WO2013146163A1 - 偏光板の製造方法および製造装置 - Google Patents

偏光板の製造方法および製造装置 Download PDF

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Publication number
WO2013146163A1
WO2013146163A1 PCT/JP2013/056269 JP2013056269W WO2013146163A1 WO 2013146163 A1 WO2013146163 A1 WO 2013146163A1 JP 2013056269 W JP2013056269 W JP 2013056269W WO 2013146163 A1 WO2013146163 A1 WO 2013146163A1
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Prior art keywords
ultraviolet
optical film
film
polarizing plate
bonding
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PCT/JP2013/056269
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English (en)
French (fr)
Japanese (ja)
Inventor
弘明 高畑
清水　英満
公彦 矢可部
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住友化学株式会社
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Priority to KR20147024335A priority Critical patent/KR20150002598A/ko
Publication of WO2013146163A1 publication Critical patent/WO2013146163A1/ja

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J5/00—Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04—Interconnection of layers
    • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2255/00—Coating on the layer surface
    • B32B2255/10—Coating on the layer surface on synthetic resin layer or on natural or synthetic rubber layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2255/00—Coating on the layer surface
    • B32B2255/26—Polymeric coating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2457/00—Electrical equipment
    • B32B2457/20—Displays, e.g. liquid crystal displays, plasma displays
    • B32B2457/202—LCD, i.e. liquid crystal displays
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
    • C09J2203/318—Applications of adhesives in processes or use of adhesives in the form of films or foils for the production of liquid crystal displays
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/40—Additional features of adhesives in the form of films or foils characterized by the presence of essential components
    • C09J2301/416—Additional features of adhesives in the form of films or foils characterized by the presence of essential components use of irradiation
    • 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

Definitions

  • the present invention relates to a manufacturing method and a manufacturing apparatus of a polarizing plate used as a liquid crystal display member.
  • the liquid crystal panel that forms the core of a liquid crystal display device is usually configured by disposing polarizing plates on both sides of a liquid crystal cell.
  • a polarizing plate has a structure in which a protective film made of a transparent resin is bonded to one surface of a polarizing film made of a polyvinyl alcohol resin through an adhesive.
  • a transparent resin film is often bonded to the other surface of the polarizing film via an adhesive, and the transparent resin film on this side has only a protective function for the polarizing film, similar to the protective film on the opposite side.
  • the protective function it may be a so-called retardation film provided with an in-plane and / or thickness direction retardation for the purpose of optical compensation and viewing angle compensation of the liquid crystal cell.
  • optical film such a protective film or retardation film bonded to a polarizing film via an adhesive
  • the adhesive used for bonding the optical film to the polarizing film is generally a liquid, and exhibits an adhesive force between the polarizing film and the optical film by the curing reaction of the liquid adhesive.
  • the active energy ray curable adhesive is prepared in liquid form, and the die coater that directly applies the liquid adhesive to the object to be coated, or the liquid adhesive that is supported on the groove formed on the surface, is applied to the surface of the object to be coated.
  • the die coater that directly applies the liquid adhesive to the object to be coated, or the liquid adhesive that is supported on the groove formed on the surface, is applied to the surface of the object to be coated.
  • the optical film is preliminarily applied to the bonding surface to the polarizing film.
  • the polarizing film is piled up on the adhesive coating surface, active energy rays, such as an ultraviolet-ray and an electron beam, are irradiated, an adhesive agent is hardened, and adhesive force is expressed.
  • the method using such an active energy ray-curable adhesive is a very effective method because there are many applicable optical films.
  • a protective film is laminated on both surfaces of a polarizing film via an adhesive.
  • a method is disclosed in which a laminate is obtained, and active energy rays are irradiated while the laminate is brought into close contact with the outer surface of a convex curved surface formed in an arc shape along the conveying direction of the laminate. According to this method, the reverse curl and wave curl that are likely to occur in the obtained polarizing plate can be suppressed, and a polarizing plate having good performance can be produced.
  • ultraviolet rays When ultraviolet rays are used as active energy rays, it is common to use ultraviolet rays having a high energy and a short wavelength region of 400 nm or less.
  • the adhesive to be used an adhesive that reacts in this wavelength region and causes a curing reaction is generally used.
  • this ultraviolet curable adhesive it is possible to produce a polarizing plate with good adhesion between the polarizing film and the optical film, but in order to cure with ultraviolet rays in the above wavelength range, It can be considered that the film is cured by illumination such as a mercury lamp or a fluorescent lamp included in the polarizing plate manufacturing apparatus installed in the factory or in the facility.
  • the UV curable adhesive before use (coating) is prepared for the adhesive coating means of the polarizing plate manufacturing apparatus.
  • an ultraviolet curable adhesive before use if an unintended curing reaction is caused by the ultraviolet irradiation from the illumination, the adhesive performance may be deteriorated.
  • the polarizing film and the optical film are overlapped with the end face of the polarizing film or optical film coated with the ultraviolet curable adhesive or the coated ultraviolet curable adhesive.
  • An uncured ultraviolet curable adhesive may protrude from the end face of the laminate to be adhered to a guide roll or the like that transports the film.
  • the UV curable adhesive attached to the guide roll, etc. when an unintended curing reaction occurs due to the UV irradiation from the illumination, the UV curable adhesive attached to the guide roll etc. is removed and manufactured. It takes a lot of time to restore the process, and the operating rate of the manufacturing process is significantly reduced.
  • An object of the present invention is to prevent unintentional curing of an ultraviolet curable adhesive in the production of a polarizing plate in which an optical film is bonded to a polarizing film via an ultraviolet curable adhesive.
  • An object of the present invention is to provide a method for efficiently producing a polarizing plate having good adhesiveness without significantly reducing the operating rate of the production process.
  • the other object of this invention is to provide the polarizing plate manufacturing apparatus which can implement suitably the manufacturing method of the above polarizing plates.
  • the present inventors have a specific emission wavelength as illumination of a polarizing plate manufacturing facility (factory) or a polarizing plate manufacturing apparatus installed in the facility.
  • LED illumination By using LED illumination, the curing reaction of the ultraviolet curable adhesive used when laminating the polarizing film and the optical film is performed only in the ultraviolet irradiation process using the ultraviolet irradiation means, and other than this process.
  • the present inventors have found that an unintended curing reaction can be suppressed and have completed the present invention.
  • the present invention includes the following.
  • a method of manufacturing a polarizing plate by laminating an optical film made of a thermoplastic resin to a polarizing film made of a polyvinyl alcohol resin through an ultraviolet curable adhesive (A) a coating step of applying the ultraviolet curable adhesive to at least one bonding surface of the polarizing film and the optical film; (B) A laminating step of obtaining a laminate by superimposing the polarizing film and the optical film through the coated ultraviolet curable adhesive, and (C) irradiating the laminate with ultraviolet rays, Including an ultraviolet irradiation step of curing the ultraviolet curable adhesive; LED in which the coating step (A), the bonding step (B), and the ultraviolet irradiation step (C) have a light emission wavelength in a wavelength region exceeding 400 nm and no light emission wavelength in a wavelength region of 250 to 400 nm A method for producing a polarizing plate carried out under illumination.
  • the coating step is performed.
  • An apparatus for producing a polarizing plate by laminating an optical film made of a thermoplastic resin to a polarizing film made of a polyvinyl alcohol resin through an ultraviolet curable adhesive (A1) Coating means for applying the ultraviolet curable adhesive to at least one bonding surface of the polarizing film and the optical film, (B1) A bonding means for obtaining a laminate by superimposing the polarizing film and the optical film via the coated ultraviolet curable adhesive, (C1) Ultraviolet irradiation means for irradiating the laminate with ultraviolet rays to cure the ultraviolet curable adhesive, and (D1) The coating means (A1), the bonding means (B1), and the ultraviolet irradiation.
  • An apparatus for producing a polarizing plate comprising: LED illumination for illuminating the means (C1), having an emission wavelength in a wavelength range exceeding 400 nm and no emission wavelength in a wavelength range of 250 to 400 nm.
  • the curing reaction of the ultraviolet curable adhesive used when laminating the polarizing film and the optical film can be performed only in the ultraviolet irradiation process using the ultraviolet irradiation means,
  • the unintended curing reaction of the previous ultraviolet curable adhesive and the unintended curing reaction of the uncured ultraviolet curable adhesive attached to the guide roll or the like can be effectively suppressed. Therefore, a polarizing plate having good adhesion between the polarizing film and the optical film can be efficiently produced without significantly reducing the operating rate of the production process.
  • the coating state of the adhesive on the film during the polarizing plate manufacturing process can be clearly confirmed visually, which is advantageous for visually detecting defects in the coating state of the adhesive. is there.
  • FIG. 1 It is a schematic side view which shows an example of the polarizing plate manufacturing apparatus of this invention. It is an illumination intensity spectrum of LED illumination used in Example 1.
  • FIG. It is an illuminance spectrum of the ultraviolet cut fluorescent lamp used in Comparative Example 1. It is an illumination intensity spectrum of the fluorescent lamp used in Comparative Example 2.
  • an optical film made of a thermoplastic resin is bonded to a polarizing film made of a polyvinyl alcohol resin through an ultraviolet curable adhesive to produce a polarizing plate.
  • the optical film may be bonded only to one side of the polarizing film, or may be bonded to both sides of the polarizing film.
  • the polarizing film is made of polyvinyl alcohol-based resin, and is a film having a property of transmitting light having a vibration surface in a certain direction among light incident on the film and absorbing light having a vibration surface perpendicular thereto. Typically, it is a film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol resin.
  • the polyvinyl alcohol resin constituting the polarizing film can be obtained by saponifying a polyvinyl acetate resin.
  • the polyvinyl acetate resin used as a raw material for the polyvinyl alcohol resin is not only polyvinyl acetate, which is a homopolymer of vinyl acetate, but also a copolymer of vinyl acetate and other monomers copolymerizable therewith. May be.
  • a polarizing film is obtained by subjecting a film made of polyvinyl alcohol resin to uniaxial stretching treatment, dyeing treatment with a dichroic dye, and boric acid crosslinking treatment after dyeing.
  • a dichroic dye iodine or a dichroic organic dye is used.
  • Uniaxial stretching may be performed before dyeing with a dichroic dye, may be performed simultaneously with dyeing with a dichroic dye, or after dyeing with a dichroic dye, for example, during a boric acid crosslinking treatment. May be.
  • a polarizing film made of a polyvinyl alcohol-based resin thus manufactured and having a dichroic dye adsorbed and oriented is one of the raw materials for the polarizing plate.
  • optical film An optical film made of a thermoplastic resin is bonded to the polarizing film to produce a polarizing plate.
  • the optical film preferably has a refractive index measured by D-ray at a temperature of 20 ° C. in the range of 1.4 to 1.7.
  • the refractive index of the optical film is measured according to JIS K 0062: 1992 “Method for measuring refractive index of chemical product”. If the optical film has a refractive index in this range, it will have excellent display characteristics when the produced polarizing plate is incorporated in a liquid crystal panel. For the same reason, the preferred refractive index of the optical film is in the range of 1.45 to 1.67.
  • the optical film has a haze value in the range of about 0.001 to 10%, which improves the contrast of the obtained polarizing plate, particularly when it is incorporated into a liquid crystal panel to display black and has a problem such as a decrease in luminance. This is preferable because the possibility of occurrence of is reduced.
  • the haze value is a value defined by (diffuse transmittance / total light transmittance) ⁇ 100 (%), and is measured in accordance with JIS K 7136: 2000 “How to determine haze of plastic and transparent material”.
  • thermoplastic resin constituting the optical film examples include the following, and here, the refractive index measured by the D line at a temperature of 20 ° C. is also displayed as n D (20 ° C.).
  • the cycloolefin resin is a polymer having a cycloolefin monomer such as norbornene as a main structural unit, a resin obtained by hydrogenating a ring-opening polymer of a cycloolefin monomer, a cycloolefin monomer, Examples include addition polymers with chain olefin monomers having 2 to 10 carbon atoms such as ethylene and propylene and / or aromatic vinyl monomers such as styrene.
  • the crystalline polyolefin resin is a polymer mainly composed of a chain olefin monomer having 2 to 10 carbon atoms, which is a homopolymer of a chain olefin monomer and two or more types of chain olefin monomers. Binary or ternary or higher copolymers using are included. Specifically, a polyethylene resin, a polypropylene resin, an ethylene-propylene copolymer, a homopolymer of 4-methyl-1-pentene, a copolymer of 4-methyl-1-pentene and ethylene or propylene, etc. Is included.
  • Polyester resin includes aliphatic polyester as well as aromatic polyester such as polyethylene terephthalate resin and polyethylene naphthalate resin.
  • the polycarbonate resin is typically a polymer obtained by a reaction of bisphenol A and phosgene, and having a carbonate bond —O—CO—O— in the main chain.
  • the acrylic resin is typically a polymer mainly composed of methyl methacrylate. In addition to a methyl methacrylate homopolymer, methyl methacrylate and other methacrylate esters and / or acrylic esters. And copolymers thereof are also included.
  • Triacetyl cellulose resin is an acetate of cellulose. From these thermoplastic resins, a film can be formed into a film by a solvent casting method, a melt extrusion method, or the like to obtain an optical film used in the present invention. Moreover, what was extended
  • the optical film preferably has a thickness of usually about 5 to 200 ⁇ m. If the optical film is too thin, the handling property is lacking, and there is a high possibility that the optical film will be broken in the polarizing plate production line or cause wrinkles. On the other hand, if it is too thick, the resulting polarizing plate becomes thick and the weight increases, which may impair the commercial properties. For these reasons, a more preferable thickness of the optical film is 10 to 120 ⁇ m, and a more preferable thickness is 10 to 85 ⁇ m.
  • UV curable adhesive When bonding an optical film to a polarizing film, first, an ultraviolet curable adhesive is applied to at least one bonding surface of the polarizing film and the optical film. Typically, an ultraviolet curable adhesive is applied to the bonding surface of the optical film to the polarizing film.
  • the thickness of the ultraviolet curable adhesive is preferably in the range of 0.5 to 5 ⁇ m. If the thickness is less than 0.5 ⁇ m, uneven adhesion strength may occur. On the other hand, when the thickness exceeds 5 ⁇ m, not only the manufacturing cost increases, but also the hue of the polarizing plate may be affected depending on the kind of the adhesive.
  • the thickness is relatively large within the above range, for example, 3.5 ⁇ m or more, especially 4 ⁇ m or more, even if the thickness slightly varies, defects such as bubbles are less likely to appear. Since increasing the thickness may lead to an increase in cost, it is desirable to reduce the thickness as much as possible. For these reasons, the preferred thickness of the adhesive is in the range of 1 to 4 ⁇ m, more preferably 1.5 to 3.5 ⁇ m.
  • the UV curable adhesive is supplied in a liquid coatable state, it can be any of those conventionally used in the production of polarizing plates, but from the viewpoint of weather resistance, polymerizability, etc.
  • a cationically polymerizable compound such as an epoxy compound, more specifically, an epoxy compound having no aromatic ring in the molecule, as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-245925).
  • An adhesive contained as one of the ultraviolet curable components is preferred.
  • the epoxy compound is, for example, a hydrogenated epoxy compound obtained by nuclear hydrogenation of an aromatic polyhydroxy compound which is a raw material of an aromatic epoxy compound represented by diglycidyl ether of bisphenol A and glycidyl ether.
  • an alicyclic epoxy compound having at least one epoxy group bonded to the alicyclic ring in the molecule and an aliphatic epoxy compound typified by a glycidyl ether of an aliphatic polyhydroxy compound.
  • UV curable adhesives In addition to cationically polymerizable compounds, typically epoxy compounds, UV curable adhesives usually generate polymerization initiators, especially cationic species or Lewis acids upon irradiation with ultraviolet rays, and polymerize cationically polymerizable compounds.
  • a photocationic polymerization initiator for initiating the reaction is blended.
  • a thermal cationic polymerization initiator that initiates polymerization by heating, and various other additives such as a photosensitizer may be blended.
  • the ultraviolet curable adhesive applied to each optical film may be the same or different, but from the viewpoint of productivity, moderate adhesion It is preferable to use the same UV curable adhesive on both sides on the premise that strength can be obtained.
  • polarizing plate manufacturing method and polarizing plate manufacturing apparatus an optical film is bonded to the polarizing film which consists of a polyvinyl alcohol-type resin demonstrated above through an ultraviolet curable adhesive, and a polarizing plate is manufactured.
  • the manufacturing method of the polarizing plate of this invention contains the following (A), (B) and (C) in this order.
  • A a coating step of applying an ultraviolet curable adhesive to at least one bonding surface of the polarizing film and the optical film;
  • B A laminating step in which a polarizing film and an optical film are superposed through a coated ultraviolet curable adhesive to obtain a laminate, and
  • C an ultraviolet curable adhesive by irradiating the laminate with ultraviolet rays. UV irradiation process to cure.
  • the coating step (A), the bonding step (B), and the ultraviolet irradiation step (C) have an emission wavelength in a wavelength region exceeding 400 nm and do not have an emission wavelength in a wavelength region of 250 to 400 nm. Implemented under LED lighting.
  • the polarizing plate production apparatus of the present invention is an apparatus that can suitably carry out the polarizing plate production method according to the present invention, and includes the following (A1), (B1), (C1), and (D1).
  • FIG. 1 is a side view schematically showing an example of a polarizing plate production apparatus of the present invention.
  • the first optical film 2 is bonded to one surface while the polarizing film 1 is continuously conveyed, and the second optical film 3 is bonded to the other surface.
  • the polarizing plate 4 is manufactured by bonding, and is wound around the winding roll 30.
  • an optical film is bonded to both surfaces of the polarizing film 1, but a mode in which the optical film is bonded only to one surface of the polarizing film 1 is also included in the present invention.
  • the form in that case will be understood by a person skilled in the art to the extent that it can be easily implemented by excluding the description of the other optical film from the following description.
  • the coating step (A) one of the first optical film 2 and the second optical film 3 fed out from the roll bodies 31 and 32.
  • the surface is coated with an ultraviolet curable adhesive from the gravure rolls 11 and 13 of the first coating machine 10 and the second coating machine 12 which are the coating means (A1).
  • a conveying guide roll 24 is appropriately provided on one surface of the polarizing film 1 and the surface of the first optical film 2 and the second optical film 3 opposite to the surface to which the ultraviolet curable adhesive is applied.
  • a conveying guide roll 24 is appropriately provided on one surface of the polarizing film 1 and the surface of the first optical film 2 and the second optical film 3 opposite to the surface to which the ultraviolet curable adhesive is applied.
  • the first optical film 2 and the second optical film 3 to which the ultraviolet curable adhesive has been applied are overlapped on both surfaces of the polarizing film 1, respectively.
  • the laminate is obtained by being pressed between the nip rolls 20 and 21 for bonding, which is a bonding means (B1), in the thickness direction.
  • the laminate is irradiated with ultraviolet rays using the ultraviolet irradiation device 14 which is the ultraviolet irradiation means (C1), and the ultraviolet curable adhesive is cured.
  • the obtained polarizing plate 4 is wound around the winding roll 30 via the nip rolls 22 and 23 before winding.
  • the optical film when the optical film is bonded only to one surface of the polarizing film 1, only one of the first optical film 2 and the second optical film 3 shown in FIG. Only one optical film 2) may be applied.
  • the straight arrows in the figure indicate the film flow direction, and the curved arrows indicate the roll rotation direction.
  • Coating process (A) In the coating step (A), an ultraviolet curable adhesive is applied to the bonding surfaces of the first and second optical films 2 and 3 to the polarizing film 1.
  • the coating machine as the coating means (A1) used here preferably has a means for controlling the coating thickness, and as such a gravure roll 11 described with reference to FIG. , 13 is typical.
  • the gravure rolls 11 and 13 are rolls having concave grooves, and the concave grooves are filled with an ultraviolet curable adhesive in advance, and the first and second optical films 2 and 3 are rotated in this state.
  • the ultraviolet curable adhesive is transferred onto the first and second optical films 2 and 3.
  • Examples of the coating machine using the gravure rolls 11 and 13 include a direct gravure coater, a chamber doctor coater, an offset gravure coater, a kiss coater using a gravure roll, and a reverse roll coater composed of a plurality of rolls.
  • a comma coater that has a cylindrical blade, supplies the coating part with an adhesive, and scrapes it off with the blade, and applies a slot die to directly apply the adhesive.
  • Various coating machines such as a knife coater that creates a reservoir and scrapes off excess liquid with a knife, can be used.
  • direct gravure coater, chamber doctor coater, offset gravure coater, etc. are preferable among coating machines using gravure rolls, considering thin film coating and pass line freedom, etc.
  • a die coater using a slot die is also preferable.
  • a chamber doctor coater is more preferable because it can easily cope with the widening of the polarizing plate and hardly releases the odor of the ultraviolet curable adhesive supplied as a liquid.
  • the chamber doctor coater makes the gravure roll contact the chamber doctor that has absorbed the liquid paint (adhesive), and transfers the paint (adhesive) in the chamber doctor to the concave groove of the gravure roll.
  • a coating machine that transfers the film to the first and second optical films 2 and 3.
  • the compact design is also called a microchamber doctor coater.
  • the thickness of the adhesive layer can be adjusted by the speed ratio of the gravure roll to the line speed.
  • the line speed of the first and second optical films 2 and 3 is set to 10 to 50 m / min, and the gravure roll is rotated in the opposite direction with respect to the conveying direction of the first and second optical films 2 and 3.
  • the thickness of the adhesive layer can be adjusted to 0.5 to 5 ⁇ m, for example. Since the thickness of the adhesive layer is also affected by the porosity of the gravure roll surface, it is preferable to select a gravure roll having a surface porosity suitable for the set thickness in advance.
  • the system which rotates a gravure roll reversely with respect to the conveyance direction of the 1st, 2nd optical films 2 and 3 is also called a reverse gravure.
  • the thickness of the adhesive layer applied to the bonding surface of the first and second optical films 2 and 3 with the polarizing film 1 is measured, and the adhesive layer It is preferable to control the thickness of the film so as to be constant.
  • a measurement method an arbitrary method such as a light interference method, a laser light interference method, an ultrasonic method, a method using radiation such as ⁇ rays or X rays can be adopted.
  • the thickness of the first and second optical films 2 and 3 is measured, the total thickness of the adhesive and the optical film after coating is measured, and the adhesive layer is determined from the absolute value of the difference between these measured values.
  • the method of obtaining the thickness of the film is preferable from the viewpoint of high measurement accuracy and measurement stability.
  • the polarizing film 1 is directly applied to a polyvinyl alcohol resin film in a state of being manufactured through a uniaxial stretching process, a dyeing process with a dichroic dye, and a boric acid crosslinking process after dyeing in a polarizing film manufacturing process (not shown). Often, it is provided to the step (A), but of course, the polarizing film manufactured in the polarizing film manufacturing step may be once wound around a roll and then fed out again by a feeding machine. On the other hand, the first optical film 2 and the second optical film 3 are fed out from the roll bodies 31 and 32 by a feeding machine, respectively.
  • Each film is conveyed so as to have the same flow direction at the same line speed, for example, a line speed of about 10 to 50 m / min.
  • the first optical film 2 and the second optical film 3 are fed out while applying a tension of about 50 to 1000 N / m in the flow direction.
  • Pasting process (B) After passing through the coating step (A), there is a bonding step (B) in which the polarizing film 1 is stacked and pressed on each adhesive coating surface of the first and second optical films 2 and 3 to obtain a laminate. Done.
  • a well-known means can be used for the bonding means (B1) in this process, as shown in FIG. 1, a pair of bonding is possible from a viewpoint that pressurization and bonding are possible while continuously conveying.
  • a method of sandwiching between the nip rolls 20 and 21 is preferable. In this case, it is desirable that the timing of superimposing the first and second optical films 2 and 3 on the polarizing film 1 and the timing of applying pressure by the pair of nip rolls 20 and 21 are the same.
  • the combination of the pair of nip rolls 20 and 21 may be any of metal roll / metal roll, metal roll / rubber roll, rubber roll / rubber roll, and the like.
  • the pressure during pressurization is preferably about 150 to 500 N / cm as the linear pressure when sandwiched between the pair of nip rolls 20 and 21.
  • UV irradiation process As described above, after the first and second optical films 2 and 3 are bonded to the polarizing film 1 to obtain a laminate, an adhesive layer made of an ultraviolet curable adhesive is cured by irradiation with ultraviolet rays.
  • the polarizing plate 4 is manufactured through the ultraviolet irradiation step (C).
  • This ultraviolet irradiation step (C) is performed by irradiating the laminate with ultraviolet rays from the ultraviolet irradiation device 14 as the ultraviolet irradiation means (C1). In this step, ultraviolet light having energy necessary for curing the ultraviolet curable adhesive is irradiated through the first optical film 2 (or the second optical film 3).
  • irradiation of the laminate with ultraviolet rays applied tension to the laminate between the nip rolls 20 and 21 for bonding before and after the ultraviolet irradiation device 14 and the nip rolls 22 and 23 before winding. It is to be performed in the state.
  • the present invention is not limited to this, for example, a convex curved surface formed in an arc shape along the conveying direction as disclosed in the above-mentioned Patent Document 2 (Japanese Patent Laid-Open No. 2009-134190), typically the outer peripheral surface of the roll. It is also preferable to irradiate with ultraviolet rays while being supported by the substrate.
  • the roll supporting the laminated body can be adjusted in temperature in the range of about 10 to 60 ° C.
  • the ultraviolet irradiation device 14 may be provided at the irradiation site, two or more ultraviolet irradiation devices along the flow direction of the laminated body and irradiation from a plurality of light sources are effective in effectively increasing the integrated light quantity. is there. In any case, it is preferable that the ultraviolet irradiation device 14 is configured to irradiate ultraviolet rays only to the laminate that passes immediately below.
  • the ultraviolet light source of the ultraviolet irradiation device 14 is not particularly limited, it has a light emission distribution at a wavelength of 400 nm or less.
  • a metal halide lamp or the like can be used.
  • a high pressure mercury lamp or a metal halide lamp having a large amount of light of 400 nm or less is preferably used as the ultraviolet light source in consideration of an absorption wavelength exhibited by a general polymerization initiator.
  • the irradiation amount in the wavelength region effective for activating the polymerization initiator is the integrated light amount (total energy irradiated to the laminate). It is preferable to irradiate with ultraviolet rays so as to be 100 to 1500 mJ / cm 2 . If the accumulated light amount is too small, the curing reaction of the UV curable adhesive will be insufficient, and sufficient adhesive strength will not be expressed. On the other hand, if the accumulated light amount is too large, the heat and adhesive emitted from the light source will be polymerized. The heat generated during the process may cause yellowing of the ultraviolet curable adhesive and deterioration of the polarizing film.
  • the film may be heated to a high temperature exceeding 150 ° C. due to heat generation. In this case, the polarizing film may be deteriorated.
  • it is effective to provide a plurality of ultraviolet irradiation devices along the film conveyance direction and to irradiate a plurality of times.
  • it may be preferable to set the irradiation amount from one ultraviolet irradiation device to 600 mJ / cm 2 or less in terms of the integrated light amount so that the above-mentioned integrated light amount of 100 to 1500 mJ / cm 2 is finally obtained. is there.
  • the illuminance meter 15 is preferably one that can measure the illuminance for each wavelength by dispersing the irradiated ultraviolet rays for each wavelength. It is possible to continuously produce a polarizing plate having sufficient adhesive strength by integrating the illuminance in the wavelength region necessary for the curing reaction, obtaining the integrated light amount, and managing the irradiation amount from the ultraviolet irradiation device 14 based on this. it can.
  • the line speed of the laminate in the ultraviolet irradiation step (C) is not particularly limited, but generally the line speed in the coating step (A) and the bonding step (B) is maintained almost as it is.
  • the coating step (A), the bonding step (B) and the ultraviolet irradiation step (C) have an emission wavelength in a wavelength region exceeding 400 nm, and a wavelength region of 250 to 400 nm. This is performed under LED (light emitting diode) illumination (D1) having no emission wavelength.
  • the LED illumination (D1) illuminates at least the coating means (A1), the bonding means (B1), and the ultraviolet irradiation means (C1).
  • An LED illumination (D1) having a light emission wavelength in a wavelength region exceeding 400 nm and not having a light emission wavelength in a wavelength region of 250 to 400 nm is a power monitor having a spectral function (for example, spectral radiation manufactured by Otsuka Electronics Co., Ltd.)
  • a spectral function for example, spectral radiation manufactured by Otsuka Electronics Co., Ltd.
  • an illuminance peak is observed in a wavelength region exceeding 400 nm, and 250 It is LED illumination in which the peak of illuminance is not seen in the wavelength range of ⁇ 400 nm.
  • LED lighting emits light when a voltage is applied to a PN junction composed of a P-type semiconductor and an N-type semiconductor called an LED chip, but the emission color is blue depending on the type of compound constituting the LED chip. (Around 450 nm), green (around 520 nm) or red (around 660 nm).
  • White LED lighting is a combination of blue light emission and yellow phosphor, which excites the phosphor from blue light emission to produce white light emission; a combination of blue light emission and red / green phosphor excites the phosphor.
  • White light emission by mixing blue, green and red light emission, and these LED illuminations have a light emission wavelength in the wavelength region exceeding 400 nm and have a wavelength of 250 to 400 nm.
  • LED lighting Since it does not have an emission wavelength in the wavelength range, it can be used as LED lighting (D1). In the combination of the LED chip and the phosphor, LED lighting whose LED chip emission wavelength is near 360 nm in the ultraviolet region or 405 nm is also being developed, but these have an emission wavelength of 400 nm or less. Therefore, it is not suitable for LED lighting (D1).
  • UV curing adhesive and optical film (or polarizing film) coated with UV curing adhesive can prevent the unintended curing reaction from progressing, and bonding process (B) and UV irradiation process (C) In this case, it is possible to suppress the unintended (not based on the ultraviolet irradiation device) curing reaction of the ultraviolet curable adhesive protruding from the end of the laminate. Thereby, the fall of the adhesive performance of the ultraviolet curable adhesive by a hardening reaction advancing before coating can be suppressed.
  • the UV curable adhesive that protrudes from the edge of the laminate adheres to the guide roll or the like, or the film such as an optical film breaks during the manufacturing process, and the applied UV curable adhesive scatters. Even when a manufacturing trouble such as this occurs, the adhesive attached to the guide roll or the like can be prevented from being cured, so that these adhesives can be easily removed with a solvent or the like. Thereby, even when the above manufacturing trouble occurs, the manufacturing process can be restored in a short time, and the polarizing plate can be manufactured without significantly reducing the operating rate of the manufacturing process. The obtained polarizing plate protrudes from the edge part of a laminated body, and there is little frequency which produces defects, such as a dent resulting from the hardened
  • the curing reaction of the ultraviolet curable adhesive proceeds only with the ultraviolet rays irradiated in the ultraviolet irradiation step (C)
  • the cumulative amount of ultraviolet rays from the ultraviolet irradiation device is used to irradiate the ultraviolet rays with the set cumulative amount of light.
  • the coating state of the adhesive on the film during the polarizing plate manufacturing process can be clearly confirmed by visual observation. It is also advantageous for detection.
  • an ultraviolet cut fluorescent lamp in which an ultraviolet cut filter is installed in a general fluorescent lamp, an illuminance peak of 400 nm or less can be cut. It is very difficult to visually confirm the coating state of the adhesive on the film during the process.
  • the installation position of the LED illumination (D1) is not particularly limited as long as it can illuminate all of the coating means (A1), the bonding means (B1), and the ultraviolet irradiation means (C1), and the polarizing plate manufacturing apparatus is installed.
  • the polarizing plate manufacturing facility may be installed above (for example, the ceiling), or the polarizing plate manufacturing apparatus itself may be equipped with the LED illumination (D1), or both. Good.
  • the polarizing plate manufacturing apparatus of the present invention itself includes LED illumination (D1).
  • the polarizing plate manufacturing apparatus accommodates the coating means (A1), the bonding means (B1), and the ultraviolet irradiation means (C1) (coating process ( A), one or more chambers (covering the periphery of the manufacturing process part in which the bonding step (B) and the ultraviolet irradiation step (C) are performed) can be provided, and one or more LED illuminations (D1) in this chamber Can be installed.
  • a total of four chambers each accommodating two coating means (A1), one bonding means (B1), and one ultraviolet irradiation means (C1) are provided.
  • One LED illumination (D1) (LED illumination 40, 41, 42, 43) is provided in each of the two chambers. From the viewpoint of effective use of the work space, it is preferable that the LED illumination (D1) be installed above (for example, the ceiling) or laterally (side of the chamber) in the chamber.
  • a coating means (A1), a bonding means (B1), and an ultraviolet irradiation means (C1) are accommodated in the polarizing plate manufacturing apparatus (the coating process (A), the bonding process (B), and the ultraviolet irradiation process (C)
  • the coating process (A), the bonding process (B), and the ultraviolet irradiation process (C) In the case where a chamber is provided that covers the periphery of the manufacturing process portion where the manufacturing process is performed) and the LED illumination (D1) is installed in the chamber, the illumination of the polarizing plate manufacturing facility (factory) is not necessarily LED. There is no need for illumination (D1).
  • an uncured ultraviolet curable adhesive may be brought into the subsequent process of the ultraviolet irradiation process (C). Therefore, the steps from the ultraviolet irradiation step (C) to the winding of the polarizing plate 4 by the winding roll 30 are also performed under the LED illumination (D1) so that the adhesive can be easily removed even in such a case. It is preferable to do.
  • the polarizing plate manufacturing apparatus for manufacturing the polarizing plate has the configuration shown in FIG. 1 and is used for bonding the polarizing film 1 and the first optical film 2.
  • an adhesive and an adhesive used for adhesion between the polarizing film 1 and the second optical film 3 an epoxy-based ultraviolet curable adhesive that contains an epoxy compound and a photopolymerization initiator and substantially does not contain a solvent.
  • the first optical film 2 a biaxially oriented cycloolefin resin film [obtained from Nippon Zeon Co., Ltd.] having a thickness of 60 ⁇ m and a width of 1330 mm is used as the second optical film 3.
  • a second coating machine 12 (“Microchamber Doctor” manufactured by Fuji Machine Co., Ltd.) provided with a gravure roll 12 is used.
  • the UV curable adhesive was applied so that the thickness of the adhesive layer was 3.5 ⁇ m [Coating process (A)].
  • the respective adhesive-coated surfaces of the first optical film 2 and the second optical film 3 coated with the ultraviolet curable adhesive are superposed on the polarizing film 1, and 240 N / O is applied by the nip rolls 20 and 21 for bonding. Clamped with a linear pressure of cm [bonding step (B)].
  • the laminated body after passing through the nip rolls 20 and 21 is irradiated with ultraviolet rays from the ultraviolet irradiation device 14 to cure the ultraviolet curing type [ultraviolet irradiation step (C)], and the obtained polarizing plate 4 is wound. It was wound up on a take-up roll 30.
  • the ultraviolet irradiation device 14 two ultraviolet lamps “EHAN1700NAL high-pressure mercury lamp” manufactured by GS Yuasa Co., Ltd. were used. The cumulative amount of ultraviolet light was 330 mJ / cm 2 for the two lamps.
  • the ceiling of the four chambers covering the periphery of the manufacturing process part where the coating process (A), the bonding process (B), and the ultraviolet irradiation process (C) are performed has emission wavelengths in a wavelength region exceeding 400 nm respectively.
  • LED lighting 40, 41, 42, 43 having no emission wavelength in the wavelength region of 250 to 400 nm is installed, and the coating process (A), the bonding process (B), and the ultraviolet irradiation process (C) are these It was carried out under LED lighting.
  • the illuminance spectrum of the LED lighting 40, 41, 42, 43 used is shown in FIG.
  • the illuminance spectrum of LED illumination is obtained by using a spectral irradiance measurement system “MCPD-3700” (detector 2480C) manufactured by Otsuka Electronics Co., Ltd. Measured in the wavelength range. Measurement conditions were such that the measured values were accumulated eight times with a light capture time of 400 milliseconds. Illuminance (W / min / nm) at each wavelength for every 1 nm was obtained. It was confirmed that the LED illumination used in this example does not have an emission wavelength in the wavelength range of 250 to 400 nm.
  • Example 1 A polarizing plate was produced in the same manner as in Example 1 except that instead of the LED illumination in Example 1, an ultraviolet cut fluorescent lamp having no emission wavelength in the wavelength range of 250 to 400 nm was used. The illuminance spectrum of the ultraviolet cut fluorescent lamp used is shown in FIG.
  • Example 2 A polarizing plate was produced in the same manner as in Example 1 except that a fluorescent lamp having an emission wavelength in the vicinity of 365 nm was used instead of the LED illumination in Example 1. The illuminance spectrum of the fluorescent lamp used is shown in FIG.
  • Example 1 and Comparative Example 2 the coating state of the adhesive layer end could be easily visually observed, but in Comparative Example 1, it was not visually observed.
  • Example 1 In Example 1 and Comparative Example 1, there was no adhesive solidifying component, and the adhesive could be easily removed. On the other hand, in Comparative Example 2, the shape of the adhesive droplet remained even after wiping, and this could not be removed.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Polarising Elements (AREA)
  • Laminated Bodies (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Liquid Crystal (AREA)
PCT/JP2013/056269 2012-03-29 2013-03-07 偏光板の製造方法および製造装置 WO2013146163A1 (ja)

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JP6823919B2 (ja) * 2015-09-08 2021-02-03 日東電工株式会社 光学フィルムおよびその製造方法
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WO1997012841A1 (fr) * 1995-10-06 1997-04-10 Sumitomo Electric Industries, Ltd. Procede et equipement permettant de recouvrir une fibre optique
JP2004245925A (ja) * 2003-02-12 2004-09-02 Sumitomo Chem Co Ltd 偏光板、その製造法、光学部材及び液晶表示装置
JP2009134190A (ja) * 2007-11-30 2009-06-18 Sumitomo Chemical Co Ltd 偏光板の製造方法
JP2010033743A (ja) * 2008-07-25 2010-02-12 Gc Corp 歯科用照明装置
JP2012063321A (ja) * 2010-09-17 2012-03-29 Hamamatsu Photonics Kk 反射率測定装置、反射率測定方法、膜厚測定装置及び膜厚測定方法

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JP5693108B2 (ja) * 2010-03-30 2015-04-01 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． 蛍光体、その製造方法及びこれを有する発光装置
JP2011222381A (ja) * 2010-04-13 2011-11-04 Skynet Electronics Co Ltd Ｌｅｄライトの放熱ハウジング

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WO1997012841A1 (fr) * 1995-10-06 1997-04-10 Sumitomo Electric Industries, Ltd. Procede et equipement permettant de recouvrir une fibre optique
JP2004245925A (ja) * 2003-02-12 2004-09-02 Sumitomo Chem Co Ltd 偏光板、その製造法、光学部材及び液晶表示装置
JP2009134190A (ja) * 2007-11-30 2009-06-18 Sumitomo Chemical Co Ltd 偏光板の製造方法
JP2010033743A (ja) * 2008-07-25 2010-02-12 Gc Corp 歯科用照明装置
JP2012063321A (ja) * 2010-09-17 2012-03-29 Hamamatsu Photonics Kk 反射率測定装置、反射率測定方法、膜厚測定装置及び膜厚測定方法

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