JPH0895033A - Transparent conductive polarizing film - Google Patents

Abstract

PURPOSE: To reduce the number of films constituting a liquid crystal display when the films are used for the liquid crystal display so as to improve the productivity of the display by providing a function as a transparent conductive film in a polarizing film protecting film at the same time and to provide a film contributing for thinning, lightening in weight, and improvement in lightness. CONSTITUTION: In a transparent conductive polarizing film, protecting films are laminated on both sides of a polarizing plate, and on one of the protecting films, a transparent conductive film is applied, and at least the protecting film to which the transparent conductive film is applied is constructed of such a film as is provided with light ray transmittance of 90% or more, thermal deformation temperature of 100 deg.C or more, water absorption in water at 23 deg.C for 24 hours of 1.0% or less, and surface hardness of H or higher by pencil hardness.

Description

Detailed Description of the Invention

INDUSTRIAL APPLICABILITY In the present invention, since the polarizing film protective film also has the function of a transparent conductive film, the productivity of the display can be improved by reducing the number of films constituting the liquid crystal display, especially when used for the liquid crystal display. The present invention relates to a transparent conductive polarizing film that can be improved, contribute to reduction in thickness and weight, and improvement in brightness.

[0002]

2. Description of the Related Art Liquid crystal displays include liquid crystals, liquid crystal alignment films, transparent electrodes, polarizing films, retardation films, light condensing sheets, diffusion films, light guide plates, light reflecting sheets, and other films having many different functions. It is made up of sheets. Since there are many types of films and sheets,
The assembling process is complicated, there are restrictions on cost reduction, and as the number of laminated layers increases, the light transmittance decreases and the image becomes darker, so there is a strong demand for reducing the number of sheets used. Therefore, as one of attempts to reduce the number of films constituting the display, a technique of directly disposing a specific transparent conductive film on one surface of a protective film laminated on both surfaces of a polarizing film is disclosed by JP-A-57-24904. However, the cellulose-based film such as triacetyl cellulose (TAC), which is mentioned as an example of the polarizing film protective film, is not always satisfactory in durability under high temperature and high humidity, heat resistance, and adhesion. However, the above-mentioned problems have come to be strongly pointed out especially as liquid crystal displays have been adopted as in-vehicle displays. In this way, the protective film has a low birefringence,
Films that meet all of the above required characteristics as the performance of liquid crystal displays progresses, with the demand for performance such as heat resistance, low moisture absorption, high mechanical strength, surface smoothness, and adhesion with adhesives and adhesives. Is desired.

On the other hand, among the films that have been studied as protective films, films made of acrylic resin such as polymethylmethacrylate, polycarbonate resin (PC), polyester resin such as polyethylene terephthalate, etc. in addition to the above-mentioned TAC. It is known that the acrylic resin has a heat distortion temperature of about 90 ° C,
There is a problem that the film is deformed in the process of forming the transparent conductive film. Further, since it has a relatively large water absorption, it has a problem in durability under high temperature and high humidity as in TAC. In addition, the polyester resin is inferior in transparency, and a liquid crystal display using such a film has a problem that it lacks in brightness and is hard to see. The film made of PC has excellent heat resistance and moisture resistance, but the surface hardness is low, so the film is easily scratched, and the film is damaged when the transparent conductive film is formed or during the assembly work of the display, etc.・ There are problems such as loss of transparency. As described above, it has been difficult to obtain a conventionally known film, which satisfies the above-mentioned required characteristics, which is becoming more and more severe especially in liquid crystal display applications.

[0004]

SUMMARY OF THE INVENTION The present invention has solved all of the above-mentioned problems. Even when a transparent conductive film is formed, the film is not deformed, and the durability and transparency at high temperature and high humidity are improved. It is an object of the present invention to provide a transparent conductive polarizing film having excellent properties.

[0005]

In the transparent conductive polarizing film of the present invention, at least the protective film provided with the transparent conductive film has a light transmittance of 90% or more and a heat distortion temperature of 100 ° C.
Above, water absorption rate when placed in 23 ° C water for 24 hours is 1.0
% Or less, and the surface hardness is H or more in terms of pencil hardness. It also provides a transparent conductive polarizing film in which the film is made of a thermoplastic norbornene-based resin. Transparent conductive polarizing film is one of the protective films laminated on both sides of the polarizing film,
Further, a transparent conductive film is formed.

The polarizing film used in the present invention is not particularly limited as long as it has a function as a polarizer. For example, a PVA / iodine-based polarizing film, a dye-based polarizing film in which a dichroic dye is adsorbed and oriented on a PVA-based film, a dehydration reaction is induced from the PVA-based film, or a dechlorination reaction of a polyvinyl chloride film, Polyene-based polarizing film formed with polyene, modified P containing a cationic group in the molecule
Examples thereof include a polarizing film having a dichroic dye on the surface and / or inside of a PVA-based film made of VA.

The method for manufacturing the polarizing film is also not particularly limited. For example, a method of adsorbing iodine ions after stretching the PVA-based film, a method of stretching the PVA-based film after dyeing with a dichroic dye, a method of stretching the PVA-based film after dyeing with a dichroic dye, and a dichroic dye Examples thereof include known methods such as a method of stretching after printing on a PVA-based film and a method of printing a dichroic dye after stretching the PVA-based film. More specifically, iodine is dissolved in a potassium iodide solution to form a higher order iodine ion, which is adsorbed on a PVA film and stretched, and then a 1 to 4% by weight boric acid aqueous solution with a bath temperature of 30. A method for producing a polarizing film by dipping at -40 ° C,
Alternatively, the PVA film is similarly treated with boric acid, stretched uniaxially about 3 to 7 times, and immersed in a 0.05 to 5 wt% dichroic dye aqueous solution at a bath temperature of 30 to 40 ° C. to adsorb the dye. There is a method of producing a polarizing film by drying at 80 to 100 ° C. and heat fixing.

In the transparent conductive polarizing film of the present invention,
The protective film laminated on the polarizing film has a thickness of about 5 mm.
Although a transparent film having an optical uniformity of up to 500 μm and a small retardation can be used, at least a protective film provided with a transparent conductive film is particularly preferably a protective film laminated on both surfaces of a polarizing film. Both have light transmittance of 90% or more, heat distortion temperature of 100 ° C or more, 2
Water absorption of 1.0% or less when placed in 3 ° C water for 24 hours,
The surface hardness is preferably H or higher in terms of pencil hardness. If the light transmittance is less than 90%, the transparency of the polarizing film is poor, and the image is dark when used in a display,
It will be cloudy. Further, if the heat deformation temperature is less than 100 ° C., the film is deformed by the heat applied when forming the transparent conductive film or the heat applied when the outer peripheral portion is sealed with epoxy resin after cutting the polarizing film into a predetermined size. There is. Further, if the heat deformation temperature is less than 100 ° C., the film is deformed by the heat applied when forming the transparent conductive film or the heat applied when the outer peripheral portion is sealed with epoxy resin after cutting the polarizing film into a predetermined size. There is. Further, if the water absorption rate exceeds 1.0% when placed in water at 23 ° C. for 24 hours, the moisture resistance of the protective film becomes inferior, so that the polarizing film may be deteriorated in polarization performance by being exposed to water. growing. In addition, since a film having a low surface hardness is easily scratched during device manufacturing, when used for a liquid crystal display, for example, the display performance and appearance of the display may be impaired. Therefore, it is not possible to completely prevent the scratches that occur during the manufacture of the display.
Since it is manufactured through a plurality of various processes, there is a problem in that it is extremely difficult in terms of manufacturing technology and extra cost is required. Therefore, it is preferable to use a film having a high surface hardness as the protective film in order to prevent the scratches of the polarizing film in the display production.
Specifically, the pencil hardness is H or more. A film made of a thermoplastic norbornene-based resin is preferably used as a film satisfying all the above conditions.

The thermoplastic norbornene-based resin used in the present invention has a norbornene skeleton in its repeating unit. For example, as this thermoplastic resin,
It contains a norbornene skeleton represented by the general formulas (I) to (IV).

[0010]

[Chemical 1]

[0011]

[Chemical 2]

[0012]

[Chemical 3]

[0013]

[Chemical 4]

(In the formula, A, B, C and D represent a hydrogen atom or a monovalent organic group.) The thermoplastic resin having a norbornene skeleton used in the present invention has sufficient strength. And its weight average molecular weight is 5,000 to 1,000,000, preferably 8,000 to 20.
In many cases.

Examples of the thermoplastic resin having a norbornene skeleton which can be used in the present invention include, for example, JP-A-60-168708 and JP-A-62-2524.
No. 06, No. 62-252407, No. 2-133413, No. 63-145324, No. 63-264626, and No. 1-2.
Resins described in JP-B No. 40517, JP-B No. 57-8815 and the like can be mentioned. Among these resins, a resin obtained by hydrogenating a ring-opening polymer of a norbornene-based monomer is an amorphous polymer, and therefore an optically uniform film is easily obtained, which is preferable. Specific examples of the thermoplastic resin include metathesis polymerization of at least one tetracyclododecene derivative represented by the following general formula (V) or an unsaturated cyclic compound copolymerizable with the tetracyclododecene. The hydrogenated polymer obtained by hydrogenating the obtained polymer can be mentioned.

[0016]

[Chemical 5]

(In the formula, A to D are the same as above.) In the tetracyclododecene derivative represented by the general formula (V), A, B, C and D may contain a polar group. It is preferable in terms of adhesion with other materials and heat resistance.
Further, the polar group ^{_{- (CH 2) n COOR 1}} ( wherein, R ¹ is a hydrocarbon group having 1 to 20 carbon atoms, n represents 0
It is preferable that the hydrogenated polymer obtained has a high glass transition temperature. In particular, when ^one polar substituent represented by — (CH ₂ ) _n COOR ¹ is contained per molecule of the tetracyclododecene derivative of the general formula (V), the water absorption is lowered. Is preferred. In the above general formula, R ¹
Is a hydrocarbon group having 1 to 20 carbon atoms, but is preferable in that the higher the number of carbon atoms is, the lower the hygroscopicity of the obtained hydrogenated polymer is, but the balance with the glass transition temperature of the obtained hydrogenated polymer is preferable. From the viewpoint, a chain alkyl group having 1 to 4 carbon atoms or a (poly) cyclic alkyl group having 5 or more carbon atoms is preferable, and a methyl group, an ethyl group and a cyclohexyl group are particularly preferable.

Further, tetra-carbon of the general formula (V) in which a hydrocarbon group having 1 to 10 carbon atoms is simultaneously bonded as a substituent to the carbon atom to which the group represented by-(CH ₂ ) _n COOR ¹ is bonded Cyclododecene derivatives are preferable because they lower hygroscopicity. Particularly, the tetracyclododecene derivative represented by the general formula (V) in which the substituent is a methyl group or an ethyl group is preferable in that the synthesis thereof is easy. Specifically, 8-
Methyl-8-methoxycarbonyltetracyclo [4.
4.0.1 ^2.5 1 ^7.10 ] dodeca-8-ene is preferred.
These tetracyclododecene derivatives or a mixture of unsaturated cyclic compounds copolymerizable therewith are described, for example, in JP-A-4-77520, page 4, upper right column, line 12 to page 6, lower right column, line 6; By the method described, the thermoplastic resin used in the present invention can be obtained by metathesis polymerization and hydrogenation.

In the present invention, the thermoplastic resin having a norbornene skeleton has an intrinsic viscosity (η _inh ) measured at 30 ° C. in chloroform of 0.2 to 1.5 dl / g, preferably 0.3 to 1 It is 0.0 dl / g. Intrinsic viscosity (η
_inh ) of less than 0.2 dl / g, the mechanical properties are poor,
When the impact resistance is lowered, on the other hand, when it exceeds 1.5 dl / g, the workability is poor and the film formability is poor. The hydrogenation rate of the hydrogenated polymer is 50% or higher, preferably 90% or higher, more preferably 98% or higher, as measured by ¹ H-NMR at 60 MHz. The higher the hydrogenation rate, the better the stability to heat and light. The hydrogenated polymer used as the thermoplastic resin having a norbornene skeleton of the present invention has a gel content of 5% by weight from the viewpoint of preventing the occurrence of defects such as silver streak in film molding. % Or less, preferably 1
It is particularly preferable that the content is not more than weight%.

In the present invention, the thermoplastic norbornene-based resin includes a known antioxidant such as 2,6-di-t-butyl-4-methylphenol, 2,2'-dioxy-3,
3'-di-t-butyl-5,5'-dimethyldiphenylmethane, tetrakis [methylene-3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate]
Methane, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-
Trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, stearyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate , 2,2'-dioxy-3,3 '
-Di-t-butyl-5,5'-diethylphenylmethane, 3,9-bis [1,1-dimethyl-2- (β- (3
-T-butyl-4-hydroxy-5-methylphenyl)
Propionyloxy) ethyl], 2,4,8,10-tetraoxyspiro [5.5] undecane, tris (2,4
-Di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-t-butyl) -4-Methylphenyl) phosphite, 2,2-methylenebis (4,4
6-di-t-butylphenyl) octyl phosphite;
It can be stabilized by adding an ultraviolet absorber such as 2,4-dihydroxybenzophenone or 2-hydroxy-4-methoxybenzophenone. Further, additives such as a lubricant may be added for the purpose of improving processability. The amount of these antioxidants added is usually 0.1 to 3 parts by weight, preferably 0.2 to 2 parts by weight, based on 100 parts by weight of the specific polymer. If the amount of the antioxidant used is too small, the effect of improving the durability is insufficient, and if it is too large, problems such as bleeding from the molding surface and deterioration of transparency are unfavorable.

The protective film for the polarizing film of the present invention comprises a film or sheet obtained by subjecting a thermoplastic norbornene resin to a solution casting method and a melt molding method. In the solution casting method, a film is prepared by the method described in JP-A-5-148413,
Sheets can be made. As the melt molding method, the extrusion molding method, the calender method, the hot pressing method, and the injection molding method described in JP-A-4-59218 can be used. Among the melt molding methods, the melt extrusion method is preferable. The thickness of the protective film made of a thermoplastic norbornene resin is usually 5 to 500 μm, preferably 10 to 300 μm.
m, and more preferably 20 to 200 μm. Further, the smaller the retardation of the protective film, the more preferable.

A pressure sensitive adhesive or an adhesive can be used for laminating a protective film made of a thermoplastic norbornene resin on the polarizing film of the polarizing film. As these pressure-sensitive adhesives and adhesives, those having excellent transparency are preferable, and specific examples thereof include natural rubber, synthetic rubber, vinyl acetate / vinyl chloride copolymer, polyvinyl ether, acrylic type, modified polyolefin type, and isocyanate Examples thereof include a curable pressure-sensitive adhesive containing a curing agent such as nato, an adhesive for dry lamination in which a polyurethane resin solution and a polyisocyanate resin solution are mixed, a synthetic rubber adhesive, and an epoxy adhesive. The transparent conductive polarizing film of the present invention is obtained by forming a transparent conductive film on one polarizing film protective film of the polarizing film obtained as described above.

As a material for forming the transparent conductive layer, metals such as Sn, In, Ti, Pb, Au, Pt, and Ag, or oxides thereof are generally used. When it is formed on the substrate in, it may be oxidized thereafter. There is also a method of depositing as an oxide layer from the beginning, but first, a film is formed in the form of a simple metal or a lower oxide, and after that, it is subjected to an oxidation treatment such as heating oxidation, anodic oxidation or liquid phase oxidation to make it transparent. It can also be converted. These transparent conductive films are formed into a sheet, a film, etc., and then adhered to a formed body,
It is formed on the molded body by a plasma polymerization method, a sputtering method, a vacuum deposition method, a plating method, an ion plating method, a spray method, an electrolytic deposition method or the like. The thickness of these transparent conductive films is usually 10 to 10000 angstrom, preferably 50 to 5000 angstrom, and the specific resistance of the transparent conductive film is preferably 100 ohm cm or less.

In the present invention, an anchor coat layer may be formed between the protective film and the transparent conductive film for the purpose of providing adhesion between the adhesive layer and the transparent conductive film and flattening of the film, if necessary. . As the adhesive layer, epoxy resin, polyimide, polybutadiene, phenol resin,
A heat resistant resin such as polyether ether ketone can be exemplified. As the anchor coat layer, a layer containing a so-called acrylic prepolymer such as epoxy diacrylate, urethane diacrylate or polyester diacrylate as a component is used. A known method can be used for the curing method, and for example, UV curing or heat curing is used. In the present invention, as the manufacturing order of the transparent conductive polarizing film, in addition to the method of forming a transparent conductive film on the polarizing film obtained by laminating the protective film on the polarizing film, the film used as the protective film of the polarizing film is transparent in advance. A conductive film may be formed in advance and formed on the surface of the polarizing film by using the above-mentioned bonding means.

In the present invention, the protective film on which the transparent conductive film is formed has a low water absorption rate and excellent moisture resistance, but depending on the application, deterioration due to permeation of oxygen and water vapor is further reduced, and durability is improved. For purposes such as raising, it is preferable that a gas barrier material such as polyvinylidene chloride or polyvinyl alcohol is laminated on at least one surface of the film in advance before laminating the transparent conductive layer. Further, for the purpose of improving the scratch resistance and heat resistance of the film, a hard coat layer may be laminated on the gas barrier layer. As the hard coat agent, an organic hard coat material such as an organic silicon resin, a melamine resin, an epoxy resin, an acrylic resin, or an inorganic hard coat material such as silicon dioxide can be used. Among these, hard coat materials such as organic silicon resins and acrylic resins are preferable. Among the organic silicon resins, resins having various functional groups are used, but resins having an epoxy group are preferable.

Further, the transparent conductive polarizing film of the present invention is
For example, in order to improve the workability of laminating on another film or substrate constituting a device, a pressure-sensitive adhesive layer or an adhesive layer is laminated on at least the polarizing film protective film on which the transparent conductive film is not laminated. You can also do it.
As the pressure-sensitive adhesive and the adhesive, the above-mentioned pressure-sensitive adhesive or adhesive can be used. The transparent conductive polarizing film of the present invention is used as a liquid crystal display by laminating a known retardation film, a liquid crystal alignment layer, a gas barrier film and the like. Further, the transparent conductive polarizing film of the present invention, for example, a transparent conductive film laminate in which a transparent electrode is formed on one surface of a film having a function of a retardation film and a light diffusion treatment on one surface of the film, and the other By using a combination of optical films each having a light-collecting surface, it is possible to reduce the film structure of a liquid crystal display, which has been conventionally required to be at least three, to nine. In the transparent conductive polarizing film of the present invention, the polarizing film protective film on which the transparent conductive film is not laminated may simultaneously have a retardation function. The film having such a function is obtained by forming a sheet of thermoplastic norbornene-based resin by a melt molding method and a solution casting method, and stretching orienting or pressing the sheet. As the melt molding method, a method such as a T-die method or an inflation method is used. The thickness of the sheet before stretching is usually 25 to 500 μm, preferably 50 to 400 μm, more preferably 100 to 300 μm.
m. As the stretching method, a known uniaxial stretching method, that is, a lateral uniaxial stretching method by a tenter method, a roll-to-roll compression stretching method, a longitudinal uniaxial stretching method using rolls having different circumferential distances, and the like can be used. Further, it may be biaxial stretching in which stretching is performed in a range that does not affect the orientation of the molecules, and then uniaxial stretching is performed to orient the molecules. The smaller the variation in retardation of the polarizing film protective film having a retardation function obtained as described above, the better, and it is preferably ± 20 nm or less.

Liquid crystal displays using the polarizing film of the present invention include mobile telephones, digital information terminals, pagers, in-vehicle liquid crystal displays such as navigation systems, liquid crystal monitors, light control panels, OA equipment displays, A
It can be used as a display for V equipment.

[0028]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. In the examples, parts and% are by weight unless otherwise specified. Reference Example 1 (Production of Thermoplastic Norbornene Resin) 8-Methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2.5 . 1 ^7.10 ] Dodeca-3-en 10
2. 0 g, 1,2-dimethoxyethane 60 g, cyclohexane 240 g, 1-hexene 9 g, and a solution of diethylaluminum chloride 0.96 mol / l in toluene 3.
4 ml was added to an autoclave having an internal volume of 1 liter. On the other hand, in another flask, a solution of tungsten hexachloride (0.1%) was added.
20 ml of a 05 mol / l 1,2-dimethoxyethane solution
And 10 ml of a 0.1 mol / l 1,2-dimethoxyethane solution of paraaldehyde were mixed. This mixed solution 4.9
ml was added to the mixture in the autoclave. After sealing, the mixture was heated to 80 ° C. and stirred for 2.5 hours. To the obtained polymer solution, a mixed solvent of 1/8 (weight ratio) of 1,2-dimethoxyethane and cyclohexane was added to make the polymer / solvent 1/10 (weight ratio), and then triethanolamine 20 g Was added and stirred for 10 minutes. To this polymerization solution, 500 g of methanol was added, stirred for 30 minutes and allowed to stand. The upper layer separated into two layers was removed, methanol was added again, and the mixture was stirred and allowed to stand, and then the upper layer was removed. The same operation was repeated twice, and the resulting lower layer was mixed with cyclohexane,
By appropriately diluting with 1,2-dimethoxyethane, a cyclohexane-1,2-dimethoxyethane solution having a polymer concentration of 10% was obtained. To this solution, 20 g of palladium / silica magnesia [manufactured by JGC Chemical Co., Ltd., amount of palladium = 5%] was added, and the mixture was reacted in an autoclave at a hydrogen pressure of 40 kg / cm ² at 165 ° C. for 4 hours, and then hydrogenated catalyst. Was removed by filtration to obtain a hydrogenated polymer solution. In addition, the hydrogenated polymer solution was mixed with pentaerythrityl-
Tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] was added to the hydrogenated polymer in an amount of 0.1%, and the solvent was removed at 380 ° C under reduced pressure. . Then, the molten resin was pelletized by an extruder under a nitrogen atmosphere to give an intrinsic viscosity of 0.48 dl /
g (30 ° C., in chloroform), a hydrogenation rate of 99.5%, and a thermoplastic resin A having a glass transition temperature of 168 ° C. were obtained. Reference Example 2 6-Ethylindene 2-tetracyclododecene was used as Reference Example 1.
In the same manner as above, after metathesis ring-opening polymerization, hydrogenation, pelletization and intrinsic viscosity 0.50 dl / g (30 ° C. in chloroform), weight average molecular weight 6.2 × 10 ⁴ , hydrogenation rate 99%,
A thermoplastic resin B having a glass transition temperature of 140 ° C. was obtained.

Example 1 (a) Production of Polarizing Film A polyvinyl alcohol film having a thickness of 50 μm was added with 5.0 g of iodine, 250 g of potassium iodide, 10 g of boric acid,
It was uniaxially stretched up to 4 times in about 5 minutes while being immersed in a bath of 1000 g of water at 40 ° C. The obtained film was washed with alcohol while maintaining tension and then air-dried to obtain a polarizing film.

(B) Production of Polarizing Film Protective Film Thermoplastic resin A obtained in Reference Example 1 using a melt extruder
Was melted by heating at 300 ° C. and extrusion-molded from a T-die to obtain an extruded film having a thickness of 100 μm. This film was evaluated for light transmittance, heat distortion temperature, saturated water absorption, and surface hardness.

(C) Production of transparent conductive polarizing film An acrylic resin 100 consisting of 90% by weight of n-butyl acrylate, 7% by weight of ethyl acrylate and 3% by weight of acrylic acid was formed on both sides of the polarizing film obtained in (a). Parts and a cross-linking agent consisting of 2 parts of a 75 wt% ethyl acetate solution of a trimethylolpropane (1 mol) adduct of tolylene diisocyanate (3 mol) were mixed to obtain a pressure-sensitive adhesive,
The protective film obtained in (b) was laminated to prepare a polarizing film. A transparent conductive film was formed on one surface of this film by a sputtering method using a target made of indium oxide / tin oxide (weight ratio 95: 5) to obtain a transparent conductive polarizing film. With respect to this transparent conductive polarizing film, the transparency and appearance of the film (presence or absence of scratches, warpage of the film) were visually observed. Then 80
A durability test was carried out for 1000 hours under the conditions of ° C and 90% relative humidity, and the appearance change was visually observed. Table 1 shows the above results. In addition, each measurement was performed as follows.

[0032]

[Table 1]

Light transmittance (%) A spectrophotometer was used to measure the wavelength in the range of 400 to 900 nm while continuously changing the wavelength, and the minimum transmittance was defined as the light transmittance of the film. Heat distortion temperature (° C.) Measured according to ASTM D648. Saturated Water Absorption (%) In accordance with ASTM D570, the weight gain was measured by leaving it in water at 23 ° C. for 24 hours. Surface hardness (pencil hardness) The surface hardness of the hard coat film was measured according to the pencil hardness test. Transparency of transparent conductive polarizing film ASTM D100
3 was measured. Exceeding 85% ∘ 75 to 85% ∘ Less than 75% ∘ Appearance of transparent conductive polarizing film The presence or absence of scratches and the degree of warpage of the film were evaluated according to the following evaluation criteria. ○: Good appearance with no scratches, warps or undulations △: Slight scratches, warps or undulations X: Notable for use due to significant scratches, warps or swells Humidity resistance 80 ° C The degree of polarization was measured after holding for 1000 hours under the conditions of 90% relative humidity, and the moisture resistance was evaluated according to the following evaluation criteria. ◯: The degree of polarization exceeds 90% △: The degree of polarization is 70 to 90% ×: The degree of polarization is less than 70%

Example 2 A 20 wt% toluene solution of the thermoplastic resin B obtained in Reference Example 2 was passed through a die to form a liquid having a uniform thickness.
It was dried at 00 ° C. to obtain a cast film having a thickness of 100 μm. A transparent conductive polarizing film was prepared and evaluated in the same manner as in Example 1 except that this film was used as a polarizing film protective film.

Comparative Example 1 A transparent conductive polarizing film was prepared in the same manner as in Example 1 except that a triacetyl cellulose film (manufactured by Fuji Photo Film Co., Ltd., thickness: 0.1 mm) was used as the polarizing film protective film. An evaluation was made.

Comparative Example 2 A transparent conductive polarizing film was prepared and evaluated in the same manner as in Example 1 except that a polymethylmethacrylate film (manufactured by Mitsubishi Rayon Co., Ltd., thickness: 0.1 mm) was used as the polarizing film protective film. I went.

Comparative Example 3 A transparent conductive polarizing film was prepared and evaluated in the same manner as in Example 1 except that a polyethylene terephthalate film (manufactured by Toray Industries, Inc., thickness: 0.1 mm) was used as the polarizing film protective film. .

Comparative Example 4 A transparent conductive polarizing film was prepared and evaluated in the same manner as in Example 1 except that a polycarbonate film (manufactured by Teijin Ltd., thickness: 0.1 mm) was used as the polarizing film protective film.

Table 1 shows the evaluation results of the above Examples and Comparative Examples. As is clear from Table 1, the transparent conductive polarizing film of the present invention (Examples 1 and 2) has an excellent appearance without scratches, warps or undulations in the assembly process, and also has excellent transparency. It is a thing. In addition, the performance is not deteriorated even when left for a long time under the condition of high temperature and high humidity, and the reliability is high. On the other hand, Comparative Example 1 uses a TAC film as the polarizing film protective film, and is inferior in durability under high temperature and high humidity. In addition, Comparative Example 2 uses a polymethylmethacrylate film and has a heat distortion temperature of less than 100 ° C. and a water absorption rate of more than 1.0%, and therefore has durability in high temperature and high humidity. Inferior. In addition, Comparative Example 3
Uses a polyethylene terephthalate film, has a light transmittance of less than 90%, and is extremely inferior in transparency when used as a transparent conductive polarizing film. Also,
Comparative Example 4 uses a polycarbonate film, has a small surface hardness, and has many scratches on the film in the assembly process.

[0040]

Since the transparent conductive polarizing film of the present invention uses a polarizing film protective film having specific physical properties, the film is not deformed even when a transparent conductive film is formed, and has durability under high temperature and high humidity. , And excellent transparency, and by using the film, it is possible to make the liquid crystal display thinner and lighter.

Claims (2)

[Claims] 1. A protective film is laminated on both sides of a polarizing film,
Further, in the transparent conductive polarizing film having a transparent conductive film provided on one of the protective films, at least the protective film provided with the transparent conductive film has a light transmittance of 90% or more, a heat distortion temperature of 100 ° C. or more, and 23 ° C. in water. A transparent conductive polarizing film comprising a film having a water absorption rate of 1.0% or less when left standing for 24 hours and a surface hardness of H or more in terms of pencil hardness. 2. The transparent conductive polarizing film according to claim 1, wherein the protective film provided with at least the transparent conductive film is made of a thermoplastic norbornene resin. [0001]