WO2011118305A1 - Film de polyester blanc, plaque réfléchissant la lumière le comprenant, et rétro-éclairage d'affichage à cristaux liquides le comprenant - Google Patents

Film de polyester blanc, plaque réfléchissant la lumière le comprenant, et rétro-éclairage d'affichage à cristaux liquides le comprenant Download PDF

Info

Publication number
WO2011118305A1
WO2011118305A1 PCT/JP2011/053633 JP2011053633W WO2011118305A1 WO 2011118305 A1 WO2011118305 A1 WO 2011118305A1 JP 2011053633 W JP2011053633 W JP 2011053633W WO 2011118305 A1 WO2011118305 A1 WO 2011118305A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
polyester film
white polyester
light
film
Prior art date
Application number
PCT/JP2011/053633
Other languages
English (en)
Japanese (ja)
Inventor
舩冨剛志
長谷川正大
奥田昌寛
Original Assignee
東レ株式会社
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 東レ株式会社 filed Critical 東レ株式会社
Priority to JP2011522311A priority Critical patent/JP5045851B2/ja
Priority to KR1020127022727A priority patent/KR101772015B1/ko
Priority to CN201180010943.7A priority patent/CN102782532B/zh
Publication of WO2011118305A1 publication Critical patent/WO2011118305A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0205—Diffusing elements; Afocal elements characterised by the diffusing properties
    • G02B5/0236—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place within the volume of the element
    • G02B5/0242—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place within the volume of the element by means of dispersed particles
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0273—Diffusing elements; Afocal elements characterized by the use
    • G02B5/0284—Diffusing elements; Afocal elements characterized by the use used in reflection
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/08—Mirrors
    • 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
    • G02B6/0053—Prismatic sheet or layer; Brightness enhancement element, sheet or layer
    • 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
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133605—Direct backlight including specially adapted reflectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/042—PV modules or arrays of single PV cells
    • H01L31/048—Encapsulation of modules
    • H01L31/049—Protective back sheets
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy

Definitions

  • the present invention relates to a white polyester film suitable for use as a light reflecting plate, a light reflecting plate using the same, and a backlight for a liquid crystal display.
  • a backlight method in which light is applied from the back of the display and a light reflecting plate are widely used because of a thin and uniform illumination.
  • a light reflector on the back of the screen, but this reflector is required to be thin and have high light reflectivity.
  • a white film or the like that is whitened by containing fine bubbles inside and reflecting light at the bubble interface is mainly used.
  • the light reflected by the reflector is diffused, and the light other than the light that has directivity directly is reflected by the prism, and is repeatedly reflected between the reflector and finally the liquid crystal cell with enhanced light directivity. Sent to. In this case, if the reflection efficiency of the reflector is low, or if there is a factor that causes light leakage or attenuation in the system, light loss will occur during repeated reflections and the energy efficiency will deteriorate, reducing the brightness of the screen. Or the economy is reduced.
  • Such a white polyester film is also used for a back sheet of a solar cell.
  • Patent Document 1 describes that a light reflecting plate is used as one member constituting a light source of a liquid crystal display.
  • Patent Document 2 describes that a white film whitened by containing fine bubbles inside the film and reflecting light at the bubble interface is used as the light reflecting plate.
  • Patent Documents 3 and 4 describe a white film in which an ultraviolet absorbing layer is laminated in order to prevent yellow discoloration of the film due to ultraviolet rays emitted from a cold cathode tube.
  • Patent Document 5 discloses a method of providing a light concealing layer on a film surface opposite to a light source in order to improve luminance in an edge light system.
  • Patent Document 6 discloses a method of controlling the light diffusibility by selecting the refractive index difference between the spherical particles and the binder and improving the front luminance by the light diffusion sheet.
  • Patent Document 7 discloses a method of improving luminance unevenness in a backlight by controlling the diffusibility of a film surface on the light source side in a reflection sheet in a direct type backlight.
  • Patent Document 1 The reflector described in Patent Document 1 was not sufficiently thin and highly reflective.
  • an ultraviolet absorbing layer is provided, or in a method in which the ultraviolet absorbing layer contains a trace amount of a fluorescent brightening agent, the absorbed ultraviolet energy is converted into heat, or the reflective film
  • the brightness of the screen is reduced because only a small amount of light that contributes to color adjustment is converted.
  • the reflectors described in Patent Documents 5 and 6 have a problem that the color change due to ultraviolet rays radiated from the cold cathode fluorescent lamp is large, and the use efficiency of light energy as a backlight is deteriorated and the luminance of the screen is lowered.
  • Patent Document 7 contains porous and hollow particles and particles with non-uniform shapes together with a small amount of fluorescent brightening agent, even with a small amount of light that contributes to color adjustment, depending on the contained particles There has been a problem that light is attenuated by refraction, reflection, scattering, and the like, and the luminance is not improved.
  • the white film In the reflection plate, it is necessary to prevent the white film from being deteriorated by the ultraviolet light (hereinafter referred to as UV) emitted from the lamp light source or with the white film while improving the reflection efficiency of the white film.
  • UV ultraviolet light
  • a conventionally known method for example, as disclosed in the aforementioned Patent Documents 3 and 4, a method of reducing the amount of ultraviolet rays reaching the polyester resin by thickly applying a layer containing a UV absorber to a white film was there.
  • the layer containing the UV absorber is processed by post-processing, there is a problem in economic efficiency and lead time.
  • the film used as the reflector is desirably thin from the viewpoints of miniaturization and weight reduction and processability.
  • the reflection efficiency is lowered, so that the leakage needs to be suppressed as much as possible.
  • the present invention eliminates the disadvantages of these conventional techniques, has high brightness, has little color change due to ultraviolet rays from the lamp or the sun, can prevent light leakage to the back surface, and further requires no post-processing, and is a white polyester film
  • the purpose is to provide.
  • an object of the present invention is a white polyester film having at least two layers of an A layer composed of polyester and a B layer composed of polyester, wherein the B layer has bubbles, and the A layer is rutile.
  • the total thickness of the white polyester film is 100 ⁇ m or more and 500 ⁇ m or less
  • the thickness of the A layer is 2 ⁇ m or more and 16 ⁇ m or less Is done.
  • the object of the present invention is achieved by a light reflector using the above white polyester film.
  • the object of the present invention is achieved by a backlight for a liquid crystal display in which the white polyester film is arranged with the layer A side facing the light source.
  • the A layer contains 2 to 6% by mass of the rutile-type titanium oxide with respect to the total mass of the A layer, and the barium sulfate to the total mass of the A layer.
  • the rutile titanium oxide preferably has a number average particle size of 0.1 ⁇ m or more and 1.0 ⁇ m or less.
  • the barium sulfate preferably has a number average particle diameter of 0.5 ⁇ m to 3.0 ⁇ m.
  • the number average particle diameter of the silicon dioxide is preferably 2.0 ⁇ m or more and 5.0 ⁇ m or less.
  • the layer B preferably contains a polymer incompatible with polyester, or a polymer incompatible with polyester and inorganic particles dispersed therein.
  • the white polyester film of the present invention is obtained by irradiating the layer A with ultraviolet rays under the conditions of illuminance: 100 mW / cm 2 , temperature: 60 ° C., relative humidity: 50% RH, and irradiation time: 48 hours. Yellowish change amount after UV irradiation: ⁇ b value is preferably less than 5.
  • a white polyester film that has high brightness, little color change due to ultraviolet rays from a lamp or the sun, can prevent light leakage to the back surface, and does not require post-processing.
  • the white polyester film of the present invention is suitably used for a large direct light type liquid crystal display used for televisions and the like, and a small sidelight type liquid crystal display used for notebook computers, mobile phones and the like. Moreover, it can be used as a back sheet for solar cells, and contributes to the efficiency of conversion from sunlight to electricity, and can impart resistance to ultraviolet rays from sunlight.
  • the white polyester film of the present invention is a white polyester film having at least a layer A composed of polyester and a layer B composed of polyester, wherein the layer B has bubbles, and the layer A is a rutile titanium oxide, Three types of inorganic particles of barium sulfate and silicon dioxide are contained, the total thickness of the white polyester film is 100 ⁇ m or more and 500 ⁇ m or less, and the thickness of the A layer is 2 ⁇ m or more and 16 ⁇ m or less.
  • the A layer is a layer in which inorganic particles are contained in polyester, and has a role of scattering the light and protecting the film from ultraviolet rays. It also has a role of preventing light leakage to the back surface and a role of a support layer for stabilizing the film formation.
  • the light scattering property of the A layer can be adjusted mainly by controlling the surface roughness.
  • a method of adding particles having different refractive indexes to a polyester resin can be mentioned.
  • the thickness of the A layer is 2 ⁇ m or more and 16 ⁇ m or less.
  • the B layer is a layer having bubbles. Therefore, if the thickness of the A layer is 2 ⁇ m or more and 16 ⁇ m or less, moderate irregularities are formed on the surface of the A layer due to the bubbles, The scattering property is extremely good.
  • inorganic particles having an ultraviolet absorbing ability and a light stabilizer are included, a film having good resistance to ultraviolet rays and high brightness can be obtained.
  • the A layer is disposed on the light source side, the A layer is gradually decomposed by the energy of ultraviolet rays.
  • a preferable range of the thickness of the A layer is 2 ⁇ m or more and 8 ⁇ m or less, and more preferably 2 ⁇ m or more and 6 ⁇ m or less.
  • the thickness of the A layer that is directed to the light source side at least at the outermost layer is 2 ⁇ m or more and 16 ⁇ m or less. Need to be. As described above, when the thickness of the A layer is less than 2 ⁇ m, the photolysis of the polyester has an adverse effect on the luminance, and the high luminance cannot be maintained. On the other hand, when the thickness of the A layer exceeds 16 ⁇ m, the loss of light energy in the A layer cannot be ignored, and the light does not sufficiently reach the voids in the B layer.
  • the total thickness of the white polyester film of the present invention is 100 ⁇ m or more and 500 ⁇ m or less. If the total thickness of the white polyester film is less than 100 ⁇ m, the reflectance is insufficient.
  • the upper limit is not particularly limited, but if the thickness exceeds 500 ⁇ m, no increase in reflectance can be expected even if the thickness is increased beyond this, and therefore the upper limit is usually 500 ⁇ m.
  • the surface of the layer A is arranged toward the light source side, so that UV resistance, reduction in luminance unevenness, high reflectance, scratches on the light guide plate, and suppression of occurrence of uneven contact screen are suppressed.
  • the layer structure may be a two-layer structure of A layer / B layer, a three-layer structure of A layer / B layer / A layer, or a structure of four or more layers, but it is easy on film formation. Considering this, a three-layer structure is preferable.
  • the resin constituting the A layer and the B layer is polyester.
  • polyethylene terephthalate and polyethylene naphthalate are preferable.
  • additives such as an antioxidant and an antistatic agent may be added to the polyester.
  • the B layer is whitened by containing fine bubbles inside the film.
  • the formation of fine bubbles is caused by finely dispersing a polymer incompatible with polyester or a polymer incompatible with polyester and inorganic particles in a film base material such as polyester and stretching it (for example, biaxially). This can be achieved by stretching.
  • the layer A contains rutile type titanium oxide.
  • rutile type titanium oxide When rutile type titanium oxide is used, there is less yellowing after irradiating the polyester film with light for a longer time than when anatase type titanium oxide is used, and the change in color difference can be suppressed.
  • this rutile-type titanium oxide is used after being treated with a fatty acid such as stearic acid or a derivative thereof, the dispersibility can be improved and the glossiness of the film can be further improved.
  • the number average particle diameter (diameter) of rutile type titanium oxide is preferably 0.1 ⁇ m or more and 1.0 ⁇ m or less. When the number average particle diameter of rutile type titanium oxide is within this range, aggregation is difficult to occur, uniform dispersibility is good, and light resistance is excellent, while film stretchability is also good, productivity is high, and light resistance is excellent. .
  • the addition amount of rutile type titanium oxide is preferably 2% by mass or more and 6% by mass or less with respect to the mass of the entire A layer.
  • the addition amount of rutile-type titanium oxide is within this range, the stretchability of the film is good, and even after the polyester film is irradiated with light for a long time, there is little yellowing and the change in color difference can be suppressed. Further, it is difficult to cause a reduction in reflection performance and luminance unevenness, and the screen luminance can be improved.
  • the white polyester film of the present invention is complementary because of reduced reflection performance and uneven brightness. It is necessary to combine barium sulfate. Thus, when barium sulfate is complementarily combined, a favorable reflectance can be obtained and luminance unevenness can be reduced. Since barium sulfate is incompatible with polyester, many fine bubbles can exist even in the A layer, and there is little yellowing after irradiating the polyester film with light for a long time, suppressing the change in color difference. it can.
  • the number average particle diameter (diameter) of barium sulfate is preferably 0.5 ⁇ m or more and 3.0 ⁇ m or less.
  • the addition amount of barium sulfate is preferably 16% by mass or more and 24% by mass or less with respect to the total mass of the A layer.
  • the reflectance does not decrease, the yellowing after irradiating the polyester film with light for a long time is small, and it is easy to suppress the change in color difference. The stretchability is not impaired and the productivity is good.
  • the white film surface that is, the surface of the layer A has a certain degree of roughness, and is easily available for the purpose of reducing the adhesion between the screen and the white film.
  • the number average particle diameter (diameter) of silicon dioxide is preferably 2.0 ⁇ m or more and 5.0 ⁇ m or less.
  • the direct reflection component does not increase excessively, and the difference in brightness (brightness unevenness) according to the interval between the illumination light sources hardly occurs, so that the brightness of the liquid crystal screen can be kept uniform.
  • particles that have become too coarse will not fall off, and the light guide plate will not be scratched.
  • the direct type since there is a cold cathode tube between the light guide plate and the reflection plate, the light guide plate and the reflection plate are not in direct contact with each other, and there is no worry about the occurrence of scratches on the light guide plate and uneven contact screen.
  • the content of silicon dioxide is preferably 0.5% by mass or more and 3% by mass or less with respect to the mass of the entire A layer.
  • the content of silicon dioxide is within this range, the surface roughness becomes too low and luminance unevenness does not occur, and the brightness of the liquid crystal screen can be made uniform.
  • the stretchability of the film is not impaired and the productivity is good.
  • the total content of the three types of inorganic particles of rutile titanium oxide, barium sulfate and silicon dioxide per 100% by mass of the A layer is preferably 10% by mass or more and 50% by mass or less. More preferably, they are 12 mass% or more and 40 mass% or less, More preferably, they are 15 mass% or more and 30 mass% or less. When the total content of the inorganic particles is within this range, necessary UV resistance and reflectance can be easily obtained, while cutting during film formation hardly occurs.
  • the white polyester film of the present invention has a configuration in which a plurality of A layers are present such as A layer / B layer / A layer
  • the content of the aforementioned rutile titanium oxide, barium sulfate, and silicon dioxide is preferable.
  • the preferable range and the preferred range of the number average particle diameter apply to the A layer directed to the light source side at least in the outermost layer.
  • the white polyester film of the present invention has a yellowness change amount ( ⁇ b value) after irradiation with ultraviolet rays on layer A for illuminance: 100 mW / cm 2 , temperature: 60 ° C., relative humidity: 50% RH, irradiation time: 48 hours. Preferably it is less than 5.
  • the ⁇ b value is more preferably less than 4 and even more preferably less than 3.
  • the lower limit is not particularly limited and is theoretically zero.
  • the white polyester film of the present invention can easily achieve the above ⁇ b value by using three kinds of inorganic particles of rutile type titanium oxide, barium sulfate and silicon dioxide in combination. Even so, it is useful in that the color change can be reduced. Moreover, there is almost no loss of luminance as a reflector.
  • Cyclic olefin as an incompatible polymer polyethylene glycol, polybutylene terephthalate and polytetramethylene glycol copolymer as a low specific gravity agent are mixed with polyethylene terephthalate, thoroughly mixed and dried, and a temperature of 270 to 300 ° C.
  • barium sulfate and silicon dioxide is supplied to the extruder A by a conventional method, and the polymer of the extruder B layer is formed on both surface layers in the T-die three-layer die. A three-layer structure of A layer / B layer / A layer was obtained.
  • the melted sheet is closely cooled and solidified by electrostatic force on a drum cooled to a drum surface temperature of 10 to 60 ° C., and the unstretched film is led to a group of rolls heated to 80 to 120 ° C. in the longitudinal direction.
  • the film is stretched 2.0 to 5.0 times in length and cooled with a roll group of 20 to 50 ° C. Subsequently, the film is stretched in the direction perpendicular to the longitudinal direction in an atmosphere heated to 90 to 140 ° C. while being guided to a tenter while holding both ends of the film that has been stretched with clips.
  • the stretching ratio is 2.5 to 4.5 times in the longitudinal and lateral directions, and the area ratio (longitudinal stretching ratio ⁇ lateral stretching ratio) is preferably 9 to 16 times.
  • the white polyester film of the present invention preferably has an average reflectance of 90% or more, more preferably 95% or more, and particularly preferably 97% or more at a wavelength of 400 to 700 nm as measured from the layer A surface.
  • the average reflectance is less than 90%, the luminance may be insufficient depending on the applied liquid crystal display.
  • the white polyester film of the present invention thus obtained can improve the luminance of the liquid crystal backlight, and since the reflectance does not decrease much even when used for a long time, the edge light and the direct type light for liquid crystal screens. It can be conveniently used as a reflector for a surface light source and a reflector.
  • the white polyester film for reflecting a liquid crystal display according to the present invention thus obtained has a high reflectance because fine bubbles are formed inside the film, and is used as a reflector for liquid crystal displays of side light type and direct light type. In this case, high brightness can be obtained.
  • the physical property value evaluation method and the effect evaluation method of the present invention are as follows. (1) Film thickness / layer thickness The film thickness was measured according to JIS C2151-2006.
  • the film was cut in the thickness direction using a microtome to obtain a section sample.
  • the section of the slice sample was imaged at a magnification of 3,000 times using a Hitachi Field Emission Scanning Electron Microscope (FE-SEM) S-800, and the thickness of each layer was measured and the thickness ratio was calculated by measuring the thickness of the laminate. .
  • FE-SEM Hitachi Field Emission Scanning Electron Microscope
  • An integrating sphere is attached to a spectrophotometer (U-3310) manufactured by Hitachi High-Technologies, and the reflectance when the standard white plate (aluminum oxide) is 100% is measured over a wavelength range of 400 to 700 nm. The reflectance was read from the obtained chart at intervals of 5 nm to obtain spectral reflectance.
  • the reflecting plate laminated in the backlight of 181BLM07 manufactured by NEC Corporation
  • the backlight is formed by stacking elements of the light reflecting white polyester film 1, the cold cathode tube 2, the milky white plate 3, the diffusion plate 4, the prism sheet 5, and the polarizing prism sheet 6 in order from the bottom to the top in FIG. Composed.
  • the liquid crystal screen was photographed with a CCD camera 7 (DXC-390 manufactured by SONY), and an image was captured with an eye scale 8 manufactured by an image analyzer Eye System. Thereafter, the luminance level of the photographed image was controlled to 30,000 steps and automatically detected, and converted into luminance to obtain the relative luminance value (%).
  • Relative luminance was determined by the following standard using # 250E6SL manufactured by Toray Industries, Inc. as a reference sample (100%).
  • luminance unevenness (%) was obtained by the following equation.
  • Unevenness of luminance (%) (maximum relative luminance value ⁇ minimum relative luminance value) / average relative luminance value ⁇ 100
  • the brightness unevenness was determined according to the following criteria using # 250E6SL manufactured by Toray Industries, Inc. as a reference sample (100%).
  • the number average diameter when each particle was converted to a perfect circle was calculated and used as the average particle diameter of the inorganic particles.
  • Yellowness (b value), ⁇ b value Using an SM color computer (manufactured by Suga Test Instruments Co., Ltd.), a b value representing yellowness was determined by a reflection measurement method using a C / 2 ° light source.
  • Light resistance (yellowishness change: ⁇ b value) Light resistance was evaluated by irradiating the sample with ultraviolet rays using an iSuper UV tester (model number: SUV-W131) manufactured by Iwasaki Electric Co., Ltd. and measuring the color tone b value before and after the irradiation.
  • the change in b value before and after UV irradiation was defined as ⁇ b. That is, as shown in the following equation, the ⁇ b value is the difference between the yellowness b 2 after UV irradiation and the initial yellowness b 1 .
  • ⁇ b value yellowness b 2 after UV irradiation ⁇ initial yellowness b 1
  • the ultraviolet irradiation conditions were as follows.
  • Illuminance 100 mW / cm 2 , temperature: 60 ° C., relative humidity: 50% RH, irradiation time: 48 hours
  • Light resistance was graded according to the following criteria.
  • the film can be stably formed for 24 hours or more.
  • the film can be stably formed for 12 hours or more and less than 24 hours.
  • the presence or absence of scratches was visually confirmed, and the light guide plate scratches were determined according to the following criteria.
  • Example 1 Polyethylene glycol having a molecular weight of 4,000 and having a color tone of polyethylene terephthalate after polymerization (JIS K7105-1981, measured by stimulus value direct reading method) of L value 62.8, b value 0.5, haze 0.2% Using terephthalate, 57 parts by mass of polyethylene terephthalate, 10 parts by mass of (PBT / PTMG) copolymer of polybutylene terephthalate and polytetramethylene glycol (trade name: Hytrel manufactured by Toray DuPont Co., Ltd.), against ethylene glycol 10 parts by mass of copolymerized polyethylene terephthalate (33 mol% CHDM copolymerized PET) in which 33 mol% of 1,4-cyclohexanedimethanol was copolymerized and 23 parts by mass of poly (5-methyl) norbornene were prepared and mixed at 180 ° C. for 3 hours. After drying,
  • Extruder A heated to 280 ° C. (A layer).
  • a layer A layer
  • the unstretched film obtained by cooling and solidifying this film with a cooling drum having a surface temperature of 25 ° C. was led to a roll group heated to 85 to 98 ° C., longitudinally stretched 3.7 times in the longitudinal direction, and cooled with a roll group at 21 ° C. . Subsequently, the film was stretched by 3.6 times in a direction perpendicular to the longitudinal direction in an atmosphere heated to 120 ° C.
  • Examples 2 to 30 A white polyester film was obtained in the same manner as in Example 1, except that the raw material composition of the A layer and B layer, the thickness of the A layer, and the total film thickness were changed as described in Table 1.
  • Example 1 since the content of silicon dioxide was small, the luminance unevenness was slightly inferior, and since the content of rutile-type titanium oxide was small, the light resistance was slightly lower than the other examples. It was inferior. Although the content of barium sulfate was small, the luminance was at a level that could be used practically.
  • Example 2 since the contents of silicon dioxide and barium sulfate were larger, the film-forming stability was slightly inferior to those of the other examples, and the content of rutile titanium oxide was larger. was slightly inferior to the other examples.
  • Example 3 since the number average particle diameter of silicon dioxide was smaller, the luminance unevenness was slightly inferior to the other examples, and the number average particle diameter of rutile-type titanium oxide was smaller, so that the light resistance was high. It was slightly inferior to the other examples. Although the number average particle size of barium sulfate was smaller, the luminance was at a level that could be used practically.
  • Example 4 since the number average molecular weights of silicon dioxide and barium sulfate were larger, the film-forming stability was slightly inferior to the other examples, and the number average particle diameter of rutile titanium oxide was larger. Therefore, the light resistance was slightly inferior to the other examples.
  • Example 5 since the content of silicon dioxide was small, the luminance unevenness was slightly inferior to the other examples, and the content of rutile type titanium oxide was small, so that the light resistance was another example. Was slightly inferior to. Although the content of barium sulfate was small, the luminance was at a level that could be used practically.
  • Example 6 since the contents of silicon dioxide and barium sulfate were higher, the film-forming stability was slightly inferior to those of the other examples, and the content of rutile titanium oxide was higher. was slightly inferior to the other examples.
  • Example 7 since the number average particle diameter of silicon dioxide was smaller, the luminance unevenness was slightly inferior to the other examples, and the number average particle diameter of rutile-type titanium oxide was smaller, so that the light resistance was high. It was slightly inferior to the other examples. Although the number average particle size of barium sulfate was smaller, the luminance was at a level that could be used practically.
  • Example 8 since the number average molecular weights of silicon dioxide and barium sulfate were larger, the film forming stability was slightly inferior to those of the other examples. Although the number average particle size of rutile type titanium oxide was large, the light resistance was at a level that could be used practically.
  • Comparative Example 1 A film having a thickness of 188 ⁇ m was obtained in the same manner as in Example 1 except that the laminated structure and the raw material composition were changed as described in Table 1. Although the film formation is stable and the relative reflectance is 104.2% and high luminance is obtained even in the relative luminance, the silicon dioxide is not added to the A layer. It was insufficient.
  • Example 2 A film having a thickness of 188 ⁇ m was obtained in the same manner as in Example 1 except that the laminated structure and the raw material composition were changed as described in Table 1. Although the relative reflectance was 104.3% and a high value was obtained even in the relative luminance, the light resistance was insufficient because no rutile-type titanium oxide was added to the A layer.
  • Comparative Example 3 A film having a thickness of 188 ⁇ m was obtained in the same manner as in Example 1 except that the laminated structure and the raw material composition were changed as described in Table 1.
  • Example 5 A film having a thickness of 188 ⁇ m was obtained in the same manner as in Example 1 except that the laminated structure and the raw material composition were changed as described in Table 1. The film was stable, the relative reflectance was 103.8%, and a high luminance was obtained even with the relative luminance, but the luminance unevenness was insufficient because the A layer was thick.
  • Comparative Example 6 A film having a thickness of 250 ⁇ m was obtained in the same manner as in Example 1 except that the laminated structure and the raw material composition were changed as described in Table 1. Although the relative reflectance was 102.0% and the relative luminance was also high, there was a scratch on the light guide plate because no silicon dioxide was added to the A layer, and no rutile titanium oxide was added.
  • Example 7 A film having a thickness of 225 ⁇ m was obtained in the same manner as in Example 1 except that the laminated structure and the raw material composition were changed as described in Table 1. However, in order to obtain a two-layer lamination of A / B layers, lamination was performed with a feed block, and a sheet was extruded from a T-die to obtain a molten sheet. Although the film-forming stability was insufficient, the relative reflectance was 103.0%, and a high value was obtained even in the relative luminance, but there was a scratch on the light guide plate and the light resistance was insufficient.
  • Example 8 A film having a thickness of 225 ⁇ m was obtained in the same manner as in Example 1 except that the laminated structure and the raw material composition were changed as described in Table 1. However, since the raw material was not supplied to the extruder A and the A layer was not formed, it became a single layer film of only the B layer. There was film-forming stability, the relative reflectance was 100.0%, there were scratches on the light guide plate, and the relative luminance, luminance unevenness and light resistance were insufficient.
  • PET Polyethylene terephthalate
  • PET / I / PEG ethylene glycol / terephthalic acid / isophthalic acid cocondensate (polyethylene terephthalate copolymer in which 5 mol% of polyethylene glycol having a molecular weight of 1,000 is copolymerized)
  • PET / CHDM polyethylene-1,4-cyclohexylenedimethylene terephthalate (polyethylene terephthalate copolymer obtained by copolymerizing 33 mol% of 1,4-cyclohexanedimethanol with respect to ethylene glycol)
  • PBT / PTMG Polyester ether elastomer mabutylene / poly (alkylene ether) phthalate (copolymer having 30 mol% of alkylene glycol with respect to butylene terephthalate) (trade name: Hytrel manufactured by Toray DuPont) It is.
  • the white polyester film of the present invention is suitably used for large direct-type light-type liquid crystal displays used for televisions and the like, and small sidelight-type liquid crystal displays used for notebook computers and mobile phones. Moreover, it can be used as a back sheet for solar cells, and contributes to the efficiency of conversion from sunlight to electricity, and can impart resistance to ultraviolet rays from sunlight.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Nonlinear Science (AREA)
  • Electromagnetism (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Mathematical Physics (AREA)
  • Computer Hardware Design (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Planar Illumination Modules (AREA)
  • Laminated Bodies (AREA)
  • Liquid Crystal (AREA)
  • Optical Elements Other Than Lenses (AREA)

Abstract

L'invention concerne un film de polyester blanc qui comprend au moins une couche A faite de polyester et une couche B faite de polyester, dans lequel la couche B comprend des bulles, la couche A contient trois composés minéraux, à savoir de l'oxyde de titane rutile, du sulfate de baryum et du dioxyde de silicium, le film de polyester blanc possède une épaisseur totale de 100-500 μm, et la couche A possède une épaisseur de 2-16 μm. L'invention concerne un film de polyester blanc réfléchissant la lumière qui permet d'obtenir un niveau de luminosité élevé lorsqu'il est utilisé avec un affichage à cristaux liquides, et qui est excellent en termes de résistances aux UV et qui est moins onéreux que ceux de l'art antérieur. Le film de polyester blanc possède également d'excellentes performances en termes de réflexion et une excellente résistance aux UV lorsqu'il est utilisé comme film arrière pour une cellule solaire.
PCT/JP2011/053633 2010-03-23 2011-02-21 Film de polyester blanc, plaque réfléchissant la lumière le comprenant, et rétro-éclairage d'affichage à cristaux liquides le comprenant WO2011118305A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2011522311A JP5045851B2 (ja) 2010-03-23 2011-02-21 白色ポリエステルフィルム、それを用いた光反射板および液晶ディスプレイ用バックライト
KR1020127022727A KR101772015B1 (ko) 2010-03-23 2011-02-21 백색 폴리에스테르 필름, 그것을 사용한 광반사판 및 액정 디스플레이용 백라이트
CN201180010943.7A CN102782532B (zh) 2010-03-23 2011-02-21 白色聚酯膜、使用其的光反射板以及液晶显示器用背光源

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010065659 2010-03-23
JP2010-065659 2010-03-23

Publications (1)

Publication Number Publication Date
WO2011118305A1 true WO2011118305A1 (fr) 2011-09-29

Family

ID=44672877

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2011/053633 WO2011118305A1 (fr) 2010-03-23 2011-02-21 Film de polyester blanc, plaque réfléchissant la lumière le comprenant, et rétro-éclairage d'affichage à cristaux liquides le comprenant

Country Status (5)

Country Link
JP (1) JP5045851B2 (fr)
KR (1) KR101772015B1 (fr)
CN (1) CN102782532B (fr)
TW (1) TWI495898B (fr)
WO (1) WO2011118305A1 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014021476A1 (fr) * 2012-08-03 2014-02-06 帝人デュポンフィルム株式会社 Film réfléchissant blanc
JP2014032310A (ja) * 2012-08-03 2014-02-20 Teijin Dupont Films Japan Ltd 白色反射フィルム
JP2014142650A (ja) * 2014-03-05 2014-08-07 Teijin Dupont Films Japan Ltd 白色反射フィルム
JP2014146038A (ja) * 2014-03-05 2014-08-14 Teijin Dupont Films Japan Ltd 白色反射フィルム
CN104246545A (zh) * 2012-07-30 2014-12-24 东丽株式会社 液晶显示器用白色聚酯膜
JP2016108504A (ja) * 2014-12-10 2016-06-20 東レ株式会社 二軸配向ポリエステルフィルム
WO2016152638A1 (fr) * 2015-03-20 2016-09-29 東洋紡株式会社 Film de polyester blanc pour une cellule solaire, feuille d'étanchéité arrière comprenant ce dernier pour une cellule solaire et module de cellule solaire

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101599684B1 (ko) * 2013-02-25 2016-03-07 데이진 듀폰 필름 가부시키가이샤 백색 반사 필름
KR20160089360A (ko) * 2013-11-21 2016-07-27 도레이 카부시키가이샤 2축 배향 폴리에스테르 필름 및 그의 제조 방법
CN113978083B (zh) * 2021-10-20 2024-01-23 天津万华股份有限公司 一种用于电子元件的无硅亚光聚酯薄膜

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04239540A (ja) * 1991-01-22 1992-08-27 Toray Ind Inc 液晶ディスプレイ反射板用白色ポリエステルフイルム
JP2007121814A (ja) * 2005-10-31 2007-05-17 Toray Ind Inc 面光源反射部材用白色フィルム

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0496323B2 (fr) * 1991-01-22 2002-12-11 Toray Industries, Inc. Réflecteur pour source lumineuse plane
US20040119189A1 (en) * 2002-12-23 2004-06-24 Eastman Kodak Company Indicia on foam core support media
US20070092710A1 (en) * 2003-10-17 2007-04-26 Mitsubishi Plastics, Inc. Reflective film
CN1934140A (zh) * 2004-03-08 2007-03-21 生态涂料公司 用于涂覆金属物体的环境友好的涂料组合物、由其涂覆的物体、及其涂覆的方法、工艺和组合系统
US20100279091A1 (en) * 2005-12-22 2010-11-04 Mitsubishi Plastics, Inc. Reflective film
EP2077458A4 (fr) * 2006-10-27 2012-03-28 Toray Industries Film en polyester blanc destiné à une plaque réfléchissant la lumière
TW200827763A (en) * 2006-12-25 2008-07-01 Eternal Chemical Co Ltd Scratch-resistant optical film
TWI374922B (en) * 2006-12-29 2012-10-21 Eternal Chemical Co Ltd Anti-uv coating composition and the use thereof
JP5166740B2 (ja) * 2007-02-06 2013-03-21 帝人デュポンフィルム株式会社 反射板用白色ポリエステルフィルム
KR20090009107A (ko) * 2007-07-19 2009-01-22 도레이 카부시키가이샤 백색 폴리에스테르필름
TW200937043A (en) * 2008-02-29 2009-09-01 Eternal Chemical Co Ltd Brightness enhancement reflective film
JP2009237435A (ja) * 2008-03-28 2009-10-15 Toray Ind Inc 光反射性フィルムおよびそれを用いた画像表示用バックライト装置

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04239540A (ja) * 1991-01-22 1992-08-27 Toray Ind Inc 液晶ディスプレイ反射板用白色ポリエステルフイルム
JP2007121814A (ja) * 2005-10-31 2007-05-17 Toray Ind Inc 面光源反射部材用白色フィルム

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104246545A (zh) * 2012-07-30 2014-12-24 东丽株式会社 液晶显示器用白色聚酯膜
JPWO2014021207A1 (ja) * 2012-07-30 2016-07-21 東レ株式会社 液晶ディスプレイ用白色ポリエステルフィルム
CN104246545B (zh) * 2012-07-30 2017-05-24 东丽株式会社 液晶显示器用白色聚酯膜
TWI595271B (zh) * 2012-08-03 2017-08-11 Teijin Dupont Films Japan Ltd White reflective film
JP2014032310A (ja) * 2012-08-03 2014-02-20 Teijin Dupont Films Japan Ltd 白色反射フィルム
TWI632403B (zh) * 2012-08-03 2018-08-11 日商帝人都朋軟片股份有限公司 White reflective film
TWI632402B (zh) * 2012-08-03 2018-08-11 日商帝人都朋軟片股份有限公司 White reflective film
CN104603647A (zh) * 2012-08-03 2015-05-06 帝人杜邦薄膜日本有限公司 白色反射性膜
CN105866867B (zh) * 2012-08-03 2017-10-31 帝人杜邦薄膜日本有限公司 白色反射性膜
CN105866867A (zh) * 2012-08-03 2016-08-17 帝人杜邦薄膜日本有限公司 白色反射性膜
CN105866866A (zh) * 2012-08-03 2016-08-17 帝人杜邦薄膜日本有限公司 白色反射性膜
WO2014021476A1 (fr) * 2012-08-03 2014-02-06 帝人デュポンフィルム株式会社 Film réfléchissant blanc
JP2014146038A (ja) * 2014-03-05 2014-08-14 Teijin Dupont Films Japan Ltd 白色反射フィルム
JP2014142650A (ja) * 2014-03-05 2014-08-07 Teijin Dupont Films Japan Ltd 白色反射フィルム
JP2016108504A (ja) * 2014-12-10 2016-06-20 東レ株式会社 二軸配向ポリエステルフィルム
WO2016152638A1 (fr) * 2015-03-20 2016-09-29 東洋紡株式会社 Film de polyester blanc pour une cellule solaire, feuille d'étanchéité arrière comprenant ce dernier pour une cellule solaire et module de cellule solaire
US20180062013A1 (en) * 2015-03-20 2018-03-01 Toyobo Co., Ltd. White polyester film for a solar cell, sealing sheet for back surface of solar cell using same, and solar cell module
CN107408595A (zh) * 2015-03-20 2017-11-28 东洋纺株式会社 太阳能电池用白色聚酯薄膜、使用其的太阳能电池背面密封片材及太阳能电池组件
KR20170128773A (ko) 2015-03-20 2017-11-23 도요보 가부시키가이샤 태양전지용 백색 폴리에스테르 필름, 이를 사용한 태양전지 이면 봉지 시트 및 태양전지 모듈
US10475943B2 (en) * 2015-03-20 2019-11-12 Toyobo Co., Ltd. White polyester film for a solar cell, sealing sheet for back surface of solar cell using same, and solar cell module
CN107408595B (zh) * 2015-03-20 2020-03-10 东洋纺株式会社 太阳能电池用白色聚酯薄膜、使用其的太阳能电池背面密封片材及太阳能电池组件

Also Published As

Publication number Publication date
CN102782532A (zh) 2012-11-14
CN102782532B (zh) 2015-04-15
TW201137384A (en) 2011-11-01
KR20130018668A (ko) 2013-02-25
KR101772015B1 (ko) 2017-08-28
JPWO2011118305A1 (ja) 2013-07-04
TWI495898B (zh) 2015-08-11
JP5045851B2 (ja) 2012-10-10

Similar Documents

Publication Publication Date Title
JP5045851B2 (ja) 白色ポリエステルフィルム、それを用いた光反射板および液晶ディスプレイ用バックライト
JP5292812B2 (ja) 光反射板用白色ポリエステルフィルム
JP4889055B2 (ja) 白色反射フィルム
US20090042016A1 (en) White polyester film
JP6295664B2 (ja) 液晶ディスプレイ用白色ポリエステルフィルム、その製造方法及び液晶ディスプレイ用バックライト
JP2012135952A (ja) 白色ポリエステルフィルム
JP5532799B2 (ja) 白色反射フィルム
JP5040647B2 (ja) 面光源反射部材用フィルム
JP5464997B2 (ja) 光反射体及び面光源装置
JP2007178505A (ja) ディスプレイ反射板用白色ポリエステルフイルム
JP5391617B2 (ja) 白色フィルムおよびそれを用いた面光源
JP5353178B2 (ja) ポリエステルフィルムならびにそれを用いた液晶ディスプレイ用バックライトおよび太陽電池用
JP2008286907A (ja) 反射用積層体
JP2007072429A (ja) 液晶ディスプレー反射板用白色ポリエステルフイルム
JP2013136232A (ja) 光反射板用ポリエステルフィルム
JP2007140499A (ja) 光拡散部材およびそれを用いた面光源
JP6880521B2 (ja) 光反射フィルムおよびエッジライト型バックライト
JP2014126638A (ja) 液晶ディスプレイ用反射フィルム
JP2018169456A (ja) 白色反射フィルム

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 201180010943.7

Country of ref document: CN

WWE Wipo information: entry into national phase

Ref document number: 2011522311

Country of ref document: JP

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11759113

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20127022727

Country of ref document: KR

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11759113

Country of ref document: EP

Kind code of ref document: A1