WO2014204132A1 - Thin polarizer with excellent optical properties, method for manufacturing same, and polarizing plate and display device comprising thin polarizer - Google Patents

Thin polarizer with excellent optical properties, method for manufacturing same, and polarizing plate and display device comprising thin polarizer Download PDF

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Publication number
WO2014204132A1
WO2014204132A1 PCT/KR2014/005184 KR2014005184W WO2014204132A1 WO 2014204132 A1 WO2014204132 A1 WO 2014204132A1 KR 2014005184 W KR2014005184 W KR 2014005184W WO 2014204132 A1 WO2014204132 A1 WO 2014204132A1
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Prior art keywords
film
polyvinyl alcohol
thin polarizer
stretching
polarizer
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PCT/KR2014/005184
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French (fr)
Korean (ko)
Inventor
남성현
정종현
나균일
유혜민
Original Assignee
주식회사 엘지화학
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Priority claimed from KR1020140067776A external-priority patent/KR20140147009A/en
Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to US14/386,296 priority Critical patent/US9684104B2/en
Priority to CN201480000908.0A priority patent/CN104395790B/en
Priority to JP2016518280A priority patent/JP6302053B2/en
Publication of WO2014204132A1 publication Critical patent/WO2014204132A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • 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
    • G02B5/3041—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 comprising multiple thin layers, e.g. multilayer stacks
    • G02B5/305—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 comprising multiple thin layers, e.g. multilayer stacks including organic materials, e.g. polymeric layers
    • 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
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2329/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal, or ketal radical; Hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Derivatives of such polymer
    • C08J2329/02—Homopolymers or copolymers of unsaturated alcohols
    • C08J2329/04—Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids

Definitions

  • the present invention relates to a thin polarizer, a method for manufacturing the same, a polarizing plate and a display device including the same, more specifically, a thin polarizer having excellent optical properties and having a thickness of 10 ⁇ m or less, a manufacturing method thereof, and a polarizing plate including the same. And a display device.
  • the polarizer used in the polarizing plate is an optical element for making natural light or arbitrary polarization into a polarized light in a specific direction, and is widely used in a display device such as a liquid crystal display device and an organic light emitting device (OLED).
  • a polarizer used in the display device a polyvinyl alcohol polarizing film in which molecular chains containing an iodine compound or a dichroic dye are oriented in a constant direction is generally used.
  • the polyvinyl alcohol polarizing film is prepared by a method of dyeing and crosslinking iodine or dichroic dye on a polyvinyl alcohol-based film, and stretching in a predetermined direction, wherein the stretching process is an aqueous solution of boric acid or an iodine solution. It may be performed by wet stretching performed in solution or dry stretching performed in air.
  • stretching exceeds 60 micrometers.
  • polarizers are also required to have a thinner thickness.
  • a polyvinyl alcohol-based film having a thickness before stretching of more than 60 ⁇ m as in the prior art there is a limit in reducing the thickness of the polarizer. Therefore, studies have been attempted to fabricate thinner polarizers.
  • Korean Unexamined Patent Publication No. 2010-0071998 discloses a method of manufacturing a thin polarizing plate using a laminate prepared by coating a hydrophilic polymer layer on a substrate layer or co-extrusion of a substrate layer forming material and a hydrophilic polymer layer forming material. It is.
  • the separation of the polyvinyl alcohol layer and the base layer is not easy after stretching and a high peel force is required for the separation, the polyvinyl alcohol layer is damaged or deformed during the separation process. Problems tend to occur, and as a result, there is a problem that optical properties such as polarization degree of the polyvinyl alcohol film are inferior.
  • the polyvinyl alcohol resin is manufactured by melting and extruding the polyvinyl alcohol resin or by applying the coating solution after coating and then applying the polyvinyl alcohol according to extrusion conditions, coating conditions or film forming conditions.
  • the physical properties of the film tend to change, and not only the physical properties of the finally produced polyvinyl alcohol are lowered, but also it is difficult to realize uniform physical properties.
  • the present invention is to solve the problems as described above, the polyalcohol-based thin polarizer having a single optical transmittance of 40 ⁇ 45%, a polarization degree of 99.0% or more, excellent in optical properties, and a thickness of 10 ⁇ m or less and its manufacturing method To provide.
  • the present invention comprises the steps of attaching a non-stretched polyvinyl alcohol-based film to the at least one surface of the thermoplastic polyurethane film by using an attractive force or an adhesive to form a film laminate; Stretching the film laminate at a temperature of 45 ° C. to 55 ° C .; And it provides a method for producing a thin polarizer comprising the step of separating the polyurethane film and the polyvinyl alcohol-based film.
  • the unstretched polyvinyl alcohol film is preferably 10 ⁇ m to 60 ⁇ m thickness
  • the stretching step is carried out in boric acid solution of boric acid concentration of 1 to 5%, preferably 1 to 3%. Can be.
  • the separating of the polyurethane film and the polyvinyl alcohol-based film may be performed by applying a peel force of 2N / 2cm or less.
  • the manufacturing method of the thin polarizer of the present invention further comprises the step of dyeing at least one of iodine and dichroic dye on the film laminate before the stretching step, or drying the film laminate after the stretching step It may further comprise a step.
  • the present invention has a polarization degree measured at ten points having a thickness of 10 ⁇ m or less, a single transmittance of 40% to 45%, a degree of polarization of 99.0% or more, and positioned at equal intervals along the width direction of the polarizer.
  • a thin polarizer having a standard deviation of 0.002% or less, a polarizing plate and a display device including the same.
  • the thin polarizer manufactured by the manufacturing method of this invention is not only very thin but 10 micrometers in thickness, and is excellent also in optical properties, such as a single transmittance, polarization degree, and color.
  • 1 is a schematic diagram showing a method for measuring adhesion using a texture analyzer (Texture Analyzer).
  • FIG. 2 is a photograph showing a film laminate in which breakage occurred in the stretching step of Comparative Example 4.
  • the present inventors have conducted a long study to manufacture a polarizer having no optical breakage and excellent in optical properties even though the fracture does not occur in the manufacturing process, and as a result, a weak attraction or adhesive of a polyvinyl alcohol-based film on a polymer film It was found that the above object can be achieved by attaching the same, and stretching the same.
  • Korean Patent Application No. 10-2012-0130576 and Korean Patent Application No. 10-2012-0130577 I've done it.
  • the present inventors conducted further studies in the above-described method for producing a thin polarizer, by using a thermoplastic polyurethane film as a polymer film and performing stretching at a specific temperature, compared to the case of using other types of films It was found out that a thin polarizer having very excellent optical properties could be produced and completed the present invention.
  • a method of manufacturing a thin polarizer includes: attaching an unstretched polyvinyl alcohol-based film to at least one surface of a thermoplastic polyurethane film by using attraction force or an adhesive to form a film laminate; Stretching the film laminate at a temperature of 45 ° C. to 55 ° C .; And separating the polyurethane film and the polyvinyl alcohol-based film.
  • thermoplastic polyurethane film is to prevent the polyvinyl alcohol-based film from breaking, according to the research of the present inventors, when using a polyurethane film as a base film, compared with the case of using a film of a different material Stretching is possible, and since the heat shrinkage property is similar to the polyvinyl alcohol-based film, it can induce smooth width shrinkage without inhibiting the width shrinkage of the stretched polyvinyl alcohol film in the drying process, and thus has excellent optical properties. It has been shown that polarizers can be produced.
  • the polyurethane film usable in the present invention may be a thermoplastic polyurethane film having a maximum draw ratio of 5 times or more, preferably 8 times or more at a temperature of 45 ° C to 55 ° C, and is not particularly limited.
  • the polyurethane film has a thickness of about 20 to 100 ⁇ m, preferably 30 to 80 ⁇ m. This is because if the thickness of the polyurethane film is less than 20 ⁇ m, the breakage probability is high, and if it exceeds 100 ⁇ m, the stretching efficiency after the film laminate is formed may decrease.
  • the polyvinyl alcohol-based film attached to the thermoplastic polyurethane film has a thickness of about 10 ⁇ m to 60 ⁇ m, preferably 10 ⁇ m to 40 ⁇ m.
  • the thickness of the polyvinyl alcohol-based film exceeds 60 ⁇ m, it is difficult to achieve a thickness of less than 10 ⁇ m even when stretched, when the thickness is less than 10 ⁇ m tends to break during stretching.
  • the polyvinyl alcohol-based film is not limited to this, but the degree of polymerization is preferably about 1,000 to 10,000, preferably 1,500 to 5,000. This is because when the degree of polymerization satisfies the above range, the molecular motion is free and can be mixed flexibly with iodine or dichroic dye.
  • polyvinyl alcohol-based film of the present invention a commercially available polyvinyl alcohol-based film may be used.
  • PS30, PE30, PE60 manufactured by Gurere, M2000, M3000 M6000, etc. may be used.
  • thermoplastic polyurethane film and the polyvinyl alcohol-based film is attached by a weak attraction generated on the surface of the thermoplastic polyurethane film and the unstretched polyvinyl alcohol-based film without a separate medium, or mediated adhesive Can be attached.
  • thermoplastic polyurethane film and the polyvinyl alcohol-based film When attaching the thermoplastic polyurethane film and the polyvinyl alcohol-based film by the attraction, it is possible to have a proper adhesion by performing a surface treatment on one or both surfaces of the thermoplastic polyurethane film or polyvinyl alcohol-based film.
  • the surface treatment may be performed through various surface treatment methods well known in the art, for example, corona treatment, plasma treatment, or surface modification treatment using a strong base aqueous solution such as NaOH or KOH.
  • the thickness of the adhesive layer before stretching is about 20 nm to 4000 nm, preferably about 20 nm to 1000 nm, and more preferably 20 nm to 500 nm. May be enough.
  • the thickness of the adhesive layer after the stretching of the film laminate may be about 10nm to 1000nm, preferably 10nm to 500nm, more preferably 10nm to 200nm.
  • the adhesive the material is not particularly limited, various adhesives known in the art can be used without limitation.
  • the adhesive layer may be formed of an aqueous adhesive or an ultraviolet curable adhesive.
  • the adhesive layer may be formed by an aqueous adhesive including at least one selected from the group consisting of polyvinyl alcohol-based resins, acrylic resins, and vinyl acetate-based resins.
  • the adhesive layer may be formed by an aqueous adhesive including a polyvinyl alcohol-based resin having an acrylic group and a hydroxyl group.
  • the polyvinyl alcohol-based resin having an acrylic group and a hydroxyl group may have a degree of polymerization of about 500 to 1800.
  • the adhesive layer may be formed using an aqueous adhesive including an amine-based metal compound crosslinking agent in acetacetyl group-containing polyvinyl alcohol-based resin.
  • the adhesive may be an aqueous solution containing 100 parts by weight of a polyvinyl alcohol-based resin containing an acetacetyl group and 1 to 50 parts by weight of an amine metal compound crosslinking agent.
  • the polymerization degree and saponification degree of the polyvinyl alcohol-based resin are not particularly limited as long as they contain acetacetyl group, but the polymerization degree is 200 to 4,000, and the saponification degree is preferably 70 mol% to 99.9 mol%.
  • the degree of polymerization is 1,500 to 2,500, and the degree of saponification is more preferably 90 mol% to 99.9 mol%.
  • the polyvinyl alcohol-based resin preferably comprises 0.1 to 30 mol% of the acetacetyl group.
  • the reaction with the amine-based metal compound crosslinking agent may be smooth, and may be sufficiently significant for the water resistance of the desired adhesive.
  • the amine-based metal compound crosslinking agent is a water-soluble crosslinking agent having a functional group having reactivity with the polyvinyl alcohol-based resin, preferably in the form of a metal complex containing an amine ligand.
  • Possible metals include zirconium (Zr), titanium (Ti), hafnium (Hf), tungsten (W), iron (Fe), cobalt (Co), nickel (Ni), ruthenium (Ru), osmium (Os), Transition metals such as rhodium (Rh), iridium (Ir), palladium (Pd) and platinum (Pt) are possible, and ligands bound to the central metal are primary amines, secondary amines (diamines), tertiary amines or ammonium hydrides. As long as it contains at least 1 or more amine groups, such as a lockside, it is all possible.
  • the solid content of the polyvinyl alcohol-based resin containing the acetacetyl group is preferably about 1% by weight to about 10% by weight. If the solid content of the polyvinyl alcohol-based resin is less than 1% by weight, the water resistance is not sufficiently secured, so that the effect of lowering the breakage rate in the stretching process is less. If the content is more than 10% by weight, the workability is deteriorated. This is because damage may occur on the alcohol-based film surface.
  • the pH of the adhesive is preferably 4.5 to 9 or so.
  • fills the said numerical range it is because it is more advantageous in storage property and durability in a high humidity environment.
  • the pH of the adhesive can be adjusted by the method of containing an acid in the aqueous solution, wherein the acid used for pH adjustment can be used both strong and weak acid.
  • the acid used for pH adjustment can be used both strong and weak acid.
  • nitric acid, hydrochloric acid, sulfuric acid or acetic acid and the like can be used.
  • the thickness of the adhesive layer formed by the above adhesive is about 80 nm to 200 nm, preferably about 80 nm to 150 nm before stretching the film laminate, and after stretching the film laminate, about 10 nm to 100 nm, preferably 10 nm to It is preferable that it is about 80 nm. This is because when the thickness of the adhesive layer satisfies the above range, the adhesion between the base film and the polyvinyl alcohol-based film is maintained at an appropriate level so that the breakage rate in the stretching process is reduced and the polarizer surface damage during peeling can be minimized. .
  • the said adhesive agent In the case of the said adhesive agent, a crosslinking reaction occurs between the amine type metal compound and the acetacetyl group of polyvinyl alcohol-type resin at the time of hardening, and the water resistance of the adhesive layer after hardening becomes very excellent. Therefore, when the polymer film and the polyvinyl alcohol-based film are laminated using the adhesive, the phenomenon in which the adhesive dissolves in water during wet stretching can be minimized, and thus it can be particularly useful when performing wet stretching. .
  • the adhesive layer may be formed of an ultraviolet curable adhesive, for example, a first epoxy compound having a glass transition temperature of homopolymer of 120 ° C. or more, a second epoxy compound having a glass transition temperature of homopolymer of 60 ° C. or less and It may be formed of an ultraviolet curable adhesive containing a cationic photopolymerization initiator.
  • the UV-curable adhesive is 100 parts by weight of the first epoxy compound having a glass transition temperature of the homopolymer of 120 °C or more, 30 to 100 parts by weight of the second epoxy compound having a glass transition temperature of the homopolymer of 60 °C or less and cationic photopolymerization It may include 0.5 to 20 parts by weight of the initiator.
  • an epoxy compound refers to a compound having one or more epoxy groups in a molecule, preferably a compound having two or more epoxy groups in a molecule, and is in the form of a monomer, a polymer, or a resin.
  • the concept includes all of the compounds.
  • the epoxy compound of the present invention may be in the form of a resin.
  • the glass transition temperature of the homopolymer is an epoxy compound of 120 °C or more can be used without particular limitation, for example, the alicyclic epoxy compound and the glass transition temperature of the homo polymer is 120 °C or more and / Or aromatic epoxy may be used as the first epoxy compound of the present invention.
  • Specific examples of the epoxy compound having a glass transition temperature of homopolymer of 120 ° C. or higher include 3,4-epoxycyclohexylmethyl-3,4′-epoxycyclohexanecarboxylate, vinylcyclohexenedioxide dicyclopentadiene dioxide, and bisepoxycyclo.
  • the first epoxy compound is more preferably the glass transition temperature of the homopolymer is about 120 °C to 200 °C.
  • the second epoxy compound may be used without particular limitation as long as the glass transition temperature of the homopolymer is an epoxy compound of 60 ° C. or less.
  • an alicyclic epoxy compound, an aliphatic epoxy compound, or the like may be used as the second epoxy compound.
  • alicyclic epoxy compound it is preferable to use a bifunctional epoxy compound, that is, a compound having two epoxies, and more preferably use a compound in which the two epoxy groups are both alicyclic epoxy groups. It is not limited.
  • the epoxy compound which has an aliphatic epoxy group which is not an alicyclic epoxy group can be illustrated.
  • polyglycidyl ether of aliphatic polyhydric alcohol Polyglycidyl ethers of alkylene oxide adducts of aliphatic polyhydric alcohols; Polyglycidyl ethers of polyester polyols of aliphatic polyhydric alcohols and aliphatic polyhydric carboxylic acids; Polyglycidyl ethers of aliphatic polyvalent carboxylic acids; Polyglycidyl ethers of polyester polycarboxylic acids of aliphatic polyhydric alcohols and aliphatic polyhydric carboxylic acids; Dimers, oligomers or polymers obtained by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate; Or oligomers or polymers obtained by vinyl polymerization of glycidyl acrylate or glycidyl me
  • aliphatic polyhydric alcohol for example, an aliphatic polyhydric alcohol having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms or 2 to 4 carbon atoms may be exemplified.
  • Ethylene glycol 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neo Pentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8- Aliphatic diols such as octanediol, 1,9-nonane
  • alkylene oxide of 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms can be exemplified, for example, ethylene jade Seeds, propylene oxide or butylene oxide and the like can be used.
  • aliphatic polyhydric carboxylic acid For example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, sumeric acid, azelaic acid, sebacic acid, dodecane diacid, 2-methyl succinic acid, 2-methyladipic acid, 3-methyladipic acid, 3-methylpentaneic acid, 2-methyloctanoic acid, 3,8-dimethyldecanediic acid, 3,7-dimethyldecanediic acid, 1,20-eicosamethylenedica Carboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1, 4-cyclohexanedicarboxylic acid, 1,4-dicarboxymethylenecyclohexane, 1,2,3-propylic acid, 1,
  • the second epoxy compound of the present invention may include one or more glycidyl ether groups, for example, 1,4-cyclohexanedimethanol diglycidyl ether, 1,4-butanediol diggle Cydyl ether, 1,6-hexanediol diglycidyl ether, neopentyl diglycidyl ether, resorcinol diglycidyl ether, diethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, One selected from the group consisting of trimethylolpropanetriglycidyl ether, n-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and o-cresyl glycidyl ether The above can be used as the second epoxy compound of the present invention.
  • the second epoxy compound has a glass transition temperature of about 0 ° C to 60 ° C of the homopolymer.
  • the present invention is not limited thereto, but in the present invention, it is preferable to use a combination of the first epoxy compound including at least one epoxidized aliphatic ring group and the second epoxy compound including at least one glycidyl ether group as the epoxy compound. Particularly preferred.
  • the stretching is performed at a temperature of 45 °C to 55 °C.
  • optical properties such as transmittance, polarization degree, and color are very excellent.
  • the stretching may be performed at a draw ratio of 5 times to 15 times, preferably 5 times to 10 times, and in consideration of optical properties, it is particularly preferable to carry out at a draw ratio of 6 times to 8 times.
  • the stretching may be carried out by wet stretching or dry stretching, but is not particularly limited, because when the wet stretching, the surface adhesion of the thermoplastic polyurethane film and polyvinyl alcohol-based film is stronger than dry stretching. It is more preferable in that stretching can be performed stably without a separate bonding means.
  • the stretching step at least one of the step of dyeing iodine and / or dichroic dye on the polyvinyl alcohol-based film and / or cross-linking the dyed iodine and / or dichroic dye to the polyvinyl alcohol-based film It may be performed together with the above steps.
  • the dyeing, crosslinking and stretching processes can be performed simultaneously.
  • the film laminate with the dyeing completed is immersed in an aqueous solution of boric acid, and stretched in an aqueous solution of boric acid.
  • the crosslinking step and the stretching step may be performed together.
  • the stretching step is particularly preferably carried out in an aqueous boric acid solution having a boric acid concentration of about 1 to 5%, preferably about 1 to 4%, more preferably about 1 to 3%. This is because when the stretching is performed in an aqueous boric acid solution satisfying the concentration range, the polarization degree of the polarizer is improved.
  • the stretching is preferably carried out so that the thickness of the polyvinyl alcohol-based film is less than 10 ⁇ m, for example, the thickness of the polyvinyl alcohol-based film is 1 ⁇ m to 10 ⁇ m, 3 ⁇ m to 10 ⁇ m or 1 ⁇ m It is preferable to carry out so that it becomes about 5 micrometers.
  • the stretching is preferably performed so that the width shrinkage of the polyvinyl alcohol-based film is about 30% to 80%, preferably about 60% to 80%. This is because when the width shrinkage ratio of the polyvinyl alcohol-based film satisfies the numerical range, excellent optical properties can be obtained.
  • the drying is not limited thereto, but considering the optical properties of the polarizer, it is preferable that the drying is performed at a temperature of about 20 ° C. to 100 ° C., more preferably about 40 ° C. to 90 ° C., and the drying time is 1 It is preferable that it is minutes to about 10 minutes.
  • the adhesion between the stretched polyvinyl alcohol-based film and the stretched polyurethane film after stretching of the film laminate is 2N / 2cm or less, preferably, about 0.1 to 2N / 2cm, more preferably 0.1 to 1N / 2cm May be enough.
  • the adhesion between the stretched polyurethane film and the stretched polyvinyl alcohol film satisfies the above range, surface damage can be minimized during the separation process.
  • the adhesive layer is formed between the polyvinyl alcohol-based film and the polyurethane film, the adhesive layer is stretched together by stretching, as well as the polyvinyl alcohol-based film and the polyurethane film.
  • the thickness of the layer is reduced to a level of 10 to 50% compared to before stretching, and as a result, the adhesion force between the polyvinyl alcohol-based film and the polyurethane film is lowered to 2N / 2 cm or less, thereby making it easy to separate.
  • the adhesive force is the adhesive force measured when the sample films of 2cm length is attached, a specific measuring method is shown in FIG.
  • the adhesion between the films as shown in Figure 1, after fixing the polyvinyl alcohol film (A) of the film laminate with a sample holder (H), with respect to the surface direction of the film laminate It refers to the size of the peel strength measured while peeling the polyvinyl alcohol film (A) from the polyurethane film (B) by applying a force in a vertical direction, wherein the measuring instrument is a texture analyzer (Stable Micro Systems, Inc.). : TA-XT Plus) was used.
  • the stretched polyvinyl alcohol-based film is separated from the thermoplastic polyurethane film.
  • the separation step may be performed by applying a weak peel force to the polyvinyl alcohol-based film or thermoplastic polyurethane film to leave both films.
  • the peel force is preferably 2N / 2cm or less, for example, may be 0.1 to 2N / 2cm, 0.1 to 1N / 2cm or so.
  • the peel force required to separate the polyvinyl alcohol-based film and the polymer film is very weak compared to the case of lamination using a coating or co-extrusion, the two films are easily separated without any other process or equipment. Not only that, but also the damage of the polyvinyl alcohol-based film in the separation process is very low, it shows very excellent optical performance.
  • the thin polarizer manufacturing method of the present invention as described above, sheet-to-sheet (sheet-to-sheet) process, sheet-to-roll process or roll well known in the art It may be carried out through a roll-to-roll process or the like.
  • the sheet-to-sheet process is a method of using a sheet-like film cut to a certain size with a raw film (ie, polyvinyl alcohol-based film and polyurethane film), the sheet-to-roll process is a raw film One uses a rolled film in which a long film is wound, and the other is a method of using a sheet-like film cut to a constant size.
  • a roll-to-roll process is a method of using a rolled film as a raw film. In view of the continuity and productivity of the process, it is particularly preferred to use a roll-to-roll process among these.
  • the manufacturing method of this invention adhere
  • the polyurethane film and the polyvinyl alcohol-based film may be rewound in a roll shape, and then the film laminate may be unwound from the rewound film laminate roll and introduced into the stretching process, or may be rewound. It can be added directly to the drawing process without.
  • a peeling means eg, a peeling roll
  • a peeling roll is inserted between the polyurethane film and the polyvinyl alcohol-based film to separate the interface between the polyurethane film and the polyvinyl alcohol-based film, and then the separated poly
  • the urethane film and the polyvinyl alcohol-based film may be carried out by a method of winding up different rolls.
  • the polarizer of the present invention produced by the method as described above is very thin, about 10 ⁇ m or less, for example, 1 ⁇ m to 10 ⁇ m, 3 ⁇ m to 10 ⁇ m, or 1 ⁇ m to 5 ⁇ m.
  • the unitary transmittance is about 40 to 45%, and the polarization degree is 99.0% or more, preferably 99.5% or more, and more preferably 99.7% or more.
  • the polarizer of this invention is very excellent in the uniformity of the polarization degree to the width direction.
  • the polarizer of the present invention has a standard deviation of the degree of polarization measured at ten points located at equal intervals along the width direction of the polarizer at 0.002% or less.
  • the uniformity in the polarization degree of the polarizer of the present invention is excellent in the uniformity in the heat shrinkage characteristics of the polyurethane film used as the base film is similar to the polyvinyl alcohol-based film is stretched over the entire width-direction region of the polyvinyl alcohol-based film This is because it can be made uniform.
  • a polarizing plate can be formed by laminating a transparent film on one side or both sides on the polarizer of the present invention as described above.
  • the transparent film various films used as a polarizer protective film or a retardation film in the art may be used without limitation.
  • a cellulose film, an acrylic film, a cycloolefin film, or the like may be used.
  • Lamination of the polarizer and the transparent film is not particularly limited, and may be performed using an adhesive or an adhesive well known in the art.
  • the pressure-sensitive adhesive or adhesive may be appropriately selected in consideration of the material of the transparent film to be used, for example, when using a TAC as a transparent film, an aqueous adhesive such as a polyvinyl alcohol-based adhesive may be used, When using an acrylic film, a COP film, etc. as a transparent film, photocuring or thermosetting adhesives, such as an acrylic adhesive and an epoxy adhesive, can be used.
  • the lamination method of the polarizer and the transparent film is not particularly limited, but is preferably made of a roll-to-roll method using a polarizer film roll and a transparent film roll in terms of productivity. Since a method of manufacturing a polarizing plate by laminating a polarizer and a transparent film in a roll-to-roll manner is well known in the art, a detailed description thereof will be omitted. Thus, when manufacturing a polarizing plate by a roll-to-roll system, a long rolled polarizing plate can be obtained.
  • the polarizing plate of the present invention in addition to the transparent film may further include another functional optical layer, such as a brightness enhancement film, a primer layer, a hard coating layer, an antiglare layer, an antireflection layer or an adhesive layer for adhesion with a liquid crystal panel.
  • another functional optical layer such as a brightness enhancement film, a primer layer, a hard coating layer, an antiglare layer, an antireflection layer or an adhesive layer for adhesion with a liquid crystal panel.
  • the formation method of these optical layers is not specifically limited, The well-known method well known in the art can be used.
  • the polarizing plate of the present invention has a very thin thickness compared to the conventional polarizing plate and has excellent optical properties, and thus may be usefully used in display devices such as liquid crystal display panels and organic light emitting display devices.
  • a 30-micrometer-thick polyvinyl alcohol film was attached to both sides of a 60-micrometer-thick polyurethane film to prepare a film laminate. Then, the film laminate was swelled for 15 seconds in a 25 ° C. pure solution, followed by a dyeing process for 60 seconds in a 0.3 wt% concentration and an iodine solution at 25 ° C. Then, the film laminate was washed for 15 seconds in a 1 wt% solution of boric acid, and then stretched 7 times in a 2 wt% solution of boric acid at 45 ° C. After stretching, after the complementary color process in a 5 wt% KI solution, the drying process was performed for 5 minutes in an 80 °C oven. Then, the polyurethane film and the polyvinyl alcohol film were separated to finally produce a thin polarizer having a thickness of 7.5 ⁇ m.
  • a thin polarizer was prepared in the same manner as in Example 1 except that the stretching process was performed in a 2 wt% solution of boric acid at 50 ° C.
  • a thin polarizer was prepared in the same manner as in Example 1 except that the stretching process was performed in a 2 wt% solution of boric acid at 55 ° C.
  • Optical properties such as the single transmittance, polarization degree, single color, and orthogonal color of the thin polarizers prepared in Examples 1 to 3 were measured with a JASCO V-7100 Spectrophotometer. The measurement results are shown in [Table 1].
  • the polarization degree is 99.5% or more, and the optical properties are excellent.
  • the stretching temperature is 50 ° C to 55 ° C
  • the polarization degree is 99.9. It can be seen that the optical properties are particularly excellent at more than%.
  • a 30-micrometer-thick polyvinyl alcohol film was attached to both sides of a 60-micrometer-thick polyurethane film to prepare a film laminate. Then, the film laminate was swelled for 15 seconds in a 25 ° C. pure solution, followed by a dyeing process for 60 seconds in a 0.27 wt% concentration and an iodine solution at 25 ° C. Then, the film laminate was washed for 15 seconds in a 1 wt% solution of boric acid, and then stretched 7 times in a 2 wt% solution of boric acid at 50 ° C. After stretching, after the complementary color process in a 5 wt% KI solution, the drying process was performed for 5 minutes in an 80 °C oven. Then, the polyurethane film and the polyvinyl alcohol film were separated to finally produce a thin polarizer having a thickness of 7.5 ⁇ m.
  • a thin polarizer was prepared in the same manner as in Example 4, except that the stretching process was performed in a 2.5 wt% solution of boric acid.
  • a thin polarizer was prepared in the same manner as in Example 4 except that the stretching process was performed in a 3.5 wt% solution of boric acid.
  • Optical properties such as the single transmittance, polarization degree, single color, and orthogonal color of the thin polarizers prepared in Examples 4 to 6 were measured with a JASCO V-7100 Spectrophotometer. The measurement results are shown in [Table 2].
  • a 30-micrometer-thick polyvinyl alcohol film was attached to both sides of a 60-micrometer-thick polyurethane film to prepare a film laminate. Then, the film laminate was swelled for 15 seconds in a 25 ° C. pure solution, followed by a dyeing process for 60 seconds in a 0.29 wt% concentration and an iodine solution at 25 ° C. Then, the film laminate was washed in a 1 wt% solution of boric acid for 15 seconds, and then a 6.5-fold stretching process was performed in a 2 wt% solution of boric acid at 50 ° C.
  • a thin polarizer was produced in the same manner as in Example 7, except that the draw ratio was increased to 7 times.
  • a thin polarizer was produced in the same manner as in Example 7 except that the draw ratio was 7.5 times.
  • a thin polarizer was prepared in the same manner as in Example 5 except that a polyethylene film having a thickness of 90 ⁇ m was used instead of a polyurethane film having a thickness of 60 ⁇ m.
  • a thin polarizer was prepared in the same manner as in Example 8 except that a polypropylene film having a thickness of 50 ⁇ m was used instead of a polyurethane film having a thickness of 60 ⁇ m.
  • a thin polarizer was prepared in the same manner as in Example 8 except that a polyethylene terephthalate film having a thickness of 40 ⁇ m was used instead of a polyurethane film having a thickness of 60 ⁇ m, but breakage occurred during stretching, and thus, the thin polarizer could not be manufactured.
  • Figure 2 is a photograph showing the state of the film laminate in the stretching process of the present Comparative Example 3.
  • a thin polarizer was prepared in the same manner as in Example 1 except that the stretching process was performed in a 40 wt% solution of boric acid at 2 wt%.
  • a thin polarizer was prepared in the same manner as in Example 1, except that the stretching process was performed in a 2 wt% solution of boric acid at 60 ° C.
  • Optical properties such as single transmittance, polarization degree, single color, and orthogonal color of the thin polarizers prepared by Comparative Examples 1 to 3, 4, and 5 were measured by a JASCO V-7100 Spectrophotometer. The measurement results are shown in [Table 4].

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Abstract

The present invention relates to a thin polarizer with excellent optical properties and a method for manufacturing the same. A method for manufacturing a thin polarizer according to the present invention comprises the steps of: forming a film laminate body by attaching an unstretched polyvinyl alcohol-based film onto at least one surface of a thermoplastic polyurethane film by means of an attractive force or an adhesive; stretching the film laminate at a temperature of 45°C to 55°C; and separating the thermoplastic polyurethane film and the polyvinyl alcohol-based film.

Description

광학 물성이 우수한 박형 편광자, 그 제조 방법, 이를 포함하는 편광판 및 디스플레이 장치Thin polarizer with excellent optical properties, manufacturing method thereof, polarizer and display device comprising same
본 발명은 박형 편광자, 그 제조 방법, 이를 포함하는 편광판 및 디스플레이 장치에 관한 것으로, 보다 구체적으로는, 광학 물성이 우수하고, 두께가 10㎛ 이하로 얇은 박형 편광자, 그 제조 방법, 이를 포함하는 편광판 및 디스플레이 장치에 관한 것이다.The present invention relates to a thin polarizer, a method for manufacturing the same, a polarizing plate and a display device including the same, more specifically, a thin polarizer having excellent optical properties and having a thickness of 10 μm or less, a manufacturing method thereof, and a polarizing plate including the same. And a display device.
편광판에 사용되는 편광자는 자연광 또는 임의의 편광을 특정 방향의 편광으로 만들기 위한 광학 소자로, 액정표시소자, 유기발광소자(OLED)와 같은 디스플레이 장치에 널리 이용되고 있다. 현재 상기 디스플레이 장치에 사용되는 편광자로는 요오드계 화합물 또는 이색성 염료를 함유하는 분자 사슬이 일정한 방향으로 배향된 폴리비닐알코올계 편광 필름이 일반적으로 사용되고 있다.The polarizer used in the polarizing plate is an optical element for making natural light or arbitrary polarization into a polarized light in a specific direction, and is widely used in a display device such as a liquid crystal display device and an organic light emitting device (OLED). Currently, as a polarizer used in the display device, a polyvinyl alcohol polarizing film in which molecular chains containing an iodine compound or a dichroic dye are oriented in a constant direction is generally used.
상기 폴리비닐알코올계 편광필름은 폴리비닐알코올계 필름에 요오드 또는 이색성 염료를 염착시킨 후, 일정 방향으로 연신하고 가교하는 방법에 의해 제조되고 있으며, 이때 상기 연신 공정은 붕산 수용액 또는 요오드 수용액과 같은 용액 상에서 수행되는 습식 연신 또는 대기 중에서 수행되는 건식 연신 등으로 수행될 수 있다. 그런데, 이와 같은 종래의 제조 공정에서, 파단 발생 없이 연신이 수행되기 위해서는, 연신 전의 폴리비닐알코올계 필름의 두께가 60㎛를 초과할 것이 요구된다. 연신 전 폴리비닐알코올계 필름의 두께가 60㎛ 이하일 경우, 폴리비닐알코올계 필름의 팽윤도가 높아지고, 얇은 두께로 인해 연신 공정에서 단위 면적 당 작용하는 모듈러스가 커져 파단이 쉽게 발생할 수 있기 때문이다.The polyvinyl alcohol polarizing film is prepared by a method of dyeing and crosslinking iodine or dichroic dye on a polyvinyl alcohol-based film, and stretching in a predetermined direction, wherein the stretching process is an aqueous solution of boric acid or an iodine solution. It may be performed by wet stretching performed in solution or dry stretching performed in air. By the way, in this conventional manufacturing process, in order for extending | stretching to be performed without a breakage generation, it is required that the thickness of the polyvinyl alcohol-type film before extending | stretching exceeds 60 micrometers. This is because when the thickness of the polyvinyl alcohol-based film before stretching is 60 μm or less, the swelling degree of the polyvinyl alcohol-based film is increased, and the thinness of the polyvinyl alcohol-based film increases the modulus acting per unit area in the stretching process, thereby easily causing breakage.
한편, 최근 디스플레이 장치들의 박형화 경향에 따라 편광판 역시 보다 얇은 두께를 가질 것이 요구되고 있다. 그러나 종래와 같이 연신 전 두께가 60㎛를 넘는 폴리비닐알코올계 필름을 사용할 경우에 편광자의 두께를 줄이는데 한계가 있다. 따라서, 보다 얇은 두께의 편광자를 제조하기 위한 연구들이 시도되고 있다.On the other hand, according to the trend of thinning of display devices, polarizers are also required to have a thinner thickness. However, when using a polyvinyl alcohol-based film having a thickness before stretching of more than 60 ㎛ as in the prior art there is a limit in reducing the thickness of the polarizer. Therefore, studies have been attempted to fabricate thinner polarizers.
한국공개특허 제2010-0071998호에는 기재층 상에 친수성 고분자층을 코팅하거나, 기재층 형성재와 친수성 고분자층 형성재를 공압출하여 제조되는 적층체를 이용하여 박형의 편광판을 제조하는 방법이 개시되어 있다. 그러나, 코팅이나 공압출법의 경우, 연신 후에 폴리비닐알코올층과 기재층의 분리가 쉽지 않고, 분리를 위해 높은 박리력이 요구되기 때문에, 분리 과정에서 폴리비닐알코올층이 손상되거나 변형되는 등의 문제가 발생하기 쉬우며, 그 결과 폴리비닐알코올 필름의 편광도 등의 광학 물성이 떨어진다는 문제점이 있었다. 또한, 코팅법이나 공압출법을 이용할 경우, 폴리비닐알코올 수지를 용융시킨 다음 압출하거나, 코팅액으로 제조한 후에 도포하는 방식으로 제조되기 때문에 압출 조건, 코팅 조건 또는 제막 조건에 따라 제조되는 폴리비닐알코올 필름의 물성이 변화되기 쉬워 최종적으로 제조된 폴리비닐알코올의 물성이 저하될 뿐 아니라, 균일한 물성을 구현하기도 어렵다. Korean Unexamined Patent Publication No. 2010-0071998 discloses a method of manufacturing a thin polarizing plate using a laminate prepared by coating a hydrophilic polymer layer on a substrate layer or co-extrusion of a substrate layer forming material and a hydrophilic polymer layer forming material. It is. However, in the case of coating or co-extrusion, since the separation of the polyvinyl alcohol layer and the base layer is not easy after stretching and a high peel force is required for the separation, the polyvinyl alcohol layer is damaged or deformed during the separation process. Problems tend to occur, and as a result, there is a problem that optical properties such as polarization degree of the polyvinyl alcohol film are inferior. In addition, when a coating method or a coextrusion method is used, the polyvinyl alcohol resin is manufactured by melting and extruding the polyvinyl alcohol resin or by applying the coating solution after coating and then applying the polyvinyl alcohol according to extrusion conditions, coating conditions or film forming conditions. The physical properties of the film tend to change, and not only the physical properties of the finally produced polyvinyl alcohol are lowered, but also it is difficult to realize uniform physical properties.
따라서, 얇으면서도, 우수한 광학 물성을 갖는 박형의 편광자를 제조할 필요가 있다. Therefore, it is necessary to manufacture the thin polarizer which is thin but has the outstanding optical physical property.
본 발명은 상기와 같은 문제점을 해결하기 위한 것으로, 단체 투과도가 40 ~ 45%, 편광도가 99.0% 이상으로 광학 물성이 우수하고, 두께가 10㎛ 이하로 얇은 폴리알코올비닐계 박형 편광자 및 그 제조 방법을 제공하고자 한다.The present invention is to solve the problems as described above, the polyalcohol-based thin polarizer having a single optical transmittance of 40 ~ 45%, a polarization degree of 99.0% or more, excellent in optical properties, and a thickness of 10㎛ or less and its manufacturing method To provide.
일 측면에서, 본 발명은 열가소성 폴리우레탄 필름의 적어도 일면에 인력 또는 접착제를 이용하여 미연신 폴리비닐알코올계 필름을 부착하여 필름 적층체를 형성하는 단계; 상기 필름 적층체를 45℃ 내지 55℃의 온도에서 연신하는 단계; 및 상기 폴리우레탄 필름과 폴리비닐알코올계 필름을 분리하는 단계를 포함하는 박형 편광자의 제조 방법을 제공한다.In one aspect, the present invention comprises the steps of attaching a non-stretched polyvinyl alcohol-based film to the at least one surface of the thermoplastic polyurethane film by using an attractive force or an adhesive to form a film laminate; Stretching the film laminate at a temperature of 45 ° C. to 55 ° C .; And it provides a method for producing a thin polarizer comprising the step of separating the polyurethane film and the polyvinyl alcohol-based film.
이때, 상기 미연신 폴리비닐알코올게 필름은 두께가 10㎛ 내지 60㎛ 정도인 것이 바람직하며, 상기 연신하는 단계는 붕산 농도가 1 내지 5%, 바람직하게는 1 내지 3%인 붕산 수용액에서 수행될 수 있다.At this time, the unstretched polyvinyl alcohol film is preferably 10㎛ to 60㎛ thickness, the stretching step is carried out in boric acid solution of boric acid concentration of 1 to 5%, preferably 1 to 3%. Can be.
또한, 상기 폴리우레탄 필름과 폴리비닐알코올계 필름을 분리하는 단계는 2N/2cm 이하의 박리력을 가하여 수행될 수 있다. In addition, the separating of the polyurethane film and the polyvinyl alcohol-based film may be performed by applying a peel force of 2N / 2cm or less.
또한, 본 발명의 박형 편광자의 제조 방법은, 상기 연신하는 단계 전에 상기 필름 적층체에 요오드 및 이색성 염료 중 적어도 하나를 염착시키는 단계를 더 포함하거나, 상기 연신하는 단계 후에 필름 적층체를 건조하는 단계를 더 포함할 수 있다.In addition, the manufacturing method of the thin polarizer of the present invention further comprises the step of dyeing at least one of iodine and dichroic dye on the film laminate before the stretching step, or drying the film laminate after the stretching step It may further comprise a step.
다른 측면에서, 본 발명은 두께가 10㎛ 이하이고, 단체 투과도가 40% 내지 45%이며, 편광도가 99.0% 이상이며, 편광자의 폭 방향을 따라 등간격으로 위치하는 10개의 점에서 측정된 편광도의 표준편차가 0.002% 이하인 박형 편광자, 이를 포함하는 편광판 및 디스플레이 장치를 제공한다. In another aspect, the present invention has a polarization degree measured at ten points having a thickness of 10 μm or less, a single transmittance of 40% to 45%, a degree of polarization of 99.0% or more, and positioned at equal intervals along the width direction of the polarizer. Provided are a thin polarizer having a standard deviation of 0.002% or less, a polarizing plate and a display device including the same.
본 발명의 제조 방법은 기재 필름 폴리우레탄 필름을 사용하고, 특정한 온도에서 연신을 수행함으로써, 공정 안정성이 우수할 뿐 아니라, 광학 물성이 우수한 박형 편광자를 제조할 수 있다. 본 발명의 제조 방법에 의해 제조된 박형 편광자는 두께가 10㎛ 이하로 매우 얇을 뿐 아니라, 단체 투과도, 편광도 및 색감 등의 광학 물성이 매우 우수하다. In the production method of the present invention, by using a base film polyurethane film and stretching at a specific temperature, not only the process stability is excellent, but also the thin polarizer excellent in the optical properties can be manufactured. The thin polarizer manufactured by the manufacturing method of this invention is not only very thin but 10 micrometers in thickness, and is excellent also in optical properties, such as a single transmittance, polarization degree, and color.
도 1은 질감 분석기(Texture Analyzer)를 이용한 부착력 측정 방법을 나타낸 모식도이다.1 is a schematic diagram showing a method for measuring adhesion using a texture analyzer (Texture Analyzer).
도 2는 비교예 4의 연신 공정에서 파단이 발생한 필름 적층체를 보여주는 사진이다. 2 is a photograph showing a film laminate in which breakage occurred in the stretching step of Comparative Example 4. FIG.
이하, 본 발명을 보다 구체적으로 설명하기로 한다. Hereinafter, the present invention will be described in more detail.
본 발명자들은 제조 공정에서 파단이 발생하지 않고, 10㎛ 이하로 매우 얇으면서도 광학 물성이 우수한 편광자를 제조하기 위해 오랜 연구를 거듭한 결과, 고분자 필름 상에 폴리비닐알코올계 필름을 약한 인력 또는 접착제를 이용하여 부착시킨 다음, 이를 연신함으로써 상기와 같은 목적을 달성할 수 있음을 알아내었으며, 이와 관련하여 한국특허출원 제 10-2012-0130576호 및 한국특허출원 제10-2012-0130577호를 기출원한 바 있다.The present inventors have conducted a long study to manufacture a polarizer having no optical breakage and excellent in optical properties even though the fracture does not occur in the manufacturing process, and as a result, a weak attraction or adhesive of a polyvinyl alcohol-based film on a polymer film It was found that the above object can be achieved by attaching the same, and stretching the same. In this regard, Korean Patent Application No. 10-2012-0130576 and Korean Patent Application No. 10-2012-0130577 I've done it.
또한, 본 발명자들은 추가적인 연구를 통해, 상기 기출원된 박형 편광자 제조 방법에 있어서, 고분자 필름으로 열가소성 폴리우레탄 필름을 사용하고, 특정 온도에서 연신을 수행함으로써, 다른 종류의 필름을 사용하는 경우에 비해 매우 우수한 광학 물성을 갖는 박형 편광자를 제조할 수 있음을 알아내고, 본 발명을 완성하였다. In addition, the present inventors conducted further studies in the above-described method for producing a thin polarizer, by using a thermoplastic polyurethane film as a polymer film and performing stretching at a specific temperature, compared to the case of using other types of films It was found out that a thin polarizer having very excellent optical properties could be produced and completed the present invention.
본 발명에 따른 박형 편광자 제조 방법은, 열가소성 폴리우레탄 필름의 적어도 일면에 인력 또는 접착제를 이용하여 미연신 폴리비닐알코올계 필름을 부착하여 필름 적층체를 형성하는 단계; 상기 필름 적층체를 45℃ 내지 55℃의 온도에서 연신하는 단계; 및 상기 폴리우레탄 필름과 폴리비닐알코올계 필름을 분리하는 단계를 포함한다.According to the present invention, a method of manufacturing a thin polarizer includes: attaching an unstretched polyvinyl alcohol-based film to at least one surface of a thermoplastic polyurethane film by using attraction force or an adhesive to form a film laminate; Stretching the film laminate at a temperature of 45 ° C. to 55 ° C .; And separating the polyurethane film and the polyvinyl alcohol-based film.
이때, 상기 열가소성 폴리우레탄 필름은 폴리비닐알코올계 필름이 파단되는 것을 방지하기 위한 것으로, 본 발명자들의 연구에 따르면, 폴리우레탄 필름을 기재 필름으로 사용할 경우, 다른 재질의 필름을 사용하는 경우에 비해 고배율 연신이 가능하며, 열 수축 특성이 폴리비닐알코올계 필름과 유사하여 건조 과정에서 연신된 폴리비닐알코올 필름의 폭 수축을 저해하지 않고, 원활한 폭 수축을 유도할 수 있기 때문에, 우수한 광학 특성을 갖는 박형 편광자를 제조할 수 있는 것으로 나타났다. In this case, the thermoplastic polyurethane film is to prevent the polyvinyl alcohol-based film from breaking, according to the research of the present inventors, when using a polyurethane film as a base film, compared with the case of using a film of a different material Stretching is possible, and since the heat shrinkage property is similar to the polyvinyl alcohol-based film, it can induce smooth width shrinkage without inhibiting the width shrinkage of the stretched polyvinyl alcohol film in the drying process, and thus has excellent optical properties. It has been shown that polarizers can be produced.
본 발명에서 사용가능한 폴리우레탄 필름은 45℃ 내지 55℃의 온도에서 최대 연신 배율이 5배 이상, 바람직하게는 8배 이상인 열가소성 폴리우레탄 필름이면 되고, 특별히 한정되는 것은 아니다. The polyurethane film usable in the present invention may be a thermoplastic polyurethane film having a maximum draw ratio of 5 times or more, preferably 8 times or more at a temperature of 45 ° C to 55 ° C, and is not particularly limited.
이때, 상기 폴리우레탄 필름은 그 두께가 20 내지 100㎛ 정도, 바람직하게는 30 내지 80㎛인 것이 좋다. 폴리우레탄 필름의 두께가 20㎛ 미만이면 파단 가능성이 높고, 100㎛ 초과하면 필름 적층체 형성 이후 연신 효율이 감소할 수 있기 때문이다.At this time, the polyurethane film has a thickness of about 20 to 100㎛, preferably 30 to 80㎛. This is because if the thickness of the polyurethane film is less than 20 µm, the breakage probability is high, and if it exceeds 100 µm, the stretching efficiency after the film laminate is formed may decrease.
다음으로, 상기 열가소성 폴리우레탄 필름에 부착되는 폴리비닐알코올계 필름은 그 두께가 10㎛ 내지 60㎛ 정도, 바람직하게는 10㎛ 내지 40㎛ 정도인 것이 좋다. 폴리비닐알코올계 필름의 두께가 60㎛를 초과할 경우, 연신하여도 10㎛ 이하의 두께를 구현하기 어렵고, 그 두께가 10㎛미만인 경우에는 연신 중 파단이 발생하기 쉽다.Next, the polyvinyl alcohol-based film attached to the thermoplastic polyurethane film has a thickness of about 10 μm to 60 μm, preferably 10 μm to 40 μm. When the thickness of the polyvinyl alcohol-based film exceeds 60㎛, it is difficult to achieve a thickness of less than 10㎛ even when stretched, when the thickness is less than 10㎛ tends to break during stretching.
한편, 상기 폴리비닐알코올계 필름은, 이로써 한정되는 것은 아니나, 중합도가 1,000 내지 10,000 정도, 바람직하게는 1,500 내지 5,000 정도인 것이 좋다. 중합도가 상기 범위를 만족할 때, 분자 움직임이 자유롭고, 요오드 또는 이색성 염료 등과 유연하게 혼합될 수 있기 때문이다. On the other hand, the polyvinyl alcohol-based film is not limited to this, but the degree of polymerization is preferably about 1,000 to 10,000, preferably 1,500 to 5,000. This is because when the degree of polymerization satisfies the above range, the molecular motion is free and can be mixed flexibly with iodine or dichroic dye.
한편, 본 발명의 폴리비닐알코올계 필름으로는 시판되는 폴리비닐알코올계 필름을 사용할 수 있으며, 예를 들면, 구라레 사의 PS30, PE30, PE60, 일본합성사의 M2000, M3000 M6000 등이 사용될 수 있다. Meanwhile, as the polyvinyl alcohol-based film of the present invention, a commercially available polyvinyl alcohol-based film may be used. For example, PS30, PE30, PE60 manufactured by Gurere, M2000, M3000 M6000, etc. may be used.
한편, 본 발명에 있어서, 상기 열가소성 폴리우레탄 필름과 폴리비닐알코올계 필름은 별도의 매개물 없이 열가소성 폴리우레탄 필름과 미연신 폴리비닐알코올계 필름의 표면에서 발생하는 약한 인력에 의해 부착되거나, 접착제를 매개로 하여 부착될 수 있다. On the other hand, in the present invention, the thermoplastic polyurethane film and the polyvinyl alcohol-based film is attached by a weak attraction generated on the surface of the thermoplastic polyurethane film and the unstretched polyvinyl alcohol-based film without a separate medium, or mediated adhesive Can be attached.
인력을 이용하여 상기 열가소성 폴리우레탄 필름과 폴리비닐알코올계 필름을 부착할 경우에는, 열가소성 폴리우레탄 필름이나 폴리비닐알코올계 필름의 일면 또는 양면에 표면처리를 수행함으로써 적절한 부착력을 가지도록 할 수 있다. 이때, 상기 표면처리는 당해 기술 분야에 잘 알려져 있는 다양한 표면처리 방법, 예를 들면, 코로나 처리, 플라즈마 처리 또는 NaOH나 KOH와 같은 강염기 수용액을 이용한 표면 개질 처리 등을 통해 수행될 수 있다. When attaching the thermoplastic polyurethane film and the polyvinyl alcohol-based film by the attraction, it is possible to have a proper adhesion by performing a surface treatment on one or both surfaces of the thermoplastic polyurethane film or polyvinyl alcohol-based film. In this case, the surface treatment may be performed through various surface treatment methods well known in the art, for example, corona treatment, plasma treatment, or surface modification treatment using a strong base aqueous solution such as NaOH or KOH.
한편, 접착제를 이용하여 미연신 고분자 필름과 미연신 폴리비닐알코올계 필름을 부착할 경우, 연신 전 접착제층의 두께는 20nm 내지 4000nm 정도, 바람직하게는 20nm 내지 1000nm 정도, 더 바람직하게는 20nm 내지 500nm 정도일 수 있다. 한편, 상기 필름 적층체의 연신 후 접착제층의 두께는 10nm 내지 1000nm 정도, 바람직하게는, 10nm 내지 500nm 정도, 더 바람직하게는, 10nm 내지 200nm 정도일 수 있다. 연신 전, 후의 접착제층의 두께가 상기 범위를 만족할 때, 연신 및 건조 공정 이후에 폴리비닐알코올계 필름을 손상 없이 박리하는데 유리하다.On the other hand, when the unstretched polymer film and the unstretched polyvinyl alcohol-based film are attached using an adhesive, the thickness of the adhesive layer before stretching is about 20 nm to 4000 nm, preferably about 20 nm to 1000 nm, and more preferably 20 nm to 500 nm. May be enough. On the other hand, the thickness of the adhesive layer after the stretching of the film laminate may be about 10nm to 1000nm, preferably 10nm to 500nm, more preferably 10nm to 200nm. When the thickness of the adhesive layer before and after stretching satisfies the above range, it is advantageous to peel the polyvinyl alcohol-based film without damage after the stretching and drying process.
한편, 상기 접착제는, 그 재질이 특별히 한정되는 것은 아니며, 당해 기술 분야에 알려진 다양한 접착제들이 제한없이 사용될 수 있다. 예를 들어, 상기 접착제층은 수계 접착제 또는 자외선 경화형 접착제로 형성될 수 있다. On the other hand, the adhesive, the material is not particularly limited, various adhesives known in the art can be used without limitation. For example, the adhesive layer may be formed of an aqueous adhesive or an ultraviolet curable adhesive.
보다 구체적으로, 상기 접착제층은 폴리비닐알코올계 수지, 아크릴계 수지 및 비닐아세테이트계 수지로 이루어진 군으로부터 선택된 1종 이상을 포함하는 수계 접착제에 의해 형성될 수 있다. More specifically, the adhesive layer may be formed by an aqueous adhesive including at least one selected from the group consisting of polyvinyl alcohol-based resins, acrylic resins, and vinyl acetate-based resins.
또는, 상기 접착제층은 아크릴기 및 히드록시기를 갖는 폴리비닐알코올계 수지를 포함하는 수계 접착제에 의해 형성될 수 있다. 이때, 상기 아크릴기 및 히드록시기를 갖는 폴리비닐알코올계 수지는 중합도가 500 내지 1800 정도일 수 있다. Alternatively, the adhesive layer may be formed by an aqueous adhesive including a polyvinyl alcohol-based resin having an acrylic group and a hydroxyl group. At this time, the polyvinyl alcohol-based resin having an acrylic group and a hydroxyl group may have a degree of polymerization of about 500 to 1800.
또는, 상기 접착층은, 아세트아세틸기 함유 폴리비닐알코올계 수지에 아민계 금속 화합물 가교제를 포함하는 수계 접착제를 이용하여 형성될 수 있다. 보다 구체적으로는, 상기 접착제는 아세트아세틸기를 함유하는 폴리비닐알코올계 수지 100중량부 및 아민계 금속 화합물 가교제 1 내지 50중량부를 포함하는 수용액일 수 있다.Alternatively, the adhesive layer may be formed using an aqueous adhesive including an amine-based metal compound crosslinking agent in acetacetyl group-containing polyvinyl alcohol-based resin. More specifically, the adhesive may be an aqueous solution containing 100 parts by weight of a polyvinyl alcohol-based resin containing an acetacetyl group and 1 to 50 parts by weight of an amine metal compound crosslinking agent.
여기서, 상기 폴리비닐알코올계 수지의 중합도 및 검화도는 아세트아세틸기를 함유하기만 하면 특별히 한정되지 않으나, 중합도가 200 ~ 4,000이며, 검화도가 70몰% ~ 99.9몰%인 것이 바람직하다. 분자 움직임의 자유로움에 따른 함유 물질과의 유연한 혼합을 고려하면 중합도는 1,500 ~ 2,500이며, 검화도는 90몰% ~ 99.9몰%인 것이 더욱 바람직하다. 이때, 상기 폴리비닐알코올계 수지는 상기 아세트아세틸기를 0.1 ~ 30몰%로 포함하는 것이 바람직하다. 상기한 범위에서 아민계 금속화합물 가교제와의 반응이 원활할 수 있으며, 목적하는 접착제의 내수성에 충분히 유의적일 수 있다.Here, the polymerization degree and saponification degree of the polyvinyl alcohol-based resin are not particularly limited as long as they contain acetacetyl group, but the polymerization degree is 200 to 4,000, and the saponification degree is preferably 70 mol% to 99.9 mol%. Considering flexible mixing with the containing material according to the freedom of molecular movement, the degree of polymerization is 1,500 to 2,500, and the degree of saponification is more preferably 90 mol% to 99.9 mol%. In this case, the polyvinyl alcohol-based resin preferably comprises 0.1 to 30 mol% of the acetacetyl group. In the above range, the reaction with the amine-based metal compound crosslinking agent may be smooth, and may be sufficiently significant for the water resistance of the desired adhesive.
상기 아민계 금속화합물 가교제는 상기 폴리비닐알코올계 수지와의 반응성을 갖는 관능기를 가지는 수용성 가교제로서 아민계 리간드를 함유하는 금속 착물 형태인 것이 바람직하다. 가능한 금속으로는 지르콘늄(Zr), 타이타늄(Ti), 하프늄(Hf), 텅스텐(W), 철(Fe), 코발트(Co), 니켈(Ni), 루테늄(Ru), 오스뮴(Os), 로듐(Rh), 이리듐(Ir), 팔라듐(Pd), 백금(Pt) 등의 전이 금속이 가능하며, 중심 금속에 결합된 리간드로는 일차아민, 이차아민(다이아민), 삼차아민 이나 암모늄하이드록사이드 등의 적어도 하나 이상의 아민기를 포함한 것이면 모두 가능하다.The amine-based metal compound crosslinking agent is a water-soluble crosslinking agent having a functional group having reactivity with the polyvinyl alcohol-based resin, preferably in the form of a metal complex containing an amine ligand. Possible metals include zirconium (Zr), titanium (Ti), hafnium (Hf), tungsten (W), iron (Fe), cobalt (Co), nickel (Ni), ruthenium (Ru), osmium (Os), Transition metals such as rhodium (Rh), iridium (Ir), palladium (Pd) and platinum (Pt) are possible, and ligands bound to the central metal are primary amines, secondary amines (diamines), tertiary amines or ammonium hydrides. As long as it contains at least 1 or more amine groups, such as a lockside, it is all possible.
또한, 상기 접착제에 있어서, 상기 아세트아세틸기를 함유하는 폴리비닐알코올계 수지의 고형분 함량은 1중량% 내지 10중량%정도인 것이 바람직하다. 폴리비닐알코올계 수지의 고형분 함량이 1중량% 미만인 경우에는 내수성이 충분히 확보되지 않아 연신 공정에서의 파단 발생율 저하 효과가 적고, 10중량%를 초과할 경우에는 작업성이 떨어지고, 박리 시에 폴리비닐알코올계 필름 표면에 손상이 발생할 수 있기 때문이다. In the adhesive, the solid content of the polyvinyl alcohol-based resin containing the acetacetyl group is preferably about 1% by weight to about 10% by weight. If the solid content of the polyvinyl alcohol-based resin is less than 1% by weight, the water resistance is not sufficiently secured, so that the effect of lowering the breakage rate in the stretching process is less. If the content is more than 10% by weight, the workability is deteriorated. This is because damage may occur on the alcohol-based film surface.
한편, 상기 접착제의 pH는 4.5 내지 9 정도인 것이 바람직하다. 접착제의 pH가 상기 수치 범위를 만족할 경우, 저장성, 고습 환경에서의 내구성에 있어서 보다 유리하기 때문이다. On the other hand, the pH of the adhesive is preferably 4.5 to 9 or so. When the pH of an adhesive agent satisfy | fills the said numerical range, it is because it is more advantageous in storage property and durability in a high humidity environment.
한편, 상기 접착제의 pH는 수용액 중에 산을 함유시키는 방법으로 조절할 수 있으며, 이때, 상기 pH 조절을 위해 사용되는 산은 강산 및 약산 모두 사용가능하다. 예를 들면, 질산, 염산, 황산 또는 아세트산 등이 사용될 수 있다. On the other hand, the pH of the adhesive can be adjusted by the method of containing an acid in the aqueous solution, wherein the acid used for pH adjustment can be used both strong and weak acid. For example, nitric acid, hydrochloric acid, sulfuric acid or acetic acid and the like can be used.
상기와 같은 접착제에 의해 형성되는 접착제층의 두께는 필름 적층체의 연신 전에는 80nm 내지 200nm 정도, 바람직하게는 80nm 내지 150nm 정도이고, 필름 적층체의 연신 후에는 10nm 내지 100nm 정도, 바람직하게는 10nm 내지 80nm 정도인 것이 바람직하다. 접착제층의 두께가 상기 범위를 만족할 경우, 기재 필름과 폴리비닐알코올계 필름의 접착력이 적절한 수준으로 유지되어 연신 공정에서의 파단 발생율이 저하되는 동시에 박리 시에 편광자 표면 손상을 최소화할 수 있기 때문이다.The thickness of the adhesive layer formed by the above adhesive is about 80 nm to 200 nm, preferably about 80 nm to 150 nm before stretching the film laminate, and after stretching the film laminate, about 10 nm to 100 nm, preferably 10 nm to It is preferable that it is about 80 nm. This is because when the thickness of the adhesive layer satisfies the above range, the adhesion between the base film and the polyvinyl alcohol-based film is maintained at an appropriate level so that the breakage rate in the stretching process is reduced and the polarizer surface damage during peeling can be minimized. .
상기 접착제의 경우, 경화 시에 아민계 금속 화합물과 폴리비닐알코올계 수지의 아세트아세틸기 사이에 가교 반응이 일어나, 경화 후 접착층의 내수성이 매우 우수해진다. 따라서, 상기 접착제를 이용하여 고분자 필름과 폴리비닐알코올계 필름을 적층할 경우, 습식 연신 시에 접착제가 물에 녹아나오는 현상을 최소화할 수 있어, 습식 연신을 수행하는 경우에 특히 유용하게 사용될 수 있다. In the case of the said adhesive agent, a crosslinking reaction occurs between the amine type metal compound and the acetacetyl group of polyvinyl alcohol-type resin at the time of hardening, and the water resistance of the adhesive layer after hardening becomes very excellent. Therefore, when the polymer film and the polyvinyl alcohol-based film are laminated using the adhesive, the phenomenon in which the adhesive dissolves in water during wet stretching can be minimized, and thus it can be particularly useful when performing wet stretching. .
한편, 상기 접착제층은, 자외선 경화형 접착제로 형성될 수도 있으며, 예를 들면, 호모폴리머의 유리전이온도가 120℃ 이상인 제1에폭시 화합물, 호모폴리머의 유리전이온도가 60℃ 이하인 제2에폭시 화합물 및 양이온성 광 중합 개시제를 포함하는 자외선 경화형 접착제로 형성될 수 있다. 구체적으로, 상기 자외선 경화형 접착제는 호모폴리머의 유리전이온도가 120℃ 이상인 제1에폭시 화합물 100 중량부, 호모폴리머의 유리전이온도가 60℃ 이하인 제2에폭시 화합물 30 내지 100 중량부 및 양이온성 광 중합 개시제 0.5 내지 20 중량부를 포함할 수 있다. Meanwhile, the adhesive layer may be formed of an ultraviolet curable adhesive, for example, a first epoxy compound having a glass transition temperature of homopolymer of 120 ° C. or more, a second epoxy compound having a glass transition temperature of homopolymer of 60 ° C. or less and It may be formed of an ultraviolet curable adhesive containing a cationic photopolymerization initiator. Specifically, the UV-curable adhesive is 100 parts by weight of the first epoxy compound having a glass transition temperature of the homopolymer of 120 ℃ or more, 30 to 100 parts by weight of the second epoxy compound having a glass transition temperature of the homopolymer of 60 ℃ or less and cationic photopolymerization It may include 0.5 to 20 parts by weight of the initiator.
본 명세서에서 에폭시 화합물은 분자 내에 1개 이상의 에폭시기를 갖는 화합물을 의미하는 것으로, 바람직하게는 분자 내에 2개 이상의 에폭시기를 갖는 화합물이며, 단량체(monomer), 중합체(polymer) 또는 수지(resin)의 형태의 화합물들을 모두 포함하는 개념이다. 바람직하게는 본 발명의 에폭시 화합물은 수지 형태일 수 있다. As used herein, an epoxy compound refers to a compound having one or more epoxy groups in a molecule, preferably a compound having two or more epoxy groups in a molecule, and is in the form of a monomer, a polymer, or a resin. The concept includes all of the compounds. Preferably the epoxy compound of the present invention may be in the form of a resin.
한편, 상기 제1에폭시 화합물로는, 호모폴리머의 유리전이온도가 120℃ 이상인 에폭시 화합물이면 특별한 제한 없이 사용될 수 있으며, 예를 들면, 호모 폴리머의 유리전이온도가 120℃ 이상인 지환족 에폭시 화합물 및/또는 방향족 에폭시가 본 발명의 제1에폭시 화합물로 사용될 수 있다. 호모폴리머의 유리전이온도가 120℃ 이상인 에폭시 화합물의 구체적인 예로는, 3,4-에폭시시클로헥실메틸-3,4'-에폭시시클로헥산카복실레이트, 비닐사이클로헥센디옥사이드 디시클로펜타디엔디옥사이드, 비스에폭시사이클로펜틸에테르, 비스페놀 A 계 에폭시 화합물, 비스페놀 F 계 에폭시 화합물 등을 들 수 있다. 한편, 상기 제1에폭시 화합물은 호모폴리머의 유리전이온도가 120℃ 내지 200℃ 정도인 것이 보다 바람직하다.On the other hand, as the first epoxy compound, if the glass transition temperature of the homopolymer is an epoxy compound of 120 ℃ or more can be used without particular limitation, for example, the alicyclic epoxy compound and the glass transition temperature of the homo polymer is 120 ℃ or more and / Or aromatic epoxy may be used as the first epoxy compound of the present invention. Specific examples of the epoxy compound having a glass transition temperature of homopolymer of 120 ° C. or higher include 3,4-epoxycyclohexylmethyl-3,4′-epoxycyclohexanecarboxylate, vinylcyclohexenedioxide dicyclopentadiene dioxide, and bisepoxycyclo. A pentyl ether, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, etc. are mentioned. On the other hand, the first epoxy compound is more preferably the glass transition temperature of the homopolymer is about 120 ℃ to 200 ℃.
다음으로, 상기 제2에폭시 화합물은, 호모폴리머의 유리전이온도가 60℃ 이하인 에폭시 화합물이면 특별한 제한 없이 사용될 수 있다. 예를 들면, 상기 제2에폭시 화합물로 지환족 에폭시 화합물, 지방족 에폭시 화합물 등이 사용될 수 있다.Next, the second epoxy compound may be used without particular limitation as long as the glass transition temperature of the homopolymer is an epoxy compound of 60 ° C. or less. For example, an alicyclic epoxy compound, an aliphatic epoxy compound, or the like may be used as the second epoxy compound.
이때, 상기 지환족 에폭시 화합물로는, 2관능형 에폭시 화합물, 즉 2개의 에폭시를 가지는 화합물을 사용하는 것이 바람직하고, 상기 2개의 에폭시기가 모두 지환식 에폭시기인 화합물을 사용하는 것이 보다 바람직하지만, 이에 제한되는 것은 아니다.In this case, as the alicyclic epoxy compound, it is preferable to use a bifunctional epoxy compound, that is, a compound having two epoxies, and more preferably use a compound in which the two epoxy groups are both alicyclic epoxy groups. It is not limited.
지방족 에폭시 화합물로는, 지환족 에폭시기가 아닌 지방족 에폭시기를 가지는 에폭시 화합물이 예시될 수 있다. 예를 들면, 지방족 다가 알코올의 폴리글리시딜에테르; 지방족 다가 알코올의 알킬렌옥시드 부가물의 폴리글리시딜에테르; 지방족 다가 알코올과 지방족 다가 카복실산의 폴리에스테르 폴리올의 폴리글리시딜에테르; 지방족 다가 카복실산의 폴리글리시딜에테르; 지방족 다가 알코올과 지방족 다가 카복실산의 폴리에스테르 폴리카복실산의 폴리글리시딜에테르; 글리시딜 아크릴레이트 또는 글리시딜 메타크릴레이트의 비닐 중합에 의해 얻어지는 다이머, 올리고머 또는 폴리머; 또는 글리시딜 아크릴레이트 또는 글리시딜 메타크릴레이트와 다른 비닐계 단량체의 비닐 중합에 의해 얻어지는 올리고머 또는 폴리머가 예시될 수 있고, 바람직하게는 지방족 다가 알코올 또는 그 알킬렌옥시드 부가물의 폴리글리시딜에테르가 사용될 수 있으나, 이에 제한되는 것은 아니다.As an aliphatic epoxy compound, the epoxy compound which has an aliphatic epoxy group which is not an alicyclic epoxy group can be illustrated. For example, polyglycidyl ether of aliphatic polyhydric alcohol; Polyglycidyl ethers of alkylene oxide adducts of aliphatic polyhydric alcohols; Polyglycidyl ethers of polyester polyols of aliphatic polyhydric alcohols and aliphatic polyhydric carboxylic acids; Polyglycidyl ethers of aliphatic polyvalent carboxylic acids; Polyglycidyl ethers of polyester polycarboxylic acids of aliphatic polyhydric alcohols and aliphatic polyhydric carboxylic acids; Dimers, oligomers or polymers obtained by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate; Or oligomers or polymers obtained by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate with other vinyl monomers, preferably polyglycidyl of aliphatic polyhydric alcohols or their alkylene oxide adducts. Ether may be used, but is not limited thereto.
상기에서 지방족 다가 알코올로는, 예를 들면, 탄소수 2 내지 20, 탄소수 2 내지 16, 탄소수 2 내지 12, 탄소수 2 내지 8 또는 탄소수 2 내지 4의 지방족 다가 알코올이 예시될 수 있고, 예를 들면, 에틸렌글리콜, 1,2-프로판디올, 1,3-프로판디올, 2-메틸-1,3-프로판디올, 2-부틸-2-에틸-1,3-프로판디올, 1,4-부탄디올, 네오펜틸글리콜, 3-메틸-2,4-펜탄디올, 2,4-펜탄디올, 1,5-펜탄디올, 3-메틸-1,5-펜탄디올, 2-메틸-2,4-펜탄디올, 2,4-디에틸-1,5-펜탄디올, 1,6-헥산디올, 1,7-헵탄디올, 3,5-헵탄디올, 1,8-옥탄디올, 2-메틸-1,8-옥탄디올, 1,9-노난디올, 1,10-데칸디올 등의 지방족 디올; 시클로헥산디메탄올, 시클로헥산디올, 수소 첨가 비스페놀 A, 수소 첨가 비스페놀 F 등의 지환식 디올; 트리메틸올에탄, 트리메틸올프로판, 헥시톨류, 펜티톨류, 글리세린, 폴리글리세린, 펜타에리스리톨, 디펜타에리스리톨, 테트라메틸올프로판 등이 예시될 수 있다.As the aliphatic polyhydric alcohol, for example, an aliphatic polyhydric alcohol having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms or 2 to 4 carbon atoms may be exemplified. Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neo Pentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8- Aliphatic diols such as octanediol, 1,9-nonanediol and 1,10-decanediol; Alicyclic diols such as cyclohexanedimethanol, cyclohexanediol, hydrogenated bisphenol A and hydrogenated bisphenol F; Trimethylol ethane, trimethylol propane, hexitols, pentitols, glycerin, polyglycerol, pentaerythritol, dipentaerythritol, tetramethylol propane and the like can be exemplified.
또한, 상기에서 알킬렌옥시드로는, 탄소수 1 내지 20, 탄소수 1 내지 16, 탄소수 1 내지 12, 탄소수 1 내지 8 또는 탄소수 1 내지 4의 알킬렌옥시드가 예시될 수 있고, 예를 들면, 에틸렌옥시드, 프로필렌옥시드 또는 부틸렌옥시드 등이 사용될 수 있다.In addition, as the alkylene oxide in the above, alkylene oxide of 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms can be exemplified, for example, ethylene jade Seeds, propylene oxide or butylene oxide and the like can be used.
또한, 상기 지방족 다가 카복실산으로는, 예를 들면, 옥살산, 말론산, 숙신산, 글루타르산, 아디프산, 피멜산, 수베린산, 아젤라산, 세바신산, 도데칸이산, 2-메틸숙신산, 2-메틸아디프산, 3-메틸아디프산, 3-메틸펜탄이산, 2-메틸옥탄이산, 3,8-디메틸데칸이산, 3,7-디메틸데칸이산, 1,20-에이코사메틸렌디카르복실산, 1,2-시클로펜탄디카르복실산, 1,3-시클로펜탄디카르복실산, 1,2-시클로헥산디카르복실산, 1,3-시클로헥산디카르복실산, 1,4-시클로헥산디카르복실산, 1,4-디카르복실메틸렌시클로헥산, 1,2,3-프로판트리카르복실산, 1,2,3,4-부탄테트라카르복실산, 1,2,3,4-시클로부탄테트라카르복실산 등이 예시될 수 있으나, 이에 제한되는 것은 아니다.Moreover, as said aliphatic polyhydric carboxylic acid, For example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, sumeric acid, azelaic acid, sebacic acid, dodecane diacid, 2-methyl succinic acid, 2-methyladipic acid, 3-methyladipic acid, 3-methylpentaneic acid, 2-methyloctanoic acid, 3,8-dimethyldecanediic acid, 3,7-dimethyldecanediic acid, 1,20-eicosamethylenedica Carboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1, 4-cyclohexanedicarboxylic acid, 1,4-dicarboxymethylenecyclohexane, 1,2,3-propanetricarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 1,2, 3,4-cyclobutanetetracarboxylic acid and the like can be exemplified, but is not limited thereto.
바람직하게는, 본 발명의 상기 제2에폭시 화합물은 글리시딜 에테르기를 하나 이상 포함하는 것일 수 있으며, 예를 들면, 1,4-시클로헥산디메탄올 디글리시딜 에테르, 1,4-부탄디올디글시딜에테르, 1,6-헥산디올디글리시딜에테르, 네오펜틸디글시딜에테르, 레조시놀디글리시딜에테르, 디에틸렌글라이콜디글리시딜에테르, 에틸렌글라이콜디글리시딜에테르, 트리메틸올프로판트리글리시딜에테르, n-부틸 글리시딜 에테르, 2-에틸헥실 글리시딜 에테르, 페닐 글리시딜 에테르, 및 o-크레실(Cresyl) 글리시딜 에테르로 이루어진 그룹으로부터 선택된 1종 이상이 본 발명의 제2에폭시 화합물로 사용될 수 있다. Preferably, the second epoxy compound of the present invention may include one or more glycidyl ether groups, for example, 1,4-cyclohexanedimethanol diglycidyl ether, 1,4-butanediol diggle Cydyl ether, 1,6-hexanediol diglycidyl ether, neopentyl diglycidyl ether, resorcinol diglycidyl ether, diethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, One selected from the group consisting of trimethylolpropanetriglycidyl ether, n-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and o-cresyl glycidyl ether The above can be used as the second epoxy compound of the present invention.
한편, 상기 제2에폭시 화합물은 호모폴리머의 유리전이온도가 0℃ 내지 60℃ 정도인 것이 보다 바람직하다On the other hand, it is more preferred that the second epoxy compound has a glass transition temperature of about 0 ° C to 60 ° C of the homopolymer.
한편, 이로써 한정되는 것은 아니나, 본 발명의 경우, 상기 에폭시 화합물로 에폭시화 지방족 고리기를 하나 이상 포함하는 제1에폭시 화합물 및 글리시딜에테르기를 하나 이상 포함하는 제2에폭시 화합물의 조합을 사용하는 것이 특히 바람직하다. Meanwhile, the present invention is not limited thereto, but in the present invention, it is preferable to use a combination of the first epoxy compound including at least one epoxidized aliphatic ring group and the second epoxy compound including at least one glycidyl ether group as the epoxy compound. Particularly preferred.
다음으로, 상기 필름 적층체를 연신하는 단계에 있어서, 상기 연신은 45℃ 내지 55℃의 온도에서 수행된다. 본 발명자들의 연구에 따르면, 기재 필름으로 열가소성 폴리우레탄 필름을 사용하고, 연신 온도에서 연신을 수행할 경우, 투과도, 편광도 및 색감 등의 광학 물성이 매우 우수하게 나타나는 것으로 밝혀졌다.Next, in the stretching of the film laminate, the stretching is performed at a temperature of 45 ℃ to 55 ℃. According to the researches of the present inventors, when the thermoplastic polyurethane film is used as the base film and the stretching is performed at the stretching temperature, optical properties such as transmittance, polarization degree, and color are very excellent.
한편, 상기 연신은 5배 내지 15배, 바람직하게는 5배 내지 10배의 연신 배율로 수행될 수 있으며, 광학 물성을 고려할 때, 6배 내지 8배의 연신 배율로 수행되는 것이 특히 바람직하다.On the other hand, the stretching may be performed at a draw ratio of 5 times to 15 times, preferably 5 times to 10 times, and in consideration of optical properties, it is particularly preferable to carry out at a draw ratio of 6 times to 8 times.
한편, 상기 연신은 습식 연신 또는 건식 연신으로 수행될 수 있으며, 특별히 제한되는 것은 아니나, 습식 연신을 실시하는 경우, 건식 연신에 비해 열가소성 폴리우레탄 필름과 폴리비닐알코올계 필름의 표면 부착력이 강해지기 때문에 별도의 접착 수단이 없이 안정적으로 연신을 수행할 수 있다는 점에서 보다 바람직하다.On the other hand, the stretching may be carried out by wet stretching or dry stretching, but is not particularly limited, because when the wet stretching, the surface adhesion of the thermoplastic polyurethane film and polyvinyl alcohol-based film is stronger than dry stretching. It is more preferable in that stretching can be performed stably without a separate bonding means.
한편, 상기 연신 단계는, 폴리비닐알코올계 필름에 요오드 및/또는 이색성 염료를 염착시키는 단계 및/또는 상기 염착된 요오드 및/또는 이색성 염료를 폴리비닐알코올계 필름에 가교시키는 단계 중 적어도 하나 이상의 단계와 함께 수행될 수 있다. On the other hand, the stretching step, at least one of the step of dyeing iodine and / or dichroic dye on the polyvinyl alcohol-based film and / or cross-linking the dyed iodine and / or dichroic dye to the polyvinyl alcohol-based film It may be performed together with the above steps.
예를 들면, 상기 연신을 요오드 및/또는 이색성 염료와 붕산을 포함하는 수용액 내에서 수행함으로써, 염착, 가교 및 연신 공정을 동시에 수행할 수 있다. 또는, 상기 연신 단계 전에 필름 적층체를 요오드 및/또는 이색성 염료를 포함하는 수용액에 침지시켜 염착 단계를 수행한 후에, 상기 염착이 완료된 필름 적층체를 붕산 수용액에 침지시키고, 붕산 수용액 내에서 연신을 수행함으로써, 가교 단계와 연신 단계를 함께 수행할 수도 있다. For example, by performing the stretching in an aqueous solution containing iodine and / or dichroic dyes and boric acid, the dyeing, crosslinking and stretching processes can be performed simultaneously. Alternatively, after performing the dyeing step by immersing the film laminate in an aqueous solution containing iodine and / or dichroic dye before the stretching step, the film laminate with the dyeing completed is immersed in an aqueous solution of boric acid, and stretched in an aqueous solution of boric acid. By carrying out, the crosslinking step and the stretching step may be performed together.
한편, 상기 연신 단계는 붕산 농도가 1 내지 5% 정도, 바람직하게는 1 내지 4% 정도, 더 바람직하게는, 1 내지 3% 정도인 붕산 수용액에서 수행되는 것이 특히 바람직하다. 상기 농도 범위를 만족하는 붕산 수용액에서 연신을 수행할 경우, 편광자의 편광도가 향상되는 효과가 있기 때문이다. On the other hand, the stretching step is particularly preferably carried out in an aqueous boric acid solution having a boric acid concentration of about 1 to 5%, preferably about 1 to 4%, more preferably about 1 to 3%. This is because when the stretching is performed in an aqueous boric acid solution satisfying the concentration range, the polarization degree of the polarizer is improved.
한편, 상기 연신은 폴리비닐알코올계 필름의 두께가 10㎛이하가 되도록 수행하는 것이 바람직하며, 예를 들면, 폴리비닐알코올계 필름의 두께가 1㎛ 내지 10㎛, 3㎛ 내지 10㎛ 또는 1㎛ 내지 5㎛ 정도가 되도록 수행하는 것이 바람직하다.  On the other hand, the stretching is preferably carried out so that the thickness of the polyvinyl alcohol-based film is less than 10㎛, for example, the thickness of the polyvinyl alcohol-based film is 1㎛ to 10㎛, 3㎛ to 10㎛ or 1㎛ It is preferable to carry out so that it becomes about 5 micrometers.
또한, 상기 연신은 폴리비닐알코올계 필름의 폭 수축율은 30% 내지 80% 정도, 바람직하게는 60% 내지 80% 정도가 되도록 수행되는 것이 바람직하다. 폴리비닐알코올계 필름의 폭 수축율이 상기 수치 범위를 만족할 경우, 우수한 광학 물성을 얻을 수 있기 때문이다. In addition, the stretching is preferably performed so that the width shrinkage of the polyvinyl alcohol-based film is about 30% to 80%, preferably about 60% to 80%. This is because when the width shrinkage ratio of the polyvinyl alcohol-based film satisfies the numerical range, excellent optical properties can be obtained.
한편, 상기 연신 단계 이후에 필요에 따라, 상기 필름 적층체를 건조하는 단계를 수행할 수 있다. 이때, 상기 건조는, 이로써 한정되는 것은 아니나, 편광자의 광학 특성을 고려할 때, 20℃ 내지 100℃, 더 바람직하게는 40℃ 내지 90℃ 정도의 온도에서 수행되는 것이 바람직하며, 상기 건조 시간은 1분 내지 10분 정도인 것이 바람직하다. On the other hand, after the stretching step, if necessary, it is possible to perform the step of drying the film laminate. At this time, the drying is not limited thereto, but considering the optical properties of the polarizer, it is preferable that the drying is performed at a temperature of about 20 ° C. to 100 ° C., more preferably about 40 ° C. to 90 ° C., and the drying time is 1 It is preferable that it is minutes to about 10 minutes.
한편, 상기 필름 적층체의 연신 후에 연신 폴리비닐알코올계 필름과 연신된 폴리우레탄 필름 사이의 부착력은 2N/2cm 이하, 바람직하게는, 0.1 내지 2N/2cm 정도, 더 바람직하게는 0.1 내지 1N/2cm 정도일 수 있다. 연신 폴리우레탄 필름과 연신 폴리비닐알코올 필름 사이의 부착력이 상기 범위를 만족할 경우, 분리 과정에서 표면 손상을 최소화할 수 있기 때문이다. 본 발명의 제조 방법에 따르면, 폴리비닐알코올계 필름과 폴리우레탄 필름 사이에 접착제층이 형성되어 있는 경우, 연신에 의해 폴리비닐알코올계 필름과 폴리우레탄 필름뿐 아니라 접착제층도 함께 연신되기 때문에, 접착제층의 두께가 연신 전 대비 10 ~ 50% 수준으로 감소하게 되며, 그 결과 폴리비닐알코올계 필름과 폴리우레탄 필름 사이의 부착력이 2N/2cm 이하로 저하되어 분리하기 쉬운 상태가 된다. 한편, 상기 부착력은 2cm 길이의 샘플 필름들을 부착하였을 때 측정되는 부착력이며, 구체적인 측정 방법은 도 1에 도시되어 있다. 본 발명에 있어서, 상기 필름들 사이의 부착력은, 도 1에 도시된 바와 같이, 필름 적층체의 폴리비닐알코올 필름(A)을 샘플 홀더(H)로 고정한 후, 필름 적층체의 면 방향에 대해 수직한 방향으로 힘을 가하여 폴리우레탄 필름(B)으로부터 폴리비닐알코올 필름(A)을 박리하면서 측정한 박리력(Peel Strength)의 크기를 말하며, 이때 측정 기기로는 Stable Micro Systems사의 Texture Analyzer (모델명: TA-XT Plus)를 사용하였다. On the other hand, the adhesion between the stretched polyvinyl alcohol-based film and the stretched polyurethane film after stretching of the film laminate is 2N / 2cm or less, preferably, about 0.1 to 2N / 2cm, more preferably 0.1 to 1N / 2cm May be enough. This is because when the adhesion between the stretched polyurethane film and the stretched polyvinyl alcohol film satisfies the above range, surface damage can be minimized during the separation process. According to the production method of the present invention, when the adhesive layer is formed between the polyvinyl alcohol-based film and the polyurethane film, the adhesive layer is stretched together by stretching, as well as the polyvinyl alcohol-based film and the polyurethane film. The thickness of the layer is reduced to a level of 10 to 50% compared to before stretching, and as a result, the adhesion force between the polyvinyl alcohol-based film and the polyurethane film is lowered to 2N / 2 cm or less, thereby making it easy to separate. On the other hand, the adhesive force is the adhesive force measured when the sample films of 2cm length is attached, a specific measuring method is shown in FIG. In the present invention, the adhesion between the films, as shown in Figure 1, after fixing the polyvinyl alcohol film (A) of the film laminate with a sample holder (H), with respect to the surface direction of the film laminate It refers to the size of the peel strength measured while peeling the polyvinyl alcohol film (A) from the polyurethane film (B) by applying a force in a vertical direction, wherein the measuring instrument is a texture analyzer (Stable Micro Systems, Inc.). : TA-XT Plus) was used.
다음으로, 상기 연신된 폴리비닐알코올계 필름을 상기 열가소성 폴리우레탄 필름으로부터 분리한다. 상기 분리 단계는 폴리비닐알코올계 필름 또는 열가소성 폴리우레탄 필름에 약한 박리력을 가하여 양 필름을 이탈시키는 방법으로 수행될 수 있다. 이때, 상기 박리력은 2N/2cm 이하인 것이 바람직하며, 예를 들면, 0.1 내지 2N/2cm, 0.1 내지 1N/2cm 정도일 수 있다. 이와 같이, 본 발명의 경우, 코팅이나 공압출을 이용하여 적층된 경우에 비해, 폴리비닐알코올계 필름과 고분자 필름을 분리하는데 요구되는 박리력이 매우 약하기 때문에 별다른 공정이나 장비 없이도 두 필름을 쉽게 분리할 수 있을 뿐 아니라, 분리 공정에서 폴리비닐알코올계 필름의 손상이 적어 매우 우수한 광학 성능을 나타낸다.Next, the stretched polyvinyl alcohol-based film is separated from the thermoplastic polyurethane film. The separation step may be performed by applying a weak peel force to the polyvinyl alcohol-based film or thermoplastic polyurethane film to leave both films. At this time, the peel force is preferably 2N / 2cm or less, for example, may be 0.1 to 2N / 2cm, 0.1 to 1N / 2cm or so. As described above, in the case of the present invention, since the peel force required to separate the polyvinyl alcohol-based film and the polymer film is very weak compared to the case of lamination using a coating or co-extrusion, the two films are easily separated without any other process or equipment. Not only that, but also the damage of the polyvinyl alcohol-based film in the separation process is very low, it shows very excellent optical performance.
한편, 상기와 같은 본 발명의 박형 편광자 제조 방법은, 당해 기술 분야에 잘 알려져 있는 시트-투-시트(sheet-to-sheet) 공정, 시트-투-롤(sheet-to-roll) 공정 또는 롤-투-롤(roll-to-roll) 공정 등을 통해 수행될 수 있다. 이때, 시트-투-시트 공정은 원료 필름(즉, 폴리비닐알코올계 필름 및 폴리우레탄 필름)으로 일정한 크기로 재단되어 있는 매엽형 필름을 사용하는 방법이며, 시트-투-롤 공정은 원료 필름 중 하나로는 길이가 긴 필름이 권취된 롤형 필름을 사용하고, 다른 원료 필름으로는 일정한 크기로 재단되어 있는 매엽형 필름을 사용하는 방법을 말한다. 또한, 롤-투-롤 공정은 원료 필름으로 롤형 필름을 사용하는 방법이다. 공정의 연속성 및 생산성을 고려할 때, 이 중에서도 롤-투-롤 공정을 사용하는 것이 특히 바람직하다. On the other hand, the thin polarizer manufacturing method of the present invention as described above, sheet-to-sheet (sheet-to-sheet) process, sheet-to-roll process or roll well known in the art It may be carried out through a roll-to-roll process or the like. At this time, the sheet-to-sheet process is a method of using a sheet-like film cut to a certain size with a raw film (ie, polyvinyl alcohol-based film and polyurethane film), the sheet-to-roll process is a raw film One uses a rolled film in which a long film is wound, and the other is a method of using a sheet-like film cut to a constant size. In addition, a roll-to-roll process is a method of using a rolled film as a raw film. In view of the continuity and productivity of the process, it is particularly preferred to use a roll-to-roll process among these.
예를 들면, 본 발명의 제조 방법은, 폴리우레탄 필름 롤과 폴리비닐알코올계 필름 롤로부터 폴리비닐알코올계 필름과 폴리우레탄 필름을 권출하면서 폴리우레탄 필름과 폴리비닐알코올계 필름을 부착시켜 필름 적층체를 형성하는 단계, 및 상기 필름 적층체를 45℃ 내지 55℃의 온도에서 연신하는 단계; 및 상기 열가소성 폴리우레탄 필름과 폴리비닐알코올계 필름을 분리하는 단계를 포함할 수 있다. For example, the manufacturing method of this invention adhere | attaches a polyurethane film and a polyvinyl alcohol-type film, unwinding a polyvinyl alcohol-type film and a polyurethane film from a polyurethane film roll and a polyvinyl alcohol-type film roll, and makes a film laminated body Forming a film, and stretching the film laminate at a temperature of 45 ° C. to 55 ° C .; And separating the thermoplastic polyurethane film and the polyvinyl alcohol-based film.
한편, 상기 폴리우레탄 필름과 폴리비닐알코올계 필름은 부착된 후, 롤 형상으로 재권취된 다음, 재권취된 필름 적층체 롤로부터 필름 적층체를 권출하여 연신 공정에 투입될 수도 있고, 또는 재권취 없이 바로 연신 공정에 투입될 수 있다.Meanwhile, after the polyurethane film and the polyvinyl alcohol-based film are attached, they may be rewound in a roll shape, and then the film laminate may be unwound from the rewound film laminate roll and introduced into the stretching process, or may be rewound. It can be added directly to the drawing process without.
또한, 상기 분리 단계는 폴리우레탄 필름과 폴리비닐알코올계 필름 사이에 박리 수단(예를 들면, 박리 롤)을 삽입하여, 폴리우레탄 필름과 폴리비닐알코올계 필름의 계면을 분리시킨 다음, 분리된 폴리우레탄 필름과 폴리비닐알코올계 필름을 서로 다른 롤에 권취하는 방법으로 수행될 수 있다. In addition, in the separating step, a peeling means (eg, a peeling roll) is inserted between the polyurethane film and the polyvinyl alcohol-based film to separate the interface between the polyurethane film and the polyvinyl alcohol-based film, and then the separated poly The urethane film and the polyvinyl alcohol-based film may be carried out by a method of winding up different rolls.
상기와 같은 방법에 의해 제조된 본 발명의 편광자는 그 두께가 10㎛ 이하, 예를 들면, 1㎛ 내지 10㎛, 3㎛ 내지 10㎛ 또는 1㎛ 내지 5㎛ 정도로 매우 얇다. 또한, 이와 같이 얇은 두께에서도, 단체 투과도가 40 ~ 45% 정도이며, 편광도가 99.0% 이상, 바람직하게는 99.5% 이상, 더 바람직하게는 99.7% 이상으로 매우 우수한 광학 물성을 나타낸다.The polarizer of the present invention produced by the method as described above is very thin, about 10 μm or less, for example, 1 μm to 10 μm, 3 μm to 10 μm, or 1 μm to 5 μm. In addition, even at such a thin thickness, the unitary transmittance is about 40 to 45%, and the polarization degree is 99.0% or more, preferably 99.5% or more, and more preferably 99.7% or more.
또한, 본 발명의 편광자는 폭 방향에 대한 편광도 균일성이 매우 우수하다. 구체적으로는, 본 발명의 편광자는, 편광자의 폭 방향을 따라 등간격으로 위치하는 10개의 점에서 측정된 편광도의 표준 편차가 0.002% 이하이다. 이와 같이 본 발명의 편광자의 폭 방향 편광도 균일성이 우수한 것은 기재 필름으로 사용되는 폴리우레탄 필름의 열 수축 특성이 폴리비닐알코올계 필름과 유사하여 폴리비닐알코올계 필름의 폭 방향 전 영역에 걸쳐 연신이 균일하게 이루어질 수 있기 때문인 것으로 판단된다.Moreover, the polarizer of this invention is very excellent in the uniformity of the polarization degree to the width direction. Specifically, the polarizer of the present invention has a standard deviation of the degree of polarization measured at ten points located at equal intervals along the width direction of the polarizer at 0.002% or less. Thus, the uniformity in the polarization degree of the polarizer of the present invention is excellent in the uniformity in the heat shrinkage characteristics of the polyurethane film used as the base film is similar to the polyvinyl alcohol-based film is stretched over the entire width-direction region of the polyvinyl alcohol-based film This is because it can be made uniform.
한편, 상기와 같은 본 발명의 편광자에 일면 또는 양면에 투명 필름을 적층하여 편광판을 형성할 수 있다. 이때 상기 투명 필름으로는, 당해 기술 분야에서 편광자 보호 필름 또는 위상차 필름으로 사용되는 다양한 필름들이 제한 없이 사용될 수 있으며, 예를 들면, 셀룰로오스계 필름, 아크릴계 필름, 사이클로올레핀계 필름 등이 사용될 수 있다.On the other hand, a polarizing plate can be formed by laminating a transparent film on one side or both sides on the polarizer of the present invention as described above. In this case, as the transparent film, various films used as a polarizer protective film or a retardation film in the art may be used without limitation. For example, a cellulose film, an acrylic film, a cycloolefin film, or the like may be used.
편광자와 투명 필름의 적층은 특별히 제한되지 않으며, 당해 기술 분야에 잘 알려진 접착제 또는 점착제 등을 이용하여 수행될 수 있다. 이때 상기 점착제 또는 접착제는 사용되는 투명 필름의 재질 등을 고려하여 적절하게 선택될 수 있으며, 예를 들면, 투명 필름으로 TAC을 사용하는 경우에는 폴리비닐알코올계 접착제와 같은 수계 접착제를 이용할 수 있고, 투명 필름으로 아크릴 필름이나 COP 필름 등을 사용하는 경우에는 아크릴계 접착제, 에폭시계 접착제와 같은 광 경화 또는 열경화성 접착제를 이용할 수 있다.Lamination of the polarizer and the transparent film is not particularly limited, and may be performed using an adhesive or an adhesive well known in the art. At this time, the pressure-sensitive adhesive or adhesive may be appropriately selected in consideration of the material of the transparent film to be used, for example, when using a TAC as a transparent film, an aqueous adhesive such as a polyvinyl alcohol-based adhesive may be used, When using an acrylic film, a COP film, etc. as a transparent film, photocuring or thermosetting adhesives, such as an acrylic adhesive and an epoxy adhesive, can be used.
한편, 상기 편광자와 투명 필름의 적층 방식은, 특별히 제한되는 것은 아니나, 생산성 측면에서 편광자 필름 롤과 투명 필름 롤을 이용한 롤-투-롤 방식으로 이루어지는 것이 바람직하다. 롤-투-롤 방식으로 편광자와 투명 필름을 적층하여 편광판을 제조하는 방법은 당해 기술 분야에 잘 알려져 있으므로, 구체적인 설명은 생략한다. 이와 같이 롤-투-롤 방식으로 편광판을 제조할 경우, 장척의 롤형 편광판을 얻을 수 있다. On the other hand, the lamination method of the polarizer and the transparent film is not particularly limited, but is preferably made of a roll-to-roll method using a polarizer film roll and a transparent film roll in terms of productivity. Since a method of manufacturing a polarizing plate by laminating a polarizer and a transparent film in a roll-to-roll manner is well known in the art, a detailed description thereof will be omitted. Thus, when manufacturing a polarizing plate by a roll-to-roll system, a long rolled polarizing plate can be obtained.
한편, 상기 본 발명의 편광판은, 투명 필름 이외에 휘도향상필름, 프라이머층, 하드코팅층, 방현층, 반사 방지층 또는 액정 패널과의 부착을 위한 점착층 등과 같은 다른 기능성 광학층을 추가로 포함할 수 있다. 이들 광학층은 형성 방법은 특별히 한정되지 않으며, 당해 기술 분야에 잘 알려진 공지의 방법을 이용할 수 있다. On the other hand, the polarizing plate of the present invention, in addition to the transparent film may further include another functional optical layer, such as a brightness enhancement film, a primer layer, a hard coating layer, an antiglare layer, an antireflection layer or an adhesive layer for adhesion with a liquid crystal panel. . The formation method of these optical layers is not specifically limited, The well-known method well known in the art can be used.
본 발명의 편광판은 종래의 편광판에 비해 그 두께가 매우 얇으면서도 우수한 광학 특성을 가져, 액정표시패널, 유기전계발광장치 등과 같은 디스플레이 장치에 유용하게 사용될 수 있다. The polarizing plate of the present invention has a very thin thickness compared to the conventional polarizing plate and has excellent optical properties, and thus may be usefully used in display devices such as liquid crystal display panels and organic light emitting display devices.
이하, 구체적인 실시예를 통해 본 발명을 보다 구체적으로 설명한다.Hereinafter, the present invention will be described in more detail with reference to specific examples.
실시예 1Example 1
두께 60㎛의 폴리우레탄 필름 양면에 30㎛ 두께의 폴리비닐알코올 필름을 부착하여 필름 적층체를 제조하였다. 그런 다음, 상기 필름 적층체를 25℃ 순수 용액에서 15초간 팽윤(swelling)시킨 후, 0.3wt% 농도 및 25℃의 요오드 용액에서 60초간 염착 공정을 진행하였다. 그런 다음, 상기 필름 적층체를 붕산 1wt% 용액에서 15초간 세정한 후, 45℃의 붕산 2wt% 용액에서 7배 연신 공정을 진행하였다. 연신 이후 5wt%의 KI 용액에서 보색 공정을 거친 후, 80℃ 오븐에서 5분간 건조 공정을 진행하였다. 그런 다음, 폴리우레탄 필름과 폴리비닐알코올 필름을 분리하여, 최종적으로 두께 7.5㎛의 박형 편광자를 제조하였다. A 30-micrometer-thick polyvinyl alcohol film was attached to both sides of a 60-micrometer-thick polyurethane film to prepare a film laminate. Then, the film laminate was swelled for 15 seconds in a 25 ° C. pure solution, followed by a dyeing process for 60 seconds in a 0.3 wt% concentration and an iodine solution at 25 ° C. Then, the film laminate was washed for 15 seconds in a 1 wt% solution of boric acid, and then stretched 7 times in a 2 wt% solution of boric acid at 45 ° C. After stretching, after the complementary color process in a 5 wt% KI solution, the drying process was performed for 5 minutes in an 80 ℃ oven. Then, the polyurethane film and the polyvinyl alcohol film were separated to finally produce a thin polarizer having a thickness of 7.5 μm.
실시예 2Example 2
연신 공정을 50℃의 붕산 2wt% 용액에서 수행한 점을 제외하고는, 실시예 1과 동일한 방법으로 박형 편광자를 제조하였다.A thin polarizer was prepared in the same manner as in Example 1 except that the stretching process was performed in a 2 wt% solution of boric acid at 50 ° C.
실시예 3Example 3
연신 공정을 55℃의 붕산 2wt% 용액에서 수행한 점을 제외하고는, 실시예 1과 동일한 방법으로 박형 편광자를 제조하였다.A thin polarizer was prepared in the same manner as in Example 1 except that the stretching process was performed in a 2 wt% solution of boric acid at 55 ° C.
실험예 1 Experimental Example 1
상기 실시예 1 ~ 3에 의해 제조된 박형 편광자의 단체 투과도, 편광도 및 단체 색상, 직교 색상 등의 광학 물성을 JASCO V-7100 Spectrophotometer로 측정하였다. 측정 결과는 [표 1]에 나타내었다.Optical properties such as the single transmittance, polarization degree, single color, and orthogonal color of the thin polarizers prepared in Examples 1 to 3 were measured with a JASCO V-7100 Spectrophotometer. The measurement results are shown in [Table 1].
표 1
구분 연신온도 단체 투과도(Ts, %) 편광도(DOP, %) 단체 색상 직교 색상
a b a b
실시예 1 45℃ 42.10 99.6714 -0.13 1.10 2.14 -4.51
실시예 2 50℃ 42.09 99.9226 -0.27 1.73 1.41 -2.65
실시예 3 55℃ 42.01 99.9219 -0.37 1.63 1.37 -2.83
Table 1
division Drawing temperature Single transmittance (Ts,%) Polarization degree (DOP,%) Group colors Orthogonal colors
a b a b
Example 1 45 ℃ 42.10 99.6714 -0.13 1.10 2.14 -4.51
Example 2 50 ℃ 42.09 99.9226 -0.27 1.73 1.41 -2.65
Example 3 55 ℃ 42.01 99.9219 -0.37 1.63 1.37 -2.83
상기 [표 1]에 도시된 바와 같이, 기재 필름으로 폴리우레탄 필름을 사용할 경우, 편광도가 99.5% 이상으로 광학 특성이 우수하며, 이 중에서도, 연신 온도가 50℃ ~ 55℃인 경우에는 편광도가 99.9% 이상으로 광학 특성이 특히 우수함을 알 수 있다. As shown in Table 1, when the polyurethane film is used as the base film, the polarization degree is 99.5% or more, and the optical properties are excellent. Among these, when the stretching temperature is 50 ° C to 55 ° C, the polarization degree is 99.9. It can be seen that the optical properties are particularly excellent at more than%.
실시예 4Example 4
두께 60㎛의 폴리우레탄 필름 양면에 30㎛ 두께의 폴리비닐알코올 필름을 부착하여 필름 적층체를 제조하였다. 그런 다음, 상기 필름 적층체를 25℃ 순수 용액에서 15초간 팽윤(swelling)시킨 후, 0.27wt% 농도 및 25℃의 요오드 용액에서 60초간 염착 공정을 진행하였다. 그런 다음, 상기 필름 적층체를 붕산 1wt% 용액에서 15초간 세정한 후, 50℃의 붕산 2wt% 용액에서 7배 연신 공정을 진행하였다. 연신 이후 5wt%의 KI 용액에서 보색 공정을 거친 후, 80℃ 오븐에서 5분간 건조 공정을 진행하였다. 그런 다음, 폴리우레탄 필름과 폴리비닐알코올 필름을 분리하여, 최종적으로 두께 7.5㎛의 박형 편광자를 제조하였다. A 30-micrometer-thick polyvinyl alcohol film was attached to both sides of a 60-micrometer-thick polyurethane film to prepare a film laminate. Then, the film laminate was swelled for 15 seconds in a 25 ° C. pure solution, followed by a dyeing process for 60 seconds in a 0.27 wt% concentration and an iodine solution at 25 ° C. Then, the film laminate was washed for 15 seconds in a 1 wt% solution of boric acid, and then stretched 7 times in a 2 wt% solution of boric acid at 50 ° C. After stretching, after the complementary color process in a 5 wt% KI solution, the drying process was performed for 5 minutes in an 80 ℃ oven. Then, the polyurethane film and the polyvinyl alcohol film were separated to finally produce a thin polarizer having a thickness of 7.5 μm.
실시예 5Example 5
연신 공정을 붕산 2.5wt% 용액에서 수행한 점을 제외하고는, 실시예 4와 동일한 방법으로 박형 편광자를 제조하였다.A thin polarizer was prepared in the same manner as in Example 4, except that the stretching process was performed in a 2.5 wt% solution of boric acid.
실시예 6Example 6
연신 공정을 붕산 3.5wt% 용액에서 수행한 점을 제외하고는, 실시예 4와 동일한 방법으로 박형 편광자를 제조하였다.A thin polarizer was prepared in the same manner as in Example 4 except that the stretching process was performed in a 3.5 wt% solution of boric acid.
실험예 2 Experimental Example 2
상기 실시예 4 ~ 6에 의해 제조된 박형 편광자의 단체 투과도, 편광도 및 단체 색상, 직교 색상 등의 광학 물성을 JASCO V-7100 Spectrophotometer로 측정하였다. 측정 결과는 [표 2]에 나타내었다.Optical properties such as the single transmittance, polarization degree, single color, and orthogonal color of the thin polarizers prepared in Examples 4 to 6 were measured with a JASCO V-7100 Spectrophotometer. The measurement results are shown in [Table 2].
표 2
구분 단체 투과도(Ts, %) 편광도(DOP, %) 단체 색상 직교 색상
a b a b
실시예 4 43.02 99.6269 -0.15 1.52 1.90 -2.00
실시예 5 43.20 99.5939 -0.25 1.69 1.26 -2.70
실시예 6 43.01 99.2278 -0.14 1.75 1.55 -1.04
TABLE 2
division Single transmittance (Ts,%) Polarization degree (DOP,%) Group colors Orthogonal colors
a b a b
Example 4 43.02 99.6269 -0.15 1.52 1.90 -2.00
Example 5 43.20 99.5939 -0.25 1.69 1.26 -2.70
Example 6 43.01 99.2278 -0.14 1.75 1.55 -1.04
상기 [표 2]를 통해, 폴리우레탄 기재 필름을 사용할 경우, 붕산 농도가 3.5중량% 수준일 경우, 붕산 농도가 각각 2.0중량%, 2.5중량%인 실시예 4 및 5에 비해 편광도가 상대적으로 저하됨을 알 수 있다.When using the polyurethane-based film through [Table 2], when the boric acid concentration is 3.5% by weight level, the polarization degree is relatively reduced compared to Examples 4 and 5 that the boric acid concentration is 2.0% by weight, 2.5% by weight, respectively. It can be seen.
실시예 7Example 7
두께 60㎛의 폴리우레탄 필름 양면에 30㎛ 두께의 폴리비닐알코올 필름을 부착하여 필름 적층체를 제조하였다. 그런 다음, 상기 필름 적층체를 25℃ 순수 용액에서 15초간 팽윤(swelling)시킨 후, 0.29wt% 농도 및 25℃의 요오드 용액에서 60초간 염착 공정을 진행하였다. 그런 다음, 상기 필름 적층체를 붕산 1wt% 용액에서 15초간 세정한 후, 50℃의 붕산 2wt% 용액에서 6.5배 연신 공정을 진행하였다. 연신 이후 5wt%의 KI 용액에서 보색 공정을 거친 후, 80℃ 오븐에서 5분간 건조 공정을 진행하였다. 그런 다음, 폴리우레탄 필름과 폴리비닐알코올 필름을 분리하여, 최종적으로 두께 7.5㎛의 박형 편광자를 제조하였다. A 30-micrometer-thick polyvinyl alcohol film was attached to both sides of a 60-micrometer-thick polyurethane film to prepare a film laminate. Then, the film laminate was swelled for 15 seconds in a 25 ° C. pure solution, followed by a dyeing process for 60 seconds in a 0.29 wt% concentration and an iodine solution at 25 ° C. Then, the film laminate was washed in a 1 wt% solution of boric acid for 15 seconds, and then a 6.5-fold stretching process was performed in a 2 wt% solution of boric acid at 50 ° C. After stretching, after the complementary color process in a 5 wt% KI solution, the drying process was performed for 5 minutes in an 80 ℃ oven. Then, the polyurethane film and the polyvinyl alcohol film were separated to finally produce a thin polarizer having a thickness of 7.5 μm.
실시예 8Example 8
연신 배율을 7배로 한 점을 제외하고는, 실시예 7과 동일한 방법으로 박형 편광자를 제조하였다.A thin polarizer was produced in the same manner as in Example 7, except that the draw ratio was increased to 7 times.
실시예 9Example 9
연신 배율을 7.5배로 한 점을 제외하고는, 실시예 7과 동일한 방법으로 박형 편광자를 제조하였다.A thin polarizer was produced in the same manner as in Example 7 except that the draw ratio was 7.5 times.
실험예 3Experimental Example 3
상기 실시예 7 ~ 9에 의해 제조된 박형 편광자의 단체 투과도 및 편광도를 JASCO V-7100 Spectrophotometer로 측정하였다. 측정 결과는 [표 3]에 나타내었다.Single transmittance and polarization degree of the thin polarizers prepared in Examples 7 to 9 were measured with a JASCO V-7100 Spectrophotometer. The measurement results are shown in [Table 3].
표 3
구분 단체투과도(Ts, %) 편광도(DOP, %)
실시예 7 42.37 99.7593
실시예 8 42.35 99.9086
실시예 9 41.60 99.8564
TABLE 3
division Group Permeability (Ts,%) Polarization degree (DOP,%)
Example 7 42.37 99.7593
Example 8 42.35 99.9086
Example 9 41.60 99.8564
비교예 1Comparative Example 1
두께 60㎛의 폴리우레탄 필름 대신 두께 90㎛의 폴리에틸렌 필름을 사용한 점을 제외하고는 실시예 5와 동일한 방법으로 박형 편광자를 제조하였다. A thin polarizer was prepared in the same manner as in Example 5 except that a polyethylene film having a thickness of 90 μm was used instead of a polyurethane film having a thickness of 60 μm.
비교예 2Comparative Example 2
두께 60㎛의 폴리우레탄 필름 대신 두께 50㎛의 폴리프로필렌 필름을 사용한 점을 제외하고는 실시예 8과 동일한 방법으로 박형 편광자를 제조하였다. A thin polarizer was prepared in the same manner as in Example 8 except that a polypropylene film having a thickness of 50 μm was used instead of a polyurethane film having a thickness of 60 μm.
비교예 3Comparative Example 3
두께 60㎛의 폴리우레탄 필름 대신 두께 40㎛의 폴리에틸렌테레프탈레이트 필름을 사용한 점을 제외하고는 실시예 8과 동일한 방법으로 박형 편광자를 제조하고자 하였으나, 연신 도중 파단이 발생하여 박형 편광자 제조가 불가능하였다. 도 2에는 본 비교예 3의 연신 과정에서의 필름 적층체의 상태를 보여주는 사진이 도시되어 있다. A thin polarizer was prepared in the same manner as in Example 8 except that a polyethylene terephthalate film having a thickness of 40 μm was used instead of a polyurethane film having a thickness of 60 μm, but breakage occurred during stretching, and thus, the thin polarizer could not be manufactured. Figure 2 is a photograph showing the state of the film laminate in the stretching process of the present Comparative Example 3.
비교예 4Comparative Example 4
연신 공정을 40℃의 붕산 2wt% 용액에서 수행한 점을 제외하고는, 실시예 1과 동일한 방법으로 박형 편광자를 제조하였다.A thin polarizer was prepared in the same manner as in Example 1 except that the stretching process was performed in a 40 wt% solution of boric acid at 2 wt%.
비교예 5Comparative Example 5
연신 공정을 60℃의 붕산 2wt% 용액에서 수행한 점을 제외하고는, 실시예 1과 동일한 방법으로 박형 편광자를 제조하였다.A thin polarizer was prepared in the same manner as in Example 1, except that the stretching process was performed in a 2 wt% solution of boric acid at 60 ° C.
실험예 4 : 광학 물성 측정Experimental Example 4 Measurement of Optical Properties
상기 비교예 1 ~ 3, 4 및 5에 의해 제조된 박형 편광자의 단체 투과도, 편광도 및 단체 색상, 직교 색상 등의 광학 물성을 JASCO V-7100 Spectrophotometer로 측정하였다. 측정 결과는 [표 4]에 나타내었다.Optical properties such as single transmittance, polarization degree, single color, and orthogonal color of the thin polarizers prepared by Comparative Examples 1 to 3, 4, and 5 were measured by a JASCO V-7100 Spectrophotometer. The measurement results are shown in [Table 4].
표 4
구분 단체 투과도(Ts, %) 편광도(DOP, %) 단체 색상 직교 색상
a b a b
비교예 1 43.29 93.0947 1.35 0.62 5.93 -1.90
비교예 2 42.56 98.7137 0.25 1.12 2.97 -2.68
비교예 4 41.91 98.5201 -0.39 1.58 1.32 -2.91
비교예 5 42.32 98.4843 -0.06 0.84 2.14 -4.02
Table 4
division Single transmittance (Ts,%) Polarization degree (DOP,%) Group colors Orthogonal colors
a b a b
Comparative Example 1 43.29 93.0947 1.35 0.62 5.93 -1.90
Comparative Example 2 42.56 98.7137 0.25 1.12 2.97 -2.68
Comparative Example 4 41.91 98.5201 -0.39 1.58 1.32 -2.91
Comparative Example 5 42.32 98.4843 -0.06 0.84 2.14 -4.02
상기 [표 1]~[표 4]를 통해, 기재 필름으로 폴리우레탄 필름을 사용한 실시예 1 ~ 9에 의해 제조된 편광자의 경우, 단체 투과도, 편광도, 색감 등의 광학 물성이 다른 종류의 기재 필름을 사용한 비교예 1 및 2에 의해 제조된 편광자에 비해 매우 우수한 것을 알 수 있다. In the case of the polarizer manufactured by Examples 1-9 which used the polyurethane film as a base film through the said [Table 1]-[Table 4], the kind of base material from which optical properties, such as a single transmittance, polarization degree, a color sense, differs It turns out that it is very excellent compared with the polarizer manufactured by Comparative Examples 1 and 2 using a film.
실험예 5 : 편광도 균일성 평가Experimental Example 5 Evaluation of Polarization Uniformity
상기 실시예 2 및 비교예 1에 의해 제조된 편광자들 각각에 대해, 편광자의 폭 방향을 따라 등간격으로 위치하는 10개의 점에서 편광도를 측정한 후, 측정된 편광도의 표준편차 값을 계산하였다. 측정 결과는 하기 [표 5]에 나타내었다.For each of the polarizers prepared by Example 2 and Comparative Example 1, the polarization degree was measured at ten points positioned at equal intervals along the width direction of the polarizer, and then the standard deviation value of the measured polarization degree was calculated. The measurement results are shown in the following [Table 5].
표 5
위치 편광도(%)
실시예 2 비교예 1
1 99.9238 93.1204
2 99.9206 93.0546
3 99.9211 93.0746
4 99.9228 93.1045
5 99.9244 93.1605
6 99.9241 93.1732
7 99.9227 93.0846
8 99.9219 93.0582
9 99.9207 93.0284
10 99.9235 92.0875
평균 99.9226 93.0947
표준편차 0.0014 0.0461
Table 5
location % Polarization
Example 2 Comparative Example 1
One 99.9238 93.1204
2 99.9206 93.0546
3 99.9211 93.0746
4 99.9228 93.1045
5 99.9244 93.1605
6 99.9241 93.1732
7 99.9227 93.0846
8 99.9219 93.0582
9 99.9207 93.0284
10 99.9235 92.0875
Average 99.9226 93.0947
Standard Deviation 0.0014 0.0461
[부호의 설명][Description of the code]
H: 홀더H: Holder
A: 폴리비닐알코올계 필름A: polyvinyl alcohol film
B: 고분자 필름B: polymer film
MD: 종연신 방향MD: Longitudinal stretching direction

Claims (16)

  1. 열가소성 폴리우레탄 필름의 적어도 일면에 인력 또는 접착제를 이용하여 미연신 폴리비닐알코올계 필름을 부착하여 필름 적층체를 형성하는 단계; Attaching an unstretched polyvinyl alcohol-based film to at least one surface of the thermoplastic polyurethane film by using attraction force or an adhesive to form a film laminate;
    상기 필름 적층체를 45℃ 내지 55℃의 온도에서 연신하는 단계; 및Stretching the film laminate at a temperature of 45 ° C. to 55 ° C .; And
    상기 열가소성 폴리우레탄 필름과 폴리비닐알코올계 필름을 분리하는 단계를 포함하는 박형 편광자의 제조 방법.Method of manufacturing a thin polarizer comprising the step of separating the thermoplastic polyurethane film and the polyvinyl alcohol-based film.
  2. 제1항에 있어서,The method of claim 1,
    상기 연신하는 단계는 50℃ 내지 55℃의 온도에서 수행되는 것인 박형 편광자의 제조 방법.The stretching step is a method of producing a thin polarizer is carried out at a temperature of 50 ℃ to 55 ℃.
  3. 제1항에 있어서,The method of claim 1,
    상기 연신하는 단계는 5배 내지 15배의 연신 배율로 수행되는 것인 박형 편광자의 제조 방법. The stretching step is a method of manufacturing a thin polarizer is performed at a draw ratio of 5 to 15 times.
  4. 제1항에 있어서,The method of claim 1,
    상기 미연신 폴리비닐알코올계 필름은 두께가 10㎛ 내지 60㎛인 박형 편광자의 제조 방법.The unstretched polyvinyl alcohol-based film has a thickness of 10 ㎛ to 60 ㎛ manufacturing method of a thin polarizer.
  5. 제1항에 있어서,The method of claim 1,
    상기 연신하는 단계는 붕산 농도가 1 내지 5%인 붕산 수용액에서 수행되는 것인 박형 편광자의 제조 방법.The stretching step is a method of producing a thin polarizer is carried out in an aqueous boric acid solution having a boric acid concentration of 1 to 5%.
  6. 제1항에 있어서, The method of claim 1,
    상기 연신하는 단계는 붕산 농도가 1 내지 3%인 붕산 수용액에서 수행되는 것인 박형 편광자의 제조 방법.The stretching step is a method of manufacturing a thin polarizer is carried out in an aqueous boric acid solution having a boric acid concentration of 1 to 3%.
  7. 제1항에 있어서,The method of claim 1,
    상기 연신하는 단계는 폴리비닐알코올계 필름의 두께가 10㎛ 이하가 되도록 수행되는 것인 박형 편광자의 제조 방법.The stretching step is a method of manufacturing a thin polarizer is performed so that the thickness of the polyvinyl alcohol-based film is 10㎛ or less.
  8. 제1항에 있어서,The method of claim 1,
    상기 연신하는 단계는 폴리비닐알코올계 필름의 폭 수축율이 30% ~ 80%이 되도록 수행되는 것인 박형 편광자의 제조 방법.The stretching step is a method of manufacturing a thin polarizer is performed so that the width shrinkage of the polyvinyl alcohol-based film is 30% to 80%.
  9. 제1항에 있어서,The method of claim 1,
    상기 연신하는 단계 이후에 연신된 폴리비닐알코올계 필름과 연신된 고분자 필름 사이의 부착력이 2N/2cm 이하인 박형 편광자의 제조 방법.After the stretching step, the adhesive force between the stretched polyvinyl alcohol-based film and the stretched polymer film is 2N / 2cm or less manufacturing method of a thin polarizer.
  10. 제1항에 있어서,The method of claim 1,
    상기 열가소성 폴리우레탄 필름과 폴리비닐알코올계 필름을 분리하는 단계는 2N/2cm 이하의 박리력을 가하여 수행되는 것인 박형 편광자의 제조 방법.Separating the thermoplastic polyurethane film and the polyvinyl alcohol-based film is a method of manufacturing a thin polarizer is performed by applying a peel force of 2N / 2cm or less.
  11. 제1항에 있어서,The method of claim 1,
    상기 연신하는 단계 전에 상기 필름 적층체에 요오드 및 이색성 염료 중 적어도 하나를 염착시키는 단계를 더 포함하는 박형 편광자의 제조 방법.And dyeing at least one of iodine and a dichroic dye onto the film laminate before the stretching step.
  12. 제1항에 있어서,The method of claim 1,
    상기 연신하는 단계 이후에 연신된 필름 적층체를 건조하는 단계를 더 포함하는 박형 편광자의 제조 방법.And drying the stretched film laminate after the stretching step.
  13. 두께가 10㎛ 이하이고,Thickness is 10 μm or less,
    단체 투과도가 40% 내지 43%이며,Singlet transmittance is 40% to 43%,
    편광도가 99.0% 이상이고,The degree of polarization is 99.0% or more,
    편광자의 폭 방향을 따라 등간격으로 위치하는 10개의 점에서 측정된 편광도의 표준편차가 0.002% 이하인 박형 편광자.A thin polarizer in which the standard deviation of the degree of polarization measured at ten points at equal intervals along the width direction of the polarizer is 0.002% or less.
  14. 제13항에 있어서,The method of claim 13,
    상기 편광도가 99.5% 이상인 박형 편광자.Thin polarizer whose said degree of polarization is 99.5% or more.
  15. 청구항 13의 박형 편광자를 포함하는 편광판.A polarizing plate comprising the thin polarizer of claim 13.
  16. 청구항 15의 편광판을 포함하는 디스플레이 장치.Display device including the polarizing plate of claim 15.
PCT/KR2014/005184 2013-06-18 2014-06-12 Thin polarizer with excellent optical properties, method for manufacturing same, and polarizing plate and display device comprising thin polarizer WO2014204132A1 (en)

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KR102415828B1 (en) * 2019-09-30 2022-06-30 코오롱인더스트리 주식회사 Polyester multilayer-film and methof for preparing thereof

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