WO2024116892A1 - Stratifié, et dispositif d'affichage - Google Patents

Stratifié, et dispositif d'affichage Download PDF

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Publication number
WO2024116892A1
WO2024116892A1 PCT/JP2023/041404 JP2023041404W WO2024116892A1 WO 2024116892 A1 WO2024116892 A1 WO 2024116892A1 JP 2023041404 W JP2023041404 W JP 2023041404W WO 2024116892 A1 WO2024116892 A1 WO 2024116892A1
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Prior art keywords
optical film
range
acrylate
meth
film
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PCT/JP2023/041404
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English (en)
Japanese (ja)
Inventor
奈々恵 藤枝
啓人 小長
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コニカミノルタ株式会社
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Publication of WO2024116892A1 publication Critical patent/WO2024116892A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
    • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
    • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • B32B7/023—Optical properties
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/11—Anti-reflection coatings
    • G02B1/111—Anti-reflection coatings using layers comprising organic materials
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/22—Absorbing filters
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements

Definitions

  • the present invention relates to a laminate and a display device. More specifically, the present invention relates to a laminate that achieves both suppression of external light reflection and good contrast after bending.
  • Flexible displays consist of a display unit and a cover unit that protects the display unit.
  • the substrate used in the cover unit is required to have flexibility. Therefore, it has been considered to change the conventionally used glass substrate to a resin substrate or to make the glass substrate itself thinner.
  • thin-film glass Ultra Thin Glass: UTG
  • UTG Ultra Thin Glass
  • a technique is known in which a protective film is attached to the thin film glass to improve impact resistance when used in a cover unit.
  • displays have a problem with external light reflection. More specifically, external light passes through the cover unit and is reflected on the surface of the metal substrate in the display unit, and the reflected light is perceived by the viewer, which makes it difficult to correctly view images and videos displayed on the display.
  • Two possible methods for solving this problem are: 1) weakening the intensity of external light that reaches the metal substrate in the display unit, and 2) weakening the intensity of light reflected from the surface of the metal substrate before it is visually recognized. In other words, it is preferable to weaken the intensity of external light that passes through the cover unit and the intensity of reflected light that passes through the cover unit and is visually recognized, and a method of imparting optical properties to the protective film is being considered.
  • Patent Document 1 proposes a self-luminous display device that suppresses scattering of light reflected from the substrate and simplifies the layer structure by making the sealing material placed on the substrate on which the light-emitting elements are mounted black.
  • this technology is related to the sealing material, and not to the film that protects the thin glass. Furthermore, this technology does not sufficiently suppress external light reflection, and further improvements are required.
  • the present invention was made in consideration of the above problems and circumstances, and the problem to be solved is to provide a laminate and a display device that achieve both suppression of external light reflection and good contrast after bending.
  • the present inventors have investigated the causes of the above problems in order to solve the above problems, and have found that, in a laminate having at least an optical film A, an optical film B, and a glass layer, a laminate can be provided which achieves both suppression of external light reflection and good contrast after bending by arranging the optical film A, the glass layer, and the optical film B in this order, setting the average light transmittances T A and T B of the optical film A and the optical film B in the wavelength region of 380 to 780 nm within specific ranges, and making T A larger than T B , thereby completing the present invention. That is, the above-mentioned problems of the present invention are solved by the following means.
  • the T A and the T B satisfy the following formula (1) and both the T A and the T B are within a range of 39 to 89%.
  • a laminate comprising:
  • the laminate further has an adhesive layer C,
  • the optical film A, the glass layer, the optical film B, and the adhesive layer C are arranged in this order,
  • T C the average light transmittance of the adhesive layer C in the wavelength region of 380 to 780 nm
  • T B and the T C satisfy the following formula (2): T B ⁇ T C 3.
  • the laminate further has an adhesive layer D, The optical film A, the glass layer, the adhesive layer D, and the optical film B are arranged in this order, 3.
  • a display device comprising the laminate according to claim 1 or 2.
  • the above-mentioned means of the present invention make it possible to provide a laminate and a display device that achieve both suppression of external light reflection and good contrast after bending.
  • the laminate of the present invention is a laminate having an optical film and thin glass (glass layer), and is configured such that the optical film is bonded to both sides of the thin glass. It is believed that this configuration can protect the thin glass, which is vulnerable to impacts and easily breaks.
  • the intensity of light that reaches (is incident on) the surface of the thin glass can be weakened by lowering the average light transmittance (hereinafter simply referred to as "light transmittance") of optical film A in the wavelength range of 380 to 780 nm.
  • the intensity of light that reaches the surface of the metal substrate can be weakened by lowering the light transmittance of optical film A and optical film B. Therefore, by making the light transmittance of optical film A and optical film B relatively low, specifically, 89% or less, it is possible to suppress external light reflection on the thin glass and metal substrate.
  • optical film A is disposed on the most visible side, the intensity of light that reaches (enters) the surface of optical film A cannot be weakened. For this reason, the intensity of reflected light can be weakened by relatively increasing the light transmittance of optical film A. Therefore, by making the light transmittance of optical film A higher than that of optical film B, external light reflection at optical film A and thin glass can be efficiently suppressed. However, when the external light transmitted through optical film A reaches the metal substrate, the visibility is deteriorated due to the reflection of the external light from the metal substrate.
  • the transmittance of optical film B which is closer to the metal substrate, is made lower than the transmittance of optical film A, thereby making it possible to efficiently suppress the reflection of the external light on the metal substrate.
  • optical film A and optical film B are made too low, the light from the light-emitting elements in the display unit cannot be sufficiently transmitted to the viewing side. Therefore, by allowing optical film A and optical film B to transmit light appropriately, good contrast can be obtained in the display device.
  • the laminate of the present invention is used in a foldable display device (flexible display), it is necessary that the display device obtain good contrast even after repeated folding (bending).
  • the inventors found that by setting the light transmittance of optical film A and optical film B to 39% or more, good contrast can be obtained even in the display device after repeated folding.
  • 1 is a cross-sectional view of a basic layer structure of a laminate of the present invention.
  • 1 is a cross-sectional view of a basic layer structure of a laminate of the present invention.
  • 1 is a cross-sectional view of a basic layer structure of a laminate of the present invention.
  • Schematic diagram showing an example of a method for producing thin glass An example of application of the present invention to an organic EL display, which is an example of a display device.
  • An example of application of the present invention to an organic EL display which is an example of a display device.
  • the laminate of the present invention is a laminate having at least an optical film A, an optical film B, and a glass layer, and is arranged in the order of the optical film A, the glass layer, and the optical film B, and is characterized in that, when the average light transmittances of the optical film A and the optical film B in a wavelength region of 380 to 780 nm are T A and T B , respectively, the T A and the T B satisfy the following formula (1) and both the T A and the T B are within the range of 39 to 89%.
  • the T A is preferably within the range of 70 to 85%.
  • the T B is preferably within the range of 70 to 85%.
  • At least the optical film B contains rubber particles.
  • the content of the rubber particles is within the range of 10 to 80 mass % relative to the total mass of the optical film B.
  • the optical film B contains a thermoplastic (meth)acrylic resin.
  • the thickness of the optical film B is within the range of 15 to 50 ⁇ m.
  • the thickness of the glass layer is within the range of 10 to 30 ⁇ m.
  • the laminate further has an adhesive layer C, and is arranged in the order of the optical film A, the glass layer, the optical film B, and the adhesive layer C, and when the average light transmittance of the adhesive layer C in a wavelength region of 380 to 780 nm is T C , the T B and the T C satisfy the following formula (2). Equation (2): TB ⁇ TC
  • the laminate further includes an adhesive layer D, and that the optical film A, the glass layer, the adhesive layer D, and the optical film B are arranged in this order, and that the storage modulus of the adhesive layer D at 25°C is within the range of 0.5 to 8 MPa.
  • the display device of the present invention is characterized by comprising the laminate of the present invention.
  • the optical film A is disposed closer to the viewing side of the display device than the optical film B.
  • the laminate of the present invention is a laminate having at least an optical film A, an optical film B, and a glass layer, which is arranged in the order of the optical film A, the glass layer, and the optical film B, and is characterized in that, when the average light transmittances of the optical film A and the optical film B in a wavelength region of 380 to 780 nm are T A and T B , respectively, the T A and the T B satisfy the following formula (1) and both the T A and the T B are within the range of 39 to 89%.
  • optical film refers to a film that has an optical function in which, as one of several functions of the film, the average light transmittance in the wavelength range of 380 to 780 nm is within the range of 39 to 89%.
  • the laminate 10 has an optical film A1, a glass layer 3, and an optical film B2.
  • 2 and 3 are cross-sectional views of the basic layer structure of the laminate of the present invention when an adhesive layer is included.
  • the laminate 20 includes an optical film A1, a glass layer 3, an optical film B2, and an adhesive layer C4.
  • the laminate 30 includes an optical film A1, a glass layer 3, an adhesive layer D5, an optical film B2, and an adhesive layer C4.
  • the boundary between the adhesive layer C4 and the optical film B2 does not necessarily have to be clear, and the adhesive layer C4 and the optical film B2 may be integrated into a layer structure.
  • the boundary between the adhesive layer D5 and the optical film B2 does not necessarily have to be clear, and the adhesive layer D5 and the optical film B2 may be integrated into a layer structure.
  • both sides of the thin glass (glass layer) are protected with an optical film, and the optical transmittance of the optical film is set within a specific range. This makes it possible to achieve both suppression of external light reflection and good contrast after bending when the laminate of the present invention is used as a cover unit.
  • the laminate of the present invention has at least an optical film A, an optical film B, and a glass layer. If necessary, it may have an adhesive layer or the like.
  • the adhesive layer is preferably an adhesive layer C or an adhesive layer D described later, but is not particularly limited. Each layer will be described below.
  • Optical Film A and optical film B according to the present invention are characterized in that, when average light transmittances in a wavelength region of 380 to 780 nm are T A and T B , respectively, T A and T B satisfy the following formula (1) and both T A and T B are within the range of 39 to 89%.
  • optical film A and optical film B may or may not be the same.
  • the light transmittance of an optical film can be adjusted by adding a colorant to the optical film. It can also be adjusted by the type and content of the materials (resin, rubber particles, etc.) that make up the optical film.
  • the optical film according to the present invention is preferably made of a resin, and further preferably contains rubber particles, a colorant, fine particles, etc., as necessary.
  • Resin for Optical Film is not particularly limited, and examples thereof include cellulose ester, cycloolefin-based resin, fumaric acid diester-based resin, polypropylene, (meth)acrylic resin, polyester, polyarylate, polyimide, styrene-based resin, and composite resin thereof.
  • a linear polymer material having a carbonyl group in the side chain or a polymer material having a cyclic structure in the main chain.
  • a (meth)acrylic resin, a styrene-(meth)acrylate copolymer, a cycloolefin resin, a polyimide, or a cellulose ester it is preferable to contain a linear polymer material having a carbonyl group in the side chain, or a polymer material having a cyclic structure in the main chain.
  • a (meth)acrylic resin a styrene-(meth)acrylate copolymer, a cycloolefin resin, a polyimide, or a cellulose ester.
  • the (meth)acrylic resin preferably has at least a structural unit (U1) derived from methyl methacrylate.
  • the thermoplastic (meth)acrylic resin preferably further has a structural unit (U2) derived from phenylmaleimide.
  • the (meth)acrylic resin may further have structural units other than those described above. From the viewpoint of imparting toughness to the optical film, it is more preferable that the (meth)acrylic resin further has a structural unit (U3) derived from an alkyl acrylate ester.
  • thermoplastic (meth)acrylic resin preferably has a structural unit (U1) derived from methyl methacrylate, a structural unit (U2) derived from phenylmaleimide, and a structural unit (U3) derived from an alkyl acrylate.
  • the content of the structural unit (U1) derived from methyl methacrylate is preferably within the range of 50 to 95% by mass, and more preferably within the range of 70 to 90% by mass, relative to all structural units constituting the (meth)acrylic resin.
  • the structural unit (U2) derived from phenylmaleimide has a relatively rigid structure, and therefore can increase the mechanical strength of the optical film.
  • the structural unit (U2) derived from phenylmaleimide has a relatively bulky structure, that is, it has microscopic voids in the resin matrix through which the rubber particles can move. This makes it easier to concentrate the rubber particles in the surface layer of the optical film. The rubber particles will be described in more detail later.
  • the content of the structural unit (U2) derived from phenylmaleimide is preferably within a range of 1 to 25 mass%, and more preferably within a range of 7 to 15 mass%, based on all structural units constituting the (meth)acrylic resin.
  • the content of the structural unit (U2) derived from phenylmaleimide is 1% by mass or more, the optical film has excellent storage stability in a high humidity environment, and when the content is 25% by mass or less, the optical film can have sufficient toughness.
  • the structural unit (U3) derived from an alkyl acrylate ester can impart moderate flexibility to the resin. Therefore, for example, by combining it with the structural unit (U2) derived from phenylmaleimide, sufficient toughness can be imparted to the optical film.
  • the alkyl acrylate is preferably an alkyl acrylate having 1 to 7 carbon atoms, and more preferably 1 to 5 carbon atoms in the alkyl portion.
  • acrylic acid alkyl esters include methyl acrylate (methyl acrylate), ethyl acrylate (ethyl acrylate), propyl acrylate (propyl acrylate), butyl acrylate (butyl acrylate), 2-hydroxyethyl acrylate (2-hydroxyethyl acrylate), hexyl acrylate (hexyl acrylate), and 2-ethylhexyl acrylate (2-ethylhexyl acrylate).
  • the content of the structural unit (U3) derived from an alkyl acrylate is preferably within a range of 1 to 25 mass%, and more preferably within a range of 5 to 15 mass%, based on all structural units constituting the (meth)acrylic resin.
  • the content of the structural unit (U3) derived from an alkyl acrylate of 1% by mass or more can provide the (meth)acrylic resin with appropriate flexibility and can suppress breakage of the optical film, while the content of the structural unit (U3) derived from an alkyl acrylate of 25% by mass or less can suppress a decrease in the glass transition temperature (Tg) of the (meth)acrylic resin and can provide the optical film with excellent storage stability under high humidity conditions.
  • Tg glass transition temperature
  • the ratio of the structural unit (U2) derived from phenylmaleimide to the total amount of the structural unit (U2) derived from phenylmaleimide and the structural unit (U3) derived from an alkyl acrylate is preferably within the range of 20 to 70% by mass. When this ratio is 20% by mass or more, it is easy to increase the storage modulus of the optical film, and when it is 70% by mass or less, sufficient toughness can be imparted to the optical film.
  • the glass transition temperature (Tg) of the (meth)acrylic resin is preferably 100°C or higher, and more preferably within the range of 120 to 150°C. By keeping it within the above range, the heat resistance of the optical film can be improved.
  • Tg of the (meth)acrylic resin it is preferable to adjust the content of, for example, the structural unit (U2) derived from phenylmaleimide or the structural unit (U3) derived from an alkyl acrylate.
  • the weight-average molecular weight (Mw) of the (meth)acrylic resin is preferably 100,000 or more, more preferably 1,000,000 or more, and even more preferably in the range of 1,500,000 to 3,000,000.
  • the toughness of the optical film can be increased. This makes it possible to prevent the optical film from breaking due to the transport tension during transport.
  • the storage modulus of the optical film can be increased, making it possible to suppress winding deformation.
  • the weight average molecular weight (Mw) of the (meth)acrylic resin can be measured by the following method.
  • the weight average molecular weight (Mw) and number average molecular weight of other resins can also be measured by the following method.
  • Styrene-(meth)acrylate copolymer Styrene-acrylic resin is synthesized by addition polymerization of at least a styrene monomer and a (meth)acrylic acid ester monomer.
  • styrene-(meth)acrylate copolymers can impart transparency to optical films.
  • the moisture absorption expansion coefficient can be adjusted by the copolymerization ratio of the styrene portion, so curling of optical films and laminates can be controlled by adjusting the copolymerization ratio.
  • styrene monomer examples include styrene represented by the structural formula CH 2 ⁇ CH—C 6 H 5 , as well as styrene derivatives having a known side chain or functional group in the styrene structure.
  • Examples of the (meth)acrylic acid ester monomer include acrylic acid esters and methacrylic acid esters represented by CH(R 1 ) ⁇ CHCOOR 2 (R 1 represents a hydrogen atom or a methyl group, and R 2 represents an alkyl group having 1 to 24 carbon atoms).
  • Other examples include acrylic acid ester derivatives and methacrylic acid ester derivatives having known side chains or functional groups in the structure of these esters.
  • styrene monomers include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ⁇ -methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, and p-n-dodecylstyrene.
  • Examples of the (meth)acrylic acid ester monomer include acrylic acid ester monomers such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate (2EHA), stearyl acrylate, lauryl acrylate, and phenyl acrylate; and methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethyla
  • (meth)acrylic acid ester monomer is a general term for "acrylic acid ester monomer” and “methacrylic acid ester monomer” and means one or both of them.
  • methyl (meth)acrylate means one or both of “methyl acrylate” and “methyl methacrylate”.
  • the (meth)acrylic acid ester monomers may be used alone or in combination of two or more kinds.
  • the weight average molecular weight (Mw) of the styrene-acrylic resin is preferably within the range of 5,000 to 150,000, and more preferably within the range of 30,000 to 120,000, from the viewpoint of being able to control the plasticity.
  • the weight average molecular weight (Mw) can be measured in the same manner as for the (meth)acrylic resin described above.
  • the styrene-acrylic resin may be a commercially available product, for example, "TX320XL” (MS resin, manufactured by Denka Co., Ltd.).
  • the cycloolefin resin is preferably a polymer of a cycloolefin monomer, or a copolymer of a cycloolefin monomer and another monomer copolymerizable with the cycloolefin monomer.
  • the cycloolefin monomer is preferably a cycloolefin monomer having a norbornene skeleton. Among them, a cycloolefin monomer having a structure represented by the following general formula (A-1) or (A-2) is more preferable.
  • R 1 to R 4 each independently represent a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a polar group.
  • p represents an integer of 0 to 2.
  • R 1 to R 4 do not all represent hydrogen atoms at the same time, R 1 and R 2 do not both represent hydrogen atoms, and R 3 and R 4 do not both represent hydrogen atoms.
  • the hydrocarbon group having 1 to 30 carbon atoms represented by R 1 to R 4 is, for example, preferably a hydrocarbon group having 1 to 10 carbon atoms, and more preferably a hydrocarbon group having 1 to 5 carbon atoms.
  • the hydrocarbon group having 1 to 30 carbon atoms may further have a linking group containing, for example, a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, or a silicon atom.
  • linking groups include divalent polar groups such as a carbonyl group, an imino group, an ether bond, a silyl ether bond, and a thioether bond.
  • Examples of the hydrocarbon group having 1 to 30 carbon atoms include a methyl group, an ethyl group, a propyl group, and a butyl group.
  • examples of the polar group represented by R 1 to R 4 include a carboxy group, a hydroxy group, an alkoxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an amino group, an amide group, and a cyano group.
  • a carboxy group, a hydroxy group, an alkoxycarbonyl group, or an aryloxycarbonyl group is preferable. From the viewpoint of solubility during solution casting, an alkoxycarbonyl group or an aryloxycarbonyl group is preferable.
  • p is preferably 1 or 2 from the viewpoint of increasing heat resistance.
  • p is 1 or 2 from the viewpoint of increasing heat resistance.
  • the resulting polymer becomes bulky and the glass transition temperature is likely to be improved.
  • it becomes somewhat responsive to humidity, making it easier to control the curl balance when formed into a laminate.
  • R5 represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkylsilyl group having an alkyl group having 1 to 5 carbon atoms.
  • R6 represents a carboxy group, a hydroxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an amino group, an amido group, a cyano group, or a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom).
  • p represents an integer of 0 to 2.
  • R 5 in the above general formula (A-2) is preferably a hydrocarbon group having 1 to 5 carbon atoms, and more preferably a hydrocarbon group having 1 to 3 carbon atoms.
  • R 6 is preferably a carboxy group, a hydroxy group, an alkoxycarbonyl group, or an aryloxycarbonyl group, and from the viewpoint of solubility during solution casting, is more preferably an alkoxycarbonyl group or an aryloxycarbonyl group.
  • p in the above general formula (A-2) is preferably 1 or 2.
  • p is 1 or 2
  • the resulting polymer becomes bulky and the glass transition temperature is easily improved.
  • the cycloolefin monomer is preferably a cycloolefin monomer having the structure represented by the above general formula (A-2).
  • the crystallinity of an organic compound is reduced by breaking the symmetry, and the solubility in an organic solvent is improved.
  • R 5 and R 6 in general formula (A-2) are substituted on only one side of the carbon atoms constituting the ring with respect to the symmetric axis of the molecule, and therefore the symmetry of the molecule is low. That is, the cycloolefin monomer having the structure represented by general formula (A-2) is highly soluble and is therefore suitable for producing an optical film by a solution casting method.
  • the content of the cycloolefin monomer having the structure represented by general formula (A-2) in the cycloolefin resin is preferably 70 mol% or more relative to the total number of moles of all cycloolefin monomers constituting the cycloolefin resin. Also, it is more preferable that it is 80 mol% or more, and even more preferable that it is 100 mol%.
  • the content of the cycloolefin monomer having the structure represented by general formula (A-2) is 70 mol% or more, the orientation of the cycloolefin resin is increased, and the phase difference (retardation) value is likely to increase.
  • cycloolefin monomers having a structure represented by general formula (A-1) are shown as example compounds 1 to 14.
  • specific examples of cycloolefin monomers having a structure represented by general formula (A-2) are shown as example compounds 15 to 34.
  • copolymerizable monomers capable of ring-opening copolymerization include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and dicyclopentadiene.
  • Examples of copolymerizable monomers capable of addition copolymerization include unsaturated double bond-containing compounds, vinyl cyclic hydrocarbon monomers, (meth)acrylates, etc.
  • Examples of unsaturated double bond-containing compounds include olefin compounds having 2 to 12 carbon atoms (preferably 2 to 8), such as ethylene, propylene, and butene.
  • Examples of vinyl cyclic hydrocarbon monomers include vinylcyclopentene monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene.
  • (meth)acrylates examples include alkyl (meth)acrylates having 1 to 20 carbon atoms, such as methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and cyclohexyl (meth)acrylate.
  • the content of the cycloolefin monomer in a copolymer of a cycloolefin monomer and a copolymerizable monomer is preferably within the range of 20 to 80 mol %, and more preferably within the range of 30 to 70 mol %, based on the total of all monomers constituting the copolymer.
  • the cycloolefin resin is a polymer obtained by homopolymerizing or copolymerizing a cycloolefin monomer having a norbornene skeleton, preferably a cycloolefin monomer having a structure represented by the above general formula (A-1) or (A-2).
  • Examples of such polymers include the following.
  • Ring-opening polymer of cycloolefin monomer 1) Ring-opening polymer of cycloolefin monomer; 2) Ring-opening copolymer of cycloolefin monomer and a copolymerizable monomer capable of ring-opening copolymerization therewith; 3) Hydrogenated product of ring-opening (co)polymer of 1) or 2) above; 4) (co)polymer obtained by cyclizing ring-opening (co)polymer of 1) or 2) above by Friedel-Crafts reaction and then hydrogenating it; 5) Saturated copolymer of cycloolefin monomer and unsaturated double bond-containing compound; 6) Addition copolymer of cycloolefin monomer and vinyl cyclic hydrocarbon monomer and hydrogenated product thereof; 7) Alternating copolymer of cycloolefin monomer and (meth)acrylate.
  • the polymers 1) to 7) above can all be obtained by known methods, for example, the methods described in JP-A-2008-107534 and JP-A-2005-227606.
  • the catalyst and solvent used in the ring-opening copolymerization 2) above can be, for example, those described in paragraphs 0019 to 0024 of JP-A-2008-107534.
  • the catalyst used in the hydrogenation 3) and 6) above can be, for example, those described in paragraphs 0025 to 0028 of JP-A-2008-107534.
  • the acidic compound used in the Friedel-Crafts reaction 4) above can be, for example, those described in paragraph 0029 of JP-A-2008-107534.
  • the catalyst used in the addition polymerization 5) to 7) above can be, for example, those described in paragraphs 0058 to 0063 of JP-A-2005-227606.
  • the alternating copolymerization reaction of 7) above can be carried out, for example, by the method described in paragraphs 0071 to 0072 of JP 2005-227606 A.
  • the cycloolefin resin preferably contains at least one of a structural unit represented by the following general formula (B-1) and a structural unit represented by the following general formula (B-2). It is more preferred that the cycloolefin resin contains only a structural unit represented by general formula (B-2), or contains both a structural unit represented by general formula (B-1) and a structural unit represented by general formula (B-2).
  • the structural unit represented by general formula (B-1) is a structural unit derived from the cycloolefin monomer represented by the aforementioned general formula (A-1), and the structural unit represented by general formula (B-2) is a structural unit derived from the cycloolefin monomer represented by the aforementioned general formula (A-2).
  • R 1 to R 4 and p have the same meanings as R 1 to R 4 and p in the above general formula (A-1), respectively.
  • R 5 to R 6 and p have the same meanings as R 5 to R 6 and p in general formula (A-2), respectively.
  • the cycloolefin resin used in the present invention may be a commercially available product.
  • examples of commercially available cycloolefin resins include ARTON (registered trademark, the same applies below) G (e.g., G7810, etc.), ARTON F, ARTON R (e.g., R4500, R4900, R5000, etc.), and ARTON RX (e.g., RX4500, etc.), all manufactured by JSR Corporation.
  • the intrinsic viscosity [ ⁇ ]inh of the cycloolefin resin at 30° C. is preferably within the range of 0.2 to 5 cm 3 /g, more preferably within the range of 0.3 to 3 cm 3 /g, and even more preferably within the range of 0.4 to 1.5 cm 3 /g.
  • the number average molecular weight (Mn) of the cycloolefin resin is preferably within the range of 8,000 to 100,000, more preferably within the range of 10,000 to 80,000, and further preferably within the range of 12,000 to 50,000.
  • the weight average molecular weight (Mw) of the cycloolefin resin is preferably within a range of 20,000 to 300,000, more preferably within a range of 30,000 to 250,000, and further preferably within a range of 40,000 to 200,000.
  • the weight average molecular weight (Mw) can be measured by the same method as that for the (meth)acrylic resin described above.
  • the cycloolefin resin has good heat resistance, water resistance, chemical resistance, mechanical properties, and moldability as an optical film.
  • the glass transition temperature (Tg) of cycloolefin resins is usually 110°C or higher, preferably in the range of 110 to 350°C, more preferably in the range of 120 to 250°C, and even more preferably in the range of 120 to 220°C. Having a Tg of 110°C or higher makes it possible to suppress deformation under high temperature conditions. On the other hand, having a Tg of 350°C or lower makes molding easier and suppresses deterioration of the resin due to heat during molding processing.
  • the content of the cycloolefin resin is preferably 70% by mass or more, and more preferably 80% by mass or more, based on the total mass of the optical film.
  • Polyimide is synthesized by a polymerization reaction between a tetracarboxylic dianhydride and a diamine.
  • tetracarboxylic dianhydride examples include aromatic tetracarboxylic dianhydrides, aliphatic tetracarboxylic dianhydrides, and alicyclic tetracarboxylic dianhydrides. Among these, aromatic tetracarboxylic dianhydrides are preferred.
  • the diamine may be an aromatic diamine, an aliphatic diamine, or an alicyclic diamine, and among these, an aromatic diamine is preferred.
  • the weight average molecular weight (Mw) of the polyimide is preferably within the range of 100,000 to 300,000, and more preferably within the range of 130,000 to 250,000. By being within the above range, it is possible to prevent the optical film from breaking due to the transport tension during transport.
  • the weight average molecular weight (Mw) can be measured in the same manner as for the (meth)acrylic resin described above.
  • the polyimide content is preferably 60% by mass or more, and more preferably 70% by mass or more, based on the total mass of the optical film.
  • Cellulose ester is a polymer in which ⁇ -glucose units are linked in a linear chain via ⁇ -1,4-glycosidic bonds.
  • Cellulose ester is cellulose in which some or all of the hydrogen atoms in the hydroxyl groups (-OH) at the 2-, 3-, and 6-positions in one glucose unit are substituted with acyl groups.
  • the cellulose ester is not particularly limited, but is preferably an ester of a linear or branched carboxylic acid having about 2 to 22 carbon atoms.
  • the carboxylic acid constituting the ester include an aliphatic carboxylic acid, an alicyclic carboxylic acid, and an aromatic carboxylic acid.
  • Examples of the substituted acyl groups of cellulose esters include acyl groups having 2 to 22 carbon atoms, such as acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl, hexanoyl, octanoyl, lauroyl, and stearoyl.
  • the carboxylic acid (acyl group) constituting the ester may have a substituent.
  • the carboxylic acid constituting the ester is preferably a lower fatty acid having 6 or less carbon atoms, more preferably a lower fatty acid having 3 or less carbon atoms.
  • the acyl group in the cellulose ester may be of a single type or a combination of multiple acyl groups.
  • cellulose esters include cellulose acetates such as diacetyl cellulose (DAC) and triacetyl cellulose (TAC), as well as mixed fatty acid esters of cellulose to which a propionate group or a butyrate group is bonded in addition to an acetyl group, such as cellulose acetate propionate (CAP), cellulose acetate butyrate, and cellulose acetate propionate butyrate.
  • CAP cellulose acetate propionate
  • CAP cellulose acetate propionate
  • CAP cellulose acetate propionate
  • CAP cellulose acetate propionate
  • CAP cellulose acetate propionate
  • CAP cellulose acetate propionate
  • CAP cellulose acetate propionate
  • CAP cellulose acetate propionate
  • CAP cellulose acetate butyrate
  • cellulose acetate propionate butyrate cellulose acetate propionate butyrate
  • the degree of acyl substitution represents the average number of acyl groups per glucose unit, i.e., how many of the hydrogen atoms of the hydroxyl groups at the 2-, 3-, and 6-positions in one glucose unit are substituted with acyl groups. Therefore, the maximum degree of substitution of the acyl group is 3.0, which means that all of the hydrogen atoms of the hydroxy groups at the 2-, 3- and 6-positions are substituted with acyl groups.
  • the acyl groups may be substituted evenly at the 2-, 3- and 6-positions of one glucose unit, or may be substituted with a distribution.
  • the degree of acyl substitution can be determined by the method specified in ASTM-D817-96.
  • the substitution degree of the acyl group of the cellulose ester is too large, the retardation is difficult to be expressed, so that it is necessary to increase the stretching ratio when producing the optical film. However, it is difficult to uniformly stretch at a high stretching ratio, and the thickness of the optical film tends to vary greatly.
  • the smaller the substitution degree of the acyl group of the cellulose ester the easier it is to express the retardation, so that the thickness of the optical film can be made thin and uniform.
  • the degree of substitution of the acyl group in the cellulose ester is too small, the durability of the optical film decreases, and therefore, from the viewpoint of durability, it is preferable not to make the degree of substitution too small.
  • the humidity-dependent change in retardation (Rt, phase difference) in the thickness direction occurs when water molecules coordinate with the carbonyl groups of cellulose. Therefore, the smaller the degree of acyl group substitution, i.e., the fewer the carbonyl groups in the cellulose, the less humidity-dependent change in Rt occurs.
  • the degree of substitution of the acyl group in the cellulose ester is preferably within a range of 2.1 to 2.5, and more preferably within a range of 2.2 to 2.45.
  • environmental fluctuations particularly fluctuations in Rt due to humidity
  • the uniformity of the thickness of the optical film can be improved.
  • the flowability and stretchability during production of the optical film can be improved.
  • the degree of substitution of the acyl group of the cellulose ester satisfies both of the following formulas (a) and (b).
  • X is the degree of substitution of the acetyl group
  • Y is the degree of substitution of the propionyl group or the butyryl group, or the degree of substitution of a mixture thereof.
  • the degree of substitution X of the acetyl group of cellulose acetate preferably satisfies 2.1 ⁇ X ⁇ 2.5, and more preferably satisfies 2.15 ⁇ X ⁇ 2.45.
  • An example of cellulose acetate that satisfies the above range is cellulose diacetate (DAC).
  • the cellulose ester is preferably cellulose acetate propionate (CAP).
  • CAP cellulose acetate propionate
  • X and Y satisfy any of the following: 0.95 ⁇ X ⁇ 2.25, 0.1 ⁇ Y ⁇ 1.2, 2.15 ⁇ X+Y ⁇ 2.45.
  • cellulose acetates with different degrees of substitution may be mixed. There are no particular limitations on the mixing ratio of the different cellulose acetates.
  • the number average molecular weight (Mn) of the cellulose ester is preferably within the range of 2 ⁇ 10 4 to 3 ⁇ 10 5 , more preferably within the range of 2 ⁇ 10 4 to 1.2 ⁇ 10 5 , and even more preferably within the range of 4 ⁇ 10 4 to 8 ⁇ 10 4 .
  • the number average molecular weight (Mn) of cellulose ester can be measured in the same manner as for the (meth)acrylic resin described above.
  • the weight average molecular weight (Mw) of the cellulose ester is preferably within the range of 2 ⁇ 10 4 to 1 ⁇ 10 6 , more preferably within the range of 2 ⁇ 10 4 to 1.2 ⁇ 10 5 , and even more preferably within the range of 4 ⁇ 10 4 to 8 ⁇ 10 4 .
  • the raw cellulose for cellulose ester is not particularly limited, but examples include cotton linters, wood pulp, kenaf, etc. Furthermore, the cellulose esters obtained from these may be mixed in any desired ratio.
  • Cellulose esters such as cellulose acetate and cellulose acetate propionate can be synthesized by known methods.
  • the raw material cellulose, organic acid (acetic acid, propionic acid, etc.), acid anhydride (acetic anhydride, propionic anhydride, etc.) and catalyst (sulfuric acid, etc.) are mixed together to esterify the cellulose, and the reaction is allowed to proceed until a cellulose triester is produced.
  • mixed ester type cellulose esters such as cellulose acetate propionate and cellulose acetate butyrate.
  • the cellulose triester is then hydrolyzed to give a cellulose ester having the desired degree of acyl substitution. Thereafter, the cellulose ester is finally obtained through steps such as filtration, precipitation, washing, dehydration, drying, etc. Specifically, the cellulose ester can be synthesized by referring to the method described in JP-A-10-45804.
  • rubber particles refers to particles containing a resin that exhibits rubber elasticity at room temperature.
  • the optical film according to the present invention preferably contains rubber particles.
  • toughness flexibleibility
  • loss tangent loss tangent
  • the optical film B contains rubber particles.
  • the loss tangent (tan ⁇ B ) of the optical film B can be appropriately adjusted, and the impact resistance can be further improved.
  • the layer structure of the rubber particles according to the present invention may be a single layer structure or a multi-layer structure.
  • the resin exhibiting rubber elasticity at room temperature (hereinafter also referred to as "rubber-like polymer”) is not particularly limited.
  • the order of monomer arrangement is also not particularly limited, and may be, for example, linear, comb-like (graft type), or branched (star type).
  • the rubber-like polymer may have a structure that is partially crosslinked with a crosslinkable monomer.
  • the rubber-like polymer is preferably a soft crosslinked polymer having a glass transition temperature (Tg) of 0° C. or lower, from the viewpoint of exhibiting rubber elasticity at room temperature.
  • crosslinked polymers include butadiene-based crosslinked polymers, (meth)acrylic crosslinked polymers, organosiloxane crosslinked polymers, etc.
  • (meth)acrylic crosslinked polymers are preferred, and acrylic crosslinked polymers are more preferred, from the viewpoint of a small difference in refractive index from thermoplastic (meth)acrylic resins and less loss of transparency of the optical film.
  • the rubber particles according to the present invention are preferably particles containing an acrylic crosslinked polymer (hereinafter also referred to as an "acrylic rubber-like polymer").
  • the content of rubber particles is preferably within the range of 10 to 80% by mass relative to the total mass of the optical film.
  • the optical film has an appropriate hardness and can obtain the desired storage modulus and loss tangent (tan ⁇ ).
  • optical film B according to the present invention contains at least a combination of a (meth)acrylic resin and rubber particles of a graft copolymer.
  • the content of the (meth)acrylic resin is preferably within the range of 5 to 95% by mass relative to the total mass of the optical film. It is more preferably within the range of 10 to 60% by mass, even more preferably within the range of 10 to 50% by mass, and particularly preferably within the range of 10 to 40% by mass.
  • the content of the rubber particles is preferably within the range of 10 to 80% by mass, based on the total mass of the optical film. Also, it is more preferable that it is within the range of 20 to 60% by mass, and even more preferable that it is within the range of 20 to 50% by mass. By being within the above range, the size of the aggregates becomes sufficient and uniform, foreign matter is less likely to be mixed into the film, and an optical film with improved optical properties and mechanical properties can be obtained.
  • the rubber particles according to the present invention preferably contain an acrylic rubber-like polymer.
  • the acrylic rubber-like polymer will be referred to as "acrylic rubber-like polymer (a)" below.
  • the acrylic rubber-like polymer (a) is a crosslinked polymer having, as a main component, a structural unit derived from an acrylic ester.
  • "having as a main component” means that the content of structural units derived from acrylic ester is within the range described below.
  • the acrylic rubber-like polymer (a) is preferably a crosslinked polymer having structural units derived from an acrylic acid ester, structural units derived from other monomers copolymerizable therewith, and structural units derived from a polyfunctional monomer having two or more radically polymerizable groups (non-conjugated reactive double bonds) in one molecule.
  • the acrylic acid ester is preferably an alkyl acrylate having an alkyl group having 1 to 12 carbon atoms, such as methyl acrylate (methyl acrylate), ethyl acrylate (ethyl acrylate), n-propyl acrylate (n-propyl acrylate), n-butyl acrylate (n-butyl acrylate), sec-butyl acrylate (sec-butyl acrylate), isobutyl acrylate (isobutyl acrylate), benzyl acrylate (benzyl acrylate), cyclohexyl acrylate (cyclohexyl acrylate), 2-ethylhexyl acrylate (2-ethylhexyl acrylate), or n-octyl acrylate (n-octyl acrylate). These may be used alone or in combination of two or more.
  • the content of structural units derived from acrylic esters is preferably within the range of 40 to 90 mass % of all structural units constituting the acrylic rubber-like polymer (a), and more preferably within the range of 50 to 80 mass %. By being within the above range, sufficient toughness can be imparted to the optical film.
  • Examples of other monomers copolymerizable with acrylic acid esters include methacrylic acid esters such as methyl methacrylate, styrenes such as styrene and methylstyrene, (meth)acrylonitriles, (meth)acrylamides, and (meth)acrylic acid.
  • methacrylic acid esters such as methyl methacrylate
  • styrenes such as styrene and methylstyrene
  • (meth)acrylonitriles such as methyl)acrylamides
  • (meth)acrylic acid examples include methacrylic acid esters such as methyl methacrylate, styrenes such as styrene and methylstyrene, (meth)acrylonitriles, (meth)acrylamides, and (meth)acrylic acid.
  • styrenes are preferred. These may be used alone or in combination of two or more.
  • the content of structural units derived from other monomers copolymerizable with acrylic esters is preferably within the range of 5 to 55% by mass, and more preferably within the range of 10 to 45% by mass, based on the total structural units constituting the acrylic rubber-like polymer (a).
  • polyfunctional monomers having two or more radically polymerizable groups in one molecule include allyl (meth)acrylate, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl malate, divinyl adipate, divinyl benzene, ethylene glycol di(meth)acrylate, diethylene glycol (meth)acrylate, triethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, dipropylene glycol di(meth)acrylate, and polyethylene glycol di(meth)acrylate.
  • the content of structural units derived from polyfunctional monomers having two or more radically polymerizable groups in one molecule is preferably within the range of 0.05 to 10 mass % of all structural units constituting the acrylic rubber-like polymer (a), and more preferably within the range of 0.1 to 5 mass %.
  • a content of 0.05 mass % or more it is easy to increase the degree of crosslinking of the obtained acrylic rubber-like polymer (a), and the hardness and rigidity of the optical film are less likely to be impaired.
  • the toughness of the optical film is less likely to be impaired.
  • composition of the monomers constituting the acrylic rubber-like polymer (a) can be measured, for example, by the peak area ratio detected by pyrolysis GC-MS.
  • the glass transition temperature (Tg) of the acrylic rubber-like polymer (a) is preferably 0°C or lower, and more preferably -10°C or lower. A glass transition temperature of 0°C or lower can impart appropriate toughness to the optical film.
  • the glass transition temperature (Tg) of the acrylic rubber-like polymer (a) can be measured by the same method as described above.
  • the glass transition temperature (Tg) of the acrylic rubber-like polymer (a) can be adjusted by the composition of the acrylic rubber-like polymer (a). For example, in order to lower the glass transition temperature (Tg), it is preferable to adjust the mass ratio of the acrylic ester having an alkyl group with 4 or more carbon atoms to the other monomer copolymerizable with the acrylic ester.
  • the mass ratio is expressed as the mass of the acrylic ester/the mass of the other monomer copolymerizable with the acrylic ester.
  • the mass ratio is preferably 3 or more, and is preferably within the range of 4 to 10.
  • the particles containing the acrylic rubber-like polymer (a) may be particles consisting of only the acrylic rubber-like polymer (a). They may also be particles having a hard layer consisting of a hard crosslinked polymer (c) having a glass transition temperature (Tg) of 20°C or higher, and a soft layer consisting of the acrylic rubber-like polymer (a) arranged around it. In addition, they may be particles consisting of an acrylic graft copolymer obtained by polymerizing a mixture of monomers such as methacrylic acid esters in at least one stage in the presence of the acrylic rubber-like polymer (a). The particles consisting of the acrylic graft copolymer may be core-shell type particles having a core containing the acrylic rubber-like polymer (a) and a shell covering the core.
  • the core contains an acrylic rubber-like polymer (a) and may further contain a hard crosslinked polymer (c) as necessary. That is, the core may have a soft layer made of the acrylic rubber-like polymer (a) and a hard layer made of the hard crosslinked polymer (c) disposed inside the soft layer.
  • the rigid crosslinked polymer will be referred to as "crosslinked polymer (c)" hereinafter.
  • the crosslinked polymer (c) is a crosslinked polymer containing a methacrylic acid ester as a main component.
  • the crosslinked polymer (c) is preferably a crosslinked polymer having a structural unit derived from a methacrylic acid ester, a structural unit derived from another monomer copolymerizable therewith, and a structural unit derived from a polyfunctional monomer having two or more radically polymerizable groups in one molecule.
  • the methacrylic acid ester is preferably an alkyl methacrylate ester, such as the above-mentioned alkyl acrylate ester in which the alkyl acid is replaced with methacrylic acid.
  • alkyl methacrylate ester examples include the same monomers as those described above as the other monomers copolymerizable with the acrylic acid ester.
  • polyfunctional monomer having two or more radically polymerizable groups in one molecule include the same as those mentioned above.
  • the content of structural units derived from methacrylic acid alkyl esters is preferably within the range of 40 to 100% by mass relative to all structural units constituting the crosslinked polymer (c).
  • the content of structural units derived from other monomers copolymerizable with methacrylic acid esters is preferably within the range of 60 to 0% by mass relative to all structural units constituting the crosslinked polymer (c).
  • the content of structural units derived from polyfunctional monomers having two or more radically polymerizable groups in one molecule is preferably within the range of 0.01 to 10% by mass relative to all structural units constituting the crosslinked polymer (c).
  • the shell portion preferably contains a methacrylic polymer (b) (another polymer) having as its main component a structural unit derived from a methacrylic acid ester, graft-bonded to the acrylic rubber-like polymer (a).
  • a methacrylic polymer having a structural unit derived from a methacrylic acid ester as a main component will be referred to as a "methacrylic polymer (b)" hereinafter.
  • “having as a main component” means that the content of the structural unit derived from the methacrylic acid ester is within the range described below.
  • the methacrylic acid ester constituting the methacrylic polymer (b) is preferably a methacrylic acid alkyl ester having an alkyl group of 1 to 12 carbon atoms, such as methyl methacrylate. These may be used alone or in combination of two or more.
  • the content of the methacrylic acid ester is preferably 50% by mass or more relative to all structural units constituting the methacrylic polymer (b).
  • the content of the methacrylic acid ester is more preferably 70% by mass or more relative to all structural units constituting the methacrylic polymer (b).
  • the methacrylic polymer (b) may further have a structural unit derived from another monomer copolymerizable with the methacrylic acid ester.
  • the other copolymerizable monomer include acrylic acid esters such as methyl acrylate (methyl acrylate), ethyl acrylate (ethyl acrylate), and n-butyl acrylate (n-butyl acrylate); and (meth)acrylic monomers having an alicyclic, heterocyclic or aromatic ring (ring-containing (meth)acrylic monomers) such as benzyl (meth)acrylate (benzyl (meth)acrylate), dicyclopentanyl (meth)acrylate (dicyclopentanyl (meth)acrylate), and phenoxyethyl (meth)acrylate (phenoxyethyl (meth)acrylate).
  • the content of structural units derived from other copolymerizable monomers is preferably 50% by mass or less, and more preferably 30% by mass or less, based on the total structural units constituting the methacrylic polymer (b).
  • the ratio of the graft component in the rubber particles is preferably in the range of 10 to 250% by mass, and more preferably in the range of 15 to 150% by mass.
  • a graft ratio of 10% by mass or more means that the ratio of the graft component, i.e., the methacrylic polymer (b) whose main component is a structural unit derived from a methacrylic acid ester, is appropriately high. This makes it easier to increase the compatibility between the rubber particles and the methacrylic resin, making the rubber particles even less likely to aggregate. In addition, the rigidity of the optical film is less likely to be impaired.
  • the ratio of the acrylic rubber-like polymer (a) is not too low, so that the toughness of the optical film is less likely to be impaired.
  • the brittleness of the optical film can be sufficiently improved.
  • the graft rate can be measured using the following method.
  • the shape of the rubber particles is not particularly limited, but it is preferable that the rubber particles have a shape close to a perfect sphere.
  • the term "nearly spherical” refers to a shape in which the aspect ratio of the rubber particles is within the range of 1 to 2 when the cross section or surface of the optical film is observed.
  • the laminate is sufficiently resistant to deformation caused by contact with the rolls during transportation and deformation caused by internal stress during winding.
  • the average particle size of the rubber particles is preferably within the range of 100 to 400 nm. Having a particle size of 100 nm or more provides the optical film with sufficient toughness and stress relaxation properties. Furthermore, having a particle size of 400 nm or less ensures that the transparency of the optical film is not easily impaired. From the above viewpoints, it is more preferable that the average particle size of the rubber particles is within the range of 150 to 300 nm.
  • the average particle size of rubber particles can be calculated using the following method.
  • the average particle size of rubber particles can be measured as the average of the circle-equivalent diameters of 100 particles obtained by photographing the surface or slices of the laminate with a scanning electron microscope (SEM) or a transmission electron microscope (TEM).
  • the circle-equivalent diameter can be calculated by converting the projected area of the particle obtained by photographing into the diameter of a circle with the same area. In this case, rubber particles observed by SEM or TEM observation at a magnification of 5000 times are used to calculate the average particle size.
  • the optical film according to the present invention can adjust the light transmittance by containing a colorant.
  • the colorant may be used alone or in combination of two or more kinds. From the viewpoint of the balance between brightness and color gamut, the content of the colorant is preferably within the range of 0.05 to 1.02% by mass based on the total mass of the resin for optical films.
  • At least one of them has a maximum absorption wavelength in the wavelength region of 570 to 610 nm. This makes it possible to reduce the average light transmittance of the optical film in the wavelength region of 570 to 610 nm, and to prevent the color gamut of the display device from narrowing.
  • the absorption maximum wavelength in the wavelength region of 570 to 610 nm is the maximum absorption maximum wavelength of the colorant.
  • maximum absorption maximum wavelength refers to the absorption maximum wavelength when there is only one absorption maximum wavelength, and to the absorption maximum wavelength that shows the maximum absorbance when there are multiple absorption maximum wavelengths.
  • the content of the colorant having a maximum absorption wavelength in the wavelength region of 570 to 610 nm is preferably within the range of 0.02 to 0.6 mass %, and more preferably within the range of 0.05 to 0.3 mass %, relative to the total mass of the resin for optical films.
  • the absorption maximum wavelength in the wavelength region of 420 to 460 nm is the longest absorption maximum wavelength of the colorant.
  • the content of the colorant having a maximum absorption wavelength in the wavelength region of 420 to 460 nm is preferably within the range of 0.005 to 0.3 mass %, and more preferably within the range of 0.01 to 0.3 mass %, relative to the total mass of the resin for optical films.
  • the above absorption maximum wavelength can be determined by dispersing the colorant in dichloromethane and measuring the absorption spectrum using an ultraviolet-visible spectrophotometer (e.g., "UV-2450" (manufactured by Shimadzu Corporation)).
  • an ultraviolet-visible spectrophotometer e.g., "UV-2450” (manufactured by Shimadzu Corporation)
  • the coloring agent may be a commercially available product or a synthetic product.
  • commercially available products include, but are not limited to, "#950” (manufactured by Mitsubishi Chemical Corporation), “FDR series”, “FDG series”, and “FDB series” (all manufactured by Yamada Chemical Industry Co., Ltd.), “Kayaset Black A-N” (manufactured by Nippon Kayaku Co., Ltd.), “NUBIAN (registered trademark) BLACK PC-5857” (manufactured by Orient Chemical Industry Co., Ltd.), and “Plast Black 8950-N” (manufactured by Arimoto Chemical Industry Co., Ltd.).
  • the coloring agent is not particularly limited, but examples include dyes and pigments.
  • the dyes are not particularly limited, and examples thereof include the following. However, from the viewpoint of absorbing light of a wide wavelength range, it is preferable to use at least two or more of the following dyes in combination. Also, a commercially available product in which two or more dyes are mixed in combination may be used.
  • Magenta dyes include “MS Magenta VP”, “MS Magenta HM-1450", “MS Magenta HSo-147” (all manufactured by Mitsui Toatsu Co., Ltd.), “AIZENSOT Red-1”, “AIZENSOT Red-2”, “AIZENSOT Red-3”, “AIZENSOT Pink-1”, “SPIRON Red GEH SPECIAL” (all manufactured by Hodogaya Chemical Co., Ltd.), “RESOLIN Red FB 200%”, “MACROLEX (registered trademark) Re d Violet R, MACROLEX (registered trademark) ROT5B (all manufactured by Bayer Japan), KAYASET Red B, KAYASET Red 130, KAYASET Red 802 (all manufactured by Nippon Kayaku), PHLOXIN, ROSE BENGAL, ACID Red (all manufactured by Daiwa Kasei), HSR-31, DIARESIN (registered trademark) Red K (all manufactured by Mitsubishi Kasei), and Oil Red (manufactured
  • Cyan dyes include "MS Cyan HM-1238", “MS Cyan HSo-16", “Cyan HSo-144", and “MS Cyan VPG” (all manufactured by Mitsui Toatsu Co., Ltd.), “AIZENSOT Blue-4" (manufactured by Hodogaya Chemical Co., Ltd.), “RESOLIN BR.Blue BGLN 200%, “MACROLEX (registered trademark) Blue RR”, “CERES (registered trademark) Blue GN”, “SIRIUS (registered trademark) SUPRATURQ.Blue Z-BGL”, and “SIRIUS (registered trademark) SUPRATURQ.Blue FB-LL 330%” (all manufactured by Bayer Japan Ltd.).
  • Examples include “KAYASET Blue FR”, “KAYASET Blue N”, “KAYASET Blue 814”, “Turq. Blue GL-5200", “Light Blue BGL-5200” (all manufactured by Nippon Kayaku Co., Ltd.), “DAIWA Blue 7000", “Oleosol (registered trademark) Fast Blue GL” (all manufactured by Daiwa Kasei Co., Ltd.), “DIARESIN (registered trademark) Blue P” (manufactured by Mitsubishi Kasei Corporation), “SUDAN Blue 670", “NEOPEN Blue 808", and “ZAPON Blue 806” (all manufactured by BASF Japan Ltd.).
  • Yellow dyes include "MS Yellow HSm-41", “Yellow KX-7", and “Yellow EX-27” (all manufactured by Mitsui Toatsu Co., Ltd.), “AIZENSOT Yellow-1", “AIZENSOT Yellow W-3", and “AIZENSOT Yellow-6” (all manufactured by Hodogaya Chemical Co., Ltd.), “MACROLEX (registered trademark) Yellow 6G”, and “MACROLEX (registered trademark) FLUOR.Yellow 10GN” (all manufactured by Bayer).
  • pigments are not particularly limited, and examples thereof include organic pigments, inorganic pigments, minerals, etc., having the following numbers as described in the Color Index. However, from the viewpoint of absorbing light of a wide wavelength range, it is preferable to use at least two or more of the following pigments in combination. Also, a commercially available product in which two or more of the following pigments are mixed in combination may be used.
  • Black pigments are not particularly limited, and examples thereof include carbon black, magnetic materials, iron-titanium composite oxide black, etc.
  • Carbon black is not particularly limited, and examples thereof include channel black, furnace black, acetylene black, thermal black, lamp black, etc.
  • Magnetic materials are not particularly limited, and examples thereof include ferrite, magnetite, etc.
  • the red or magenta pigment is not particularly limited, and examples thereof include C.I. Pigment Red 3, 5, 19, 22, 31, 38, 43, 48:1, 48:2, 48:3, 48:4, 48:5, 49:1, 53:1, 57:1, 57:2, 58:4, 63:1, 81, 81:1, 81:2, 81:3, 81:4, 88, 104, 108, 112, 122, 123, 144, 146, 149, 166, 168, 1 69, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257, Pigment Violet 3, 19, 23, 29, 30, 37, 50, 88, Pigment Orange 13, 16, 20, 36, Ruby (chromium-containing corundum), Garnet, Spinel, etc.
  • the blue or cyan pigment is not particularly limited, and examples thereof include C.I. Pigment Blue 1, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17-1, 22, 27, 28, 29, 36, 60, and Blue Sapphire (iron- and titanium-containing corundum).
  • the green pigment is not particularly limited, and examples thereof include C.I. Pigment Green 7, 26, 36, 50, and the like.
  • the yellow pigment is not particularly limited, and examples thereof include C.I. Pigment Yellow 1, 3, 12, 13, 14, 17, 34, 35, 37, 55, 74, 81, 83, 93, 94, 95, 97, 108, 109, 110, 137, 138, 139, 153, 154, 155, 157, 166, 167, 168, 180, 185, 193, and yellow sapphire (nickel-containing corundum).
  • the average secondary particle diameter of the pigment is not particularly limited, but is preferably 0.1 ⁇ m or more, and more preferably 0.2 ⁇ m or more. By keeping it within the above range, the sliding properties of the pigment particles are improved and they are less likely to aggregate, which further reduces unevenness in the light transmittance within the optical film.
  • the average secondary particle diameter of the pigment is not particularly limited, but is preferably 3 ⁇ m or less, and more preferably 2.6 ⁇ m or less. By keeping it within the above range, dispersion spots in the optical film are less likely to occur, unevenness in the light transmittance in the optical film is further reduced, and the haze value is also reduced.
  • the average secondary particle diameter of a pigment can be determined by directly measuring the size of the secondary particles from an electron microscope photograph of an optical film. Specifically, a transmission electron microscope (TEM) "H-7650" (Hitachi High-Tech Corporation) is used to measure particle images, and the average equivalent diameter of a circle with an equal area of 100 randomly selected secondary particles is calculated, and this value is taken as the average secondary particle diameter.
  • TEM transmission electron microscope
  • the optical film further contains fine particles.
  • inorganic compound particles examples include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, and calcium phosphate.
  • Examples of fine particles of organic compounds include polytetrafluoroethylene, cellulose acetate, polystyrene, polymethyl methacrylate, polypropyl methacrylate, polymethyl acrylate, polyethylene carbonate, acrylic styrene resins, silicone resins, polycarbonate, benzoguanamine resins, melamine resins, polyolefin powders, polyester, polyamide, polyimide, polyethylene fluoride resins, etc.
  • Other examples include crushed fractions of organic polymer compounds such as starch, and polymer compounds synthesized by suspension polymerization.
  • the fine particles preferably contain silicon, and more preferably silicon dioxide, from the viewpoint of reducing turbidity.
  • Commercially available products of such fine particles include, for example, Aerosil (registered trademark, the same applies below) R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, and TT600 (all manufactured by Nippon Aerosil Co., Ltd.).
  • the content of the fine particles is preferably within the range of 0.05 to 10% by mass relative to the total mass of the optical film.
  • the method for producing the optical film is not particularly limited, but from the viewpoint of obtaining a desired optical film, it is preferable to produce the optical film by a solution casting method.
  • the optical film A and the optical film B may or may not be produced by the same method.
  • a dope containing a resin, a solvent, and any other ingredients is prepared, and then the dope is applied to a substrate and then dried to obtain an optical film.
  • the solvent used for the dope is not particularly limited as long as it can disperse the resin and, if necessary, rubber particles, colorant, etc. well.
  • the solvent include alcohols such as methanol, ethanol, propanol, n-butanol, 2-butanol, tert-butanol, cyclohexanol, etc.; ketones such as methyl ethyl ketone (MEK), methyl isobutyl ketone, acetone, etc.; esters such as ethyl acetate, methyl acetate, ethyl lactate, isopropyl acetate, amyl acetate, ethyl butyrate, etc.; ethers such as tetrahydrofuran (THF), 1,4-dioxane, etc.; glycol ethers; and hydrocarbons such as toluene, benzene,
  • glycol ethers examples include propylene glycol mono (C1-C4) alkyl ethers and propylene glycol mono (C1-C4) alkyl ether esters.
  • propylene glycol mono(C1-C4) alkyl ethers include propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, and propylene glycol monobutyl ether.
  • propylene glycol mono (C1-C4) alkyl ether esters include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and the like. These may be used alone or in combination of two or more.
  • methyl ethyl ketone, ethyl acetate, acetone, or tetrahydrofuran is preferred from the viewpoints of ease of dissolving the resin material, low boiling point, and ease of increasing the drying speed and productivity.
  • solvents may be further mixed with a solvent such as dichloromethane.
  • the solids concentration of the dope is preferably within the range of, for example, 5 to 20% by mass in order to make it easier to adjust the viscosity.
  • the dope may further contain other components in addition to those described above, if necessary.
  • the other components include a matting agent (fine particles), an ultraviolet absorbing agent, a surfactant, and the like.
  • matting agent can impart slipperiness to the optical film.
  • matting agents include inorganic fine particles such as silica particles, and organic fine particles with a glass transition temperature of 80°C or higher.
  • ultraviolet absorbers examples include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, and triazine-based ultraviolet absorbers.
  • Surfactants include, for example, anionic surfactants such as carboxylic acid type, sulfonic acid type, sulfate ester type, and phosphate ester type; cationic surfactants such as alkylamine salt type and quaternary ammonium salt type; and amphoteric surfactants such as carboxybetaine type, 2-alkylimidazoline derivative type, glycine type, and amine oxide type. Any type can be used.
  • anionic surfactants such as carboxylic acid type, sulfonic acid type, sulfate ester type, and phosphate ester type
  • cationic surfactants such as alkylamine salt type and quaternary ammonium salt type
  • amphoteric surfactants such as carboxybetaine type, 2-alkylimidazoline derivative type, glycine type, and amine oxide type. Any type can be used.
  • the order in which the components contained in the dope are mixed is not particularly limited.
  • the method for mixing the components is also not particularly limited, and they may be mixed using, for example, a stirrer.
  • the mixing time is not particularly limited, but is preferably within the range of 1 to 10 hours.
  • the mixing temperature is also not particularly limited, but is preferably within the range of 20 to 50°C.
  • the viscosity of the dope at 25°C is not particularly limited as long as it is sufficient to produce an optical film of the desired thickness, but it is preferably within the range of 5 to 5000 mPa ⁇ s.
  • the viscosity of the dope is 5 mPa ⁇ s or more, it is easy to produce an optical film of the desired thickness.
  • the viscosity is 5000 mPa ⁇ s or less, it is possible to suppress unevenness in thickness caused by an increase in the viscosity of the solution. From the same viewpoint, it is more preferable that the viscosity of the dope is within the range of 100 to 1000 mPa ⁇ s.
  • the viscosity of the dope at 25°C can be measured with an E-type viscometer.
  • the obtained dope may be filtered if necessary.
  • the optical film according to the present invention can be produced by applying the obtained dope to the surface of a substrate, and then drying the dope to remove the solvent from the dope. At this time, a laminated film including the substrate and the optical film is produced.
  • the step of applying the dope to the substrate and the step of forming the optical film (drying step) will be described below.
  • Step of applying dope the dope obtained above is applied to the surface of the substrate. Specifically, the dope is coated on the surface of the substrate.
  • the substrate is not particularly limited as long as it can support the optical film, but it is usually preferable for it to be a resin film.
  • polyester resin films e.g., polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), etc.
  • cycloolefin resin films COP
  • acrylic films e.g., acrylic films
  • cellulose resin films e.g., cellulose triacetate film (TAC)
  • TAC cellulose triacetate film
  • a PET film, a cellulose triacetate film (TAC) or a cycloolefin resin film is preferred.
  • the resin film for the substrate may be one that has been heat-relaxed or stretched.
  • the heat-relaxing temperature is not particularly limited, but is preferably within the range of (Tg+60) to (Tg+180)°C, where Tg is the glass transition temperature of the resin that constitutes the substrate resin film. Heat-relaxing may be performed before or after the release layer is produced.
  • the stretching treatment can increase the orientation of the resin molecules by stretching the substrate resin film, and can increase the tensile modulus of the substrate resin film.
  • the stretching treatment may be performed, for example, in the uniaxial direction of the substrate resin film or in the biaxial direction.
  • the stretching treatment may be performed under any conditions, and is preferably performed, for example, in a range of a stretch ratio of 120 to 900%.
  • the stretch ratio here is a value obtained by multiplying the stretch ratios in each direction. Whether or not the substrate resin film is stretched (whether or not it is a stretched film) can be confirmed, for example, by whether or not it has an in-plane slow axis (an axis extending in the direction in which the refractive index is maximum).
  • the substrate resin film preferably further has a release layer on its surface.
  • the presence of the release layer makes it easier to peel the optical film from the substrate resin film.
  • the release layer is not particularly limited as long as it contains a known release agent or a release agent.
  • the release agent contained in the release layer may be a silicone-based release agent or a non-silicone-based release agent.
  • silicone-based release agent examples include known silicone-based resins.
  • non-silicone release agents include long-chain alkyl pendant polymers obtained by reacting polyvinyl alcohol or ethylene-vinyl alcohol copolymers with long-chain alkyl isocyanates, olefin resins (e.g., copolymerized polyethylene, cyclic polyolefins, polymethylpentene, etc.), polyarylate resins (e.g., polycondensates of aromatic dicarboxylic acid components and dihydric phenol components, etc.), and fluororesins (e.g., polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), copolymers of tetrafluoroethylene and perfluoroalkoxyethylene (PFA), copolymers of tetrafluoroethylene and hexafluoropropylene (FEP), copolymers of te
  • the release layer may further contain additives as necessary.
  • additives include fillers, lubricants (waxes, fatty acid esters, fatty acid amides, etc.), stabilizers (antioxidants, heat stabilizers, light stabilizers, etc.), flame retardants, viscosity adjusters, thickeners, defoamers, ultraviolet absorbers, etc.
  • the thickness of the release layer is not particularly limited as long as it provides the desired releasability, but it is preferably within the range of 0.1 to 1.0 ⁇ m.
  • the thickness of the substrate is not particularly limited, but is preferably within the range of 10 to 100 ⁇ m, and more preferably within the range of 25 to 50 ⁇ m.
  • the method for applying the dope is not particularly limited, and examples thereof include known methods such as back coating, gravure coating, spin coating, wire bar coating, and roll coating. Among these, the back coating method is preferred from the viewpoint of forming a coating film that is thin and has a uniform thickness.
  • the dope applied to the substrate is dried. Drying methods include, for example, blowing air or heating. Among these, drying by blowing air is preferred from the viewpoint of easily suppressing curling of the laminated film.
  • the drying conditions e.g., drying temperature, solvent concentration in the atmosphere, drying time, etc.
  • the amount of residual solvent in the coating film after drying i.e., the optical film
  • the distribution state of the rubber particles in the optical film can be adjusted by adjusting the drying conditions. Specifically, from the viewpoint of making it easier to unevenly distribute the rubber particles, it is preferable to use a solvent that has good affinity with the rubber particles, to set the drying temperature high, and to set the solvent concentration in the atmosphere low.
  • the drying temperature is preferably within the range of (Tb-50) to (Tb+50)°C, and more preferably within the range of (Tb-40) to (Tb+40)°C, where Tb is the boiling point of the solvent (°C).
  • Tb is the boiling point of the solvent (°C).
  • the drying temperature is preferably 40°C or higher.
  • the solvent concentration in the atmosphere during drying is preferably in the range of 0.10 to 0.30 mass%, and more preferably 0.10 to 0.20 mass%. By making it 0.10 mass% or more, excessive evaporation of the solvent can be prevented, making it less likely for the coating film to crack. Furthermore, by making it 0.30 mass% or less, the evaporation rate of the solvent from the coating film can be increased appropriately, making it easier for the rubber particles to be unevenly distributed on the surface.
  • the solvent concentration in the atmosphere can be adjusted by the drying temperature and the dew point temperature inside the drying oven. Furthermore, the solvent concentration in the atmosphere can be measured with an infrared gas concentration meter.
  • the optical film according to the present invention is obtained by peeling off the substrate from the laminate film of the substrate and optical film thus obtained.
  • T A and T B satisfy the following formula (1) and both T A and T B are within the range of 39 to 89%.
  • the average light transmittance in the wavelength region of 380 to 780 nm can be measured by the following method. Each optical film is conditioned for 24 hours in an air-conditioned room at a temperature of 23° C. and a relative humidity of 55 RH. Then, in accordance with JIS K-7375:2008, a total light transmittance of each wavelength in the wavelength region of 380 to 780 nm is measured using a UV-visible spectrophotometer (for example, “UV-2450” (manufactured by Shimadzu Corporation)), and the arithmetic average value is calculated.
  • a UV-visible spectrophotometer for example, “UV-2450” (manufactured by Shimadzu Corporation)
  • optical film A When the laminate of the present invention is attached to a display device so that optical film A is positioned closer to the viewing side than optical film B, pen input to the display device is performed from the optical film A side.
  • optical film B suppresses the outward tensile stress acting on the back surface of the thin glass (the back surface when the surface closer to the viewing side is considered the front surface), thereby preventing the thin glass from bending and breaking (impact resistance).
  • the storage modulus of the optical film A at 25° C. is preferably 2.0 GPa or more.
  • the storage modulus of the optical film B at 25° C. is preferably within a range of 0.1 to 3.5 GPa, and more preferably within a range of 1.0 to 3.5 GPa, from the viewpoints of impact resistance and contrast after bending.
  • the loss tangent (tan ⁇ B ) of the optical film B at 25° C. is preferably within a range of 0.01 to 0.3, and more preferably within a range of 0.05 to 0.3.
  • the storage modulus and loss tangent of the optical film at 25°C can be adjusted by appropriately selecting the type and content of materials (resin, rubber particles, etc.).
  • the storage modulus and loss tangent at 25° C. of the optical film can be measured using a rheometer device “RSA-3” (manufactured by TA Instruments Japan Co., Ltd.) under the following test conditions.
  • Test conditions dynamic viscoelasticity test
  • Testing machine Dynamic viscoelasticity measuring device "RSA-3” (manufactured by TA Instruments Japan, Inc.)
  • Deformation method tension Preload load: 55g Temperature range: -70 to 200°C Frequency: 1.0Hz Displacement: ⁇ 0.1% Sample: Width 5mm Chuck distance: 20 mm
  • the optical film preferably has an in-plane retardation (R 0 ) represented by the following formula in the range of ⁇ 10 to 10 nm.
  • R 0 (Nx - Ny) x d
  • Nx is the maximum refractive index in the plane of the optical film
  • Ny is the minimum refractive index in the plane of the optical film
  • d is the thickness of the optical film.
  • the in-plane retardation (R 0 ) can be measured using an automatic birefringence meter, for example, an automatic birefringence meter "KOBRA (registered trademark)-21ADH” (manufactured by Oji Scientific Instruments Co., Ltd.) at a wavelength of 590 nm in an environment of a temperature of 23° C. and a humidity of 55% RH.
  • an automatic birefringence meter "KOBRA (registered trademark)-21ADH” (manufactured by Oji Scientific Instruments Co., Ltd.) at a wavelength of 590 nm in an environment of a temperature of 23° C. and a humidity of 55% RH.
  • the thickness of the optical film is preferably within the range of 10 to 60 ⁇ m, more preferably within the range of 15 to 50 ⁇ m, and even more preferably within the range of 20 to 40 ⁇ m.
  • the glass transition temperature of the optical film is preferably within the range of -30 to 180°C. If multiple glass transition temperatures are observed when measuring the glass transition temperature of the optical film, the lowest glass transition temperature observed shall be regarded as the glass transition temperature of the optical film.
  • the glass transition temperature (Tg) can be measured in accordance with JIS K 7121 (2012) using a DSC (Differential Scanning Colorimetry) device.
  • the glass layer according to the present invention is preferably a thin film glass from the viewpoint of excellent durability, flatness, etc.
  • materials for thin film glass include lithium aluminosilicate glass, soda-lime glass, borosilicate glass, silica glass, alkali metal aluminosilicate glass, and aluminosilicate glass with a low alkali content.
  • the thin film glass is preferably an alkali-free glass that contains substantially no alkali components.
  • the content of alkali components is preferably 1000 ppm by mass or less, more preferably 500 ppm by mass or less, and even more preferably 300 ppm by mass or less, relative to the total mass of the thin film glass.
  • the thickness of the thin film glass is preferably within a range of 10 to 50 ⁇ m.
  • the thickness of the thin film glass 10 ⁇ m or more, sufficient impact resistance of the laminate can be obtained.
  • the thickness of the thin film glass 50 ⁇ m or less sufficient flexibility of the laminate can be obtained.
  • the thinner the thin film glass is, the thinner the laminate can be, and the thinner the display device can be. From the viewpoint of achieving both impact resistance and contrast after bending, the thickness of the thin glass is more preferably within the range of 10 to 40 ⁇ m, and further preferably within the range of 10 to 30 ⁇ m.
  • Thin glass can be produced by a commonly known method, such as a float method, a down-draw method, an overflow down-draw method, etc.
  • the overflow down-draw method or the float method is preferred because the surface of the thin glass does not come into contact with the forming member during production, and the surface of the obtained thin glass is less likely to be scratched.
  • the float method is preferred from the viewpoint of obtaining a thin glass having a thickness in the range of 10 to 50 ⁇ m.
  • the thinner the glass the weaker it is and the more susceptible it is to breakage, making it difficult to handle and process thin-film glass on its own.
  • a thicker support substrate hereafter also referred to as a "carrier substrate”
  • peeling off the support substrate as a post-processing step
  • FIG. 4 is a schematic diagram showing an example of a method for producing thin-film glass.
  • Step 1 in step 1, a thin film glass 22 is prepared so that a first surface of the thin film glass is in contact with a carrier substrate 21 having a bonding surface. Then, a contact film 23 (also called a "contact film”) having adhesive force is pressure-bonded to a second surface opposite to the first surface.
  • the thin-film glass material is poured to the desired thickness onto a carrier substrate 21 that has sufficient strength and a thickness that is easy to process. This creates a first surface of the thin-film glass 22 that is in contact with the carrier substrate 21. After that, a contact film 23 is pressed onto a second surface on the opposite side to the first surface.
  • Step 2 As shown in FIG. 4, in step 2, the thin glass 22 is peeled off from the carrier substrate 21 by the contact film 23 having high adhesive strength.
  • Step 3 in step 3, a weakening treatment (electromagnetic radiation irradiation 24) is performed to weaken the adhesive strength of the contact film, thereby removing the contact film 23 from the second surface of the thin glass 22.
  • a weakening treatment electromagnettic radiation irradiation 24
  • the contact film 23 is used to safely hold the thin-film glass 22, thereby protecting the thin-film glass 22.
  • the exposed surface of the thin-film glass 22 can be protected from, for example, mechanical damage, and can be handled safely and easily.
  • Examples of materials for the contact film include polyolefins (PO) such as polyethylene terephthalate (PET) and polyethylene (PE).
  • PO polyolefins
  • PET polyethylene terephthalate
  • PE polyethylene
  • the contact film is usually adhered to the thin glass by an adhesive layer made of an adhesive provided on one side of the substrate.
  • the contact film may also be adhered directly to the thin glass by the adhesive properties of the contact film itself.
  • the adhesive strength between the contact film and the second surface of the thin film glass is appropriately selected so that the peeling device transmits sufficient force to peel the thin film glass from the carrier substrate.
  • the contact film is preferably in the form of a foil or tape. By forming it into a foil or tape, it can be wound into a roll.
  • the thickness of the contact film is preferably 50 ⁇ m or more, more preferably 80 ⁇ m or more, more preferably 125 ⁇ m or more, and particularly preferably 150 ⁇ m or more.
  • the thin glass is preferably fabricated on a carrier substrate by the aforementioned downdraw method, overflow downdraw method, or float method.
  • the thickness of the carrier substrate is preferably 100 ⁇ m or more, more preferably 300 ⁇ m or more, and even more preferably 500 ⁇ m or more. Furthermore, the width of the carrier substrate is preferably 3 inches or more (1 inch is 2.54 cm), more preferably 6 inches or more, even more preferably 8 inches or more, and particularly preferably 12 inches or more.
  • the carrier substrate is preferably equal to or larger than the first generation glass substrate size, for example, second to eighth generation sizes. Alternatively, it may be even larger, for example, 1x1m to 3x3m.
  • the carrier substrate may be of various shapes, such as rectangular, elliptical, circular, etc.
  • the thin glass film, together with the contact film, is peeled off from the carrier substrate by the adhesive force of the contact film.
  • the contact film is then peeled off, leaving a single thin glass film.
  • the adhesive strength of the contact film Before peeling the contact film from the thin glass, it is preferable to weaken the adhesive strength of the contact film by subjecting it to a treatment to weaken its adhesive strength. Specifically, it is preferable to reduce the adhesive strength to 0.5 N/25 mm or less.
  • electromagnetic radiation such as infrared, ultraviolet, or visible light
  • the electromagnetic radiation may be narrowband or may cover a wider band depending on the adhesive material used. It may also be laser radiation.
  • Some commercially available adhesive materials can be at least partially deactivated by exposure to electromagnetic radiation and can be used as contact films.
  • heat treatment may be used as a weakening treatment.
  • the electromagnetic radiation is preferably applied from the outer surface of the contact film, i.e., the side to which the thin glass is not adhered.
  • An example of a contact film is "NDS4150-20" (manufactured by Dao Ming Optical Co., Ltd.).
  • a corresponding weakening treatment is exposure to ultraviolet light with a wavelength of 365 nm.
  • the thin film glass for example, commercially available products manufactured by SCHOTT Co., Ltd., Nippon Electric Glass Co., Ltd., etc. can be used.
  • Adhesive layer refers to a layer having sufficient adhesiveness to attach the cover unit to the display unit or to bond each layer in the laminate. It is also a general term for adhesive layer C and adhesive layer D. The materials constituting the adhesive layer C and the adhesive layer D may or may not be the same.
  • the adhesive layer is preferably made of an adhesive. The adhesive that is preferably used will be described below.
  • the adhesive layer according to the present invention may be in the form of a film that can be rolled up, or in the form of a coating layer.
  • the coating layer is formed by applying an adhesive onto an adjacent layer and then curing the applied adhesive.
  • the adhesive is not particularly limited, and examples thereof include rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, urethane-based adhesives, vinyl alkyl ether-based adhesives, polyvinyl alcohol-based adhesives, polyvinylpyrrolidone-based adhesives, polyacrylamide-based adhesives, and cellulose-based adhesives.
  • acrylic-based adhesives are preferred.
  • Acrylic-based adhesives are excellent in transparency and adhesive properties (adhesion, cohesion, and adhesion). They are also excellent in weather resistance, heat resistance, and the like.
  • the term "acrylic pressure-sensitive adhesive” refers to a pressure-sensitive adhesive that contains an acrylic polymer as a base polymer.
  • Adhesive layer C The laminate of the present invention preferably further comprises an adhesive layer C.
  • the layers are preferably arranged in the order of the optical film A, the glass layer, the optical film B, and the adhesive layer C, as shown in FIG.
  • T B and T C when the average light transmittances in the wavelength region of 380 to 780 nm of the optical film B and the adhesive layer C are T B and T C , respectively, it is preferable that T B and T C satisfy the following formula (2). Equation (2): TB ⁇ TC
  • the laminate By further providing an adhesive layer C on the side of the laminate closest to the display device, the laminate can be attached to the display device.
  • optical film B can suppress the outward tensile stress acting on the back surface of the thin film glass (the back surface when the surface closer to the viewing side is considered the front surface), it is possible to prevent the thin film glass from bending and breaking (impact resistance).
  • adhesive layer C adjacent to optical film B, the outward tensile stress acting on the back surface of the thin film glass can be further suppressed.
  • the adhesive layer C can also contain a colorant to adjust the light transmittance.
  • a colorant can reduce the adhesive strength.
  • Adhesive layer D The laminate of the present invention preferably further comprises an adhesive layer D.
  • the layers are preferably arranged in the order of the optical film A, the glass layer, the adhesive layer D, and the optical film B.
  • the layers are preferably arranged in the order of the optical film A, the glass layer, the adhesive layer D, the optical film B, and the adhesive layer C, as shown in FIG.
  • the storage modulus of the adhesive layer D at 25°C is within the range of 0.5 to 8 MPa.
  • the pen input is performed from the optical film A side.
  • the outward tensile stress acting on the back surface of the thin film glass (the back surface when the surface closer to the viewing side is considered the front surface) can be suppressed, it is possible to prevent the thin film glass from bending and breaking (impact resistance).
  • the outward tensile stress acting on the back surface of the thin film glass can be further suppressed.
  • the adhesive layer made of an acrylic adhesive is preferably a layer formed by, for example, ultraviolet curing (ultraviolet polymerization) of an ultraviolet-curable acrylic adhesive. Note that, by ultraviolet curing (ultraviolet polymerization) of an ultraviolet-curable acrylic adhesive, a (meth)acrylic polymer is generated.
  • the "ultraviolet-curable acrylic adhesive” preferably contains a monomer component containing alkyl (meth)acrylate or a partial polymer of the monomer component, a photopolymerization initiator, etc.
  • the adhesive layer By appropriately adjusting the light transmittance of the adhesive layer, the adhesive layer can also be given a part of the function of a polarizing plate, specifically, the reflection of external light can be further suppressed. Furthermore, when the laminate is used as a cover glass unit of a display device, sufficient contrast can be obtained.
  • the light transmittance can be adjusted by adding a colorant to the adhesive layer (ultraviolet-curable acrylic adhesive).
  • the colorant may be the same as that used in the optical film.
  • the content of the colorant is preferably 1.02 mass % or less based on the total mass of the adhesive layer.
  • the UV-curable acrylic pressure-sensitive adhesive has as its base polymer a (meth)acrylic polymer obtained by UV-curing (UV-polymerizing) a monomer component containing an acrylate or a partial polymer of the monomer component.
  • the alkyl (meth)acrylate contained in the monomer component and other monomers that may be contained will be described below.
  • the other monomers that may be contained are preferably monofunctional monomers, but may also be polyfunctional monomers.
  • alkyl (meth)acrylate refers to acrylic and methacrylic, and is a general term for both.
  • alkyl (meth)acrylate refers to alkyl acrylate and alkyl methacrylate, and is a general term for both.
  • the alkyl (meth)acrylate according to the present invention is preferably an alkyl (meth)acrylate having a linear or branched alkyl group having 1 to 24 carbon atoms at the ester terminal. These may be used alone or in combination of two or more.
  • alkyl (meth)acrylates include alkyl (meth)acrylates having a branched alkyl group having 4 to 9 carbon atoms. Specific examples include n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, and isononyl (meth)acrylate. These may be used alone or in combination of two or more.
  • the content of alkyl (meth)acrylate having an alkyl group having 1 to 24 carbon atoms at the ester end is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more, based on the total mass of the monomer components.
  • Examples of monofunctional copolymerizable monomers (monofunctional monomers) other than alkyl (meth)acrylates include cyclic nitrogen-containing monomers.
  • the cyclic nitrogen-containing monomer is not particularly limited as long as it has a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group, and has a cyclic nitrogen structure.
  • the cyclic nitrogen structure is preferably one having a nitrogen atom in the cyclic structure.
  • Examples of the cyclic nitrogen-containing monomer include lactam-based vinyl monomers such as N-vinyl-2-pyrrolidone, N-vinyl- ⁇ -caprolactam, and methylvinylpyrrolidone, and vinyl-based monomers having a nitrogen-containing heterocycle such as vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, and vinylmorpholine. Also included are (meth)acrylic monomers containing a heterocycle such as a morpholine ring, a piperidine ring, a pyrrolidine ring, and a piperazine ring. Specific examples include N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, and N-acryloylpyrrolidine. Among these, lactam vinyl monomers are preferred.
  • the content of the cyclic nitrogen-containing monomer is preferably 0.5 to 50 mass%, more preferably 0.5 to 40 mass%, and even more preferably 0.5 to 30 mass%, based on the total mass of the monomer components.
  • a monofunctional monomer is a hydroxyl group-containing monomer.
  • the hydroxyl group-containing monomer has a polymerizable functional group with an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, and also has a hydroxyl group.
  • hydroxy group-containing monomer examples include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate; and hydroxyalkyl cycloalkane (meth)acrylates such as (4-hydroxymethylcyclohexyl)methyl (meth)acrylate.
  • hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxy
  • hydroxyethyl (meth)acrylamide examples include hydroxyethyl (meth)acrylamide, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether.
  • hydroxyalkyl (meth)acrylates are preferred. These may be used alone or in combination of two or more.
  • the content of the hydroxyl group-containing monomer is preferably within the range of 1 to 30% by mass, more preferably within the range of 2 to 27% by mass, and even more preferably within the range of 3 to 25% by mass, based on the total mass of the monomer components.
  • monofunctional monomers include carboxyl group-containing monomers and monomers having cyclic ether groups.
  • carboxyl group-containing monomer there are no particular limitations on the carboxyl group-containing monomer, so long as it has a polymerizable functional group with an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, and also has a carboxyl group.
  • carboxy group-containing monomer examples include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, etc.
  • itaconic acid or maleic acid may be an anhydride thereof.
  • acrylic acid or methacrylic acid is preferred, and acrylic acid is more preferred. These may be used alone or in combination of two or more.
  • the monomer having a cyclic ether group is not particularly limited as long as it has a polymerizable functional group having an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, and also has a cyclic ether group, such as an epoxy group or an oxetane group.
  • Examples of epoxy group-containing monomers include glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, etc.
  • Examples of oxetane group-containing monomers include 3-oxetanylmethyl (meth)acrylate, 3-methyl-oxetanylmethyl (meth)acrylate, 3-ethyl-oxetanylmethyl (meth)acrylate, 3-butyl-oxetanylmethyl (meth)acrylate, 3-hexyl-oxetanylmethyl (meth)acrylate, etc. These may be used alone or in combination of two or more.
  • the content of the carboxyl group-containing monomer or the monomer having a cyclic ether group is preferably 30% by mass or less, more preferably 27% by mass or less, and even more preferably 25% by mass or less, based on the total mass of the monomer components.
  • alkyl (meth)acrylates represented by CH 2 ⁇ C(R 1 )COOR 2 (R 1 represents a hydrogen atom or a methyl group, and R 2 represents a substituted alkyl group having 1 to 3 carbon atoms or a cyclic cycloalkyl group).
  • alkyl (meth)acrylate represented by CH 2 ⁇ C(R 1 )COOR 2 examples include phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, and isobornyl (meth)acrylate. These may be used alone or in combination of two or more.
  • the content of the alkyl (meth)acrylate represented by the above CH 2 ⁇ C(R 1 )COOR 2 is preferably 50 mass% or less, more preferably 45 mass% or less, and even more preferably 40 mass% or less, based on the total mass of the monomer components.
  • monofunctional monomers include, for example, vinyl acetate, vinyl propionate, styrene, ⁇ -methylstyrene; glycol-based acrylic ester monomers such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; acrylic ester monomers such as tetrahydrofurfuryl (meth)acrylate, fluorine (meth)acrylate, silicone (meth)acrylate, and 2-methoxyethyl acrylate; amide group-containing monomers, amino group-containing monomers, imide group-containing monomers, N-acryloylmorpholine, and vinyl ether monomers. Also included are monomers having a cyclic structure such as terpene (meth)acrylate and dicyclopentanyl (meth)acrylate.
  • silane-based monomers containing a silicon atom examples include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, and 10-acryloyloxydecyltriethoxysilane.
  • monomers may contain polyfunctional monomers as necessary in order to adjust the cohesive strength of the adhesive layer.
  • polyfunctional monomer there are no particular limitations on the polyfunctional monomer, so long as it is a monomer that has at least two polymerizable functional groups with unsaturated double bonds, such as (meth)acryloyl groups or vinyl groups.
  • polyfunctional monomers include ester compounds of polyhydric alcohols and (meth)acrylic acid such as (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tetramethylolmethane tri(meth)acrylate; allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane tri(
  • trimethylolpropane tri(meth)acrylate hexanediol di(meth)acrylate, or dipentaerythritol hexa(meth)acrylate is preferred. These may be used alone or in combination of two or more.
  • the content of the polyfunctional monomer varies depending on the molecular weight, the number of functional groups, etc., but is preferably 3 mass% or less, more preferably 2 mass% or less, and even more preferably 1 mass% or less, relative to the total mass of the monofunctional monomer.
  • the content of the polyfunctional monomer is preferably 0.001 mass% or more.
  • the monomer component may contain a partial polymer of the above monomer component.
  • the ultraviolet-curable acrylic pressure-sensitive adhesive according to the present invention preferably contains a photopolymerization initiator. By including a photopolymerization initiator, the monomer components can be polymerized sufficiently.
  • the photopolymerization initiator is not particularly limited as long as it generates radicals by ultraviolet light and initiates photopolymerization, and any commonly used photopolymerization initiator can be suitably used. Examples include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, ⁇ -ketol-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, and acylphosphine oxide-based photopolymerization initiators.
  • bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide examples include, for example, “Omnirad (registered trademark) 819" (manufactured by IGM Resins B.V.)), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (commercially available products include, for example, "Omnirad (registered trademark) TPO H” (manufactured by IGM Resins B.V.)), and the like. These may be used alone or in combination of two or more.
  • the content of the photopolymerization initiator is preferably within the range of 0.005 to 0.5% by mass, and more preferably within the range of 0.02 to 0.1% by mass, based on the total mass of the monomer components. By being within the above range, ultraviolet curing (ultraviolet polymerization) can proceed sufficiently.
  • the ultraviolet-curable acrylic pressure-sensitive adhesive according to the present invention may further contain a silane coupling agent, a crosslinking agent, and the like.
  • Silane coupling agents include, for example, epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl- ⁇ -aminopropyltrimethoxysilane; (meth)acrylic group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; and isocyan
  • the content of the silane coupling agent is preferably 1% by mass or less, more preferably in the range of 0.01 to 1% by mass, and even more preferably in the range of 0.02 to 0.6% by mass, based on the total mass of the monomer components.
  • crosslinking agent examples include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, silicone-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, silane-based crosslinking agents, alkyl etherified melamine-based crosslinking agents, metal chelate-based crosslinking agents, peroxides, etc.
  • isocyanate-based crosslinking agents are preferred. These may be used alone or in combination of two or more.
  • An isocyanate crosslinking agent is a compound that has two or more isocyanate groups (including isocyanate regenerating functional groups in which the isocyanate group is temporarily protected by a blocking agent or by polymerization, etc.) in one molecule.
  • isocyanate crosslinking agents include aromatic isocyanates such as tolylene diisocyanate and xylylene diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; and aliphatic isocyanates such as hexamethylene diisocyanate.
  • the content of the crosslinking agent is preferably 5% by mass or less, more preferably in the range of 0.01 to 5% by mass, even more preferably in the range of 0.01 to 4% by mass, and particularly preferably in the range of 0.02 to 3% by mass, based on the total mass of the monomer components.
  • the UV-curable acrylic adhesive may contain other additives as appropriate depending on the application.
  • additives include tackifiers (e.g., rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenolic resins, etc. that are solid, semi-solid, or liquid at room temperature); fillers such as hollow glass balloons; plasticizers; antioxidants; antioxidants, etc.
  • the viscosity of the UV-curable acrylic adhesive can be adjusted, for example, by adding various polymers such as thickening additives, polyfunctional monomers, etc., or by partially polymerizing the monomer components in the UV-curable acrylic adhesive.
  • the partial polymerization may be carried out before or after adding various polymers such as thickening additives, polyfunctional monomers, etc.
  • the viscosity of the ultraviolet-curable acrylic adhesive varies depending on the content of additives, etc. Therefore, the polymerization rate when the monomer components in the ultraviolet-curable acrylic adhesive are partially polymerized cannot be uniquely determined.
  • the polymerization rate is preferably 20% or less, more preferably within the range of 3 to 20%, and even more preferably within the range of 5 to 15%.
  • the viscosity can be adjusted to a level suitable for application work.
  • the adhesive layer can be produced by applying an ultraviolet-curable acrylic adhesive onto an adjacent layer, and irradiating it with ultraviolet light to cause ultraviolet curing (ultraviolet polymerization).
  • an ultraviolet-curable acrylic adhesive may be applied onto a substrate, and then ultraviolet light may be irradiated to cause ultraviolet curing (ultraviolet polymerization) to produce a film-like adhesive layer.
  • the substrate is not particularly limited, and examples include release films, transparent resin films, etc.
  • release films include release resin films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films; porous materials such as paper, cloth, and nonwoven fabric; and thin materials such as nets, foam sheets, metal foils, and laminates of these.
  • resin films are preferred from the viewpoint of excellent surface smoothness.
  • release resin films 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, ethylene-vinyl acetate copolymer film, etc.
  • the thickness of the release film is preferably within the range of 5 to 200 ⁇ m, and more preferably within the range of 5 to 100 ⁇ m.
  • the release film is preferably subjected to a release treatment using a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent. It is also preferable to perform an anti-soiling treatment using silica powder or the like. In addition, anti-static treatments such as coating, kneading or deposition may be performed. In particular, release treatment using a silicone-based, fluorine-based or long-chain alkyl-based release agent makes it easier to peel off the film-like adhesive layer.
  • the transparent resin film is not particularly limited, but is preferably transparent and composed of a single layer film.
  • transparent resin films include polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate, acetate-based resins, polyethersulfone-based resins, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyolefin-based resins, (meth)acrylic-based resins, polyvinyl chloride-based resins, polyvinylidene chloride-based resins, polystyrene-based resins, polyvinyl alcohol-based resins, polyarylate-based resins, and polyphenylene sulfide-based resins.
  • polyester resins, polyimide resins, and polyethersulfone resins are preferred.
  • the thickness of the transparent resin film is preferably within the range of 2 to 200 ⁇ m, and more preferably within the range of 20 to 188 ⁇ m.
  • the method for applying the UV-curable acrylic adhesive is not particularly limited, and any conventionally known method can be used.
  • application methods include roll coating, kiss roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and die coater methods.
  • the illuminance of the ultraviolet light irradiated to the ultraviolet-curable acrylic adhesive is preferably within the range of 5 to 200 mW/ cm2 .
  • the polymerization reaction time can be shortened, resulting in excellent productivity.
  • the photopolymerization initiator can be prevented from being rapidly consumed.
  • the polymerization proceeds sufficiently, and a high molecular weight polymer ((meth)acrylic polymer) can be obtained. This allows the adhesive layer to have excellent holding power, especially at high temperatures.
  • the integrated amount of ultraviolet light is preferably within the range of 100 to 5000 mJ/ cm2 .
  • the ultraviolet lamp used in the present invention is not particularly limited, but is preferably an LED lamp.
  • the LED lamp emits less heat than other ultraviolet lamps, so that the temperature rise during the ultraviolet curing of the ultraviolet curing acrylic adhesive can be suppressed. This allows a polymer with a high molecular weight to be obtained, and an adhesive layer with sufficient cohesive strength can be obtained, thereby increasing the holding power at high temperatures when the adhesive sheet is made.
  • the ultraviolet lamp may be a combination of a plurality of ultraviolet lamps.
  • ultraviolet light may be intermittently irradiated, and a light period during which ultraviolet light is irradiated and a dark period during which ultraviolet light is not irradiated may be provided.
  • the final polymerization rate of the monomer components in the UV-curable acrylic adhesive is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.
  • the peak wavelength of the ultraviolet light irradiated onto the ultraviolet-curing acrylic adhesive is preferably within the range of 200 to 500 nm, and more preferably within the range of 300 to 450 nm.
  • the peak wavelength of the ultraviolet light is 500 nm or less, the photopolymerization initiator decomposes and the polymerization reaction begins.
  • the peak wavelength of the ultraviolet light is 200 nm or more, the scission of the polymer chain can be suppressed, and sufficient adhesion can be obtained.
  • Methods for blocking oxygen include creating a release film on the coating layer of the UV-curable acrylic adhesive, and carrying out the polymerization reaction in a nitrogen atmosphere.
  • release films include the release films mentioned above.
  • the storage modulus of the adhesive layer at 25° C. is preferably within the range of 0.5 to 10.0 MPa, and more preferably within the range of 1.2 to 8.0 MPa.
  • the storage modulus of adhesive layer D at 25°C is within the range of 0.5 to 8 MPa.
  • the storage modulus of the adhesive layer at 25°C can be adjusted by appropriately selecting the type and content of materials (monomer components, UV absorbers, photopolymerization initiators, etc.), UV irradiation conditions, etc.
  • the storage modulus of the adhesive layer at 25° C. can be measured using a viscoelasticity measuring device "ARES-G2" (manufactured by TA Instruments Japan, Inc.) under the following test conditions.
  • Test conditions dynamic viscoelasticity test
  • Testing machine Viscoelasticity measuring device "ARES-G2” (manufactured by TA Instruments Japan, Inc.)
  • Deformation method Rotation Temperature range: -50 to 100°C Frequency: 1Hz
  • Displacement Strain 0.05%
  • Distance between chucks Automatically variable so that the load becomes 10 g (approximately equal to the sample thickness).
  • the thickness of the adhesive layer is preferably within the range of 2 to 60 ⁇ m, more preferably within the range of 2 to 20 ⁇ m, and even more preferably within the range of 5 to 15 ⁇ m, from the viewpoint of making the final laminate thinner.
  • the weight average molecular weight (Mw) of the resin material (e.g., (meth)acrylic polymer) used in the adhesive layer is preferably within the range of 100,000 to 5,000,000, and more preferably within the range of 200,000 to 1,000,000, from the viewpoint of controlling the storage modulus.
  • the weight average molecular weight (Mw) of the resin material used in the adhesive layer is preferably smaller than the weight average molecular weight (Mw) of the resin material used in the optical film. This allows the effects of the present invention to be obtained more efficiently.
  • the weight average molecular weight (Mw) of the resin material can be measured using a gel permeation chromatograph "HLC8220GPC” (manufactured by Tosoh Corporation) and columns “TSK-GEL G6000", “HXL-G5000”, “HXL-G5000”, “HXL-G4000”, and “HXL-G3000HXL” (all manufactured by Tosoh Corporation, in series). 20 mg ⁇ 0.5 mg of a sample is dissolved in 10 mL of tetrahydrofuran and filtered through a 0.45 mm filter. 100 mL of this solution is then injected into a column (temperature 40° C.) and measured with an RI detector at a temperature of 40° C., and the value is expressed in terms of styrene.
  • the glass transition temperature (Tg) of the adhesive layer is preferably 0°C or lower, more preferably -10°C or lower, and even more preferably -20°C or lower, from the viewpoint of achieving both impact resistance in a low-temperature environment and contrast after bending.
  • the glass transition temperature (Tg) can be measured in accordance with JIS K 7121 (2012) using a DSC (Differential Scanning Colorimetry) device.
  • the manufacturing method of the laminate of the present invention is not particularly limited, and examples thereof include a method of sequentially arranging a glass layer (thin film glass), an optical film, and, if necessary, an adhesive layer (ultraviolet-curable acrylic adhesive).
  • T A and T B satisfy the above formula (1) and both T A and T B are within the range of 39 to 89%.
  • T C the average light transmittance of the adhesive layer C in the wavelength region of 380 to 780 nm
  • T B and T C satisfy the above formula (2).
  • the storage modulus of the adhesive layer D at 25°C is within the range of 0.5 to 8 MPa.
  • the thickness of the laminate of the present invention is preferably within the range of 30 to 110 ⁇ m, and more preferably within the range of 55 to 95 ⁇ m, from the viewpoint of achieving both impact resistance and contrast after bending.
  • Display Device The display device of the present invention is characterized by comprising the laminate of the present invention. It is also preferable that the optical film A is disposed closer to the viewing side of the display device than the optical film B.
  • the display device of the present invention can be obtained by attaching the laminate (cover unit) of the present invention to the surface of the display device (display unit) described below.
  • the attachment method is not particularly limited, but it is preferable to use an adhesive to attach them together.
  • the adhesive is not particularly limited, but from the viewpoints of impact resistance and contrast after bending, it is preferable to use a laminate having the above-mentioned adhesive layer as the cover unit.
  • the display device of the present invention may also have a polarizing plate between the laminate of the present invention (cover unit) and the display device (display unit) described below.
  • the laminate of the present invention can suppress external light reflection, that is, since the laminate of the present invention has some of the functions of a polarizing plate, it does not necessarily have to have a polarizing plate.
  • the term "display device” refers to a device having a display mechanism, and has a light-emitting element or a light-emitting device as a light source.
  • the display device include a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, a touch panel display device, an electron emission display device (such as a field emission display device (FED) and a surface field emission display device (SED)), an electronic paper (a display device using electronic ink or an electrophoretic element), a plasma display device, a projection type display device (such as a grating light valve (GLV) display device and a display device having a digital micromirror device (DMD)), a piezoelectric ceramic display, and the like.
  • the liquid crystal display device include a transmissive liquid crystal display device, a semi-transmissive liquid crystal display device, a reflective liquid crystal display device, a direct-view liquid crystal display device, and a
  • These display devices may be display devices that display two-dimensional images, or may be stereoscopic display devices that display three-dimensional images.
  • an organic EL display device or a touch panel display device is preferable, and an organic EL display device is more preferable.
  • the display device of the present invention is equipped with the laminate (cover unit) of the present invention, which makes it possible to suppress external light reflection during use and to obtain good contrast even after bending. It also provides good impact resistance that is compatible with pen input.
  • FIG. 5 and 6 show an example of application of the present invention to an organic EL display, which is an example of a display device.
  • a laminate 20 is disposed on an organic EL layer 101 via an adhesive layer C4. If necessary, other layers such as an adhesive layer D may be disposed as shown in Fig. 6.
  • an organic EL display is composed of an organic EL layer consisting of an electrode/electron transport layer/light-emitting layer/hole transport layer/transparent electrode, and a polarizing plate equipped with a retardation plate (lambda/4 plate) to improve image quality.
  • a polarizing plate equipped with a retardation plate (lambda/4 plate) to improve image quality.
  • the laminate of the present invention has some of the functions of a polarizing plate, it does not necessarily have to have a polarizing plate.
  • the display device of the present invention may also be a foldable display.
  • a foldable display is preferably a single continuous display that can be folded in half when carried, reducing its size by half and improving portability. It is further preferable that the foldable display is thin and lightweight.
  • the laminate of the present invention not only suppresses external light reflection, but also has good impact resistance and is less likely to leave creases even when folded repeatedly. It also maintains contrast even after repeated folding. Therefore, in a foldable display, it is excellent in visibility after repeated folding, specifically in suppressing image distortion at the folded parts.
  • the average light transmittance in the visible light region of the optical film and the adhesive layer C was measured by the following method.
  • the storage modulus of the adhesive layer D was measured by the following method.
  • Each optical film was conditioned for 24 hours in an air-conditioned room at a temperature of 23° C. and a relative humidity of 55 RH. Then, in accordance with JIS K-7375:2008, a UV-visible spectrophotometer (for example, “UV-2450” (manufactured by Shimadzu Corporation)) was used to measure the total light transmittance of each wavelength in the wavelength range of 380 to 780 nm, and the arithmetic average value was calculated.
  • a UV-visible spectrophotometer for example, “UV-2450” (manufactured by Shimadzu Corporation)
  • ester compound 1 A dehydration condensation reaction was carried out for 15 hours, and after completion of the reaction, unreacted 1,2-propylene glycol was distilled off under reduced pressure at 200° C. to obtain ester compound 1.
  • the acid value of the ester compound 1 was 0.10, and the number average molecular weight was 450.
  • the cellulose ester film web was slit to a width of 1.7 m after evaporating the solvent at 35°C. It was then stretched in the TD direction (width direction of the film) by 1.3 times (stretching ratio of 30%) with a tenter while drying at a drying temperature of 160°C (also called the "heat treatment temperature” or “stretching temperature”). At this time, the amount of residual solvent (also called “residual solution”) when stretching with the tenter started was 20%. It was then dried for 15 minutes while being transported by multiple rolls in a drying device at 120°C.
  • optical film A1 It was then slit to a width of 2.2 m, knurled at both ends of the film to a width of 15 mm and a height of 10 ⁇ m, and wound around a core to obtain optical film A1.
  • the amount of residual solvent in the optical film was 0.2%, the thickness was 40 ⁇ m, and the number of windings was 6000 m.
  • Optical films A2 to A5 and A7 to A11 were prepared in the same manner as in preparation of optical film A1, except that the type of resin, the type and content of rubber particles, the type and content of colorant, and the thickness of the optical film were changed as shown in Tables I to IV. Further, an optical film A6 was prepared in the same manner as in the preparation of the optical film B1, except that the content of the colorant was changed as shown in Tables I to IV.
  • solution I The following components were charged into an 8 L polymerization apparatus equipped with a stirrer to prepare solution I.
  • Deionized water 180 parts by weight Polyoxyethylene lauryl ether phosphate 0.002 parts by weight Boric acid 0.473 parts by weight Sodium carbonate 0.047 parts by weight Sodium hydroxide 0.008 parts by weight
  • a monomer mixture (c') consisting of the following components was prepared.
  • Methyl methacrylate (methyl methacrylate) 84.6% by mass
  • n-Butyl acrylate (n-butyl acrylate) 5.9% by mass
  • Styrene 7.9% by mass
  • Allyl methacrylate (allyl methacrylate) 0.5% by mass n-Octyl mercaptan 1.1% by mass
  • the following ingredients were then added: Potassium persulfate (added as a 2% by weight aqueous solution) 0.012 parts by weight
  • the polymerization reaction was continued for 120 minutes to obtain a soft layer (a layer made of acrylic rubber-like polymer (a)).
  • the glass transition temperature (Tg) of the soft layer calculated by averaging the glass transition temperatures of the homopolymers of the monomers constituting the acrylic rubber-like polymer (a) according to the composition ratio, was -30°C.
  • a monomer mixture (b') consisting of the following components was prepared.
  • Methyl methacrylate (methyl methacrylate) 97.5% by mass
  • n-Butyl acrylate (n-butyl acrylate) 2.5% by mass
  • the obtained methacrylic polymer (b) was poured into a 3% by mass aqueous solution of sodium sulfate to cause salting out and coagulation. Then, after repeated dehydration and washing, the mixture was dried to obtain acrylic graft copolymer particles (rubber particles) R1 having a three-layer structure.
  • the average particle size of the obtained rubber particles R1 was measured by a zeta potential/particle size measuring system "ELSZ-2000ZS" (manufactured by Otsuka Electronics Co., Ltd.) and found to be 200 nm.
  • the glass transition temperature (Tg) of the rubber particles was -30°C.
  • Optical Film B1 As a substrate, a PET film "TN100" (manufactured by Toyobo Co., Ltd., thickness 50 ⁇ m, with a release layer containing a non-silicone-based release agent) was prepared. A dope was applied onto the release layer of this PET film using a die by a backcoat method, and then dried at 80°C under an atmosphere with a solvent concentration of 0.18% by volume. Then, the substrate was peeled off to obtain an optical film B1 with a thickness of 40 ⁇ m.
  • TN100 manufactured by Toyobo Co., Ltd., thickness 50 ⁇ m, with a release layer containing a non-silicone-based release agent
  • Optical films B2 to B19 were prepared in the same manner as in preparation of optical film B1, except that the type of resin, the type and content of rubber particles, the type and content of colorant, and the thickness of the optical film were changed as shown in Tables I to IV.
  • Optical film B20 was prepared in the same manner as in preparation of optical film B1, except that the dope was directly applied to glass layer 1 described below, instead of using a PET film as the substrate.
  • Step 1 A thin film glass was prepared so that a first surface of the thin film glass was in contact with a carrier substrate having a bonding surface. Then, a contact film having adhesive force was attached to a second surface of the thin film glass opposite to the first surface. (Step 2) The thin glass was then peeled off from the carrier substrate by the highly adhesive contact film. (Step 3) The contact film was removed from the second surface of the thin glass peeled off from the carrier substrate by a weakening treatment (electromagnetic radiation exposure) that weakened the adhesive strength of the contact film.
  • a weakening treatment electromagagnetic radiation exposure
  • step 1 a thin glass film was prepared so as to be in contact with a carrier substrate having a thickness of 500 ⁇ m and to have a predetermined thickness, and then a contact film was attached to the thin glass film.
  • step 2 the thin glass film together with the contact film was peeled off from the carrier substrate in 30 seconds.
  • the contact film used was a commercially available product, "NDS4150-20.”
  • NDS4150-20 is a 150 ⁇ m thick film containing polyolefin (PO), and further has a 10 ⁇ m thick adhesive layer.
  • step 3 the exposed contact film was subjected to a weakening treatment to reduce the adhesive strength.
  • a weakening treatment ultraviolet light with a wavelength of 365 nm was irradiated onto the contact film for 10 seconds.
  • the illuminance of the ultraviolet light was 500 mW/cm 2
  • the cumulative amount of light was 500 mJ/cm 2 .
  • the adhesive strength before the weakening treatment was 11 N/25 mm, but after the weakening treatment, the adhesive strength was reduced to 0.4 N/25 mm. This allowed the contact film to be easily peeled off from the thin glass, and a glass layer 1 (thin glass 1) with a thickness of 30 ⁇ m was obtained.
  • Adhesive Layer C (4.1) Preparation of Adhesive Layer C1 (4.1.1) Preparation of UV-Curable Acrylic Adhesive Composition (a-1) A monomer mixture consisting of the following components was prepared. 2-Ethylhexyl acrylate (2EHA) 78 parts by weight N-vinyl-2-pyrrolidone (NVP) 18 parts by weight 2-hydroxyethyl acrylate (HEA) 4 parts by weight
  • Adhesive layers C2 and C3 were prepared in the same manner as in the preparation of adhesive layer C1, except that a colorant was further added and the type and content of the colorant were changed as shown in Tables I to IV.
  • the storage modulus of the adhesive layer D1 at 25° C. was 8.00 MPa.
  • a sample of the adhesive layer D was prepared by forming the adhesive layer D on the surface of a release film instead of the optical film in the same manner, and then peeling off the release film. Then, the storage modulus was measured.
  • Adhesive layers D2 and D3 were prepared in the same manner as in the preparation of adhesive layer D1, except that the thickness and storage modulus were changed as shown in Tables I to IV.
  • the storage modulus at 25° C. was 0.5 MPa and 11.00 MPa, respectively.
  • the storage modulus was adjusted by changing the ultraviolet ray irradiation conditions.
  • the front luminance (luminance measured from the normal direction of the display screen) of the display screen when the organic EL panel was displayed white was measured from a distance of 1 m using a spectroradiometer "CS2000" (manufactured by Konica Minolta Sensing Co., Ltd.) Similarly, the front luminance of the display screen when the organic EL panel was displayed black was measured.
  • CS2000 spectroradiometer
  • Front contrast (front luminance when white is displayed) / (front luminance when black is displayed) iii)
  • the front contrast was measured at any 10 points on the display screen of the organic EL panel, and the arithmetic mean value was calculated. Then, the contrast was evaluated according to the following criteria. If the evaluation was A or higher (A to AAA), the panel was deemed usable.
  • A: The front contrast is 1,500 or more and less than 1,700.
  • C The front contrast is less than 1,300.
  • AAA Will not break even when dropped from 30cm.
  • AA It will not break if dropped from 25 cm, but will break if dropped from 30 cm.
  • A It won't break if dropped from 15cm, but it will break if dropped from 25cm.
  • B It does not break when dropped from 10 cm, but it breaks when dropped from 15 cm.
  • C When dropped from 10 cm, tiny cracks were visible under a microscope.
  • D Cracks are visible when dropped from 10 cm.
  • TAC triacetyl cellulose
  • PET polyethylene terephthalate
  • COP cycloolefin resin
  • Arton G7810 manufactured by JSR Corporation
  • R1 Rubber particles obtained above (colorant)
  • P1 "Kayaset Black A-N” (manufactured by Nippon Kayaku Co., Ltd.)
  • P2 "NUBIAN BLACK PC-5857” (manufactured by Orient Chemical Industry Co., Ltd.)
  • the examples and comparative examples show that the laminate of the present invention can achieve both reflectance (suppression of external light reflection) and contrast (good contrast after bending).
  • a comparison of Examples 17 to 20 shows that impact resistance is improved when the rubber particle content is within the range of 10 to 80 mass % relative to the total mass of optical film B.
  • a comparison of Examples 22 to 25 shows that contrast and impact resistance are improved by setting the thickness of optical film B within the range of 15 to 50 ⁇ m.
  • Example 11 shows that even when the glass layer is 10 ⁇ m thick, the reflectance, contrast, and impact resistance are good.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Laminated Bodies (AREA)

Abstract

L'invention a pour objet de fournir un stratifié et un dispositif d'affichage qui concilient inhibition de réflexion de lumière naturelle et contraste satisfaisant après flexion.　Le stratifié de l'invention possède au moins un film optique (A), un film optique (B) et une couche de verre. Le stratifié de l'invention est caractéristique en ce que ledit film optique (A), ladite couche de verre et ledit film optique (B) sont disposés dans cet ordre. En outre, lorsque la transmission de lumière moyenne dans une région de longueur d'ondes de ３８０ à ７８０ｎｍ dudit film optique (A) et dudit film optique (B), est individuellement représentée par ＴＡ et ＴＢ, alors ladite ＴＡ et ladite ＴＢ satisfont la formule (1), et ladite ＴＡ et ladite ＴＢ se trouvent ensemble à l'intérieur d'une plage de ３９ à ８９％.　Formule （１）：　ＴＡ＞ＴＢ
PCT/JP2023/041404 2022-11-29 2023-11-17 Stratifié, et dispositif d'affichage WO2024116892A1 (fr)

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JP2022-190465 2022-11-29
JP2022190465 2022-11-29

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007010834A (ja) * 2005-06-29 2007-01-18 Sumitomo Chemical Co Ltd ディスプレイ用基板及びそれを用いたディスプレイ素子
JP2009279926A (ja) * 2008-04-24 2009-12-03 Nitto Denko Corp 可撓性基板
JP2016039135A (ja) * 2014-08-06 2016-03-22 三菱化学株式会社 フレキシブル基板及びそれを用いた有機ｅｌ素子、有機ｅｌ照明装置
WO2017066924A1 (fr) * 2015-10-20 2017-04-27 Schott Glass Technologies (Suzhou) Co. Ltd. Procédé de post-traitement d'article collé
JP2019031100A (ja) * 2018-11-01 2019-02-28 日東電工株式会社 積層体
JP2022028479A (ja) * 2020-08-03 2022-02-16 日東電工株式会社 複層構造体

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007010834A (ja) * 2005-06-29 2007-01-18 Sumitomo Chemical Co Ltd ディスプレイ用基板及びそれを用いたディスプレイ素子
JP2009279926A (ja) * 2008-04-24 2009-12-03 Nitto Denko Corp 可撓性基板
JP2016039135A (ja) * 2014-08-06 2016-03-22 三菱化学株式会社 フレキシブル基板及びそれを用いた有機ｅｌ素子、有機ｅｌ照明装置
WO2017066924A1 (fr) * 2015-10-20 2017-04-27 Schott Glass Technologies (Suzhou) Co. Ltd. Procédé de post-traitement d'article collé
JP2019031100A (ja) * 2018-11-01 2019-02-28 日東電工株式会社 積層体
JP2022028479A (ja) * 2020-08-03 2022-02-16 日東電工株式会社 複層構造体

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