WO2007088797A1 - Film destine a un element reflechissant de source lumineuse superficielle - Google Patents

Film destine a un element reflechissant de source lumineuse superficielle Download PDF

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Publication number
WO2007088797A1
WO2007088797A1 PCT/JP2007/051343 JP2007051343W WO2007088797A1 WO 2007088797 A1 WO2007088797 A1 WO 2007088797A1 JP 2007051343 W JP2007051343 W JP 2007051343W WO 2007088797 A1 WO2007088797 A1 WO 2007088797A1
Authority
WO
WIPO (PCT)
Prior art keywords
film
layer
light source
reflecting member
surface light
Prior art date
Application number
PCT/JP2007/051343
Other languages
English (en)
Japanese (ja)
Inventor
Yoshihiko Sakaguchi
Osamu Watanabe
Original Assignee
Toray Industries, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toray Industries, Inc. filed Critical Toray Industries, Inc.
Priority to CN2007800034434A priority Critical patent/CN101375185B/zh
Priority to JP2007509754A priority patent/JP5040647B2/ja
Priority to KR1020087016211A priority patent/KR101331888B1/ko
Publication of WO2007088797A1 publication Critical patent/WO2007088797A1/fr

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133605—Direct backlight including specially adapted reflectors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/08—Mirrors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • G02B6/0055—Reflecting element, sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • 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
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/402—Coloured
    • 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
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/406—Bright, glossy, shiny surface
    • 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
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/416—Reflective
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2457/00—Electrical equipment
    • B32B2457/20—Displays, e.g. liquid crystal displays, plasma displays
    • B32B2457/202—LCD, i.e. liquid crystal displays

Definitions

  • the present invention relates to a film for a light source reflecting member having a surface that is discriminated between one surface and the other surface. More preferably, the present invention relates to a film for a surface light source reflecting member that causes little decrease in luminance over time. Further, the present invention relates to a direct liquid crystal knock light for a liquid crystal display using the surface light source reflecting member film, a reverse prism liquid crystal backlight, and a lamp reflector for the backlight.
  • a backlight that illuminates a liquid crystal cell (hereinafter referred to as a liquid crystal backlight) is used.
  • the LCD monitor uses an edge-light type LCD backlight
  • the LCD TV uses a direct-type LCD backlight.
  • a film for a surface light source reflecting member (hereinafter referred to as a reflecting film) used for these liquid crystal backlights a porous white film formed by bubbles is generally used (Patent Document 1).
  • a white film having an ultraviolet absorbing layer laminated has been proposed in order to prevent yellow discoloration of the film due to ultraviolet rays emitted by cold cathode tube force (Patent Documents 2 and 3).
  • a white film is also proposed in which the glossiness on both sides of the film is controlled in order to provide adhesion (Patent Document 4).
  • Patent Document 1 Japanese Patent Application Laid-Open No. 8-262208
  • Patent Document 2 JP 2001-166295 A
  • Patent Document 3 Japanese Patent Laid-Open No. 2002-90515
  • Patent Document 4 JP 2005-125700 A
  • a reflective film is used by being attached to an aluminum plate or a stainless steel plate in a liquid crystal backlight manufacturing process.
  • the lamp reflector does not use a metal plate, but a reflective film alone.
  • functions are added to one side. Since the reflective film provided with such a layer is white on both sides, it is difficult to visually distinguish the surface provided with the function-imparting layer from the opposite surface. The difficulty of distinguishing these has caused problems such as extra time in the backlight manufacturing process and reduced productivity.
  • the resin containing a light stabilizer and Z or an ultraviolet absorber is mistakenly caused by these problems.
  • the surface with the layer may be stuck to an aluminum plate or a stainless steel plate. If it is applied by mistake, the surface without the light stabilizer and the resin layer containing Z or UV absorber will be exposed to the light of the cold cathode tube and deteriorate. As a result, the brightness of a product such as a liquid crystal television using the reflective film decreases with time during use, and a serious problem occurs.
  • the LCD backlight housing and the reflective film may come into contact with each other as shown in Fig. 2, and may be scratched.
  • the notebook PC to which the edge-light type backlight is applied is regarded as light weight, and the liquid crystal backlight housing is also provided with a hollow space for light weight.
  • edge light type backlights scratches on the reflective film can be seen through this cavity.
  • a liquid crystal backlight with visible scratches has a problem that the yield is lowered because the quality of the finished product is lowered.
  • the reverse prism type liquid crystal backlight uses a reflective film with high glossiness, and this problem is noticeable because it is easily noticeable if scratched.
  • the present invention employs the following means in order to solve the hard problem.
  • the film for a surface light source reflecting member of the present invention is composed of a white film, and the difference AG in gloss (60 °) between one surface and the other surface is AG> 80. It is.
  • the white film has a resin layer on one side and the light on the other side of the white film
  • the degree (60 °) is 90% or more.
  • the resin layer is a resin layer containing an ultraviolet absorber and Z or a light stabilizer.
  • the heat shrinkage rate in the film longitudinal direction and film width direction after heat treatment at 90 ° C for 30 minutes is 0.1% or more and 0.2% or less.
  • the white film is a three-layer structure consisting of A layer, ZB layer and ZA layer, B layer is a layer containing fine bubbles, and A layer contains polyester and inorganic particles and Z or organic particles.
  • the particle content of which is not more than 0.5% by weight with respect to the total weight of each A layer,
  • the white film has a three-layer composition of A layer, ZB layer, and ZC layer, B layer is a layer containing fine bubbles, and A layer and Z or C layer are polyester with inorganic particles and Z or organic particles.
  • a particle content of which is 0.5% by weight or less based on the total weight of each layer containing the particles,
  • the direct type liquid crystal knocklight, the liquid crystal knocklight lamp reflector, and the reverse prism type liquid crystal knocklight of the present invention use the surface light source reflecting member film of the present invention.
  • the film for a surface light source reflecting member of the present invention it is possible to easily distinguish between a surface provided with a function-imparting layer and a surface on the opposite side visually, and to improve productivity in a liquid crystal knocklight manufacturing process. Can do.
  • a resin layer containing an ultraviolet absorber and Z or a light stabilizer is provided as a function-imparting layer, a resin layer containing an ultraviolet absorber and Z or a light stabilizer is visually provided.
  • a resin layer containing an ultraviolet absorber and Z or a light stabilizer can be installed to face the cold cathode tube side. The decrease in luminance over time can be reduced.
  • the yield as an LCD backlight is less noticeable due to film scratches caused by contact between the backlight housing and the surface light source reflecting member film during assembly. Can be high.
  • FIG. 1 Direct type liquid crystal backlight using the film for surface light source reflecting member of the present invention.
  • FIG. 2 Reverse prism type liquid crystal knock light using the film for surface light source reflecting member of the present invention.
  • the present invention has the above-mentioned problem, that is, since a white film having a layer having a function provided on one side is white on both sides, the surface provided with the function-imparting layer is visually discriminated from the opposite side.
  • a white film having a layer having a function provided on one side is white on both sides, the surface provided with the function-imparting layer is visually discriminated from the opposite side.
  • the difference AG between the glossiness (60 °) of one side and the other side of the film for a surface light source reflecting member (hereinafter referred to as a reflective film) was set to AG> 80
  • AG> 80 As a result, it became easy to distinguish between the surface with the function-imparting layer and the surface on the opposite side, and it was clarified that the problems to be solved can be solved all at once.
  • a Suga Test Instruments digital variable gloss meter (UGV-4D) can be used for measurement.
  • the difference AG (60 °) in glossiness (60 °) between one surface and the other surface of the reflective film of the present invention is set to be greater than 80% in order to enable discrimination between the one surface and the other surface. There is a need. AG is preferably 85% or more, more preferably 90% or more. If AG is 80% or less, it will be difficult to identify the surface. There are the following methods to make AG larger than 80%. (1) Make a difference in glossiness between one side and the other side of the white film constituting the reflective film.
  • a resin layer is provided on one surface of the white film constituting the reflective film, and the luminous intensity of the surface is lowered.
  • the white film having a high molecular force used as the reflective film of the present invention preferably has a high visible light reflectance.
  • a white film containing bubbles inside is not particularly limited, but a porous unstretched film, a polypropylene film, or a polyester film is preferably exemplified.
  • a polyester film is particularly preferable as a white film according to the present invention because of its excellent heat resistance and rigidity.
  • the polyester constituting the white film according to the present invention is a polymer obtained by condensation polymerization of diol, dicarboxylic acid and force.
  • dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, adipic acid, and sebacic acid.
  • the diol is represented by ethylene glycol, trimethylene glycol, tetramethylene glycol, cyclohexane dimethanol and the like.
  • polymethylene terephthalate polytetramethylene terephthalate, polyethylene p-oxybenzoate, poly 1,4-cyclohexylene dimethylene terephthalate, and polyethylene 2,6 naphthalene dicarboxylate.
  • polyethylene terephthalate and polyethylene naphthalate are particularly preferable.
  • polyesters may be homopolyesters or copolyesters.
  • copolymer components include diol components such as diethylene glycol, neopentyl glycol, and polyalkylene glycol; Examples include acid components.
  • the polyester used in the white film according to the present invention is preferably polyethylene terephthalate.
  • Polyethylene terephthalate film has excellent water resistance, durability and chemical resistance.
  • the reflective film of the present invention preferably has an average reflectance in the wavelength range of 400 to 700 nm of 90% or more on at least one side of the reflective film.
  • the average reflectance refers to the reflectance when an integrating sphere is attached to a spectrophotometer (U-3310) manufactured by Hitachi High-Technologies and the standard white plate (acid aluminum) is 100%. Measured over ⁇ 700nm, read the reflectance at 5nm intervals from the obtained chart, and averaged values.
  • the average reflectance is 95% or more, more preferably 98% or more.
  • the average reflectance is not particularly limited but is preferably 108% or less. This is because in order to increase the average reflectance, it is necessary to increase the amount of nucleating agent, and in this case, the film forming property may become unstable.
  • the white film according to the present invention is preferably whitened by containing fine bubbles inside the film. Formation of fine bubbles is achieved by dispersing a polymer incompatible with a high melting point polyester in a film base material such as polyester and stretching it (for example, biaxial stretching). . During stretching, voids (bubbles) are formed around the incompatible polymer particles, which exhibit a scattering effect on light, and thus are whitened, and a high reflectance can be obtained.
  • Incompatible polymers include, for example, poly-3-methyl phthalene 1, poly-4-methyl pentene 1, polybutyl t-butane, 1,4 trans poly 2,3 dimethyl butadiene, polybutyl cyclohexane, polystyrene, polymethyl styrene, poly 200 ° C or higher melting point selected from dimethylstyrene, polyfluorostyrene, poly-2-methyl-4-fluorostyrene, polyvinyl-t-butyl ether, cellulose triacetate, cellulose tripropionate, polybulufluoride, polychlorofluoroethylene, etc.
  • polyolefin particularly polymethylpentene, is preferred for the polyester base material.
  • the addition amount of the incompatible polymer is preferably 5% by weight or more and 25% by weight or less when the entire layer containing the incompatible polymer is 100% by weight. If it is less than 5% by weight, the effect of whitening is diminished, and it becomes difficult to obtain a high reflectance. If it exceeds 25% by weight, mechanical properties such as strength of the film itself may be too low.
  • the incompatible polymer is preferably dispersed uniformly. Due to the uniform dispersion of the incompatible polymer, bubbles are uniformly formed inside the film, and the degree of whitening and thus the reflectance becomes uniform. In order to uniformly disperse the incompatible polymer, it is effective to add a low specific gravity agent as a dispersion aid.
  • a low specific gravity agent is a compound having the effect of reducing the specific gravity, and the effect is recognized for a specific compound.
  • polyalkylene glycols such as polyethylene glycol, methoxy polyethylene glycol, polytetramethylene glycol, polypropylene glycol, ethylenoxide Z propylenoxide copolymer, sodium dodecylbenzenesulfonate, sodium alkylsulfonate.
  • examples thereof include salts, glycerin monostearate, and tetrabutyl phospho-mparaaminobenzene sulfonate.
  • polyalkylene glycol particularly polyethylene glycol is particularly preferable.
  • a copolymer of polybutylene terephthalate and polytetramethylene glycol is also preferably used for improving the dispersibility of the incompatible polymer.
  • the addition amount of the low specific gravity agent is preferably 10% by weight or more and 25% by weight or less, with the total layer containing the incompatible polymer being 100% by weight. If the amount is less than 10% by weight, the effect of addition is reduced. If it exceeds 25% by weight, the original properties of the film base material may be impaired.
  • Such a low specific gravity agent can be added to the film base polymer in advance to prepare a master polymer (master chip).
  • the apparent specific gravity of the polyester film is lower than that of a normal polyester film. If a lower specific gravity agent is further added, the specific gravity is further lowered. In other words, a white and light film can be obtained.
  • the apparent specific gravity is preferably 0.5 or more and 1.2 or less. Furthermore, by making the apparent specific gravity 0.5 or more and 1.2 or less, it is possible to obtain higher reflectance, which is preferable. Good.
  • the apparent specific gravity is more preferably 0.5 or more and 1.0 or less, and particularly preferably 0.5 or more and 0.8 or less.
  • polymethylpentene having a specific gravity of 0.83 is used as the incompatible polymer as described above
  • polymethylpentene is used as a film. It should be contained in an amount of 5% to 25% by weight based on the polyester polymer of the base material.
  • an unstretched polyester film is prepared, and the unstretched polyester film can be achieved by stretching the stretch ratio in the machine direction and the transverse direction at 2.5 to 4.5 times.
  • the apparent specific gravity is in the range of 0.5 or more and 1.2 or less, when used as a reflective film, the brightness of the screen is remarkably excellent.
  • the glossiness of the white film according to the present invention is particularly limited if the difference ⁇ G in glossiness (60 °) between one surface and the other surface of the reflective film using the white film is greater than 80%.
  • the glossiness (60 °) of at least one side of the white film is preferably 90% or more. If the glossiness of one side of the white film is 90% or more, decrease the glossiness of the other side of the white film, or provide a resin layer on the other side of the white film to increase the glossiness of that side. By making it smaller, the AG of the reflective film can be easily made larger than 80%.
  • the glossiness of one side of the white film is more preferably 95% or more, then preferably 100% or more, then preferably 115% or more, and most preferably 120% or more.
  • the upper limit of the glossiness is not particularly limited, but is preferably less than 130%. If it exceeds 130%, the film surface friction coefficient becomes high, and it may be difficult to eliminate air at the time of scraping.
  • the white film according to the present invention can be formed in various layer configurations such as a single layer, two layers, and three layers. Above all, it consists of A layer, ZB layer, ZA layer, or A layer, ZB layer, and ZC layer, and the B layer is a layer containing the fine bubbles in order to achieve both high reflectivity and film formability. preferable.
  • additive agents can be added to each layer of the white film within the range without impairing the effects of the present invention.
  • additives include organic and Z or inorganic fine particles, fluorescent brighteners, heat stabilizers, ultraviolet absorbers, and acid-fastening agents. It has these functions due to the difference in glossiness with the surface of It is possible to distinguish which side of the white film is provided with the layer containing the additive.
  • Sarasako A layer ZB layer
  • the A layer equivalent to the film surface Inorganic polyester and Z or organic particles are added to the polyester, 0.5% by weight based on the total weight of each A layer It is preferable that it is the layer contained below.
  • the content is more preferably 0.1% by weight or less, particularly preferably 0.07% by weight or less.
  • inorganic particles and Z or organic particles are added to polyester, and each layer (inorganic fine particles and Z or organic particles is added to polyester).
  • the layer is preferably 0.5% by weight or less based on the total weight of the contained layer.
  • the content is more preferably 0.1% by weight or less, particularly preferably 0.07% by weight or less.
  • the white film according to the present invention preferably has a glossiness of at least 90% on at least one side, but the inorganic fine particles and Z contained in one outermost layer of the white film Alternatively, by setting the content of inorganic fine particles to 0.5% by weight, the glossiness of the surface can be made 90% or more. In addition, by increasing the content of inorganic fine particles and / or inorganic fine particles contained in the other outermost layer of the white film, the glossiness of the surface can be lowered, and one surface of the white film and the other surface can be reduced. It is possible to make a difference in glossiness with the surface. The content of inorganic fine particles and / or inorganic fine particles contained in each layer can be appropriately adjusted according to the desired difference in glossiness.
  • Polymethylpentene is added as an incompatible polymer, and polyethylene glycol, polybutylene terephthalate and a polytetramethylene glycol copolymer are added as a low specific gravity agent to polyethylene terephthalate. It is thoroughly mixed and dried and fed to Extruder B, which has been heated to a temperature of 270-300 ° C. If necessary, use a material containing inorganic additives such as SiO.
  • the polymer of Extruder B comes to the inner layer (B layer) and the polymer of Extruder A comes to both surface layers (A), so that A layer / B layer ZA layer 3
  • the layers may be laminated.
  • the molten sheet is closely cooled and solidified by electrostatic force on a drum cooled to a drum surface temperature of 10 to 60 ° C to obtain an unstretched film.
  • the unstretched film is led to a roll group heated to 80 to 120 ° C, stretched 2.0 to 5.0 times in the longitudinal direction, and cooled with a roll group of 20 to 50 ° C.
  • the film is stretched in the direction perpendicular to the longitudinal direction in an atmosphere heated to 90-140 ° C while being guided to a tenter while holding both ends of the longitudinally stretched film with clips.
  • the stretching ratio is 2.5 to 4.5 times in the longitudinal and lateral directions, respectively, and the area ratio (longitudinal stretching ratio X lateral stretching ratio) is preferably 9 to 16 times. If the area magnification is less than 9 times, the resulting white color of the film will be poor. If the area magnification exceeds 16 times, the film tends to be broken during stretching and the film forming property tends to be poor.
  • heat setting is performed at 150 to 230 ° C in a tenter, and after uniform cooling, the film is cooled to room temperature. And it winds up with a winder and obtains the white film which concerns on this invention.
  • a white resin film may be provided with a resin layer.
  • the glossiness of one side of the white film can be lowered, and ⁇ G of the reflective film can be easily increased to more than 80%.
  • the resin layer according to the present invention is not particularly limited, but a resin mainly composed of an organic component is preferable.
  • polyester resin, polyurethane resin, acrylic resin, methallyl resin, polyamide resin examples include polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyvinyl chloride resin resin, polystyrene resin, polyacetate resin resin, and fluorine-based resin.
  • coffins may be used alone or in the form of two or more types of copolymers or mixtures.
  • polyester resin, acrylic resin or methacrylic resin is preferably used in terms of heat resistance, particle dispersibility, coatability, and glossiness.
  • the white film of the present invention may be deteriorated by light emitted from a lamp such as a cold cathode tube during use, particularly ultraviolet light (for example, optical deterioration such as yellowing or decomposition deterioration that lowers the molecular weight). It is also preferable to use a resin layer containing an ultraviolet absorber and Z or a light stabilizer as the resin layer.
  • the resin constituting the resin layer containing the ultraviolet absorber is not particularly limited, but may be an acid.
  • Copolymers containing resin containing inorganic UV absorbers such as titanium fluoride and zinc oxide, resin containing organic UV absorbers such as benzotriazole and benzophenone, or benzotriazole and benzophenone reactive monomers Polymerized rosin can be used.
  • the resin constituting the resin layer containing the light stabilizer it is preferable to use an organic ultraviolet absorbing resin containing a resin copolymerized with a hindered amine (HALS) reactive monomer.
  • HALS hindered amine
  • the inorganic ultraviolet absorber zinc oxide, titanium oxide, cerium oxide, zirconium oxide and the like are generally used. Among these, at least one selected from the group consisting of zinc oxide, titanium oxide, and cerium oxide is preferable because it does not bleed out and is excellent in light resistance. Several types of UV absorbers may be used in combination as needed. Of these, zinc oxide is most preferable from the viewpoints of economy, ultraviolet absorption, and photocatalytic activity. As zinc oxide, FINEX-25LP, FINEX-50LP (manufactured by Sakai Chemical Industry Co., Ltd.) or the like can be used.
  • Examples of the organic ultraviolet absorber include a resin containing an organic ultraviolet absorber such as benzotriazole or benzophenone, a resin obtained by copolymerizing a benzotriazole-based or benzophenone-based reactive monomer, and further to these.
  • a resin obtained by copolymerizing a light stabilizer such as a hindered amine (HALS) -based reactive monomer can be used.
  • a thin layer of organic UV-absorbing resin containing benzotriazole-based and benzophenone-based reactive monomers, as well as those containing hindered amine (HALS) -based reactive monomers It is more preferable because the ultraviolet absorption effect is high.
  • HALS HYBRID registered trademark
  • acrylic monomer and UV absorber copolymer as an active ingredient
  • additives can be added to the resin layer within a range that does not impair the effects of the present invention.
  • Additives include, for example, organic and Z or inorganic fine particles, fluorescent brighteners, cross-linking agents, heat stabilizers, antioxidation stabilizers, organic lubricants, nucleating agents, couplings An agent or the like can be used.
  • the resin layer according to the present invention can be provided by a coating method.
  • the coating liquid can be applied by any method.
  • gravure coating, roll nut, spin nut, reno kusu: pi ot, no: pi ot, screen: pi ot, blade, n te, air knife coat, datebing, etc. can be used.
  • the coating liquid for forming the resin layer may be applied at the time of manufacturing the white film of the substrate (in-line coating), or may be applied on the white film after completion of crystal orientation (off-line coating).
  • the reflective film of the present invention has a heat shrinkage rate of 0.1% or more and 0.2% or less in the film longitudinal direction and film width direction after heat treatment at 90 ° C for 30 minutes as a reflective film. Is preferred. Preferably it is 0.05-5.15% or less. If the thermal shrinkage in the film longitudinal direction or film width direction is out of the range of 0.1% or more and 0.2% or less, the film becomes squeezed when it reaches a high temperature, and the brightness of the liquid crystal knock light Unevenness is likely to occur. In particular, in the case of a reflective film for use in a reverse prism, when a prism-shaped light guide plate comes into contact with a mirror-like reflective surface, it tends to be noticeable as a screen unevenness on the liquid crystal panel.
  • the heat shrinkage rate in the longitudinal direction of the film after the heat treatment at 90 ° C for 30 minutes is a value measured by the following procedure. First, a film sample of a certain size is prepared, and a certain length (L) is measured in the longitudinal direction (extrusion direction during production) at room temperature. Sample 9
  • the obtained value is defined as the heat shrinkage rate in the longitudinal direction of the film.
  • a negative value indicates that the film is stretched.
  • the heat shrinkage in the width direction of the film after heat treatment at 90 ° C for 30 minutes is the same as the longitudinal direction of the film in the width direction of the film (perpendicular to the extrusion direction during production). This is the measured value.
  • the reflective film of the present invention preferably has an average reflectance of 85% or more at a wavelength of 400 to 700 nm measured from the surface provided with the resin layer. More preferably 87% or more, especially Preferably it is 90% or more. If the average reflectance is less than 85%, the brightness may be insufficient depending on the liquid crystal display used. In addition, when a resin layer containing an ultraviolet absorber and Z or a light stabilizer is provided on both sides of the white film, the average reflectivity measured for any resin layer force should be 85% or more. That's fine.
  • the reflective film of the present invention can be preferably used in a liquid crystal backlight of a direct type for use in liquid crystal TVs and large monitors.
  • a reflective film is installed near the cold cathode tube in the direct-type liquid crystal knock light.
  • the surface of the reflecting film provided with the resin layer preferably, the resin layer containing the ultraviolet absorber and Z or the light stabilizer
  • the white film of the base material may turn yellow due to ultraviolet rays. Therefore, when assembling the knocklight, it is necessary to distinguish between the surface of the reflective film provided with the resin layer and the opposite surface.
  • the reflective film of the present invention it is easy to distinguish between the surface on which the resin layer is provided and the surface on the opposite side, the work efficiency in the assembly process of the knock light is improved, and the productivity is also improved.
  • the reflective film of the present invention can be preferably used for a lamp reflector of a liquid crystal backlight.
  • the lamp refractor is formed by bonding a stainless steel plate and a reflective film, and press-molding them in a curved shape so that the reflective film is on the inside. Then, the lamp reflector is assembled into a knocklight so as to cover the cold cathode tube as shown in FIG. As with the direct backlight, the lamp reflector is also provided with a reflective film near the cold cathode tube.
  • the surface of the reflective film provided with the resin layer (preferably a resin layer containing an ultraviolet absorber and Z or a light stabilizer) is directed to the cold cathode tube side so that the stainless steel plate and the reflective film are provided. Otherwise, the white film of the base material may turn yellow due to the ultraviolet rays generated by the cold cathode tube. Therefore, when bonding, it is necessary to distinguish the surface on which the resin layer is provided and the surface on the opposite side. In the surface light source reflecting member film of the present invention, it is easy to distinguish between the surface provided with the resin layer and the surface on the opposite side, the work efficiency in the bonding process is improved, and the productivity is also improved. .
  • the reflective film of the present invention can be suitably used for a reverse prism type liquid crystal backlight.
  • the knocklight housing and the reflective film may come into contact with each other and be scratched.
  • edge-light type backlight for light weight
  • scratches on the reflective film can be seen through this cavity. Knocklights with visible scratches will degrade the quality of the finished product, resulting in a decrease in yield. If the glossiness of the reflective film is low, scratches on the surface will be inconspicuous.
  • a reflective film with a high glossiness is required to increase the brightness, especially in the reverse prism type liquid crystal knocklight.
  • the reverse prism type liquid crystal backlight using the reflective film of the present invention can improve the yield without impairing the quality of the finished knocklight product, and can also increase the brightness.
  • the average reflectance of the surface of the reflective film on which the resin layer is provided is measured by the following procedure. Attach an integrating sphere to a Hitachi High-Technologies spectrophotometer (U-3310), and measure the reflectivity from 400 to 700 nm when the standard white plate (acid aluminum) is 100%. Read the reflectance at 5nm intervals from the obtained chart, calculate the average value of them, and use it as the average reflectance. Three samples were measured for each reflective film, and the average value was taken as the average reflectance of the reflective film. If the reflective film is not provided with a resin layer, the average reflectivity of the surface regarded as the “surface provided with the resin layer” in the measurement of “(3) Glossiness (60 °;)”. Measure.
  • a negative value indicates that the film is stretched.
  • a 10 mm wide (film longitudinal direction) x 230 mm long (film width direction) sample was cut out from the reflective film and measured in the same manner as the method for measuring the thermal shrinkage in the longitudinal direction.
  • the glossiness (60 °) of both the surface of the reflective film provided with the resin layer and the opposite surface is measured by the following procedure. Using a digital variable angle gloss meter (UGV-4D) manufactured by Suga Test Instruments Co., Ltd., the glossiness was measured according to JIS K7105 (1981 version) with the incident angle and light receiving angle adjusted to 60 °. Three samples were measured for each reflection film, and the average value was defined as the glossiness (60 °) of the reflection film. In addition, the oil film layer is provided on the reflective film! In the case of /, NA V, the glossiness is small! /, And the side of the surface (if the glossiness is the same on both sides, one of the sides) is regarded as the “surface with the resin layer”.
  • UUV-4D digital variable angle gloss meter
  • the reflective film was placed in an ultraviolet degradation acceleration tester iSuper UV Tester SUV-W131 (manufactured by Iwasaki Electric Co., Ltd.), and a forced ultraviolet irradiation test was performed under the following conditions.
  • iSuper UV Tester SUV-W131 manufactured by Iwasaki Electric Co., Ltd.
  • the surface of the reflective film provided with a resin layer was rubbed 3 times at a stroke width of 10 cm and a speed of 30 mmZsec by applying a load of 100 g of # 0000 steel wool. Arbitrarily selected 10
  • the surface provided with the rosin layer was visually observed by a name judge. If all 10 people did not see any scratches, it was rated as ⁇ . If the reflective film is not provided with a resin layer, the surface considered as the “surface provided with the resin layer” was scratched in the measurement of “(3) Glossiness (60 °;)”. The surface was observed. Each reflective film was evaluated with one sample.
  • a polyethylene terephthalate chip (F20S manufactured by Toray Industries, Inc.) and a master chip containing a polyethylene glycol having a molecular weight of 4000, a copolymer of polybutylene terephthalate and polytetramethylene glycol, added during the polymerization of polyethylene terephthalate are 180 °. Vacuum dried at C for 3 hours.
  • this sheet was cooled and solidified with a cooling drum having a surface temperature of 25 ° C to obtain an unstretched film.
  • the unstretched film was guided to a roll group heated to 85 to 98 ° C, stretched 3.4 times in the longitudinal direction of the film, and cooled with a roll group at 25 ° C.
  • the film stretched in the longitudinal direction is guided to the tenter while holding both ends of the film with clips, and in the atmosphere heated to 130 ° C in the film width direction (direction perpendicular to the film longitudinal direction) 3.6 It was stretched by a factor of 2. After that, heat setting was performed at 230 ° C in a tenter, and after uniform cooling, it was cooled to room temperature.
  • a coating solution prepared by adding 8 g with stirring was prepared. This coating solution was applied to one side of a white film so that the thickness after drying was 3 m, a resin layer was provided, and the coating was dried. The coating solution was dried at a temperature of 130 ° C for 1 minute. Thus, a reflective film was obtained. The glossiness (60 °) of the surface of the reflective film provided with the resin layer was 25%.
  • a white film was obtained in the same manner as in Example 1 except that the amount of the master chip (silicon dioxide content 2% by weight) mixed in the A layer was 2 parts by weight.
  • the resulting film had a glossiness (60 °) of 107%.
  • a white film was obtained in the same manner as in Example 1 except that the amount of the master chip (silicon dioxide content 2% by weight) mixed in the A layer was 3.5 parts by weight. Glossiness of the obtained film
  • this sheet was stretched under the same conditions as in Example 1 to obtain a white film.
  • the glossiness (60 °) of the white paper film obtained was 121% on the A layer side and 95% on the C layer side.
  • a reflective film was obtained by providing a resin layer on the layer surface. The glossiness (60 °) of the surface of the reflective film provided with the resin layer was 14%.
  • a reflective film was obtained in the same manner as in Example 1 except that the resin layer was not provided.
  • Example 1 As described in Example 1 on one side of a white film made of 188 ⁇ m porous biaxially stretched polyethylene terephthalate (Lumirror (registered trademark) E60L, Toray Industries, Inc., glossiness (60 °): 30%)) A resin film was provided to obtain a reflective film. The luminous intensity (60 °) of the surface of the reflective film provided with the resin layer was 25%.
  • Examples 1 to 4 it was possible to easily distinguish the surface provided with the resin layer having a gloss difference of more than 80% and the surface on the opposite side. Furthermore, in Examples 1 to 4, the glossiness of the surface with a low glossiness (surface with the resin layer) was 25% or less, and the scratches on the surface were difficult to see.
  • Comparative Examples 1 to 4 the difference in glossiness was 80% or less, and it was difficult to distinguish the surface on which the resin layer was provided and the surface on the opposite side. In Comparative Examples 1 and 2, it was confirmed that the surface having a low glossiness (the surface provided with the resin layer) had a glossiness of more than 50%, and the surface was scratched.
  • the film for a surface light source reflecting member of the present invention can be suitably used for a liquid crystal knocklight.
  • it can be suitably used for a direct type liquid crystal backlight, a reverse prism type liquid crystal backlight, and a lamp reflector for a liquid crystal backlight.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Optical Elements Other Than Lenses (AREA)
  • Laminated Bodies (AREA)
  • Liquid Crystal (AREA)

Abstract

La présente invention concerne un film destiné à un élément réfléchissant d'une source lumineuse superficielle qui se compose d'un film blanc et qui présente une différence de brillance (60°) Δ G entre une surface et la surface opposée qui satisfait la relation Δ G>80. l'invention porte donc sur un film destiné à un élément réfléchissant de source lumineuse superficielle qui facilite la discrimination visuelle entre une surface dotée d'une couche fonctionnalisée et sa surface opposée, ce qui permet alors d'accroître la productivité lors de la production d'un rétroéclairage à cristaux liquides.
PCT/JP2007/051343 2006-02-03 2007-01-29 Film destine a un element reflechissant de source lumineuse superficielle WO2007088797A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
CN2007800034434A CN101375185B (zh) 2006-02-03 2007-01-29 面光源反射部件用膜
JP2007509754A JP5040647B2 (ja) 2006-02-03 2007-01-29 面光源反射部材用フィルム
KR1020087016211A KR101331888B1 (ko) 2006-02-03 2007-01-29 면광원 반사 부재용 필름

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JP2006026635 2006-02-03
JP2006-026635 2006-02-03

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012132895A1 (fr) * 2011-03-29 2012-10-04 東レ株式会社 Film de réflexion coloré en blanc pour un rétroéclairage du type à éclairage par le bord, et rétroéclairage d'affichage à cristaux liquides utilisant ce dernier
JP2012200921A (ja) * 2011-03-24 2012-10-22 Toray Ind Inc 反射板用白色積層ポリエステルフィルムおよびバックライト装置
JP2014510387A (ja) * 2011-04-04 2014-04-24 エルジー イノテック カンパニー リミテッド 照明装置
JP2019128467A (ja) * 2018-01-25 2019-08-01 コニカミノルタ株式会社 光学フィルムおよびその製造方法
US11994768B2 (en) 2011-04-04 2024-05-28 Lg Innotek Co., Ltd. Lighting apparatus

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Publication number Priority date Publication date Assignee Title
WO2009075227A1 (fr) * 2007-12-11 2009-06-18 Toray Industries, Inc. Film en couches
CN107111014B (zh) * 2015-01-05 2020-05-19 帝人薄膜解决方案有限公司 直下型面光源用白色反射膜及使用该膜的直下型面光源

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JPH05330247A (ja) * 1992-06-03 1993-12-14 New Oji Paper Co Ltd 染料熱転写受容シート
JP2004276577A (ja) * 2003-03-12 2004-10-07 Toray Saehan Inc 微細気孔含有ポリエステルフィルム
JP2005125700A (ja) * 2003-10-27 2005-05-19 Teijin Dupont Films Japan Ltd 白色ポリエステルフィルム

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JPH111264A (ja) * 1997-06-16 1999-01-06 Toray Monofilament Co Ltd 結束用資材
JP4345305B2 (ja) 2003-01-09 2009-10-14 東レ株式会社 光反射フィルムおよびそれを用いた面光源
JP4525055B2 (ja) * 2003-11-18 2010-08-18 東レ株式会社 光反射フィルムおよびそれを用いた面光源
EP1759834A4 (fr) * 2004-06-17 2007-06-06 Teijin Dupont Films Japan Ltd Film stratifié pour plaque de réflexion

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JPH05330247A (ja) * 1992-06-03 1993-12-14 New Oji Paper Co Ltd 染料熱転写受容シート
JP2004276577A (ja) * 2003-03-12 2004-10-07 Toray Saehan Inc 微細気孔含有ポリエステルフィルム
JP2005125700A (ja) * 2003-10-27 2005-05-19 Teijin Dupont Films Japan Ltd 白色ポリエステルフィルム

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012200921A (ja) * 2011-03-24 2012-10-22 Toray Ind Inc 反射板用白色積層ポリエステルフィルムおよびバックライト装置
US9625120B2 (en) 2011-03-29 2017-04-18 Toray Industries, Inc. White reflective film for edge-light type backlight, and liquid crystal display backlight using same
JP5218931B2 (ja) * 2011-03-29 2013-06-26 東レ株式会社 エッジライト型バックライト用白色反射フィルム及びそれを用いた液晶ディスプレイ用バックライト
KR101375917B1 (ko) 2011-03-29 2014-03-18 도레이 카부시키가이샤 엣지 라이트형 백 라이트용 백색 반사 필름 및 그것을 이용한 액정 디스플레이용 백 라이트
WO2012132895A1 (fr) * 2011-03-29 2012-10-04 東レ株式会社 Film de réflexion coloré en blanc pour un rétroéclairage du type à éclairage par le bord, et rétroéclairage d'affichage à cristaux liquides utilisant ce dernier
US9982849B2 (en) 2011-04-04 2018-05-29 Lg Innotek Co., Ltd. Lighting apparatus
JP2014510387A (ja) * 2011-04-04 2014-04-24 エルジー イノテック カンパニー リミテッド 照明装置
US10139054B2 (en) 2011-04-04 2018-11-27 Lg Innotek Co., Ltd. Lighting apparatus
US10877313B2 (en) 2011-04-04 2020-12-29 Lg Innotek Co., Ltd. Lighting apparatus
US11243428B2 (en) 2011-04-04 2022-02-08 Lg Innotek Co., Ltd. Lighting apparatus
US11586069B2 (en) 2011-04-04 2023-02-21 Lg Innotek Co., Ltd. Lighting apparatus
US11754877B2 (en) 2011-04-04 2023-09-12 Lg Innotek Co., Ltd. Lighting apparatus
US11994768B2 (en) 2011-04-04 2024-05-28 Lg Innotek Co., Ltd. Lighting apparatus
JP2019128467A (ja) * 2018-01-25 2019-08-01 コニカミノルタ株式会社 光学フィルムおよびその製造方法
JP7308592B2 (ja) 2018-01-25 2023-07-14 コニカミノルタ株式会社 光学フィルムおよびその製造方法

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KR20080091128A (ko) 2008-10-09
CN101375185A (zh) 2009-02-25
TW200741256A (en) 2007-11-01
JP5040647B2 (ja) 2012-10-03
CN101375185B (zh) 2011-07-06
KR101331888B1 (ko) 2013-11-22
JPWO2007088797A1 (ja) 2009-06-25
TWI425251B (zh) 2014-02-01

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