hydroxypropyl, Examples include hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, and glycidyl (meth) acrylate.
　アクリル系粘着剤は、単独で使用してもよく、架橋剤と併用してもよい。架橋剤としては、カルボキシル基との間でカルボン酸金属塩を形成する２価以上の多価の金属塩、カルボキシル基とアミド結合を形成するポリアミン化合物、カルボキシル基とエステル結合を形成するポリエポキシ化合物またはポリオール化合物、カルボキシル基と反応してアミド結合を形成するポリイソシアネート化合物などが挙げられる。これらの中でも、ポリイソシアネート化合物が好適に使用される。 The acrylic pressure-sensitive adhesive may be used alone or in combination with a crosslinking agent. As cross-linking agents, divalent or higher polyvalent metal salts that form carboxylic acid metal salts with carboxyl groups, polyamine compounds that form amide bonds with carboxyl groups, polyepoxy compounds that form ester bonds with carboxyl groups Or a polyol compound, the polyisocyanate compound etc. which react with a carboxyl group and form an amide bond are mentioned. Among these, a polyisocyanate compound is preferably used.
　活性エネルギー線硬化型粘着剤とは、紫外線や電子線などの活性エネルギー線の照射により硬化する性質を有する粘着剤のことをいい、活性エネルギー線照射前においても、粘着性を有しておりフィルムなどの被着体に密着し、活性エネルギー線の照射により硬化して密着力の調整が可能な性質を有する。活性エネルギー線硬化型粘着剤としては、紫外線硬化型粘着剤が好ましい。活性エネルギー線硬化型粘着剤は、通常、アクリル系粘着剤と活性エネルギー線重合性化合物とを主成分とする。さらに、架橋剤を添加してもよく、必要に応じて光重合開始剤や光増感剤を添加してもよい。 An active energy ray-curable pressure-sensitive adhesive is a pressure-sensitive adhesive that has a property of being cured by irradiation with active energy rays such as ultraviolet rays and electron beams, and has an adhesive property even before irradiation with active energy rays. It adheres to the adherend such as, and is cured by irradiation with active energy rays, so that the adhesion can be adjusted. As the active energy ray curable adhesive, an ultraviolet curable adhesive is preferable. The active energy ray-curable pressure-sensitive adhesive usually contains an acrylic pressure-sensitive adhesive and an active energy ray-polymerizable compound as main components. Furthermore, a crosslinking agent may be added, and a photopolymerization initiator or a photosensitizer may be added as necessary.
　粘着剤には、架橋剤以外にも、必要に応じて、天然樹脂、合成樹脂、粘着性付与樹脂、酸化防止剤、紫外線吸収剤、染料、顔料、消泡剤、腐食抑制剤、重合開始剤（光重合開始剤など）などの添加剤を添加してもよい。これらの添加剤を用いることによって、粘着剤の粘着力、凝集力、粘性、弾性率、ガラス転移温度などを調整することができる。 In addition to the crosslinking agent, the adhesive may be a natural resin, a synthetic resin, a tackifier resin, an antioxidant, an ultraviolet absorber, a dye, a pigment, an antifoaming agent, a corrosion inhibitor, a polymerization initiator, if necessary. You may add additives, such as (a photoinitiator etc.). By using these additives, the adhesive force, cohesive force, viscosity, elastic modulus, glass transition temperature, etc. of the adhesive can be adjusted.
　粘着剤層は、好ましくは１~４０μｍの厚みを有する。積層板の加工性や耐久性を損なわない範囲で薄く塗るのが好ましく、より良好な加工性を保ち、かつ偏光板の寸法変化を抑える点から、より好ましくは３~２５μｍの厚みを有する。粘着剤層の厚みが薄すぎると粘着性が低下し、厚すぎると粘着剤が積層板からはみ出すなどの不具合を生じやすくなる。 The pressure-sensitive adhesive layer preferably has a thickness of 1 to 40 μm. It is preferable to apply a thin layer within a range that does not impair the workability and durability of the laminate, and more preferably a thickness of 3 to 25 μm from the viewpoint of maintaining better workability and suppressing the dimensional change of the polarizing plate. If the thickness of the pressure-sensitive adhesive layer is too thin, the tackiness is lowered, and if it is too thick, problems such as the pressure-sensitive adhesive sticking out of the laminate are likely to occur.
　（偏光板）
　偏光板は、自然光を直線偏光に変換する機能を有する。一般に偏光板は、偏光子と、偏光子の少なくとも一方の表面に固着された偏光子保護フィルムとが積層されたものであり、必要に応じて他の機能性フィルムや機能性シートも積層されていてもよい。偏光子としては、例えば下記の（ａ）や（ｂ）などが挙げられる。
　（ａ）ポリビニルアルコール（ＰＶＡ）系樹脂、ポリ酢酸ビニル樹脂、エチレン／酢酸ビニル（ＥＶＡ）樹脂、ポリアミド樹脂、ポリエステル系樹脂などのフィルムに、二色性色素を吸着および配向させたもの。
　（ｂ）分子的に配向したポリビニルアルコールフィルム中に、ポリビニルアルコールの二色性脱水生成物（ポリビニレン）の配向した分子鎖を有するポリビニルアルコール／ポリビニレンコポリマー。 (Polarizer)
The polarizing plate has a function of converting natural light into linearly polarized light. In general, a polarizing plate is a laminate of a polarizer and a polarizer protective film fixed to at least one surface of the polarizer, and other functional films and functional sheets are laminated as necessary. May be. Examples of the polarizer include the following (a) and (b).
(A) A film obtained by adsorbing and orienting a dichroic dye on a film of polyvinyl alcohol (PVA) resin, polyvinyl acetate resin, ethylene / vinyl acetate (EVA) resin, polyamide resin, polyester resin, or the like.
(B) A polyvinyl alcohol / polyvinylene copolymer having an oriented molecular chain of a dichroic dehydrated product of polyvinyl alcohol (polyvinylene) in a molecularly oriented polyvinyl alcohol film.
　ポリビニルアルコール系樹脂は、通常、ポリ酢酸ビニル系樹脂をケン化することによって得られる。ケン化度は、通常８５モル％以上、好ましくは９０モル以上、より好ましくは９９~１００モル％である。ポリ酢酸ビニル系樹脂としては、酢酸ビニルの単独重合体であるポリ酢酸ビニルの他、酢酸ビニルと共重合可能な他の単量体との共重合体、例えばエチレン−酢酸ビニル共重合体などが挙げられる。他の単量体としては、例えば、不飽和カルボン酸類、オレフィン類、ビニルエーテル類、不飽和スルホン酸類などが挙げられる。
　また、ポリビニルアルコール系樹脂の分子量は特に限定されず、好ましくは１０００~１００００程度、より好ましくは１５００~５０００程度である。 The polyvinyl alcohol-based resin is usually obtained by saponifying a polyvinyl acetate-based resin. The saponification degree is usually 85 mol% or more, preferably 90 mol or more, more preferably 99 to 100 mol%. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers with other monomers copolymerizable with vinyl acetate, such as ethylene-vinyl acetate copolymer. Can be mentioned. Examples of other monomers include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids.
The molecular weight of the polyvinyl alcohol-based resin is not particularly limited, and is preferably about 1000 to 10000, more preferably about 1500 to 5000.
　さらに、ポリビニルアルコールは変性されていてもよい。変性ポリビニルアルコールとしては、例えば、アルデヒド類で変性されたポリビニルホルマール、ポリビニルアセタール、ポリビニルブチラールなどが挙げられる。
　偏光子製造の開始材料としては、好ましくは２０~１００μｍ、より好ましくは３０~８０μｍの厚みを有する上記のポリビニルアルコール系樹脂の未延伸フィルムが用いられる。フィルムの幅は、工業的には１５００~４０００ｍｍ程度が好ましい。この未延伸フィルムを、例えば、膨潤工程、染色工程、架橋工程、および水洗工程の順に処理し、架橋工程までの工程で一軸延伸を施し、最後に乾燥して偏光子が得られる。偏光子は、通常５~５０μｍ、好ましくは５~３０μｍの厚みを有する。 Furthermore, the polyvinyl alcohol may be modified. Examples of the modified polyvinyl alcohol include polyvinyl formal modified with aldehydes, polyvinyl acetal, polyvinyl butyral, and the like.
As a starting material for producing a polarizer, an unstretched film of the above-mentioned polyvinyl alcohol resin having a thickness of preferably 20 to 100 μm, more preferably 30 to 80 μm is used. Industrially, the width of the film is preferably about 1500 to 4000 mm. This unstretched film is processed in the order of, for example, a swelling process, a dyeing process, a crosslinking process, and a water washing process, subjected to uniaxial stretching in the process up to the crosslinking process, and finally dried to obtain a polarizer. The polarizer usually has a thickness of 5 to 50 μm, preferably 5 to 30 μm.
　染色工程で用いられる二色性色素としては、例えば、ヨウ素や有機染料などが挙げられる。有機染料としては、例えば、レッドＢＲ、レッドＬＲ、レッドＲ、ピンクＬＢ、ルビンＢＬ、ボルドーＧＳ、スカイブルーＬＧ、レモンイエロー、ブルーＢＲ、ブルー２Ｒ、ネイビーＲＹ、グリーンＬＧ、バイオレットＬＢ、バイオレットＢ、ブラックＨ、ブラックＢ、ブラックＧＳＰ、イエロー３Ｇ、イエローＲ、オレンジＬＲ、オレンジ３Ｒ、スカーレットＧＬ、スカーレットＫＧＬ、コンゴーレッド、ブリリアントバイオレットＢＫ、スプラブルーＧ、スプラブルーＧＬ、スプラオレンジＧＬ、ダイレクトスカイブルー、ダイレクトファーストオレンジＳ、ファーストブラックなどが挙げられる。これらの二色性色素は単独で用いてもよく、２種以上を併用してもよい。 Examples of the dichroic dye used in the dyeing process 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. are mentioned. These dichroic dyes may be used alone or in combination of two or more.
　架橋工程で用いられる架橋剤としては、従来公知の物質を使用することができる。例えば、ホウ酸、ホウ砂などのホウ素化合物や、グリオキザール、グルタルアルデヒドなどが挙げられる。これらの架橋剤は単独でもちいてもよく、２種以上を併用してもよい。 Conventionally known substances can be used as the crosslinking agent used in the crosslinking step. Examples thereof include boron compounds such as boric acid and borax, glyoxal, and glutaraldehyde. These crosslinking agents may be used alone or in combination of two or more.
　次に、偏光子保護フィルムについて説明する。偏光子は強度が低く、裂けやすい。偏光子保護フィルムは、かかる偏光子を保護するためのフィルムであり、偏光子の少なくとも一方の面に固着されている。
　偏光子保護フィルムとしては、当該分野で従来より用いられているフィルムが挙げられ、例えば、シクロオレフィン系樹脂フィルム、酢酸セルロース系樹脂フィルム、ポリエステル系樹脂フィルム（例えば、ポリエチレンテレフタレート、ポリエチレンナフタレート、ポリブチレンテレフタレートなど）、ポリカーボネート系樹脂フィルム、アクリル系樹脂フィルム、ポリプロピレン系樹脂フィルムなどが挙げられる。 Next, the polarizer protective film will be described. Polarizers have low strength and are easy to tear. The polarizer protective film is a film for protecting such a polarizer, and is fixed to at least one surface of the polarizer.
Examples of the polarizer protective film include films conventionally used in this field. For example, cycloolefin resin films, cellulose acetate resin films, polyester resin films (for example, polyethylene terephthalate, polyethylene naphthalate, poly Butylene terephthalate), polycarbonate resin film, acrylic resin film, polypropylene resin film, and the like.
　偏光子保護フィルムは、透明で優れた耐薬品性を有するものが好ましく、酢酸セルロース系樹脂フィルムがより好ましい。酢酸セルロース系樹脂は、セルロースの部分または完全酢酸エステル化物であり、例えば、トリアセチルセルロース（ＴＡＣ）、ジアセチルセルロース、セルロースアセテートプロピオネートなどが挙げられる。
　酢酸セルロース系樹脂フィルムは市販されており、例えば、フジタック（登録商標）ＴＤ８０（富士フィルム（株）製）、フジタック（登録商標）ＴＤ８０ＵＦ（富士フィルム（株）製）、フジタック（登録商標）ＴＤ８０ＵＺ（富士フィルム（株）製）、ＫＣ８ＵＸ２Ｍ（コニカミノルタオプト（株）製）、ＫＣ４ＵＹ（コニカミノルタオプト（株）製）などが挙げられる。 The polarizer protective film is preferably transparent and has excellent chemical resistance, and more preferably a cellulose acetate-based resin film. The cellulose acetate-based resin is a part of cellulose or a complete acetate ester, and examples thereof include triacetyl cellulose (TAC), diacetyl cellulose, and cellulose acetate propionate.
Cellulose acetate-based resin films are commercially available. For example, Fujitac (registered trademark) TD80 (Fuji Film Co., Ltd.), Fujitac (registered trademark) TD80UF (Fuji Film Co., Ltd.), Fujitac (registered trademark) TD80UZ ( Fuji Film Co., Ltd.), KC8UX2M (Konica Minolta Opto Co., Ltd.), KC4UY (Konica Minolta Opto Co., Ltd.) and the like.
　偏光子保護フィルムは、偏光子の少なくとも一方の表面に固着されていればよい。偏光子の両面に偏光子保護フィルムを固着する場合、両面とも同じ偏光子保護フィルムであってもよく、異なる偏光子保護フィルムであってもよい。例えば、偏光子の両面にトリアセチルセルロースを固着してもよく、片面にトリアセチルセルロースを固着して残りの面に他の偏光子保護フィルムを固着してもよい。他の偏光子保護フィルムとしては、特に限定されないが、好ましくはシクロオレフィン系樹脂フィルムが用いられる。 The polarizer protective film only needs to be fixed to at least one surface of the polarizer. When fixing a polarizer protective film on both surfaces of a polarizer, the same polarizer protective film may be sufficient as both surfaces, and a different polarizer protective film may be sufficient. For example, triacetyl cellulose may be fixed on both sides of the polarizer, or triacetyl cellulose may be fixed on one side and another polarizer protective film may be fixed on the remaining side. Although it does not specifically limit as another polarizer protective film, Preferably a cycloolefin type-resin film is used.
　シクロオレフィン系樹脂は市販されており、例えば、Ｔｏｐａｓ（登録商標）（Ｔｉｃｏｎａ社製）、アートン（登録商標）（ＪＳＲ（株）製）、ゼオノア（ＺＥＯＮＯＲ）（登録商標）（日本ゼオン（株）製）、ゼオネックス（ＺＥＯＮＥＸ）（登録商標）（日本ゼオン（株）製）、アルペ（登録商標）（三井化学（株）製）などが挙げられる。
　シクロオレフィン樹脂をフィルムに製膜する際には、溶剤キャスト法、溶融押出法などの公知の方法が適宜用いられる。また、例えばエスシーナ（登録商標）（積水化学工業（株）製）、ＳＣＡ４０（積水化学工業（株）製）、ゼオノア（登録商標）フィルム（（株）オプテス製）など、予め製膜されたシクロオレフィン系樹脂フィルムの市販品を用いてもよい。 Cycloolefin resins are commercially available. For example, Topas (registered trademark) (manufactured by Ticona), Arton (registered trademark) (manufactured by JSR Corporation), ZEONOR (registered trademark) (Nippon ZEON Corporation). ZEONEX (registered trademark) (manufactured by Nippon Zeon Co., Ltd.), Alpe (registered trademark) (manufactured by Mitsui Chemicals, Inc.), and the like.
When the cycloolefin 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, for example, ESCINA (registered trademark) (manufactured by Sekisui Chemical Co., Ltd.), SCA40 (manufactured by Sekisui Chemical Co., Ltd.), Zeonor (registered trademark) film (manufactured by Optes Co., Ltd.), etc. A commercially available olefin resin film may be used.
　偏光子保護フィルムは、通常１０~１５０μｍ程度、好ましくは２０~１００μｍ程度の厚みを有する。 The polarizer protective film usually has a thickness of about 10 to 150 μm, preferably about 20 to 100 μm.
　（位相差板）
　偏光板を製造する際に、偏光子および偏光子保護フィルムとともに、必要に応じて積層する機能性フィルムまたは機能性シートとして、位相差板がよく用いられる。位相差板は、液晶パネルや液晶表示装置に要求される特性に応じて採用される。 (Phase difference plate)
When producing a polarizing plate, a retardation plate is often used as a functional film or a functional sheet to be laminated as necessary together with a polarizer and a polarizer protective film. The phase difference plate is employed according to the characteristics required for a liquid crystal panel or a liquid crystal display device.
　偏光板が楕円偏光板として用いられる場合、位相差板としては、例えば１／４波長板を備える。また、偏光板が直線偏光板として用いられる場合、位相差板としては、例えば、光学補償機能を有する二軸性位相差フィルム、表面保護機能を有する無配向性フィルムなどが採用される。
　１／４波長板とは、可視光の波長領域（３８０~７８０ｎｍ）のいずれかの光に対して、ほぼ１／４波長（９０度）の位相差を示す板（フィルム）であり、直線偏光と円偏光とを相互に変換する機能を有するとともに、液晶セルの視野角を補償する機能を有している。 When the polarizing plate is used as an elliptical polarizing plate, for example, a quarter wave plate is provided as the retardation plate. Moreover, when a polarizing plate is used as a linear polarizing plate, as a phase difference plate, the biaxial phase difference film which has an optical compensation function, the non-orientation film which has a surface protection function, etc. are employ | adopted, for example.
A quarter-wave plate is a plate (film) that exhibits a phase difference of almost ¼ wavelength (90 degrees) with respect to any light in the wavelength region of visible light (380 to 780 nm). And a function of mutually converting circularly polarized light and a function of compensating the viewing angle of the liquid crystal cell.
　位相差板を構成する材料としては、特に限定されず、例えば（メタ）アクリル系樹脂（メタクリル酸メチル系樹脂など）、オレフィン系樹脂、ポリ塩化ビニル系樹脂、セルロース系樹脂、スチレン系樹脂、アクリロニトリル−ブタジエン−スチレン系共重合体樹脂（ＡＢＳ樹脂）、アクリロニトリル−スチレン系共重合体樹脂（ＡＳ樹脂）、ポリ酢酸ビニル系樹脂、ポリ塩化ビニリデン系樹脂、ポリアミド系樹脂、ポリアセタール系樹脂、ポリカーボネート系樹脂、変性ポリフェニレンエーテル樹脂、ポリエステル系樹脂（ポリエチレンテレフタレート、ポリブチレンテレフタレートなど）、ポリスルホン系樹脂、ポリエーテルスルホン系樹脂、ポリアリレート系樹脂、ポリアミドイミド系樹脂、ポリイミド系樹脂、エポキシ系樹脂、オキセタン系樹脂などが挙げられる。なお、これらの樹脂には、透明性や固着性を阻害しない範囲で、添加物が含まれていてもよい。 The material constituting the retardation plate is not particularly limited. For example, a (meth) acrylic resin (such as a methyl methacrylate resin), an olefin resin, a polyvinyl chloride resin, a cellulose resin, a styrene resin, or acrylonitrile. -Butadiene-styrene copolymer resin (ABS resin), acrylonitrile-styrene copolymer resin (AS resin), polyvinyl acetate resin, polyvinylidene chloride resin, polyamide resin, polyacetal resin, polycarbonate resin , Modified polyphenylene ether resin, polyester resin (polyethylene terephthalate, polybutylene terephthalate, etc.), polysulfone resin, polyethersulfone resin, polyarylate resin, polyamideimide resin, polyimide resin, epoxy resin, oxygen Such as single-based resin and the like. These resins may contain additives within a range that does not impair transparency and adhesion.
　位相差板を用いる場合、位相差板は１層であってもよく、２層以上を構成していてもよい。２層以上の位相差板を積層させる場合、同じ位相差板を用いても異なる位相差板を用いてもよいが、通常、異なる位相差板が用いられる。なお、同じ位相差板を用いる場合は、通常それぞれの軸角度を変えて用いられるが、同じ軸角度で用いてもよい。位相差板は、通常１０~１００μｍ程度、好ましくは２０~８０μｍ程度の厚みを有する。 When using a phase difference plate, the phase difference plate may be a single layer or two or more layers. When two or more retardation plates are stacked, the same retardation plate or different retardation plates may be used, but different retardation plates are usually used. In addition, when using the same phase difference plate, it is normally used by changing each axial angle, but you may use it with the same axial angle. The retardation plate usually has a thickness of about 10 to 100 μm, preferably about 20 to 80 μm.
　（積層工程）
　一方の表面に偏光板保護フィルムが積層され、他方の表面に粘着剤保護フィルムが積層された偏光性積層板は、上述の偏光板保護フィルム、粘着剤保護フィルム、偏光子、偏光子保護フィルム、および必要に応じて他の機能性フィルムまたは機能性シートを積層して得た積層体であり、切断して偏光板を得る前の原反となる。
　偏光性積層板において、偏光子、偏光子保護フィルムおよび他の機能性フィルムまたは機能性シートは、一般に接着剤または粘着剤で固着されている。接着剤および粘着剤は、偏光板としての機能を阻害しないものであれば限定されず、例えば、ポリビニルアルコール系樹脂、エポキシ系樹脂、ウレタン系樹脂、シアノアクリレート系樹脂、アクリルアミド系樹脂などを成分とする接着剤および粘着剤が挙げられる。 (Lamination process)
A polarizing laminate having a polarizing plate protective film laminated on one surface and an adhesive protective film laminated on the other surface is the polarizing plate protective film, adhesive protective film, polarizer, polarizer protective film described above, And it is the laminated body obtained by laminating | stacking another functional film or a functional sheet as needed, and becomes a raw fabric before cut | disconnecting and obtaining a polarizing plate.
In a polarizing laminate, a polarizer, a polarizer protective film, and another functional film or functional sheet are generally fixed with an adhesive or a pressure-sensitive adhesive. The adhesive and the pressure-sensitive adhesive are not limited as long as they do not inhibit the function as a polarizing plate. For example, polyvinyl alcohol resin, epoxy resin, urethane resin, cyanoacrylate resin, acrylamide resin and the like are used as components. Adhesives and pressure-sensitive adhesives.
　好ましい接着剤の１つとして、無溶剤型の接着剤が挙げられる。無溶剤型の接着剤とは、有意量の溶剤を含まず、活性エネルギー線（例えば、紫外線、可視光線、電子線、Ｘ線など）の照射により反応硬化する硬化性化合物（モノマー、オリゴマーなど）を含み、硬化性化合物の硬化によって固着機能を発揮する接着剤のことである。このような接着剤には、硬化性化合物とともに、通常、重合開始剤が含まれる。 One preferred adhesive is a solventless adhesive. Solventless adhesives do not contain a significant amount of solvent and are curable compounds (monomers, oligomers, etc.) that are reactively cured by irradiation with active energy rays (for example, ultraviolet rays, visible rays, electron beams, X-rays, etc.). And an adhesive that exhibits a fixing function by curing of the curable compound. Such an adhesive usually contains a polymerization initiator together with a curable compound.
　前記原反となる積層体は、所望の偏光板の用途に応じて構成され、例えば、「偏光板保護フィルム／偏光板（偏光子保護フィルム／偏光子）／粘着剤層／粘着剤保護フィルム」、「偏光板保護フィルム／偏光板（偏光子保護フィルム／偏光子／位相差板）／粘着剤層／粘着剤保護フィルム」、「偏光板保護フィルム／偏光板（偏光子保護フィルム／偏光子／第１の位相差板／第２の位相差板）／粘着剤層／粘着剤保護フィルム」、「偏光板保護フィルム／偏光板（偏光子保護フィルム／偏光子／偏光子保護フィルム）／粘着剤層／粘着剤保護フィルム」、「偏光板保護フィルム／偏光板（偏光子保護フィルム／偏光子／偏光子保護フィルム／位相差板）／粘着剤層／粘着剤保護フィルム」、「偏光板保護フィルム／偏光板（偏光子保護フィルム／偏光子／偏光子保護フィルム／第１の位相差板／第２の位相差板）／粘着剤層／粘着剤保護フィルム」などの積層構造を有する。なお、偏光子、偏光子保護フィルムおよび位相差板を固着する接着剤または粘着剤の記載は省略している。 The laminate as the raw fabric is configured according to the desired use of the polarizing plate. For example, “polarizing plate protective film / polarizing plate (polarizer protective film / polarizer) / adhesive layer / adhesive protective film” , "Polarizing plate protective film / Polarizing plate (Polarizer protective film / Polarizer / Phase difference plate) / Adhesive layer / Adhesive protective film", "Polarizing plate protective film / Polarizer (Polarizer protective film / Polarizer / "First retardation plate / second retardation plate) / adhesive layer / adhesive protective film", "polarizing plate protective film / polarizing plate (polarizer protective film / polarizer / polarizer protective film) / adhesive Layer / adhesive protective film ”,“ polarizing plate protective film / polarizing plate (polarizer protective film / polarizer / polarizer protective film / retardation plate) / adhesive layer / adhesive protective film ”,“ polarizing plate protective film ” / Polarizing plate (polarizer protection film) N / a including a polarizer / polarizer protective film / first retardation plate / the second retardation plate) / adhesive layer / adhesive protective film "stack structure such as. In addition, description of the adhesive agent or adhesive which adheres a polarizer, a polarizer protective film, and a phase difference plate is abbreviate | omitted.
　このようにして得られた積層体（原反）の厚みは、製品である偏光板の用途に応じて適宜設定され、通常１００~６００μｍ程度、好ましくは１５０~４００μｍ程度である。
　積層体（原反）は通常、ロールに巻かれた長尺のシートを原料として、それに対して連続的または間欠的に種々の処理を行って、製造される。そして、本発明においては、通常、積層体（原反）の製造のいずれかの段階であって、切断工程を実施する前に、短尺の積層体となるよう切断される。得られる短尺の積層体（原反）は、目的とする偏光板よりも大きく、例えば４枚~８０枚といった複数の偏光板を得ることの出来る大きさである。 The thickness of the laminate (raw material) thus obtained is appropriately set according to the use of the polarizing plate as a product, and is usually about 100 to 600 μm, preferably about 150 to 400 μm.
A laminate (raw fabric) is usually produced by using a long sheet wound on a roll as a raw material, and subjecting it to various treatments continuously or intermittently. And in this invention, it is a stage of manufacture of a laminated body (original fabric) normally, Comprising: Before implementing a cutting process, it cut | disconnects so that it may become a short laminated body. The obtained short laminate (raw material) is larger than the target polarizing plate, and has a size that can obtain a plurality of polarizing plates, for example, 4 to 80 sheets.
　（切断工程）
　次に、本発明の製造方法における切断工程を説明する。
　切断工程は、上記積層体（原反）を切断して、両表面に保護フィルムが積層された所定寸法の偏光板を得る工程である。本発明の製造方法では、切断工程において、積層体（原反）を、その粘着剤保護フィルム側の表面に刃を当てて、切断する。粘着剤保護フィルム側の表面に刃を当てて、積層体（原反）を切断することによって、水分が付着してもクラックが生じにくい偏光板を得ることができる。後述する比較例で示すように、積層体（原反）を、偏光板保護フィルム側の表面に刃を当てて、切断すると、水分の付着によりクラックが発生しやすい。このように、積層体（原反）を切断する際に、どちらの表面に刃を当てるかによって、水分の付着によるクラックの発生のしやすさが異なってくるのである。
　なお、ここでいう「粘着剤保護フィルム側の表面」とは、偏光子の層から見て、粘着剤保護フィルムの層のある側の最表面を意味し、積層体（原反）を直接切断する場合には粘着剤保護フィルムの表面であり、粘着剤保護フィルムが上側となるように置いた積層体（原反）の上に、他の物体（例えば後述の被覆シート）を乗せて切断する場合には、当該物体の上表面である。 (Cutting process)
Next, the cutting process in the manufacturing method of this invention is demonstrated.
A cutting process is a process of cutting the said laminated body (raw material), and obtaining the polarizing plate of the predetermined dimension by which the protective film was laminated | stacked on both surfaces. In the production method of the present invention, in the cutting step, the laminate (raw material) is cut by applying a blade to the surface of the pressure-sensitive adhesive protective film. By applying a blade to the surface on the pressure-sensitive adhesive protective film side and cutting the laminate (raw material), a polarizing plate that is less prone to crack even when moisture adheres can be obtained. As shown in a comparative example to be described later, when the laminate (raw material) is cut by applying a blade to the surface on the polarizing plate protective film side, cracks are likely to occur due to adhesion of moisture. In this way, when cutting the laminated body (raw fabric), the ease of occurrence of cracks due to the adhesion of moisture differs depending on which surface the blade is applied to.
As used herein, “surface on the side of the pressure-sensitive adhesive protective film” means the outermost surface on the side where the layer of the pressure-sensitive adhesive protective film is present, as viewed from the polarizer layer, and the laminate (raw material) is directly cut. When it does, it is the surface of the pressure-sensitive adhesive protective film, and is cut by placing another object (for example, a covering sheet described later) on the laminate (original fabric) placed so that the pressure-sensitive adhesive protective film is on the upper side. In the case, it is the upper surface of the object.
　上述の通り、偏光板保護フィルムに欠陥があると、液晶パネル製造工場における欠陥検査で、得られた貼合品（液晶パネル）全体が廃棄処分となったりするので、偏光板の製造時には、偏光板保護フィルムに傷などが付かないよう、細心の注意が必要である。一方で、液晶セルに偏光板を貼り付ける際に剥がされる粘着剤保護フィルムについては、少々の傷は許容される。そこで、本発明における偏光板の製造時には、従来通り、通常は偏光板保護フィルムが上面側となるよう取り扱い、切断工程において、積層体（原反）の上下を逆に設置して、切断するのが好ましい。この切断工程においては、下面となっている偏光板保護フィルムに傷が付かないよう、細心の注意を払うべきである。 As described above, if there is a defect in the polarizing plate protective film, the entire bonded product (liquid crystal panel) obtained in the defect inspection at the liquid crystal panel manufacturing factory will be disposed of. Extreme care must be taken to prevent scratches on the protective film. On the other hand, for the pressure-sensitive adhesive protective film peeled off when the polarizing plate is attached to the liquid crystal cell, a slight scratch is allowed. Therefore, at the time of manufacturing the polarizing plate in the present invention, as usual, it is usually handled so that the polarizing plate protective film is on the upper surface side. Is preferred. In this cutting step, extreme care should be taken so that the polarizing plate protective film on the lower surface is not damaged.
　また、積層体（原反）を切断する際、表面に汚れ（糊汚れなど）を生じにくくするために、粘着剤保護フィルムの上面を被覆シートで覆って、切断するのが好ましい。
　被覆シートとしては、積層体（原反）とともに切断され得る材質のシートであれば限定されず、例えば、樹脂製のフィルム（ポリエチレン製フィルム、ポリプロピレン製フィルムなど）、布（織布、不織布など）、紙などが挙げられる。粘着剤保護フィルムの上面を被覆シートで覆う際には、粘着剤保護フィルムの上面に被覆シートを乗せ、粘着剤保護フィルムと被覆シートとの間の気泡を除去するのが好ましい。 Further, when cutting the laminate (raw material), it is preferable to cut the laminate by covering the upper surface of the pressure-sensitive adhesive protective film with a cover sheet in order to make it difficult to cause dirt (such as glue stains) on the surface.
The covering sheet is not limited as long as it is a sheet made of a material that can be cut together with the laminate (raw material). For example, a resin film (polyethylene film, polypropylene film, etc.), cloth (woven cloth, non-woven cloth, etc.) And paper. When covering the upper surface of the pressure-sensitive adhesive protective film with the cover sheet, it is preferable to place the cover sheet on the upper surface of the pressure-sensitive adhesive protective film and remove bubbles between the pressure-sensitive adhesive protective film and the cover sheet.
　積層体（原反）の切断は、従来より用いられている切断機で行われ、特に限定されない。例えば、バッチ式で行う場合、切断機に応じた大きさ（通常５００ｍｍ×５００ｍｍ~１０００ｍｍ×１０００ｍｍ程度）の積層体（原反）を作製し、粘着剤保護フィルムの面を上にして、積層体（原反）を切断機に固定し、必要に応じて被覆フィルムで覆って、所望の寸法に切断すればよい。なお、本発明の製造方法では、積層体（原反）を粘着剤保護フィルム側の表面に刃を当てて切断するため、切断に用いる刃としては、上下運動によって切断する刃（いわゆる、ギロチン刃）が好ましく採用される。 The cutting of the laminate (raw material) is performed with a conventionally used cutting machine, and is not particularly limited. For example, when it is performed in a batch mode, a laminate (raw material) having a size (usually about 500 mm x 500 mm to 1000 mm x 1000 mm) according to the cutting machine is prepared, and the laminate is placed with the adhesive protective film face up. The (raw material) may be fixed to a cutting machine, covered with a coating film as necessary, and cut to a desired dimension. In the production method of the present invention, the laminate (raw material) is cut by applying a blade to the surface on the pressure-sensitive adhesive protective film side, so that the blade used for cutting is a blade that is cut by vertical movement (so-called guillotine blade) ) Is preferably employed.
　以下、実施例および比較例を挙げて本発明を具体的に説明するが、本発明はこれらの実施例に限定されるものではない。 Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these examples.
　（実施例１）
　長尺のポリビニルアルコールにヨウ素を吸着および配向させた偏光子（厚み２９μｍ）の片面に、表面にハードコート層を有するトリアセチルセルロース製の偏光子保護フィルム（厚み４４μｍ）を、ポリビニルアルコール系樹脂接着剤で接着した。偏光子保護フィルムの表面に偏光板保護フィルムを貼合した。用いた偏光板保護フィルムは、アクリル系粘着剤が塗布されたポリエチレンテレフタレート樹脂フィルム（厚み４９μｍ）である。そして、偏光子の他方の面に、１５μｍの厚みとなるようにアクリル系粘着剤を塗布して積層体Ａを得た。 (Example 1)
A polarizer protective film (thickness 44 μm) made of triacetyl cellulose having a hard coat layer on one surface of a polarizer (thickness 29 μm) in which iodine is adsorbed and oriented on a long polyvinyl alcohol is bonded to a polyvinyl alcohol resin. Glued with agent. A polarizing plate protective film was bonded to the surface of the polarizer protective film. The polarizing plate protective film used is a polyethylene terephthalate resin film (thickness 49 μm) coated with an acrylic adhesive. And the acrylic adhesive was apply | coated to the other surface of a polarizer so that it might be set to 15 micrometers, and the laminated body A was obtained.
　ノルボルネン系樹脂の延伸フィルムからなる面内位相差が２７０ｎｍの位相差板（住友化学（株）製、スミカライトＳＥＳ４３０２７０、厚み３３μｍ）の片面に、５μｍの厚みとなるようにアクリル系粘着剤を塗布した。この面内位相差が２７０ｎｍの位相差板を「第１の位相差板」と呼ぶこととする。
　第１の位相差板の粘着剤が塗布されていない面に、上記積層板Ａのアクリル系粘着剤が塗布された面を貼合した。 An acrylic pressure-sensitive adhesive is applied to one surface of a retardation film (Sumitomo Chemical Co., Ltd., SUMIKALITE SES430270, thickness 33 μm) made of a stretched film of norbornene resin and having an in-plane retardation of 270 nm. did. This retardation plate having an in-plane retardation of 270 nm is referred to as a “first retardation plate”.
The surface where the acrylic adhesive of the said laminated board A was apply | coated was bonded to the surface where the adhesive of the 1st phase difference plate was not apply | coated.
　さらに、面内位相差が１４０ｎｍの位相差板（住友化学（株）製、スミカライトＳＥＳ４３０１４０、厚み２８μｍ）の片面に、１５μｍの厚みとなるようにアクリル系粘着剤を塗布して、粘着剤層を形成した。この面内位相差が１４０ｎｍの位相差板を「第２の位相差板」と呼ぶこととする。この第２の位相差板に形成した粘着剤層の上に、ポリエチレンテレフタレート樹脂で形成された粘着剤保護フィルム（厚み３８μｍ）を貼合した。こうして得られた“粘着剤保護フィルムが貼合された第２の位相差板”の粘着剤層が形成されていない側の面に、上記“積層板Ａが貼合された第１の位相差板”のアクリル系粘着剤が塗布された面を貼合した。
　このようにして各層を積層して、得られた積層板を切って、「偏光板保護フィルム／偏光子保護フィルム／偏光子／アクリル系粘着剤／第１の位相差板／アクリル系粘着剤／第２の位相差板／粘着剤層／粘着剤保護フィルム」の積層構造を有する積層体（原反）（８００ｍｍ×５００ｍｍ、厚み２５６μｍ）を得た。 Furthermore, an acrylic pressure-sensitive adhesive was applied to one surface of a retardation plate (Sumitomo Chemical Co., Ltd., Sumikalite SES430140, thickness 28 μm) having an in-plane retardation of 140 nm, and a pressure-sensitive adhesive layer. Formed. The retardation plate having an in-plane retardation of 140 nm is referred to as a “second retardation plate”. On the pressure-sensitive adhesive layer formed on the second retardation plate, a pressure-sensitive adhesive protective film (thickness 38 μm) formed of polyethylene terephthalate resin was bonded. On the surface of the “second retardation plate with the adhesive protective film bonded” thus obtained, the surface on which the adhesive layer is not formed, the above-mentioned “first retardation with the laminate A bonded”. The surface of the “plate” on which the acrylic adhesive was applied was bonded.
Each layer was laminated in this manner, and the obtained laminated plate was cut, and “polarizing plate protective film / polarizer protective film / polarizer / acrylic adhesive / first retardation plate / acrylic adhesive / A laminate (raw material) (800 mm × 500 mm, thickness 256 μm) having a laminated structure of “second retardation plate / adhesive layer / adhesive protective film” was obtained.
　次いで、得られた積層体（原反）を、粘着剤保護フィルムが上面となるように切断機の当て板の上に載せて、端部をテープで固定した。テープで固定した積層体（原反）の上をポリエチレン製フィルムで覆って、手で押圧することにより、粘着剤保護フィルムとポリエチレン製フィルムとの間にできた気泡を除去した後に、ギロチン刃をポリエチレン製フィルムに当てて、積層体（原反）を切断し、９０ｍｍ×５１ｍｍの偏光板を得た。
　得られた偏光板を、８０℃で１時間乾燥し、乾燥後、２３℃で湿度５５％ＲＨの条件下に１５分間静置した。次いで、偏光板を水（２３℃）に３０分間浸漬し、クラックの有無をルーペおよび顕微鏡を用いて観察したが、クラックは全く発生していなかった。 Next, the obtained laminate (raw fabric) was placed on a cutting plate of a cutting machine so that the pressure-sensitive adhesive protective film was on the upper surface, and the ends were fixed with tape. Cover the laminate (raw fabric) fixed with tape with a polyethylene film and press it with your hand to remove air bubbles between the adhesive protective film and the polyethylene film. The laminated body (raw material) was cut on a polyethylene film to obtain a 90 mm × 51 mm polarizing plate.
The obtained polarizing plate was dried at 80 ° C. for 1 hour, dried, and then allowed to stand at 23 ° C. and 55% humidity for 15 minutes. Next, the polarizing plate was immersed in water (23 ° C.) for 30 minutes, and the presence or absence of cracks was observed using a magnifying glass and a microscope, but no cracks were generated.
　（実施例２）
　実施例１で得られた積層体（原反）を、ポリエチレン製フィルムで覆わずに切断したこと以外は、実施例１と同様にして偏光板を得た。
　得られた偏光板について、実施例１と同様の手順でクラックの有無を観察したが、クラックは全く発生していなかった。 (Example 2)
A polarizing plate was obtained in the same manner as in Example 1 except that the laminate (raw material) obtained in Example 1 was cut without being covered with a polyethylene film.
About the obtained polarizing plate, although the presence or absence of the crack was observed in the procedure similar to Example 1, the crack did not generate | occur | produce at all.
　（比較例１）
　実施例１で得られた積層体（原反）を、偏光板保護フィルムが上面となるように切断機の当て板の上に載せ、かつポリエチレン製フィルムで覆わずに切断したこと以外は、実施例１と同様にして偏光板を得た。
　得られた偏光板について、実施例１と同様の手順でルーペおよび顕微鏡を用いてクラックの有無を観察したところ、偏光板の周縁部に微細なクラックが多数発生していた。 (Comparative Example 1)
Except that the laminate (raw material) obtained in Example 1 was placed on a backing plate of a cutting machine so that the polarizing plate protective film was on the upper surface, and was cut without being covered with a polyethylene film. A polarizing plate was obtained in the same manner as in Example 1.
About the obtained polarizing plate, when the presence or absence of the crack was observed using the loupe and the microscope in the same procedure as Example 1, many fine cracks generate | occur | produced in the peripheral part of the polarizing plate.
　本発明の製造方法で得られた偏光板は、水分が付着してもクラックが生じにくく、例えば、携帯電話機、スマートフォンなどの携帯情報端末などに用いられる。 The polarizing plate obtained by the production method of the present invention is hardly cracked even when moisture adheres, and is used for, for example, a portable information terminal such as a mobile phone or a smartphone.

Claims (4)

  1. 　一方の表面に偏光板保護フィルムが積層され、他方の表面に粘着剤保護フィルムが積層された偏光性積層板を、その前記粘着剤保護フィルム側の表面に刃を当てて、所定の大きさとなるように切断することにより、両表面に保護フィルムが積層された偏光板を製造する方法。 A polarizing laminate having a polarizing plate protective film laminated on one surface and a pressure-sensitive adhesive protective film laminated on the other surface is applied to the surface on the pressure-sensitive adhesive protective film side to obtain a predetermined size. The method of manufacturing the polarizing plate by which the protective film was laminated | stacked on both surfaces by cut | disconnecting like this.
  2. 　前記偏光性積層板を切断する際、前記粘着剤保護フィルムの上面が被覆シートで覆われている、請求項１に記載の方法。 The method according to claim 1, wherein when the polarizing laminate is cut, an upper surface of the pressure-sensitive adhesive protective film is covered with a covering sheet.
  3. 　前記偏光板が、偏光子と、該偏光子の少なくとも一方の表面に固着された保護膜とで形成されている、請求項１または２に記載の方法。 The method according to claim 1 or 2, wherein the polarizing plate is formed of a polarizer and a protective film fixed to at least one surface of the polarizer.
  4. 　前記偏光板が、偏光子と、該偏光子の少なくとも一方の表面に固着された保護膜と、少なくとも１つの位相差板とで形成されている、請求項１または２に記載の方法。 3. The method according to claim 1, wherein the polarizing plate is formed of a polarizer, a protective film fixed to at least one surface of the polarizer, and at least one retardation plate.
PCT/JP2014/061926 2013-04-22 2014-04-22 Method for manufacturing polarizing plate WO2014175462A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
CN201480022243.3A CN105122102A (en) 2013-04-22 2014-04-22 Method for manufacturing polarizing plate
JP2015513869A JPWO2014175462A1 (en) 2013-04-22 2014-04-22 Manufacturing method of polarizing plate
KR1020157030254A KR20160000459A (en) 2013-04-22 2014-04-22 Method for manufacturing polarizing plate

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2013-089013 2013-04-22
JP2013089013 2013-04-22

Publications (1)

Publication Number Publication Date
WO2014175462A1 true WO2014175462A1 (en) 2014-10-30

Family

ID=51792021

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2014/061926 WO2014175462A1 (en) 2013-04-22 2014-04-22 Method for manufacturing polarizing plate

Country Status (4)

Country Link
JP (1) JPWO2014175462A1 (en)
KR (1) KR20160000459A (en)
CN (1) CN105122102A (en)
WO (1) WO2014175462A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2022000694A (en) * 2015-12-25 2022-01-04 日東電工株式会社 Polarizing film with pressure-sensitive adhesive layer, and image display device

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005224935A (en) * 2004-01-15 2005-08-25 Nitto Denko Corp Laminated sheet machining method, laminated sheet machining device, laminated sheet, optical element, and image display device
JP2008058599A (en) * 2006-08-31 2008-03-13 Sumitomo Chemical Co Ltd Method of manufacturing composite polarizing plate product chip

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003195250A (en) * 2001-12-28 2003-07-09 Optrex Corp Manufacturing method for liquid crystal display element
JP4543776B2 (en) * 2004-06-24 2010-09-15 住友化学株式会社 Retardation plate and composite polarizing plate, manufacturing method thereof, and liquid crystal display device
JP2012053078A (en) * 2010-08-31 2012-03-15 Sumitomo Chemical Co Ltd Method for manufacturing polarizing plate

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005224935A (en) * 2004-01-15 2005-08-25 Nitto Denko Corp Laminated sheet machining method, laminated sheet machining device, laminated sheet, optical element, and image display device
JP2008058599A (en) * 2006-08-31 2008-03-13 Sumitomo Chemical Co Ltd Method of manufacturing composite polarizing plate product chip

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2022000694A (en) * 2015-12-25 2022-01-04 日東電工株式会社 Polarizing film with pressure-sensitive adhesive layer, and image display device

Also Published As

Publication number Publication date
JPWO2014175462A1 (en) 2017-02-23
CN105122102A (en) 2015-12-02
KR20160000459A (en) 2016-01-04

Similar Documents

Publication Publication Date Title
JP5082480B2 (en) Thin polarizing plate and image display device using the same
JP5930636B2 (en) Polarizer
KR102196372B1 (en) Polarization plate set and liquid crystal display panel integrated with front plate
JP5332599B2 (en) Polarizing plate, manufacturing method thereof, and composite polarizing plate using the same
KR101819787B1 (en) Composite polarizing plate and liquid crystal display device
KR102457358B1 (en) Set of polarizing plates and front-plate-integrated liquid crystal display panel
JP6862662B2 (en) Polarizing plate, polarizing plate with adhesive, and liquid crystal display device
KR102362343B1 (en) Optical film with adhesive layer
JP5416545B2 (en) Method for producing laminated film
KR102443686B1 (en) Manufacturing method of optical laminate and display device
JP2010262155A (en) Composite polarizing plate
KR101757062B1 (en) Polarizing plate and liquid crystal display device
KR102535072B1 (en) Polarizing plate and liquid crystal display device
JP2010122487A (en) Polarizing plate having high elasticity adhesive layer and image display device using the same
JP2019191551A (en) Laminate body
JP2008197310A (en) Thin polarizing plate, composite polarizing plate, image display device, and method for manufacturing composite polarizing plate
JP6323477B2 (en) Polarizing plate set and LCD panel
TWI767017B (en) Polarizing plate with protective film
JP5878746B2 (en) Composite polarizing plate set, liquid crystal panel and liquid crystal display device
JP2017156399A (en) Set of polarizing plates and liquid crystal panel
JP2010026484A (en) Polarizing plate for ips mode liquid crystal display device, and ips mode liquid crystal display device
JP6181804B2 (en) Polarizer
KR20170113168A (en) Optical film and polarizing plate
WO2014175462A1 (en) Method for manufacturing polarizing plate
KR20220006528A (en) Optical laminate and display device

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 201480022243.3

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14788167

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2015513869

Country of ref document: JP

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 20157030254

Country of ref document: KR

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14788167

Country of ref document: EP

Kind code of ref document: A1