WO2005096036A1 - 反射シート及びその製造方法 - Google Patents
反射シート及びその製造方法 Download PDFInfo
- Publication number
- WO2005096036A1 WO2005096036A1 PCT/JP2005/006090 JP2005006090W WO2005096036A1 WO 2005096036 A1 WO2005096036 A1 WO 2005096036A1 JP 2005006090 W JP2005006090 W JP 2005006090W WO 2005096036 A1 WO2005096036 A1 WO 2005096036A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- resin
- sheet
- volume
- polypropylene
- less
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/08—Mirrors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
- B29C55/005—Shaping by stretching, e.g. drawing through a die; Apparatus therefor characterised by the choice of materials
-
- 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
- G02B5/0247—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place within the volume of the element by means of voids or pores
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/02—Diffusing elements; Afocal elements
- G02B5/0268—Diffusing elements; Afocal elements characterized by the fabrication or manufacturing method
-
- 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
- G02B5/12—Reflex reflectors
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
- B29K2023/10—Polymers of propylene
- B29K2023/12—PP, i.e. polypropylene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
- B29K2105/04—Condition, form or state of moulded material or of the material to be shaped cellular or porous
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
- B29K2995/0018—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular optical properties, e.g. fluorescent or phosphorescent
- B29K2995/003—Reflective
-
- 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
Definitions
- the present invention relates to a reflection sheet of a resin composition having pores therein, and particularly to a reflection sheet suitable for a reflection material used for a knock light or the like of a liquid crystal display device.
- a liquid crystal display device is composed of a liquid crystal panel, such as a liquid crystal, an alignment plate, an electrode, and a polarizing plate, which has a strong force, and a device for irradiating the panel with light, and a lighting device generally called a backlight.
- a reflective sheet is used for efficient reflection.
- the backlight of a liquid crystal display device is generally classified into two types, an edge light type backlight and a direct type backlight.
- the edge light type backlight is a backlight often used for a small liquid crystal display device used for a mobile phone, a personal digital assistant, and the like.
- An edge-light type backlight is a light source such as a light-emitting diode or a cold cathode ray tube, an optical path generally called a light guide plate formed of transparent resin such as acrylic resin in a wedge shape, and the side of the light guide plate opposite to the liquid crystal panel.
- a light source such as a light-emitting diode or a cold cathode ray tube
- an optical path generally called a light guide plate formed of transparent resin such as acrylic resin in a wedge shape, and the side of the light guide plate opposite to the liquid crystal panel.
- a light source such as a light emitting diode or a cold cathode ray tube is often installed at a position adjacent to the end face of the light guide plate.
- Light from the light source is incident on the end face of the light guide plate.
- Light incident on the light guide plate exits the light guide plate from the side surface of the light guide plate while passing through the light guide plate.
- the light on the LCD panel side of the light guide plate also illuminates the LCD panel. The light on the opposite side of the light guide plate from the LCD panel can illuminate the LCD panel.
- a reflective sheet that reflects light is installed on the side of the light guide plate opposite to the liquid crystal panel side, and the light that goes out of the light guide plate is reflected to the liquid crystal panel side, and the light source It is common practice to effectively irradiate the liquid crystal panel with light.
- liquid crystal display devices Since mobile phones and personal digital assistants are often used outdoors, liquid crystal display devices If the LCD device is illuminated by external light such as sunlight that is brighter than the light source, the LCD screen may be difficult to see.Therefore, a reflective sheet with high reflectance should be set on the back side of the LCD panel. Accordingly, bright external light, such as sunlight, incident on the liquid crystal display device is often reflected to make the liquid crystal display screen easier to see.
- a direct-type backlight is a backlight in which multiple light source lamps such as cold cathode ray tubes are arranged side by side on the opposite side of the display surface of the liquid crystal panel, and is used for large-screen liquid crystal display devices used in large televisions and the like. Used.
- the brightness of the light source lamp is limited in order to increase the brightness to a level that satisfies the brightness of the edge light type knock light, so a direct type backlight using multiple light source lamps is usually used Have been.
- the light from the light source lamp is also radiated to the side opposite to the liquid crystal side, it is necessary to provide a reflective sheet on the side opposite to the liquid crystal side of the light source lamp so that the light from the light source can be effectively radiated to the liquid crystal panel. This is commonly done in type backlights.
- a knock sheet used in a liquid crystal display device often uses a reflection sheet or film having a reflectance of 90% or more.
- the resin used for the reflection sheet needs to have a heat resistance of approximately 80 ° C, which is close to the heat resistance temperature of the liquid crystal material. For this reason, there is a demand for a reflection sheet of a resin composition which is easily formed into a sheet and has excellent heat resistance as a reflection sheet used for a knock light of a liquid crystal display device.
- a large-area reflective sheet is illuminated with strong light for a long period of time. For this reason, there is a demand for a reflective sheet that has little discoloration or deterioration due to light from a light source, and is less likely to be deformed over a long period of time, such as warpage due to temperature rise or moisture absorption.
- the resin to which the inorganic powder is added is stretched so that the interface between the resin and the inorganic powder is cleaved.
- the resin to which the inorganic powder is added is stretched so that the interface between the resin and the inorganic powder is cleaved.
- Known are those that have pores formed inside the resin, and (2) those that dissolve a pressurized inert gas in the resin and then reduce the pressure to foam to form bubbles inside the resin. ing.
- Patent Document 1 discloses a polyethylene terephthalate resin containing 5 to 30 wt% of fine particle calcium carbonate, which is melt-extruded and biaxially stretched, and a void fraction calculated from a density.
- a sheet of white polyethylene terephthalate having a content of 7 to 30% is disclosed.
- an inert gas such as carbon dioxide gas is dissolved in a thermoplastic polyester under a pressurized atmosphere, and then heated and foamed under normal pressure.
- a light reflection sheet containing microbubbles is disclosed!
- the reason why the resin containing pores and bubbles inside reflects light well is considered as follows. Since the refractive index of resin is approximately 1.4 to 1.6 and the refractive index of air is about 1, the reflectivity of light caused by the difference between the refractive index of resin and air is about one per reflection. Only 4%. However, in a resin sheet containing a large number of pores / bubbles inside, a large number of interfaces between resin and air exist inside, so that the light applied to the sheet is reflected many times inside the sheet. As a result, in a resin sheet containing a large number of holes and bubbles inside, it is considered that the irradiated light is largely reflected inside the sheet, and as a result, the reflectance of the entire sheet is increased.
- specular reflection In contrast to diffuse reflection, reflection in which the angle at which light is incident on the reflecting surface and the angle of reflected light are symmetrical is called specular reflection, and the reflecting surface of the specular reflecting sheet has a mirror-like shape.
- the surface of the polyester resin sheet should not be deposited.
- What is known is a method in which the reflectance of silver or the like is large and coated with a substance by any method, and a reflection sheet in which several hundred layers of resins having different refractive indexes and a thickness smaller than the wavelength of visible light is laminated.
- a resin sheet having a high light reflectance is used as a reflector for a lamp of a projector or a headlight or a reflector of a backlight of a liquid crystal display device.
- a resin reflection sheet satisfying these conditions includes a polyester-based resin-polypropylene resin, as described in (1) above, in which an inorganic powder is added to the resin and stretched to form a hole in the interior.
- the reflective sheet (1) since inorganic powders such as calcium carbonate and barium sulfate are contained in a large ratio of several tens of volume% of the entire reflective sheet, a part of the inorganic powder protrudes from the surface of the reflective sheet. There are many. When such a reflection sheet is used in an edge light type backlight, the surface of the light guide plate is likely to be damaged by inorganic powder partially projecting from the surface of the reflection sheet in the step of bonding the reflection sheet to the light guide plate.
- the inorganic powder may be detached from the surface of the reflective sheet or the end face and adhere to the surface of the reflective sheet or the surface of the backlight, etc., which may appear as dots on the liquid crystal screen, thereby deteriorating the image quality of the display screen. There is.
- the reflection sheet of (2) is a resin reflection sheet containing no inorganic powder, but in order to dissolve the inert gas in the resin sheet, the resin sheet is placed under a pressurized inert gas atmosphere. It is necessary to keep it for a certain period of time, and it is necessary to take out a resin sheet in which the inert gas is dissolved, return it to normal pressure, and then heat and foam it.
- the reflection sheet of (3) is formed by a metal particle such as silver which covers the surface of the resin sheet. It is known that the metal such as silver discolors immediately after being oxidized and the reflectance is reduced. For this reason, it prevents contact with the atmosphere on metal particles such as silver that cover the surface of the sheet.
- the process of applying a thin metal or resin multiple times on the surface of the resin sheet is required, and the manufacturing process is a powerful and complicated process. It is easy to be.
- the reflection sheet (3) is a sheet that causes specular reflection, but a direct-type backlight used in large-screen liquid crystal display devices such as large televisions uses a reflection sheet that causes regular reflection. It is known that, when used, light from a plurality of light source lamps interferes to cause unevenness in the brightness of a liquid crystal screen. For this reason, a reflection sheet that causes diffuse reflection is often used for a direct backlight.
- the reflection sheets (1) and (2) are also reflection sheets that cause diffuse reflection.
- a large amount of inorganic particles added to the reflection sheet may damage the light guide plate or cause the inorganic particles to fall off.
- Patent Document 3 discloses 65-93% by weight of polypropylene and 5-20% by weight of an incompatible resin as a white resin film having pores formed therein without adding inorganic particles.
- White Power that a biaxially stretched polyolefin film is disclosed Power that can be used as a white film used for printing paper, labels, etc. High and reflectivity that can be used for backlights of liquid crystal display devices, etc. Difficult to get.
- Patent Document 1 Japanese Patent Publication No. 6-89160
- Patent Document 2 Japanese Patent No. 2925745
- Patent Document 3 Japanese Patent No. 3139510
- the present inventor has conducted intensive studies to solve the above-mentioned problems.
- more than half of the resin is polypropylene resin (A), and the remaining majority is at a temperature at which the polypropylene resin can be stretched.
- the resin composition (B), which is phase-separated from propylene, is stretched to form pores inside.
- ⁇ ⁇ It can be obtained by a general and simple, drawn resin sheet or film manufacturing facility. Have led to the present invention.
- the present invention is as follows.
- polypropylene ⁇ (A) less than 50 volume 0/0 over 80 vol 0/0, ⁇ of polypropylene ⁇ and phase separation extending extension which can temperature polypropylene ⁇ (B) 20 vol%
- a reflective sheet comprising a resin composition containing less than 50% by volume and having pores therein, wherein the length in the plane direction of the resin (B) phase in the thickness direction cross section of the reflective sheet (X ) And the standard deviation of the ratio (XZZ) of the length in the thickness direction (Z) to 0.2 or more.
- the resin composition is such that the polypropylene resin (A) is 50% by volume or more and less than 65% by volume, and a resin which phase-separates with the polypropylene resin at a temperature at which the polypropylene resin can be stretched (B)
- the resin composition contains a polystyrene resin, and a resin (B) which phase-separates with the polypropylene resin at a temperature at which the polypropylene resin can be stretched, and a polystyrene resin in total.
- a reflection sheet that does not contain a large amount of inorganic powder and that diffuses and reflects.
- a strong reflection sheet has a high reflectance of 90% or more, and is a general and simple extension sheet. ⁇ Can be obtained with equipment for manufacturing resin sheets and films.
- the reflective sheet according to the present invention comprises a polypropylene resin (A) having a volume of 50% by volume or more and less than 80% by volume, and a resin (B) which is phase-separated from the polypropylene resin at a temperature at which the polypropylene resin can be stretched.
- a reflective sheet comprising a resin composition containing less than 10% by volume and having pores therein, wherein a length (X) of a resin (B) phase in a plane direction of a cross section in a thickness direction of the reflective sheet.
- the polypropylene resin (A) used in the present invention is a polypropylene resin such as a homopolymer of propylene or a copolymer with a monomer such as ethylene which can be copolymerized with propylene.
- the polypropylene resin (A) may be a polypropylene resin whose melt flow rate measured at 230 ° C and a load of 21.2N according to JISK7210 is 0.1 to 10 gZ. preferable.
- the melt flow rate is preferably 0.1 lgZ min or more from the viewpoint of the load of the extruder and the discoloration of the resin composition due to heat when melt molding polypropylene resin. From the viewpoint of, it is preferable that the amount is not more than 10gZ.
- the proportion of the polypropylene resin (A) in the entire resin composition is preferably 50% by volume or more.
- a sheet extruded from the resin composition is stretched to form a hole in the sheet to obtain a high reflectance sheet of 90% or more.
- the percentage of resin (A) is less than 80%.
- the resin (B) that is phase-separated from the polypropylene resin at a temperature at which the polypropylene resin can be stretched includes polyethylene resin, polystyrene resin, polymethyl methacrylate resin, polycarbonate resin, and poly- ylene resin.
- Examples include polycycloolefin resin such as methylpentene resin and polynorbornene resin, polyester resin, and polyamide resin.
- a resin having a higher elastic modulus at a temperature at which the propylene resin can be stretched than a polypropylene resin is more preferable.
- Polycycloolefin resin polyester resin, polyamide resin and the like. It is most preferable to use at least one kind of resin melt-mixed with polypropylene resin due to the power of these resins, and it is most preferable to use polycarbonate resin.
- the volume of the entire resin composition is reduced. 20% or more and less than 50% are resin (B).
- the resin (B) is less than 50% by volume of the entire resin composition from the viewpoint of reducing the stretching tension. From the viewpoint of increasing the number of pores and the volume of the sheet to obtain high reflectance, the resin (B) is preferably at least 20% by volume of the entire resin composition. From the viewpoint of the tension at the time of stretching the resin, the resin (B) is preferably less than 50% of the whole resin composition.
- inorganic particles for forming pores in the resin composition are not added to the resin composition.
- a small amount of fine silica about 100 ppm as a lubricant as a lubricant.
- the reflection sheet of the present invention comprises, for example, a polypropylene resin (A) containing at least 50% by volume and at least 80% by volume. % And less than 20% by volume and less than 50% by volume of the resin (B), and the islands of the resin (B) are dispersed in the sea of polypropylene resin. It is obtained by extruding the fat composition into a sheet and then stretching it.
- A polypropylene resin
- B the islands of the resin
- the resin (B) phase contained in the reflection sheet of the present invention has a constant ratio of the length in the plane direction (X) to the length in the thickness direction (Z) in the cross section in the thickness direction of the reflection sheet. It has a distribution but not! Specifically, the value of the standard deviation of the ratio of X and Z (XZZ) is 0.2 or more.
- the value of the standard deviation of XZZ is too large, the excessive resin (B) phase which tends to cause the sheet to break during stretching increases, or the excessive resin (B ) Because the number of phases tends to increase, the value of the standard deviation of XZZ is too large, and the standard deviation of XZZ generally does not exceed 5.
- the effect of having the ratio of the length (X) in the plane direction of the resin (B) phase to the length (Z) in the thickness direction having a distribution is considered as follows.
- the resin (B) phase having a certain shape such as a sphere
- the resin (B) phases tend to come into contact with each other to form an aggregate.
- the resin (B) phase takes on various shapes and disperses in the polypropylene resin sea phase
- the resin (B) phase aggregates and then disperses in a certain shape.
- the number of resin (B) phases contained in the entire resin can be increased.
- the raw material is separated from the resin pellets by mechanical force.
- the degree is moderate, and the distribution of the resin (B) phase shape is wide.
- the value of the standard deviation of XZZ is large.
- those having an elastic modulus at a temperature at which the polypropylene resin can be stretched are higher than those of the polypropylene resin. The reason is considered as follows.
- the resin composition sheet is stretched at a temperature at which the polypropylene resin can be stretched to cleave the interface between the resin (B) phase and the polypropylene resin (A) phase in the resin composition. This causes a hole to be formed inside the sheet.
- the elasticity of the resin (B) is greater than the elastic modulus of the polypropylene resin (A), and the amount of deformation of the resin (B) phase due to the stretching force is the polypropylene resin (A). It is considered that the interface between the resin (B) phase and the polypropylene resin (A) phase is more likely to be cleaved because it is smaller than the deformation amount of the phase.
- Polycarbonate resin which is a preferred example of the resin (B) of the present invention U, may be used alone or in combination with aromatic polycarbonate, linear polycarbonate, and branched polycarbonate. Can be.
- a polycarbonate resin having a melt flow rate of 0.1 to 50 gZlO measured by a method of JISK7210 at a temperature of 300 ° C. and a load of 11.8 N is preferable.
- the melt flow rate of the polycarbonate resin is preferably 0.1 lgZio or more.
- the melt flow rate is preferably 50 gZlO or less.
- Examples of the resin (B) other than the polycarbonate resin include polyamide resin.
- Polyamide and resin can be used alone or in combination from the power of polyamide, 66, polyamide, 6, polyamide, 610, polyamide, 612, polyamide, 11, polyamide 12, aromatic polyamide, etc. .
- the polyamide resin is preferably a polyamide resin having a melting point of 300 ° C. or less from the viewpoint of dispersibility when extruded by an extruder.
- a polystyrene resin can be used in addition to the polypropylene resin (A) and the resin (B).
- the polystyrene resin a polystyrene resin having a melt flow rate of 0.1 to 20 gZl per minute at a temperature of 200 ° C and a load of 49 N according to the method of JISK7210 is preferable.
- JISK7210 a polystyrene resin having a melt flow rate of 0.1 to 20 gZl per minute at a temperature of 200 ° C and a load of 49 N according to the method of JISK7210 is preferable.
- the ratio of polystyrene resin to the entire resin composition is 5 volumes. % Or less is preferable.
- a resin composition obtained by mixing a polypropylene resin (A), a resin (B) and, if necessary, a polystyrene resin is used.
- a light stabilizer, a heat stabilizer, a nucleating agent, an antistatic agent, and the like is used.
- the sheet thickness of the reflection sheet of the present invention is not particularly limited, but is preferably 10
- 500500 ⁇ m more preferably 30-300 ⁇ m.
- the reflectance of the sheet of the present invention is not particularly limited. However, when the sheet is used as a reflection sheet used for a backlight of a liquid crystal display device, the brightness of the screen when used for the backlight of the liquid crystal display device is used. From the viewpoint of the reflectance, it is preferable that the reflectance is 90% or more. When the reflectance is in the above range, the brightness of the light emitting diode or the cold cathode ray tube, which is the light source of the liquid crystal display device, can be used effectively, so that the screen brightness can be set to a necessary and sufficient level. It is preferable from the viewpoint of power consumption, heat generation of the light source, and the like.
- the porosity is not particularly limited. However, when used in a liquid crystal display device of a device mainly used outdoors such as a mobile phone, the porosity is 30% or more for light weight. It is preferable that there is.
- the polypropylene resin (A) is 50% by volume or more and less than 80% by volume, and the resin (B) which is phase-separated from the polypropylene resin is 20% by volume or less. It is preferable that the resin composition containing less than 50% by volume is melted and then stretched. More preferably, a resin composition containing 50% to less than 65% by volume of polypropylene resin (A) and 35% to less than 50% by volume of resin (B) is used.
- an extruder to mix and melt the resin composition.
- a co-rotating twin screw extruder has a large effect of melting and mixing the raw resin and is preferable.
- a single-screw extruder use a screw with a mixing function, such as a pin mixer or a dial mage, as the extruder screw, or use a twin-screw It is preferable to use a single-screw extruder that has been melt-mixed in an extruder and added to a pellet.
- the raw resin melt-mixed in the extruder is extruded into a die-strength sheet attached to the tip of the extruder, and the extruder is used to stabilize the amount of the extruded resin composition.
- a gear pump may be used between the dies.
- a sheet forming die such as a T-die fishtail die is used.
- the resin (B) is stretched in the flow direction inside the sheet extruded from the die, and the resin (B) is added to the sea in the polypropylene resin.
- the conventional sheet, in which the sheet with this structure is stretched and a hole is formed inside, has a different amount of reflected light depending on the direction of the sheet.
- Features not found in reflective sheets can also be provided.
- the sheet extruded with the die force is cooled and fixed by a cooling roller or the like, and then stretched by a stretching machine.
- the stretching ratio is preferably 18 times or less from the viewpoint of the volume ratio of the holes to the entire sheet.
- the stretching is a longitudinal stretching step in which the sheet is passed through a plurality of rollers at different speeds to stretch the sheet in the flowing direction, and a transverse stretching step in which the sheet is stretched in the width direction using a clip tenter or the like.
- the stretching step can be performed alone or in combination.
- a simultaneous biaxial stretching machine such as a pantograph stretching machine is used to simultaneously stretch in the flow direction and the width direction.
- the stretching step of the present invention it is preferable to perform stretching at a temperature as low as possible in order to generate holes inside the sheet.
- a temperature as low as possible in order to generate holes inside the sheet.
- the stretching ratio is larger than that when the film is stretched at a low temperature.
- a transparent sheet to a highly concealable sheet having a high reflectance can be produced, and the ratio of reflected light to transmitted light can be set arbitrarily. It also has the feature of being able to.
- the resin composition is a combination of a polypropylene resin (A) and a polycarbonate resin (B)
- a sheet with a high concealing property having a reflectance of 90% or more when stretched at 155 ° C is obtained.
- stretched at 160 ° C. a transmissive sheet having a small reflectance of several percent can be obtained.
- the thickness of the sheet was measured using a thickness gauge manufactured by Peacock.
- the porosity of the sheet is calculated from the specific gravity of each resin used and the true specific gravity calculated by weight specific force, and the apparent specific gravity obtained by dividing the weight of the sample by the volume obtained from the thickness and area of the sample. It was calculated using.
- the reflectivity of the sheet was measured using a reflectance spectrometer combining a spectrophotometer manufactured by JASCO Corporation and an integrating sphere sample table, using a reflection plate of a standard white plate of polytetrafluoroethylene (Spectralon manufactured by Labosphere). Measure the relative reflectance with a reflectance of 100% for light with a wavelength of 550 nm.
- Melt flow rate is based on the method described in JISK7210.
- Polypropylene resin has a temperature of 230 ° C and a load of 21.2N.
- Polycarbonate resin has a temperature of 300 ° C and a load of 11.8N. was measured under the conditions of a temperature of 200 ° C and a load of 49N.
- the reflecting sheet was cut in the direction perpendicular to the surface using a microtome or the like, the magnification was set in the range of 1,000 to 10,000, and an enlarged photograph of the cross section was taken using a scanning electron microscope.
- the magnification of the scanning electron microscope was set such that the resin (B) phase having a size of at least 0 was confirmed by observing the photograph with the naked eye.
- the maximum length in the plane direction was determined from the measured value of the length of the photographic image and the magnification of the photograph in units of 0 .: L m.
- Both the maximum length in the thickness direction and the maximum length in the plane direction of the resin (B) phase are 0.5 m or more.
- Select 50 resin (B) phases from the photograph The maximum length (X) and the maximum length (Z) in the thickness direction were recorded. Both the maximum length in the thickness direction and the maximum length in the plane direction are 0. If 50 resin (B) phases that are 5 m or longer cannot be found in one photo, take another image of the reflective sheet with a scanning electron microscope and measure 50 sets of X and Z values. I asked. From the obtained 50 sets of X and Z measurements, 50 XZZ values were calculated and the standard deviation values were increased.
- the drawn sheet was stretched at 155 ° C using a pantograph-type biaxial stretching machine manufactured by Iwamoto Seisakusho.
- the stretching speed was 10 mmZ seconds, and the film was stretched three times in the sheet extrusion direction and three times in the sheet width direction.
- the stretching stress per unit sectional area of the sheet calculated from the tension value measured per lcm width of the sheet and the thickness of the sheet before stretching measured by the tension gauge attached to the chuck of the stretching machine was 590 NZcm 2 at maximum.
- the sheet turned white by stretching, and the sheet after stretching had a thickness of 208 m, a porosity of 38%, and a reflectance of 96%.
- the point light source of the light emitting diode was irradiated, and it was recognized that the reflected light was diffused.
- melt flow rate as (A) is 0. 5GZ min 0/0, melt flow rate were mixed in a ratio of 5 g / 10 min Polycarbonate 20% by volume and (B) Using the same extruder and die as in Example 1, a sheet was formed from the raw materials under the same conditions. The sheet was stretched three times vertically and four times horizontally at a temperature of 153 ° C. The sheet turned white by stretching, and had a thickness of ⁇ m, a porosity of 33% and a reflectivity of 93%.
- the stretching tension was 420 NZcm 2 .
- the drawing tension was reduced to 71% of the stretching tension in Example 1 in which the polystyrene resin was not added.
- the sheet turned white by stretching, the thickness was 190 ⁇ m, the porosity was 36%, and the reflectance was 97%.
- a melt flow rate as (A) is a homo polypropylene 0. 5GZlO content of 48 vol 0/0, the raw materials mixed at a ratio melt flow rate of the polycarbonate 52 volume 0/0 5GZlO min as (B), performed An attempt was made to stretch the sheet by extruding it under the same equipment and conditions as in Example 1, but the sheet broke. Attempted stretching by raising the stretching temperature by 1 ° C, but failed to stretch due to breakage.When the temperature was raised to 160 ° C, the sheet melted. I could't help.
- volume homo polypropylene melt flow rate as (A) is 0. 5GZ min 0/0, (B) and to 38 to melt flow rate 5GZ content of polycarbonate volume 0/0, melt flow rate 1.
- 3GZlO The raw material obtained by mixing 10 parts by volume of polystyrene at a ratio of 10% by volume was formed into a sheet under the same conditions using the same extruder and die as in Example 1. The sheet was stretched three times vertically and three times horizontally at a temperature of 154 ° C.
- Table 1 shows the physical property values of the sheets obtained in Examples and Comparative Examples.
- Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 material polypropylene resin 52 volume% 80 volume% 52 volume% 48 volume% 82 volume 0/0 52 volume 0 /.
- Resin Poly force one Boneto ⁇ 48 volume% 20 volume% 43 volume% 52 volume% 18 volume 0/0 38 volume 0/0 polystyrene Kitsuki effect 5 volume% 10 volume% stretching temperature (V) 1 5 5 153 154 stretching Possible temperature 155 155 Stretching ratio 3 times X 3 times 3 times "times 3 times X 3 times 3 times ⁇ 3 times 3 times X 3 times Thickness ( ⁇ ) 208 190 190 None.
- the reflection sheet of the present invention can be suitably used as a reflection material used for a knock light or the like of a liquid crystal display device.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Nonlinear Science (AREA)
- Mathematical Physics (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Optical Elements Other Than Lenses (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2005800108119A CN1938614B (zh) | 2004-03-30 | 2005-03-30 | 反射板及其制备方法 |
US10/592,636 US20070206299A1 (en) | 2004-03-03 | 2005-03-30 | Reflective Sheet and Method for Producing Same |
JP2006511736A JPWO2005096036A1 (ja) | 2004-03-30 | 2005-03-30 | 反射シート及びその製造方法 |
EP05727589A EP1731930A1 (en) | 2004-03-30 | 2005-03-30 | Reflective sheet and method for producing same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2004099098 | 2004-03-30 | ||
JP2004-099098 | 2004-03-30 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2005096036A1 true WO2005096036A1 (ja) | 2005-10-13 |
Family
ID=35063924
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2005/006090 WO2005096036A1 (ja) | 2004-03-03 | 2005-03-30 | 反射シート及びその製造方法 |
Country Status (6)
Country | Link |
---|---|
US (1) | US20070206299A1 (ja) |
EP (1) | EP1731930A1 (ja) |
JP (1) | JPWO2005096036A1 (ja) |
KR (1) | KR100846336B1 (ja) |
CN (1) | CN1938614B (ja) |
WO (1) | WO2005096036A1 (ja) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008083257A (ja) * | 2006-09-26 | 2008-04-10 | Asahi Kasei Corp | 異方性反射フィルム |
JP2008081563A (ja) * | 2006-09-26 | 2008-04-10 | Asahi Kasei Corp | 光拡散反射シート |
JP2009014775A (ja) * | 2007-06-29 | 2009-01-22 | Asahi Kasei Corp | 反射シート |
JP2009265347A (ja) * | 2008-04-24 | 2009-11-12 | Panasonic Electric Works Co Ltd | 光反射シート |
JP2009276596A (ja) * | 2008-05-15 | 2009-11-26 | Toyobo Co Ltd | 光反射用積層フィルム |
JP2010039044A (ja) * | 2008-08-01 | 2010-02-18 | Toyobo Co Ltd | 光反射用積層体 |
US8358468B2 (en) | 2007-06-05 | 2013-01-22 | Asahi Kasei Kabushiki Kaisha | Reflecting sheet |
WO2013122025A1 (ja) * | 2012-02-13 | 2013-08-22 | 東レ株式会社 | 反射フィルム |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101955240B1 (ko) * | 2012-09-21 | 2019-03-08 | 도레이첨단소재 주식회사 | 액정디스플레이 백라이트유닛용 반사시트 및 그의 제조방법 |
WO2015005584A1 (ko) * | 2013-07-10 | 2015-01-15 | 한국생산기술연구원 | 섬유배향 복합재의 제조방법, 그로부터 제조된 섬유배향 복합재, 상기 섬유배향 복합재로 이루어진 반사편광필름 및 그 제조방법 |
JP6232486B2 (ja) * | 2016-01-19 | 2017-11-15 | 住友化学株式会社 | 光学積層体の製造方法 |
CN108761591B (zh) * | 2018-05-22 | 2021-08-24 | 四川京龙光电科技有限公司 | 一种用于侧入式背光模组的涂布型反射膜 |
CN109814187B (zh) * | 2019-03-22 | 2020-11-10 | 宁波东旭成新材料科技有限公司 | 一种光学反射膜 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002071921A (ja) * | 2000-08-31 | 2002-03-12 | Toyobo Co Ltd | 面光源用反射フィルム |
JP2003160682A (ja) * | 2001-11-27 | 2003-06-03 | Toray Ind Inc | 光反射フィルム |
JP2004070117A (ja) * | 2002-08-08 | 2004-03-04 | Toray Ind Inc | 光反射フィルム |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1287795C2 (de) * | 1963-03-02 | 1975-03-06 | Metal Containers Ltd., London | Geschichtetes thermoplastisches blattmaterial |
US5594062A (en) * | 1994-03-16 | 1997-01-14 | Kawasaki Steel Corporation | Polycarbonate/polyolefin based resin compositions and their production processes and uses |
US5645933A (en) * | 1994-04-22 | 1997-07-08 | Nippon Petrochemicals Company, Limited | Polypropylene monoaxially oriented material, woven or non-woven fabric, laminated product and preparation method |
US6497946B1 (en) * | 1997-10-24 | 2002-12-24 | 3M Innovative Properties Company | Diffuse reflective articles |
US6171689B1 (en) * | 1999-01-15 | 2001-01-09 | 3M Innovative Properties Company | Flame retardant microporous materials |
US7285327B2 (en) * | 2000-07-12 | 2007-10-23 | Toray Industries, Inc. | White film for surface light source reflecting members |
-
2005
- 2005-03-30 CN CN2005800108119A patent/CN1938614B/zh not_active Expired - Fee Related
- 2005-03-30 US US10/592,636 patent/US20070206299A1/en not_active Abandoned
- 2005-03-30 WO PCT/JP2005/006090 patent/WO2005096036A1/ja not_active Application Discontinuation
- 2005-03-30 JP JP2006511736A patent/JPWO2005096036A1/ja not_active Withdrawn
- 2005-03-30 KR KR1020067019993A patent/KR100846336B1/ko not_active IP Right Cessation
- 2005-03-30 EP EP05727589A patent/EP1731930A1/en not_active Withdrawn
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002071921A (ja) * | 2000-08-31 | 2002-03-12 | Toyobo Co Ltd | 面光源用反射フィルム |
JP2003160682A (ja) * | 2001-11-27 | 2003-06-03 | Toray Ind Inc | 光反射フィルム |
JP2004070117A (ja) * | 2002-08-08 | 2004-03-04 | Toray Ind Inc | 光反射フィルム |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008083257A (ja) * | 2006-09-26 | 2008-04-10 | Asahi Kasei Corp | 異方性反射フィルム |
JP2008081563A (ja) * | 2006-09-26 | 2008-04-10 | Asahi Kasei Corp | 光拡散反射シート |
US8358468B2 (en) | 2007-06-05 | 2013-01-22 | Asahi Kasei Kabushiki Kaisha | Reflecting sheet |
JP2009014775A (ja) * | 2007-06-29 | 2009-01-22 | Asahi Kasei Corp | 反射シート |
JP2009265347A (ja) * | 2008-04-24 | 2009-11-12 | Panasonic Electric Works Co Ltd | 光反射シート |
JP2009276596A (ja) * | 2008-05-15 | 2009-11-26 | Toyobo Co Ltd | 光反射用積層フィルム |
JP2010039044A (ja) * | 2008-08-01 | 2010-02-18 | Toyobo Co Ltd | 光反射用積層体 |
WO2013122025A1 (ja) * | 2012-02-13 | 2013-08-22 | 東レ株式会社 | 反射フィルム |
JPWO2013122025A1 (ja) * | 2012-02-13 | 2015-05-11 | 東レ株式会社 | 反射フィルム |
Also Published As
Publication number | Publication date |
---|---|
CN1938614A (zh) | 2007-03-28 |
US20070206299A1 (en) | 2007-09-06 |
KR100846336B1 (ko) | 2008-07-15 |
EP1731930A1 (en) | 2006-12-13 |
JPWO2005096036A1 (ja) | 2008-02-21 |
KR20060134128A (ko) | 2006-12-27 |
CN1938614B (zh) | 2010-05-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2005096036A1 (ja) | 反射シート及びその製造方法 | |
US7132136B2 (en) | Stacked microvoided light diffuser | |
US7327415B2 (en) | Microvoided light diffuser | |
US8434885B2 (en) | Reflecting sheet | |
TW200848797A (en) | Optical diffuser film and light assembly | |
JP2010015133A (ja) | 拡散に変化を持たせた線状ドメインを有する光拡散膜 | |
EP1873562A1 (en) | Reflective sheet and method for producing same | |
US8794798B2 (en) | White film and surface light source using same | |
WO2005116699A1 (ja) | 光反射体およびそれを用いた面光源装置 | |
JP2003248111A (ja) | 光ディフューザ | |
JP2003160682A (ja) | 光反射フィルム | |
JP2009036984A (ja) | 光拡散フィルムとその製造方法 | |
JP5141528B2 (ja) | 積層フィルムおよびこれを用いたバックライトユニット | |
JP2008158134A (ja) | 反射シート | |
JP2007140542A (ja) | 光反射フィルムとそれを用いた面光源 | |
JP2009186931A (ja) | 反射シート | |
JP6459950B2 (ja) | 反射フィルム、及びこれを備えてなる液晶表示装置、照明装置、装飾用物品 | |
JP2009109596A (ja) | 反射シート | |
JP2011069989A (ja) | 反射シート | |
JP2011069988A (ja) | 反射シート | |
JP2008158135A (ja) | 反射シートの製造方法 | |
JP2011069991A (ja) | 反射シート | |
KR101466346B1 (ko) | 저경도 백색 폴리에스테르 필름 | |
KR101610822B1 (ko) | 저광택 백색 폴리에스테르 필름과 이의 제조방법 및 이를 이용한 반사시트 | |
JP2009186930A (ja) | 反射シートの製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2006511736 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2005727589 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 10592636 Country of ref document: US Ref document number: 2007206299 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1020067019993 Country of ref document: KR |
|
WWE | Wipo information: entry into national phase |
Ref document number: 200580010811.9 Country of ref document: CN |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: DE |
|
WWP | Wipo information: published in national office |
Ref document number: 2005727589 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1020067019993 Country of ref document: KR |
|
WWP | Wipo information: published in national office |
Ref document number: 10592636 Country of ref document: US |