Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
  • H10K59/80—Constructional details
  • H10K59/8791—Arrangements for improving contrast, e.g. preventing reflection of ambient light
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/02—Physical, chemical or physicochemical properties
  • B32B7/023—Optical properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
  • B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
• • 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
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/12—Chemical modification
  • C08J7/126—Halogenation
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/30—Polarising elements
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/30—Polarising elements
  • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
  • G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
• • 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
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B33/00—Electroluminescent light sources
  • H05B33/02—Details
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
  • H10K59/50—OLEDs integrated with light modulating elements, e.g. with electrochromic elements, photochromic elements or liquid crystal elements

Definitions

• the present invention relates to a polarizing film, a polarizing film, a laminated polarizing film, an image display panel, an image display device, and a method for manufacturing a polarizing film.
• a polarizing film used for various image display devices such as liquid crystal display devices and organic EL display devices
• dyed such as iodine and dichroic dyes
• Polyvinyl alcohol-based films (containing dichroic substances) have been used.
• the polarizing film is produced by subjecting a polyvinyl alcohol-based film to various treatments such as swelling, dyeing, crosslinking and stretching in a bath, followed by washing treatment and drying.
• the polarizing film is usually used as a polarizing film (polarizing plate) in which a protective film such as triacetyl cellulose is attached to one surface or both surfaces thereof with an adhesive.
• the polarizing film is used as a laminated polarizing film (optical laminated body) by laminating other optical layers as necessary, and the polarizing film or the laminated polarizing film (optical laminated body) is a liquid crystal cell or an organic EL element. And the like, and the front side transparent member (window layer) on the viewing side and the front side transparent member such as a touch panel, which are bonded together via an adhesive layer or an adhesive layer to provide the above various image display devices. Used.
• a dye-based polarizing film using a dichroic dye such as an azo-based compound generally has a higher temperature and a higher temperature than an iodine-based polarizing film (a polarizing film formed by adsorbing and orienting iodine on a polyvinyl alcohol-based film). It is known that light resistance under high humidity conditions is excellent (Patent Document 2), and in order to improve color loss in a light resistance test of a polarizing plate having the dye-based polarizing film, the polarizing plate is used. It is disclosed that the hindered amine compound is contained in the adhesive used (Patent Document 3).
• the polarizing film is colored and the single transmittance thereof is lowered.
• the present invention is a polarizing film, a laminated polarizing film, an image display panel, an image display device, and a method for producing the polarizing film, which use a polarizing film having an excellent effect of suppressing a decrease in the single transmittance due to the coloring of the polarizing film.
• the purpose is to provide.
• the present invention relates to a polarizing film formed by adsorbing and orienting iodine on a polyvinyl alcohol-based film, the polarizing film including a compound having a nitroxy radical or a nitroxide group.
• the present invention also relates to a polarizing film having a transparent protective film attached to at least one surface of the polarizing film.
• the present invention also relates to a laminated polarizing film in which the polarizing film is attached to an optical layer.
• the present invention also relates to an image display panel in which the polarizing film or the laminated polarizing film is attached to an image display cell.
• the present invention also relates to an image display device comprising a front transparent member on the polarizing film or laminated polarizing film side of the image display panel.
• the present invention is the method for producing a polarizing film, which is obtained by subjecting a polyvinyl alcohol-based film to an optional swelling step and a washing step, and at least a dyeing step, a crosslinking step, and a stretching step.
• a method for producing a polarizing film, wherein the treatment bath in one or more treatment steps of the step, the washing step, the dyeing step, the crosslinking step, and the stretching step contains a nitroxy radical or a compound having a nitroxide group. .
• the present invention is the method for producing a polarizing film, wherein a polyvinyl alcohol-based resin layer containing a polyvinyl alcohol-based resin is formed on one side of a long thermoplastic resin substrate to prepare a laminate. And, while conveying the obtained laminate in the longitudinal direction, to the laminate, an insolubilization treatment step, a crosslinking treatment step, and a washing treatment step, and at least an in-air auxiliary stretching treatment step, a dyeing treatment step, and underwater. Obtained by performing a stretching treatment step, the treatment bath in any one or more of the insolubilization treatment step, the crosslinking treatment step, the washing treatment step, the dyeing treatment step, and the underwater stretching treatment step is nitro.
• the present invention relates to a method for producing a polarizing film containing a compound having a xy radical or a nitroxide group.
• the polarizing film of the present invention is an iodine-based polarizing film formed by adsorbing and orienting iodine on a polyvinyl alcohol-based film, and contains a compound having a nitroxy radical or a nitroxide group.
• the iodine-based polarizing film is inferior in durability such as heat resistance to the dye-based polarizing film, and the reason is included in the polarizing film. It is presumed that the iodine generated promotes the deterioration phenomenon called polyene formation that occurs in the dehydration reaction of polyvinyl alcohol in a high temperature environment.
• a compound having a nitroxy radical or a nitroxide group is presumed to be capable of efficiently trapping a radical generated in the above polyene reaction under a high temperature environment. It is possible to suppress a decrease in single-body transmittance due to.
• the polarizing film of the present invention contains a compound formed by adsorption alignment of iodine on a polyvinyl alcohol film and having a nitroxy radical or a nitroxide group.
• the polyvinyl alcohol (PVA) film a film having a light-transmitting property in a visible light region and capable of dispersing and adsorbing iodine can be used without particular limitation.
• the PVA-based film which is usually used as a raw fabric, preferably has a thickness of about 1 to 100 ⁇ m, more preferably about 1 to 50 ⁇ m, and a width of about 100 to 5000 mm.
• polyvinyl alcohol or its derivative can be mentioned.
• the polyvinyl alcohol derivative include polyvinyl formal, polyvinyl acetal, olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and their modified alkyl esters, acrylamides, and the like. Is mentioned.
• the polyvinyl alcohol preferably has an average degree of polymerization of about 100 to 10,000, more preferably about 1,000 to 10,000, and even more preferably about 1,500 to 4,500. ..
• the saponification degree of the polyvinyl alcohol is preferably about 80 to 100 mol%, more preferably about 95 mol% to 99.95 mol.
• the average degree of polymerization and the degree of saponification can be determined according to JIS K 6726.
• the polyvinyl alcohol film may contain additives such as a plasticizer and a surfactant.
• the plasticizer include polyols such as glycerin, diglycerin, triglycerin, ethylene glycol, propylene glycol, and polyethylene glycol, and condensates thereof.
• the amount of the additive used is not particularly limited, but is preferably about 20% by weight or less in the polyvinyl alcohol film.
• the content of iodine in the polarizing film is preferably 1% by weight or more and 15% by weight or less.
• the content of the iodine in the polarizing film is preferably 1.5% by weight or more, more preferably 2% by weight or more, from the viewpoint of suppressing color loss during a durability test, and From the viewpoint of preventing polyene formation, it is preferably 12% by weight or less, and more preferably 10% by weight or less.
• the polarizing film contains a compound having a nitroxy radical or a nitroxide group.
• the compounds having a nitroxy radical or a nitroxide group may be used alone or in combination of two or more kinds.
• N-oxyl compound functional group, the C-N (-C) -O ⁇ compounds having (O ⁇ is an oxy radical)
• known materials can be used.
• N-oxyl compound include compounds having an organic group having the following structure.
• R 1 represents an oxy radical
• R 2 to R 5 independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms
• n represents 0 or 1.
• the left side of the dotted line portion represents an arbitrary organic group.
• Examples of the compound having an organic group include compounds represented by the following general formulas (2) to (5).
• R 1 to R 5 and n are the same as above, and R 6 represents a hydrogen atom, or an alkyl group, an acyl group, or an aryl group having 1 to 10 carbon atoms.
• N represents 0 or 1.
• R 1 to R 5 and n are the same as above, and R 7 and R 8 are independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, Represents an acyl group or an aryl group.
• R 9 to R 11 are independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, Represents an acyl group, an amino group, an alkoxy group, a hydroxy group, or an aryl group.
• R 1 to R 5 and n are the same as above, and R 12 is a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms, an amino group, an alkoxy group, a hydroxy group. Represents a group or an aryl group.
• R 2 to R 5 are preferably an alkyl group having 1 to 6 carbon atoms, and having 1 to 3 carbon atoms, from the viewpoint of easy availability. More preferably, it is an alkyl group.
• R 6 is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and more preferably a hydrogen atom.
• R 7 and R 8 are independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and a hydrogen atom. Is more preferable.
• R 9 to R 11 are preferably hydrogen atoms or alkyl groups having 1 to 10 carbon atoms from the viewpoint of easy availability.
• R 12 is preferably a hydroxy group, an amino group, or an alkoxy group from the viewpoint of easy availability.
• n is preferably 1 from the viewpoint of easy availability.
• the N-oxyl compound is described in, for example, JP-A-2003-64022, JP-A-11-222462, JP-A-2002-284737, and WO-A-2016 / 047655. An oxyl compound is mentioned.
• Examples of the compound having a nitroxy radical or a nitroxide group include the following compounds.
• R represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, an acyl group, or an aryl group.
• the compound having a nitroxy radical or a nitroxide group has a molecular weight of preferably 1,000 or less, more preferably 500 or less, from the viewpoint of efficiently trapping a radical generated in a polyene reaction. It is more preferably 300 or less.
• the content of the compound having a nitroxyl radical or a nitroxide group in the polarizing film is preferably 20% by weight or less.
• the content of the compound having a nitroxyl radical or a nitroxide group is 0.005% by weight or more from the viewpoint of suppressing a decrease in single transmittance due to coloring of the polarizing film in a high temperature environment. Is more preferable, 0.01% by weight or more is more preferable, 0.02% by weight or more is further preferable, and 15% by weight or less is preferable, and 12% by weight or less is more preferable. It is preferably 10% by weight or less, and more preferably 10% by weight or less.
• the method for producing a polarizing film of the present invention is obtained by subjecting the polyvinyl alcohol film to an optional swelling step and a washing step, and at least a dyeing step, a crosslinking step, and a stretching step, the swelling step and the washing step.
• the treatment bath in one or more treatment steps of the dyeing step, the crosslinking step, and the stretching step contains a compound having a nitroxy radical or a nitroxide group.
• the content of the compound having a nitroxy radical or a nitroxide group and the content of iodine contained in the polarizing film is any one of the treatment baths in the swelling step, the dyeing step, the crosslinking step, the stretching step and the washing step. It can be controlled by the concentration of the compound having a nitroxyl radical or a nitroxide group contained in the above, the concentration of iodine and potassium iodide, the treatment temperature and the treatment time in each treatment bath described above.
• the washing step when the washing step is performed after the dyeing step, the cross-linking step, and the stretching step, the washing step considers the treatment conditions in the dyeing step, the cross-linking step, and the stretching step, and then the nitroxy radical.
• the content of the nitroxy radical or a compound having a nitroxide group and the iodine It is easy to adjust the content of to the desired range.
• each treatment bath in the swelling step, the dyeing step, the crosslinking step, the stretching step and the washing step contains an additive such as a zinc salt, a pH adjusting agent, a pH buffering agent and other salts.
• a zinc salt include zinc halides such as zinc chloride and zinc iodide; inorganic zinc salts such as zinc sulfate and zinc acetate.
• the pH adjuster include strong acids such as hydrochloric acid, sulfuric acid and nitric acid, and strong bases such as sodium hydroxide and potassium hydroxide.
• Examples of the pH buffer include carboxylic acids such as acetic acid, oxalic acid and citric acid and salts thereof, and weak inorganic acids such as phosphoric acid and carbonic acid and salts thereof.
• Examples of the other salts include chlorides such as sodium chloride, potassium chloride and barium chloride, nitrates such as sodium nitrate and potassium nitrate, sulfates such as sodium sulfate and potassium sulfate, and alkali metals and alkaline earth metals. Salt etc. are mentioned.
• the concentration of the compound having a nitroxyl radical or a nitroxide group contained in any of the treatment baths cannot be unconditionally determined because it is affected by the number of treatments, the treatment time, the treatment temperature of each treatment, etc.
• the content is usually preferably 0.01% by weight or more, more preferably 0.05% by weight or more, It is more preferably 0.1% by weight or more, and preferably 30% by weight or less, more preferably 25% by weight or less, and further preferably 20% by weight or less.
• the swelling step is a treatment step of immersing the polyvinyl alcohol-based film in a swelling bath, which can remove stains and blocking agents on the surface of the polyvinyl alcohol-based film, and can also be dyed by swelling the polyvinyl alcohol-based film. Unevenness can be suppressed.
• a medium containing water as a main component such as water, distilled water, or pure water, is usually used.
• a surfactant, alcohol, etc. may be appropriately added according to a conventional method.
• the temperature of the swelling bath is preferably about 10 to 60 ° C, more preferably about 15 to 45 ° C, and even more preferably about 18 to 30 ° C.
• the dipping time in the swelling bath cannot be unconditionally determined because the degree of swelling of the polyvinyl alcohol film is affected by the temperature of the swelling bath, but is preferably about 5 to 300 seconds, and preferably 10 to 200 seconds. It is more preferably about 10 to 100 seconds, still more preferably about 20 to 100 seconds.
• the swelling step may be performed only once, or may be performed multiple times as necessary.
• the dyeing step is a step of immersing the polyvinyl alcohol film in a dyeing bath (iodine solution), and iodine can be adsorbed and oriented on the polyvinyl alcohol film.
• the iodine solution is preferably an aqueous iodine solution and contains iodine and iodide as a dissolution aid.
• the iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and iodide.
• examples include titanium.
• potassium iodide is preferable from the viewpoint of controlling the content of potassium in the polarizing film.
• the iodine concentration in the dyeing bath is preferably about 0.01 to 1% by weight, more preferably about 0.02 to 0.5% by weight.
• the iodide concentration is preferably about 0.01 to 20% by weight, more preferably about 0.05 to 10% by weight, and about 0.1 to 5% by weight. It is more preferable that there is.
• the temperature of the dyeing bath is preferably about 10 to 50 ° C., more preferably about 15 to 45 ° C., and further preferably about 18 to 30 ° C.
• the immersion time in the dyeing bath cannot be unconditionally determined because the degree of dyeing of the polyvinyl alcohol film is affected by the temperature of the dyeing bath, but it is preferably about 10 to 300 seconds, and 20 to 240 seconds. It is more preferable that the degree is approximately.
• the dyeing step may be performed only once, or may be performed multiple times as necessary.
• the cross-linking step is a step of immersing the polyvinyl alcohol-based film in a treatment bath containing a boron compound (cross-linking bath), and the polyvinyl alcohol-based film is cross-linked by the boron compound, and the iodine molecule or the dye molecule is cross-linked. Can be adsorbed on the structure.
• the boron compound include boric acid, borate, and borax.
• the cross-linking bath is generally an aqueous solution, but may be, for example, a mixed solution of an organic solvent miscible with water and water. Further, the crosslinking bath may contain potassium iodide from the viewpoint of controlling the content of potassium in the polarizing film.
• the concentration of the boron compound in the crosslinking bath is preferably about 1 to 15% by weight, more preferably about 1.5 to 10% by weight, and even more preferably about 2 to 5% by weight. preferable.
• concentration of potassium iodide in the crosslinking bath is preferably about 1 to 15% by weight, more preferably about 1.5 to 10% by weight. More preferably, it is more preferably about 2 to 5% by weight.
• the temperature of the crosslinking bath is preferably about 20 to 70 ° C, more preferably about 30 to 60 ° C.
• the immersion time in the crosslinking bath cannot be unconditionally determined because the degree of crosslinking of the polyvinyl alcohol film is affected by the temperature of the crosslinking bath, but it is preferably about 5 to 300 seconds, preferably 10 to 200 seconds. It is more preferable that the degree is approximately.
• the cross-linking step may be performed only once, or may be performed multiple times as necessary.
• the stretching step is a treatment step of stretching the polyvinyl alcohol film in at least one direction at a predetermined ratio.
• a polyvinyl alcohol film is uniaxially stretched in the transport direction (longitudinal direction).
• the stretching method is not particularly limited, and either a wet stretching method or a dry stretching method can be adopted.
• the stretching step may be performed only once, or may be performed multiple times as necessary.
• the stretching process may be performed at any stage in manufacturing the polarizing film.
• the stretching bath may contain potassium iodide from the viewpoint of controlling the content of the potassium in the polarizing film.
• the concentration of potassium iodide in the stretching bath is preferably about 1 to 15% by weight, more preferably about 2 to 10% by weight, and 3 It is more preferably about 6 to 6% by weight.
• the treatment bath (stretching bath) may contain the boron compound from the viewpoint of suppressing film breakage during stretching, and in this case, the concentration of the boron compound in the stretching bath is 1 to 15. It is preferably about wt%, more preferably about 1.5 to 10 wt%, and even more preferably about 2 to 5 wt%.
• the temperature of the stretching bath is preferably about 25 to 80 ° C, more preferably about 40 to 75 ° C, and further preferably about 50 to 70 ° C.
• the dipping time in the stretching bath cannot be unconditionally determined because the extent of stretching of the polyvinyl alcohol film is affected by the temperature of the stretching bath, but is preferably about 10 to 800 seconds, and preferably 30 to 500 seconds. It is more preferable that the degree is approximately.
• the stretching treatment in the wet stretching method may be performed together with one or more treatment steps of the swelling step, the dyeing step, the crosslinking step, and the washing step.
• Examples of the dry stretching method include a roll stretching method, a heated roll stretching method, and a compression stretching method.
• the dry stretching method may be performed together with the drying step.
• the total draw ratio (cumulative draw ratio) applied to the polyvinyl alcohol film can be appropriately set according to the purpose, but it is preferably about 2 to 7 times, and preferably about 3 to 6.8 times. More preferably, it is more preferably about 3.5 to 6.5 times.
• the cleaning step is a treatment step of immersing the polyvinyl alcohol-based film in a cleaning bath, and foreign substances remaining on the surface of the polyvinyl alcohol-based film can be removed.
• a medium containing water as a main component such as water, distilled water, or pure water, is usually used.
• the cleaning bath may contain potassium iodide.
• the concentration of potassium iodide in the cleaning bath is 1 to 10% by weight. %, Preferably about 1.5 to 4% by weight, more preferably about 1.8 to 3.8% by weight.
• the temperature of the washing bath is preferably about 5 to 50 ° C, more preferably about 10 to 40 ° C, and further preferably about 15 to 35 ° C.
• the dipping time in the washing bath cannot be unconditionally determined because the washing degree of the polyvinyl alcohol film is affected by the temperature of the washing bath, but it is preferably about 1 to 100 seconds, and preferably 2 to 50 seconds. It is more preferably about 3 to 20 seconds.
• the swelling step may be performed only once, or may be performed multiple times as necessary.
• the method for producing a polarizing film of the present invention may include a drying step.
• the drying step is a step of drying the polyvinyl alcohol film washed in the washing step to obtain a polarizing film, and by drying, a polarizing film having a desired moisture content is obtained.
• the drying is performed by any appropriate method, and examples thereof include natural drying, blast drying, and heat drying.
• the drying temperature is preferably about 20 to 150 ° C, more preferably about 25 to 100 ° C.
• the drying time cannot be unconditionally determined because the drying degree of the polarizing film is affected by the drying temperature, but is preferably about 10 to 600 seconds, more preferably about 30 to 300 seconds. preferable.
• the drying step may be performed only once, or may be performed multiple times as necessary.
• the thickness of the polarizing film is preferably about 1 to 50 ⁇ m, more preferably about 1 to 25 ⁇ m.
• a laminate including a polyvinyl alcohol-based resin layer formed on a resin base material such as a thermoplastic resin is used as the polyvinyl alcohol-based film.
• a method of manufacturing a thin polarizing film can be applied.
• the method for producing a polarizing film (thin polarizing film) includes a step of forming a polyvinyl alcohol-based resin layer containing a polyvinyl alcohol-based resin on one side of a long thermoplastic resin substrate, and preparing a laminate, While conveying the obtained laminated body in the longitudinal direction, an insolubilization treatment step, a cross-linking treatment step, and a washing treatment step, and at least an in-air auxiliary stretching treatment step, a dyeing treatment step, and an underwater stretching treatment step are performed on the laminated body.
• the treatment bath obtained in any one or more of the insolubilization treatment step, the crosslinking treatment step, the washing treatment step, the dyeing treatment step, and the underwater stretching treatment step is a nitroxy radical, Alternatively, it includes a compound having a nitroxide group.
• the washing treatment step should be performed in consideration of treatment conditions such as a dyeing treatment step and an underwater stretching treatment step, and then a compound such as a compound having a nitroxyl radical or a nitroxide group or iodine.
• treatment conditions such as a dyeing treatment step and an underwater stretching treatment step
• a compound such as a compound having a nitroxyl radical or a nitroxide group or iodine.
• a compound having a nitroxyl radical or a nitroxide group or iodine From the viewpoint of being able to be eluted from the polyvinyl alcohol-based film or adsorbed to the polyvinyl alcohol-based film, it is easy to adjust the content of the compound having a nitroxy radical or a nitroxide group and the content of iodine to a desired range.
• the concentration of the nitroxy radical or the compound having a nitroxide group contained in any of the treatment baths cannot be unconditionally determined because it is affected by the treatment number of each treatment, treatment time, treatment temperature, etc. From the viewpoint of efficiently controlling the content of a compound having a nitroxyl radical or a nitroxide group, it is usually preferably 0.01% by weight or more, more preferably 0.05% by weight or more, It is more preferably 0.1% by weight or more, and preferably 30% by weight or less, more preferably 25% by weight or less, and further preferably 20% by weight or less.
• thermoplastic resin substrate is preferably about 20 to 300 ⁇ m, more preferably about 50 to 200 ⁇ m.
• the thickness of the PVA-based resin layer is preferably about 3 to 40 ⁇ m, more preferably about 3 to 20 ⁇ m.
• the thermoplastic resin base material preferably has a water absorption rate of about 0.2% or more, from the viewpoint of absorbing water to significantly reduce the stretching stress and allowing stretching to a high ratio, and 0.3. % Or more is more preferable.
• the thermoplastic resin base material has a water absorption of 3 from the viewpoint that the dimensional stability of the thermoplastic resin base material is remarkably reduced and the appearance of the obtained polarizing film is deteriorated. % Or less, more preferably about 1% or less.
• the water absorption can be adjusted, for example, by introducing a modifying group into the constituent material of the thermoplastic resin substrate.
• the water absorption rate is a value obtained according to JIS K7209.
• the thermoplastic resin base material has a glass transition temperature (Tg) of about 120 ° C. or lower from the viewpoint of being able to sufficiently secure the stretchability of the laminate while suppressing the crystallization of the PVA-based resin layer. Is preferred. Further, in consideration of the plasticization of the thermoplastic resin substrate with water and the favorable underwater drawing, the glass transition temperature (Tg) is more preferably about 100 ° C. or lower, and about 90 ° C. or lower. Is more preferable. On the other hand, the glass transition temperature of the thermoplastic resin substrate is such that when the coating liquid is applied and dried, problems such as deformation of the thermoplastic resin substrate can be prevented and a good laminate can be produced. Therefore, the temperature is preferably about 60 ° C. or higher. The glass transition temperature can be adjusted, for example, by introducing a modifying group into the constituent material of the thermoplastic resin substrate or by heating with a crystallization material. The glass transition temperature (Tg) is a value determined according to JIS K7121.
• thermoplastic resin can be adopted as the constituent material of the thermoplastic resin base material.
• the thermoplastic resin include ester resins such as polyethylene terephthalate resins, cycloolefin resins such as norbornene resins, olefin resins such as polypropylene, polyamide resins, polycarbonate resins, and copolymer resins thereof. Etc. Among these, norbornene-based resins and amorphous (amorphous) polyethylene terephthalate-based resins are preferable. Further, the thermoplastic resin base material has extremely excellent stretchability, and from the viewpoint that crystallization during stretching can be suppressed. Amorphous (non-crystalline) polyethylene terephthalate resin is preferably used.
• amorphous (amorphous) polyethylene terephthalate-based resin examples include a copolymer containing isophthalic acid and / or cyclohexanedicarboxylic acid as a dicarboxylic acid, and a copolymer containing cyclohexanedimethanol or diethylene glycol as a glycol.
• the thermoplastic resin substrate may be subjected to a surface treatment (for example, corona treatment) before forming the PVA-based resin layer, or an easy adhesion layer may be formed on the thermoplastic resin substrate. . By performing such a treatment, it is possible to improve the adhesion between the thermoplastic resin substrate and the PVA-based resin layer.
• the thermoplastic resin substrate may be stretched before forming the PVA-based resin layer.
• the above coating solution is a solution of PVA resin dissolved in a solvent.
• the solvent include water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, various glycols, polyhydric alcohols such as trimethylolpropane, amines such as ethylenediamine and diethylenetriamine, and water. preferable. These can be used alone or in combination of two or more.
• the concentration of the PVA-based resin in the coating liquid is preferably about 3 to 20 parts by weight based on 100 parts by weight of the solvent, from the viewpoint of forming a uniform coating film in close contact with the thermoplastic resin substrate. ..
• the coating liquid contains a halide.
• Any appropriate halide can be adopted as the halide, and examples thereof include iodide and sodium chloride.
• the iodide include potassium iodide, sodium iodide, lithium iodide and the like, and potassium iodide is preferable.
• the concentration of the halide in the coating liquid is preferably about 5 to 20 parts by weight, more preferably about 10 to 15 parts by weight, based on 100 parts by weight of the PVA-based resin.
• additives may be added to the coating liquid.
• the additives include plasticizers such as ethylene glycol and glycerin; surfactants such as nonionic surfactants.
• any appropriate method can be adopted as a method for applying the coating solution, and examples thereof include a roll coating method, a spin coating method, a wire bar coating method, a dip coating method, a die coating method, a curtain coating method, and a spray coating method. , Knife coating method (comma coating method, etc.) and the like.
• the drying temperature of the coating liquid is preferably about 50 ° C or higher.
• the stretching method of the in-air auxiliary stretching treatment step may be fixed-end stretching (for example, a method of stretching using a tenter stretching machine) or free-end stretching (for example, uniaxial stretching through a laminate between rolls having different peripheral speeds). Method), but free end drawing is preferable from the viewpoint of obtaining high optical characteristics.
• the draw ratio in the above-mentioned in-air auxiliary drawing process is preferably about 2 to 3.5 times.
• the in-air auxiliary stretching treatment may be performed in one stage or in multiple stages. When performing in multiple stages, the draw ratio is the product of the draw ratios of the respective stages.
• the stretching temperature in the in-air auxiliary stretching treatment step can be set to any appropriate value depending on the forming material of the thermoplastic resin substrate, the stretching method, and the like.
• the glass transition temperature of the thermoplastic resin substrate It is preferably (Tg) or higher, more preferably the glass transition temperature (Tg) + 10 ° C. or higher, and further preferably the glass transition temperature (Tg) + 15 ° C. or higher.
• the upper limit of the stretching temperature is from the viewpoint that the crystallization of the PVA-based resin can be prevented from rapidly progressing and defects due to crystallization (for example, hindering the orientation of the PVA-based resin layer due to the stretching) can be suppressed. It is preferably about 170 ° C.
• an insolubilization treatment step may be performed after the in-air auxiliary stretching treatment step and before the dyeing treatment step or the underwater stretching treatment step.
• the insolubilization treatment step is typically performed by immersing the PVA-based resin layer in an aqueous boric acid solution. By performing the insolubilization treatment step, it is possible to impart water resistance to the PVA-based resin layer and prevent the orientation of PVA from being lowered when immersed in water.
• the concentration of the boric acid aqueous solution is preferably about 1 to 5 parts by weight with respect to 100 parts by weight of water.
• the liquid temperature of the insolubilization bath is preferably about 20 to 50 ° C.
• the dyeing treatment step is performed by dyeing the PVA-based resin layer with iodine.
• the adsorption method include a method of immersing the PVA-based resin layer (laminate) in a dyeing solution containing iodine, a method of applying the dyeing solution to the PVA-based resin layer, and a method of applying the dyeing solution to the PVA-based resin layer. Examples thereof include a method of spraying, and a method of immersing the PVA-based resin layer (laminate) in a dyeing solution containing iodine is preferable.
• the blending amount of iodine in the dyeing bath is preferably about 0.05 to 0.5 parts by weight with respect to 100 parts by weight of water.
• the iodide content is preferably about 0.1 to 10 parts by weight, and more preferably about 0.3 to 5 parts by weight, based on 100 parts by weight of water.
• the liquid temperature of the dyeing bath is preferably about 20 to 50 ° C. in order to suppress dissolution of the PVA-based resin.
• the immersion time is preferably about 5 seconds to 5 minutes, and more preferably about 30 seconds to 90 seconds, from the viewpoint of ensuring the transmittance of the PVA-based resin layer.
• the ratio of the iodine and iodide contents in the iodine aqueous solution is preferably about 1: 5 to 1:20, and about 1: 5 to 1:10. More preferably.
• a crosslinking treatment step may be performed after the dyeing treatment step and before the underwater stretching treatment step.
• the cross-linking treatment step is typically performed by immersing the PVA-based resin layer in an aqueous boric acid solution.
• the boric acid concentration of the aqueous boric acid solution is preferably about 1 to 5 parts by weight with respect to 100 parts by weight of water.
• the crosslinking bath further contains the iodide.
• the iodide content is preferably about 1 to 5 parts by weight with respect to 100 parts by weight of water.
• the liquid temperature of the crosslinking bath is preferably about 20 to 50 ° C.
• the underwater stretching treatment step is performed by immersing the laminate in a stretching bath. According to the underwater stretching treatment step, it is possible to stretch at a temperature lower than the glass transition temperature (typically about 80 ° C.) of the thermoplastic resin base material or the PVA type resin layer, and the PVA type resin layer is crystallized. It is possible to stretch at a high magnification while suppressing the above.
• the stretching method in the underwater stretching treatment step may be fixed-end stretching (for example, a stretching method using a tenter stretching machine) or free-end stretching (for example, a uniaxial stretching method in which a laminate is passed between rolls having different peripheral speeds). ) May be used, but free-end stretching is preferable from the viewpoint of obtaining high optical characteristics.
• the above-mentioned underwater stretching treatment step is preferably performed by immersing the laminate in a boric acid aqueous solution (boric acid underwater stretching).
• a boric acid aqueous solution boric acid underwater stretching
• the boric acid concentration of the boric acid aqueous solution is preferably 1 to 10 parts by weight, and more preferably 2.5 to 6 parts by weight with respect to 100 parts by weight of water.
• the liquid temperature of the stretching bath is preferably about 40 to 85 ° C, more preferably about 60 to 75 ° C.
• the immersion time of the laminate in the stretching bath is preferably about 15 seconds to 5 minutes.
• the draw ratio in the underwater stretching process is preferably about 1.5 times or more, more preferably about 3 times or more.
• the total draw ratio of the laminate is preferably about 5 times or more, more preferably about 5.5 times or more of the original length of the laminate.
• the cleaning treatment step is typically performed by immersing the PVA-based resin layer in an aqueous potassium iodide solution.
• each treatment bath in the dyeing treatment step, the underwater stretching treatment step, the insolubilization treatment step, the cross-linking treatment step, and the washing treatment step contains zinc salt, a pH adjusting agent, a pH buffering agent, and other salts. It may contain various additives.
• the zinc salt include zinc halides such as zinc chloride and zinc iodide; inorganic zinc salts such as zinc sulfate and zinc acetate.
• the pH adjuster include strong acids such as hydrochloric acid, sulfuric acid and nitric acid, and strong bases such as sodium hydroxide and potassium hydroxide.
• Examples of the pH buffer include carboxylic acids such as acetic acid, oxalic acid and citric acid and salts thereof, and weak inorganic acids such as phosphoric acid and carbonic acid and salts thereof.
• Examples of the other salts include chlorides such as sodium chloride, potassium chloride and barium chloride, nitrates such as sodium nitrate and potassium nitrate, sulfates such as sodium sulfate and potassium sulfate, and alkali metals and alkaline earth metals. Salt etc. are mentioned.
• a transparent protective film is attached to at least one surface of the polarizing film.
• the transparent protective film is not particularly limited, and various transparent protective films used for polarizing films can be used.
• a material forming the transparent protective film for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, etc. is used.
• the thermoplastic resin include cellulose ester resins such as triacetyl cellulose, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyether sulfone resins, polysulfone resins, polycarbonate resins, nylon and aroma.
• Polyamide resins such as group polyamides, polyimide resins, polyolefin resins such as polyethylene, polypropylene and ethylene-propylene copolymers, (meth) acrylic resins, cyclo polyolefin resins having a norbornene structure (norbornene resins) ), Polyarylate-based resins, polystyrene-based resins, polyvinyl alcohol-based resins, and mixtures thereof.
• the transparent protective film may use a cured layer formed of a thermosetting resin such as a (meth) acrylic resin, a urethane resin, an acryl urethane resin, an epoxy resin, a silicone resin or an ultraviolet curable resin.
• a cellulose ester resin, a polycarbonate resin, a (meth) acrylic resin, a cyclic polyolefin resin, and a polyester resin are preferable.
• the thickness of the transparent protective film can be appropriately determined, but generally, from the viewpoint of workability such as strength and handleability, thin layer property, etc., it is preferably about 1 to 500 ⁇ m, and about 1 to 300 ⁇ m. More preferably, it is more preferably about 5 to 100 ⁇ m.
• the transparent protective films on both sides may be the same or different.
• a retardation plate having a front surface retardation of 40 nm or more and / or a thickness direction retardation of 80 nm or more can be used.
• the front retardation is usually controlled in the range of 40 to 200 nm
• the thickness direction retardation is usually controlled in the range of 80 to 300 nm.
• the retardation plate also functions as a transparent protective film, so that the thickness can be reduced.
• the retardation plate examples include a birefringent film obtained by uniaxially or biaxially stretching a polymer material, a liquid crystal polymer alignment film, and a liquid crystal polymer alignment layer supported by a film.
• the thickness of the retardation plate is not particularly limited, but is generally about 20 to 150 ⁇ m.
• the phase plate may be attached to a transparent protective film having no retardation.
• the transparent protective film contains any appropriate additive such as an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a release agent, an anti-coloring agent, a flame retardant, an antistatic agent, a pigment and a colorant. You may stay. In particular, when the transparent protective film contains an ultraviolet absorber, the light resistance of the polarizing film can be improved.
• a functional layer such as a hard coat layer, an antireflection layer, a sticking prevention layer, a diffusion layer or an antiglare layer can be provided on the surface of the transparent protective film on which the polarizing film is not attached.
• the hard coat layer, the antireflection layer, the antisticking layer, the functional layer such as the diffusion layer and the antiglare layer may be provided on the protective film itself, or may be provided separately from the protective film. it can.
• the polarizing film and the transparent protective film, or the polarizing film and the functional layer are usually attached via an adhesive layer or an adhesive layer.
• various pressure-sensitive adhesives used in polarizing films can be applied, and examples thereof include rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, and vinyl-based pressure-sensitive adhesives. Examples thereof include alkyl ether-based adhesives, polyvinyl alcohol-based adhesives, polyvinylporolidone-based adhesives, polyacrylamide-based adhesives, and cellulose-based adhesives. Among these, acrylic adhesives are suitable.
• a method of forming the pressure-sensitive adhesive layer for example, a method of applying the pressure-sensitive adhesive to a release-treated separator or the like, forming a pressure-sensitive adhesive layer by drying, and then transferring to a polarizing film, or the pressure-sensitive adhesive is polarized. Examples thereof include a method of forming a pressure-sensitive adhesive layer by applying it on a film or the like and drying it.
• the thickness of the pressure-sensitive adhesive layer is not particularly limited and is, for example, about 1 to 100 ⁇ m, preferably about 2 to 50 ⁇ m.
• various adhesives used in polarizing films can be applied, for example, isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latex adhesives, Examples include water-based polyester. These adhesives are usually used as an adhesive composed of an aqueous solution (water-based adhesive) and contain a solid content of 0.5 to 60% by weight. Among these, polyvinyl alcohol adhesives are preferable, and acetoacetyl group-containing polyvinyl alcohol adhesives are more preferable.
• the water-based adhesive may contain a crosslinking agent.
• a crosslinking agent a compound having at least two functional groups reactive with a component such as a polymer constituting an adhesive in one molecule is usually used, and examples thereof include alkylenediamines; isocyanates; epoxies; Aldehydes; amino-formaldehyde and the like such as methylol urea and methylol melamine.
• the compounding amount of the crosslinking agent in the adhesive is usually about 10 to 60 parts by weight with respect to 100 parts by weight of the components such as the polymer constituting the adhesive.
• examples of the adhesive include active energy ray curable adhesives such as ultraviolet curable adhesives and electron beam curable adhesives.
• active energy ray-curable adhesive include (meth) acrylate adhesives.
• examples of the curable component in the (meth) acrylate-based adhesive include compounds having a (meth) acryloyl group and compounds having a vinyl group.
• examples of the compound having a (meth) acryloyl group include alkyl (meth) acrylates such as a chain alkyl (meth) acrylate having 1 to 20 carbon atoms, an alicyclic alkyl (meth) acrylate, and a polycyclic alkyl (meth) acrylate.
• (Meth) acrylate adhesives include hydroxyethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, (meth) acrylamide, (meth) It may contain a nitrogen-containing monomer such as acryloylmorpholine.
• the (meth) acrylate-based adhesive includes tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane formal acrylate, dioxane glycol diacrylate, and EO as cross-linking components. It may contain a polyfunctional monomer such as modified diglycerin tetraacrylate. Further, a compound having an epoxy group or an oxetanyl group can also be used as the cationic polymerization curable adhesive.
• the compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various commonly known curable epoxy compounds can be used.
• the adhesive may contain an appropriate additive as needed.
• the additives include silane coupling agents, coupling agents such as titanium coupling agents, adhesion promoters such as ethylene oxide, ultraviolet absorbers, deterioration inhibitors, dyes, processing aids, ion trap agents, and antioxidants.
• the application of the adhesive may be performed on either the transparent protective film side (or the functional layer side), the polarizing film side, or both.
• a drying process is performed to form an adhesive layer composed of a coating and drying layer.
• ultraviolet rays or an electron beam can be irradiated if necessary.
• the thickness of the adhesive layer is not particularly limited, and when an aqueous adhesive or the like is used, it is preferably about 30 to 5000 nm, more preferably about 100 to 1000 nm, and an ultraviolet curable adhesive. When using an electron beam curable adhesive or the like, the thickness is preferably about 0.1 to 100 ⁇ m, more preferably about 0.5 to 10 ⁇ m.
• the transparent protective film and the polarizing film, or the polarizing film and the functional layer may be laminated via an intervening layer such as a surface modification treatment layer, an easy-adhesive layer, a block layer, and a refractive index adjusting layer. ..
• Examples of the surface modification treatment for forming the surface modification layer include corona treatment, plasma treatment, primer treatment, saponification treatment and the like.
• Examples of the easy-adhesive agent for forming the easy-adhesion layer include a forming material containing various resins having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone-based, a polyamide skeleton, a polyimide skeleton, a polyvinyl alcohol skeleton, or the like. Can be mentioned.
• the easy-adhesion layer is usually provided in advance on the protective film, and the easy-adhesion layer side of the protective film and the polarizing film are laminated with the pressure-sensitive adhesive layer or the adhesive layer.
• the blocking layer is a layer that has a function of preventing impurities (such as oligomers and ions) eluted from the transparent protective film and the like from moving (entering) into the polarizing film.
• the block layer may be any layer as long as it has transparency and can prevent impurities eluted from the transparent protective film and the like, and examples of the material for forming the block layer include urethane prepolymer-based forming material and cyanoacrylate. Examples include a system forming material and an epoxy forming material.
• the refractive index adjusting layer is a layer provided for suppressing a decrease in transmittance due to reflection between the transparent protective film and a layer such as a polarizing film having a different refractive index.
• the refractive index adjusting material for forming the refractive index adjusting layer include various resins having a silica type, an acrylic type, an acryl-styrene type, a melamine type, etc., and a forming agent containing an additive.
• the laminated polarizing film (optical laminate) of the present invention is one in which the polarizing film is attached to an optical layer.
• the optical layer is not particularly limited, but for example, for forming a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including a wavelength plate such as 1/2 or 1/4), and a viewing angle compensation film.
• a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including a wavelength plate such as 1/2 or 1/4), and a viewing angle compensation film.
• One or two or more optical layers that may be used can be used.
• a reflective polarizing film or a semi-transmissive polarizing film obtained by further laminating a reflecting plate or a semi-transmissive reflecting plate on the polarizing film, and further comprising a retardation plate laminated on the polarizing film.
• a reflective polarizing film or a semi-transmissive polarizing film obtained by further laminating a reflecting plate or a semi-transmissive reflecting plate on the polarizing film, and further comprising a retardation plate laminated on the polarizing film.
• Examples thereof include an elliptically polarizing film or a circularly polarizing film, a wide viewing angle polarizing film obtained by further laminating a viewing angle compensation film on the polarizing film, or a polarizing film obtained by further laminating a brightness improving film on the polarizing film.
• an image display cell such as a liquid crystal cell or an organic EL element
• another front transparent member such as a front transparent plate or a touch panel on the viewing side
• An adhesive layer for attaching the members may be additionally provided.
• a pressure-sensitive adhesive layer is suitable as the adhesive layer.
• the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited, but for example, an acrylic polymer, a silicone-based polymer, polyester, polyurethane, polyamide, polyether, or a polymer having a fluorine-based or rubber-based polymer as a base polymer It can be appropriately selected and used.
• a pressure-sensitive adhesive containing an acrylic polymer which has excellent optical transparency, shows appropriate wettability, cohesiveness and adhesiveness, and has excellent weather resistance and heat resistance, is preferably used.
• the adhesive layer may be attached to one side or both sides of the polarizing film or the laminated polarizing film by an appropriate method.
• a method of preparing a pressure-sensitive adhesive solution and directly attaching it to the polarizing film or the laminated polarizing film by an appropriate developing method such as a casting method or a coating method, or a separator Examples include a method in which an adhesive layer is formed on the adhesive layer and transferred onto the polarizing film or the laminated polarizing film.
• the thickness of the pressure-sensitive adhesive layer can be appropriately determined depending on the purpose of use, adhesive strength, etc., and is generally 1 to 500 ⁇ m, preferably 5 to 200 ⁇ m, and more preferably 10 to 100 ⁇ m.
• the polarizing film or the laminated polarizing film provided with the adhesive layer on at least one surface thereof is referred to as an adhesive layer-attached polarizing film or an adhesive layer-attached laminated polarizing film.
• the exposed surface of the pressure-sensitive adhesive layer is temporarily attached and covered with a separator for practical use until it is put to practical use.
• a separator for example, a plastic film, a rubber sheet, a paper, a cloth, a non-woven fabric, a net, a foam sheet or a metal foil, an appropriate thin sheet such as a laminate thereof, a silicone-based or long-chain alkyl-based, if necessary, Those coated with an appropriate release agent such as fluorine-based or molybdenum sulfide are used.
• the image display panel of the present invention is one in which the polarizing film or the laminated polarizing film is attached to an image display cell.
• the image display device of the present invention includes a front transparent member on the polarizing film or laminated polarizing film side (viewing side) of the image display panel.
• Examples of the image display cell include a liquid crystal cell and an organic EL cell.
• Examples of the liquid crystal cell include a reflective liquid crystal cell that uses external light, a transmissive liquid crystal cell that uses light from a light source such as a backlight, and a semi-transmissive liquid crystal cell that uses both external light and light from a light source. Any of the semi-reflective liquid crystal cells may be used.
• the image display device liquid crystal display device
• the image display device has a polarizing film arranged on the side opposite to the viewing side of the image display cell (liquid crystal cell). Will be placed. It is preferable that the polarizing film on the light source side and the liquid crystal cell are bonded together via an appropriate adhesive layer.
• any type such as a VA mode, an IPS mode, a TN mode, an STN mode, a bend alignment ( ⁇ type), or the like can be used.
• organic EL cell for example, one in which a transparent electrode, an organic light emitting layer, and a metal electrode are laminated in this order on a transparent substrate to form a light emitting body (organic electroluminescent light emitting body) is preferably used.
• the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light emitting layer made of a fluorescent organic solid such as anthracene, or the like.
• Various layer configurations such as a laminated body of the above-mentioned light emitting layer and an electron injection layer composed of a perylene derivative or a laminated body of a hole injection layer, a light emitting layer, and an electron injection layer can be adopted.
• the front transparent member arranged on the viewing side of the image display cell includes, for example, a front transparent plate (window layer) and a touch panel.
• a transparent plate having appropriate mechanical strength and thickness is used.
• a transparent plate for example, a transparent resin plate such as an acrylic resin or a polycarbonate resin, or a glass plate is used.
• the touch panel for example, various touch panels such as a resistive film type, an electrostatic capacitance type, an optical type, an ultrasonic type, and a glass plate or a transparent resin plate having a touch sensor function are used.
• a capacitive touch panel is used as the front transparent member, it is preferable that a front transparent plate made of glass or a transparent resin plate is provided on the side closer to the viewer than the touch panel.
• ⁇ Example 1> ⁇ Production of polarizing film> A polyvinyl alcohol film having an average degree of polymerization of 2,400, a degree of saponification of 99.9 mol% and a thickness of 45 ⁇ m was prepared. The polyvinyl alcohol film was dipped in a swelling bath (water bath) at 20 ° C. for 30 seconds between rolls having different peripheral speed ratios and stretched to 2.2 times in the transport direction while swelling (swelling step). The iodine concentration of the polarizing film finally obtained in a dyeing bath at 30 ° C.
• a swelling bath water bath
• an iodine aqueous solution obtained by mixing iodine and potassium iodide in a weight ratio of 1: 7 to 100 parts by weight of water is 4 It is soaked for 30 seconds while adjusting the concentration to be 0.47% by weight, and dyed 3.3 times in the transport direction based on the original polyvinyl alcohol film (polyvinyl alcohol film that has not been stretched in the transport direction) while dyeing. Was stretched (dyeing step). Then, the dyed polyvinyl alcohol film is immersed in a crosslinking bath at 40 ° C.
• iodine concentration (% by weight) was determined using the following formula using a fluorescent X-ray analyzer (Rigaku Corporation, trade name “ZSX-PRIMUS IV”, measurement diameter: ⁇ 20 mm).
• Iodine concentration (wt%) 14.474 x (fluorescent X-ray intensity) / (film thickness) (kcps / ⁇ m)
• the coefficient for calculating the concentration differs depending on the measuring device, the coefficient is an appropriate calibration curve. Can be obtained using.
• ⁇ Production of polarizing film> polyvinyl alcohol resin containing acetoacetyl group (average polymerization degree: 1,200, saponification degree: 98.5 mol%, acetoacetylation degree: 5 mol%) and methylolmelamine in a weight ratio of 3: The aqueous solution contained in 1 was used.
• a triacetyl cellulose film having a hard coat layer and a thickness of 47 ⁇ m moisture permeability 342 g / (m 2 ⁇ 24 h)
• Konica Minolta (Product name: "KC4UYW”) is pasted with a roll laminating machine, and then dried by heating in an oven (temperature is 60 ° C, time is 4 minutes), and transparent protective films are pasted on both sides of the polarizing film.
• the obtained polarizing film was produced.
• the single transmittance of the polarizing film was 37.4%.
• the pressure-sensitive adhesive layer was applied so as to have a thickness of 20 ⁇ m and dried at 90 ° C. for 1 minute to form a pressure-sensitive adhesive layer on the surface of the separator film.
• the pressure-sensitive adhesive layer formed on the separator film was transferred onto one surface of the polarizing film prepared above to prepare a polarizing film with a pressure-sensitive adhesive layer.
• the polarizing film with the pressure-sensitive adhesive layer obtained above is cut into a size of 50 ⁇ 25 mm so that the absorption axis of the polarizing film is the long side, and a glass plate (pseudo image display cell) is attached via the pressure-sensitive adhesive layer. Together, a laminate was prepared. The obtained laminated body was allowed to stand in a hot air oven at a temperature of 105 ° C. for 300 hours, and the single-body transmittance ( ⁇ Ts) before and after charging (heating) was measured.
• ⁇ Ts single-body transmittance
• the simple substance transmittance was measured using a spectrophotometer (Murakami Color Research Laboratory Co., Ltd., product name "DOT-3"), and evaluated according to the following criteria.
• the single-piece transmittance is a Y value which has been subjected to luminosity correction by a 2 degree visual field (C light source) of JLS Z 8701-1982.
• the measurement wavelength is 380 to 700 nm (every 10 nm).
• the results are shown in Table 1.
• ⁇ Ts (%) Ts 300 ⁇ Ts 0
• Ts 0 is the simple substance transmittance of the laminate before heating
• Ts 300 is the simple substance transmittance of the laminate after heating for 300 hours.
• the ⁇ Ts (%) is preferably 5 ⁇ ⁇ Ts (%) ⁇ 0, and more preferably 3 ⁇ ⁇ Ts (%) ⁇ 0.
• Example 2> ⁇ Production of polarizing film and polarizing film>
• the concentration of iodine in the polarizing film finally obtained in the dyeing bath step was adjusted to 4.40% by weight, and the washing bath contains the nitro compound represented by the general formula (9).
• a polarizing film and a polarizing film were produced in the same manner as in Example 1, except that the compound having a xy radical or a nitroxide group was added so that the concentration was 2.0% by weight.
• the obtained polarizing film had a content of a compound having a nitroxyl radical or a nitroxide group of 0.94% by weight and a thickness of 18 ⁇ m.
• the single transmittance of the polarizing film was 37.7%.
• Example 3> ⁇ Production of polarizing film and polarizing film>
• the iodine concentration of the polarizing film finally obtained in the dyeing bath step was adjusted to 4.29% by weight, and the washing bath was prepared with the nitro compound represented by the general formula (9).
• a polarizing film and a polarizing film were produced in the same manner as in Example 1, except that the compound having a xy radical or a nitroxide group was added so that the concentration was 4.0% by weight.
• the obtained polarizing film had a content of a compound having a nitroxy radical or a nitroxide group of 2.4% by weight and a thickness of 18 ⁇ m.
• the single transmittance of the polarizing film was 37.9%.
• Example 4> ⁇ Production of polarizing film and polarizing film>
• the iodine concentration of the polarizing film finally obtained in the dyeing bath step was adjusted to 4.30% by weight, and the nitro compound represented by the general formula (9) was used in the washing bath.
• a polarizing film and a polarizing film were produced in the same manner as in Example 1, except that the compound having a xy radical or a nitroxide group was added so that the concentration was 10.0% by weight.
• the polarizing film obtained had a content of a compound having a nitroxy radical or a nitroxide group of 5.9% by weight and a thickness of 18 ⁇ m.
• the single transmittance of the polarizing film was 37.8%.
• Example 5> ⁇ Production of polarizing film and polarizing film>
• the iodine concentration of the polarizing film finally obtained in the dyeing bath step was adjusted to 4.12% by weight, and the nitro compound represented by the general formula (9) was used in the washing bath.
• a polarizing film and a polarizing film were produced in the same manner as in Example 1 except that the compound having a xy radical or a nitroxide group was added so that the concentration was 20.0% by weight.
• the obtained polarizing film had a content of a compound having a nitroxy radical or a nitroxide group of 11.1% by weight and a thickness of 18 ⁇ m.
• the single transmittance of the polarizing film was 38.2%.
• Example 6> ⁇ Production of polarizing film and polarizing film>
• the iodine concentration of the polarizing film finally obtained in the dyeing bath step was adjusted to 4.46% by weight, and the nitro compound represented by the general formula (9) was used in the washing bath.
• a compound having a nitroxyl radical represented by the general formula (10) or a compound having a nitroxide group was added so that the concentration was 0.4% by weight,
• a polarizing film and a polarizing film were produced.
• the obtained polarizing film had a content of a compound having a nitroxy radical or a nitroxide group of 0.19% by weight and a thickness of 18 ⁇ m.
• the single transmittance of the polarizing film was 37.6%.
• Example 7 ⁇ Production of polarizing film and polarizing film>
• the iodine concentration of the polarizing film finally obtained in the dyeing bath step was adjusted to be 2.38% by weight, and the nitro group represented by the general formula (9) was used in the stretching step.
• a polarizing film and a polarizing film were produced in the same manner as in Example 1, except that the compound having a xy radical or a nitroxide group was added so that the concentration was 0.05% by weight.
• the obtained polarizing film had a content of a compound having a nitroxy radical or a nitroxide group of 0.03% by weight and a thickness of 18 ⁇ m.
• the single transmittance of the polarizing film was 43.1%.
• thermoplastic resin base material an amorphous isophthalic copolymer polyethylene terephthalate film (thickness: 100 ⁇ m) having a long shape, a water absorption rate of 0.75% and a Tg of about 75 ° C. was used. Corona treatment was applied to one surface of the resin substrate.
• Polyvinyl alcohol (polymerization degree: 4200, saponification degree: 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosephimmer Z410") in a ratio of 9: 1 100 weight of PVA-based resin
• 13 parts by weight of potassium iodide was added to prepare a PVA aqueous solution (coating solution).
• the PVA aqueous solution was applied to the corona-treated surface of the resin substrate and dried at 60 ° C. to form a PVA-based resin layer having a thickness of 13 ⁇ m, and a laminate was prepared.
• the obtained laminate was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds in an oven at 130 ° C. (in-air auxiliary stretching treatment).
• the laminate was immersed in an insolubilization bath (solution of boric acid having a concentration of 4.0% by weight) having a liquid temperature of 40 ° C. for 30 seconds (insolubilization treatment).
• a dyeing bath having a liquid temperature of 30 ° C. (an iodine aqueous solution obtained by mixing iodine and potassium iodide in a weight ratio of 1: 7 with respect to 100 parts by weight of water) was added to the finally obtained polarizing film.
• the laminate was immersed in a washing bath at a liquid temperature of 30 ° C. (potassium iodide concentration 3% by weight and an aqueous solution having a compound concentration represented by the general formula (9) of 1.0% by weight) ( Cleaning process). Then, while being dried in an oven kept at 90 ° C., it was brought into contact with a SUS heating roll whose surface temperature was kept at 75 ° C. for about 2 seconds (dry shrinkage treatment). In this way, a polarizing film having a thickness of 5 ⁇ m was formed on the resin substrate. In addition, the content of the compound having a nitroxy radical or a nitroxide group in the obtained polarizing film was 0.18% by weight.
• a polyvinyl alcohol resin containing an acetoacetyl group (average polymerization degree: 1,200, saponification degree: 98.5 mol%, acetoacetylation degree: 5 mol%) and methylolmelamine were used in a weight ratio.
• An aqueous solution containing 3: 1 was used.
• a transparent protective film (thickness: 30 ⁇ m) made of a (meth) acrylic resin (modified acrylic polymer having a lactone ring structure) is formed on the surface of the polarizing film obtained above, which is opposite to the resin substrate.
• a film (manufactured by Nippon Shokubai Co., Ltd., moisture permeability of 125 g / (m 2 ⁇ 24 h)) was bonded using a roll bonding machine. Then, the resin substrate was peeled off, and as a transparent protective film on the peeled surface, a triacetyl cellulose film having a hard coat layer and a thickness of 47 ⁇ m (moisture permeability 342 g / (m 2 ⁇ 24 h), made by Konica Minolta, trade name “ KC4UYW ”) is pasted with a roll laminating machine via the following ultraviolet curable adhesive, and then the adhesive is cured by irradiating UV rays from the surface of the triacetyl cellulose film having the hard coat to cure the polarizing film.
• a triacetyl cellulose film having a hard coat layer and a thickness of 47 ⁇ m moisture permeability 342 g / (m 2 ⁇ 24 h),
• the single transmittance of the polarizing film was 42.8%. Further, the acrylic pressure-sensitive adhesive layer was transferred to the transparent protective film side made of acrylic resin in the same manner as in Example 1 to prepare a polarizing film with a pressure-sensitive adhesive layer.
• UV curable adhesive Details of the ultraviolet curable adhesive are as follows. An adhesive was prepared by mixing 40 parts by weight of N-hydroxyethylacrylamide (HEAA), 60 parts by weight of acryloylmorpholine (ACMO) and 3 parts by weight of a photoinitiator "IRGACURE 819" (manufactured by BASF). The adhesive layer after curing was applied onto the polarizing film so that the thickness was 1.0 ⁇ m, and ultraviolet rays were irradiated as an active energy ray to cure the adhesive. Ultraviolet irradiation is performed using a gallium-encapsulated metal halide lamp, irradiation device: Fusion UV Systems, Inc.
• HEAA N-hydroxyethylacrylamide
• ACMO acryloylmorpholine
• UVGACURE 819 photoinitiator
• Example 9 ⁇ Production of polarizing film and polarizing film>
• a polarizing film and a polarizing film were produced by the same operation as in Example 1 except that the ultraviolet curable adhesive described in Example 8 was used as the adhesive.
• Example 10> ⁇ Production of polarizing film and polarizing film>
• the iodine concentration of the polarizing film finally obtained in the dyeing bath step was adjusted to 4.48% by weight, and the washing bath was prepared with the nitro compound represented by the general formula (9).
• a compound having a nitroxy radical represented by the general formula (11) or a compound having a nitroxide group was added so that the concentration was 0.4% by weight,
• a polarizing film and a polarizing film were produced.
• the obtained polarizing film contained 0.22% by weight of the compound having a nitroxyl radical or a nitroxide group and had a thickness of 18 ⁇ m.
• the single transmittance of the polarizing film was 37.4%.
• Example 11 ⁇ Production of polarizing film and polarizing film>
• the iodine concentration of the polarizing film finally obtained in the dyeing bath step was adjusted to 4.67% by weight, and the concentration was adjusted to the stretching step bath and the washing step bath, respectively.
• a polarizing film and a polarizing film were prepared in the same manner as in Example 1, except that the compound having a nitroxy radical or a nitroxide group represented by the formula (9) was added so that the concentration was 0.4% by weight.
• the obtained polarizing film had a content of a compound having a nitroxy radical or a nitroxide group of 0.38% by weight and a thickness of 18 ⁇ m.
• the single transmittance of the polarizing film was 37.0%.
• Example 12> ⁇ Production of polarizing film and polarizing film>
• the iodine concentration of the polarizing film finally obtained in the dyeing bath step was adjusted to 4.42% by weight, and the washing step bath was represented by the general formula (8).
• a polarizing film and a polarizing film were produced in the same manner as in Example 1, except that the concentration of the compound having a nitroxyl radical or a nitroxide group was 0.3% by weight.
• the polarizing film thus obtained contained 0.10% by weight of a compound having a nitroxyl radical or a nitroxide group and had a thickness of 18 ⁇ m.
• the single transmittance of the polarizing film was 37.6%.
• polarizing film and polarizing film> ⁇ Production of polarizing film and polarizing film>
• the polarizing film and the polarizing film were prepared in the same manner as in Example 1 except that the washing bath was not added with the compound having the nitroxyl radical or the nitroxide group represented by the general formula (9).
• a film was made.
• the polarizing film obtained had a content of a compound having a nitroxyl radical or a nitroxide group of 0% by weight, an iodine content of 4.65% by weight, and a thickness of 18 ⁇ m.
• the single transmittance of the polarizing film was 37.1%.

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