WO2008053740A1

WO2008053740A1 - White polyester film for liquid crystal display reflector

Info

Publication number: WO2008053740A1
Application number: PCT/JP2007/070583
Authority: WO
Inventors: Masahiro Okuda; Hideki Fujii; Kazunori Tanaka
Original assignee: Toray Industries, Inc.
Priority date: 2006-10-27
Filing date: 2007-10-23
Publication date: 2008-05-08
Also published as: CN101512394A; KR20090073054A; TW200829963A; CN101512394B; JPWO2008053740A1; KR101186833B1; JP5526477B2; TWI460477B

Abstract

[PROBLEMS] To improve not only the durability of a reflecting film but also that of a peripheral member, and to reduce manufacture loss by preventing adhesion of fine foreign materials such as dusts. [MEANS FOR SOLVING PROBLEMS] Provided is a white polyester film for liquid crystal display reflectors, which contains a light stabilizer in a polyester film having fine air bubbles and has an average reflectivity of 97% or more on the surface of at least one side of the film.

Description

Specification

White polyester film for LCD reflector

Technical field

[0001] The present invention relates to a white polyester film, and more particularly to a white polyester film that is optimal as a reflector for a liquid crystal display. More specifically, a brighter screen can be obtained by illuminating the LCD screen with a sidelight (also called edge light) or by arranging a fluorescent tube directly above the reflective film (called a direct type). The present invention relates to a white polyester film for a display reflector that can constitute a substrate for a reflector.

Background art

In recent years, many displays using liquid crystals have been used as display devices for personal computers, televisions, mobile phones and the like. Conventionally, when illuminating these liquid crystal displays, the backlight system that shines light from the back of the display, or the sidelight system power as shown in Patent Document 1! Widely used. The sidelight system is a system in which a transparent substrate such as an acrylic plate with a certain thickness is subjected to various treatments such as halftone dot printing and embossing, and light from a cold cathode tube is applied to the edge of the acrylic plate. Illumination light is evenly distributed, and a screen with uniform brightness is obtained. In addition, since the lighting is installed at the edge portion connecting the back of the screen, it can be made thinner than the backlight method. In order to prevent the illumination light from escaping from the back of the screen, it is necessary to install a reflector on the back of the screen. However, since this reflector is required to be thin and highly reflective, it is necessary to use a film. A white film or the like that is whitened by containing fine bubbles inside and scattering light by the bubbles is mainly used.

On the other hand, for large screens such as liquid crystal televisions, a direct light system has been adopted.

In this system, cold cathode ray tubes are arranged in parallel at the bottom of the liquid crystal screen. The reflector may be a flat plate or a cold cathode ray tube formed into a semicircular concave shape. Conventionally, a film added with a white pigment, a film containing fine bubbles inside, or a film obtained by bonding these films to a metal plate, a plastic plate, or the like has been used. Improved brightness, especially when using a film containing fine bubbles inside Excellent effect and uniformity (Patent Document 2)

[0004] The formation of such fine bubbles is achieved by dispersing inorganic particles such as a high melting point incompatible polymer or barium sulfate in a film base material such as polyester and stretching it (for example, biaxially). This is achieved by stretching. During stretching, voids (bubbles) are formed around the incompatible polymer particles, which exert a scattering action on the light, so that it is whitened and a high reflectivity can be obtained.

[0005] Furthermore, the technique of Patent Document 2 aims to ensure the reflectance of light having a wavelength of 400 to 700 nm and to improve the reflectance of light having a wavelength of less than 400 nm, and the cavity-containing film contains a fluorescent brightening agent. Take the structure to make it happen.

[0006] In recent years, display devices such as liquid crystal display panels are also required to have an unprecedented advanced display capability for displaying photographic images and moving images. There is an increasing demand for higher performance such as improvement of color and white reproducibility. In order to meet these demands, the demands for ultraviolet absorption and various durability required for reflectors are further increasing.

[0007] For example, there is a particular demand for characteristics that can suppress deterioration even after long-term use and can be used stably. Therefore, for example, Patent Document 3 discloses a void-containing polyester film containing a light stabilizer in order to ensure stability.

[0008] In general, the biaxially stretched polyester film has a problem in that dust is attached to the film during the film forming process, the heating process and the use as soon as static electricity is generated. In recent years, as the size of the screen increases, the dust greatly affects the manufacturing loss. Therefore, there is an increasing demand for antifouling properties for each member during the liquid crystal monitor manufacturing process in which the polyester film is used. . From this demand, Patent Document 4 obtains an antifouling effect by imparting antistatic properties to the film. However, the film provided in Patent Document 4 cannot be applied to a liquid crystal display device that requires light stability, and an optical film having both light stability and antifouling properties is required.

Patent Document 1: JP 63 62104 A

Patent Document 2: Japanese Patent Laid-Open No. 239540

Patent Document 3: Japanese Patent Laid-Open No. 2002-098808 Patent Document 4: JP-A-10-278204

Disclosure of the invention

Problems to be solved by the invention

However, in the conventional technique, the deterioration of the member is promoted by the ultraviolet rays emitted from the fluorescent tube, and in the long-term use, the temperature and humidity conditions in the liquid crystal unit and the like are greatly changed. Due to the difference in rate, the members may be distorted. At this time, if the contact area of the members is large, the members are rubbed with each other when distortion occurs. When this squeak is repeated, deterioration of the member is promoted, and the characteristics deteriorate from scratches caused by rubbing. Moreover, the loss due to the adhesion of dust in the manufacturing and assembly process is also large. If these problems are solved simply by adding a light stabilizer that imparts light stability, adding particles for making irregularities, and adding an antistatic agent, only optical properties will deteriorate due to coloring and scattering. There is a concern that a reaction will occur between each material and the performance of each material will be canceled.

Means for solving the problem

In order to solve the problem, the present invention has the following configuration. That is,

(1) A white polyester film for a liquid crystal display reflector, which contains a light stabilizer in a polyester film having fine bubbles and has an average reflectance of 97% or more on at least one surface of the film.

(2) The liquid crystal according to (1), wherein the polyester film (A) has a structure in which a polyester layer (B) containing a light stabilizer is laminated on at least one side of the polyester layer (A) having fine bubbles. White polyester film for display reflectors.

(3) A layer (C) containing an antistatic agent is applied to at least one surface of the polyester film, and the surface specific resistance value of the layer (C) is IX 10 ¹³ Ω / mouth or less (1) or ( The polyester film for a liquid crystal display reflector as described in 2).

(4) The liquid crystal display reflection according to any one of (1) to (3), wherein the center plane average roughness Ra of the polyester film surface is 0.1 or more and a ten-point average roughness Rz is 1.0 or more White polyester film for board.

(5) Content strength of light stabilizer contained in the polyester film The white polyester film for a liquid crystal display reflector according to any one of (1) to (4), wherein the content is from 0.2% to 20% by weight based on the total weight of the rumm.

(6) The white polyester film for a liquid crystal display reflector according to any one of (1) to (5), which is a light stabilizer of a malonate ester, contained in the polyester film. .

(7) The liquid crystal display reflector according to any one of (1) to (6), which is a light stabilizer strength S, 2,6-naphthalenedicarboxylic acid or a copolymer thereof contained in the polyester film. White polyester film.

(8) The polyester film contains titanium dioxide particles, and the content thereof is 1% by weight or more and 40% by weight or less based on the total weight of the polyester film.

V, a white polyester film for a liquid crystal display reflector according to any one of the above.

(9) The polyester film contains particles having an average particle size of 1. O ^ m or more (hereinafter referred to as large particle size particles), and the content thereof is 0.01% by weight with respect to the total weight of the polyester film. The white polyester film for a liquid crystal display reflector according to any one of (1) to (8), wherein the content is 5% by weight or less.

(10) The polyester film for a liquid crystal display reflector according to (9), wherein the large-diameter particles are silica particles.

(11) The white polyester for a liquid crystal display reflecting plate according to any one of (1) to (10), wherein the polyester film contains a thermoplastic resin incompatible with the polyester to form fine bubbles. the film.

(12) The polyester resin incompatible with the polyester is polymethylpentene, the average particle size in the polyester film is equal to or less than the average particle size of the large particles, and the total weight of the polyester film The white polyester film for a liquid crystal display reflector as described in (11), which is contained in an amount of 5% by weight to 25% by weight.

(13) The white polyester film for a liquid crystal display reflector according to any one of (1) to (12), wherein the specific gravity of the polyester film is 0.5 or more and 1.2 or less.

(14) The white polyester for a liquid crystal display reflector according to any one of (1) to (13), wherein fine bubbles are formed when the polyester film contains inorganic particles. Tell film.

(15) The inorganic particles contained to form the fine bubbles are barium sulfate, and the barium sulfate has an average particle size of 0.1, 1 m or more, 5.0, 1 m or less, and a large particle size The white polyester film for a liquid crystal display reflector according to (14), which is not more than the average particle diameter of the particles and contains 5 to 70% by weight based on the total weight of the polyester film.

(16) The white polyester film for a liquid crystal display reflector according to any one of (1) to (15), wherein the specific gravity of the polyester film is 1.2 or more and 1.4 or less.

(17) The polyester film according to any one of (2) to (16), wherein the core layer portion is the polyester layer (A) and one or both surface layer portions are the polyester layer (B). White polyester film for liquid crystal display reflectors.

The invention's effect

[0011] According to the present invention, it is possible to obtain a white polyester film for a liquid crystal display reflecting plate having both light stability, antifouling property and low rubbing property. Thereby, the polyester film and other components incorporated in the liquid crystal panel can be obtained. As a result, the durability of the peripheral members can be improved, and the production loss due to adhesion of foreign matters can be reduced.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

[0013] [Layer structure]

The polyester film of the present invention needs to contain a light stabilizer in the polyester film having fine bubbles.

[0014] The polyester film of the present invention may be either a single layer or a multilayer.

It is a laminated structure using (A) and (B), the polyester layer (A) is a layer containing fine bubbles, and the polyester layer (B) is a layer containing a light stabilizer on at least one side thereof. Is preferable in terms of high reflectivity, film-forming properties, optical properties, and light stability.

[0015] The polyester film of the present invention preferably has a structure in which the polyester layer (B) containing a light stabilizer is laminated on at least one side of the polyester layer (A) having fine bubbles. ! /, (This stacking mode is hereinafter referred to as “mode 1”).

[0016] A layer containing an antistatic layer on at least one side of the polyester film of the present invention ( c)

It is also preferable to provide it.

[0017] The polyester film of the present invention may be composed of a number of layers as long as it includes the structure of the polyester layer (A) and the polyester layer (B). For example, a polyester layer (B) / polyester layer (A) / polyester layer (B), or a polyester layer (A) / polyester layer (B) or a polyester layer (B) A) / Polyester layer (B) / Polyester layer (A) / Polyester layer (B). Further, it may have a structure of five layers or more. By using a multi-layer structure, the characteristics of each layer are expressed on the surface of the laminated polyester film, and the ability S to control various characteristics can be achieved.

[0018] Considering the ease and effect of film formation, a two-layer structure or a three-layer structure comprising a polyester layer (B) / polyester layer (A) / polyester layer (B) is preferred! /. In particular, a form in which the polyester layer (B) is protected by the polyester layer (B), that is, a three-layer structure of polyester layer (B) / polyester layer (A) / polyester layer (B) is preferable. Further, it is preferable that the core layer portion is a polyester layer (A) and the surface layer portion on one or both sides is a polyester layer (B).

[0019] [Polyester film]

The polyester constituting the present invention is a polymer obtained by condensation polymerization from a diol and a dicarboxylic acid. Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, adipic acid, sebacic acid, and the like. The diol is represented by ethylene glycol, trimethylene glycol, tetramethylene glycol, cyclohexane dimethanol and the like. Specific examples include polymethylene terephthalate, polytetramethylene terephthalate, polyethylene p-oxybenzoate, poly 1,4-cyclohexylene dimethylene terephthalate, polyethylene 2,6-naphthalenedicarboxylate, and the like. In the present invention, polyethylene terephthalate (hereinafter sometimes abbreviated as PET) and polyethylene naphthalate are particularly preferable.

[0020] Further, in this polyester, various known additives such as antioxidants, An inhibitor or the like may be added. The polyester used in the present invention is preferably polyethylene terephthalate. Polyethylene terephthalate film has excellent water resistance, durability and chemical resistance.

[0021] When polyethylene terephthalate is used as a basic component, from the viewpoint of film formation stability, it is preferably 1 mol% or more and 15 mol% or less, more preferably 3 mol% or more and 14 mol% or less, and most preferably, based on the total dicarboxylic acid component. It is preferable to use a copolyester containing 5 to 13 mol% of a copolysynthetic component. If it is less than 1 mol%, a layer containing inert particles, for example, containing 31% by weight or more of barium sulfate or titanium dioxide particles may not be able to form a film. Even more than 15 mol%, in some cases force ^s impossible film.

[0022] Examples of the copolymer component include dicarboxylic acid components such as isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, adipic acid, sebacic acid, phthalic acid, 5 — Sodium sulfoisophthalic acid. Examples of the diol include ethylene glycol, 1,4 butanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, neopentyl glycol, and polyalkylene glycol. In particular, it is preferable to use isophthalic acid or 2,6-naphthalenedicarboxylic acid as a copolymerization component of the polyester used for the polyester layer (A) in order to obtain good film forming properties.

[0023] [Formation of fine bubbles]

In the present invention, the average reflectance in the wavelength range of 400 to 700 nm needs to be 97% or more on at least one side of the film. This is because if it is less than 97%, the brightness of the reverse prism type backlight may be lowered. In the present invention, the average reflectance is the reflectance when an integrating sphere is attached to a Hitachi High-Technologies spectrophotometer (U-3310) and the standard white plate (aluminum oxide) is 100%. Measured from 400 to 700 nm, read the reflectance from the obtained chart at intervals of 5 nm, and averaged the values.

[0024] In order to achieve a reflectance of 97% or more, it is important that the film is whitened by containing fine bubbles and inert inorganic particles, thereby exhibiting a light scattering effect. Therefore, the reflectance can be improved. Preferably, the reflectivity is 98% or more, more preferably 100% or more. There is no particular upper limit on the reflectivity, but in order to increase the reflectivity, it is necessary to increase the amount of added calories of the incompatible thermoplastic resin or inorganic particles used as the bubble-forming nucleating agent. 110% or less is preferable since the property may become unstable.

[0025] Formation of fine bubbles is achieved by dispersing a high-melting-point polyester or an incompatible thermoplastic resin or inorganic particles in a film base material such as polyester, and stretching it (for example, biaxially). This is achieved by stretching. During stretching, voids (bubbles) are formed around the incompatible thermoplastic resin or inorganic particles, which exerts a scattering action on light, so that it becomes white and high reflectivity can be obtained. Incompatible thermoplastic resins and inorganic particles suitable in the present invention will be described later.

[0026] [Large particle size particles]

Further, in the present invention, it is preferable that the center surface average roughness Ra of the film surface is 0.1 or more, and the force and ten-point average roughness Rz is 1.0 or more. More preferably, Ra is 0.1 or more and less than 1.0 and Rz is 1.0 or more and less than 10.0, and more preferably Ra is 0.1 or more and less than 0.4 and Rz is 1.0 or more 6. Is less than 0. The Ra and Rz values are related to the deterioration of the film surface due to friction between members. By providing minute irregularities on the surface of the member, rubbing can be reduced and stability can be improved. If Ra is less than 0.1 and Rz is less than 1.0, the difference in coefficient of thermal expansion between the components will be different when placed in an environment where the temperature and humidity conditions change greatly, assuming long-term use. Therefore, the force that causes the problem of distortion of the member is generated. This repetition promotes the deterioration of the member. When Ra is 0.4 or more, or R z is 6.0 or more, the scattering effect due to surface roughness becomes strong and the optical characteristics may be deteriorated.

[0027] In order to achieve the above Ra and Rz, the polyester film of the present invention preferably contains a large particle size particle. When the polyester film of the present invention has a polyester layer (A) and a polyester layer (B), the polyester layer (A) and / or the polyester layer (B)

It is preferable to contain large particles. [0028] Further, the large particle diameter particles have the largest average particle diameter (average particle diameter refers to the number average particle diameter. The same applies in the present specification) among the particles contained in the film. Refers to large particles.

[0029] The type of particles used as the large particle size particles is not limited! /, But in order to obtain stable film-forming properties and high optical properties, the inorganic particles include silica particles, titanium dioxide particles, Acrylic particles and the like are preferable as the organic particles that are preferred to be barium sulfate particles, aluminum oxide particles, and the like. In addition, they can be used alone or in combination of two or more. Among them, silica particles are particularly preferred from the viewpoint of dispersion diameter stability of the particles and film formation stability.

[0030] The average particle size of the large particles is preferably 1 · 0 m or more, more preferably 1 · O ^ m or more and 5 111 or less, and further preferably 3 m or more and 5 m or less.

[0031] Further, the content of the large particle size is preferably 0.01 wt% or more and 5.0 wt% or less, more preferably 0.01 wt% when the total weight of the polyester film is 100 wt%. % To 1.0% by weight, more preferably 0.01% to 0.5% by weight.

[0032] When the polyester film of the present invention adopts embodiment 1, it is preferable that the polyester layer (A) and / or the polyester layer (B) contain large particle diameter particles, more preferably polyester. The layer (B) contains a large particle size particle.

[0033] When the polyester layer (B) contains large particles, the average particle size of the large particles is preferably 1 am or more, more preferably 1 μm or more and 5, im or less, and even more preferably 3 μm or more and 5 111 or less. Further, the content is preferably 0.01-5M% by weight based on the total weight of the polyester layer (B), more preferably 0.01 ~; More preferably, the content is 0.01 to 0.5% by weight.

[0034] When the average particle size of the large particle size is less than 1 μm, it is necessary to increase the content very much in order to increase Ra to 0.1 or more, resulting in light scattering by the particle. It has the power to cause deterioration of optical characteristics. Further, when the average particle size is 5 m or more, surface irregularities can be obtained, but light scattering by the large particle size particles becomes large, and optical characteristics may be deteriorated. Moreover, the film forming property may be deteriorated.

[0035] When the content of the large particle size is 0.01% by weight or less, the surface roughness is small. And Rz value may decrease. For this reason, there is a force S that causes friction between members and promotes deterioration of the member. If the silica particles are 5% by weight or more, the optical properties may be deteriorated due to the scattering caused by the excessive silica particles.

[0036] [Polyester incompatible with polyester]

The polyester film of the present invention is required to have fine bubbles inside the polyester film. As described above, the polyester film contains a thermoplastic resin that is incompatible with polyester, thereby forming fine bubbles. be able to.

[0037] As a resin suitable as an incompatible thermoplastic resin, for example, poly 3 methyl phthalene is used.

1, poly-4-methylpentene 1, polybutyl t-butane, 1,4 trans poly 2,3 dimethyl butadiene, polybutyl cyclohexane, polystyrene, polymethyl styrene, polydimethyl styrene, polyfluoro styrene, poly 2 methyl-4 fluoro styrene, Examples thereof include polymers having a melting point of 200 ° C. or higher selected from polyvinylino tert-butylenoate triole, cenololenoretriacetate, cenorenoretripropionate, polybulufluoride, polychlorofluoroethylene and the like. Among them, polyolefin, particularly polymethylpentene is preferable for the polyester base material.

[0038] The addition amount of the incompatible thermoplastic resin is preferably 5% by weight or more and 25% by weight or less when the total weight of the entire polyester film is 100% by weight.

[0039] Further, when the polyester film of the present invention adopts embodiment 1, it is more preferable that the polyester layer (A) and / or the polyester layer (B) contain an incompatible thermoplastic resin. Is to contain an incompatible thermoplastic resin in the polyester layer (A). When the incompatible thermoplastic resin is contained in the polyester layer (A), the content is preferably 5% by weight or more and 25% by weight or less based on the total weight of the polyester layer (A). 10% by weight or more and 25% by weight or less.

[0040] If the content is less than this, the effect of whitening is diminished and it is difficult to obtain a high reflectance, and if it is too high, mechanical properties such as strength of the film itself may be too low.

[0041] It is preferable that the incompatible thermoplastic resin is uniformly dispersed. Due to the uniform dispersion, bubbles are uniformly formed inside the film, and the degree of whitening and thus the reflectance becomes uniform. In order to uniformly disperse the incompatible thermoplastic resin, a low specific gravity agent is added as a dispersion aid. It is effective to add. A low specific gravity agent is a compound having an effect of reducing the specific gravity, and the effect is recognized in a specific compound. For example, for polyester, polyalkylene glycols such as polyethylene glycol, methoxypolyethylene glycol, polytetramethylene glycol, polypropylene glycol, ethylenoxide / propylenoxide copolymer, sodium dodecylbenzenesulfonate, sodium alkylsulfonate , Glycerol monostearate, tetrabutylphosphonium paraamino benzenesulfonate and the like. In the present invention, polyalkylene glycol, particularly polyethylene glycol is particularly preferred. A copolymer of polybutylene terephthalate and polytetramethylene glycol is also preferably used for improving the dispersibility of the incompatible thermoplastic resin. The amount added is preferably 3% by weight or more and 20% by weight or less, particularly preferably 10% by weight or more and 25% by weight or less, based on the total weight of the polyester film. When the polyester film of the present invention adopts embodiment 1 and the polyester layer (A) contains an incompatible thermoplastic resin, the amount of the low specific gravity agent added is relative to the total weight of the polyester layer (A). 3 to 25% by weight is preferable, and 10 to 20% by weight is particularly preferable. If the amount of the low specific gravity agent is too small, the effect of the addition is diminished, and if it is too large, the original properties of the film base material may be impaired. Such a low specific gravity agent can be added in advance to the film base polymer and adjusted as a master polymer (master chip).

[0042] By including fine bubbles in the white polyester film using an incompatible thermoplastic resin, the apparent specific gravity of the polyester film becomes lower than that of a normal polyester film. If a lower specific gravity agent is further added, the specific gravity is further lowered. In other words, a white and light film can be obtained. In order to reduce the weight of this white polyester film while maintaining the mechanical properties as a substrate for a liquid crystal display reflector, the specific gravity is preferably 0.5 or more and 1.2 or less.

[0043] In order to set the specific gravity to 0.5 or more and 1.2 or less, when a low specific gravity agent, for example, polymethylpentene having a specific gravity of 0.83 is used as described above, 5 to 25 with respect to the entire polyester film. Achievable force by adding less than or equal to weight% and setting the draw ratio to 2.5 to 4.5. In particular, when the polyester film of the present invention adopts embodiment 1, the apparent specific gravity is that of the present invention. If it is within the range, many fine bubbles can be present while maintaining the film strength, and a high reflectance can be obtained. That is, when it is used as a liquid crystal display reflector, the brightness of the screen is remarkably excellent.

[0044] Further, the specific gravity of the white polyester film for a liquid crystal display reflector of the present invention is 0.5 or more and 1.2 or less, preferably 0.5 or more and 1.0 when an incompatible thermoplastic resin is used. In the following, a force of 0.55 or more and 0.8 or less is preferable in order to obtain higher reflectivity.

[0045] The average particle size of the incompatible thermoplastic resin contained in the polyester film is equal to or less than the average particle size of the large particle size (less than 1.0 m in case of large particle size). Force S is preferred. More preferably, it is not more than the average particle size of the large particle size and not less than 0.2 111 and not more than 5 111, and more preferably not more than the average particle size of the large particle size particle and not less than 0.3 111 and not more than 3 111. Incompatible thermoplastic resin may correspond to large particle size, but in this case, the average particle size of the large particle size and the average particle size of the incompatible thermoplastic resin are the same. . In addition, when no large particle size particles are added to the polyester film, the average particle size of the incompatible thermoplastic resin is not particularly limited, but is preferably 0 • 2 μm or more and 1 μm. m, more preferably, 0.3 m or more and less than 1 μm.

[0046] When the particle diameter of the incompatible thermoplastic resin is smaller than the above range V, fine bubbles having the incompatible thermoplastic resin as a core are not formed, which is not preferable. On the other hand, if it is larger than the above range, the bubble size becomes large, which is not preferable because the film strength and film forming stability are lowered.

[0047] [Inorganic particles forming fine bubbles]

In the present invention, one of the preferred embodiments is the ability to suitably use the incompatible thermoplastic resin described above to form fine bubbles, and the use of inorganic particles to form fine bubbles. is there.

[0048] When inorganic particles are used, in order to obtain high optical properties and stable film forming properties, titanium dioxide, barium sulfate, calcium sulfate, magnesium sulfate, aluminum oxide, zinc oxide, magnesium oxide are used as the particle types. Calcium carbonate, barium carbonate, silica and the like are preferable. In addition, they can be used alone or in combination of two or more, Of these, barium sulfate particles and titanium dioxide particles are particularly preferred because high optical properties and film-forming stability can be obtained.

[0049] In addition, the above-described large particle size particles can also be used as inorganic particles that form fine bubbles within a range that does not impair optical properties!

[0050] [Barium sulfate particles]

When barium sulfate is used as the inorganic particles for forming fine bubbles, it is preferable that the barium sulfate particles are contained in an amount of 5 wt% to 70 wt% with respect to the total weight of the polyester film. More preferably, it is 10 wt% or more and 55 wt% or less, and further preferably 10 wt% or more and 50 wt% or less.

[0051] When the polyester film of the present invention has a polyester layer (A), it may contain 21 wt% or more and 70 wt% or less of barium sulfate particles based on the total weight of the polyester layer (A). preferable. More preferably, they are 23 weight% or more and 55 weight% or less, More preferably, they are 25 weight% or more and 50 weight% or less.

[0052] When the polyester film of the present invention has a polyester layer (B), it contains 0.1 to 15% by weight of barium sulfate particles with respect to the total weight of the polyester layer (B). It is preferable. More preferably, it is 0.2 to 14% by weight, and further preferably 0.5 to 13% by weight.

[0053] If the content is less than the lower limit of this range, the light scattered by the barium sulfate particles is insufficient, and sufficient reflection performance cannot be obtained. If the amount is larger than the upper limit of this range, the film-forming stability may be significantly lowered.

[0054] Further, the average particle diameter of barium sulfate contained in the polyester film is equal to or less than the average particle diameter (less than 1 · O ^ m in the case where there is no large particle size), and from 0 · 111 to 10 111 Preferably it is below. More preferably, it is not more than the average particle size of the large particle size and not less than 0.3 111 and not more than 8 111, and more preferably not more than the average particle size of the large particle size particle and not less than 0.5 m and not more than 5 m. By using barium sulfate having an average particle diameter in this range, good dispersibility and film forming stability can be obtained. The barium sulfate may be plate-shaped or spherical.

[0055] It should be noted that the force in which the barium sulfate particles may correspond to the large particle size particles, in this case, the large particle size The average particle size of the particles and the average particle size of the barium sulfate thermoplastic resin are the same.

[0056] When no large particle size is added to the polyester film, the average particle size of barium sulfate is preferably 0.1 m or more and less than 1 m, more preferably 0.3 μm. Or more and less than 1 μm, and more preferably from 0.δ μm to less than 1 μm.

[0057] By including fine bubbles in the white polyester film using such inorganic particles, the apparent specific gravity of the polyester film becomes lower than that of a normal polyester film. When bubbles are included using inorganic particles such as barium sulfate, an apparent specific gravity of 1.2 or higher is required to satisfy the optical characteristics while maintaining the mechanical characteristics of the substrate for the liquid crystal display reflector. More preferably, it is preferably 4 or less, but preferably 1.2 or more and 1.35 or less in order to obtain a higher reflectance. When the apparent specific gravity is within the range of the present invention, a large number of fine bubbles can be present while maintaining the film strength, and a high reflectivity can be obtained. In other words, when used as a liquid crystal display reflector, the brightness of the screen is remarkably excellent.

[0058] [Particle blending method]

Various methods can be used as a method of blending inorganic particles such as barium sulfate particles and rutile-type titanium dioxide into the polyester composition. The following method can be mentioned as the typical method. (A) A method of adding particles before transesterification reaction or esterification reaction at the time of polyester synthesis, or a method of adding particles before the start of polycondensation reaction. (I) A method in which particles are added to polyester and melt kneaded. (U) In the method of (a) or (i) above, manufacture master pellets with a large amount of particles added, and knead them with polyester without additives to contain a predetermined amount of additives. Method. (E) A method of using the master pellet of (u) as it is.

[0059] As a method of blending incompatible thermoplastic resin and barium sulfate particles, it is particularly preferable to take the above method (u) or (e) from the viewpoint of dispersibility of the particles.

[0060] The incompatible thermoplastic resin and barium sulfate particles have an average aperture of 10 to 100 m, preferably an average aperture of 15 to 15 made of a fine stainless steel wire having a wire diameter of 20 am or less as a filter during film formation. It is preferable to filter the molten polymer just before being extruded from the die using a 50 111 non-woven filter. By doing this, the number of coarse agglomerated particles can be reduced. Can do.

[0061] [Light stabilizer]

The white polyester film of the present invention is exposed to UV light derived from outside during storage, and is exposed to UV light from the fluorescent tube attached to the backlight unit during use, so the use of a light stabilizer is necessary. It is.

In the present invention, the polyester layer (B) preferably has a light stabilizer. It should be noted that the polyester layer (A) may contain a light stabilizer as long as the characteristics are not impaired. The content of the light stabilizer is preferably 0.02 wt% or more and 20 wt% or less, more preferably 0.1 wt% or more and 15 wt% or less, based on the total weight of the entire polyester film, Most preferably, it is 0.5 wt% or more and 15 wt% or less.

[0063] Further, when the polyester film of the present invention adopts embodiment 1, it is preferable that a predetermined amount of light stabilizer is contained in the polyester layer (B). The content of the light stabilizer in the polyester layer (B) is preferably 0.5 to 20% by weight, more preferably 0.5 to the total weight of the polyester layer (B). Most preferably, it is 15% by weight, more preferably 1-5% by weight.

[0064] When the content of the light stabilizer is less than 0.1% by weight, the light resistance is insufficient, and the film deteriorates during use for a long time, and its reflection characteristics are likely to be lowered. There's a problem. On the other hand, if it exceeds 20% by weight, the reflection characteristics may be deteriorated by coloring with a light stabilizer, which is not preferable.

[0065] The polyester film for a liquid crystal display reflector may be subjected to a heat step in a post-processing step such as coating, drying, and vapor deposition after film formation. Furthermore, the light stabilizer used in the present invention is excellent in heat resistance because it is a film that directly receives heat from the fluorescent tube attached to the backlight unit after installation and can withstand long-term storage in a roll state. It is desirable to select those that have good compatibility with the above-mentioned polyester and can be uniformly dispersed, and that are less colored and do not adversely affect the reflection characteristics of the resin and film. It is not particularly limited as long as it is a light stabilizer that satisfies the above conditions. For example, salicylic acid-based, benzophenone-based, benzotriazole-based, cyanoacrylate-based, triazine-based, malonic ester-based ultraviolet absorbers, hindered amine-based, etc. Near the visible light range, even when various kinds of dicarboxylic acid components with light stability such as UV stabilizers and naphthalenedicarboxylic acid are applicable. Especially preferred are malonic acid esters and naphthalenedicarboxylic acids, which have excellent color tone because they do not have an absorption peak in the long wavelength region near 350 nm. More specific application examples are as follows.

(UV absorber)

Malonic acid ester series: tetraethyl-2,2 '-(1,4 phenylene-dimethylidene) bis malonate, malonic acid [(4-methoxyphenyl) -methylene] -dimethyl ester salicylic acid series: p-t butylphenyl salicylate , P octylphenyl salicylate benzophenone series: 2, 4 dihydroxybenzophenone, 2 hydroxy 1-4 methoxy benzophenone, 2 hydroxy 1 4 methoxy 1 5 sulfobenzophenone, 2, 2, 1 4, 4'-tetrahydroxybenzo Phenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2, -dihydroxy 4,4'-dimethoxybenzophenone, bis (2 methoxy-4-hydroxy-5-benzoylphenol) methane

Benzotriazole series: 2— (2′-hydroxy 5 ′ methylphenol) benzotriazole, 2— (2′—hydroxy mono 5′—butyl phenol) benzotriazole, 2— (2′—hydroxy 3 ′, 5 ,-Tert-butylphenol) benzotriazole, 2- (2'-hydroxy 3'-t-butyl 5'-methylphenol) 1-5 clobenbenzotriazole, 2- (2'-hydroxy-3 ' , 5, 1-di-t-methylphenyl) 1-5-clobenzobenzolazole, 2- (2'-hydroxy-3-, 5-, 1-di-t-butylphenyl) 1-5-clobenzobenzolazole, 2- (2, -Hydroxy 5'-t octylpheninole) benzotriazole, 2- (2'-Hydroxy-3,5,1-di-tert-amylphenyl) benzotriazole, 2,2, methylenebis [4- (1, 1 , 3, 3 Tetramethylbutyl) -6— (2H Benzo Liazol-2-inole) phenol], 2 (2, Hydroxy-5, monomethataryloxyphenyl) 2H Benzotriazole, 2 -— [2, -Hydroxy-3,1- (3 ", 4", 5 ", 6" -tetrahydrophthalimide Methyl) 5'methylphenyl] benzotriazole

Cyanoacrylates: Ethyl-2 Cyanol 3, 3, -Diphenyl atylates Triazines: 2— (2,4 Dihydroxyphenyl) 1,4,6 Bis (2,4 dimethylphenyl) 1,3,3 5 Triazine, 2, 4 Bis [2 Hydroxy 4-butoxyphenyl] — 6 — (2, 4 Dibutoxyphenyl) 1 1, 3, 5 Triazine Other than the above: 2 Ethoxy 2'-Ethyloxazac acid bisanilide, 2— (4, 6 diphenol 1 1, 3, 5 Triazine 1 2 yl) 5— [(Hexyl) oxy] —Phenol, 2- (4,6 bis (2,4 dimethylphenyl) -1,3,5 triazine-1,2) 5-hydroxyphenyl, 2-ethyl, 2,1 ethoxyxarulanilide.

[0067] (UV stabilizer)

Hindered amines: bis (2, 2, 6, 6 tetramethyl-4-piperidyl) sepacate, dimethyl succinate 1-1 (2-hydroxyethyl) -4-hydroxy 2, 2, 6, 6 tetramethylbiperidine polycondensate

Other than the above: Nickel bis (octylphenyl) sulfide, [2 thiobis (4 t octyl phenolate)]-n butylamine nickel, nickel complex 3,5-zyb tertinore 4-hydroxybenzinorephosphate monoethylate, dickenore dibutinoresi O carbamate, 2, 4 g t-butylphenol 3, 5, 5, di-tert butyl oleate 4, hydroxy dibenzoate, 2, 4 g t-butyl feline, 3 ', 5'-di-tert-butyl- 4, monohydroxybenzoate 2, 2, 4, 4 Tetramethyl-7-oxy 3,20 diazo dipiro [5, 1, 11, 2] -heneicosan 21-one, 2, 2, 4, 4 Tetramethyl —21 oxo 7-oxy 3, 20 Diazodispiro [5. 1. 11. 2] Henicosan 20 Propionic acid dodecyl ester / tetradecyl ester, 2, 2, 4, 4 Tetramethyl-7 3, 20, diazo 20 (2, 3 epoxy propyl) dyspiro [5.1.1.2] —heneicosane 21—one polymer, propanetic acid, [(4 —methoxyphenyl) monomethylene] —, Bis (1, 2, 2, 6, 6 pentamethyl-4-piperidinyl) ester, 2, 6 naphthalene dicarboxylic acid.

[0068] Among these light stabilizers, tetraethyl-2,2'-one (1,4 phenylene-dimethylidene) bismalonate, malonic acid [(4-methoxyphenol) -methylene], which is excellent in compatibility with polyester Dimethyl ester, 2, 2,1,4,4 'tetrahydroxybenzophenone, bis (2 methoxy-1,4 hydroxy-1,5 benzoylphenol) methane, 2,2'-methylene bis [4- (1, 1, 3, 3, 3 Tetramethylbutyl) -6— (2H Benzotriazole-2-phenol) phenol], 2-— (4, 6 Diphenyl-1-phenol 1, 2, 5 Triazine-2-yl) 5— [(Hexyl ) Oxy] phenol, 2, 6 naphthalenedicarboxylic acid (hereinafter abbreviated as “NDC”) Application) is preferred.

[0069] The light stabilizer may be a single polymer or a combination of two or more kinds, or a good polymer. Further, it may be a copolymer component for polyester or the like.

[0070] In particular, as long as it is a photostable dicarboxylic acid such as 2,6-naphthalenedicarboxylic acid, it may be a polyester (including a copolymer) composed of the dicarboxylic acid as a dicarboxylic acid component. . Specific examples include polyethylene naphthalate (hereinafter abbreviated as “PEN”), and a copolymer of 2,6-naphthalenedicarboxylic acid copolymerized with PET. In this case, the content of the light stabilizer in the film is the amount of the light stabilizer component present in the polyester or the like (including the copolymer).

[0071] Further, an inorganic light stabilizer may be added within a range in which the performance is not deteriorated. Inorganic light stabilizers include titanium oxide and zinc oxide. Titanium dioxide is preferably used for improving the light and light stability.

[0072] When an inorganic light stabilizer is used, the inorganic light stabilizer can also serve as the above-described large particle size particles or inorganic particles that form fine bubbles.

[0073] When titanium dioxide is added, its average particle size is not particularly limited as long as it does not impair optical properties, but is preferably equal to or less than the average particle size of the large particle size (the large particle size is If not, it is less than 1.0 111), more preferably less than the average particle size of large particles and 0.1 m or more and 5 ^ 111 or less.

[0074] Further, the content of titanium dioxide is preferably 1% by weight or more and 40% by weight or less, more preferably 5% by weight or more and 20% by weight or less, more preferably, based on the total weight of the polyester film. 5 to 15% by weight. When the content of titanium dioxide is more than 40% by weight, the film formation becomes unstable, and the optical properties may be deteriorated due to the light hiding property of the titanium dioxide particles. On the other hand, if the addition amount of titanium dioxide is less than 1 wt%, there is no deterioration of the optical performance, the effect of improving light stability is expressed Nikuiko and power ^s.

[0075] When the polyester film of the present invention adopts embodiment 1, it is preferable that the polyester layer (B) contains a predetermined amount of titanium dioxide. In addition, as long as the characteristics are not impaired, the polyester layer (A) may contain titanium dioxide. Light to the polyester layer (B) The content of the stabilizer is preferably 5 to 20% by weight, more preferably 5 to 15% by weight, based on the total weight of the polyester layer (B). When the content of titanium dioxide is more than 20% by weight, the optical properties are reduced due to the light hiding property of the titanium dioxide particles. On the other hand, when the amount of titanium dioxide added is less than 5% by weight, the optical performance is not deteriorated, but the effect of improving the photostability may be hardly exhibited.

[0076] Light stabilizers have light in the ultraviolet region, particularly a peak with an absorption wavelength in the wavelength region of 340 nm to 350 nm, but in most of them, the light absorption region is in the visible light region (wavelength of 380 nm or more). Has reached. This appears yellowish when a light stabilizer is added to the white polyester film. This yellow tint causes a decrease in luminance when used as a white polyester film for a liquid crystal display reflector, and also affects the design of other optical members such as fluorescent tubes. For this reason, the light stabilizer may be required to keep the yellowness low.

[0077] Light stabilizers having an absorption wavelength not in the visible light region, such as tetraethyl-2,2 '-(1,4 phenylene-dimethylidene) bismalonate, malonic acid [(4-methoxyphenyl) -methylene]- Yellowness can be kept low by using dimethyl ester, 2 ethyl, 2,1 ethoxyxarulanilide, and 2,6 naphthalenedicarboxylic acid.

[0078] As described above, malonic acid [(4-methoxyphenyl) -methylene] -dimethyl ester and 2,6 naphthalene diphenol are from the viewpoint of compatibility with polyester and no absorption wavelength in the visible light region. Acid is the most preferred!

[0079] [Layer containing antistatic agent (C)]

In the white polyester film of the present invention, it is not preferable that dust adheres to the white polyester film of the present invention, particularly in processing and assembly processes. Therefore, it is preferable to provide a layer (C) containing an antistatic agent on at least one side of the white polyester film.

[0080] In the present invention, the layer (C) containing an antistatic agent is formed by stretching an aqueous coating solution in at least one direction after coating and drying from the viewpoint of environmental pollution prevention and explosion-proof properties during film production. It is preferably formed in a production process in which a base film composed of a polyester layer (A) and a polyester layer (B), which is preferably a coating layer, is biaxially oriented. The stretching timing is not particularly limited, but stretching in at least a uniaxial direction after applying the coating liquid. Is preferred. Specifically, a method of biaxially stretching after applying an aqueous coating liquid, or a method of applying an aqueous coating liquid after longitudinal (film longitudinal direction) stretching and further laterally stretching is preferably used. Examples of the application method of the aqueous coating liquid include various application methods such as a reverse coating method, a gravure coating method, a rod coating method, a bar coating method using a metering bar, a die coating method, and a spray coating method. The force that can be preferably used is not limited to these.

[0081] The aqueous coating liquid may contain a slight amount of an organic solvent for the purpose of assisting the stability of the coating liquid. Examples of the organic solvent include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, di-xane, cyclohexanone, n-hexane, tolylene, xylene, methanol, ethanol, n-propanol, and isopropanol. Can do. Multiple organic solvents may be contained.

[0082] In the present invention, the aqueous coating liquid contains other surfactants, ultraviolet absorbers, pigments, lubricants, anti-blocking agents, water-soluble substances within a range that does not impair the object of the present invention. The ability to combine crosslinkers such as water-soluble polymer resins, oxazolines, melamines, epoxies, and aziridines and other antistatic additives.

[0083] From the viewpoint of the appearance of the coating film, the solid content concentration in the aqueous coating liquid in the present invention is preferably 5 to 30% by weight, more preferably 5 to 20%.

[0084] The thickness of the layer (C) containing the antistatic agent is preferably from 0 · 01 to 2111, more preferably from 0.1 to 1111. If the thickness is too thin, the solvent resistance and antistatic property may be insufficient, and if the thickness is too thick, the slipperiness may be inferior.

[0085] In the present invention, the surface resistivity of the layer containing the antistatic agent (C), 23 ° C, the surface resistivity at a relative humidity of 50% is 1 X 10 ¹³ Ω / mouth or less, preferably 10 It is preferably ⁷ Ω / port or more and 10 ¹³ Ω / port or less. If the surface specific resistance value is less than 10 ⁷ Ω / mouth, the surface adhesion and film forming property may be inferior. If the surface specific resistance value is greater than 10 ¹³ Ω / mouth, the antistatic property will be insufficient. As a result, the antifouling property may be insufficient. In the present invention, the surface specific resistance value is measured, for example, by the following method. When using a surface resistivity measuring instrument (ΜΜΑΠ—17A) manufactured by Kawaguchi Denki Seisakusho, leave the sample in an atmosphere of 23 ° CX 50% RH for 1 day, then apply a voltage of 500V for 1 minute. After leaving, the surface of the coated surface Measure the surface resistivity. Here, the electrode type is a company-made product (model No. P-618), which is a concentric electrode with a main electrode outer diameter of 90 mm and a counter electrode inner diameter of 45 mm.

[0086] [Antistatic agent (P)]

The antistatic agent (P) added to the layer (C) containing the antistatic agent in order to develop the above-mentioned antistatic properties (surface specific resistance value) includes metal powder, tin oxide-antimony based conductive agent, The antistatic agent used is resistant to heat and has little coloration due to the same requirements as those required when selecting the light stabilizer described above. Selection of V, which does not adversely affect the reflection characteristics of resin and film is desirable. The antistatic agent satisfying the above conditions is not particularly limited. For example, a polycation polymer (P-1) containing a compound comprising a polyethylene sulfonate group or a compound containing a carboxylate group, and a conductive high The molecular polymer (P-2) and are preferably. The antistatic agent is added in an amount of 10 to 60 parts by mass, preferably 15 to 5% of the antistatic agent (P-1) made of polycation polymer, based on the total weight of the layer (C) containing the antistatic agent. 50 parts by mass. When this ratio is less than 10 parts by mass, the antistatic property is low, and when it is 60 parts by mass or more, the layer (C) having the antistatic agent becomes unstable, causing aggregation, cracks, etc., and the film becomes cloudy or charged. The prevention property is lowered and the heat resistance is also likely to be lowered.

[0087] In the case of the conductive polymer (P-2), the addition amount is preferably 5 to 40 parts by mass with respect to the total weight of the layer (C) containing the antistatic agent, more preferably 5 ~ 30 parts by mass. When the amount is 5 parts by mass or less, the antistatic property is lowered. On the other hand, when the amount is 40 parts by mass or more, the layer (C) having an antistatic agent becomes unstable, causing aggregation, cracks, and the like, and the film is white. Turbidity 'antistatic property is lowered, and heat resistance is likely to be lowered. On the other hand, details of the polycation polymer (P-1) and the conductive polymer polymer (P-2) are described below.

[0088] [Polycationic polymer (P-1)]

The polycation polymer (P-1) that can be selected as an antistatic agent in the present invention is heat resistant, has little coloration, and does not adversely affect the reflection characteristics of the resin and film! Preferred are copolyesters comprising a compound comprising or a compound containing a carboxylate group! [0089] The cation component of the sulfonate group includes, for example, a force S including sulfoterephthalic acid, 5 sulfoisophthalic acid, 4 sulfoisophthalic acid, 4 sulfonaphthalene-1,2 dicarboxylic acid, and the like. It is not a thing. Examples of the cation component of the carboxylate group include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methinolecyclohexene 1, 2, 3 3, 4, tert-tetracarboxylic acid, 5- (2,5 dioxotetrahydrofurfuryl) -3 cyclohexene-1, 2 dicarboxylic acid, cyclopentanetetracarboxylic acid, 2, 3, 6, 7 naphthalene Tetracarboxylic acid, 1, 2, 5, 6 naphthalenetetracarboxylic acid, ethylene glycol bistrimethylate, 2, 2 ', 3, 3'-diphenyltetracarboxylic acid, thiophene 2, 3, 4, 5 The power of ethylene tetracarboxylic acid and the like is not limited to these. Among these sulfonic acids and carboxylic acids, sulfoterephthalic acid, 5-sulfoisophthalic acid, and 4-sulfoisophthalic acid, which have excellent heat resistance and adhesion to the polyester layer (A) or (B) described later, are used. Most preferred!

[0090] Examples of the anion component of the sulfonate group and carboxylate group include ammonium ion, strong ion, sodium ion, lithium ion, and the like. From the viewpoint of antistatic property and film forming property, ammonium ion, It is preferable to use lithium ions.

[0091] As the polycation polymer, a polymer having a structure represented by the following formula (I) as a main repeating unit can also be suitably used.

[0092] [Chemical 1]

2l3yehi l 1 J >> yo¾i

Size

(Wherein R and R are each H or CH, R ³ is an alkylene having 2 to 10 carbon atoms;

Three

R ⁴ and R ⁵ are each a saturated hydrocarbon group having 1 to 5 carbon atoms, R ⁶ is an alkylene group having 2 to 10 carbon atoms, and p is! ~ 20 number, q is;! ~ 40 number, Y- is halogen ion, mono or poly It is a halogenated alkyl ion, nitrate ion, sulfate ion, alkyl sulfate ion, sulfonate ion or alkyl sulfonate ion. ) Of the antistatic agents of the above formula (I), alkylsulfonates in which Y_ in the formula (I) is represented by R ⁷ SO—

Three

(Wherein R ⁷ is a saturated hydrocarbon group having 1 to 5 carbon atoms) and R ^{3 in} — (OR ³ ) —

m

L group, p force S; number of! ~ 20, (R ^e O) one R ⁶ is ethylene group, q is the number of 1-40, the adhesion between the coating film and the polyester film And heat resistance of the coating film are favorable, and particularly excellent in antistatic properties.

[0094] The polycation polymer (P-1) can be preferably produced, for example, by the following method. That is, an acrylic acid ester monomer is converted into an ester ester having a weight average molecular weight of 2000 to 100000 by emulsion polymerization, and then N, N dianolenoaminoaminoalkylamine (for example, N, N dimethylaminopropylamine). , N, N jetylaminopropylamine, etc.) and amidation, and finally quaternary hydroxyalkylation reaction is performed to introduce a quaternary cation pair.

[0095] The polycationic polymer (P-1) is represented by Y—CH 2 CH 2 SO—, C 3 H 2 SO—, or

3 3 2 5 3 or CH 2 SO—, (OR ³ ) one is one (OC H) one, and p is;

3 7 3 p 2 4 p

Are preferred. Also, one (R ⁶ 〇), one is one (CHO) —, and q is;! ~ 10 α 2 4 ¾

Is preferred.

[0096] As the polycation polymer (Ρ1), polymers represented by the following formulas (II) and (III) can also be suitably used.

[0097] [Chemical 2]

ax =

in

CM

X

R 1 and R 2 above are each an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, an aryl group, or an achiral group. Among these, an alkyl group having 1 to 6 carbon atoms is preferable.

[0100] Each of the above R ¹³ R ¹⁶ is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, an aryl group, an arachiral group, etc., and R ¹⁷ R ¹⁸ is an alkylene group and a cycloalkylene group having 2 to 10 carbon atoms each; , Arylene group, allylalkylene group, and divalent aliphatic group containing a heteroatom (0 N, etc.). This aliphatic group includes CH (OH) CH- CH CH (OH) CH- C

2 2 2

One example is H CH CH NHCOCH CH CH.

2 2 2 2 2 2

[0101] These may be homopolymers or copolymerized with other unsaturated monomers.

When copolymerized with other unsaturated monomers, the above repeating units are preferably composed of 50 mol% or more. If it is less than 50 mol%, the antistatic property is insufficient. Other unsaturated monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, croton Methyl acid, glycidyl metatalylate, acrylic metatalylate, attalinoleamide, methacrylolamide, N methylolacrylamide, ethylene, styrene, butyl acetate, acrylic nitrile, methacryl nitrile, butyl chloride, vinylidene chloride, dibutene benzene , Acrylic acid, methacrylic acid, maleic acid, fumaric acid.

[0102] [Conductive polymer (P-2)]

As the conductive polymer (P-2) that can be selected in the present invention, an antistatic polymer, pyrrole and / or obtained by polymerizing thiophene and / or thiophene derivatives. Examples include antistatic polymers obtained by polymerizing pyrrole derivatives.

Yes

[0103] The antistatic polymer obtained by polymerizing thiophene and / or thiophene derivative is a homopolymer or copolymer having a unit represented by the following formula (1) and / or formula (II) as a main component It may be a copolymer and a copolymer containing a small amount of other polymerized units as a copolymerization component.

[0104] [Chemical 4]

[0105] [Chemical 5] CH ₂ ½ 0

I I

……)

II II

(m = 1 ~ 4)

[0106] Formula (I)

R ² is each a hydrogen element (one H), an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group or an aromatic hydrocarbon group, a hydroxyl group (one OH), and a group having a hydroxyl group at the terminal (— R ³ OH: R ³ is a divalent hydrocarbon group having 1 to 20 carbon atoms (for example, an alkylene group, arylene group, cycloalkylene group, alkylene'arylene group, etc.), an alkoxy group (one OR ⁴ : R ⁴ Is a hydrocarbon group having 1 to 20 carbon atoms), a group having an alkoxy group at the terminal (—R ³ OR ⁵ : R ⁵ is an alkyl group having 1 to 4 carbon atoms), a carboxyl group (—COOH), a carboxyl base ( — COOM: M is an alkali metal element, quaternary amine or tetraphosphonium), a group having a carboxyl group at the end (—R ³ COOH), a group having a carboxyl base at the end (—R ³ COOM), Ester group (—COOR ⁵ ), group having terminal ester group (—R ³ COOR ⁵ ), sulfonate group (SO H), sulfonate group (SO M), terminal sulfone

3 3

A group having an acid base (—R ³ SO M), a sulfonyl group (one SO R ⁴ ), and a sulfonyl group at the terminal

3 2

Group (—R ³ SO R ⁴ ), sulfenyl group (—S (= 〇) R ⁴ ), and terminal sulfenyl group

2

Groups (R ³ S (═O) R ⁴ ), acyl groups (C (═O) R ⁶ : R ⁶ is a hydrocarbon group having 1 to 10 carbon atoms), groups having terminal acyl groups (one R ³ C (= 〇) R ⁶ ), amino group (one NH), terminal

2

A group having a mino group (one R ³ NH), a part of or all of the hydrogen elements of the amino group being substituted

2

Group (NR ⁷ R ⁸ : R ⁷ is a hydrogen element, an alkyl group having 1 to 3 carbon atoms, —CH 0 H or —CH

twenty two

○ R ⁶ R ⁸ is an alkyl group having 13 carbon atoms, CH ○ H or — CH ○ R ⁶ ), water of an amino group

twenty two

A group having one or all of the elementary elements substituted at the end (one R ³ NR ⁷ R ⁸ ), a force rumomoyl group (—CONH), a group having a force rubamoyl group at the end (—R ³ CONH or R ³

twenty two

NHCONH), a group in which some or all of the hydrogen atoms of the rubamoyl group are substituted (one C

2

ONR ⁷ R ⁸ ), a group having one or all of the hydrogen elements of the rubamoyl group substituted at the end (one R ³ CONR ⁷ R ⁸ ), a halogen group (one F Cl Br I), R ⁴ A group in which a part of the hydrogen element is substituted with a halogen element, a group represented by — [NR R ^] [X (where R ⁹ is a hydrogen element or a hydrocarbon group having! -20 carbon atoms, X— is F—Cl Br_ Γ R'OSO

3 R'S

O_NO— or I ^ COO—), phosphate group (P (= 0) (OM)), powder

3 3 2 A group having a phosphate group at the end (-R ³ P (= 〇) (OM)), oxysilane group, or terminal

2

It is a group having a xylan group.

In addition, the antistatic polymer obtained by polymerizing thiophene and / or thiophene derivative is added with a doping agent in order to improve the antistatic property, for example, with respect to 100 parts by weight of the antistatic polymer. ; 500 parts by weight can be blended. As this doping agent, LiCl I ^ COOL R " ³ : Carbon number;! ~ 30 saturated hydrocarbon group), R ^1Q SO Li

3 R

¹⁰ COONa R ¹⁰ SO Na R ¹⁰ COOK R ¹⁰ SO K, tetraethylammonium, I BF

3 3 2 3

Na BF Na HCIO CF SO H FeCl, Tetracyanoquinoline (TCNQ) Na B CI

4 4 3 3 3 2 10

, Phthalocyanine, porphyrin, glutamine III, alkyl sulfonate, polystyrene

Ten

Examples thereof include sulfonic acid, polystyrene sulfonate Na (K Li) salt, styrene 'styrene sulfonate Na (K Li) salt copolymer, styrene sulfonate anion, styrene sulfonate' styrene sulfonate anion copolymer. In particular, a homopolymer or copolymer having as a main component a unit represented by the above formula (II) and a combination of polystyrene sulfonic acid as a doping agent (the following formula (IV)) is preferable.

[0109] [Chemical 6]

(IV)

[0110] The antistatic polymer obtained by polymerizing pyrrole and / or a pyrrole derivative is, for example, a homopolymer or a copolymer having as a main component a unit represented by the following structural formula. A copolymer containing a small amount of a unit as a copolymerization component may be used.

[0111] [Chemical 7]

R,

[0112] Here, R ¹ is hydrogen or an alkyl group, and R ^{2 to} R ³ are hydrogen, an alkyl group, a carboxylic acid (salt) group or a sulfonic acid (salt) group-containing group, a halogen-containing group, an ester group, respectively. Or it is an ether group.

[0113] The antistatic polymer can be produced by polymerizing these pyrroles and pyrrole derivatives by a known method (for example, an acid polymerization method, an electrolytic polymerization method, etc.). As this pyrrole and pyrrole derivative, pyrrole in which ~ is hydrogen,

In R ³ are hydrogen, can be R ² is a pyrrole derivative is Al kill group, in which R ¹ is hydrogen, R ² and R ³ are preferably exemplified pyrrole derivative is an alkyl group. Examples of this pyrrole derivative include N-substituted pyrrole such as pyrrolinole and N-alkylpyrrole, and 3-alkylpyrrole having a C1-C6 alkynole group, alkoxy group or halogen group at the 3rd, 3rd, or 4th position. 3,4-Dianolecylpyronole, 3-Dianoloxypyrrolone, 3,4-Dianoloxypyrrolone, 3-Chloropyrrole, 3,4-Dichloropyrrole are preferred.

[0114] [Vehicle material (Q)]

Moreover, as the vehicle material of the layer (C) having an antistatic agent, the film forming property is dramatically improved by selecting a component having interfacial adhesion with the polyester layer (A) or (B). Although it will not specifically limit if it is a component satisfying this condition, polyester resin, acrylic resin, urethane resin, epoxy resin, silicone resin, urea resin, phenol resin, etc. Although it can be mentioned, it is preferable to use a copolymerized polyester resin and a copolymerized acrylic resin. The acid component constituting this copolyester resin includes terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, phenylindane. Examples thereof include dicarboxylic acid and dimer acid. Two or more of these components can be used. In addition, a small percentage of unsaturated polybasic acids such as maleic acid, fumaric acid, and itaconic acid, and hydroxycarboxylic acids such as p-hydroxybenzoic acid and p- (β-hydroxyethoxy) benzoic acid may be used together with these components. it can. Unsaturated polybasic acid component proportion of Ya hydroxycarboxylic acid component is at most 10 mol ^_0/0, preferably 5 mole ^_0/0 or less. The polyol components include ethylene glycolol, 1,4 butanediole, neopentinoleglycolanol, diethyleneglycolinole, dipropyleneglycolinole, 1,6-hexanediol mononole, 1,4-cyclohexanedimethanol, and xylylene. Examples include glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, poly (ethyleneoxy) glycol, poly (tetramethyleneoxy) glycol and the like. Two or more of these can be used. Among these, by selecting a copolyester containing isophthalic acid and diethylene glycol, the adhesion at the interface can be optimized, and the solvent resistance can be imparted. Since the recoverability is also excellent, it can be suitably used. Isophthalic acid content of the heavy composite spectral preferably the gesture et preferred is 65 to 95 mole ^_0/0 Ru 70-95 mole ^_0/0 der. Further, the amount of diethylene glycol as the polymerization component is preferably from 50 to 95 mol%, more preferably from 60 to 90 mol%. As other copolymer components, known dicarboxylic acids and diols can be used, but are not limited thereto. The range of the glass transition point of the polymerized polyester is preferably 0 to 60 ° C, more preferably 10 to 45 ° C.

On the other hand, the constituent components of the copolymerized acrylic resin include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, sodium acrylate, ammonium acrylate, 2-hydroxyxethyl acrylate, methacrylic acid, methacrylic acid. Methyl acid, Ethyl methacrylate, Butyl methacrylate, Sodium methacrylate, Ammonium methacrylate, 2-Hydroxyethyl methacrylate, Glycidyl methacrylate, Acrylic methacrylate, Sodium vinyl sulfonate Examples thereof include sodium methallyl sulfonate, sodium styrene sulfonate, acrylamide, methallyl amide, N-methylol methacrylamide and the like. These monomers can be used in combination with other unsaturated monomers such as styrene, butyl acetate, acrylonitrile, methacryl nitrile, butyl chloride, vinylidene chloride and dibutylbenzene.

[0116] Further, as the acrylic copolymer, a modified acrylic copolymer, for example, a block polymer obtained by modifying the acrylic copolymer with polyester, polyurethane, silicone, epoxy, phenol resin, or the like, or a graft polymer is used. You can also.

[0117] The content of the vehicle material is preferably 60 to 95 parts by mass with respect to the total amount of the resin forming the layer (C) having the antistatic agent. If the content is too small, the solvent resistance and the interfacial adhesion to the polyester layer (A) or the polyester layer (B) may be inferior. If the content is too large, the antistatic property may be inferior.

[0118] [Surfactant]

In the antistatic coating film of the present invention, the surfactant (R) is used to make the adhesion between the coating film and the polyester film strong and to improve the blocking resistance of the antistatic laminated film. Is preferably blended. Examples of the surfactant (R) include alkylene oxide homopolymers, alkylene oxide copolymers, aliphatic alcohols / alkylene oxide adducts, long chain aliphatic substituted phenol / alkylene oxide addition polymers, polyvalent Nonionic surfactants such as alcohol aliphatic esters and long-chain aliphatic amide alcohols, cationic compounds such as compounds having quaternary ammonium salts, compounds having alkyl pyridinium salts, compounds having sulfonates, etc. Anionic surfactants can be mentioned, and nonionic surfactants are particularly preferable because they have excellent effects on the adhesion between the coating film and the polyester film and the blocking resistance of the antistatic polyester film.

[0119] The content of the surfactant is from! To 15 parts by mass, preferably from 3 to 10 parts by mass, based on the total amount of the resin forming the layer (C) having the antistatic agent. If this ratio is less than 1 part by mass, the wettability of the aqueous coating liquid to the polyester film may be insufficient, and if it exceeds 15 parts by mass, the adhesion of the coating film to the polyester film may be insufficient, or the blocking resistance may be reduced. It may be insufficient. [0120] [Film Formation Method]

Next, the present invention is not limited to the power and examples described for the production method of the white polyester film. Polymethylpentene as an incompatible thermoplastic resin, polyethylene glycol, polybutylene terephthalate and polytetramethylene glycol copolymer as low specific gravity agents are mixed with polyethylene terephthalate, and mixed thoroughly and dried to 270 ~ Feed to Extruder A heated to 300 ° C. Light stabilizer and, if necessary, polyethylene terephthalate containing inorganic additives such as SiO

2

The polyester layer (B) / polyester layer (A) / polyester layer (B) so that the polyester layer (B) polymer is on both surface layers in the T die 3 layer die. ) Can be laminated to 3 layers! /

[0121] A roll group in which 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 heated to 80 to 120 ° C. Then, the film is longitudinally stretched 2.0 to 5.0 times in the longitudinal direction and cooled with a roll group of 20 to 50 ° C. Subsequently, a coating solution for forming the layer (C) containing the antistatic agent is applied by a bar coating method using a metalling bar, and then the tenter is held while holding both ends of the longitudinally stretched film with clips. Lead Stretch in the direction perpendicular to the longitudinal direction in an atmosphere heated to 90-140 ° C. The stretching ratio is preferably a force S for stretching 2.5 to 4.5 times in the longitudinal and lateral directions, and the area ratio (longitudinal stretching ratio X lateral stretching ratio) is 9 to 16 times. If the area magnification is less than 9 times, the whiteness of the film obtained becomes poor. Conversely, if the area magnification exceeds 16 times, the film tends to be broken during stretching and the film forming property tends to be poor. In order to give the flatness and dimensional stability of the biaxially stretched film in this way, heat setting at 150 to 230 ° C in a tenter, uniform cooling, and cooling to room temperature are taken up. Obtain white polyester film / rem for LCD reflectors.

[0122] The white polyester film for a reflector of a liquid crystal display according to the present invention obtained by force, has a high reflectivity because at least one surface has a high gloss, less diffuse reflection, and fine bubbles are formed inside the film. Therefore, high luminance can be obtained when it is used as a reflector for a reverse prism type liquid crystal display. It also has excellent durability against ultraviolet light. [0123] The configuration of the white polyester film for a liquid crystal display reflector of the present invention is a laminated structure using the polyester layers (A) and (B) as described above, and the layer (A) is a front layer. The layer containing fine bubbles is preferable for achieving both high reflectivity and film forming properties. In addition, it is preferable to add inorganic particles and / or organic particles to the polyester whose film surface is preferably a polyester layer (B), and to the total weight of the polyester layer (B) (layer containing inorganic particles and / or organic particles). On the other hand, a layer containing 0.5% by weight or less, preferably 0.1% by weight or less, more preferably 0.07% by weight or less is convenient for improving the specular reflectivity. In addition, the reverse prism method has a structure in which the reflector 12 in FIG. 1 is in close contact with the light guide plate 13 due to its configuration, and it is easy to cause a problem that inorganic particles fall off and scratch the light guide plate. ing. If the amount of added particles exceeds 0.5% by weight, scratches are likely to occur due to particle dropping. Therefore, the amount of added particles should be 0.5% by weight or less. S is preferable, and more preferably 0.1% by weight. % Or less.

[0124] [Measurement of physical properties and evaluation method of effects]

The physical property value evaluation method and the effect evaluation method of the present invention are as follows.

[0125] (1) Film thickness (total thickness of each layer)

The film thickness was measured at 10 points with a calibrated digital micrometer (M-30, manufactured by Sony Precision Technology), and the average value was taken as the film thickness.

[0126] (2) Thickness of each layer

The film was sampled to 5 mm X lcm and pressed in the cross-section direction on ice using a microtome. Using a transmission electron microscope HU-12 (manufactured by Hitachi, Ltd.), the cross section of the cut polyester layer (A) and polyester layer (B) of the cut sample was observed and magnified 250 times. From this, the laminate thickness was converted and determined.

[0127] (3) Average particle size

(Inorganic particles)

Using a Hitachi S-2100A scanning electron microscope at a magnification of 10,000, 100 particles were randomly selected as inorganic particles before being added to the resin (film). For 100 particles, the particle size was measured, 5 particles were removed from the largest and 5 particles from the smallest, and the average particle size was determined from the remaining 90 particles (particles were spherical). If it is not a shape, it is approximated to the closest ellipse, and the ellipse is calculated by (major axis + minor axis) / 2).

(Incompatible resin)

Cut out a film sample into a square, fix it in an embedding capsule, and embed it in an epoxy resin. After the embedded sample was cut into a thin film section with a thickness of 50 nm using a microtome (ULTRACUT-S), the section parallel to the film-forming direction was used, and the magnification was set to 10,000 using a Hitachi S-2100A scanning electron microscope. Observed and photographed, and randomly selected 100 particles. For 100 particles, the particle size was measured, 5 particles were removed from the largest and 5 particles from the smallest, and the average particle size was determined from the remaining 90 particles (if the particles were not spherical) Approximate the ellipse closest to the shape, and (obtained by (major axis + minor axis) / 2 of the ellipse).

[0128] (4) Film formation stability

Whether the film could be stably formed was evaluated according to the following criteria.

○: Stable film can be formed for more than 1 hour.

X: Breakage occurs within 1 hour, and stable film formation is not possible.

[0129] (5) Film adhesion

The film after film formation was cut into a size of 0.5 m × 0.5 m, and the coated surface was visually observed to count the number of oval defects peculiar to missing coating.

○: 30 or fewer defects

X: 30 or more defects

½) Reflectance

Attach an integrating sphere to a Hitachi High-Technologies spectrophotometer (U-3310), and measure the reflectance from 400 to 700 nm when the standard white plate (aluminum oxide) is 100%. Read the reflectance at 5nm intervals from the obtained chart and calculate the average value to obtain the average reflectance.

[0130] (7) Surface resistivity (antistatic property)

Using a surface resistivity meter (製 -17A) manufactured by Kawaguchi Electric Mfg., Leave the sample for 1 day in an atmosphere of 23 ° CX 50% RH. Apply a voltage of 500V and leave it for 1 minute, then the surface of the coated surface The surface resistivity was measured. The electrode type used here is a company-made (model number P-618), which is a concentric electrode with an outer diameter of 90 mm for the main electrode and an inner diameter of 45 mm for the counter electrode.

[0131] (8) Surface roughness

Surface average roughness Ra and ten-point average surface roughness Rz are manufactured by Kosaka Laboratory, stylus type surface roughness meter

(Model number: SE-3FA). The conditions were as follows. The average of the five measurements was taken as the direct correction.

• Radius tip radius: 0.5 μ ΐη

• Stylus load: 5mg

• Measurement length: 0.8mm

• Cut-off value: 0 · 08mm.

[0132] (9) Dust adhesion (ash test)

A white polyester film cut to A4 size was conditioned for 24 hours in a measurement atmosphere of 23 ° C and 50% RH. The conditioned film surface was rubbed 10 times with a friction cloth (wool 100%). The film was immediately pre-dried at 70 ° C. for 1 hour, and 1.5 g of tobacco ash was gradually brought close to and brought into contact with a desk spread over a range of 10 cm × 10 cm. Tobacco ash adhesion was determined visually. Δ or more is acceptable.

○: Even if the film is brought into contact with ash, it does not adhere.

(Triangle | delta): It adheres when a film is contacted with ash.

X: Adheres only by bringing the film close to ash.

[0133] (10) Color tone

Using a color meter SM-6 manufactured by Suga Test Instruments, Lab color tone was measured in the reflection mode in the C light 2 ° field of view.

[0134] (1 1) Ultraviolet irradiation test

Light resistance was evaluated by irradiating the sample with ultraviolet rays using an I-Super UV tester (model number: SUV-W131) manufactured by Iwasaki Electric and measuring the color tone b value before and after the irradiation. In the present invention, the irradiation UV amount was 100 mW / cm ² at a wavelength of 365 nm, and the UV irradiation time was 4 hours.

[0135] (12) Specific gravity The film is accurately sampled at lOcm x 10cm and weighed accurately to the nearest 0.1 mg using an electronic balance (Yuji 100 made by ^^ ₁₆ ). After taking the weighed sample, measure the total thickness of each layer of the film using a constant pressure thickness measuring instrument, and apply the following formula to calculate the specific gravity.

Specific gravity = (Weighed value (g)) / (Total thickness m of each layer)) X 100.

[0136] (13) Screen brightness (luminance)

As shown in FIG. 1, the reflection film 12 of the four-light type backlight of the liquid crystal monitor (750B) manufactured by Samsung Corp. was changed to the reflection film produced in each example and comparative example, and measurement was performed. For luminance measurement, use a 100V household power supply and switch the ON / OFF switch to apply the voltage. I waited for the brightness of the cold-cathode tubes to become uniform. Thereafter, the luminance was measured with a luminance meter 15 (BM-7fast manufactured by topcon) at a measurement distance of 500 mm. The average number of measurements shall be 3 times. For the evaluation of the luminance value, a relative evaluation with Toray reflective film E6SL (total thickness of each film layer 250 μm) as 100 was used.

Example

The present invention will be described based on examples.

[0138] [Examples !! ~ 19]

The raw materials shown below were mixed with the raw materials shown in Table 1 for the raw material polymer of the polyester layer (A). The extrusion temperature was set to 320 ° C, and it was prepared by supplying to Extruder A heated to 270 to 300 ° C.

'Polyethylene terephthalate chip (F20S manufactured by Toray Industries, Inc.)

• 4000 molecular weight polyethylene glycol, copolymer of polybutylene terephthalate and polytetramethylene glycol ("Hytrel" manufactured by Toray DuPont Co., Ltd.)

'A copolymer of polyethylene terephthalate copolymerized with 10mol% isophthalic acid and 5mol% polyethylene glycol (T794M manufactured by Toray Industries, Inc.)

• Polymethylpentene (TPX820 manufactured by Mitsui Chemicals, Inc.)

• Silica particles with average particle sizes listed in Table 1

'Polyethylene naphthalate (Aldrich, d = 1.328, m.p.250-290 ° C)

On the other hand, light stabilizers a to d listed below on polyethylene terephthalate chips One type, silica particles with an average particle diameter of 3 · 2 m, and titanium dioxide with an average particle diameter of 0 · 2 m, mixed in the proportions shown in Table 2, were vacuum-dried at 180 ° C for 3 hours, then 280 The raw material polymer of the polyester layer (B) was produced by supplying to the extruder B heated to ° C. a: Malonic acid ester light stabilizer ("B-CAP" manufactured by Clariant Japan Co., Ltd.) b: Malonic acid ester light stabilizer ("PR-25" manufactured by Clariant 'Japan Co., Ltd.) c: Triazine-based light stabilizer (Ciba 'Specialty Chemicals'"CGX006") d: Benzophenone-based light stabilizer (Asahi Denka Co., Ltd. "ADK STAB LA-51").

[0139] The composition of the coating solution for forming the layer (C) containing the antistatic agent is as follows. Nippon Carbide Co., Ltd. coating Nikiroku sol RX- 7013ED (acrylic polyester resin emulsion: indicated as X in Table 3) and Japan NSC coating Versa YE- 910 (Polyester lithium sulfonate lithium salt antistatic agent : Indicated by Y in Table 3) In a solid mass ratio, RX-7013ED and YE-910 mixed in the proportions shown in Table 3 were diluted with water, and the surfactant RY-2 manufactured by Interactive Chemical Co., Ltd. It was prepared by adding 0.1% of the liquid ratio. The coating layer (C) was provided on one surface of the film, and this surface was designated as A surface.

[0140] The raw material polymers of the polyester layers (A) and (B) were laminated through a laminating apparatus so that the layer constitution and the layer thickness were as shown in Table 1, and formed into a sheet by a T-die. Furthermore, this film was cooled and solidified with a cooling drum with a surface temperature of 25 ° C, and the unstretched film was guided to seven rolls whose heating temperature was adjusted to 85 to 98 ° C, and stretched 3.4 times in the longitudinal direction. And cooled in a 25 ° C mouth group. Subsequently, a coating solution for forming a layer (C) containing an antistatic agent was applied by a bar coating method using a metallizing bar to form a C layer. The coated film thus obtained was stretched by 3.6 times in the direction perpendicular to the longitudinal direction in an atmosphere heated to 130 ° C. while being held by both ends with a lip and guided to a tenter. Thereafter, heat setting was performed at 190 ° C. in a tenter, and after uniform cooling, the film was cooled to room temperature to obtain a film having a winding thickness of 250 m. Table 9 shows the physical properties of the obtained film as a reflector substrate. In either case, the antistatic property was good on at least one film surface.

[0141] The types and contents of light stabilizers are as shown in Table 7. Silica, barium sulfate, titanium dioxide, and polymethylpentene contained in the film all formed V and fine bubbles in the film. [0142] [Examples 20 to 52]

The raw materials for the polyester layer (A) and polyester layer (B) shown in Tables 4 and 5 were supplied to two extruders heated to 280 ° C, respectively. Then, they were merged using a multi-layer feed block device, and formed into a sheet from a die while maintaining the laminated state. Further, the unstretched film obtained by cooling and solidifying this sheet with a cooling drum with a surface temperature of 25 ° C is heated at 90 ° C, stretched 2.9 times in the longitudinal direction (longitudinal direction), and cooled with a roll group at 25 ° C. did. The following aqueous coating liquid was applied to one surface or both surfaces of this uniaxially stretched film at a coating amount of 4 g / m ² (wet) by the microgravure coating method.

[0143] Here, in Tables 4 and 5, the copolymerized polyester used is a copolymer of dicarboxylic acid component or diol component in the amount of copolymerization (mol%) described in the table. The finished polyester is shown. In the table, IPA is isophthalic acid (dicarboxylic acid component), and CHDM is cyclohexanedimethanol (diol component).

[0144] In addition, water-based coating solution, the acid component is terephthalic acid [67 mol ^_0/0], isophthalic acid [27 mol ^_0/0] and 5-Na sulfoisophthalic acid [6 mol%, the glycol component is ethylene glycol Copolymerized polyester (Tg = 51 ° C) consisting of [30 mol%], diethylene glycol [40 mol%] and neopentylglycol [30 mol%] (denoted q in Table 6) is the vehicle material (Q). Polystyrene sulfonate Na (Chemistat SA-9, manufactured by Sanyo Kasei) (shown as p-1 in Table 6) or polythiophene water dispersion (Vitron P, manufactured by Bayer) (shown as p-2 in Table 6) )) As the antistatic agent (P), polyoxyethylene lauryl ether (indicated as r in Table 6) as the surfactant (R), and 10 wt. % Aqueous solution was used. In the case where the coating layer (C) is provided on one surface of the film, the surface is the A surface. At that time, when the film configuration was a two-layer configuration of A / B, the coating layer (C) was provided on the surface of the polyester layer (A), and the surface was defined as the A surface. When coating layers (C) were provided on both surfaces of the film, they were designated as A and B surfaces, respectively.

[0145] Next, the both ends of the dried film were held with clips and guided to a tenter. In an atmosphere heated to 120 ° C, the direction perpendicular to the longitudinal direction (lateral direction) was multiplied by 3.7. Stretched. Thereafter, heat setting was performed at 210 ° C in a tenter, and the mixture was cooled to room temperature to obtain a biaxially stretched film. Table 10 shows the physical properties of the obtained film as a reflector substrate. Izu Even so, the antistatic property was good on at least one film surface.

[0146] Table 8 shows the types and contents of light stabilizers. Silica, barium sulfate, titanium dioxide, and polymethylpentene contained in the film all formed V and fine bubbles in the film.

[0147] [Comparative Examples 1, 2, 3]

Using the raw materials listed in Tables 1 to 3, a film was formed in the same manner and conditions as in Example 1. With the addition of a light stabilizer! /, It was inferior in durability.

[0148] [Comparative Examples 4, 5]

Using the raw materials listed in Tables 1 to 3, a film was formed in the same manner and conditions as in Example 1. Since no light stabilizer was added, the durability was low and the amount of incompatible thermoplastic resin was small, so the reflectance was low.

[0149] [Comparative Example 6]

Using the raw materials listed in Tables 4 to 6, films were formed in the same manner and conditions as in Example 20. Since the particle diameter of titanium dioxide, which is an inorganic particle, is small, fine bubbles are not generated and the reflectance is low.

[0150] [Comparative Examples 7, 8]

Using the raw materials listed in Tables 4 to 6, films were formed in the same manner and conditions as in Example 20. Since the particle diameter of titanium dioxide, which is an inorganic particle, is large, the bubbles are large, resulting in low reflectivity.

[0151] [Comparative Example 9]

Using the raw materials listed in Tables 4 to 6, films were formed in the same manner and conditions as in Example 20. Since the content of inorganic particles is small and the total thickness is thin, the number of bubbles is reduced, resulting in low reflectivity.

[0152] [Comparative Example 10]

Using the raw materials listed in Tables 4 to 6, films were formed in the same manner and conditions as in Example 20. The content of inorganic particles is sufficient, but the total thickness is thin, so the number of bubbles is reduced, resulting in low reflectivity.

[0153] [Comparative Examples 11 and 12] Using the raw materials listed in Tables 4-6, a film was formed under the same conditions as in Example 20. However, because the copolymerization rate was low, the film was frequently cut during film formation, and the sample could not be prepared.

Yes

[Comparative Example 13]

Using the raw materials listed in Tables 4 to 6, films were formed in the same manner and conditions as in Example 20. Because the light stabilizer was added! /, It was inferior in durability.

[0155] [Table 1]

Table 2

Esther "WTST

PET: Polyethylene terephthalate, PEN: Polyethylene naphthalate

Light stabilizer a Malonic acid ester yarn light stabilizer ('剤 -CAP ")

b Malonic acid ester light stabilizer ("PR-25")

c Triazine light stabilizer ("CGX006")

d Benzophenone light stabilizer (LA-51 ")

Table 3

¾ D¾0154I

(G) Side A side on one side of film

SU517 4-1

Table 4-2

Table 5— 1

Esther T§7

PET: Polyethylene terephthalate, PEN: Reethylene naphthalate, NDC: Naphthalene carbonate ΙΡΑ: Isophthalic acid, CHDM: Cyclohexane Methanol

SU D¾6051I [0161] [Table 5-2]

Polyester layer (B)

Copolymerization 7 K polyester PEN silica

Layer structure Copolymerization Copolymerization Average Average

Content Content Content Content Content Main skeleton component Particle size Material Particle size Type m) mm (mol%) (parts by weight) (parts by weight) (parts by weight) (Um) (parts by weight) (Um) (Parts by weight) Comparative example 6 B / A / B PET NDC 10 92.45-0.05 0.8 Titanium dioxide 7.5 0.05--22.5 Comparative example 7 A / B PET NDC 10 92.5---Titanium dioxide 7.5 10.0 1-1 5 Comparative example 8 A / B PET NDC 10 92.5---Titanium dioxide 7.5 10.0--45 Comparative example 9 B / A / B PET IPA 1 2 96.95-0.05 3.2 Barium sulfate 3.0 1.5--3 Comparative example 10 B / A / B PET NDC 10 92.45-0.05 3.2 Titanium dioxide 7.5 1.5--3 Comparative example 1 1 B / A / B PET IPA 0.5 96.95-0.05 3.2 Barium sulfate 3.0 1.5--1 5 Comparative example 12 B / A / B PET CHDM 8 91.95-0.05 3.2 Calcium carbonate 5.0 1.2 Light stabilizer a 3.0 54 Comparative example 13 A only-----―---

PET: Polyethylene terephthalate, PEN: E-J ethylene naphthalate, NDC: Naphthalene carbonate, IPA: Isophthalate, CHDM: Cyclohexane di-methanol

[0162] [Table 6-1]

Only one side of C film is side A.

When the film configuration was a two-layer configuration of A / B, the coating layer (C) was provided on the surface of the layer (A), and the surface was defined as the A plane. When the coating layer (C) was provided on both surfaces of the film, they were designated as A side and B side, respectively.

[0163] [Table 6-2] Whole film

Large particle size Solid particle other than large particle size Layer structure Thickness Average Average Content Content

Ψί quality Particle size Material Particle size

(U n) (parts by weight) (W m) (parts by weight) (/ im) Example 21 B / A / B 150 Silica 0.01 1 3.2 Titanium dioxide 23.7 1.5 Example 22 B / A / B 1 50 Dioxide 23.7 1.5 ---Titanium

Example 23 B / A / B 150 Silica 0.01 1 3.2 Barium sulfate 31.9 1.2 Example 24 B / A / B 150 Silica 0.01 1 3.2 Barium sulfate 31.9 1.2 Example 25 B / A / B 150 Silica 0.01 1 3.2 Barium sulfate 31.9 1.2 Example 26 B / A / B 150 Silica 0.01 1 3.2 Barium sulfate 31.9 1.2 Example 27 B / A / B 150 Silica 0.01 1 3.2 Barium sulfate 31.9 1.2 Example 28 B / A / B 150 Silica 0.01 1 3.2 Sulfuric acid Barium 31.9 1.2 Example 29 B / A / B 150 Silica 0.01 1 3.2 Barium sulfate 31.9 9 Sulfuric acid

Example 30 B / A / B 150 31.9 1.2---Barium

Example 31 B / A / B 150 Silica 0.046 3.2 Barium sulfate 31.9 9 1.2 Example 32 B / A / B 150 Silica 0.01 1 5.0 Barium sulfate 31.9 9 1.2 Example 33 B / A / B 150 Silica 0.01 1 3.2 Barium sulfate 31.9 1.2 Example 34 B / A / B 170 Silica 0.01 1 3.2 Barium sulfate 33.7 1.5 Example 35 B / A / B 1 70 Sulfuric acid 33.7 1.5---Barium

Example 36 A / B 150 Silica 0.036 3.2 Titanium dioxide 23.7 1.5 Example 37 A / B 1 50 Dioxide 23.7 1.5---Titanium

Example 38 A / B 1 50 Silica 0.036 3.2 Barium sulfate 33.8 1.2 Example 39 A / B 1 50 Silica 0.036 3.2 Barium sulfate 33.8 1.2 Example 4C A / B 150 Silica 0.036 3.2 Barium sulfate 33.8 1.2 Example 41 A / B 150 Silica 0.036 3.2 Barium sulfate 33.8 1.2 Example 42 A / B 150 Silica 0.036 3.2 Barium sulfate 33.8 1.2 Example 43 A / B 150 Silica 0.036 3.2 Barium sulfate 33.8 1.2 Sulfuric acid

Example 44 A / B 150 33.8 1.2 One--Barium

Example 45 A / B 150 Silica 0.014 3.2 Barium sulfate 33.8 1.2 Example 46 A / B 150 Silica 0.36 3.2 Barium sulfate 33.8 1.2 Example 47 A / B 150 Silica 3.6 3.2 Barium sulfate 33.8 1.2 Example 48 A / B 150 Silica 0.036 5.0 Barium sulfate 33.8 1.2 Example 49 B / A / B 150 Silica 0.01 1 3.2 Barium sulfate 31.9 1.2 Example 50 B / A / B 150 Silica 0.01 1 3.2 Barium sulfate 31.9 1.2 Example 51 B / A / B 150 Silica 0.01 1 3.2 Barium sulfate 31.9 1.0 Sulfuric acid

Example 52 B / A / B 180 30 3.8 Silica 0.01 1 3.2 Barium

Example 53 A only 120 Silica 0.05 3.2 Barium sulfate 45 1.2 Comparative example 6 B / A / B 150------Dioxide

Comparative Example 7 A / B 50 23.7 10---Titanium

Comparative Example 8 A / B 150 Dioxide 23.7 10 One--Titanium

Comparative Example 9 B / A / B 20 Silica 0.01 7 3.2 Barium sulfate 7.6 1.3 Comparative Example 10 B / A / B 20 Silica 0.01 7 3.2 Titanium dioxide 23.7 1.5 Comparative Example 1 1 B / A / B 150 Silica 0.01 1 3.2 Barium sulfate 31 .9 1.3 Comparative Example 12 B / A / B 270 Silica 0.036 3.2 Calcium carbonate 30.1 1.2 Comparative Example 13A only 150---Barium sulfate 50 1.5 Where the layer (C) is provided on one side of the film, The f¾ plane was designated as the A plane.

When the film configuration was a two-layer configuration of A / B, the coating layer (C) was provided on the surface of the layer (A), and the surface was designated as the A surface. When the coating layer (C) was provided on both surfaces of the film, they were designated as A side and B side, respectively. [0164] [Table 7]

NDC: Naphthalene Carpon

Light Stabilizer a: Malonic acid ester light stabilizer ("B-CAP") b: Malonic acid ester light stabilizer ("PR-25") c: Triazine light stabilizer ("CGX006) d: Benzophenone Light stabilizer ("LA-51")

[0165] [Table 8] Polyester SA Polyester 瞎 B Whole film Light stabilizer Light stabilizer Light stabilizer

Content Content Content Type Type Type

(Wt%) (wt%) (wt%)

NDC, NDC, NDC, Example 21 38.6 18.8 32.7 Titanium dioxide Titanium dioxide Titanium dioxide

NDC, NDC, NDC ;, Example 22 38.6 18.8 32.7 Titanium dioxide Titanium dioxide Titanium dioxide Example 23--Light stabilizer a 1.0 Light stability S a 0.2 Example 24 1-Light stabilizer a 3.0 Light stability a 0.6 Example 25-One Light Stabilizer a 5.0 Light Stabilization ^ a 1.0 Example 26--Light Stabilizer b 3.0 Light Stabilization ^ b 0.6 Example 27--Light Stabilizer c 3.0 Light Stabilization ^ c 0.6 Example 28--Light Stabilization Agent d 3.0 Light Stable ^ d 0.6 Example 29--NDC 8.9 NDC 1.8 One-NDC 8.9 NDC 1.8 Example 31 One-NDC 8.9 NDC 1.8 Example 32 One-NDC 8.9 NDC 1.8 Example 33 One-NDC 8.9 NDC 1.8 Example 34--NDC 8.9 NDC 2.1 Example 35--NDC 8.9 NDC 2.1

NDC. NDC, NDC, Example 36 38.6 18.8 32.7 Titanium dioxide Titanium dioxide Titanium dioxide

NDG, NDC, NDC, Example 37 38.6 18.8 32.7 Titanium dioxide Titanium dioxide Titanium dioxide

Light stabilizer a, Example 38 Light stabilizer a 3 NDC 4.5 3.4

NDC

Light stabilizer b, Example 39 Light stabilizer b 3 NDC 4.5 3.4

NDC

Example 40 Light Stabilizer c 3 NDC 4.5 Light Stabilizer c, 3.4

NDC

Light stabilizer d, Example 41 Light stabilizer d 3 NDC 4.5 3.4

NDC

Example 42 NDC 8.9 NDC 4.5 NDC 7.8 Example 43 NDC 17.7 NDC 4.5 NDC 14.4 Example 44 NDC 8.9 NDC 4.5 NDC 7.8 Example 45 NDC 8.9 NDC 4.5 NDC 7.8 Example 46 NDC 8.9 NDC 4.5 NDC 7.8 Example 47 NDC 8.9 NDC 4.5 NDC 7.8 Example 48 NDC 8.9 NDC 4.5 NDC 7.8 Example 49--Light Stabilizer a 3.0 Light Stabilizer a 0.6 Example 50--Light Stabilizer a 3.0 Light Stabilizer a 0.6 Example 51--NDC 8.9 NDC 1.8 Example 52 1-NDC 8.9 NDC 1.5 Example 53 Light stabilizer a 3--Light stabilizer a 3.0

NDC, NDC, NDC, Comparative Example 6 38.6 18.8 32.7 Titanium dioxide Titanium dioxide Titanium dioxide

NDG, NDC, NDC, Comparative Example 7 38.6 18.8 32.7 Titanium dioxide Titanium dioxide Titanium dioxide

NDC, NDC, NDC, Comparative Example 8 38.6 18.8 32.7 Titanium Dioxide Titanium Dioxide Titanium Dioxide Comparative Example 9------

Comparative example 10 38.6 18.8 32.7 Titanium dioxide Titanium dioxide Titanium dioxide Comparative example 1 1--NDC 8.9 NDC 1.8 Comparative example 12--Light stabilizer a 3.0 Light stabilizer a 1.2 Comparative example 13--- ---

NDC: Naphthalene dicarboxylic acid

: Agent a: Malonic acid ester light stabilizer ("B-CAP":

b: Malonic acid ester light stabilizer ("PR-25")

c Tenriadine light stabilizer ("CGX006")

d: Benzophenone light stabilizer ("LA-51") s [Saint 061

Dgo68l01

goll67l01l Table 10-2

Industrial applicability

[0169] The present invention is suitably used as a substrate for a reflective film that requires light resistance and dust removal performance.

Brief Description of Drawings

[0170] FIG. 1 is a conceptual diagram of a luminance measurement system.

Explanation of symbols

[0171] 11.Fluorescent tube

12.Reflective film

13.Light guide plate

14.Diffusion film

15.Luminance meter

Claims

The scope of the claims

[1] A white polyester film for a reflection plate of a liquid crystal display, which contains a light stabilizer in a polyester film having fine bubbles and has an average reflectance of 97% or more on at least one surface of the film.

[2] The liquid crystal display reflection according to claim 1, wherein the polyester film has a structure in which a polyester layer (B) containing a light stabilizer is laminated on at least one side of a polyester layer (A) having fine bubbles. White polyester film for board.

[3] The layer (C) containing an antistatic agent is applied to at least one surface of the polyester film, and the surface specific resistance value of the layer (C) is IX 10 ¹³ Ω / mouth or less. Polyester film for LCD display reflectors.

[4] The white polyester normalinolem for a liquid crystal display reflector according to claim 1, wherein the center plane average roughness Ra of the polyester film surface is 0.1 or more and the ten-point average roughness Rz is 1.0 or more.

[5] The white polyester film for a liquid crystal display reflector according to claim 1, wherein the content of the light stabilizer contained in the polyester film is 0.02% by weight or more and 20% by weight or less based on the total weight of the polyester film. .

[6] The white polyester film for a reflective plate of a liquid crystal display according to [1], which is a malonate-based light stabilizer contained in the polyester film.

7. The white polyester film for a liquid crystal display reflector according to claim 1, which is a light stabilizer strength 2,6-naphthalenedicarboxylic acid or a copolymer thereof contained in the polyester film.

[8] The white for liquid crystal display reflectors according to [1], wherein the polyester film contains titanium dioxide particles, and the content thereof is 1% by weight or more and 40% by weight or less based on the total weight of the polyester film. Polyester film.

[9] The polyester film contains particles having an average particle size of 1.0, 1 m or more (hereinafter referred to as large particle size particles), and the content thereof is 0.01% by weight with respect to the total weight of the polyester film. The white polyester film for a liquid crystal display reflector according to claim 1, wherein the content is 5% by weight or less.

10. The polyester film for a liquid crystal display reflector according to claim 9, wherein the large particle size is a silica particle.

[11] The white polyester film for a liquid crystal display reflector according to [1], wherein the polyester film contains a thermoplastic resin incompatible with polyester to form fine bubbles.

[12] The thermoplastic resin incompatible with the polyester is polymethylpentene, the average particle size in the polyester film is equal to or less than the average particle size of the large particles, and is based on the total weight of the polyester film. The white polyester film for a liquid crystal display reflector according to claim 11, which is contained in an amount of 5 wt% or more and 25 wt% or less.

[13] The white polyester film for a liquid crystal display reflector according to [11], wherein the specific gravity of the polyester film is 0.5 or more and 1.2 or less.

14. The white polyester film for a liquid crystal display reflector according to claim 1, wherein fine bubbles are formed when the polyester film contains inorganic particles.

[15] The inorganic particles contained in order to form the fine bubbles are barium sulfate, and the barium sulfate has an average particle size of 0.1, 1 m or more and 5.0, 1 m or less and a large particle size. 15. The white polyester film for a liquid crystal display reflector according to claim 14, wherein the white polyester film is not more than the average particle diameter of the particles and contains 5 to 70% by weight based on the total weight of the polyester film.

16. The white polyester film for a liquid crystal display reflector according to claim 14, wherein the specific gravity of the polyester film is 1.2 or more and 1.4 or less.

[17] The white polyester film for a liquid crystal display reflector according to claim 2, wherein the core layer portion is the polyester layer (A) and the surface layer portion on one or both sides is the polyester layer (B). .