JP2009170251A - Transparent conductive film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent conductive film having excellent dimensional stability even with change of humidity. <P>SOLUTION: Aromatic polyester containing an acid constituent represented by formula (1) and a diol constituent represented by formula (2) is used as a material for a substrate. In the formula (1), R<SP>A</SP>is an alkylene group with the carbon number of 2C to 10C, and, in the formula (2), R<SP>C</SP>is an alkylene group with the carbon number of 2C to 10C. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a transparent conductive film. More specifically, the present invention relates to a transparent conductive film excellent in dimensional stability which gives a flat panel display or electronic paper excellent in reliability even when left in a high humidity environment for a long time.

  In recent years, in the field of flat panel displays such as liquid crystal display elements and organic EL display elements, a study to replace a plastic film made of a transparent polymer with a conventional glass substrate in order to improve breakage resistance, reduce the weight, and reduce the thickness. Has been continued. However, the plastic has a problem that the dimensional change due to heat and moisture absorption is larger than that of glass, and gas and water vapor are easily transmitted.

  For example, in recent years, in order to improve the display quality of a liquid crystal display, high definition, high capacity, and multi-tone color display have been studied. For the former, the use of a high-temperature firing orientation film for obtaining a high pretilt angle and a high-temperature pressure-bonding anisotropic conductive film that provides fine pitch and good connection reliability has been studied. Fine processing of pixel electrodes and color filters has become one of the elemental technologies. Therefore, the plastic film used as the base material is required to have further heat resistance and dimensional stability that can withstand these processes.

  On the other hand, Patent Document 1 describes a transparent conductive film for a display in which an indium oxide film is formed on a polyethersulfone film having a small birefringence. However, although the transparent conductive film described in Patent Document 1 is excellent in heat resistance, it is a film having a large heat shrinkage rate and a significant dimensional change due to water absorption. Therefore, many defects such as die lines, gelled products, and fish eyes occurred on the film surface. Therefore, depending on the film described in Patent Document 1, it has been difficult to realize a display having excellent display quality.

  Further, Patent Document 2 discloses a display substrate comprising a 1,1-bis (4-hydroxyphenyl) -alkylcycloalkane having a phase difference adjusted in the range of 10 to 2000 nm and a polycarbonate or polyester carbonate comprising a substitution product thereof. It is described to be used. However, although the film described in Patent Document 2 is excellent in heat resistance, it has a large amount of dimensional change after high-temperature heating and has poor water vapor barrier properties. Therefore, it is difficult to obtain a display excellent in display quality with the film. Met.

JP 59-158015 A JP 07-246661 A

  This invention is made | formed in view of this present condition, and it aims at providing the transparent conductive film which has the outstanding dimensional stability also by a humidity change.

  The present inventors diligently studied to solve the above problems. As a result, it has been found that by using an aromatic polyester having a repeating unit having a specific structure as a material for a substrate, a transparent conductive film having excellent moisture resistance environment characteristics can be obtained, and the present invention has been completed.

  That is, the present invention provides at least one surface of a polymer film mainly composed of an aromatic polyester containing an acid component represented by the following formula (1) and a diol component represented by the following formula (2): It is a transparent conductive film in which a transparent conductive layer is formed.

（式中、Ｒ^Ａは、炭素数２〜１０のアルキレン基である。）

（式中、Ｒ^Ｃは、炭素数２〜１０のアルキレン基である。）

(In the formula, ^RA is an alkylene group having 2 to 10 carbon atoms.)

(In the formula, R ^C is an alkylene group having 2 to 10 carbon atoms.)

  According to the present invention, by using an aromatic polyester having a repeating unit having a specific structure as a base material, it is possible to provide a transparent conductive film having very little dimensional change with respect to humidity change. Such a transparent conductive film is particularly useful for flat panel displays excellent in liquid crystal, organic EL, and other display quality such as high definition, high capacity, multi-tone, and color display.

  Furthermore, the aromatic polyester which contains the repeating unit of said Formula (1) 50 mol% or more and 100 mol% or less, and contains the repeating unit represented by following formula (3) 0 mol% or more and 50 mol% or less. If used, in addition to dimensional stability against humidity changes, gas barrier properties and heat resistance can be provided.

（式中、Ｒ^Ｂはフェニレン基またはナフタレンジイル基である。）

(In the formula, R ^B is a phenylene group or a naphthalenediyl group.)

  Alternatively, the aromatic further contains 5 mol% or more and less than 50 mol% of the repeating unit of the formula (1), and contains 50 mol% or more and 95 mol% or less of the repeating unit represented by the formula (3). If polyester is used, in addition to dimensional stability against humidity changes, dimensional stability against temperature changes and processability can be provided.

Hereinafter, the present invention will be described in detail.
<Aromatic polyester>
The aromatic polyester constituting the polymer film of the present invention contains an acid component and a diol component.

[Acid component]
As an acid component, the repeating unit represented by following formula (1) is included.

In the formula, R ^A is an alkylene group having 2 to 10 carbon atoms. Examples of the alkylene group that becomes ^RA include an ethylene group, a propylene group, an isopropylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, and an octamethylene group.

  By using, as a polymer film, an aromatic polyester containing a component that becomes a repeating unit represented by the above formula (1) as an acid component, and a component that becomes a repeating unit represented by the following formula (2) as a diol component: The transparent conductive film of the present invention is a film having excellent dimensional stability against changes in humidity.

In the present invention, the repeating unit represented by the above formula (1) is 6,6 ′-(ethylenedioxy) di-2-naphthoic acid, 6,6 ′-(trimethylenedioxy) di- It is preferably a unit derived from at least one selected from the group consisting of 2-naphthoic acid and 6,6 ′-(butylenedioxy) di-2-naphthoic acid. Among these, even-numbered carbon atoms of R ^A in formula (1) are preferable, and it is a repeating unit derived from 6,6 ′-(ethylenedioxy) di-2-naphthoic acid, which is resistant to changes in humidity. This is particularly preferable from the viewpoint of dimensional stability.

Moreover, in this invention, the aromatic unit which contains the repeating unit of the said Formula (1) 50 mol% or more and 100 mol% or less, and contains the repeating unit represented by following formula (3) 0 mol% or more and 50 mol% or less. If group polyester is used, in addition to the dimensional stability with respect to a humidity change, gas barrier property and heat resistance can be provided.
In this case, the content of the repeating unit represented by the above formula (1) is preferably 70 to 100 mol%, more preferably 80 to 100 mol%.

In the formula, R ^B is a phenylene group or a naphthalenediyl group. Examples of the repeating unit represented by the formula (3) include units derived from terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and combinations thereof. .

  Alternatively, the repeating unit having a specific structure of the above formula (1) is contained in an amount of 5 mol% or more and less than 50 mol%, and the repeating unit represented by the formula (3) is more than 50 mol% and not more than 95 mol%. If the aromatic polyester containing is used, in addition to the dimensional stability with respect to a humidity change, the dimensional stability with respect to a temperature change and processability can be provided.

  In this case, the upper limit of the content of the repeating unit represented by the above formula (1) is preferably 45 mol%, more preferably 40 mol%, still more preferably 35 mol%, and particularly preferably 30 mol%. The lower limit is preferably 5 mol%, more preferably 7 mol%, still more preferably 10 mol%, and particularly preferably 15 mol%. Therefore, the content of the repeating unit represented by the above formula (1) is preferably 5 to 45 mol%, more preferably 7 to 40 mol%, still more preferably 10 to 35 mol%, and particularly preferably 15 to 30 mol%. Mol%.

Moreover, as an acid component which comprises the aromatic polyester used for this invention, other acid components can also be used together other than the acid component shown to the said Formula (1) and (3). Other acid components are represented, for example, by the following formula (6) or (7).
HOOC-R ¹ -COOH (6)
^HOOC-R 2 -OH (7)
R ¹ and R ² are not particularly limited, and examples thereof include hydrocarbon groups having 2 to 10 carbon atoms. In this hydrocarbon group, a lower alkyl group, halogen or the like may be substituted with a nucleus.

  Specific examples of other acid components not represented by the above formulas (1) and (3) include 1,4-phenylenedioxydicarboxylic acid, 1,3-phenylenedioxydiacetic acid, 4,4 Aromatic dicarboxylic such as' -diphenyldicarboxylic acid, 4,4'-diphenylether dicarboxylic acid, 4,4'-diphenylketone dicarboxylic acid, 4,4'-diphenoxyethanedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid Acids, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid, or succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecadicarboxylic acid, dodecadicarboxylic acid And aliphatic dicarboxylic acids such as

  These other acid components not represented by the above formulas (1) and (3) may be used alone or in combination of two or more. Such other acid components are preferably less than 50 mol%, more preferably less than 30 mol%, based on the total acid components.

[Diol component]
As a diol component, the component represented by following formula (2) is included.

In the formula, R ^C is an alkylene group having 2 to 10 carbon atoms. Examples of the alkylene group that becomes R ^C include an ethylene group, a propylene group, an isopropylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, and an octamethylene group.

  In particular, glycols having an even number of carbon atoms such as ethylene glycol are preferable because the mechanical properties and heat resistance of the obtained polyester can be improved. Examples of the glycol having an even number of carbon atoms include ethylene glycol, isopropylene glycol, tetramethylene glycol, hexamethylene glycol, and octamethylene glycol. Of these, ethylene glycol and tetramethylene glycol are preferable, and ethylene glycol is particularly preferable.

  The content of the diol component represented by the above formula (2) in the present invention is preferably 90 mol% or more, more preferably 90 to 100 mol%, still more preferably 95 to 100 mol%, based on the entire diol component. Most preferably, it is 98-100 mol%.

  As a diol component, you may contain the repeating unit represented by following formula (5) in the range of 0-10 mol% other than the component represented by the said Formula (2). Content of the diol component represented by following formula (5) becomes like this. Preferably it is 0-5 mol%, More preferably, it is 0-2 mol%.

In formula, ^RD is a C2-C10 alkylene group. Examples of the alkylene group that becomes ^RD include an ethylene group, a propylene group, an isopropylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, and an octamethylene group. Moreover, ^RD may be not only one type but also two or more types.

  The aromatic polyester used in the present invention comprises an ester of the above acid component and glycol component, but contains 6,6 ′-(ethylenedioxy) di-2-naphthoic acid component and ethylene glycol. Is preferably 2 to 10 and the ester unit with the glycol component having an even number of carbon atoms forming the main chain is 50% or more, further 70% or more, particularly 80% or more of all repeating units. .

[Other ingredients]
The aromatic polyester used in the present invention may contain other copolymer components in addition to the acid component and the glycol component as long as the object and effect of the present invention are not impaired. Other copolymer components include, for example, hydroxycarboxylic acids such as glycolic acid, p-hydroxybenzoic acid, p-β-hydroxyethoxybenzoic acid, alkoxycarboxylic acids, stearyl alcohol, benzyl alcohol, stearic acid, behenic acid, Monofunctional components such as benzoic acid, t-butylbenzoic acid, benzoylbenzoic acid, tricarballylic acid, trimellitic acid, trimesic acid, pyromellitic acid, naphthalenetetracarboxylic acid, gallic acid, trimethylolethane, trimethylolpropane, glycerol , Trifunctional or higher polyfunctional components such as pentaerythritol and sugar ester.

  The aromatic polyester used in the present invention includes other types of thermoplastic polymers, stabilizers such as UV absorbers, antioxidants, plasticizers, lubricants, flame retardants, release agents, pigments, nucleating agents, and fillers. An agent, glass fiber, carbon fiber, layered silicate, or the like may be blended as necessary.

  Other types of thermoplastic polymers include polyester resins, polyamide resins, polycarbonates, ABS resins, polymethyl methacrylates, polyamide elastomers, polyester elastomers having a different composition from the above-mentioned aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate. Etc.

<Physical properties of aromatic polyamide>
[Intrinsic viscosity]
The aromatic polyester used in the present invention preferably has an intrinsic viscosity measured at 35 ° C. using a mixed solvent of P-chlorophenol / 1,1,2,2-tetrachloroethane (mass ratio 40/60), preferably 0. 0.4 to 3.0 dl / g, more preferably 0.5 to 2.8 dl / g, and particularly preferably 0.6 to 2.5 dl / g.

[Melting point]
The melting point of the aromatic polyester used in the present invention is preferably in the range of 200 to 260 ° C, more preferably in the range of 205 to 255 ° C, and particularly preferably in the range of 210 to 250 ° C. The melting point can be measured by DSC.
When the melting point exceeds 260 ° C., when the film is formed by melt extrusion, the fluidity is inferior, and the discharge is likely to be non-uniform. On the other hand, when the melting point is less than 200 ° C., although the film forming property is excellent, physical properties such as mechanical properties of the polyester are easily impaired.

  In general, a copolymer has a lower melting point than a homopolymer and tends to decrease mechanical strength. However, even if the aromatic polyester used in the present invention is a copolyester containing a repeating unit of the general formula (1) and a repeating unit of the general formula (3), it has a single unit having the repeating unit of the formula (1). Compared to a polymer, it has an excellent characteristic that its melting point is low but its mechanical strength is comparable. The melting point can be adjusted by controlling the type and amount of copolymerization component and the by-product dialkylene glycol.

[Glass transition point]
The glass transition temperature (hereinafter sometimes referred to as Tg) of the aromatic polyester used in the present invention is preferably 80 to 120 ° C, more preferably 82 to 118 ° C, and still more preferably 85 to 118 ° C. is there. The glass transition temperature can be measured by DSC.
When Tg is in this range, a film excellent in heat resistance and dimensional stability can be obtained. The glass transition temperature can be adjusted by controlling the type and amount of copolymerization component and the by-product dialkylene glycol.

[Content of dialkylene glycol component]
In the aromatic polyester used in the present invention, the dialkylene glycol component as a reaction byproduct is preferably less than 10 mol%, and more preferably 7 mol% or less. If the dialkylene glycol remains in the polymer or the component is contained in the polymer skeleton, the rigidity of the main chain is lost, which causes a decrease in mechanical properties and heat resistance. It is known that such a dialkylene glycol component is produced by a reaction between glycol components or a reaction between hydroxy ends of polymer ends. When the glycol component is ethylene glycol, diethylene glycol is produced. The content of dialkylene glycol can be measured by a nuclear magnetic resonance apparatus.

[Terminal carboxy concentration]
The aromatic polyester used in the present invention preferably has a terminal carboxy concentration of 200 eq / ton or less, more preferably 0.1 to 150 eq / ton, and still more preferably 0.1 to 100 eq / ton.
Polyester usually has a small equilibrium constant for the polycondensation reaction, so an increase in the amount of carboxy ends causes an increase in water absorption and acid catalysis by the carboxy group, resulting in an increase in hydrolyzability, and the original physical properties are impaired. there were. For this reason, in order to improve hydrolysis resistance, it is important to make this carboxy terminal amount small.

[Alkali metal content]
The aromatic polyester used in the present invention preferably has an alkali metal content of 300 ppm or less based on the whole polyester. When the amount of the alkali metal is more than 300 ppm, the transparency and molecular weight of the resulting polyester may decrease, and the mechanical strength may decrease. Preferably it is 200 ppm or less, More preferably, it is 50 ppm or less. The “alkali metal” as used herein refers to the total amount of sodium metal and potassium metal, and the content of alkali metal can be measured by atomic absorption spectrometry.

<Polymer film>
[Method for producing polymer film]
The polymer film of the present invention is obtained by melt-extruding the above-mentioned aromatic polyester into a film shape, cooling and solidifying with a casting drum to obtain an unstretched film, and the obtained unstretched film at Tg to (Tg + 60) ° C. in the longitudinal direction and transverse direction. In each direction, the film is stretched biaxially at a magnification of 2.0 to 5.0 times, and can be molded by heat setting at a temperature of (Tm-100) to (Tm-5) ° C. for 1 to 100 seconds. Here, Tg represents the glass transition temperature of the aromatic polyester used, and Tm represents the melting point.
Stretching can be performed by a generally used method, for example, a method using a roll or a method using a stenter. The longitudinal direction and the transverse direction may be stretched simultaneously, and the longitudinal direction and the transverse direction may be stretched sequentially.

  Furthermore, a relaxation treatment may be performed if necessary. When the relaxation treatment is performed, it is effective to perform the treatment in a temperature range of (X-80) to X ° C. Here, X represents the heat setting temperature. The method of the relaxation treatment is not particularly limited, and even if any method is used, the reduction rate of the take-up side speed is set to 0.1 to 10% with respect to the supply side speed. It is preferable. The film after the relaxation treatment is adjusted so that the dimensional shrinkage after heating at 150 ° C. for 30 minutes is less than 0.1% in both the longitudinal direction of the film and the direction perpendicular to the longitudinal direction. Is more preferable. Such a film can suppress deformation of the film substrate even in a high-temperature treatment process in a display manufacturing process, and as a result, a high-definition panel can be manufactured.

[Thickness of polymer film]
The thickness of the polymer film constituting the transparent conductive film of the present invention is preferably in the range of 12 to 250 μm, more preferably 25 to 200 μm, and particularly preferably 38 to 150 μm. When the thickness of the film is less than 12 μm, the insulating performance of the film is insufficient, and the bending rigidity as a film for a display electrode substrate may be insufficient. On the other hand, when the thickness of the film exceeds 250 μm, the film has insufficient bending resistance, and when an external force is applied, the film may be cracked or may not return in a folded state.

[Coating layer]
An application layer for improving adhesiveness may be laminated on at least one surface of the polymer film constituting the transparent conductive film of the present invention. As such a coating layer, many have been proposed so far. For example, for a film having a relatively high polarity represented by polyester, a water-soluble or water-dispersible polyester resin or acrylic resin is used. Can be applied. Further, various fine particles may be added to the coating layer as necessary to impart slipperiness to the polymer film.
The thickness of the coating layer is preferably 0.01 to 0.2 μm, more preferably 0.02 to 0.1 μm.

<Transparent conductive layer>
[Material of transparent conductive layer]
A known metal film, metal oxide film, or the like can be applied to the transparent conductive layer constituting the transparent conductive film of the present invention. In particular, at least one metal oxide selected from the group consisting of indium oxide, cadmium oxide, tin oxide, zinc oxide, and titanium oxide in terms of transparency, conductivity, and mechanical properties. A membrane is preferred.

  As such a metal oxide film, for example, tin, tellurium, cadmium, molybdenum, tungsten, fluorine, zinc, germanium added indium oxide, cadmium oxide, and tin oxide as impurities, aluminum as impurities Zinc oxide and titanium oxide films to which is added. Among these, a transparent conductive layer containing indium oxide as a main component and containing 2 to 20% by mass of tin oxide and / or 2 to 20% by mass of zinc oxide is preferable because it is particularly excellent in transparency and conductivity.

  In addition, when the transparent conductive film of the present invention is used for organic EL, in order to improve the luminous efficiency by controlling the work function of the transparent conductive layer, it is mainly composed of indium oxide, tin oxide and zinc oxide. Elements other than tin and zinc may be further added to those containing one or more oxides selected from the group consisting of materials.

[Method for forming transparent conductive layer]
A method for forming the transparent conductive layer is not particularly limited, but a sputtering method is mainly used. A direct current sputtering method, a direct current magnetron sputtering method, a high frequency magnetron sputtering method, an ion beam sputtering method, and the like can be applied. From the viewpoint of productivity, the direct current magnetron sputtering method is preferably employed.

[Thickness of transparent conductive layer]
The film thickness of the transparent conductive layer is preferably 10 to 500 nm in order to obtain sufficient conductivity. If it is less than 10 nm, it is difficult to obtain sufficient electrical conductivity, and if it exceeds 500 nm, the surface smoothness deteriorates, so even if the above polymer film is sufficiently excellent in smoothness, it is good. Surface smoothness will be impaired.

<Transparent conductive film>
[Physical properties of transparent conductive film]
(Temperature expansion coefficient)
As for the transparent conductive film of this invention, it is preferable that the temperature expansion coefficient ((alpha) t) in the process of 30-100 degreeC is the range of 3-19 ppm / degreeC. The lower limit of the temperature expansion coefficient in the present invention is preferably 1 ppm / ° C. When the temperature expansion coefficient is less than the lower limit or exceeds the upper limit, the thermal deformation of the film in the display processing step is deteriorated, and problems such as warpage may occur.
The temperature expansion coefficient in the present invention is a temperature dimensional change curve obtained by measuring from 30 ° C. to 180 ° C. at a rate of temperature increase of 10 ° C./min using a thermomechanical analyzer (TMA). The temperature expansion coefficient is obtained from a 100 ° C. slope.

(Humidity expansion coefficient)
The transparent conductive film of the present invention preferably has a humidity expansion coefficient (αh) in the range of 2 to 5 ppm /% RH.

(Oxygen permeability coefficient / water vapor permeability coefficient)
The transparent conductive film of the present invention has an oxygen permeability coefficient of 0.3 cc · mm / m ² · 24 h · atm or less and a water vapor permeability coefficient of 0.3 g · mm / m ² · 24 h or less. It is preferable because it has gas barrier properties.

(Total light transmittance)
The transparent conductive film of the present invention preferably has a total light transmittance of 80% or more in the visible light region, and more preferably 85% or more. If it is less than 80%, problems such as a reduction in visibility may occur.

[Other layers]
The transparent conductive film of the present invention is a cross-linked polymer layer such as a gas barrier layer that prevents intrusion of oxygen and moisture, a hard coat layer for imparting scratch resistance, etc. on at least one surface of the polymer film, if necessary. Can be formed.
Examples of the gas barrier layer are not particularly limited, and various materials used for the transparent conductive film can be applied. Among them, an inorganic material mainly composed of Si oxide, nitride, or oxynitride is preferable because of its excellent transparency and gas barrier properties.

  Further, the method for producing the gas barrier layer is not particularly limited, and examples thereof include vapor deposition methods such as sputtering, vacuum deposition, ion plating, and plasma CVD. These gas barrier layers can be formed by setting them to a thickness capable of expressing the target performance, alone or in combination of two or more. In particular, when an inorganic thin film material is used as the gas barrier layer, the film thickness is preferably in the range of 2 nm to 1 μm.

  For the crosslinked polymer layer for imparting scratch resistance, a polysiloxane resin crosslinked structure, an acrylic resin crosslinked structure, an epoxy resin crosslinked structure, etc. should be used by a known coating method and curing method. Can be formed. Among them, it is preferable to use an acrylic resin containing an acryloyl group particularly from the viewpoint of reactivity.

Such a crosslinked polymer layer is also intended to impart durability to solvents and chemicals during panel assembly, and has sufficient alkali resistance, acid resistance, and stability to organic solvents such as N-methylpyrrolidone. It is preferable to appropriately select materials that can be secured and curing conditions.
The film thickness of the crosslinked polymer layer can be appropriately selected from the range of 0.01 to 20 μm.

  EXAMPLES Hereinafter, although an Example etc. are given and this invention is demonstrated further more concretely, this invention is not limited at all by this Example. In the examples, “part” and “%” are based on “mass” unless otherwise specified.

<Measurement method>
In Examples and Comparative Examples, the following items were measured and evaluated by the following methods.

(1) Intrinsic viscosity of polyester A polymer is dissolved in a mixed solvent of P-chlorophenol / tetrachloroethane (40/60 mass ratio) to prepare a solution having a polymer concentration of 0.5 g / dL, and measured at 35 ° C. It was.

(2) Glass transition point and melting point Using a DSC (manufactured by TA Instruments, trade name: DSC2920 modulated DSC), the glass transition point and the melting point were measured at a heating rate of 20 ° C./min.

(3) Terminal carboxy group concentration It measured by 1H-NMR of 600 MHz (manufactured by JEOL Ltd., trade name: JEOL A-600).

(4) Esterification rate It calculated | required by the following formula using the terminal carboxy group density | concentration obtained above.

(5) Alkali metal content The total amount of sodium metal and potassium metal was measured on the basis of the mass of the resin composition by using a polarized Zeeman atomic absorption photometer: Z5000 manufactured by Hitachi, Ltd.

(6) Film thickness It measured using the Anritsu company make and an electronic micro.

(7) Total light transmittance It measured using Nippon Denshoku Industries Co., Ltd. brand name: COH-300A.

(8) Water vapor barrier property The water vapor permeability in a 40% C, 90% RH atmosphere was measured using a product name: Permatran W1A manufactured by MOCON, and the water vapor permeability coefficient was calculated from the film thickness of the sample.

(9) Oxygen barrier property The oxygen permeability under the atmosphere of 23 ° C., 0% RH, and 40 ° C., 90% RH was measured using a product name: Oxytolane 2/20 ML manufactured by MOCON.

(10) Temperature expansion coefficient (αt)
The obtained transparent conductive film was cut into a length of 15 mm and a width of 5 mm so that the width direction of the film would be the measurement direction, set in TMA3000 manufactured by Vacuum Riko, and 30 at 60 ° C. under a nitrogen atmosphere (0% RH). The sample was pretreated for minutes and then cooled to room temperature. Subsequently, the temperature was raised from 25 ° C. to 70 ° C. at 2 ° C./min, the sample length at each temperature was measured, and the temperature expansion coefficient (αt) was calculated from the following equation. Note that the measurement direction is the longitudinal direction of the cut sample, five measurements were performed, and the average value was taken as the temperature expansion coefficient (αH).
αt = {(L ⁶⁰ −L ⁴⁰ )} / (L ⁴⁰ × ΔT)} + 0.5
Here, L ⁴⁰ in the above formula is the sample length (mm) at 40 ° C., L ⁶⁰ is the sample length (mm) at 60 ° C., ΔT is 20 (= 60-40) ° C., 0.5 Is the temperature expansion coefficient (αt) of quartz glass (× 10 ⁻⁶ / ° C.).

(11) Humidity expansion coefficient (αh)
The obtained transparent conductive film was cut into a length of 15 mm and a width of 5 mm so that the width direction of the film would be the measurement direction, set in TMA3000 manufactured by Vacuum Riko, and a humidity of 30% RH in a nitrogen atmosphere at 30 ° C. The length of each sample at a humidity of 70% RH was measured, and the humidity expansion coefficient (αh) was calculated by the following equation. In addition, the measurement direction is the longitudinal direction of the sample cut out, five measurements were performed, and the average value was defined as the humidity expansion coefficient (αh).
αh = (L ⁷⁰ −L ³⁰ ) / (L ³⁰ × ΔH)
Here, L ³⁰ in the above formula is a sample length (mm) when 30% RH, L ⁷⁰ is a sample length (mm) when 70% RH, ΔH: 40 (= 70-30)% RH is there.

(12) Water absorption rate It estimated from the mass change after immersing a film in 25 degreeC water for 24 hours by the method based on ASTMD570.

<Production Example 1>
[Production of bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) g-2-naphthoic acid (NEO-EG)]
Autoclave provided with 1 L stirrer and nitrogen gas inlet for 100 parts by mass of 6,6 ′-(ethylenedioxy) di-2-naphthoic acid, 62 parts by mass of ethylene glycol, and 0.085 parts by mass of tetra-n-butyl titanate Then, after nitrogen substitution, a nitrogen pressure of 0.2 MPa was applied, and the reaction was performed at a temperature of 230 ° C. for 6 hours. After the reaction, the precipitated crystals were filtered and washed with methanol. After washing, vacuum drying at 120 ° C. yielded 115 parts by weight of bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) G-2-naphthoic acid (NEO-EG). The obtained bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) di-2-naphthoic acid (NEO-EG) had an esterification degree of 96% and a melting point of 240 ° C.

<Production Example 2>
100 parts by mass of bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) g-2-naphthoic acid (NEO-EG) obtained in Production Example 1, 0.0347 parts by mass of tetra-n-butyl titanate, A reactor with a rectifying column was charged and melted at 270 ° C. under nitrogen. Thereafter, the pressure was gradually reduced, and after stirring and reaction at 500 mmHg for about 20 minutes, the polymerization temperature was raised to 320 ° C. Next, the system was gradually depressurized, and after reaching 0.2 mmHg, an aromatic polyester was obtained by stirring reaction for about 20 minutes.
The obtained aromatic polyester had an intrinsic viscosity of 1.47, a glass transition temperature of 132 ° C., and a melting point of 300 ° C. When the diethylene glycol component was measured by NMR, 5.0 mol% of the diethylene glycol component was contained. The terminal carboxy group concentration was 55 eq / Ton, and the alkali metal content was 27 ppm.

<Production Example 3>
Bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) di-2-naphthoic acid 100 parts by mass (NEO-EG), 2,6-bis (hydroxyethoxycarbonyl) naphthalene 27 obtained in Production Example 1 Part by mass, 0.02 part by mass of tetra-n-butyl titanate were charged into a reactor equipped with a rectifying column and melted at 270 ° C. under nitrogen. Thereafter, the pressure was gradually reduced, and after stirring and reaction at 500 mmHg for about 20 minutes, the polymerization temperature was raised to 320 ° C. Next, the system was gradually depressurized, and after reaching 0.2 mmHg, an aromatic polyester was obtained by stirring reaction for about 20 minutes.
The obtained aromatic polyester had an intrinsic viscosity of 1.6, a glass transition temperature of 121 ° C., and a melting point of 287 ° C. When the diethylene glycol component was measured by NMR, 6.0 mol% diethylene glycol component was contained. The terminal carboxy group concentration was 92 eq / Ton, and the alkali metal content was 20 ppm.

<Production Example 4>
100 parts by mass of bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) di-2-naphthoic acid (NEO-EG) obtained in Production Example 1, 9.2 parts by mass of bis (hydroxyethyl) terephthalate, 0.04 parts by mass of tetra-n-butyl titanate was charged into a reactor equipped with a rectifying column and melted at 270 ° C. under nitrogen. Thereafter, the pressure was gradually reduced, and after stirring and reaction at 500 mmHg for about 20 minutes, the polymerization temperature was raised to 320 ° C. Next, the system was gradually depressurized, and after reaching 0.2 mmHg, an aromatic polyester was obtained by stirring reaction for about 20 minutes.
The obtained aromatic polyester had an intrinsic viscosity of 1.4, a glass transition temperature of 120 ° C., and a melting point of 282 ° C. When the diethylene glycol component was measured by NMR, 7.2 mol% of the diethylene glycol component was contained. The terminal carboxy concentration was 80 eq / Ton, and the alkali metal content was 23 ppm.

<Production Example 5>
By subjecting dimethyl terephthalate, 6,6 ′-(ethylenedioxy) di-2-naphthoic acid and ethylene glycol to esterification and transesterification in the presence of titanium tetrabutoxide, followed by polycondensation reaction, Aromatic polyester was obtained.
The obtained aromatic polyester had an intrinsic viscosity of 0.73 dl / g, 65 mol% of the acid component was terephthalic acid component, and 35 mol% of the acid component was 6,6 ′-(ethylenedioxy) di-2-naphtho. Of the acid component and glycol component, 98.5 mol% was an ethylene glycol component, and 1.5 mol% was a diethylene glycol component. Moreover, melting | fusing point was 233 degreeC and glass transition temperature was 91 degreeC.
In addition, before the polycondensation reaction, the polyester contained silica particles having an average particle size of 0.5 μm so as to be 0.2% by mass based on the mass of the obtained resin composition.

<Production Example 6>
Dimethyl terephthalate, 6,6 ′-(ethylenedioxy) di-2-naphthoic acid, and ethylene glycol are esterified and transesterified in the presence of titanium tetrabutoxide, followed by polycondensation. As a result, an aromatic polyester was obtained.
The obtained aromatic polyester had an intrinsic viscosity of 0.68 dl / g, 80 mol% of the acid component was terephthalic acid component, and 20 mol% of the acid component was 6,6 ′-(ethylenedioxy) di-2-naphtho. 98 mol% of the acid component and the glycol component were the ethylene glycol component, and 2 mol% was the diethylene glycol component. Moreover, melting | fusing point was 230 degreeC and the glass transition temperature was 85 degreeC.
In addition, before the polycondensation reaction, the polyester contained silica particles having an average particle size of 0.5 μm so as to be 0.2% by mass based on the mass of the obtained resin composition.

<Production Example 7>
Dimethyl 2,6-naphthalenedicarboxylate, 6,6 ′-(ethylenedioxy) di-2-naphthoic acid, and ethylene glycol were subjected to esterification and transesterification in the presence of titanium tetrabutoxide, followed by An aromatic polyester was obtained by polycondensation reaction.
The obtained aromatic polyester has an intrinsic viscosity of 0.78 dl / g, 73 mol% of the acid component is 2,6-naphthalenedicarboxylic acid component, and 27 mol% of the acid component is 6,6 ′-(ethylenedioxy). Of the di-2-naphthoic acid component and glycol component, 98.5 mol% was an ethylene glycol component, and 1.5 mol% was a diethylene glycol component. The melting point was 240 ° C and the glass transition temperature was 112 ° C.
Before the polycondensation reaction, the polyester contained silica particles having an average particle size of 0.5 μm so as to be 0.2% by mass based on the mass of the obtained resin composition.

<Example 1>
[Production of film]
The aromatic polyester obtained in Production Example 2 was dried at 180 ° C. for 5 hours, melt-extruded at 315 ° C., and rapidly cooled and solidified on a casting drum maintained at 40 ° C. to obtain an unstretched film.
The obtained unstretched film was stretched 4.0 times in the longitudinal direction at a temperature of 140 ° C. between two rolls having a speed difference to obtain a uniaxially stretched film. Next, this uniaxially stretched film was stretched by 3.0 times in the transverse direction while increasing the temperature to 130 to 160 ° C. in the traveling direction of the film, and then at 210 ° C. in the final heat setting zone. A biaxially oriented polymer film was obtained by performing a heat setting treatment for 1 minute. The resulting polymer film had a thickness of 100 μm.

[Formation of transparent conductive layer]
A transparent conductive film was obtained by forming an indium-tin oxide (ITO) layer having a thickness of 120 nm on one surface of the obtained polymer film by a DC magnetron sputtering method. Table 1 shows the evaluation results of the obtained transparent conductive film.

<Example 2>
[Production of film]
A biaxially oriented polymer film was obtained in the same manner as in Example 1 except that the aromatic polyester obtained in Production Example 3 was melt-extruded at 300 ° C.

[Formation of crosslinked polymer layer and formation of transparent conductive layer]
By forming a cross-linked polymer layer with a thickness of 4 μm on both surfaces of the obtained polymer film, and subsequently forming an indium-tin oxide (ITO) layer in the same manner as in Example 1, a transparent conductive film was obtained. Obtained. Table 1 shows the evaluation results of the obtained transparent conductive film.
Here, in forming the crosslinked polymer layer, 20 parts by mass of dimethylol tricyclodecane diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: light acrylate DCP-A), urethane acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: NK Oligo U-15HA) is mixed with 10 parts by mass, 30 parts by mass of 1-methoxy-2-propanol and 2 parts by mass of 1-hydroxycyclohexyl phenyl ketone as an initiator. After coating on the surface of the film and heating at 60 ° C. for 1 minute, photocuring was performed using a high-pressure mercury lamp at an integrated light quantity of 700 mJ / m ² .

<Example 3>
A transparent conductive film was obtained in the same manner as in Example 2 except that a silicon oxide film having a thickness of 30 nm was formed directly under the indium-tin oxide (ITO) layer by DC magnetron reactive sputtering. It was. Table 1 shows the evaluation results of the obtained transparent conductive film.

<Example 4>
[Production of film]
The aromatic polyester obtained in Production Example 5 was supplied to an extruder and extruded from a die at 290 ° C. in a molten state onto a cooling drum having a rotating temperature of 40 ° C. to form an unstretched film. Subsequently, between two pairs of rollers having different rotation speeds along the film forming direction, the film surface temperature is heated from above by an IR heater so that the film surface temperature becomes 110 ° C., and the draw ratio in the film forming direction (MD) is 4. The film was stretched at 0 times to obtain a uniaxially stretched film. The resulting uniaxially stretched film was guided to a stenter, stretched at 120 ° C. in the width direction (TD) at a stretch ratio of 4.5 times, and then heat-fixed at 210 ° C. for 3 seconds to obtain a thickness of 10 μm. A biaxially oriented polymer film was obtained.

[Formation of transparent conductive layer]
As in Example 1, an indium-tin oxide (ITO) layer having a thickness of 120 nm was formed on one side of the obtained polymer film. Table 1 shows the evaluation results of the obtained transparent conductive film.

<Example 5>
Production Example 6 The obtained polyester was supplied to an extruder and extruded from a die at 290 ° C. in a molten state onto a cooling drum having a rotating temperature of 30 ° C. to form an unstretched film. Subsequently, between two sets of rollers with different rotation speeds along the film forming direction (MD), the film surface temperature is heated to 105 ° C. with an IR heater from above and stretched in the film forming direction (MD). The film was stretched at a magnification of 5.0 to obtain a uniaxially stretched film. The obtained uniaxially stretched film was guided to a stenter and stretched at 115 ° C. in the width direction (TD) at a stretch ratio of 5.0 times, and then heat-fixed at 210 ° C. for 3 seconds to obtain a thickness of 10 m. A biaxially oriented polymer film was obtained.

[Formation of transparent conductive layer]
As in Example 1, an indium-tin oxide (ITO) layer having a thickness of 120 nm was formed on one side of the obtained polymer film. Table 1 shows the evaluation results of the obtained transparent conductive film.

<Example 6>
The polyester obtained in Production Example 7 was supplied to an extruder and extruded from a die at 300 ° C. in a molten state onto a cooling drum having a rotating temperature of 45 ° C. to form an unstretched film. Subsequently, between two sets of rollers with different rotation speeds along the film forming direction (MD), the film is heated from above with an IR heater so that the film surface temperature becomes 130 ° C. and stretched in the film forming direction (MD). The film was stretched at a magnification of 4.0 to obtain a uniaxially stretched film. The resulting uniaxially stretched film was guided to a stenter, stretched at 140 ° C. in the width direction (TD) at a stretch ratio of 6.0 times, and then heat-fixed at 200 ° C. for 10 seconds to obtain a thickness of 7 μm. A biaxially oriented polymer film was obtained.

[Formation of transparent conductive layer]
As in Example 1, an indium-tin oxide (ITO) layer having a thickness of 120 nm was formed on one side of the obtained polymer film. Table 1 shows the evaluation results of the obtained transparent conductive film.

<Comparative Example 1>
In Production Example 7, instead of bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) di-2-naphthoic acid (NEO-EG), an equimolar amount of 2,6-bis (hydroxyethoxycarbonyl) Polyester was polymerized using naphthalene, and a transparent conductive film was obtained in the same manner as in Example 1. As shown in Table 1, the obtained transparent conductive film was inferior in dimensional stability and barrier properties.

<Comparative example 2>
Polyester using an equimolar amount of bis (hydroxyethyl) terephthalate instead of bis (β-hydroxyethyl) 6,6 ′-(ethylenedioxy) g-2-naphthoic acid (NEO-EG) in Production Example 6 And a transparent conductive film was obtained in the same manner as in Example 1. As shown in Table 1, the obtained transparent conductive film was inferior in dimensional stability and barrier properties.

  The transparent conductive film of the present invention is used as an electrode substrate for liquid crystal display elements, photoconductive photoreceptors, surface light emitters, inorganic and organic EL elements, electrophoresis, field emission elements, plasma elements, surface heating elements, touch panels and the like. It can be used beneficially.

Claims (8)

A transparent conductive layer is formed on at least one surface of a polymer film mainly composed of an aromatic polyester containing an acid component represented by the following formula (1) and a diol component represented by the following formula (2). Transparent conductive film.

(In the formula, ^RA is an alkylene group having 2 to 10 carbon atoms.)

(In the formula, R ^C is an alkylene group having 2 to 10 carbon atoms.) The acid component contains 50 mol% or more and 100 mol% or less of the repeating unit represented by the formula (1), and contains 0 mol% or more and 50 mol% or less of the repeating unit represented by the following formula (3). The transparent conductive film according to claim 1.

(In the formula, R ^B is a phenylene group or a naphthalenediyl group.) The acid component contains 5 mol% or more and less than 50 mol% of the repeating unit represented by the above formula (1), and the repeating unit represented by the following formula (3) exceeds 50 mol% and is 95 mol%. The transparent conductive film according to claim 1, comprising:

(In the formula, R ^B is a phenylene group or a naphthalenediyl group.) The transparent conductive film according to any one of claims 1 to 3, wherein the repeating unit represented by the formula (1) is represented by the following formula (4).

  The transparent conductive layer is at least one metal oxide film selected from the group consisting of indium oxide, cadmium oxide, tin oxide, zinc oxide, and titanium oxide. Transparent conductive film.   The transparent conductive film according to any one of claims 1 to 5, wherein a temperature expansion coefficient is in a range of 3 to 19 ppm / ° C.   The transparent conductive film according to any one of claims 1 to 6, wherein the humidity expansion coefficient is in the range of 2 to 5 ppm /% RH.   The transparent conductive film according to claim 1, wherein a layer having gas barrier properties and / or a crosslinked polymer layer is laminated on at least one surface of the polymer film.