WO2017204162A1 - Polarizing film, polarizing film with adhesive layer, and image display device - Google Patents
Polarizing film, polarizing film with adhesive layer, and image display device Download PDFInfo
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- WO2017204162A1 WO2017204162A1 PCT/JP2017/019030 JP2017019030W WO2017204162A1 WO 2017204162 A1 WO2017204162 A1 WO 2017204162A1 JP 2017019030 W JP2017019030 W JP 2017019030W WO 2017204162 A1 WO2017204162 A1 WO 2017204162A1
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- Prior art keywords
- film
- polarizer
- polarizing film
- resin film
- adhesive layer
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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
- G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
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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
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J7/00—Adhesives in the form of films or foils
- C09J7/20—Adhesives in the form of films or foils characterised by their carriers
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- 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
Definitions
- the present invention relates to a polarizing film and a polarizing film with an adhesive layer having the polarizing film and an adhesive layer. Moreover, this invention relates to the image display apparatus containing the said polarizing film with an adhesive layer.
- a polarizing film is used for image display.
- a liquid crystal display device LCD
- a circularly polarizing film in which a polarizing film and a quarter wavelength plate are laminated is disposed on the viewing side of the organic light emitting layer in order to shield the specular reflection of external light on the metal electrode.
- polarizing film generally, a polyvinyl alcohol film and a polarizer made of a dichroic material such as iodine are bonded to one or both surfaces with a protective film bonded with a polyvinyl alcohol adhesive or the like. ing.
- a polarizing film In a severe environment of thermal shock (for example, a heat shock test in which a temperature condition of ⁇ 40 ° C. and 85 ° C. is repeated), the polarizing film spreads along the absorption axis direction of the polarizer due to a change in the contraction stress of the polarizer. There is a problem that cracks (through cracks) are likely to occur. Therefore, in order to suppress the shrinkage of the polarizer and reduce the influence of thermal shock, a polarizing film usually has a 40 to 80 ⁇ m triacetyl cellulose (TAC) film as a protective film on both sides of the polarizer. A combined laminate is used. However, even in the polarizing film protected on both sides, the change in the shrinkage stress of the polarizer is not negligible, and it is difficult to completely suppress the influence of the shrinkage. It was inevitable that the shrinkage occurred.
- TAC triacetyl cellulose
- polarizers are also required to be thinner. If it is a thin polarizer with a thickness of 10 ⁇ m or less, the change in shrinkage stress is small, so that a through-crack is hardly generated.
- a polarizing film is disclosed in which a protective film is bonded to one or both sides of a thin polarizer having a thickness of 10 ⁇ m or less and generation of through cracks is suppressed (see, for example, Patent Document 1).
- the protective film is a double-sided protective polarizing film with both sides of a thin polarizer bonded
- the protective film provided on both sides can suppress the amount of shrinkage of the polarizer during the heat shock test. Can be effectively suppressed.
- a thin polarizer having a thickness of 10 ⁇ m or less has a problem that the optical characteristics in a humidified environment are likely to deteriorate. Therefore, even if it is a double-sided protective polarizing film using the said thin polarizer described in patent document 1, etc., depending on the kind of protective film, a polarizer deteriorates with a water
- the moisture permeability is extremely low (specifically, 30 g / (m 2 ⁇ day) or less as a protective film bonded to both surfaces of the thin polarizer).
- the use of a resin film is being studied.
- the polarizer can be prevented from degrading in a humidified environment, but a thin polarizer having a thickness of 10 ⁇ m or less is used.
- produces in a polarizing film was discovered, although the protective film was bonded together on both surfaces of the said thin polarizer.
- a polarizing film in which a resin film having extremely low moisture permeability is laminated on both surfaces of a polarizer having a thickness of 10 ⁇ m or less, the deterioration of the polarizer due to humidification is suppressed (humidification reliability), and thermal shock is prevented. It aims at providing the polarizing film which can suppress generation
- the present invention is a polarizing film having a first resin film on one surface of a polarizer having a thickness of 10 ⁇ m or less and a second resin film on the other surface,
- the moisture permeability of the first resin film and the second resin film are both 30 g / (m 2 ⁇ day) or less
- the present invention relates to a polarizing film comprising a protective plate on a surface of the first resin film opposite to the side having the polarizer.
- the linear expansion coefficient of the protective plate is preferably 1.0 ⁇ 10 ⁇ 5 / K or less in a direction orthogonal to the absorption axis of the polarizer.
- the linear expansion coefficients of the first resin film and the second resin film are 5.0 ⁇ 10 ⁇ 5 to 8.0 ⁇ 10 ⁇ 5 / K in the direction orthogonal to the absorption axis of the polarizer. preferable.
- the dimensional change rate when the first resin film and the second resin film are heated at 85 ° C. for 120 hours is ⁇ 0.40 to 0% in the direction perpendicular to the absorption axis of the polarizer. Is preferred.
- the breaking strength of the first resin film and the second resin film is preferably 5 to 30 N in the direction perpendicular to the absorption axis of the polarizer.
- the first resin film and the second resin film are preferably the same or different cycloolefin resin films.
- the absolute value of the degree of polarization change after being left in the environment for 500 hours is less than 0.1%.
- the present invention also relates to a polarizing film with a pressure-sensitive adhesive layer, characterized by having a pressure-sensitive adhesive layer on the second resin film side of the polarizing film.
- this invention relates to the image display apparatus characterized by having the said polarizing film with an adhesive layer.
- a resin film having a very low moisture permeability specifically, 30 g / (m 2 ⁇ day) or less
- the polarizer is deteriorated by humidification. It was newly found this time that through cracks are generated, although it is possible to suppress the humidity (improve humidification reliability).
- a resin film (protective film) with extremely low moisture permeability generally has a large linear expansion coefficient, a small dimensional change rate in the direction perpendicular to the absorption axis of the polarizer, and / or Or it is possible that the breaking strength is low.
- the breaking strength of the protective film is low in the direction perpendicular to the absorption axis of the polarizer, it is considered that the brittleness of the protective film is a trigger and penetration cracks are likely to occur in the polarizing film.
- the heat shock for example, a heat shock test in which a temperature condition of ⁇ 40 ° C. and 85 ° C. is repeated
- the amount of shrinkage of the entire polarizing film can be reduced, so that a protective film with extremely low moisture permeability on both sides of the polarizer (in other words, a linear expansion coefficient is large).
- the polarizing film of the present invention can achieve both suppression of polarizer deterioration by humidification (improvement of humidification reliability) and suppression of occurrence of through cracks.
- the present invention can provide a polarizing film with an adhesive layer that achieves both improved humidification reliability and suppression of the occurrence of through cracks, and an image display device using the polarizing film with the adhesive layer.
- the polarizing film of the present invention has a first resin film on one surface of a polarizer having a thickness of 10 ⁇ m or less, and a second resin film on the other surface, The moisture permeability of the first resin film and the second resin film are both 30 g / (m 2 ⁇ day) or less, The first resin film has a protective plate on the surface opposite to the side having the polarizer.
- the polarizing film 1 of the present invention has a first resin film 3 on one surface of a polarizer 2 and a second resin film 4 on the other surface. Further, a protective plate 5 is provided on the side of the first resin film 3 that does not have the polarizer 2.
- the first resin film 3 and the second resin film 4 can be bonded to the polarizer 2 through an adhesive layer (not shown).
- the protective plate 5 can be bonded to the first resin film 3 via an adhesive layer or an adhesive layer (not shown).
- the polarizing film 1 of this invention can contain layers (For example, an easily adhesive layer, various functional layers, etc.) other than the said layer.
- the first resin film 3 is preferably disposed on the viewing side of the polarizer 2, and the second resin film 4 is preferably disposed on the image display cell side of the polarizer 2.
- a thin polarizer having a thickness of 10 ⁇ m or less is used.
- the thickness of the polarizer is preferably 8 ⁇ m or less, more preferably 7 ⁇ m or less, and further preferably 6 ⁇ m or less from the viewpoint of reducing the thickness and preventing the occurrence of through cracks.
- the thickness of the polarizer is preferably 2 ⁇ m or more, and more preferably 3 ⁇ m or more.
- Such a thin polarizer has less thickness unevenness, excellent visibility, and less dimensional change, and therefore excellent durability against thermal shock.
- a polarizer using a polyvinyl alcohol resin is used.
- polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films.
- hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films.
- examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products.
- a polarizer composed of a polyvinyl alcohol film and a dichroic substance such as iodine is preferable.
- a polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol in an aqueous iodine solution and stretching it 3 to 7 times the original length. If necessary, it may contain boric acid, zinc sulfate, zinc chloride or the like, or may be immersed in an aqueous solution of potassium iodide or the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing.
- the polyvinyl alcohol film In addition to washing the polyvinyl alcohol film surface with stains and antiblocking agents by washing the polyvinyl alcohol film with water, the polyvinyl alcohol film is also swollen to prevent unevenness such as uneven coloring. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched even in an aqueous solution of boric acid or potassium iodide or in a water bath.
- the polarizer preferably contains boric acid from the viewpoint of stretching stability and humidification reliability.
- the boric acid content contained in the polarizer is preferably 22% by weight or less, more preferably 20% by weight or less, based on the total amount of the polarizer, from the viewpoint of suppressing the occurrence of through cracks.
- the boric acid content with respect to the total amount of the polarizer is preferably 10% by weight or more, and more preferably 12% by weight or more.
- the thin polarizer described in the publication 2014/077636 pamphlet etc. or the thin polarizer obtained from the manufacturing method as described in these can be mentioned.
- Patent No. 4751486, Patent in that it can be stretched at a high magnification and the polarization performance can be improved.
- stretching in a boric-acid aqueous solution as described in the 4751481 specification and the patent 4815544 specification is preferable, and it describes especially in the patent 4751481 specification and the patent 4815544 specification.
- stretching in the boric-acid aqueous solution which has this is preferable.
- These thin polarizers can be obtained by a production method including a step of stretching and dyeing a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin base material in a laminated state.
- PVA-based resin polyvinyl alcohol-based resin
- a stretching resin base material in a laminated state.
- 1st resin film As a material which forms the 1st resin film provided in one surface of the said polarizer, it has transparency and a water vapor transmission rate is 30 g / (m ⁇ 2 > * day) or less. Any material that can form a certain film may be used. Specific examples include a cycloolefin resin film.
- cycloolefin resin film a known film can be used without particular limitation as long as the moisture permeability is 30 g / (m 2 ⁇ day) or less.
- the cycloolefin-based resin is a general term for resins that are polymerized using a cycloolefin as a polymerization unit, and is described in, for example, JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, and the like. Resin.
- cycloolefin ring-opening (co) polymers examples include cycloolefin ring-opening (co) polymers, cycloolefin addition polymers, copolymers of cycloolefins with ⁇ -olefins such as ethylene and propylene (typically random copolymers), Examples thereof include graft polymers obtained by modifying these with unsaturated carboxylic acids or derivatives thereof, and hydrides thereof.
- Specific examples of the cycloolefin include norbornene monomers.
- cycloolefin resins Various products are commercially available as cycloolefin resins. Specific examples include trade names “ZEONEX” and “ZEONOR” manufactured by ZEON CORPORATION, trade names “ARTON” manufactured by JSR Corporation, “TOPASS” manufactured by TICONA, and products manufactured by Mitsui Chemicals, Inc. Product name “APEL” and the like.
- the moisture permeability of the first resin film is 30 g / (m 2 ⁇ day) or less, preferably 25 g / (m 2 ⁇ day) or less, and preferably 20 g / (m 2 ⁇ day) or less. More preferred. Further, the lower limit value of moisture permeability is not particularly limited, but ideally, it is preferable that water vapor is not permeated at all (that is, 0 g / (m 2 ⁇ day)). When the moisture permeability of the first resin film is in the above range, deterioration of the polarizer due to moisture can be suppressed.
- the thickness of the first resin film is not particularly limited, but is 10 ⁇ m or more from the viewpoint of lowering moisture permeability to increase humidification reliability and further increasing fracture strength to further suppress penetration cracks. It is preferable that it is 12 ⁇ m or more. On the other hand, from the viewpoint of thinning, it is preferably 40 ⁇ m or less, and more preferably 30 ⁇ m or less.
- the linear expansion coefficient of the first resin film is not particularly limited.
- 5.0 ⁇ 10 ⁇ 5 to 8.0 ⁇ 10 ⁇ 5 / K may be mentioned, and it may be about 5.5 ⁇ 10 ⁇ 5 to 7.5 ⁇ 10 ⁇ 5 / K.
- the polarizing film of the present invention can suppress the occurrence of through cracks even when the first resin film having extremely low moisture permeability and a linear expansion coefficient in the above range is used.
- a linear expansion coefficient it can measure with the measuring method as described in an Example.
- the breaking strength of the first resin film is not particularly limited.
- it in the direction perpendicular to the absorption axis of the polarizer, it can be about 5 to 30 N, and about 8 to 25 N. It may be about 8 to 23N.
- the polarizing film of this invention is a case where the 1st resin film which has very low moisture permeability and has the breaking strength of the said range is used, generation
- breaking strength it can measure by the measuring method as described in an Example.
- the dimensional change rate when the first resin film is heat-treated at 85 ° C. for 120 hours is not particularly limited.
- ⁇ 0 in the direction perpendicular to the absorption axis of the polarizer, ⁇ 0. It can be about 40 to 0%, can be about -0.34 to 0%, or can be about -0.33 to -0.01%.
- the polarizing film of the present invention can suppress the occurrence of through cracks even when the first resin film having extremely low moisture permeability and a dimensional change rate in the above range is used.
- About a dimensional change rate it can measure by the measuring method as described in an Example.
- the polarizer and the first resin film are usually in close contact with each other through an adhesive such as an active energy ray-curable adhesive from the viewpoint of humidification reliability.
- the active energy ray curable adhesive is an adhesive that cures by an active energy ray such as an electron beam or ultraviolet rays (radical curable type, cationic curable type), for example, in an electron beam curable type or an ultraviolet curable type. Can be used.
- an active energy ray curable adhesive for example, a photo radical curable adhesive can be used.
- the photo radical curable active energy ray curable adhesive is used as an ultraviolet curable adhesive, the adhesive contains a radical polymerizable compound and a photo polymerization initiator.
- the adhesive coating method is appropriately selected depending on the viscosity of the adhesive and the target thickness.
- coating methods include reverse coaters, gravure coaters (direct, reverse and offset), bar reverse coaters, roll coaters, die coaters, bar coaters, rod coaters and the like.
- a method such as a dapping method can be appropriately used.
- the surface of the first resin film to which the polarizer is not adhered may be subjected to a treatment for the purpose of hard coat layer, antireflection treatment, sticking prevention, diffusion or antiglare.
- the material for forming the second resin film may be any material that can form a film having transparency and moisture permeability of 30 g / (m 2 ⁇ day) or less. Specific examples include a cycloolefin resin film.
- Examples of the cycloolefin-based resin film include those listed for the first resin film.
- the moisture permeability of the second resin film is 30 g / (m 2 ⁇ day) or less, preferably 25 g / (m 2 ⁇ day) or less, and preferably 20 g / (m 2 ⁇ day) or less. More preferred. Further, the lower limit value of moisture permeability is not particularly limited, but ideally, it is preferable that water vapor is not permeated at all (that is, 0 g / (m 2 ⁇ day)). When the moisture permeability of the second resin film is within the above range, deterioration of the polarizer due to moisture can be suppressed.
- the thickness of the second resin film is not particularly limited, but is 10 ⁇ m or more from the viewpoint of lowering moisture permeability to increase humidification reliability and further increasing fracture strength to further suppress penetration cracks. It is preferable that it is 12 ⁇ m or more. On the other hand, from the viewpoint of thinning, it is preferably 40 ⁇ m or less, and more preferably 30 ⁇ m or less.
- the linear expansion coefficient of the second resin film is not particularly limited.
- 5.0 ⁇ 10 ⁇ 5 to 8.0 ⁇ 10 ⁇ 5 / K may be mentioned, and it may be about 5.5 ⁇ 10 ⁇ 5 to 7.5 ⁇ 10 ⁇ 5 / K.
- the polarizing film of the present invention can suppress the occurrence of through cracks even when the second resin film having extremely low moisture permeability and a linear expansion coefficient in the above range is used.
- a linear expansion coefficient it can measure with the measuring method as described in an Example.
- the breaking strength of the second resin film is not particularly limited.
- it in the direction perpendicular to the absorption axis of the polarizer, it can be about 5 to 30 N, and about 8 to 25 N. It may be about 8 to 23N.
- the polarizing film of the present invention can suppress the occurrence of through cracks even when a second resin film having extremely low moisture permeability and a breaking strength in the above range is used.
- breaking strength it can measure by the measuring method as described in an Example.
- the dimensional change rate when the second resin film is heat-treated at 85 ° C. for 120 hours is not particularly limited.
- ⁇ 0 in the direction perpendicular to the absorption axis of the polarizer, ⁇ 0. It can be about 40 to 0%, can be about -0.34 to 0%, or can be about -0.33 to -0.01%.
- the polarizing film of the present invention can suppress the occurrence of through cracks even when the second resin film having extremely low moisture permeability and a dimensional change rate in the above range is used.
- about a dimensional change rate it can measure by the measuring method as described in an Example.
- the polarizer and the second resin film are usually in close contact via an adhesive.
- the adhesive include those listed for the first resin film.
- the surface of the second resin film to which the polarizer is not adhered may be subjected to a treatment for the purpose of hard coat layer, antireflection treatment, sticking prevention, diffusion or antiglare.
- the polarizing film of the present invention has a protection plate on the side of the first resin film that does not have the polarizer.
- the protective plate is not particularly limited as long as it can suppress the shrinkage of the polarizing film even when the polarizing film of the present invention is exposed to a thermal shock environment.
- the linear expansion coefficient of the protective plate is preferably 1.0 ⁇ 10 ⁇ 5 / K or less in the direction perpendicular to the absorption axis of the polarizer, and is 9.0 ⁇ 10 ⁇ 6 / K or less. Is more preferably 8.0 ⁇ 10 ⁇ 6 / K or less.
- the protective plate can suppress the amount of contraction of the polarizer. Generation
- the lower limit value of the linear expansion coefficient is not particularly limited, but is preferably 1.0 ⁇ 10 ⁇ 6 / K or more, for example.
- the thickness of the protective plate is not particularly limited, but is preferably 0.5 to 1.0 mm, and more preferably 0.5 to 0.8 mm. It is preferable that the thickness of the protective plate is in the above range because the size does not easily shrink.
- the pencil hardness of the protective plate is preferably 8H or more, and more preferably 10H or more. Since the pencil hardness of the protective plate is in the above range, it is preferable because the size does not easily shrink.
- the pencil hardness is a pencil hardness according to JIS K 5600-5-4.
- the specific gravity of the protective plate is preferably 2.0 or more, and more preferably 2.3 or more. It is preferable that the specific gravity of the protective plate is in the above-mentioned range because it is difficult to shrink the dimensions.
- the thermal conductivity of the protective plate is preferably 2.0 W / (m ⁇ K) or less, and more preferably 1.5 W / (m ⁇ K) or less. Since the thermal conductivity of the protective plate is within the above range, heat is not easily transmitted to the polarizer even in a heat shock test, and the amount of contraction of the polarizer can be suppressed in a direction perpendicular to the absorption axis of the polarizer. Therefore, it is preferable.
- the material for forming the protective plate is not particularly limited, and examples thereof include glass and an acrylic plate. Among these, glass is preferable.
- the protective plate and the first resin film can be laminated via an adhesive layer or an adhesive layer.
- the adhesive layer the adhesive layer described in this specification can be used as appropriate.
- the pressure-sensitive adhesive layer is not particularly limited, and a known layer can be used.
- an adhesive layer specifically, for example, a (meth) acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based or a rubber-based polymer is used as a base polymer.
- acrylic pressure-sensitive adhesives based on (meth) acrylic polymers are excellent in optical transparency, exhibiting moderate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, weather resistance and heat resistance. Etc. are preferable.
- the (meth) acrylic polymer is not particularly limited, and can be obtained by polymerizing a monomer component containing an alkyl (meth) acrylate having an alkyl group having 4 to 24 carbon atoms at the terminal of the ester group. Can be mentioned.
- Alkyl (meth) acrylate refers to alkyl acrylate and / or alkyl methacrylate, and (meth) in the present invention has the same meaning.
- alkyl (meth) acrylate examples include those having a linear or branched alkyl group having 4 to 24 carbon atoms, and having a linear or branched alkyl group having 4 to 9 carbon atoms.
- Alkyl (meth) acrylates are preferred because they are easy to balance the adhesive properties. These alkyl (meth) acrylates can be used alone or in combination of two or more.
- the monomer component forming the (meth) acrylic polymer can contain a copolymerizable monomer other than the alkyl (meth) acrylate as a monofunctional monomer component.
- copolymerizable monomers include cyclic nitrogen-containing monomers, hydroxyl group-containing monomers, carboxyl group-containing monomers, and monomers having a cyclic ether group.
- the monomer component forming the (meth) acrylic polymer can contain a polyfunctional monomer as necessary in order to adjust the cohesive force of the pressure-sensitive adhesive.
- the polyfunctional monomer is a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, such as dipentaerythritol hexa (meth) acrylate, 1 , 6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate.
- a polyfunctional monomer can be used individually by 1 type or in combination of 2 or more types.
- the production of such a (meth) acrylic polymer can be appropriately selected from known production methods such as radiation polymerization such as solution polymerization and ultraviolet polymerization, various radical polymerizations such as bulk polymerization and emulsion polymerization. Further, the (meth) acrylic polymer obtained may be a random copolymer, a block copolymer, a graft copolymer or the like.
- the polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited, and known ones commonly used in this field can be appropriately selected and used.
- the weight average molecular weight of the (meth) acrylic polymer can be controlled by the amount of polymerization initiator, the amount of chain transfer agent used, and the reaction conditions, and the amount used is appropriately adjusted according to these types.
- the weight average molecular weight of the (meth) acrylic polymer used in the present invention is preferably 400,000 to 4,000,000. By making the weight average molecular weight larger than 400,000, it is possible to satisfy the durability of the pressure-sensitive adhesive layer, or to suppress the occurrence of adhesive residue due to the reduced cohesive force of the pressure-sensitive adhesive layer. On the other hand, when the weight average molecular weight is larger than 4 million, the bonding property tends to be lowered. Furthermore, in the solution system, the viscosity becomes too high, and coating may be difficult.
- the weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene. In addition, it is difficult to measure the molecular weight of the (meth) acrylic polymer obtained by radiation polymerization.
- the pressure-sensitive adhesive composition used in the present invention can contain a crosslinking agent.
- crosslinking agents include isocyanate crosslinking agents, epoxy crosslinking agents, silicone crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, silane crosslinking agents, alkyletherified melamine crosslinking agents, metal chelate crosslinking agents,
- the crosslinking agent include oxides, and these can be used alone or in combination of two or more.
- an isocyanate type crosslinking agent and an epoxy-type crosslinking agent are used preferably.
- the crosslinking agent may be used alone or in combination of two or more, but the total content is based on 100 parts by weight of the (meth) acrylic polymer.
- the crosslinking agent is preferably contained in the range of 0.01 to 10 parts by weight.
- a (meth) acrylic oligomer can be contained in order to improve the adhesive force.
- the pressure-sensitive adhesive composition used in the present invention may contain a silane coupling agent in order to increase the water resistance at the interface when applied to a hydrophilic adherend such as glass of the pressure-sensitive adhesive layer.
- the pressure-sensitive adhesive composition used in the present invention may contain other known additives, such as polyether compounds of polyalkylene glycols such as polypropylene glycol, powders of colorants and pigments, dyes, and the like. , Surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, UV absorbers, polymerization inhibitors, inorganic or organic fillers, It can be added as appropriate depending on the application in which metal powder, particles, foil, etc. are used. Moreover, you may employ
- the formation method of the pressure-sensitive adhesive layer can be performed by a known method.
- an adhesive layer for laminating the protective plate and the first resin film “LUCIACS” manufactured by Nitto Denko Corporation, “Clear Fit” manufactured by Mitsubishi Plastics Co., Ltd., manufactured by Dexerials Corporation
- a pressure-sensitive adhesive layer pressure-sensitive adhesive sheet
- SVR optical elastic resin
- the absolute value of the degree of polarization change after standing in the environment for 500 hours is preferably less than 0.1%, more preferably 0.05% or less, and further preferably 0.03% or less. preferable. Since the polarizing film of the present invention has a protective plate laminated on the first resin film, it can be used in a severe environment of thermal shock (for example, a heat shock test in which temperature conditions of ⁇ 40 ° C. and 85 ° C. are repeated).
- the shrinkage force of the polarizing film as a whole becomes extremely small, and furthermore, since the low moisture permeation protective film is used, the deterioration of the polarizer due to water is suppressed, and as a result, even when exposed to harsh environments, the degree of polarization The change is small and the optical characteristics are excellent.
- the polarizing film with an adhesive layer of this invention has an adhesive layer in the said 2nd resin film side of the said polarizing film, It is characterized by the above-mentioned.
- the pressure-sensitive adhesive layer can be laminated on the side having no polarizer of the second resin film.
- the polarizing film 10 with the pressure-sensitive adhesive layer of the present invention comprises a protective plate 5, a first resin film 3, a polarizer 2, a second resin film 4, and a pressure-sensitive adhesive layer 6. In order.
- the polarizing film with the pressure-sensitive adhesive layer of the present invention is obtained by directly applying the pressure-sensitive adhesive composition on the second resin film of the polarizing film having the protective plate, and removing the solvent and the like by heating and drying. Can be formed. Moreover, the adhesive layer formed in the support body etc. can be transcribe
- the pressure-sensitive adhesive composition those described in the present specification can be appropriately used, and among them, an acrylic pressure-sensitive adhesive having the above-mentioned (meth) acrylic polymer as a base polymer is preferable.
- Various methods are used as a method for applying the pressure-sensitive adhesive composition. Specifically, for example, by roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples thereof include an extrusion coating method.
- the heating and drying temperature is preferably about 30 to 200 ° C, more preferably about 40 to 180 ° C, and further preferably about 80 to 150 ° C. By setting the heating temperature in the above range, an adhesive layer having excellent adhesive properties can be obtained.
- As the drying time an appropriate time can be adopted as appropriate.
- the drying time is preferably about 5 seconds to 20 minutes, more preferably about 30 seconds to 10 minutes, and further preferably 1 minute to 8 minutes.
- a peeled sheet for example, a peeled sheet (separator) can be used.
- a silicone release liner is preferably used as the release-treated sheet.
- constituent material of the separator examples include, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and laminates thereof.
- plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films
- porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and laminates thereof.
- a plastic film is used suitably from the point which is excellent in surface smoothness.
- plastic film examples include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene.
- plastic film examples include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene.
- -Vinyl acetate copolymer film and the like.
- the thickness of the separator is usually about 5 to 200 ⁇ m, preferably about 5 to 100 ⁇ m.
- An antistatic treatment such as a mold can also be performed.
- the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the separator.
- seat which carried out the peeling process used in preparation of said polarizing film with an adhesive layer can be used as a separator of the polarizing film with an adhesive layer as it is, and can simplify in a process surface.
- the pressure-sensitive adhesive layer is formed after an anchor layer is formed on the surface of the second resin film, or after various easy adhesion treatments such as corona treatment and plasma treatment.
- An agent layer can be formed. Moreover, you may perform an easily bonding process on the surface of an adhesive layer.
- the thickness of the pressure-sensitive adhesive layer is not particularly limited, and is preferably 5 to 100 ⁇ m, for example, and preferably 10 to 50 ⁇ m.
- the polarizing film with the pressure-sensitive adhesive layer of the present invention uses a double-sided protective polarizing film with a polarizer thickness of 10 ⁇ m or less, the polarizing film with the pressure-sensitive adhesive layer as a whole can be thinned.
- the thickness of the polarizing film with the pressure-sensitive adhesive layer can be 70 ⁇ m or less.
- the polarizing film with an adhesive layer of the present invention can be attached to an image display cell such as a liquid crystal cell through the adhesive layer.
- the polarizing film with an adhesive layer of this invention can be used suitably as a visual recognition side polarizing film of a liquid crystal display device.
- Image display device The image display device of the present invention has the above-mentioned polarizing film with an adhesive layer.
- the image display device of the present invention only needs to include the polarizing film with the pressure-sensitive adhesive layer of the present invention, and other configurations can be the same as those of the conventional image display device.
- the image display device of the present invention includes the polarizing film with the pressure-sensitive adhesive layer, it has high reliability.
- the laminate was immersed in an insolubilization bath (a boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with respect to 100 parts by weight of water) for 30 seconds (insolubilization treatment). Subsequently, it was immersed in a dyeing bath having a liquid temperature of 30 ° C. while adjusting the iodine concentration and the immersion time so that the polarizing plate had a predetermined transmittance.
- 0.2 parts by weight of iodine was blended with 100 parts by weight of water, and immersed in an aqueous iodine solution obtained by blending 1.0 part by weight of potassium iodide (dyeing treatment). .
- a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with respect to 100 parts by weight of water was immersed for 30 seconds in a crosslinking bath having a liquid temperature of 30 ° C.
- a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with respect to 100 parts by weight of water (Crosslinking treatment).
- the laminated body was added to a boric acid aqueous solution having a liquid temperature of 70 ° C. (an aqueous solution obtained by adding 4.5 parts by weight of boric acid and 5 parts by weight of potassium iodide to 100 parts by weight of water).
- An ultraviolet curable 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).
- HEAA N-hydroxyethylacrylamide
- ACMO acryloylmorpholine
- UVGACURE 819 a photoinitiator
- the viewing-side transparent protective film First resin film (Cycloolefin film having a thickness of 27 ⁇ m (trade name: ZF12-025-1300UHC, manufactured by Nippon Zeon Co., Ltd.), moisture permeability at 40 ° C., 92% RH: 17 g / (m 2 ⁇ day), linear expansion coefficient: 6 ⁇ 10 ⁇ 5 / K, dimensional change rate: ⁇ 0.33%, breaking strength: 13 N), and then irradiated with ultraviolet rays as active energy rays, adhesive was cured.
- First resin film Cycloolefin film having a thickness of 27 ⁇ m (trade name: ZF12-025-1300UHC, manufactured by Nippon Zeon Co., Ltd.)
- linear expansion coefficient 6 ⁇ 10 ⁇ 5 / K
- dimensional change rate ⁇ 0.33%
- breaking strength 13 N
- Ultraviolet irradiation is performed using a gallium-encapsulated metal halide lamp, an irradiation device: Fusion UV Systems, Inc.
- the illuminance of ultraviolet rays was measured using a Sola-Check system manufactured by Solatell.
- the amorphous PET base material is peeled off, and the UV curable adhesive is applied to the peeled surface so that the thickness of the adhesive layer after curing is 0.1 ⁇ m, and corona treatment in advance.
- Image display cell side transparent protective film (second resin film) (cycloolefin film having a thickness of 13 ⁇ m (trade name: ZF-014-1330, manufactured by Nippon Zeon Co., Ltd.), 40 ° C., 92% RH
- the moisture permeability is 12 g / (m 2 ⁇ day)
- the coefficient of linear expansion is 7.1 ⁇ 10 ⁇ 5 / K
- the dimensional change rate is ⁇ 0.01%
- the breaking strength is 9 N.
- ultraviolet rays were irradiated to cure the adhesive, and a double-sided protective polarizing film (1) using a thin polarizer was produced.
- UV irradiation is performed using a gallium-filled metal halide lamp, irradiation device: Fusion UVSystems, Inc.
- the illuminance of ultraviolet rays was measured using a Sola-Check system manufactured by Solatell.
- the amorphous PET base material is peeled off, and the UV curable adhesive produced in Example 1 is applied to the peeled surface so that the thickness of the cured adhesive layer is 0.1 ⁇ m.
- Image display cell side transparent protective film (cycloolefin film having a thickness of 13 ⁇ m (trade name: ZF-014-1330, manufactured by Nippon Zeon Co., Ltd.), moisture permeability at 40 ° C., 92% RH: 12 g / (M 2 ⁇ day), linear expansion coefficient: 7.1 ⁇ 10 ⁇ 5 / K, dimensional change rate: ⁇ 0.01%, breaking strength: 9 N), and then irradiated with ultraviolet rays in the same manner as above.
- the adhesive was cured to prepare a double-sided protective polarizing film (2) using a thin polarizer.
- Production Example 3 (Production of Polarizing Film (3)) While applying a polyvinyl alcohol-based adhesive on the surface of the polarizer (thickness: 5 ⁇ m) of the optical film laminate obtained in Production Example 1 so that the thickness of the adhesive layer is 0.1 ⁇ m, the viewing side is transparent.
- Protective film (Acrylic film having a thickness of 40 ⁇ m (trade name: HX-40UC-1330, manufactured by Kaneka Corporation), moisture permeability at 40 ° C., 92% RH: 70 g / (m 2 ⁇ day), wire (Expansion coefficient: 4.3 ⁇ 10 ⁇ 5 / K, dimensional change rate: ⁇ 0.5%, breaking strength: 39 N), and then drying at 50 ° C. for 5 minutes.
- the amorphous PET base material was peeled off, and the image display cell side transparent protective film (with the polyvinyl alcohol adhesive applied to the peeled surface so that the thickness of the adhesive layer was 0.1 ⁇ m
- Acrylic film having a thickness of 20 ⁇ m (trade name: RV-20UB-1330, manufactured by Toyo Kohan Co., Ltd.), moisture permeability at 40 ° C. and 92% RH: 170 g / (m 2 ⁇ day), linear expansion
- the coefficient 5.6 ⁇ 10 ⁇ 5 / K, dimensional change rate: ⁇ 0.35%, breaking strength: 19 N
- a protective polarizing film (3) was produced.
- Example 1 On the viewing-side protective film of the double-sided protective polarizing film (1) obtained in Production Example 1, an adhesive sheet (thickness: 150 ⁇ m, “LUCIACS” (trade name), which is an adhesive sheet manufactured by Nitto Denko Corporation) To form a pressure-sensitive adhesive layer, and a protective plate (500 ⁇ m thick cover glass, linear expansion coefficient: 8 ⁇ 10 ⁇ 6 / K, pencil hardness: 10H, specific gravity: 2.5, Thermal conductivity: 1 W / (m ⁇ K)) was laminated to form a polarizing film with a protective plate.
- an adhesive sheet thickness: 150 ⁇ m, “LUCIACS” (trade name), which is an adhesive sheet manufactured by Nitto Denko Corporation
- a protective plate 500 ⁇ m thick cover glass, linear expansion coefficient: 8 ⁇ 10 ⁇ 6 / K, pencil hardness: 10H, specific gravity: 2.5, Thermal conductivity: 1 W / (m ⁇ K)
- Example 2 A polarizing film with a protective plate was formed in the same manner as in Example 1 except that the double-sided protective polarizing film (2) obtained in Production Example 2 was used.
- Comparative Examples 1 to 3 In Comparative Examples 1 to 3, the double-sided protective polarizing films (1) to (3) obtained in Production Examples 1 to 3 were used as they were (no protective plate was laminated).
- Example moisture permeability of protective film used in comparative example, linear expansion coefficient of protective film and protective plate, polarizing film with protective film obtained in example, dimensional change rate of polarizing film used in comparative example, and penetration
- the occurrence of cracks was measured by the following method.
- the moisture permeability was measured according to a moisture permeability test (cup method) of JIS Z0208. A sample cut to a diameter of 6 cm was set in a moisture permeable cup (opening diameter: diameter 6 cm) containing about 15 g of calcium chloride, and the temperature was 40 ° C. and the humidity was 92% R.D. H. The moisture permeability (g / (m 2 ⁇ day)) was determined by measuring the weight increase of calcium chloride before and after being left for 24 hours.
- a sample was prepared by cutting the double-sided protective polarizing film used in Examples and Comparative Examples into a size of 100 mm ⁇ 100 mm (absorption axis direction of polarizer is 100 mm). The sample was autoclaved at 50 ° C. and 0.5 MPa for 15 minutes, removed from the autoclave, and allowed to stand for 24 hours in an environment at room temperature (23 ° C.). Thereafter, it was put into an oven at 85 ° C. for 120 hours.
- the protective film After taking out from the oven, the protective film is peeled off from the sample, and for each protective film, the length of each protective film is measured using a non-contact type two-dimensional image analyzer (trade name: QVA606L1L-C, manufactured by Mitutoyo Corporation). Was measured. From the measured values before and after the treatment, the dimensional change rate was calculated based on the following formula.
- the linear expansion coefficient was measured using a thermomechanical analyzer (product name: TMA7100, manufactured by Hitachi High-Tech Science Co., Ltd.). Specifically, a sample (length 20 mm ⁇ width 5 mm) was cut out from the protective film used in Examples and Comparative Examples, the sample was set in a tensile measurement jig, a tensile load 20 mN, a temperature increase rate, 10 ° C./min. The linear expansion coefficient was obtained by measuring -40 ° C to 85 ° C under the conditions of 4 cycles (heat shock conditions). The linear expansion coefficient was measured in a direction perpendicular to the absorption axis of the polarizer.
- ⁇ Measurement of change in polarization degree ( ⁇ P) of polarizing film The polarizing films obtained in Examples and Comparative Examples were subjected to 85 ° C./85% R.D. H. For 500 hours.
- the polarization degree of the polarizing film before and after the addition was measured using a spectrophotometer with an integrating sphere (V7100 manufactured by JASCO Corporation), and the amount of change ⁇ P in the polarization degree was determined by the following equation.
- Polarization degree P (%) ⁇ (Tp ⁇ Tc) / (Tp + Tc) ⁇ 1/2 ⁇ 100
- Each transmittance is represented by a Y value obtained by correcting visibility with a two-degree field of view (C light source) of JIS Z8701, with 100% of the completely polarized light obtained through the Granteller prism polarizer.
- heat shock test> A pressure-sensitive adhesive layer was provided on the image display cell side transparent protective film side of the double-sided protective polarizing film obtained in Examples and Comparative Examples to prepare a polarizing film with a pressure-sensitive adhesive layer.
- the polarizing film with a pressure-sensitive adhesive layer was cut into 50 mm ⁇ 150 mm (absorption axis direction was 50 mm), and bonded to 0.5 mm-thick alkali-free glass to prepare a sample.
- the sample was subjected to a heat shock of ⁇ 40 to 85 ° C. for 30 minutes ⁇ 100 times in each environment, and then taken out, and it was visually confirmed whether or not there were through cracks (number) in the polarizing film. . This test was performed 10 times.
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Abstract
Description
本発明は、偏光フィルム、及び当該偏光フィルムと粘着剤層を有する粘着剤層付き偏光フィルムに関する。また、本発明は、前記粘着剤層付き偏光フィルムを含む画像表示装置に関する。 The present invention relates to a polarizing film and a polarizing film with an adhesive layer having the polarizing film and an adhesive layer. Moreover, this invention relates to the image display apparatus containing the said polarizing film with an adhesive layer.
各種画像表示装置においては、画像表示のために偏光フィルムが用いられている。例えば、液晶表示装置(LCD)は、その画像形成方式から液晶パネル表面を形成するガラス基板の両側に偏光フィルムを配置することが必要不可欠である。また、有機EL表示装置では、金属電極での外光の鏡面反射を遮蔽するために、有機発光層の視認側に、偏光フィルムと1/4波長板を積層した円偏光フィルムが配置される。 In various image display devices, a polarizing film is used for image display. For example, in a liquid crystal display device (LCD), it is indispensable to dispose polarizing films on both sides of a glass substrate on which a liquid crystal panel surface is formed because of its image forming method. Further, in the organic EL display device, a circularly polarizing film in which a polarizing film and a quarter wavelength plate are laminated is disposed on the viewing side of the organic light emitting layer in order to shield the specular reflection of external light on the metal electrode.
前記偏光フィルムとしては、一般的には、ポリビニルアルコール系フィルムとヨウ素等の二色性材料からなる偏光子の片面又は両面に、保護フィルムをポリビニルアルコール系接着剤等により貼り合わせたものが用いられている。 As the polarizing film, generally, a polyvinyl alcohol film and a polarizer made of a dichroic material such as iodine are bonded to one or both surfaces with a protective film bonded with a polyvinyl alcohol adhesive or the like. ing.
前記偏光フィルムは、熱衝撃(例えば、-40℃と85℃の温度条件を繰り返すヒートショック試験)の過酷な環境下では、偏光子の収縮応力の変化によって、偏光子の吸収軸方向の全体にクラック(貫通クラック)が生じやすいという問題がある。従って、偏光子の収縮を抑制し、熱衝撃の影響を軽減するために、通常、偏光フィルムは、偏光子の両面に、保護フィルムとして、40~80μmのトリアセチルセルロース系(TAC)フィルムが貼り合された積層体が用いられる。しかしながら、前記両面保護された偏光フィルムであっても、偏光子の収縮応力の変化は無視できず、収縮の影響を完全に抑制することは困難であり、偏光子を含む光学フィルム積層体にある程度の収縮を生じるのは避けられなかった。 In a severe environment of thermal shock (for example, a heat shock test in which a temperature condition of −40 ° C. and 85 ° C. is repeated), the polarizing film spreads along the absorption axis direction of the polarizer due to a change in the contraction stress of the polarizer. There is a problem that cracks (through cracks) are likely to occur. Therefore, in order to suppress the shrinkage of the polarizer and reduce the influence of thermal shock, a polarizing film usually has a 40 to 80 μm triacetyl cellulose (TAC) film as a protective film on both sides of the polarizer. A combined laminate is used. However, even in the polarizing film protected on both sides, the change in the shrinkage stress of the polarizer is not negligible, and it is difficult to completely suppress the influence of the shrinkage. It was inevitable that the shrinkage occurred.
一方、近年、液晶表示装置等の画像表示装置の薄型化が進み、それに伴い、偏光子にも薄型化が求められている。厚み10μm以下の薄型偏光子であれば、収縮応力の変化が小さいため、貫通クラックは発生しにくくなる。例えば、厚み10μm以下の薄型偏光子の片面又は両面に保護フィルムが貼り合せられ、貫通クラックの発生が抑制された偏光フィルムが開示されている(例えば、特許文献1参照)。特に、薄型偏光子の両面に保護フィルムが貼り合せられた両面保護偏光フィルムであれば、両側に設けられた保護フィルムによって、ヒートショック試験時に偏光子の収縮量を抑えることができるため、貫通クラックを効果的に抑制することができる。 On the other hand, in recent years, image display devices such as liquid crystal display devices have become thinner, and accordingly, polarizers are also required to be thinner. If it is a thin polarizer with a thickness of 10 μm or less, the change in shrinkage stress is small, so that a through-crack is hardly generated. For example, a polarizing film is disclosed in which a protective film is bonded to one or both sides of a thin polarizer having a thickness of 10 μm or less and generation of through cracks is suppressed (see, for example, Patent Document 1). In particular, if the protective film is a double-sided protective polarizing film with both sides of a thin polarizer bonded, the protective film provided on both sides can suppress the amount of shrinkage of the polarizer during the heat shock test. Can be effectively suppressed.
しかしながら、一方で、厚み10μm以下の薄型偏光子は、加湿環境下での光学特性が低下しやすいという問題がある。よって、特許文献1等に記載された前記薄型偏光子を用いた両面保護偏光フィルムであっても、保護フィルムの種類によっては、加湿環境下において偏光子が水分によって劣化し、偏光フィルムの光学特性が著しく低下してしまう。
However, on the other hand, a thin polarizer having a thickness of 10 μm or less has a problem that the optical characteristics in a humidified environment are likely to deteriorate. Therefore, even if it is a double-sided protective polarizing film using the said thin polarizer described in
そこで、このような水分による偏光子の劣化を抑制する目的で、薄型偏光子の両面に貼り合わされる保護フィルムとして、透湿度が極めて低い(具体的には、30g/(m2・day)以下の)樹脂フィルムを使用することが検討されている。しかしながら、このような透湿度が極めて低い樹脂フィルムを保護フィルムとして使用した場合には、加湿環境下における偏光子の劣化は抑制することができるものの、厚さ10μm以下の薄型偏光子を用いており、かつ当該薄型偏光子の両面に保護フィルムが貼り合わされているにも関わらず、偏光フィルムに貫通クラックが発生するという、新たな課題が見つかった。 Therefore, in order to suppress the deterioration of the polarizer due to such moisture, the moisture permeability is extremely low (specifically, 30 g / (m 2 · day) or less as a protective film bonded to both surfaces of the thin polarizer). The use of a resin film is being studied. However, when such a resin film having extremely low moisture permeability is used as a protective film, the polarizer can be prevented from degrading in a humidified environment, but a thin polarizer having a thickness of 10 μm or less is used. And the new subject that a penetration crack generate | occur | produces in a polarizing film was discovered, although the protective film was bonded together on both surfaces of the said thin polarizer.
そこで、本発明においては、厚さ10μm以下の偏光子の両面に透湿度が極めて低い樹脂フィルムを積層した偏光フィルムにおいて、加湿による偏光子の劣化を抑え(加湿信頼性)、かつ、熱衝撃の過酷な環境下においても貫通クラックの発生を抑制することができる偏光フィルムを提供することを目的とする。 Therefore, in the present invention, in a polarizing film in which a resin film having extremely low moisture permeability is laminated on both surfaces of a polarizer having a thickness of 10 μm or less, the deterioration of the polarizer due to humidification is suppressed (humidification reliability), and thermal shock is prevented. It aims at providing the polarizing film which can suppress generation | occurrence | production of a penetration crack even in a severe environment.
本発明者らは前記課題を解決すべく鋭意検討を重ねた結果、下記偏光フィルムを見出し、本発明を完成するに至った。 As a result of intensive studies to solve the above problems, the present inventors have found the following polarizing film and have completed the present invention.
すなわち、本発明は、厚みが10μm以下の偏光子の一方の面に第1樹脂フィルム、他方の面に第2樹脂フィルムを有する偏光フィルムであって、
前記第1樹脂フィルム及び第2樹脂フィルムの透湿度が、いずれも30g/(m2・day)以下であり、
前記第1樹脂フィルムの前記偏光子を有する側とは反対側の面に保護板を有することを特徴とする偏光フィルムに関する。
That is, the present invention is a polarizing film having a first resin film on one surface of a polarizer having a thickness of 10 μm or less and a second resin film on the other surface,
The moisture permeability of the first resin film and the second resin film are both 30 g / (m 2 · day) or less,
The present invention relates to a polarizing film comprising a protective plate on a surface of the first resin film opposite to the side having the polarizer.
前記保護板の線膨張係数が、前記偏光子の吸収軸に直交する方向において、1.0×10-5/K以下であることが好ましい。 The linear expansion coefficient of the protective plate is preferably 1.0 × 10 −5 / K or less in a direction orthogonal to the absorption axis of the polarizer.
前記第1樹脂フィルム及び前記第2樹脂フィルムの線膨張係数は、前記偏光子の吸収軸に直交する方向において、5.0×10-5~8.0×10-5/Kであることが好ましい。 The linear expansion coefficients of the first resin film and the second resin film are 5.0 × 10 −5 to 8.0 × 10 −5 / K in the direction orthogonal to the absorption axis of the polarizer. preferable.
前記第1樹脂フィルム及び前記第2樹脂フィルムの85℃で120時間の加熱処理した際の寸法変化率が、前記偏光子の吸収軸に直交する方向において、-0.40~0%であることが好ましい。 The dimensional change rate when the first resin film and the second resin film are heated at 85 ° C. for 120 hours is −0.40 to 0% in the direction perpendicular to the absorption axis of the polarizer. Is preferred.
前記第1樹脂フィルム及び前記第2樹脂フィルムの破断強度は、前記偏光子の吸収軸に直交する方向において、5~30Nであることが好ましい。 The breaking strength of the first resin film and the second resin film is preferably 5 to 30 N in the direction perpendicular to the absorption axis of the polarizer.
前記第1樹脂フィルム及び前記第2樹脂フィルムは、同一又は異なるシクロオレフィン系樹脂フィルムであることが好ましい。 The first resin film and the second resin film are preferably the same or different cycloolefin resin films.
85℃、85%R.H.環境下に500時間放置後の偏光度変化率の絶対値が、0.1%未満であることが好ましい。 85 ° C, 85% R.V. H. It is preferable that the absolute value of the degree of polarization change after being left in the environment for 500 hours is less than 0.1%.
また、本発明は、前記偏光フィルムの前記第2樹脂フィルム側に粘着剤層を有することを特徴とする粘着剤層付き偏光フィルムに関する。 The present invention also relates to a polarizing film with a pressure-sensitive adhesive layer, characterized by having a pressure-sensitive adhesive layer on the second resin film side of the polarizing film.
さらに、本発明は、前記粘着剤層付き偏光フィルムを有することを特徴とする画像表示装置に関する。 Furthermore, this invention relates to the image display apparatus characterized by having the said polarizing film with an adhesive layer.
前述の通り、薄型偏光子の両面に透湿度が極めて低い樹脂フィルム(具体的には、30g/(m2・day)以下の)を保護フィルムとして積層した偏光フィルムでは、加湿による偏光子の劣化を抑制できる(加湿信頼性を向上できる)ものの、貫通クラックが発生することが今回新たに分かった。貫通クラックが発生する要因としては、透湿度が極めて低い樹脂フィルム(保護フィルム)は、一般的に前記偏光子の吸収軸に直交する方向において線膨張係数が大きく、寸法変化率が小さく、及び/又は、破断強度が低いことが考えられる。前記偏光子の吸収軸に直交する方向において、保護フィルムの線膨張係数が大きいと、ヒートショック試験における膨張と収縮の差が大きくなるため、歪みが大きくなり、結果として、偏光フィルムに貫通クラックが発生しやすくなると考えられる。また、前記偏光子の吸収軸に直交する方向において、保護フィルムの寸法変化率が小さいと、ヒートショック試験における冷却時において偏光子の収縮に保護フィルムが追従しにくいため、応力がたまり、その結果、偏光フィルムに貫通クラックが発生しやすくなると考えられる。さらに、前記偏光子の吸収軸に直交する方向において、保護フィルムの破断強度が低いと、保護フィルムの脆さがきっかけとなり、偏光フィルムに貫通クラックが発生しやすくなると考えられる。 As described above, in a polarizing film in which a resin film having a very low moisture permeability (specifically, 30 g / (m 2 · day) or less) is laminated on both surfaces of a thin polarizer as a protective film, the polarizer is deteriorated by humidification. It was newly found this time that through cracks are generated, although it is possible to suppress the humidity (improve humidification reliability). As a cause of the occurrence of through cracks, a resin film (protective film) with extremely low moisture permeability generally has a large linear expansion coefficient, a small dimensional change rate in the direction perpendicular to the absorption axis of the polarizer, and / or Or it is possible that the breaking strength is low. In the direction perpendicular to the absorption axis of the polarizer, if the linear expansion coefficient of the protective film is large, the difference between expansion and contraction in the heat shock test increases, resulting in increased distortion, and as a result, there are through cracks in the polarizing film. This is likely to occur. In addition, if the dimensional change rate of the protective film is small in the direction orthogonal to the absorption axis of the polarizer, the protective film hardly follows the contraction of the polarizer during cooling in the heat shock test, so stress accumulates, and as a result It is considered that through cracks are likely to occur in the polarizing film. Furthermore, if the breaking strength of the protective film is low in the direction perpendicular to the absorption axis of the polarizer, it is considered that the brittleness of the protective film is a trigger and penetration cracks are likely to occur in the polarizing film.
本発明においては、前記偏光フィルムの第1樹脂フィルム上に保護板を貼り合せているため、熱衝撃(例えば、-40℃と85℃の温度条件を繰り返すヒートショック試験)の過酷な環境下においても、前記偏光子の吸収軸に直交する方向において、偏光フィルム全体としての収縮量を小さくすることができるため、偏光子の両面に透湿度が極めて低い保護フィルム(いいかえれば、線膨張係数が大きく、寸法変化率が小さく、及び/又は、破断強度が低い保護フィルム)を積層しても、偏光フィルムに貫通クラックが発生することを抑制することができるものである。すなわち、本発明の偏光フィルムは、加湿による偏光子の劣化抑制(加湿信頼性の向上)と貫通クラックの発生抑制を両立することができる。 In the present invention, since a protective plate is bonded to the first resin film of the polarizing film, the heat shock (for example, a heat shock test in which a temperature condition of −40 ° C. and 85 ° C. is repeated) is used in a severe environment. However, in the direction orthogonal to the absorption axis of the polarizer, the amount of shrinkage of the entire polarizing film can be reduced, so that a protective film with extremely low moisture permeability on both sides of the polarizer (in other words, a linear expansion coefficient is large). Even when a protective film having a small dimensional change rate and / or low breaking strength is laminated, it is possible to suppress the occurrence of through cracks in the polarizing film. That is, the polarizing film of the present invention can achieve both suppression of polarizer deterioration by humidification (improvement of humidification reliability) and suppression of occurrence of through cracks.
また、本発明は、加湿信頼性の向上と貫通クラックの発生抑制を両立した粘着剤層付き偏光フィルム、及び、当該粘着剤層付き偏光フィルムを用いた画像表示装置を提供することができる。 Moreover, the present invention can provide a polarizing film with an adhesive layer that achieves both improved humidification reliability and suppression of the occurrence of through cracks, and an image display device using the polarizing film with the adhesive layer.
1.偏光フィルム
本発明の偏光フィルムは、厚みが10μm以下の偏光子の一方の面に第1樹脂フィルム、他方の面に第2樹脂フィルムを有し、
前記第1樹脂フィルム及び第2樹脂フィルムの透湿度が、いずれも30g/(m2・day)以下であり、
前記第1樹脂フィルムの前記偏光子を有する側とは反対側の面に保護板を有することを特徴とする。
1. Polarizing film The polarizing film of the present invention has a first resin film on one surface of a polarizer having a thickness of 10 μm or less, and a second resin film on the other surface,
The moisture permeability of the first resin film and the second resin film are both 30 g / (m 2 · day) or less,
The first resin film has a protective plate on the surface opposite to the side having the polarizer.
本発明においては、前述の通り、前記偏光フィルムの第1樹脂フィルム上に保護板を貼り合せているため、熱衝撃(例えば、-40℃と85℃の温度条件を繰り返すヒートショック試験)の過酷な環境下や、加湿環境下においても、前記偏光子の吸収軸に直交する方向において、偏光フィルム全体としての収縮量を小さくすることができるため、その結果、偏光子の両面に低透湿保護フィルムを積層しても、偏光フィルムに貫通クラックが発生することを抑制することができるものである。 In the present invention, as described above, since the protective plate is bonded to the first resin film of the polarizing film, severe heat shock (for example, heat shock test in which temperature conditions of −40 ° C. and 85 ° C. are repeated) is severe. The amount of shrinkage of the entire polarizing film can be reduced in a direction perpendicular to the absorption axis of the polarizer even in a difficult environment or a humidified environment. As a result, low moisture permeation protection is provided on both sides of the polarizer. Even when the films are laminated, it is possible to suppress the occurrence of through cracks in the polarizing film.
本発明の偏光フィルムの構成について図1を参照しながら詳細に説明する。なお、図1における各構成の寸法は、その一例を示すものであり、本発明はこれに限定されるものではない。 The configuration of the polarizing film of the present invention will be described in detail with reference to FIG. In addition, the dimension of each structure in FIG. 1 shows the example, and this invention is not limited to this.
図1に示すように、本発明の偏光フィルム1は、偏光子2の一方の面に、第1樹脂フィルム3を有し、他方の面に、第2樹脂フィルム4を有する。また、前記第1樹脂フィルム3の前記偏光子2を有さない側に、保護板5を有するものである。第1樹脂フィルム3及び第2樹脂フィルム4は、接着剤層(不図示)を介して前記偏光子2に貼り合せることができる。また、前記保護板5は、接着剤層又は接着剤層(不図示)を介して前記第1樹脂フィルム3に貼り合せることができる。また、本発明の偏光フィルム1は、前記層以外の層(例えば、易接着剤層や各種機能層等)を含むことができる。
As shown in FIG. 1, the
また、前記第1樹脂フィルム3は、前記偏光子2の視認側に配置されることが好ましく、第2樹脂フィルム4は、前記偏光子2の画像表示セル側に配置されることが好ましい。
The
以下、それぞれの構成要素について説明する。 Hereinafter, each component will be described.
(1)偏光子
本発明においては、厚みが10μm以下の薄型偏光子を用いる。偏光子の厚みは、薄型化及び貫通クラックの発生を抑える観点から8μm以下であるのが好ましく、さらには7μm以下、さらには6μm以下であるのが好ましい。一方、偏光子の厚みは2μm以上、さらには3μm以上であるのが好ましい。このような薄型の偏光子は、厚みムラが少なく、視認性が優れており、また寸法変化が少ないため熱衝撃に対する耐久性に優れる。
(1) Polarizer In the present invention, a thin polarizer having a thickness of 10 μm or less is used. The thickness of the polarizer is preferably 8 μm or less, more preferably 7 μm or less, and further preferably 6 μm or less from the viewpoint of reducing the thickness and preventing the occurrence of through cracks. On the other hand, the thickness of the polarizer is preferably 2 μm or more, and more preferably 3 μm or more. Such a thin polarizer has less thickness unevenness, excellent visibility, and less dimensional change, and therefore excellent durability against thermal shock.
偏光子は、ポリビニルアルコール系樹脂を用いたものが使用される。偏光子としては、例えば、ポリビニルアルコール系フィルム、部分ホルマール化ポリビニルアルコール系フィルム、エチレン・酢酸ビニル共重合体系部分ケン化フィルム等の親水性高分子フィルムに、ヨウ素や二色性染料の二色性物質を吸着させて一軸延伸したもの、ポリビニルアルコールの脱水処理物やポリ塩化ビニルの脱塩酸処理物等のポリエン系配向フィルム等が挙げられる。これらの中でも、ポリビニルアルコール系フィルムとヨウ素等の二色性物質からなる偏光子が好適である。 A polarizer using a polyvinyl alcohol resin is used. Examples of polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. Examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic substance such as iodine is preferable.
ポリビニルアルコール系フィルムをヨウ素で染色し一軸延伸した偏光子は、例えば、ポリビニルアルコールをヨウ素の水溶液に浸漬することによって染色し、元長の3~7倍に延伸することで作製することができる。必要に応じてホウ酸や硫酸亜鉛、塩化亜鉛等を含んでいても良いし、ヨウ化カリウム等の水溶液に浸漬することもできる。さらに必要に応じて染色前にポリビニルアルコール系フィルムを水に浸漬して水洗してもよい。ポリビニルアルコール系フィルムを水洗することでポリビニルアルコール系フィルム表面の汚れやブロッキング防止剤を洗浄することができるほかに、ポリビニルアルコール系フィルムを膨潤させることで染色のムラ等の不均一を防止する効果もある。延伸はヨウ素で染色した後に行っても良いし、染色しながら延伸しても良いし、また延伸してからヨウ素で染色しても良い。ホウ酸やヨウ化カリウム等の水溶液や水浴中でも延伸することができる。 A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol in an aqueous iodine solution and stretching it 3 to 7 times the original length. If necessary, it may contain boric acid, zinc sulfate, zinc chloride or the like, or may be immersed in an aqueous solution of potassium iodide or the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with stains and antiblocking agents by washing the polyvinyl alcohol film with water, the polyvinyl alcohol film is also swollen to prevent unevenness such as uneven coloring. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched even in an aqueous solution of boric acid or potassium iodide or in a water bath.
偏光子はホウ酸を含有していることが延伸安定性や加湿信頼性の点から好ましい。また、偏光子に含まれるホウ酸含有量は、貫通クラックの発生抑制の観点から、偏光子全量に対して22重量%以下であるのが好ましく、20重量%以下であるのがさらに好ましい。延伸安定性や加湿信頼性の観点から、偏光子全量に対するホウ酸含有量は10重量%以上であることが好ましく、さらには12重量%以上であることが好ましい。 The polarizer preferably contains boric acid from the viewpoint of stretching stability and humidification reliability. The boric acid content contained in the polarizer is preferably 22% by weight or less, more preferably 20% by weight or less, based on the total amount of the polarizer, from the viewpoint of suppressing the occurrence of through cracks. From the viewpoint of stretching stability and humidification reliability, the boric acid content with respect to the total amount of the polarizer is preferably 10% by weight or more, and more preferably 12% by weight or more.
薄型の偏光子としては、代表的には、特許第4751486号明細書、特許第4751481号明細書、特許第4815544号明細書、特許第5048120号明細書、国際公開第2014/077599号パンフレット、国際公開第2014/077636号パンフレット、等に記載されている薄型偏光子又はこれらに記載の製造方法から得られる薄型偏光子を挙げることができる。 As a thin polarizer, typically, Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, International Publication No. 2014/0777599, International Publication No. The thin polarizer described in the publication 2014/077636 pamphlet etc. or the thin polarizer obtained from the manufacturing method as described in these can be mentioned.
前記薄型偏光子としては、積層体の状態で延伸する工程と染色する工程を含む製法の中でも、高倍率に延伸できて偏光性能を向上させることのできる点で、特許第4751486号明細書、特許第4751481号明細書、特許4815544号明細書に記載のあるようなホウ酸水溶液中で延伸する工程を含む製法で得られるものが好ましく、特に特許第4751481号明細書、特許4815544号明細書に記載のあるホウ酸水溶液中で延伸する前に補助的に空中延伸する工程を含む製法により得られるものが好ましい。これら薄型偏光子は、ポリビニルアルコール系樹脂(以下、PVA系樹脂ともいう)層と延伸用樹脂基材を積層体の状態で延伸する工程と染色する工程を含む製法による得ることができる。この製法であれば、PVA系樹脂層が薄くても、延伸用樹脂基材に支持されていることにより延伸による破断等の不具合なく延伸することが可能となる。 As the thin polarizer, among the production methods including the step of stretching in the state of a laminate and the step of dyeing, Patent No. 4751486, Patent, in that it can be stretched at a high magnification and the polarization performance can be improved. What is obtained by the manufacturing method including the process of extending | stretching in a boric-acid aqueous solution as described in the 4751481 specification and the patent 4815544 specification is preferable, and it describes especially in the patent 4751481 specification and the patent 4815544 specification. What is obtained by the manufacturing method including the process of extending | stretching in the air auxiliary before extending | stretching in the boric-acid aqueous solution which has this is preferable. These thin polarizers can be obtained by a production method including a step of stretching and dyeing a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin base material in a laminated state. With this production method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching by being supported by the stretching resin substrate.
(2)第1樹脂フィルム
前記偏光子の一方の面に設けられる第1樹脂フィルムを形成する材料としては、透明性を有し、かつ、透湿度が、30g/(m2・day)以下であるフィルムを形成できる材料であればよい。具体的には、例えば、シクロオレフィン系樹脂フィルム等を挙げることができる。
(2) 1st resin film As a material which forms the 1st resin film provided in one surface of the said polarizer, it has transparency and a water vapor transmission rate is 30 g / (m < 2 > * day) or less. Any material that can form a certain film may be used. Specific examples include a cycloolefin resin film.
前記シクロオレフィン系樹脂フィルムは、透湿度が30g/(m2・day)以下である限り、公知のものを特に制限なく使用できる。シクロオレフィン系樹脂は、シクロオレフィンを重合単位として重合される樹脂の総称であり、例えば、特開平1-240517号公報、特開平3-14882号公報、特開平3-122137号公報等に記載されている樹脂が挙げられる。具体例としては、シクロオレフィンの開環(共)重合体、シクロオレフィンの付加重合体、シクロオレフィンとエチレン、プロピレン等のα-オレフィンとの共重合体(代表的にはランダム共重合体)、これらを不飽和カルボン酸やその誘導体で変性したグラフト重合体、及びそれらの水素化物等が挙げられる。シクロオレフィンの具体例としては、ノルボルネン系モノマーが挙げられる。 As the cycloolefin resin film, a known film can be used without particular limitation as long as the moisture permeability is 30 g / (m 2 · day) or less. The cycloolefin-based resin is a general term for resins that are polymerized using a cycloolefin as a polymerization unit, and is described in, for example, JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, and the like. Resin. Specific examples include cycloolefin ring-opening (co) polymers, cycloolefin addition polymers, copolymers of cycloolefins with α-olefins such as ethylene and propylene (typically random copolymers), Examples thereof include graft polymers obtained by modifying these with unsaturated carboxylic acids or derivatives thereof, and hydrides thereof. Specific examples of the cycloolefin include norbornene monomers.
シクロオレフィン系樹脂としては、種々の製品が市販されている。具体例としては、日本ゼオン(株)製の商品名「ゼオネックス」、「ゼオノア」、JSR(株)製の商品名「アートン」、TICONA社製の商品名「トーパス」、三井化学(株)製の商品名「APEL」等が挙げられる。 Various products are commercially available as cycloolefin resins. Specific examples include trade names “ZEONEX” and “ZEONOR” manufactured by ZEON CORPORATION, trade names “ARTON” manufactured by JSR Corporation, “TOPASS” manufactured by TICONA, and products manufactured by Mitsui Chemicals, Inc. Product name “APEL” and the like.
前記第1樹脂フィルムの透湿度は、30g/(m2・day)以下であり、25g/(m2・day)以下であることが好ましく、20g/(m2・day)以下であることがより好ましい。また、透湿度の下限値は特に限定されるものではないが、理想的には、水蒸気を全く透過させないこと(すなわち、0g/(m2・day))が好ましい。第1樹脂フィルムの透湿度が前記範囲であることにより、偏光子の水分による劣化を抑制することができる。 The moisture permeability of the first resin film is 30 g / (m 2 · day) or less, preferably 25 g / (m 2 · day) or less, and preferably 20 g / (m 2 · day) or less. More preferred. Further, the lower limit value of moisture permeability is not particularly limited, but ideally, it is preferable that water vapor is not permeated at all (that is, 0 g / (m 2 · day)). When the moisture permeability of the first resin film is in the above range, deterioration of the polarizer due to moisture can be suppressed.
前記第1樹脂フィルムの厚みは、特に限定されるものではないが、透湿度を低くして加湿信頼性を高め、また破壊強度を高めて貫通クラックをより抑制する観点からは、10μm以上であることが好ましく、12μm以上であることがより好ましい。一方で、薄型化の観点からは、40μm以下であることが好ましく、30μm以下であることがより好ましい。 The thickness of the first resin film is not particularly limited, but is 10 μm or more from the viewpoint of lowering moisture permeability to increase humidification reliability and further increasing fracture strength to further suppress penetration cracks. It is preferable that it is 12 μm or more. On the other hand, from the viewpoint of thinning, it is preferably 40 μm or less, and more preferably 30 μm or less.
前記第1樹脂フィルムの線膨張係数は、特に限定されるものではないが、例えば、前記偏光子の吸収軸に直交する方向において、5.0×10-5~8.0×10-5/K程度を挙げることができ、5.5×10-5~7.5×10-5/K程度であってもよい。本発明の偏光フィルムは、透湿度が極めて低く、かつ前記範囲の線膨張係数を有する第1樹脂フィルムを使用した場合であっても、貫通クラックの発生を抑制することができるものである。線膨張係数については、実施例に記載の測定方法により測定することができる。 The linear expansion coefficient of the first resin film is not particularly limited. For example, in the direction orthogonal to the absorption axis of the polarizer, 5.0 × 10 −5 to 8.0 × 10 −5 / K may be mentioned, and it may be about 5.5 × 10 −5 to 7.5 × 10 −5 / K. The polarizing film of the present invention can suppress the occurrence of through cracks even when the first resin film having extremely low moisture permeability and a linear expansion coefficient in the above range is used. About a linear expansion coefficient, it can measure with the measuring method as described in an Example.
また、前記第1樹脂フィルムの破断強度は、特に限定されるものではないが、例えば、前記偏光子の吸収軸に直交する方向において、5~30N程度を挙げることができ、8~25N程度であってもよく、8~23N程度であってもよい。本発明の偏光フィルムは、透湿度が極めて低く、かつ前記範囲の破断強度を有する第1樹脂フィルムを使用した場合であっても、貫通クラックの発生を抑制することができるものである。破断強度については、実施例に記載の測定方法により測定することができる。 Further, the breaking strength of the first resin film is not particularly limited. For example, in the direction perpendicular to the absorption axis of the polarizer, it can be about 5 to 30 N, and about 8 to 25 N. It may be about 8 to 23N. Even if the polarizing film of this invention is a case where the 1st resin film which has very low moisture permeability and has the breaking strength of the said range is used, generation | occurrence | production of a through crack can be suppressed. About breaking strength, it can measure by the measuring method as described in an Example.
また、前記第1樹脂フィルムを85℃で120時間の加熱処理した際の寸法変化率は、特に限定されるものではないが、例えば、前記偏光子の吸収軸に直交する方向において、-0.40~0%程度を挙げることができ、-0.34~0%程度であってもよく、-0.33~-0.01%程度であってもよい。本発明の偏光フィルムは、透湿度が極めて低く、かつ前記範囲の寸法変化率を有する第1樹脂フィルムを使用した場合であっても貫通クラックの発生を抑制することができるものである。寸法変化率については、実施例に記載の測定方法により測定することができる。 The dimensional change rate when the first resin film is heat-treated at 85 ° C. for 120 hours is not particularly limited. For example, in the direction perpendicular to the absorption axis of the polarizer, −0. It can be about 40 to 0%, can be about -0.34 to 0%, or can be about -0.33 to -0.01%. The polarizing film of the present invention can suppress the occurrence of through cracks even when the first resin film having extremely low moisture permeability and a dimensional change rate in the above range is used. About a dimensional change rate, it can measure by the measuring method as described in an Example.
前記偏光子と第1樹脂フィルムとは、加湿信頼性の観点から、通常、活性エネルギー線硬化型接着剤等の接着剤を介して密着している。活性エネルギー線硬化型接着剤は、電子線、紫外線(ラジカル硬化型、カチオン硬化型)等の活性エネルギー線により硬化が進行する接着剤であり、例えば、電子線硬化型、紫外線硬化型の態様で用いることができる。活性エネルギー線硬化型接着剤は、例えば、光ラジカル硬化型接着剤を用いることができる。光ラジカル硬化型の活性エネルギー線硬化型接着剤を、紫外線硬化型として用いる場合には、当該接着剤は、ラジカル重合性化合物及び光重合開始剤を含有する。接着剤の塗工方式は、接着剤の粘度や目的とする厚みによって適宜に選択される。塗工方式の例として、例えば、リバースコーター、グラビアコーター(ダイレクト,リバースやオフセット)、バーリバースコーター、ロールコーター、ダイコーター、バーコーター、ロッドコーター等が挙げられる。その他、塗工には、デイッピング方式等の方式を適宜に使用することができる。 The polarizer and the first resin film are usually in close contact with each other through an adhesive such as an active energy ray-curable adhesive from the viewpoint of humidification reliability. The active energy ray curable adhesive is an adhesive that cures by an active energy ray such as an electron beam or ultraviolet rays (radical curable type, cationic curable type), for example, in an electron beam curable type or an ultraviolet curable type. Can be used. As the active energy ray curable adhesive, for example, a photo radical curable adhesive can be used. When the photo radical curable active energy ray curable adhesive is used as an ultraviolet curable adhesive, the adhesive contains a radical polymerizable compound and a photo polymerization initiator. The adhesive coating method is appropriately selected depending on the viscosity of the adhesive and the target thickness. Examples of coating methods include reverse coaters, gravure coaters (direct, reverse and offset), bar reverse coaters, roll coaters, die coaters, bar coaters, rod coaters and the like. In addition, for coating, a method such as a dapping method can be appropriately used.
前記第1樹脂フィルムの偏光子を接着させない面には、ハードコート層や反射防止処理、スティッキング防止や、拡散ないしアンチグレアを目的とした処理を施したものであっても良い。 The surface of the first resin film to which the polarizer is not adhered may be subjected to a treatment for the purpose of hard coat layer, antireflection treatment, sticking prevention, diffusion or antiglare.
(3)第2樹脂フィルム
前記偏光子の第1樹脂フィルムを形成した面の反対側の面には、第2樹脂フィルムを有する。前記第2樹脂フィルムを形成する材料としては、透明性を有し、かつ、透湿度が、30g/(m2・day)以下であるフィルムを形成できる材料であればよい。具体的には、例えば、シクロオレフィン系樹脂フィルム等を挙げることができる。
(3) 2nd resin film It has a 2nd resin film in the surface on the opposite side to the surface in which the 1st resin film of the said polarizer was formed. The material for forming the second resin film may be any material that can form a film having transparency and moisture permeability of 30 g / (m 2 · day) or less. Specific examples include a cycloolefin resin film.
前記シクロオレフィン系樹脂フィルムとしては、第1樹脂フィルムで挙げられたものを挙げることができる。 Examples of the cycloolefin-based resin film include those listed for the first resin film.
前記第2樹脂フィルムの透湿度は、30g/(m2・day)以下であり、25g/(m2・day)以下であることが好ましく、20g/(m2・day)以下であることがより好ましい。また、透湿度の下限値は特に限定されるものではないが、理想的には、水蒸気を全く透過させないこと(すなわち、0g/(m2・day))が好ましい。第2樹脂フィルムの透湿度が前記範囲であることにより、偏光子の水分による劣化を抑制することができる。 The moisture permeability of the second resin film is 30 g / (m 2 · day) or less, preferably 25 g / (m 2 · day) or less, and preferably 20 g / (m 2 · day) or less. More preferred. Further, the lower limit value of moisture permeability is not particularly limited, but ideally, it is preferable that water vapor is not permeated at all (that is, 0 g / (m 2 · day)). When the moisture permeability of the second resin film is within the above range, deterioration of the polarizer due to moisture can be suppressed.
前記第2樹脂フィルムの厚みは、特に限定されるものではないが、透湿度を低くして加湿信頼性を高め、また破壊強度を高めて貫通クラックをより抑制する観点からは、10μm以上であることが好ましく、12μm以上であることがより好ましい。一方で、薄型化の観点からは、40μm以下であることが好ましく、30μm以下であることがより好ましい。 The thickness of the second resin film is not particularly limited, but is 10 μm or more from the viewpoint of lowering moisture permeability to increase humidification reliability and further increasing fracture strength to further suppress penetration cracks. It is preferable that it is 12 μm or more. On the other hand, from the viewpoint of thinning, it is preferably 40 μm or less, and more preferably 30 μm or less.
前記第2樹脂フィルムの線膨張係数は、特に限定されるものではないが、例えば、前記偏光子の吸収軸に直交する方向において、5.0×10-5~8.0×10-5/K程度を挙げることができ、5.5×10-5~7.5×10-5/K程度であってもよい。本発明の偏光フィルムは、透湿度が極めて低く、かつ前記範囲の線膨張係数を有する第2樹脂フィルムを使用した場合であっても、貫通クラックの発生を抑制することができるものである。線膨張係数については、実施例に記載の測定方法により測定することができる。 The linear expansion coefficient of the second resin film is not particularly limited. For example, in the direction orthogonal to the absorption axis of the polarizer, 5.0 × 10 −5 to 8.0 × 10 −5 / K may be mentioned, and it may be about 5.5 × 10 −5 to 7.5 × 10 −5 / K. The polarizing film of the present invention can suppress the occurrence of through cracks even when the second resin film having extremely low moisture permeability and a linear expansion coefficient in the above range is used. About a linear expansion coefficient, it can measure with the measuring method as described in an Example.
また、前記第2樹脂フィルムの破断強度は、特に限定されるものではないが、例えば、前記偏光子の吸収軸に直交する方向において、5~30N程度を挙げることができ、8~25N程度であってもよく、8~23N程度であってもよい。本発明の偏光フィルムは、透湿度が極めて低く、かつ前記範囲の破断強度を有する第2樹脂フィルムを使用した場合であっても、貫通クラックの発生を抑制することができるものである。破断強度については、実施例に記載の測定方法により測定することができる。 Further, the breaking strength of the second resin film is not particularly limited. For example, in the direction perpendicular to the absorption axis of the polarizer, it can be about 5 to 30 N, and about 8 to 25 N. It may be about 8 to 23N. The polarizing film of the present invention can suppress the occurrence of through cracks even when a second resin film having extremely low moisture permeability and a breaking strength in the above range is used. About breaking strength, it can measure by the measuring method as described in an Example.
また、前記第2樹脂フィルムを85℃で120時間の加熱処理した際の寸法変化率は、特に限定されるものではないが、例えば、前記偏光子の吸収軸に直交する方向において、-0.40~0%程度を挙げることができ、-0.34~0%程度であってもよく、-0.33~-0.01%程度であってもよい。本発明の偏光フィルムは、透湿度が極めて低く、かつ前記範囲の寸法変化率を有する第2樹脂フィルムを使用した場合であっても貫通クラックの発生を抑制することができるものである。寸法変化率については、実施例に記載の測定方法により測定することができる。 The dimensional change rate when the second resin film is heat-treated at 85 ° C. for 120 hours is not particularly limited. For example, in the direction perpendicular to the absorption axis of the polarizer, −0. It can be about 40 to 0%, can be about -0.34 to 0%, or can be about -0.33 to -0.01%. The polarizing film of the present invention can suppress the occurrence of through cracks even when the second resin film having extremely low moisture permeability and a dimensional change rate in the above range is used. About a dimensional change rate, it can measure by the measuring method as described in an Example.
前記偏光子と第2樹脂フィルムとは、通常、接着剤を介して密着している。接着剤としては第1樹脂フィルムで挙げたものを挙げることができる。 The polarizer and the second resin film are usually in close contact via an adhesive. Examples of the adhesive include those listed for the first resin film.
前記第2樹脂フィルムの偏光子を接着させない面には、ハードコート層や反射防止処理、スティッキング防止や、拡散ないしアンチグレアを目的とした処理を施したものであっても良い。 The surface of the second resin film to which the polarizer is not adhered may be subjected to a treatment for the purpose of hard coat layer, antireflection treatment, sticking prevention, diffusion or antiglare.
(4)保護板
本発明の偏光フィルムには、前記第1樹脂フィルムの前記偏光子を有さない側に、保護板を有するものである。保護板を設けることにより、ヒートショック試験時における偏光子の収縮量を抑制することができるため、貫通クラックの発生を抑制することができる。
(4) Protection plate The polarizing film of the present invention has a protection plate on the side of the first resin film that does not have the polarizer. By providing the protective plate, it is possible to suppress the amount of contraction of the polarizer during the heat shock test, and thus it is possible to suppress the occurrence of through cracks.
保護板としては、特に限定されるものではなく、本発明の偏光フィルムを熱衝撃環境下に曝した場合にも偏光フィルムの収縮を抑制することができるものであればよい。 The protective plate is not particularly limited as long as it can suppress the shrinkage of the polarizing film even when the polarizing film of the present invention is exposed to a thermal shock environment.
前記保護板の線膨張係数が、前記偏光子の吸収軸に直交する方向において、1.0×10-5/K以下であることが好ましく、9.0×10-6/K以下であることがより好ましく、8.0×10-6/K以下であることがさらに好ましい。前記偏光子の吸収軸に直交する方向において、前記保護板の線膨張係数が前記範囲であると、ヒートショック試験において、保護板が偏光子の収縮量を抑制することができるため、貫通クラックが発生するのをより効果的に抑制することができる。また、線膨張係数の下限値は、特に限定されるものではないが、例えば、1.0×10-6/K以上であることが好ましい。 The linear expansion coefficient of the protective plate is preferably 1.0 × 10 −5 / K or less in the direction perpendicular to the absorption axis of the polarizer, and is 9.0 × 10 −6 / K or less. Is more preferably 8.0 × 10 −6 / K or less. In the direction perpendicular to the absorption axis of the polarizer, if the linear expansion coefficient of the protective plate is in the above range, in the heat shock test, the protective plate can suppress the amount of contraction of the polarizer. Generation | occurrence | production can be suppressed more effectively. Further, the lower limit value of the linear expansion coefficient is not particularly limited, but is preferably 1.0 × 10 −6 / K or more, for example.
前記保護板の厚みは、特に限定されるものではないが、0.5~1.0mmであることが好ましく、0.5~0.8mmであることがより好ましい。保護板の厚みが前記範囲にあることで、寸法収縮しにくいため好ましい。 The thickness of the protective plate is not particularly limited, but is preferably 0.5 to 1.0 mm, and more preferably 0.5 to 0.8 mm. It is preferable that the thickness of the protective plate is in the above range because the size does not easily shrink.
前記保護板の鉛筆硬度は、8H以上であることが好ましく、10H以上であることがより好ましい。保護板の鉛筆硬度が前記範囲にあることで、寸法収縮しにくいため好ましい。前記鉛筆硬度は、JIS K 5600-5-4の規定に準じた鉛筆硬度である。 The pencil hardness of the protective plate is preferably 8H or more, and more preferably 10H or more. Since the pencil hardness of the protective plate is in the above range, it is preferable because the size does not easily shrink. The pencil hardness is a pencil hardness according to JIS K 5600-5-4.
前記保護板の比重は、2.0以上であることが好ましく、2.3以上であることがより好ましい。保護板の比重が前記範囲にあることで、寸法収縮しにくいため好ましい。 The specific gravity of the protective plate is preferably 2.0 or more, and more preferably 2.3 or more. It is preferable that the specific gravity of the protective plate is in the above-mentioned range because it is difficult to shrink the dimensions.
前記保護板の熱伝導率は、2.0W/(m・K)以下であることが好ましく、1.5W/(m・K)以下であることがより好ましい。保護板の熱伝導率が前記範囲にあることで、ヒートショック試験においても熱が偏光子に伝わりにくく、前記偏光子の吸収軸に直交する方向において、偏光子の収縮量を抑制することができるため好ましい。 The thermal conductivity of the protective plate is preferably 2.0 W / (m · K) or less, and more preferably 1.5 W / (m · K) or less. Since the thermal conductivity of the protective plate is within the above range, heat is not easily transmitted to the polarizer even in a heat shock test, and the amount of contraction of the polarizer can be suppressed in a direction perpendicular to the absorption axis of the polarizer. Therefore, it is preferable.
前記保護板を形成する材料としては、特に限定されるものではないが、ガラス、アクリル板等を挙げることができる。これらの中でも、ガラスが好ましい。 The material for forming the protective plate is not particularly limited, and examples thereof include glass and an acrylic plate. Among these, glass is preferable.
保護板と前記第1樹脂フィルムとは、接着剤層又は粘着剤層を介して積層することができる。接着剤層としては、本明細書に記載の接着剤層を適宜用いることができる。 The protective plate and the first resin film can be laminated via an adhesive layer or an adhesive layer. As the adhesive layer, the adhesive layer described in this specification can be used as appropriate.
前記粘着剤層としては、特に限定されるものではなく、公知のものを用いることができる。このような粘着剤層としては、具体的には、例えば、(メタ)アクリル系ポリマー、シリコーン系ポリマー、ポリエステル、ポリウレタン、ポリアミド、ポリエーテル、フッ素系やゴム系等のポリマーをベースポリマーとするものを適宜に選択して用いることができる。これらの中でも、(メタ)アクリル系ポリマーをベースポリマーとするアクリル系粘着剤が、光学的透明性に優れ、適度な濡れ性と凝集性と接着性の粘着特性を示して、耐候性や耐熱性等に優れているため、好ましい。 The pressure-sensitive adhesive layer is not particularly limited, and a known layer can be used. As such an adhesive layer, specifically, for example, a (meth) acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based or a rubber-based polymer is used as a base polymer. Can be appropriately selected and used. Among these, acrylic pressure-sensitive adhesives based on (meth) acrylic polymers are excellent in optical transparency, exhibiting moderate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, weather resistance and heat resistance. Etc. are preferable.
前記(メタ)アクリル系ポリマーとしては、特に限定されるものではないが、炭素数4~24のアルキル基をエステル基の末端に有するアルキル(メタ)アクリレートを含むモノマー成分を重合することにより得られたものを挙げることができる。なお、アルキル(メタ)アクリレートは、アルキルアクリレート及び/又はアルキルメタクリレートをいい、本発明の(メタ)とは同様の意味である。 The (meth) acrylic polymer is not particularly limited, and can be obtained by polymerizing a monomer component containing an alkyl (meth) acrylate having an alkyl group having 4 to 24 carbon atoms at the terminal of the ester group. Can be mentioned. Alkyl (meth) acrylate refers to alkyl acrylate and / or alkyl methacrylate, and (meth) in the present invention has the same meaning.
アルキル(メタ)アクリレートとしては、直鎖状又は分岐鎖状の炭素数4~24のアルキル基を有すものを例示でき、直鎖状又は分岐鎖状の炭素数4~9のアルキル基を有するアルキル(メタ)アクリレートが、粘着特性のバランスがとりやすい点で好ましい。これらのアルキル(メタ)アクリレートは1種を単独で又は2種以上を組み合わせて用いることができる。 Examples of the alkyl (meth) acrylate include those having a linear or branched alkyl group having 4 to 24 carbon atoms, and having a linear or branched alkyl group having 4 to 9 carbon atoms. Alkyl (meth) acrylates are preferred because they are easy to balance the adhesive properties. These alkyl (meth) acrylates can be used alone or in combination of two or more.
(メタ)アクリル系ポリマーを形成するモノマー成分には、単官能性モノマー成分として、前記アルキル(メタ)アクリレート以外の共重合モノマーを含有することができる。このような共重合モノマーとしては、例えば、環状窒素含有モノマー、ヒドロキシル基含有モノマー、カルボキシル基含有モノマー、環状エーテル基を有するモノマー等が挙げられる。 The monomer component forming the (meth) acrylic polymer can contain a copolymerizable monomer other than the alkyl (meth) acrylate as a monofunctional monomer component. Examples of such copolymerizable monomers include cyclic nitrogen-containing monomers, hydroxyl group-containing monomers, carboxyl group-containing monomers, and monomers having a cyclic ether group.
また、(メタ)アクリル系ポリマーを形成するモノマー成分には、前記単官能性モノマーの他に、粘着剤の凝集力を調整するために、必要に応じて多官能性モノマーを含有することができる。前記多官能性モノマーは、(メタ)アクリロイル基又はビニル基等の不飽和二重結合を有する重合性の官能基を少なくとも2つ有するモノマーであり、例えば、ジペンタエリスリトールヘキサ(メタ)アクリレート、1,6-ヘキサンジオールジ(メタ)アクリレート、トリメチロールプロパントリ(メタ)アクリレートが挙げられる。多官能性モノマーは、1種を単独で又は2種以上を組み合わせて使用することができる。 In addition to the monofunctional monomer, the monomer component forming the (meth) acrylic polymer can contain a polyfunctional monomer as necessary in order to adjust the cohesive force of the pressure-sensitive adhesive. . The polyfunctional monomer is a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, such as dipentaerythritol hexa (meth) acrylate, 1 , 6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate. A polyfunctional monomer can be used individually by 1 type or in combination of 2 or more types.
このような(メタ)アクリル系ポリマーの製造は、溶液重合、紫外線重合等の放射線重合、塊状重合、乳化重合等の各種ラジカル重合等の公知の製造方法を適宜選択できる。また、得られる(メタ)アクリル系ポリマーは、ランダム共重合体、ブロック共重合体、グラフト共重合体等いずれでもよい。 The production of such a (meth) acrylic polymer can be appropriately selected from known production methods such as radiation polymerization such as solution polymerization and ultraviolet polymerization, various radical polymerizations such as bulk polymerization and emulsion polymerization. Further, the (meth) acrylic polymer obtained may be a random copolymer, a block copolymer, a graft copolymer or the like.
ラジカル重合に用いられる重合開始剤、連鎖移動剤、乳化剤等は特に限定されず、本分野において通常用いられる公知のものを適宜選択して使用することができる。また、(メタ)アクリル系ポリマーの重量平均分子量は、重合開始剤、連鎖移動剤の使用量、反応条件により制御可能であり、これらの種類に応じて適宜のその使用量が調整される。 The polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited, and known ones commonly used in this field can be appropriately selected and used. In addition, the weight average molecular weight of the (meth) acrylic polymer can be controlled by the amount of polymerization initiator, the amount of chain transfer agent used, and the reaction conditions, and the amount used is appropriately adjusted according to these types.
本発明で用いる(メタ)アクリル系ポリマーの重量平均分子量は40万~400万であるのが好ましい。重量平均分子量を40万より大きくすることで、粘着剤層の耐久性を満足させたり、粘着剤層の凝集力が小さくなって糊残りが生じるのを抑えることができる。一方、重量平均分子量が400万よりも大きくなると貼り合せ性が低下する傾向がある。さらに、粘着剤が溶液系において、粘度が高くなりすぎ、塗工が困難になる場合がある。なお、重量平均分子量は、GPC(ゲルパーミネーション・クロマトグラフィー)により測定し、ポリスチレン換算により算出された値をいう。なお、放射線重合で得られた(メタ)アクリル系ポリマーについては、分子量測定は困難である。 The weight average molecular weight of the (meth) acrylic polymer used in the present invention is preferably 400,000 to 4,000,000. By making the weight average molecular weight larger than 400,000, it is possible to satisfy the durability of the pressure-sensitive adhesive layer, or to suppress the occurrence of adhesive residue due to the reduced cohesive force of the pressure-sensitive adhesive layer. On the other hand, when the weight average molecular weight is larger than 4 million, the bonding property tends to be lowered. Furthermore, in the solution system, the viscosity becomes too high, and coating may be difficult. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene. In addition, it is difficult to measure the molecular weight of the (meth) acrylic polymer obtained by radiation polymerization.
本発明で用いる粘着剤組成物には、架橋剤を含有することができる。架橋剤としては、イソシアネート系架橋剤、エポキシ系架橋剤、シリコーン系架橋剤、オキサゾリン系架橋剤、アジリジン系架橋剤、シラン系架橋剤、アルキルエーテル化メラミン系架橋剤、金属キレート系架橋剤、過酸化物等の架橋剤を挙げることができ、これらを1種単独で又は2種以上を組み合わせて用いることができる。前記架橋剤としては、イソシアネート系架橋剤、エポキシ系架橋剤が好ましく用いられる。 The pressure-sensitive adhesive composition used in the present invention can contain a crosslinking agent. Examples of crosslinking agents include isocyanate crosslinking agents, epoxy crosslinking agents, silicone crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, silane crosslinking agents, alkyletherified melamine crosslinking agents, metal chelate crosslinking agents, Examples of the crosslinking agent include oxides, and these can be used alone or in combination of two or more. As said crosslinking agent, an isocyanate type crosslinking agent and an epoxy-type crosslinking agent are used preferably.
上記架橋剤は1種を単独で使用してもよく、また2種以上を混合して使用してもよいが、全体としての含有量は、前記(メタ)アクリル系ポリマー100重量部に対し、前記架橋剤を0.01~10重量部の範囲で含有することが好ましい。 The crosslinking agent may be used alone or in combination of two or more, but the total content is based on 100 parts by weight of the (meth) acrylic polymer. The crosslinking agent is preferably contained in the range of 0.01 to 10 parts by weight.
本発明において用いる粘着剤組成物には、接着力を向上させるために、(メタ)アクリル系オリゴマーを含有させることができる。さらに、本発明において用いる粘着剤組成物には、粘着剤層のガラス等の親水性被着体に適用する場合における界面での耐水性を上げるためにシランカップリング剤を含有することができる。 In the pressure-sensitive adhesive composition used in the present invention, a (meth) acrylic oligomer can be contained in order to improve the adhesive force. Furthermore, the pressure-sensitive adhesive composition used in the present invention may contain a silane coupling agent in order to increase the water resistance at the interface when applied to a hydrophilic adherend such as glass of the pressure-sensitive adhesive layer.
さらに本発明で用いる粘着剤組成物には、その他の公知の添加剤を含有していてもよく、例えば、ポリプロピレングリコール等のポリアルキレングリコールのポリエーテル化合物、着色剤、顔料等の粉体、染料、界面活性剤、可塑剤、粘着性付与剤、表面潤滑剤、レベリング剤、軟化剤、酸化防止剤、老化防止剤、光安定剤、紫外線吸収剤、重合禁止剤、無機又は有機の充填剤、金属粉、粒子状、箔状物等を使用する用途に応じて適宜添加することができる。また、制御できる範囲内で、還元剤を加えてのレドックス系を採用してもよい。 Furthermore, the pressure-sensitive adhesive composition used in the present invention may contain other known additives, such as polyether compounds of polyalkylene glycols such as polypropylene glycol, powders of colorants and pigments, dyes, and the like. , Surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, UV absorbers, polymerization inhibitors, inorganic or organic fillers, It can be added as appropriate depending on the application in which metal powder, particles, foil, etc. are used. Moreover, you may employ | adopt the redox system which added a reducing agent within the controllable range.
粘着剤層の形成方法は、公知の方法により行うことができる。 The formation method of the pressure-sensitive adhesive layer can be performed by a known method.
また、保護板と前記第1樹脂フィルムとを積層するための粘着剤層として、日東電工(株)製の「LUCIACS」、三菱樹脂(株)製の「クリアフィット」、デクセリアルズ(株)製の「光学弾性樹脂(SVR)」等の粘着剤層(粘着シート)等の市販品も好適に用いることができる。 In addition, as an adhesive layer for laminating the protective plate and the first resin film, “LUCIACS” manufactured by Nitto Denko Corporation, “Clear Fit” manufactured by Mitsubishi Plastics Co., Ltd., manufactured by Dexerials Corporation Commercial products such as a pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet) such as “optical elastic resin (SVR)” can also be suitably used.
本発明の偏光フィルムの85℃、85%R.H.環境下に500時間放置後の偏光度変化率の絶対値は、0.1%未満であることが好ましく、0.05%以下であることがより好ましく、0.03%以下であることがさらに好ましい。本発明の偏光フィルムは、第1樹脂フィルム上に保護板を貼り合せているため、熱衝撃(例えば、-40℃と85℃の温度条件を繰り返すヒートショック試験)の過酷な環境下やにおいても、偏光フィルム全体としての収縮力が極めて小さくなり、さらに、低透湿保護フィルムを用いているため偏光子の水による劣化が抑制され、その結果、過酷な環境下に曝されても、偏光度変化が小さく、光学特性に優れるものである。 The 85 ° C. and 85% R.V. of the polarizing film of the present invention. H. The absolute value of the degree of polarization change after standing in the environment for 500 hours is preferably less than 0.1%, more preferably 0.05% or less, and further preferably 0.03% or less. preferable. Since the polarizing film of the present invention has a protective plate laminated on the first resin film, it can be used in a severe environment of thermal shock (for example, a heat shock test in which temperature conditions of −40 ° C. and 85 ° C. are repeated). In addition, the shrinkage force of the polarizing film as a whole becomes extremely small, and furthermore, since the low moisture permeation protective film is used, the deterioration of the polarizer due to water is suppressed, and as a result, even when exposed to harsh environments, the degree of polarization The change is small and the optical characteristics are excellent.
2.粘着剤層付き偏光フィルム
本発明の粘着剤層付き偏光フィルムは、前記偏光フィルムの前記第2樹脂フィルム側に粘着剤層を有することを特徴とする。
2. The polarizing film with an adhesive layer The polarizing film with an adhesive layer of this invention has an adhesive layer in the said 2nd resin film side of the said polarizing film, It is characterized by the above-mentioned.
前記粘着剤層は、第2樹脂フィルムの偏光子を有さない側に積層することができる。具体的には、図2に示すように、本発明の粘着剤層付き偏光フィルム10は、保護板5、第1樹脂フィルム3、偏光子2、第2樹脂フィルム4、粘着剤層6をこの順に有するものである。
The pressure-sensitive adhesive layer can be laminated on the side having no polarizer of the second resin film. Specifically, as shown in FIG. 2, the
本発明の粘着剤層付き偏光フィルムは、前記保護板を有する偏光フィルムの第2樹脂フィルム上に直接粘着剤組成物を塗布し、加熱乾燥等により溶媒等を除去することにより、粘着剤層を形成することができる。また、支持体等に形成した粘着剤層を、前記偏光フィルムの第2樹脂フィルム上に転写して、粘着剤層付き偏光フィルムを形成することもできる。 The polarizing film with the pressure-sensitive adhesive layer of the present invention is obtained by directly applying the pressure-sensitive adhesive composition on the second resin film of the polarizing film having the protective plate, and removing the solvent and the like by heating and drying. Can be formed. Moreover, the adhesive layer formed in the support body etc. can be transcribe | transferred on the 2nd resin film of the said polarizing film, and a polarizing film with an adhesive layer can also be formed.
前記粘着剤組成物としては、本明細書に記載のものを適宜用いることができるが、なかでも、前述の(メタ)アクリル系ポリマーをベースポリマーとするアクリル系粘着剤が好ましい。 As the pressure-sensitive adhesive composition, those described in the present specification can be appropriately used, and among them, an acrylic pressure-sensitive adhesive having the above-mentioned (meth) acrylic polymer as a base polymer is preferable.
粘着剤組成物の塗布方法としては、各種方法が用いられる。具体的には、例えば、ロールコート、キスロールコート、グラビアコート、リバースコート、ロールブラッシュ、スプレーコート、ディップロールコート、バーコート、ナイフコート、エアーナイフコート、カーテンコート、リップコート、ダイコーター等による押出しコート法等の方法が挙げられる。 Various methods are used as a method for applying the pressure-sensitive adhesive composition. Specifically, for example, by roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples thereof include an extrusion coating method.
前記加熱乾燥温度は、30℃~200℃程度が好ましく、40℃~180℃程度がより好ましく、80℃~150℃程度がさらに好ましい。加熱温度を上記の範囲とすることによって、優れた粘着特性を有する粘着剤層を得ることができる。乾燥時間は、適宜、適切な時間が採用され得る。上記乾燥時間は、5秒~20分程度が好ましく、30秒~10分程度がより好ましく、1分~8分がさらに好ましい。 The heating and drying temperature is preferably about 30 to 200 ° C, more preferably about 40 to 180 ° C, and further preferably about 80 to 150 ° C. By setting the heating temperature in the above range, an adhesive layer having excellent adhesive properties can be obtained. As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably about 5 seconds to 20 minutes, more preferably about 30 seconds to 10 minutes, and further preferably 1 minute to 8 minutes.
前記支持体としては、例えば、剥離処理したシート(セパレーター)を用いることができる。剥離処理したシートとしては、シリコーン剥離ライナーが好ましく用いられる。 As the support, for example, a peeled sheet (separator) can be used. A silicone release liner is preferably used as the release-treated sheet.
セパレーターの構成材料としては、例えば、ポリエチレン、ポリプロピレン、ポリエチレンテレフタレート、ポリエステルフィルム等のプラスチックフィルム、紙、布、不織布等の多孔質材料、ネット、発泡シート、金属箔、及びこれらのラミネート体等の適宜な薄葉体等を挙げることができるが、表面平滑性に優れる点からプラスチックフィルムが好適に用いられる。 Examples of the constituent material of the separator include, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and laminates thereof. Although a thin leaf body etc. can be mentioned, a plastic film is used suitably from the point which is excellent in surface smoothness.
前記プラスチックフィルムとしては、例えば、ポリエチレンフィルム、ポリプロピレンフィルム、ポリブテンフィルム、ポリブタジエンフィルム、ポリメチルペンテンフイルム、ポリ塩化ビニルフィルム、塩化ビニル共重合体フィルム、ポリエチレンテレフタレートフィルム、ポリブチレンテレフタレートフィルム、ポリウレタンフィルム、エチレン-酢酸ビニル共重合体フィルム等が挙げられる。 Examples of the plastic film include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene. -Vinyl acetate copolymer film and the like.
前記セパレーターの厚みは、通常5~200μm、好ましくは5~100μm程度である。前記セパレーターには、必要に応じて、シリコーン系、フッ素系、長鎖アルキル系もしくは脂肪酸アミド系の離型剤、シリカ粉等による離型、及び防汚処理や、塗布型、練り込み型、蒸着型等の帯電防止処理もすることもできる。特に、前記セパレーターの表面にシリコーン処理、長鎖アルキル処理、フッ素処理等の剥離処理を適宜行うことにより、前記粘着剤層からの剥離性をより高めることができる。 The thickness of the separator is usually about 5 to 200 μm, preferably about 5 to 100 μm. For the separator, silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, release by silica powder, and antifouling treatment, coating type, kneading type, vapor deposition, as required An antistatic treatment such as a mold can also be performed. In particular, the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the separator.
なお、上記の粘着剤層付き偏光フィルムの作製にあたって用いた、剥離処理したシートは、そのまま粘着剤層付き偏光フィルムのセパレーターとして用いることができ、工程面における簡略化ができる。 In addition, the sheet | seat which carried out the peeling process used in preparation of said polarizing film with an adhesive layer can be used as a separator of the polarizing film with an adhesive layer as it is, and can simplify in a process surface.
また、前記粘着剤層付き偏光フィルムにおいて、粘着剤層の形成にあたっては、第2樹脂フィルムの表面に、アンカー層を形成したり、コロナ処理、プラズマ処理等の各種易接着処理を施した後に粘着剤層を形成することができる。また、粘着剤層の表面には易接着処理をおこなってもよい。 Further, in the polarizing film with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is formed after an anchor layer is formed on the surface of the second resin film, or after various easy adhesion treatments such as corona treatment and plasma treatment. An agent layer can be formed. Moreover, you may perform an easily bonding process on the surface of an adhesive layer.
粘着剤層の厚さは、特に限定されるものではなく、例えば、5~100μmであることが好ましく、10~50μmであることが好ましい。 The thickness of the pressure-sensitive adhesive layer is not particularly limited, and is preferably 5 to 100 μm, for example, and preferably 10 to 50 μm.
本発明の粘着剤層付き偏光フィルムは、偏光子の厚みが10μm以下の両面保護偏光フィルムを用いるため、粘着剤層付き偏光フィルム全体としても薄膜化することができる。粘着剤層付き偏光フィルムの厚みとしては、70μm以下とすることができる。 Since the polarizing film with the pressure-sensitive adhesive layer of the present invention uses a double-sided protective polarizing film with a polarizer thickness of 10 μm or less, the polarizing film with the pressure-sensitive adhesive layer as a whole can be thinned. The thickness of the polarizing film with the pressure-sensitive adhesive layer can be 70 μm or less.
本発明の粘着剤層付き偏光フィルムは、前記粘着剤層を介して、液晶セル等の画像表示セルに貼り付けることができる。特に、本発明の粘着剤層付き偏光フィルムは、液晶表示装置の視認側偏光フィルムとして好適に用いることができる。 The polarizing film with an adhesive layer of the present invention can be attached to an image display cell such as a liquid crystal cell through the adhesive layer. Especially the polarizing film with an adhesive layer of this invention can be used suitably as a visual recognition side polarizing film of a liquid crystal display device.
3.画像表示装置
本発明の画像表示装置は、前記粘着剤層付き偏光フィルムを有することを特徴とする。
3. Image display device The image display device of the present invention has the above-mentioned polarizing film with an adhesive layer.
本発明の画像表示装置は、本発明の粘着剤層付き偏光フィルムを含むものであればよく、その他の構成については、従来の画像表示装置と同様のものを挙げることができる。 The image display device of the present invention only needs to include the polarizing film with the pressure-sensitive adhesive layer of the present invention, and other configurations can be the same as those of the conventional image display device.
本発明の画像表示装置は、前記粘着剤層付き偏光フィルムを含むため、高い信頼性を有するものである。 Since the image display device of the present invention includes the polarizing film with the pressure-sensitive adhesive layer, it has high reliability.
以下に、実施例によって本発明を具体的に説明するが、本発明はこれら実施例によって限定されるものではない。なお、各例中の部及び%はいずれも重量基準である。 Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In addition, all the parts and% in each example are based on weight.
製造例1(偏光フィルム(1)の製造)
吸水率0.75%、Tg75℃の非晶質のイソフタル酸共重合ポリエチレンテレフタレート(IPA共重合PET)フィルム(厚み:100μm)基材の片面に、コロナ処理を施し、このコロナ処理面に、ポリビニルアルコール(重合度:4200、ケン化度:99.2モル%)及びアセトアセチル変性PVA(重合度:1200、アセトアセチル変性度:4.6%、ケン化度:99.0モル%以上、日本合成化学工業(株)製、商品名「ゴーセファイマーZ200」)を9:1の比で含む水溶液を25℃で塗布及び乾燥して、厚み11μmのPVA系樹脂層を形成し、積層体を作製した。
得られた積層体を、120℃のオーブン内で周速の異なるロール間で縦方向(長手方向)に2.0倍に自由端一軸延伸した(空中補助延伸処理)。
次いで、積層体を、液温30℃の不溶化浴(水100重量部に対して、ホウ酸を4重量部配合して得られたホウ酸水溶液)に30秒間浸漬させた(不溶化処理)。
次いで、液温30℃の染色浴に、偏光板が所定の透過率となるようにヨウ素濃度、浸漬時間を調整しながら浸漬させた。本実施例では、水100重量部に対して、ヨウ素を0.2重量部配合し、ヨウ化カリウムを1.0重量部配合して得られたヨウ素水溶液に60秒間浸漬させた(染色処理)。
次いで、液温30℃の架橋浴(水100重量部に対して、ヨウ化カリウムを3重量部配合し、ホウ酸を3重量部配合して得られたホウ酸水溶液)に30秒間浸漬させた(架橋処理)。
その後、積層体を、液温70℃のホウ酸水溶液(水100重量部に対して、ホウ酸を4.5重量部配合し、ヨウ化カリウムを5重量部配合して得られた水溶液)に浸漬させながら、周速の異なるロール間で縦方向(長手方向)に総延伸倍率が5.5倍となるように一軸延伸を行った(水中延伸処理)。
その後、積層体を液温30℃の洗浄浴(水100重量部に対して、ヨウ化カリウムを4重量部配合して得られた水溶液)に浸漬させた(洗浄処理)。
以上により、厚み5μmの偏光子を含む光学フィルム積層体を得た。得られた偏光子のホウ酸含有量は、20重量%であった。
Production Example 1 (Production of Polarizing Film (1))
One side of an amorphous isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film (thickness: 100 μm) having a water absorption of 0.75% and Tg of 75 ° C. is subjected to corona treatment. Alcohol (degree of polymerization: 4200, degree of saponification: 99.2 mol%) and acetoacetyl-modified PVA (degree of polymerization: 1200, degree of acetoacetyl modification: 4.6%, degree of saponification: 99.0 mol% or more, Japan An aqueous solution containing 9: 1 ratio of synthetic chemical industry (trade name “Gosefimer Z200”) is applied and dried at 25 ° C. to form a PVA resin layer having a thickness of 11 μm. Produced.
The obtained laminate was uniaxially stretched in the longitudinal direction (longitudinal direction) 2.0 times between rolls having different peripheral speeds in an oven at 120 ° C. (air-assisted stretching process).
Next, the laminate was immersed in an insolubilization bath (a boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with respect to 100 parts by weight of water) for 30 seconds (insolubilization treatment).
Subsequently, it was immersed in a dyeing bath having a liquid temperature of 30 ° C. while adjusting the iodine concentration and the immersion time so that the polarizing plate had a predetermined transmittance. In this example, 0.2 parts by weight of iodine was blended with 100 parts by weight of water, and immersed in an aqueous iodine solution obtained by blending 1.0 part by weight of potassium iodide (dyeing treatment). .
Subsequently, it was immersed for 30 seconds in a crosslinking bath having a liquid temperature of 30 ° C. (a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with respect to 100 parts by weight of water). (Crosslinking treatment).
Thereafter, the laminated body was added to a boric acid aqueous solution having a liquid temperature of 70 ° C. (an aqueous solution obtained by adding 4.5 parts by weight of boric acid and 5 parts by weight of potassium iodide to 100 parts by weight of water). While being immersed, uniaxial stretching was performed in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds so that the total stretching ratio was 5.5 times (in-water stretching treatment).
Thereafter, the laminate was immersed in a cleaning bath (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 30 ° C. (cleaning treatment).
As a result, an optical film laminate including a polarizer having a thickness of 5 μm was obtained. The obtained polarizer had a boric acid content of 20% by weight.
(透明保護フィルムに適用する接着剤の作製)
N-ヒドロキシエチルアクリルアミド(HEAA)40重量部とアクリロイルモルホリン(ACMO)60重量部と光開始剤「IRGACURE 819」(BASF社製)3重量部を混合し、紫外線硬化型接着剤を調製した。
(Preparation of adhesive to be applied to transparent protective film)
An ultraviolet curable 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).
上記光学フィルム積層体の偏光子(厚み:5μm)の表面に、上記紫外線硬化型接着剤を硬化後の接着剤層の厚さが0.1μmになるように塗布しながら、視認側透明保護フィルム(第1樹脂フィルム)(厚さ27μmのシクロオレフィン系フィルム(商品名:ZF12-025-1300UHC、日本ゼオン(株)製)、40℃、92%R.H.における透湿度:17g/(m2・day)、線膨張係数:6×10-5/K、寸法変化率:-0.33%、破断強度:13N)を貼合せたのち、活性エネルギー線として、紫外線を照射し、接着剤を硬化させた。紫外線照射は、ガリウム封入メタルハライドランプ、照射装置:Fusion UV Systems,Inc社製のLight HAMMER10、バルブ:Vバルブ、ピーク照度:1600mW/cm2、積算照射量1000/mJ/cm2(波長380~440nm)を使用し、紫外線の照度は、Solatell社製のSola-Checkシステムを使用して測定した。次いで、非晶性PET基材を剥離して、剥離した面に、上記紫外線硬化型接着剤を硬化後の接着剤層の厚さが0.1μmになるように塗布しながら、事前にコロナ処理した画像表示セル側透明保護フィルム(第2樹脂フィルム)(厚さ13μmのシクロオレフィン系フィルム(商品名:ZF-014-1330、日本ゼオン(株)製)、40℃、92%R.H.における透湿度:12g/(m2・day)、線膨張係数:7.1×10-5/K、寸法変化率:-0.01%、破断強度:9N)を貼合せたのち、上記と同様に紫外線を照射し、接着剤を硬化させ、薄型偏光子を用いた両面保護偏光フィルム(1)を作製した。
While applying the UV curable adhesive to the surface of the polarizer (thickness: 5 μm) of the optical film laminate so that the thickness of the adhesive layer after curing is 0.1 μm, the viewing-side transparent protective film (First resin film) (Cycloolefin film having a thickness of 27 μm (trade name: ZF12-025-1300UHC, manufactured by Nippon Zeon Co., Ltd.), moisture permeability at 40 ° C., 92% RH: 17 g / (m 2 · day), linear expansion coefficient: 6 × 10 −5 / K, dimensional change rate: −0.33%, breaking strength: 13 N), and then irradiated with ultraviolet rays as active energy rays, adhesive Was cured. Ultraviolet irradiation is performed using a gallium-encapsulated metal halide lamp, an irradiation device: Fusion UV Systems, Inc.
製造例2(偏光フィルム(2)の製造)
製造例1で得られた光学フィルム積層体の偏光子(厚み:5μm)の表面に、実施例1で製造した紫外線硬化型接着剤を硬化後の接着剤層の厚さが0.1μmになるように塗布しながら、視認側透明保護フィルム(厚さ27μmのシクロオレフィン系フィルム(商品名:ZD12-099063-C1300UHC、日本ゼオン(株)製)、40℃、92%R.H.における透湿度:24g/(m2・day)、線膨張係数:6.3×10-5/K、寸法変化率:-0.28%、破断強度:20N)を貼合せたのち、活性エネルギー線として、紫外線を照射し、接着剤を硬化させた。紫外線照射は、ガリウム封入メタルハライドランプ、照射装置:Fusion UVSystems,Inc社製のLight HAMMER10、バルブ:Vバルブ、ピーク照度:1600mW/cm2、積算照射量1000/mJ/cm2(波長380~440nm)を使用し、紫外線の照度は、Solatell社製のSola-Checkシステムを使用して測定した。次いで、非晶性PET基材を剥離して、剥離した面に、実施例1で製造した紫外線硬化型接着剤を硬化後の接着剤層の厚さが0.1μmになるように塗布しながら、画像表示セル側透明保護フィルム(厚さ13μmのシクロオレフィン系フィルム(商品名:ZF-014-1330、日本ゼオン(株)製)、40℃、92%R.H.における透湿度:12g/(m2・day)、線膨張係数:7.1×10-5/K、寸法変化率:-0.01%、破断強度:9N)を貼合せたのち、上記と同様に紫外線を照射し、接着剤を硬化させ、薄型偏光子を用いた両面保護偏光フィルム(2)を作製した。
Production Example 2 (Production of Polarizing Film (2))
On the surface of the polarizer (thickness: 5 μm) of the optical film laminate obtained in Production Example 1, the thickness of the adhesive layer after curing the ultraviolet curable adhesive produced in Example 1 becomes 0.1 μm. The transparent side protective film (27 μm thick cycloolefin film (trade name: ZD12-099063-C1300UHC, manufactured by Nippon Zeon Co., Ltd.), moisture permeability at 40 ° C., 92% RH : 24 g / (m 2 · day), linear expansion coefficient: 6.3 × 10 −5 / K, dimensional change rate: −0.28%, breaking strength: 20 N) The adhesive was cured by irradiating with ultraviolet rays. UV irradiation is performed using a gallium-filled metal halide lamp, irradiation device: Fusion UVSystems, Inc.
製造例3(偏光フィルム(3)の製造)
製造例1で得られた光学フィルム積層体の偏光子(厚み:5μm)の表面に、接着剤層の厚さが0.1μmになるようにポリビニルアルコール系接着剤を塗布しながら、視認側透明保護フィルム(厚さ40μmのアクリル系フィルム(商品名:HX-40UC-1330、(株)カネカ製)、40℃、92%R.H.における透湿度:70g/(m2・day)、線膨張係数:4.3×10-5/K、寸法変化率:-0.5%、破断強度:39N)を貼合せたのち、50℃で5分間の乾燥を行った。次いで、非晶性PET基材を剥離して、剥離した面に、接着剤層の厚さが0.1μmになるようにポリビニルアルコール系接着剤を塗布しながら、画像表示セル側透明保護フィルム(厚さ20μmのアクリル系フィルム(商品名:RV-20UB-1330、東洋鋼鈑(株)製)、40℃、92%R.H.における透湿度:170g/(m2・day)、線膨張係数:5.6×10-5/K、寸法変化率:-0.35%、破断強度:19N)を貼合せたのち、50℃で5分間の乾燥を行い、薄型偏光子を用いた両面保護偏光フィルム(3)を作製した。
Production Example 3 (Production of Polarizing Film (3))
While applying a polyvinyl alcohol-based adhesive on the surface of the polarizer (thickness: 5 μm) of the optical film laminate obtained in Production Example 1 so that the thickness of the adhesive layer is 0.1 μm, the viewing side is transparent. Protective film (Acrylic film having a thickness of 40 μm (trade name: HX-40UC-1330, manufactured by Kaneka Corporation), moisture permeability at 40 ° C., 92% RH: 70 g / (m 2 · day), wire (Expansion coefficient: 4.3 × 10 −5 / K, dimensional change rate: −0.5%, breaking strength: 39 N), and then drying at 50 ° C. for 5 minutes. Next, the amorphous PET base material was peeled off, and the image display cell side transparent protective film (with the polyvinyl alcohol adhesive applied to the peeled surface so that the thickness of the adhesive layer was 0.1 μm ( Acrylic film having a thickness of 20 μm (trade name: RV-20UB-1330, manufactured by Toyo Kohan Co., Ltd.), moisture permeability at 40 ° C. and 92% RH: 170 g / (m 2 · day), linear expansion After bonding the coefficient: 5.6 × 10 −5 / K, dimensional change rate: −0.35%, breaking strength: 19 N), drying at 50 ° C. for 5 minutes, and both sides using a thin polarizer A protective polarizing film (3) was produced.
実施例1
製造例1で得られた両面保護偏光フィルム(1)の視認側保護フィルム上に、粘着剤シート(厚さ:150μm、日東電工(株)製の粘着シートである「LUCIACS」(商品名))を貼付して粘着剤層を形成し、当該粘着剤層上に保護板(厚さ500μmのカバーガラス、線膨張係数:8×10-6/K、鉛筆硬度:10H、比重:2.5、熱伝導率:1W/(m・K))を積層し、保護板付き偏光フィルムを形成した。
Example 1
On the viewing-side protective film of the double-sided protective polarizing film (1) obtained in Production Example 1, an adhesive sheet (thickness: 150 μm, “LUCIACS” (trade name), which is an adhesive sheet manufactured by Nitto Denko Corporation) To form a pressure-sensitive adhesive layer, and a protective plate (500 μm thick cover glass, linear expansion coefficient: 8 × 10 −6 / K, pencil hardness: 10H, specific gravity: 2.5, Thermal conductivity: 1 W / (m · K)) was laminated to form a polarizing film with a protective plate.
実施例2
製造例2で得られた両面保護偏光フィルム(2)を用いる以外は、実施例1と同様にして、保護板付き偏光フィルムを形成した。
Example 2
A polarizing film with a protective plate was formed in the same manner as in Example 1 except that the double-sided protective polarizing film (2) obtained in Production Example 2 was used.
比較例1~3
比較例1~3においては、製造例1~3で得られた両面保護偏光フィルム(1)~(3)をそのまま用いた(保護板の積層なし)。
Comparative Examples 1 to 3
In Comparative Examples 1 to 3, the double-sided protective polarizing films (1) to (3) obtained in Production Examples 1 to 3 were used as they were (no protective plate was laminated).
実施例、比較例で使用した保護フィルムの透湿度、保護フィルム及び保護板の線膨張係数、実施例で得られた保護フィルム付き偏光フィルム、比較例で使用した偏光フィルムの寸法変化率、及び貫通クラックの発生については、以下の方法で測定した。 Example, moisture permeability of protective film used in comparative example, linear expansion coefficient of protective film and protective plate, polarizing film with protective film obtained in example, dimensional change rate of polarizing film used in comparative example, and penetration The occurrence of cracks was measured by the following method.
<透明保護フィルムの透湿度>
透湿度の測定は、JIS Z0208の透湿度試験(カップ法)に準じて測定した。直径6cmに切断したサンプルを約15gの塩化カルシウムを入れた透湿カップ(開口径:直径6cm)にセットし、温度40℃、湿度92%R.H.の恒温機に入れ、24時間放置した前後の塩化カルシウムの重量増加を測定することで透湿度(g/(m2・day)を求めた。
<Water vapor permeability of transparent protective film>
The moisture permeability was measured according to a moisture permeability test (cup method) of JIS Z0208. A sample cut to a diameter of 6 cm was set in a moisture permeable cup (opening diameter:
<寸法変化率>
実施例及び比較例で用いた両面保護偏光フィルムを100mm×100mm(偏光子の吸収軸方向が100mm)の大きさにカットしたサンプルを調製した。当該サンプルを、50℃、0.5MPaで、15分間のオートクレーブ処理を行って、オートクレーブから取り出し、室温(23℃)の環境下で24時間放置した。その後、85℃のオーブンに120時間投入した。オーブンから取り出し後、サンプルから保護フィルムを剥離し、それぞれの保護フィルムについて、非接触式二次元画像解析装置(商品名:QVA606L1L-C、(株)ミツトヨ製)を用いて、各保護フィルムの長さを測定した。処理前後の測定値から、寸法変化率を下記式に基づき算出した。
寸法変化率(%)={(L0-L1)/L1}×100
L0:初期の保護フィルムの、偏光子の吸収軸に直交する方向における長さ(100mm)
L1:加熱環境下放置後の保護フィルムの、偏光子の吸収軸に直交する方向における長さ
<Dimensional change rate>
A sample was prepared by cutting the double-sided protective polarizing film used in Examples and Comparative Examples into a size of 100 mm × 100 mm (absorption axis direction of polarizer is 100 mm). The sample was autoclaved at 50 ° C. and 0.5 MPa for 15 minutes, removed from the autoclave, and allowed to stand for 24 hours in an environment at room temperature (23 ° C.). Thereafter, it was put into an oven at 85 ° C. for 120 hours. After taking out from the oven, the protective film is peeled off from the sample, and for each protective film, the length of each protective film is measured using a non-contact type two-dimensional image analyzer (trade name: QVA606L1L-C, manufactured by Mitutoyo Corporation). Was measured. From the measured values before and after the treatment, the dimensional change rate was calculated based on the following formula.
Dimensional change rate (%) = {(L 0 −L 1 ) / L 1 } × 100
L 0 : Length of initial protective film in a direction perpendicular to the absorption axis of the polarizer (100 mm)
L 1 : Length of the protective film after standing in a heating environment in a direction perpendicular to the absorption axis of the polarizer
<線膨張係数の測定>
線膨張係数の測定は、熱機械分析装置(製品名:TMA7100、(株)日立ハイテクサイエンス製)を用いて行った。具体的には、実施例、比較例で用いた保護フィルムからサンプル(長さ20mm×幅5mm)切り出し、サンプルを引っ張り測定用治具にセットし、引張荷重20mN、昇温速度、10℃/分、-40℃~85℃を4サイクル(ヒートショック条件)の条件下で測定し、線膨張係数を得た。なお、線膨張係数の測定は、偏光子の吸収軸に直交する方向で測定した。
<Measurement of linear expansion coefficient>
The linear expansion coefficient was measured using a thermomechanical analyzer (product name: TMA7100, manufactured by Hitachi High-Tech Science Co., Ltd.). Specifically, a sample (length 20 mm ×
<破断強度の測定>
実施例及び比較例で使用した保護フィルムを100mm×100mmに切断した後、引張試験機として、オートグラフ(製品名:AG-IS、(株)島津製作所製)を用い、試験サンプルに対し、引張速度300mm/min、チャック間距離100mm、室温(23℃)で引張試験を行い、応力-歪み曲線を求めた。保護フィルムが破断したときの応力を求めて破断強度とした。なお、破断強度の測定は、偏光子の吸収軸に直交する方向で測定した。
<Measurement of breaking strength>
After the protective films used in Examples and Comparative Examples were cut to 100 mm × 100 mm, an autograph (product name: AG-IS, manufactured by Shimadzu Corporation) was used as a tensile tester, and the test sample was pulled. A tensile test was performed at a speed of 300 mm / min, a distance between chucks of 100 mm, and room temperature (23 ° C.) to obtain a stress-strain curve. The stress at the time when the protective film broke was obtained and used as the breaking strength. The breaking strength was measured in a direction perpendicular to the absorption axis of the polarizer.
<偏光フィルムの偏光度変化(ΔP)の測定>
実施例及び比較例で得られた偏光フィルムを、85℃/85%R.H.の恒温恒湿機に500時間投入した。投入前と投入後の偏光フィルムの偏光度を、積分球付き分光光度計(日本分光(株)製のV7100)を用いて測定し、以下の式により偏光度の変化量ΔPを求めた。
偏光度の変化量ΔP(%)=(投入前の偏光度(%))-(投入後の偏光度(%))
なお、偏光度Pは、2枚の同じ偏光フィルムを両者の透過軸が平行となるように重ね合わせた場合の透過率(平行透過率:Tp)及び、両者の透過軸が直交するように重ね合わせた場合の透過率(直交透過率:Tc)を以下の式に適用することにより求められるものである。
偏光度P(%)={(Tp-Tc)/(Tp+Tc)}1/2×100
各透過率は、グランテラープリズム偏光子を通して得られた完全偏光を100%として、JIS Z8701の2度視野(C光源)により視感度補整したY値で示したものである。
<Measurement of change in polarization degree (ΔP) of polarizing film>
The polarizing films obtained in Examples and Comparative Examples were subjected to 85 ° C./85% R.D. H. For 500 hours. The polarization degree of the polarizing film before and after the addition was measured using a spectrophotometer with an integrating sphere (V7100 manufactured by JASCO Corporation), and the amount of change ΔP in the polarization degree was determined by the following equation.
Change amount of polarization degree ΔP (%) = (Polarization degree before injection (%)) − (Polarization degree after introduction (%))
The degree of polarization P is the transmittance when two identical polarizing films are overlapped so that their transmission axes are parallel (parallel transmittance: Tp), and they are overlapped so that their transmission axes are orthogonal to each other. It is calculated | required by applying the transmittance | permeability (orthogonal transmittance | permeability: Tc) at the time of combining to the following formula | equation.
Polarization degree P (%) = {(Tp−Tc) / (Tp + Tc)} 1/2 × 100
Each transmittance is represented by a Y value obtained by correcting visibility with a two-degree field of view (C light source) of JIS Z8701, with 100% of the completely polarized light obtained through the Granteller prism polarizer.
<貫通クラックの確認:ヒートショック試験>
実施例及び比較例で得られた両面保護偏光フィルムの画像表示セル側透明保護フィルム側に粘着剤層を設けて、粘着剤層付偏光フィルムを調製した。粘着剤層付偏光フィルムを、50mm×150mm(吸収軸方向が50mm)に裁断し、0.5mm厚の無アルカリガラスに貼り合せてサンプルを作製した。当該サンプルを、-40~85℃のヒートショックを各30分間×100回の環境下に投入した後に、取り出して偏光フィルムに貫通クラック(本数)が発生しているか否かを目視にて確認した。この試験を10回行った。
<Confirmation of penetration crack: heat shock test>
A pressure-sensitive adhesive layer was provided on the image display cell side transparent protective film side of the double-sided protective polarizing film obtained in Examples and Comparative Examples to prepare a polarizing film with a pressure-sensitive adhesive layer. The polarizing film with a pressure-sensitive adhesive layer was cut into 50 mm × 150 mm (absorption axis direction was 50 mm), and bonded to 0.5 mm-thick alkali-free glass to prepare a sample. The sample was subjected to a heat shock of −40 to 85 ° C. for 30 minutes × 100 times in each environment, and then taken out, and it was visually confirmed whether or not there were through cracks (number) in the polarizing film. . This test was performed 10 times.
1 偏光フィルム
2 偏光子
3 第1樹脂フィルム
4 第2樹脂フィルム
5 保護板
6 粘着剤層
10 粘着剤層付き偏光フィルム
DESCRIPTION OF
Claims (9)
前記第1樹脂フィルム及び第2樹脂フィルムの透湿度が、いずれも30g/(m2・day)以下であり、
前記第1樹脂フィルムの前記偏光子を有する側とは反対側の面に保護板を有することを特徴とする偏光フィルム。 A polarizing film having a first resin film on one surface of a polarizer having a thickness of 10 μm or less and a second resin film on the other surface,
The moisture permeability of the first resin film and the second resin film are both 30 g / (m 2 · day) or less,
A polarizing film having a protective plate on the surface of the first resin film opposite to the side having the polarizer.
An image display device comprising the polarizing film with the pressure-sensitive adhesive layer according to claim 8.
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| KR1020187031475A KR102095144B1 (en) | 2016-05-23 | 2017-05-22 | Polarizing film, adhesive layer-forming polarizing film, and image display device |
| CN201780030036.6A CN109154689B (en) | 2016-05-23 | 2017-05-22 | Polarizing film, polarizing film with adhesive layer, and image display device |
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| KR (1) | KR102095144B1 (en) |
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| WO2019188906A1 (en) * | 2018-03-30 | 2019-10-03 | 日東電工株式会社 | Method for manufacturing laminated film |
| CN113366353A (en) * | 2019-01-31 | 2021-09-07 | 日东电工株式会社 | Polyester film and polarizing plate comprising same |
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| WO2019131220A1 (en) * | 2017-12-28 | 2019-07-04 | 日東電工株式会社 | Polarization plate set and liquid crystal display panel |
| JP7288306B2 (en) | 2018-02-26 | 2023-06-07 | 日東電工株式会社 | POLARIZING FILM AND MANUFACTURING METHOD THEREOF, OPTICAL FILM AND IMAGE DISPLAY DEVICE |
| JP2019219525A (en) * | 2018-06-20 | 2019-12-26 | 日東電工株式会社 | Polarizing film, polarizing film with adhesive layer, and image display device |
| KR102275734B1 (en) | 2018-09-21 | 2021-07-08 | 주식회사 엘지화학 | Liquid crystal display |
| JP7331347B2 (en) * | 2018-10-26 | 2023-08-23 | 住友化学株式会社 | Polarizing plate and display device |
| KR20210097721A (en) * | 2018-12-07 | 2021-08-09 | 스미또모 가가꾸 가부시키가이샤 | Polarizer and display device |
| JP7397605B2 (en) * | 2019-09-12 | 2023-12-13 | 住友化学株式会社 | Manufacturing method of polarizing plate |
| JP7382264B2 (en) * | 2020-03-27 | 2023-11-16 | 日東電工株式会社 | Polarizing film and image display device |
| JP7633792B2 (en) * | 2020-10-09 | 2025-02-20 | 日東電工株式会社 | Method for manufacturing a polarizing plate with a retardation layer |
| JP7654956B2 (en) * | 2020-10-29 | 2025-04-02 | 日本ゼオン株式会社 | Manufacturing method of polarizing plate |
| TWI854170B (en) * | 2021-11-23 | 2024-09-01 | 住華科技股份有限公司 | Optical film and display device formed therefrom and evaluation method of resistance to polarizer cracking for optical film |
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| CN113366353A (en) * | 2019-01-31 | 2021-09-07 | 日东电工株式会社 | Polyester film and polarizing plate comprising same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6741477B2 (en) | 2020-08-19 |
| JP2017211433A (en) | 2017-11-30 |
| KR102095144B1 (en) | 2020-03-30 |
| KR20180123577A (en) | 2018-11-16 |
| CN109154689A (en) | 2019-01-04 |
| TWI730098B (en) | 2021-06-11 |
| CN109154689B (en) | 2021-06-18 |
| TW201743087A (en) | 2017-12-16 |
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