JP2001264534A - Optical film and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a transparent film can not be obtained due to deterioration of compatibility of resin and the like and a mixing ratio is limited and sufficient orientation control is disturbed, in an orientation controlling method using a mixed resin. SOLUTION: The optical film having transparent properties of <=1.5% haze and controlled orientation can be obtained by melting and kneading plural kinds of resins to form the mixed resin before a resin solution is prepared, then dissolving the mixed resin to form the resin solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical film used for a movable electrode substrate of a touch panel, and an optical film.

[0002]

2. Description of the Related Art A liquid crystal display element has attracted attention as an image display element, and has been applied to portable electronic notebooks, information terminals, and the like as its use. As an input device to these portable information terminals, a device in which a transparent resistive touch panel is mounted on a liquid crystal display element is used. The resistive touch panel has a structure in which a movable electrode substrate and a fixed electrode substrate are opposed to each other using a dot spacer while forming a gap so that the substrate surfaces do not normally contact each other. Further, with the rapid spread of portable information terminals in recent years, functions such as improvement of display contrast and prevention of external light reflection have been required in addition to reduction in thickness and weight of the device itself. In response to such a request, for example, Japanese Patent Laid-Open No. 10-4
As disclosed in Japanese Patent Application Laid-Open No. 8625 or JP-A-11-115086, a touch panel is disposed between a liquid crystal display-side polarizing plate and a liquid crystal cell of a liquid crystal display device to improve the contrast of the entire display device, 1 /
A method of preventing external light reflection by providing a function of a four-wavelength plate has been proposed. As the movable electrode substrate having the function of a quarter-wave plate, a structure in which a polymer film having a phase difference of 波長 wavelength is bonded to the opposite surface of a glass plate processed with a transparent conductive material, or a phase difference of 波長A configuration in which a transparent conductive film is directly applied to a polymer film having a wavelength is known. However, the latter movable electrode substrate integrated with a phase difference is particularly preferred because of ease of pen input. A polymer film used for a movable electrode substrate with an integrated retardation is required to have a uniform retardation over the entire surface. For this purpose, a polymer film obtained by forming an amorphous polymer by a solution casting method and stretching the film is used. As the amorphous polymer, polycarbonate, polysulfone, polyarylate, polyvinyl alcohol, triacetyl cellulose and the like are generally known.

Further, a polymer film for a movable electrode substrate with an integrated retardation is required to have heat resistance so that the optical characteristics do not change by heat treatment during the process of processing into a touch panel. And polysulfone.

However, polyallylate and polysulfone formed by a solution casting method are apt to be oriented, and molecular chains have already been aligned over the entire surface of the film. When longitudinal uniaxial stretching is performed on such a film,
Since relaxation in the width direction occurs at the same time, shrinkage in the width direction actually occurs more than the stretching ratio. Therefore, even if the temperature is slightly uneven, the film may be loosened or meandering, and it is difficult to obtain a wide and long retardation film having a width exceeding 1 m. A method of controlling the orientation by adding an additive such as a plasticizer to such a problem is generally known, but when forming a conductive film in a vacuum, a bleed-out of a plasticizer or the like causes a vacuum system. There is a risk of contaminating the inside. Therefore, Japanese Patent Application Laid-Open No. 5-297219 proposes a method of controlling the orientation by mixing another resin.

[0005]

However, in the method of controlling the orientation by mixing another resin, a transparent film cannot be obtained due to deterioration of the compatibility of the resin, and the mixing ratio is limited. If a mixing ratio that hinders the control or that a conversely sufficient orientation control effect is applied is applied, the transparency of the film deteriorates, and there is a problem that the film is not used as an optical film.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems. That is, before preparing the resin solution, melt-kneading a plurality of types of resin in advance to form a mixed resin,
By dissolving the mixed resin to form a resin solution, it was found that the optical film obtained thereby had a surprising transparency of 1.5% or less in haze, and that the orientation was controlled. .

Accordingly, a first aspect of the present invention is to provide a polyarylate resin of 95 to 30 parts by weight and a polycarbonate resin of 5 to 70 parts by weight.
And a step of melt-kneading the mixed resin so that the total amount becomes 100 parts by weight to obtain a mixed resin, and a step of forming the mixed resin into a film by a solution casting method. The method may include a stretching step.

The second aspect of the present invention is that a polyarylate resin is 95 to 30 parts by weight and a polycarbonate resin is 5 to 70 parts by weight.
Part by weight of the polymer film, wherein the total amount is 100 parts by weight, and the haze is 1.5% or less.

A third aspect of the present invention relates to a transparent conductive film for a touch panel using the above optical film.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION
It is characterized by using a mixed resin obtained by mixing 30 parts by weight of a polyarylate resin and 5 to 70 parts by weight of a polycarbonate resin so that the total amount becomes 100 parts by weight. Further, when a film is formed by using a mixed resin that is melt-kneaded and mixed, a transparent film having a haze of 1.5% or less can be obtained.

The preferred mixing ratio is from 95 to 30 parts by weight of the polyarylate resin to 5 to 30 parts of the polycarbonate resin.
70 parts by weight, more preferably 10 to 65 parts by weight, more preferably 90 to 35 parts by weight, particularly preferably 15 to 60 parts by weight to 85 to 40 parts by weight. An optical film whose orientation is controlled in the range of these mixing ratios and which satisfies the heat resistance required when processing the optical film into a touch panel or the like can be obtained.

The polyarylate resin used in the present invention can be obtained by known methods, for example, JP-A-3-56903, JP-A-3-122602, JP-A-3-124463, and JP-A-3-155502. As described, it is obtained from a polymer or copolymer of terephthalic acid and / or isophthalic acid with at least one bisphenol and dihydroxybiphenyl, and a plurality of kinds of polyarylate resins can be used.

As preferred bisphenols for obtaining the polyarylate resin used in the present invention, 2,2-
Bis (4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-di-sec-butyl-4)
-Hydroxyphenyl) propane, 2,2-bis (3,
5-di-tert-butyl-4-hydroxyphenyl)
Propane, bis (4-hydroxyphenyl) methane, bis (3,5-dimethyl-4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane,
1,1-bis (3,5-dimethyl-4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane , Screw (4
-Hydroxyphenyl) ketone, bis (3,5-dimethyl-4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) ether, bis (3,5-dimethyl-
4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfide, bis (3,5-dimethyl-
4-hydroxyphenyl) sulfide, 2,2-bis (4-hydroxyphenyl) hexafluoropropane,
2,2-bis (3,5-dimethyl-4-hydroxyphenyl) hexafluoropropane, 2,2-bis (3,5
-Dimethoxy-4-hydroxyphenyl) propane, bis (3,5-dimethoxy-4-hydroxyphenyl) methane, 2,2-bis (3-methoxy-4-hydroxy-
5-methylphenyl) propane, bis (3-methoxy-
4-hydroxy-5-methylphenylmethane, bis (3,5-diphenyl-4-hydroxyphenyl) methane, 2,2-bis (3,5-diphenoxy-4-hydroxyphenyl) propane, bis (3-phenoxy- 4-
Hydroxy-5-methyl) methane, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxy-3-ethylphenyl) sulfone, bis (4-hydroxy-3,
5-diethylphenyl) sulfone, bis (4-hydroxy-3,5-dimethoxyphenyl) sulfone, bis (4
-Hydroxy-3,5-diethoxyphenyl) sulfone.

Preferred dihydroxybiphenyls for obtaining the polyarylate resin used in the present invention include 4,4'-dihydroxybiphenyl and 4,4 '
-Dihydroxy-3,3 ', 5,5'-tetramethylbiphenyl, 4,4'-dihydroxy-3,3', 5,5
'-Tetraethylbiphenyl.

The polyarylate resin polymerized by using the above reaction components is as shown in the following general formula (1).

[0016]

Embedded image

Next, the polycarbonate resin used in the present invention will be described. The polycarbonate resin can be obtained by a known method, and the polycarbonate resin which can be preferably used in the present invention is made of bisphenols. Examples of the bisphenols include 2,2-bis (4
-Hydroxyphenyl) propane, 2,2-bis (3,
5-dimethyl-4-hydroxyphenyl) propane,
2,2-bis (3,5-di-sec-butyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, bis (4- Hydroxyphenyl) methane, bis (3,5-dimethyl-4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane,
1,1-bis (3,5-dimethyl-4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane , Screw (4
-Hydroxyphenyl) ketone, bis (3,5-dimethyl-4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) ether, bis (3,5-dimethyl-
4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfide, bis (3,5-dimethyl-
4-hydroxyphenyl) sulfide, 2,2-bis (4-hydroxyphenyl) hexafluoropropane,
2,2-bis (3,5-dimethyl-4-hydroxyphenyl) hexafluoropropane, 2,2-bis (3,5
-Dimethoxy-4-hydroxyphenyl) propane, bis (3,5-dimethoxy-4-hydroxyphenyl) methane, 2,2-bis (3-methoxy-4-hydroxy-
5-methylphenyl) propane, bis (3-methoxy-
4-hydroxy-5-methylphenylmethane, bis (3,5-diphenyl-4-hydroxyphenyl) methane, 2,2-bis (3,5-diphenoxy-4-hydroxyphenyl) propane, bis (3-phenoxy- 4-
Hydroxy-5-methyl) methane, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxy-3-ethylphenyl) sulfone, bis (4-hydroxy-3,
5-diethylphenyl) sulfone, bis (4-hydroxy-3,5-dimethoxyphenyl) sulfone, bis (4
-Hydroxy-3,5-diethoxyphenyl) sulfone. Among them, polycarbonate derived from 2,2-bis (4-hydroxyphenyl) propane is preferably used from the viewpoint of availability of raw materials. The polycarbonate resin composed of bisphenols exemplified here is represented by the following general formula (2)

[0018]

Embedded image

## EQU1 ##

Next, a method of melt-kneading the polyarylate resin and the polycarbonate resin will be described. For melt kneading, various blenders such as an extruder, a hot roll, and a Banbury mixer may be used, and if a general melt kneading method is used, the effects of the present invention can be obtained, which is preferable from the viewpoint of productivity. The temperature at which the melt-kneading is performed depends on the melting point of the resin to be mixed,
What is necessary is just to determine suitably with reference to thermal stability.

When the mixed resin obtained by the above method is formed into a film, the optical film of the present invention can be obtained. This film formation can be performed by various known methods, for example, a melt extrusion method,
An inflation method, a solution casting method, or the like is used. Among these, a solution casting method is particularly preferred as a film forming method. With the solution casting method, a resin solution obtained by dissolving a resin in an organic solvent is cast on a support by a method such as coating or casting, and then dried to obtain a self-supporting film. It is a method to obtain a plastic film by peeling it off and then drying it if necessary, but this method has no defects such as die lines,
In addition, an optically isotropic film having high film thickness accuracy and small retardation value can be obtained. In addition, when a plastic film made of a mixed resin in which a plurality of resins are mixed is obtained by a solution casting method, a method of blending the resins at the time of dissolution in an organic solvent is general, whereas the production method of the present invention It is characterized in that a mixed resin melt-kneaded in advance is dissolved in a solution. The optical film obtained by the method of the present invention has extremely excellent transparency. The organic solvent used for the solution casting method may be appropriately selected with reference to the boiling point and the solubility of the resin.

Although the thickness of the optical film of the present invention is not particularly limited, it is generally 30 to 150 μm, preferably 5 to 150 μm.
When the thickness is in the range of 0 to 100 μm and the touch panel is used, an optical film having no problem at the time of input can be obtained.
The optical film of the present invention may be blended with various additives and plasticizers as necessary, and the blending may be performed at the time of melt-kneading or at the time of preparing a resin solution.

Hereinafter, the transparent conductive film for a touch panel of the present invention will be described. The optically isotropic film obtained above can be subjected to an orientation treatment by a known stretching method to give a uniform retardation. By uniaxial or biaxial stretching, orient the polymer in the film plane,
It is also possible to control the three-dimensional refractive index of the film by performing a special stretching as described in JP-A-5-157911. By such processing, it is possible to provide an anti-reflection function, reduce the viewing angle dependence of display quality, and provide a color compensation function when combined with a super twisted nematic (STN) liquid crystal display device. A suitable phase difference value is 30 nm to 2000 nm, but more preferably depends on the intended function, and an optimum phase difference value may be selected for each. For example, when an anti-reflection function is provided, it is desirable to select a phase difference value from 50 nm to 250 nm. When a color compensation function in combination with an STN liquid crystal display device is provided, the phase difference value is set to 400 n.
It is desirable to select in the range of m to 600 nm.

The surface of the optical film of the present invention can be subjected to a corona treatment as required. In particular, when the film surface is subjected to surface treatment such as coating,
When another substrate is laminated with an adhesive, corona treatment of the film surface is a suitable method as a means for increasing mutual adhesion. Further, the optical film of the present invention may be subjected to a surface coating treatment on one or both sides of the film, if necessary, for the purpose of imparting solvent resistance or improving the adhesion of the transparent conductive layer. Illustrative examples of preferred coating layers include, as organic coating layers, melamine resin-based, acrylic resin-based, urethane resin-based, alkyd resin-based, and fluorine-containing resin-based systems.Organic-silicone composite systems include polyester polyols and the like. Examples thereof include those obtained by blending a partially hydrolyzed product of an alkyl trialkoxy silane and a tetraalkoxy silane with etherified methylol melamine. Further, silicone-based materials such as partial hydrolysates of aminosilane and epoxysilane, partial hydrolysates of silane coupling agents and alkyltrialkoxysilanes / tetraalkoxysilanes, and hydrolysates of colloidal silica and alkyltrialkoxysilanes are also suitable. Can be used. After coating these materials on one or both sides of the optical film of the present invention, a film having a solvent-resistant film can be formed by thermosetting. At this time, simultaneous use of a low-temperature curing type catalyst is a preferable method for suppressing undesired thermal deformation of the film. A cured layer obtained by adding a photoinitiator to a monomer or oligomer such as a polyfunctional acrylate and using ultraviolet rays or an electron beam can also be suitably used. Various fillers can be added to the coating layer as needed. By adding the filler, it is possible to prevent generation of an undesirable Newton's ring due to light interference between the electrodes and blocking between the electrode substrates. Preferred fillers include organic fillers such as polymethacrylic acid esters, polyacrylic acid esters, polyolefins, polystyrenes, divinylbenzenes, benzoguanamines, and organic silicones, and inorganic fillers such as silica, alumina, and titanium oxide. Can be used.

In addition, an inorganic material made of a metal oxide such as silicon oxide or silicon nitride or a metal nitride can also be used as a suitable coating layer. These ceramic layers are obtained by applying and curing a reactive inorganic coating agent. A preferable example of such a reactive inorganic coating agent is a polysilazane-based inorganic polymer.
The inorganic polymer can be obtained by a method described in JP-A-1-203476 and the like. Also, Japanese Patent Application Laid-Open No. 6-24
As described in JP-A No. 0208 and JP-A-6-122852, polysilazane obtained by partially modifying the polymer with a compound having active hydrogen such as alcohol can also be suitably used. The inorganic polymer layer formed on the surface gives a hard solvent-resistant inorganic thin film by heat curing. That is, by heating and baking in a chemically inert atmosphere such as nitrogen or argon, a silicon nitride-like thin film is provided. In addition, baking in the presence of oxygen or water vapor gives a silicon oxide-like thin film.

Further, if necessary, a layer having gas barrier properties can be formed. In particular, imparting a water vapor barrier property is preferable because dew condensation between the touch panel movable electrode and the fixed electrode can be prevented. If condensation occurs, conduction between the electrodes occurs at the condensation area,
It may cause touch panel malfunction.

Examples of the organic material-based gas barrier layer include acrylonitrile-based polymers such as polyacrylonitrile, acrylonitrile-methyl acrylate copolymer and acrylonitrile-styrene copolymer, polyvinylidene chloride, polyvinyl alcohol, vinyl alcohol-ethylene. A layer made of an organic polymer material such as a vinyl alcohol polymer such as a copolymer can be used. These materials can be used as a gas barrier layer on the optical film of the present invention by a wet coating method using a gravure coater or a reverse coater.

As the inorganic gas barrier layer,
Silicon dioxide or a compound containing the same as a main component and containing at least one metal oxide such as silicon monoxide and aluminum oxide, and / or silicon nitride or a metal nitride containing the same as a main component and aluminum nitride or the like A compound containing at least one compound can be used, and specific examples of the compound include, for example, SiO _x and SiAlN. Among the inorganic barrier thin films, ie, metal oxides mainly composed of silicon oxide and / or metal nitrides mainly composed of silicon nitride, SiO _x , especially x
Is preferably 1.3 to 1.8, more preferably 1.5. These inorganic barrier layers are formed by physical vapor deposition (PVD) such as sputtering or electron beam evaporation.
Alternatively, a film can be formed by chemical vapor deposition (CVD). Alternatively, an organic metal compound layer such as polysilazane may be formed on the film of the present invention and then thermally decomposed.

These barrier layers may be used alone or in combination of two or more. In particular, when an organic barrier layer and an inorganic barrier layer are used in combination, the excellent resistance of the organic barrier layer to crack pinholes in the barrier layer and the excellent resistance of the inorganic barrier layer to water vapor in particular provide a synergistic effect. This is a particularly preferred combination. At this time, an anchor coat layer can be provided between the layers for the purpose of improving the adhesion between the layers. As the anchor coat layer, a siloxane-based cured product such as polydimethylsiloxane or a urethane- or epoxy-based cured product layer is suitably used. The method for forming these cured product layers is not particularly limited, and a thermosetting method, an ultraviolet curing method, or an electron beam curing method can be used.

The transparent conductive film for a touch panel of the present invention does not need to be provided with all of these coating layers, and the type and the configuration are appropriately selected depending on the purpose.

The transparent conductive film for a touch panel has a transparent conductive layer formed on at least one surface to form a movable electrode substrate for a touch panel.

The transparent electrode layer is preferably a metal oxide mainly composed of indium oxide. Depending on the purpose, the layer may be formed directly on the film of the present invention, or may be formed on the gas barrier layer or the solvent-resistant coating layer. May be formed on the intermediate layer. The metal oxide containing indium oxide as a main component is indium oxide or a main component thereof, specifically, 80% (% by weight, the same applies hereinafter) or more, further containing 90 to 95%, tin oxide,
One or more other metal oxides such as cadmium oxide
%, More preferably 5 to 10%. Specific examples of this compound include ITO and CdIn ₂ O ₄ . Among the metal oxides mainly composed of indium oxide, ITO, especially tin in terms of metal, is 1%.
0% or less, preferably 5 to 10% is preferable in that high transparency can be obtained.

As a method of forming these transparent electrode layers, D
It is produced using a method such as C magnetron sputtering, EB vapor deposition, and CVD. Among them, DC magnetron sputtering is particularly preferably used in view of resistance stability and adhesion to a film. A preferred resistance value of the transparent conductive layer is 1 Ω / □ to 1000 Ω / □, more preferably 10 Ω / □ to 600 Ω / □. Further, the light transmittance is preferably 85% or more.

As described above, a coating layer for imparting various functions such as solvent resistance, gas barrier properties, and transparent conductivity may be directly formed on the optical film of the present invention. It is also possible to laminate another film directly with the optical film of the present invention or via an adhesive.

The movable electrode substrate thus obtained is
Since a pressure is applied to the touch panel via the polarizing plate, when the substrate is thick, the pressure required for input increases, and an input error is likely to occur, which is not preferable. Generally,
30 to 150 μm, preferably 50 to 100 μm
It is. Further, the light transmittance is preferably 85% or more.

Further, when combined with a display device due to the surface properties of the coating layer, an undesired glare may appear on a displayed image. JI for glare
It shows a close correlation with the transmitted image clarity described in SK7105-1981, 6.6. The larger the transmitted image clarity, the less the glare. Although the preferred transmitted image definition depends on the resolution of the display image, the transmitted image definition measured using a 0.25 mm slit is preferably 80% or more, more preferably 85% or more. In order to obtain such a high transmission image definition, it is preferable to lower the pre-drying temperature for forming the coating layer as much as possible. Specifically, it depends on the type and capacity of the drying apparatus, but is generally about 70 ° C. It is desirable to perform the following.

[0037]

EXAMPLES The methods for measuring the physical properties shown in Examples and Comparative Examples are described below. <Measurement method of light transmittance> JIS K7105-19
It was measured by the method described in 5.5 of No. 81. <Method for measuring haze> JIS K7105-1981
Was measured by the method described in 6.4. <Measurement of phase difference> Phase difference meter KOBRAS of Kanzaki Paper
Measurement wavelength 590n by rotating analyzer method using D-21
m and the measurement diameter were 35 mm.

Hereinafter, the present invention will be described specifically with reference to examples.

(Example 1) Polyarylate (U-100 manufactured by Unitika) composed of 2,2-bis (4-hydroxyphenyl) propane and an equal mixture of terephthalic acid and isophthalic acid and a polycarbonate comprising bisphenol A ( Teijin Chemicals C-1400) (mixing ratio: 70 parts by weight, 30 parts by weight, respectively) was added using a twin-screw extruder to 32 parts.
Melt extrusion was performed at 0 ° C. to form pellets. This pellet 1
00 parts by weight were dissolved in 400 parts by weight of methylene chloride. This solution was cast on an endless belt, pre-dried, and then peeled from the support. Using the obtained film having a width of 1500 mm, drying was carried out using a roll-conveying dryer in which a tension roll was arranged. Further, this film was subjected to longitudinal uniaxial stretching at a furnace temperature of 175 ° C. to a thickness of 80 μm.
m, a film having a phase difference of 145 nm was obtained. When the haze of this film was measured, it was 0.4%.

An ITO film was formed on this retardation film by DC magnetron sputtering. Indium oxide to which 10% tin oxide was added was used as a target, and 5%
Film formation was performed in an argon atmosphere to which oxygen was added. When the sheet resistance of this ITO film was measured using a four-probe resistance measuring apparatus, it was 440 ± 10Ω / □.
Furthermore, a touch panel was made by combining with a transparent conductive glass.

Example 2 Polyarylate (U-100 manufactured by Unitika) comprising 2,2-bis (4-hydroxyphenyl) propane and a mixture of terephthalic acid and isophthalic acid in equal amounts and a polycarbonate comprising bisphenol A ( Teijin Chemicals C-1400) (50 parts by weight and 50 parts by weight, respectively) were mixed using a twin-screw extruder.
Melt extrusion was performed at 0 ° C. to form pellets. This pellet 1
Was dissolved in 400 parts by weight of methylene chloride, left at room temperature for 60 minutes, and peeled off.
Drying was performed at 10 ° C. for 10 minutes and then at 200 ° C. for 10 minutes to obtain a film having a thickness of 80 μm. When the haze of this film was measured, it was 0.4%.

Comparative Example 1 Bisphenol A was added to 70 parts by weight of a polyarylate (U-100 manufactured by Unitika) composed of 2,2-bis (4-hydroxyphenyl) propane and a mixture of equivalent amounts of terephthalic acid and isophthalic acid. 30 parts by weight of polycarbonate (C-1400 manufactured by Teijin Chemicals Co., Ltd.) was dissolved in 400 parts by weight of methylene chloride, cast on a SUS plate, left at room temperature for 60 minutes, and peeled off. The film was dried at 140 ° C. for 10 minutes and further at 200 ° C. for 10 minutes to obtain a film having a thickness of 80 μm. The haze of this film was 1.9% when measured.

COMPARATIVE EXAMPLE 2 Bisphenol A was prepared from 50 parts by weight of polyarylate (U-100 manufactured by Unitika) composed of 2,2-bis (4-hydroxyphenyl) propane and a mixture of terephthalic acid and isophthalic acid in equal amounts. Polycarbonate (A2500 manufactured by Idemitsu Petrochemical Co., Ltd.) was dissolved in 400 parts by weight of methylene chloride, cast on a SUS plate, allowed to stand at room temperature for 60 minutes, peeled off, and sandwiched by a four-piece fixing jig at 140 ° C. For 10 minutes and further at 200 ° C. for 10 minutes to obtain a film having a thickness of 80 μm. When the haze of this film was measured, it was 54.2%.

Comparative Example 3 100 parts by weight of a polyarylate (U-100 manufactured by Unitika) composed of 2,2-bis (4-hydroxyphenyl) propane and an equal mixture of terephthalic acid and isophthalic acid was mixed with 400 parts of methylene chloride. It dissolved in parts by weight. This solution is cast on an endless belt,
After predrying, it was peeled off from the support. 15 obtained
Drying was carried out using a roll transport type dryer in which a tension roll was arranged using a film having a width of 00 mm. Further, when this film was subjected to longitudinal uniaxial stretching at a furnace temperature of 200 ° C., the film was loosened and meandered and could not be wound as a roll film.

[0045]

The optical film of the present invention has excellent transparency and its orientation is controlled, so that it does not generate slack or meander during stretching, and is particularly suitable as a transparent conductive film for touch panels. Transparent conductive films for touch panels also have good optical properties.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int. Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09F 9/00 366 G09F 9/00 366A 5G046 H01H 13/00 H01H 13/00 Z 5G435 36/00 36/00 G // B29K 67:00 B29K 67:00 69:00 69:00 F term (reference) 2H049 BA06 BA42 BB44 BC03 4F071 AA48 AA50 AF30Y AH19 BA01 BB02 BB06 BB07 BC01 4F205 AA27A AA27K AA28A AA28K AG01 AH73 GE07 GB07 GC07 4J002 CF16W CG01X CG03X GP00 5G006 AZ05 FB19 FB30 LG01 5G046 AA11 AB02 AE13 5G435 AA00 HH02 HH12 KK07

Claims (7)

[Claims] A total amount of 95 to 30 parts by weight of a polyarylate resin and 5 to 70 parts by weight of a polycarbonate resin is 1
A method for producing an optical film, comprising: a step of obtaining a mixed resin by melt-kneading so as to be 00 parts by weight; and a step of forming the mixed resin into a film by a solution casting method. 2. The method for producing an optical film according to claim 1, comprising a stretching step. 3. A total amount of 95 to 30 parts by weight of a polyarylate resin and 5 to 70 parts by weight of a polycarbonate resin.
An optical film, wherein the polymer film is contained so as to be 00 parts by weight, and has a haze of 1.5% or less. 4. The main component of the polyarylate resin is represented by the following general formula (1). The optical film according to claim 3, which is represented by: 5. The main component of the polycarbonate resin is represented by the following general formula (2). The optical film according to claim 3, wherein the optical film is represented by: 6. The method according to claim 3, which is obtained by the method according to claim 1 or 2.
The optical film described in the paragraph. 7. A transparent conductive film for a touch panel using the optical film according to claim 3. Description: