JPH0895016A - Transparent conductive film and its laminate - Google Patents

Abstract

PURPOSE: To reduce the number of films constituting a liquid crystal display and provide the thinner, lighter, well-productive, more reliable and more bright liquid crystal display by forming a transparent electrode on one face of the film with the function of a phase different film. CONSTITUTION: A transparent electrode 2 is formed on one face of a film 1 with the function of a phase different film. The film 1 with the function of the phase different film formed of thermoplastic norbolnen based resin has a retardation of 20-200nm. A transparent conductive film laminate has protective films 1, 4 laminated on both sides of a polarizing membrane 3 and a transparent conductive membrane 2 granted to one protective film 1, at least the protective film 1 to which the transparent conductive membrane 2 having the function of a phase different film at this time. At least the protective film 1, to which the transparent conductive membrane 2 is granted, formed of thermoplastic norbolnen based resin has a retardation of 20-200nm.

Description

Detailed Description of the Invention

INDUSTRIAL APPLICABILITY The present invention improves the productivity of a liquid crystal display by reducing the number of films constituting the liquid crystal display because the retardation film also functions as a transparent conductive film. In addition, the present invention relates to a transparent conductive polarizing film that can 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. Conventionally, a retardation film is used for a liquid crystal display in a form in which a polarizing film or a transparent conductive film is laminated with an adhesive layer as shown in FIG. 3, but the conventional polarizing film is a polyvinyl alcohol film. A protective film made of triacetyl cellulose (TAC) is laminated on both sides of the polarizing film to which iodine or dye is attached to maintain the durability and mechanical properties of the polarizing film. Is usually polyether sulfone (PES) or polyarylate (PAR)
A transparent conductive film is laminated on a transparent film substrate such as. Since there are many types of films and sheets, the assembly process is complicated and there are restrictions on cost reduction. Also, as the number of laminated layers increases, the light transmittance decreases and the image becomes darker. Was strong.

Further, there are many problems in the film itself which has been widely used as a film having various functions constituting a liquid crystal display. For example, retardation films are required to have uniform birefringence over the entire surface and to have no change in optical characteristics even under severe conditions of high temperature and high humidity in order to obtain clear colors and fine images. . On the other hand, as liquid crystal displays have been colorized by the TFT method, it has been strongly required that birefringence that is not too large be uniform over the entire surface. As the retardation film, a film obtained by stretching and orienting a film made of carbonate (PC) is usually used, but since the photoelastic coefficient is as large as 9 × 10 ^-12 cm ² / dyne, the birefringence becomes large. Too much, non-uniform birefringence,
There is a problem that the birefringence changes due to a slight stress generated at the time of assembly or due to environmental changes. In addition, since the surface hardness of the PC film is small, there is a problem during film production and device assembly. Furthermore, the transparent film base material of the transparent conductive film is required to have excellent heat resistance, surface smoothness, optical characteristics, and moisture resistance, and PES and PAR, which have superior heat resistance to conventional ones, have been used. A film made of PES is inferior in transparency, and PAR is likely to have optical distortion, and a complicated technique was required to obtain a transparent and optically uniform film. Furthermore, the protective film has a low birefringence,
Performances such as heat resistance, moisture absorption resistance, high mechanical strength, surface smoothness, and adhesion to adhesives and adhesives are required, and generally casting method with excellent low birefringence and surface smoothness. The TAC film manufactured in
C film is not always satisfactory in durability under high temperature and high humidity, heat resistance, and adhesion, and problems have come to be strongly pointed out as liquid crystal displays have been adopted as in-vehicle displays. As described above, the polarizing film used in a liquid crystal display has not only problems due to the characteristics of the material itself used, but also the thin film and light weight of the liquid crystal display because each film has the required function. It was difficult to reduce the number of films in spite of strong demand for conversion.

[0004]

The present invention improves the optical characteristics of PES and PAR used as a transparent conductive film substrate, and improves the optical non-uniformity of a PC film used as a retardation film, And by integrating the retardation film and the transparent conductive film function, the steps such as adhesion are omitted, the decrease in reliability due to adhesion is eliminated, and the liquid crystal display is made thinner by reducing the number of films used, (EN) Provided is a transparent conductive film which achieves the improvement in brightness of a liquid crystal display at once by reducing the weight and improving the light transmittance of a laminated film.

[0005]

DISCLOSURE OF THE INVENTION The present invention is characterized in that a transparent electrode is formed on one surface of a film having a function of a retardation film, and a transparent conductive film and protective films are laminated on both sides of a polarizing film. In the transparent conductive film laminate in which a transparent conductive film is further provided on one of the protective films, at least the protective film provided with the transparent conductive film has the function of a retardation film at the same time. It is provided. In the present invention, the film having the function of a retardation film refers to a film that may be used as another functional film such as a polarizing film protective film in addition to being used as a retardation film.

The present invention will be described in detail below. FIG. 1 is a schematic sectional view of the transparent conductive film of the present invention. First
In the figure, reference numeral 1 is a film having a function of a retardation film, and a transparent electrode is laminated on the film 1. In FIG. 2, a film 1 having a function of a retardation film is formed on one surface of a polarizing film 3, a polarizing film protective film 4 is laminated on the other surface, and a transparent conductive film 2 is further laminated on the surface of one. Here is an example. In FIG. 2, reference numeral 1 also has a function of a polarizing film protective film. In FIGS. 1 and 2, a film having a function as a retardation film is preferably one having a property required as a retardation film, that is, a film having optically uniform birefringence obtained by stretch orientation, such as vinylon or polyvinyl. Alcohol, polycarbonate, polystyrene iron, butyl cellulose acetate, cellophane,
A polyether sulfone resin, a polysulfone resin or a polyarylate resin, a thermoplastic nornornene resin, or the like can be used. Further, in FIG. 2, the protective film laminated on the polarizing film has a thickness of about 5
A transparent film having an optical uniformity of 500 μm and a small retardation can be used.

Specifically, cellulose-based films such as diacetyl cellulose and triacetyl cellulose, polyester-based films such as polyethylene terephthalate, polyethylene isophthalate and polybutylene terephthalate, acrylics such as poly (meth) acrylate and polyethyl (meth) acrylate. A resin film, a polycarbonate film, a polyether sulfone film, a polysulfone film, a polyimide film, a thermoplastic norbornene resin film, or the like can be used. The film having the functions of the protective film and the retardation film can be selected freely according to the required characteristics and cost required for each application, and the film type as a material can be freely selected. It is preferable that the film having at least the function of a retardation film is a film made of a thermoplastic norbornene-based resin in terms of improving the transparency of the body, and it is protected when higher optical properties, heat resistance and moisture resistance are required. Both the film and the film having the function of a retardation film are preferably films made of a thermoplastic norbornene-based resin.

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

[0009]

[Chemical 1]

[0010]

[Chemical 2]

[0011]

[Chemical 3]

[0012]

[Chemical 4]

(In the formula, A, B, C and D represent a hydrogen atom or a monovalent organic group.) The thermoplastic resin having a norbornane skeleton used in the present invention is required to have 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 norbornane 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.

Generally, a thermoplastic norbornene-based resin is a resin having excellent optical properties, heat resistance and moisture resistance, but when the polarizing film for a liquid crystal display of the present invention is used in a harsh environment such as a vehicle, it may be used for a long time. It is preferable to specify the glass U transition temperature (Tg) and the saturated water absorption of the resin in order to prevent the deterioration of the optical properties due to use.
It is preferable that g is 120 ° C. or higher and the saturated water absorption is 1.0% or lower. In the present invention, general formulas (I) to (I
The Tg and the saturated water absorption of the thermoplastic norbornene-based resin having the norbornane skeleton of the structure represented by V) can be controlled by the kinds of the substituents A, B, C and D and the kind of R ¹ in the case of an ester group. . 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 norbornane 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 norbornane 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 streaks 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.

In the present invention, the film having the function of a retardation film is obtained by forming a sheet of a thermoplastic norbornene resin by a solution casting method and a melt molding method, and stretching orienting or surface pressing the sheet. As the solution 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 μ.
m, preferably 50 to 400 μm, more preferably 1
It is from 00 to 300 μm. As a 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, and a longitudinal uniaxial stretching method using rolls having different circumferential distances 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 film obtained as described above is partially oriented by stretching and has a constant retardation value, but the retardation is the retardation and stretching ratio of the sheet before stretching, the stretching temperature, the thickness of the stretched and oriented film. It can be controlled by When the sheet before stretching has a constant thickness, the absolute value of the retardation tends to increase as the stretching ratio of the film increases, so that a stretched oriented film having a desired retardation can be obtained by changing the stretching ratio. it can.

In the present invention, the film obtained by the above-mentioned method has a retardation measured by a deflection microscope of 5 to 900 nm. The preferred retardation range varies depending on the type and shape of the liquid crystal display. A polarizing film used for a liquid crystal display by the TFT method needs to have particularly high transparency, and an optically uniform film having a small retardation of 10 to 80 nm is preferably used.

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 adhesive layer and an anchor coat layer may be formed between the film having the function of a retardation film and the transparent conductive film, if necessary. Examples of the adhesive layer include heat resistant resins such as epoxy resin, polyimide, polybutadiene, phenol resin, and polyether ether ketone. 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. As a curing method, a known method can be used,
For example, UV curing or heat curing is used. The transparent conductive film of the present invention can be combined with a polarizing film to form a laminate. Here, the method for combining the transparent conductive film and the polarizing film is not particularly limited, and a modified film in which protective films are laminated on both surfaces of the polarizing film is provided on the side opposite to the transparent conductive film forming surface of the transparent conductive film of the present invention. It may be laminated on the above with a suitable pressure-sensitive adhesive, but if necessary, a suitable pressure-sensitive adhesive or adhesive layer may be formed on the side opposite to the transparent conductive film forming surface of the transparent conductive film as shown in FIG. It is preferable that the polarizing film is laminated through the protective film and that the protective film is laminated on the polarizing film because the number of films can be reduced and the decrease in transparency due to film lamination can be minimized. . In the present invention, the polarizing film used in the transparent conductive protective film laminate is not particularly limited as long as it has a function as a polarizer. For example, PVA / iodine type polarizing film, PVA
A dye-based polarizing film in which a dichroic dye is adsorbed and oriented on a base film, or a polyene-based polarizing film in which a polyene is formed by inducing a dehydration reaction from a PVA-based film or a dehydrochlorination reaction of a polyvinyl chloride film, Examples thereof include a polarizing film having a dichroic dye on the surface and / or inside of a PVA-based film made of modified PVA having a cationic group in the molecule. The manufacturing method of the polarizing film is 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 of producing a polarizing film by immersing at ~ 40 ° C, or a PVA film is similarly treated with boric acid and stretched uniaxially about 3 to 7 times to form a dichroic dye aqueous solution of 0.05 to 5% by weight. There is a method in which a dye is adsorbed by dipping at a bath temperature of 30 to 40 ° C., dried at 80 to 100 ° C. and heat-fixed to produce a polarizing film.

In the transparent conductive film laminate of the present invention, when a thermoplastic norbornene-based resin is used as a protective film laminated on a polarizing film and having no retardation function, a solution rolling method or a melt molding method is known. A film can be obtained by using the above method. In the solution casting method, a film or sheet can be produced by the method described in JP-A-5-148413. In the melt molding method, Japanese Patent Laid-Open No.
Although it can be produced by the extrusion molding method, calendering method, heat pressing method, or injection molding method described in Japanese Patent No. 59218,
Among the melt molding methods, the melt extrusion method is preferable. The thickness of the protective film made of a thermoplastic norbornene-based resin is usually 5 to 500 μm, preferably 10 to 300 μm, and more preferably 20 to 200 μm. In the present invention, as the production order of the transparent conductive film laminate, in addition to the method of forming a transparent conductive film on a polarizing film obtained by laminating a film having a function of a protective film and a retardation film on a polarizing film, a polarizing film. A transparent conductive film may be formed in advance on a film having a function of a retardation film used as the protective film, and then the transparent conductive film may be formed on the surface of the polarizing film using the above-mentioned bonding means. In the present invention, the film having the function of the retardation film used as the transparent film substrate of the transparent conductive film is, if necessary, further reduced in the deterioration due to the permeation of oxygen and water vapor, for the purpose of increasing the durability, etc. For this reason, a gas barrier material such as polyvinylidene chloride or polyvinyl alcohol can be preliminarily laminated on at least one surface of the film 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, the film having at least the function of a retardation film as a base material, the surface opposite to the surface of the transparent conductive film, or the transparent film of the present invention. A pressure-sensitive adhesive layer or an adhesive layer may be laminated on the polarizing film protective film of the conductive film laminate. As adhesives and adhesives,
The above-mentioned pressure-sensitive adhesive or adhesive can be used. The transparent conductive film and the laminate thereof of the present invention,
A known liquid crystal alignment layer, a gas barrier film, etc. are laminated and used as a liquid crystal display.

Liquid crystal displays using the transparent conductive film and the laminate thereof of the present invention include mobile phones, digital information terminals, pagers, in-vehicle liquid crystal displays for navigation, liquid crystal monitors, light control panels, OA equipment displays, It can be used as a display for AV 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 (Production of Protective Film by Casting Method) A 20 wt% toluene solution of the thermoplastic resin A obtained in Reference Example 1 was passed through a die to form a layer having a uniform thickness.
It was dried at 00 ° C. to obtain a cast film having a thickness of 100 μm. Reference Example 3 (Production of Protective Film by Extrusion Method) The thermoplastic resin A obtained in Reference Example 1 was heated and melted to 300 ° C. by using a melt extruder, and extrusion-molded from a T-die to obtain a film having a thickness of 100 μm. An extruded film was obtained. Reference Example 4 (Film having a function as a retardation film) a) Production from cast film Using the thermoplastic resin A obtained in Reference Example 1, the width of the die is changed so that the film thickness after drying exceeds 100 μm. A cast film was obtained by the same method as in Reference Example 2 except that This film and the film thickness after stretching are 1
At a draw ratio set to be 00 μm, a temperature of 17
A stretched film having a thickness of 100 ± 2 μm was obtained which was uniaxially stretched at 0 ° C. b) Production from Extruded Film The thermoplastic resin A obtained in Reference Example 1 was extrusion molded in the same manner as in Reference Example 3 to obtain an extruded film having a thickness of more than 100 μm. This film has a film thickness of 1 after stretching.
At a draw ratio set to be 00 μm, a temperature of 17
The film was stretched uniaxially at 0 ° C. to obtain a stretched film having a thickness of 100 ± 2 μm.

Reference Example 5 (Production of Polarizing Film) A polyvinyl alcohol film having a thickness of 50 μm was used, 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. Examples 1 and 2 As shown in Table 1, the film thickness, the light transmittance, the retardation value, and the variation thereof of the film A on which the transparent conductive film was laminated were measured. A transparent conductive film was formed on one surface of this film A by a sputtering method using a target made of indium oxide / tin oxide (weight ratio 95: 5) to obtain a transparent conductive film. With respect to this transparent conductive film, the transparency and appearance of the film (presence or absence of scratches, warpage of the film) were evaluated. Table 1 shows the above measurement results. In addition, each measurement was performed as follows.

Film thickness (μm) It was measured by a dial type thickness gauge. Light transmittance (%) It was measured by a spectrophotometer while continuously changing the wavelength in the wavelength range of 400 to 900 nm, and the minimum transmittance was defined as the light transmittance of the film. Retardation value (nm) Measured with an ellipsometer. Transparency of transparent conductive film The light transmittance of the transparent conductive polarizing film is ASTM D100.
3 was measured. Exceeding 85% ・ ・ ・ ○ 75 to 85% ・ ・ ・ △ Less than 75% ・ ・ ・ × Appearance of transparent conductive 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: Marked scratches, warps or undulations that cannot be used

Comparative Example 1 (Conventional Example) A film was formed in the same manner as in Reference Example 4- (a) except that polycarbonate (Panlite, manufactured by Teijin Chemicals Ltd.) was used. Film thickness, light transmittance, and retardation value were measured. This film has a thickness of 100 μm as film A.
Of polyarylate film 7U (Ermec, manufactured by Kanegafuchi Chemical Industry Co., Ltd.) of acrylic resin consisting of 90% by weight of n-butyl acrylate, 7% by weight of ethyl acrylate and 3% by weight of acrylic acid and tolylene diisocyanate (3 mol). ) Adhesion using a pressure-sensitive adhesive (adhesive A) obtained by mixing a cross-linking agent consisting of 2 parts of a 75 wt% ethyl acetate solution of trimethylolpropane (1 mol) addition monomer in (1) to obtain a film laminate. It was The variation in retardation of this film laminate was measured. A transparent conductive film was formed on the side surface of the transparent film substrate of this film laminate in the same manner as in Examples 1 and 2 to prepare a transparent conductive film with a retardation film. This film was evaluated for transparency and appearance in the same manner as in Example 1. The results are shown in Table 1.

[0032]

[Table 1]

Examples 3 to 5 Films A and D shown in Table 2 were laminated on the polarizing film obtained in Reference Example 5, and then a transparent conductive film was laminated on film A in the same manner as in Example 1. , Glued. The obtained film was evaluated for transparency, appearance and moisture resistance. The results are shown in Table 2. The humidity resistance was measured by the following method. Moisture resistance The degree of polarization was measured after holding for 1000 hours under the conditions of 80 ° C and 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%

Comparative Example 2 A polarizing film, a retardation film and a transparent conductive film shown below were laminated in the order shown in Table 2 using the above-mentioned adhesive A to prepare a film laminate. The obtained film was evaluated for transparency, appearance and moisture resistance. The results are shown in Table 2. Polarizing film: Triacetyl cellulose was laminated as a protective film on both surfaces of the polarizing film obtained in Reference Example 5 with an adhesive A interposed therebetween. A retardation film-polycarbonate (Panlite, manufactured by Teijin Chemicals Ltd.) was molded in the same manner as in Reference Example 4- (a). In the same manner as in Example 1, a transparent conductive film was formed on one of the transparent conductive film and polyarylate film (Ermec, manufactured by Kaneka Corporation).

[0037]

[Table 2]

[0038]

The transparent conductive film and the laminate thereof of the present invention are composed of a transparent conductive film substrate of a transparent conductive film, a retardation film, and a polarizing film protective film, which are integrated. The number of displays can be reduced, which can greatly contribute to thinning, weight reduction, productivity, reliability, and improvement in brightness of liquid crystal displays. Further, in the present invention, when using a film made of a thermoplastic norbornene-based resin for the film having the function of the retardation film, it is particularly excellent in transparency,
A polarizing film that is optically uniform and has excellent heat resistance and moisture resistance can be obtained.

[0039]

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of a transparent conductive film of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of a transparent conductive film laminate of the present invention.

FIG. 3 is a schematic cross-sectional view showing an example of a laminated body in which a conventional polarizing film, retardation film, and transparent conductive film are laminated with an adhesive layer interposed therebetween.

[Explanation of symbols]

 1 film having a function of a retardation film 2 transparent conductive film 3 polarizing film 4 protective film 5 transparent conductive film 6 transparent film substrate 7a and 7b adhesive layer

Claims (4)

[Claims] 1. A transparent conductive film having a transparent electrode formed on one surface of a film having a function of a retardation film. 2. A film having a function of a retardation film is made of a thermoplastic norbornene resin and has a retardation of 20 to 200 nm.
Transparent conductive film described 3. A protective film is laminated on both sides of the polarizing film,
A transparent conductive film laminate in which a transparent conductive film is provided on one protective film, wherein at least the protective film provided with the transparent conductive film simultaneously has the function of a retardation film. 4. The film laminate according to claim 3, wherein the protective film provided with at least the transparent conductive film is made of a thermoplastic norbornene resin and has a retardation of 20 to 200 nm. [0001]