JP6620483B2 - Cycloolefin film - Google Patents

Description

  The present invention relates to a cycloolefin film. More specifically, the present invention relates to a cycloolefin-based film having high adhesion to a transparent conductive layer when used as a base material for a touch panel, excellent keystroke durability in durability tests such as high temperature and high humidity, and reduced display unevenness.

  In recent years, touch panel technology for inputting information by touching with a finger or the like is known.

  There are various types of touch panels that detect contact with a finger or the like, and a capacitive type is widely used as a device that requires multipoint detection, such as a smartphone. The capacitive touch panel includes, for example, an electrode pattern using a matrix-like transparent conductive layer in the detection surface, and detects a change in capacitance at a position touched by a finger or the like.

  As the base material of the touch panel, a glass base material has been conventionally used because the process temperature when forming the transparent conductive layer is relatively high. While the touch panel using the glass substrate has high durability against touch panel production, it is difficult to reduce the thickness of the touch panel, and there is a problem that the function stops due to breakage during transportation and glass breakage during operation of the touch panel-equipped terminal. .

  In order to solve the above problems, it has been considered to replace the transparent conductive film using a resin base material or the like as the base material.

  However, a thin transparent conductive film is more susceptible to deterioration of the transparent conductive layer due to contact with a finger or a touch pen than a touch panel using a conventional glass substrate, and durability against keystroke (hereinafter referred to as keystroke durability). It was difficult to give it.

  With respect to the above problem, in Patent Document 1, a conductive film is provided so as to be electrically connected to the electrode pattern on the same surface of the base film on which the electrode pattern is provided and in a non-display area. Has disclosed a technique for improving the keying durability by controlling the thickness of the routing wiring having the keying durability, but the keying durability was insufficient.

  On the other hand, Patent Document 2 discloses a cycloolefin-based resin film containing a UV absorber having a specific molecular weight and produced by a melt film-forming method using a touch roll. However, if a substrate prepared by this manufacturing method is used, even if a very small amount of the ultraviolet absorber is used, it may contaminate the process when used for a long period of time, and ultraviolet rays may be applied to the film surface in endurance tests such as high temperature and high humidity. It was found that the microcrystal of the absorbent has a problem in keying durability as a transparent conductive film, and display unevenness occurs due to keying.

JP 2013-214173 A JP 2008-274266 A

  The present invention has been made in view of the above-mentioned problems and situations, and its solution is high adhesion to a transparent conductive layer when used as a base material for a touch panel, and in durability tests such as high temperature and high humidity. An object of the present invention is to provide a cycloolefin film having excellent keystroke durability and reduced display unevenness.

In order to solve the above problems, the present inventor contains a cycloolefin polymer having a specific structure in the process of examining the cause of the above problems, and includes an aromatic solvent, a halide solvent, and a non-aromatic solvent. System solvents (excluding halide solvents) in a specific residual solvent amount range, and the solubility parameter value (SP value) of the non-aromatic solvent and the non-aromatic solvent When used as a touch panel substrate, the cycloolefin-based film with a surface tension value of the solvent within a specific range provides high adhesion to the transparent conductive layer, and provides keystroke durability in durability tests such as high temperature and high humidity. It has been found that a cycloolefin-based film that is excellent and has reduced display unevenness can be obtained.

  That is, the said subject which concerns on this invention is solved by the following means.

1. A cycloolefin film containing at least a cycloolefin polymer having a polar group, wherein an aromatic solvent is in the range of 50 to 300 ppm, a halide solvent is in the range of 300 to 800 ppm, and non- An aromatic solvent (excluding halide solvents) is contained within a range of 300 to 6000 ppm, and the solubility parameter value (SP value) of the non-aromatic solvent is 15 to 25 ((MPa) ^{1 / 2} ), and the surface tension value of the non-aromatic solvent is in the range of 20 to 25 (mN / m).

  2. The cycloolefin film according to item 1, wherein the content of the non-aromatic solvent is in the range of 800 to 3000 ppm.

  3. The cycloolefin film according to Item 1 or 2, wherein the cycloolefin polymer is composed of a cycloolefin monomer having a structure represented by General Formula (A-2).

（一般式（Ａ−２）中、Ｒ^５は、独立に水素原子、炭素数１〜５の炭化水素基、又は炭素数１〜５のアルキル基を有するアルキルシリル基を表す。Ｒ^６は、カルボキシ基、ヒドロキシ基、アルコキシカルボニル基、アリルオキシカルボニル基、アミノ基、アミド基、シアノ基、フッ素原子、塩素原子、臭素原子、又はヨウ素原子を表す。ｐは、０〜２の整数を表す。）
４．さらに、前記溶解度パラメータ値（ＳＰ値）が２５（（ＭＰａ）^１／２）を超える非芳香族系の溶媒を含有することを特徴とする第１項から第３項までのいずれか一項に記載のシクロオレフィン系フィルム。

(In General Formula (A-2), R ⁵ independently represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkylsilyl group having an alkyl group having 1 to 5 carbon atoms. R ⁶ represents A carboxy group, a hydroxy group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and p represents an integer of 0 to 2. )
4). Furthermore, the solubility parameter value (SP value) contains a non-aromatic solvent exceeding 25 ((MPa) ^1/2 ), according to any one of items 1 to 3, The cycloolefin film described.

  5). The non-aromatic solvent is selected from isopropanol, octane, acetone, ethyl formate, 1-butanol, ethyl acetate, and cyclohexane, according to any one of items 1 to 4. Cycloolefin film.

  By using the above means of the present invention, when used as a base material for a touch panel, the cycloolefin film has high adhesion to a transparent conductive layer, excellent keystroke durability in durability tests such as high temperature and high humidity, and reduced display unevenness. Can be provided.

  The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.

  In the thin transparent conductive film, the reason why the durability against keystroke is lowered is considered as follows. That is, since the transparent conductive layer is easily affected by minute film thickness deviations and minute scratches, the substrate film is subjected to a lot of load at the time of keystroke in durability tests such as high temperature and high humidity. It is presumed that the conductivity deteriorates due to a decrease in adhesion between the transparent conductive layers. In addition, the display on the panel is likely to be uneven due to the deterioration of conductivity.

  As a result of studying the present inventors, the cycloolefin-based film containing a solvent having the above-mentioned specific configuration as a residual solvent with respect to a cycloolefin-based film containing a cycloolefin-based polymer having a polar group was obtained. The polar group of the polymer can be localized on the film surface side, and since the polar group has a high surface energy, the adhesion force is increased by the interaction with the transparent conductive layer, and the adhesion is uneven. It is presumed that the decrease in keying resistance and the occurrence of display unevenness due to poor adhesion in the endurance test such as high temperature and high humidity were suppressed.

  That is, when a cycloolefin polymer having a polar group is formed using only dichloromethane, the film surface tends to maintain a more stable state with low surface energy. It is presumed that the adhesiveness with the transparent conductive layer is lowered because it is easy to take a structure in which the polar group is directed to the inside of the film on the film surface side and the surface energy is low.

  On the other hand, when the cycloolefin polymer is formed into a film using alcohol such as dichloromethane and ethanol, the solubility parameter value (SP value) of ethanol is as high as 26 or more, and the solubility parameter value (SP) of the cycloolefin polymer is high. Value) is too far from around 17, the compatibility with the resin is inferior, the polar group tends to be non-uniformly oriented, and the keystroke durability is deteriorated and display unevenness is caused by a decrease in adhesion with the transparent conductive layer. It is assumed that is likely to occur.

On the other hand, the solubility parameter value (SP value) according to the present invention is in the range of 15 to 25 ((MPa) ^1/2 ), and the surface tension value is in the range of 20 to 25 (mN / m). When a non-aromatic solvent is used instead of the alcohol solvent, compatibility with the resin is improved because it is close to the solubility parameter value (SP value) of the cycloolefin polymer, and the surface tension is relatively low. Since the solvent easily moves to the film surface, the polar group of the cycloolefin polymer is easily arranged on the film surface side, and the keystroke durability is deteriorated and the display unevenness is improved by improving the adhesion with the transparent conductive layer. Is presumed to have been improved.

Schematic diagram of an example of a dope preparation step, a casting step, a drying step and a winding step of a solution casting film forming method preferable for the present invention Schematic sectional view of a display device including an example of the configuration of a touch panel display device according to the present invention

The cycloolefin-based film of the present invention is a cycloolefin-based film containing at least a cycloolefin-based polymer having a polar group, an aromatic solvent within a range of 50 to 300 ppm, and a halide-based solvent. The solubility parameter value (SP value) of the non-aromatic solvent is contained within the range of 300 to 800 ppm, and the non-aromatic solvent (excluding the halide solvent) is contained within the range of 300 to 6000 ppm. Is in the range of 15 to 25 ((MPa) ^1/2 ), and the surface tension value of the non-aromatic solvent is in the range of 20 to 25 (mN / m). This feature is a technical feature common to the inventions according to claims 1 to 5.

  As an embodiment of the present invention, from the viewpoint of manifestation of the effect of the present invention, the content of the non-aromatic solvent is in the range of 800 to 3000 ppm, and the polar group of the cycloolefin polymer is a film. From the viewpoint of facilitating localization on the surface side, it is preferable.

  Moreover, the cycloolefin polymer having the polar group is composed of a cycloolefin monomer having the structure represented by the general formula (A-2). From the viewpoint of facilitating localization on the surface side, it is preferable.

Furthermore, in addition to the solvent, the inclusion of a non-aromatic solvent having a solubility parameter value (SP value) exceeding 25 ((MPa) ^1/2 ) alleviates the charging of the cycloolefin resin. From the viewpoint of forming a uniform and excellent adhesive layer in the coating process.

  Further, the non-aromatic solvent is selected from isopropanol, octane, acetone, ethyl formate, 1-butanol, ethyl acetate and cyclohexane, and the polar group of the cycloolefin polymer is localized on the film surface side. It is preferable from the viewpoint of facilitating conversion.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

<< Outline of cycloolefin film of the present invention >>
The cycloolefin-based film of the present invention is a cycloolefin-based film containing at least a cycloolefin-based polymer having a polar group, an aromatic solvent within a range of 50 to 300 ppm, and a halide-based solvent. The solubility parameter value (SP value) of the non-aromatic solvent is contained within the range of 300 to 800 ppm, and the non-aromatic solvent (excluding the halide solvent) is contained within the range of 300 to 6000 ppm. There is in the range of 15~25 ^{((MPa) 1/2),} the surface tension value of the solvent of the non-aromatic is being in the range of 20~25 (mN / m).

  In the present invention, a cycloolefin polymer having a polar group is added to an aromatic solvent or a halide solvent, a dope is prepared using a specific non-aromatic solvent, When the membrane method is used, the polar group of the cycloolefin polymer can be localized on the film surface side when the solvent is volatilized, and the polar group having a high surface energy and the transparent conductive layer can interact with each other. By improving the adhesive force with the polarizer by the action, it is possible to provide a cycloolefin-based film that has excellent keystroke durability in a durability test such as high temperature and high humidity and suppresses the occurrence of display unevenness.

  The amount of the solvent contained in the cycloolefin-based film of the present invention is a so-called residual solvent amount, and refers to the amount of solvent contained in the film after film production. The amount of the solvent can be quantified by headspace gas chromatography, which will be described later, and the measurement is a value when measured during a period from film production to film processing. Usually, after the film is manufactured and wound up, it is wrapped in a protective sheet or the like, stored in a semi-sealed state, and is in that state until it is processed, so the variation in the amount of residual solvent is small. Accordingly, the measurement of the residual solvent amount can determine whether the configuration of the present invention is based on the value measured during the period from the film manufacture to before the film processing.

  The aromatic solvent contained in the cycloolefin-based film of the present invention is in the range of 50 to 300 ppm, and if it is less than 50 ppm, the polar group on the substrate surface cannot be randomized and the surface protective layer, transparent If the adhesiveness with the conductive layer is inferior and exceeds 300 ppm, it is not preferable from the viewpoint of durability haze under high temperature and high humidity and environmental safety. More preferably, it is in the range of 50 to 150 ppm.

Similarly, the halide solvent is in the range of 300 to 800 ppm, and if it is less than 300 ppm, the polar group on the substrate surface cannot be randomized, and the adhesion to the surface protective layer and the transparent conductive layer is poor. If it exceeds 800 ppm, it is not preferable from the viewpoint of durability haze under high temperature and high humidity and environmental safety. More preferably, it is in the range of 300 to 500 ppm. Similarly, the non-aromatic solvent (excluding the halide solvent) is in the range of 300 to 6000 ppm. It cannot be randomized, and the adhesion to the surface protective layer and the transparent conductive layer is poor. If it exceeds 6000 ppm, the haze tends to increase under high temperature and high humidity, which is not preferable.

  The content of the non-aromatic solvent is preferably in the range of 800 to 3000 ppm from the viewpoint of easily localizing the polar group of the cycloolefin polymer on the film surface side.

Further, the solubility parameter values of non-aromatic solvent (SP value) is in the range of 15-25 ^{((MPa) 1/2),} is less than 15 ^{((MPa) 1/2),} aromatic Since the SP value is far away from the solvent and the halide solvent, the haze tends to increase under high temperature and high humidity. If it exceeds 25 ((MPa) ^1/2 ), the SP value with the resin increases. Since it leaves | separates, it exists in the tendency for a haze to raise under high temperature, high humidity, and is not preferable. More preferably, it is in the range of 18 to 24 ((MPa) ^1/2 ).

Similarly, the surface tension value of the non-aromatic solvent is in the range of 20 to 25 (mN / m), and if it is less than 20 (mN / m), the non-aromatic solvent is present on the substrate surface. Adhesion is inferior because it lowers the surface energy when localized, and if it exceeds 25 (mN / m), it will not be localized on the substrate surface, and the polar group orientation of the cycloolefin resin cannot be randomized, It is not preferable. More preferably, it is in the range of 21 to 24 (mN / m). For the above-described method for determining the solvent content, the method for measuring the solubility parameter value (SP value) of the solvent, and the method for measuring the surface tension of the solvent, It is preferable to adopt this method.

[Method for quantifying solvent content]
The solvent content in the cycloolefin film can be quantified by headspace gas chromatography.

  In the headspace gas chromatography method, a sample is sealed in a container, heated, and the gas in the container is quickly injected into the gas chromatograph while the container is filled with volatile components, and mass spectrometry is performed to identify the compound. The volatile components are quantified while performing. In the headspace method, it is possible to observe all peaks of volatile components by gas chromatography, and to quantify volatile substances and monomers with high accuracy by using an analysis method using electromagnetic interaction. It can be done together. The following apparatus can be used as an example.

Headspace device: HP7694 Head Space Sampler (manufactured by Hewlett-Packard Company)
Temperature conditions: transfer line 200 ° C, loop temperature 200 ° C
Sample amount: 0.8 g / 20 ml vial GC: HP5890 (manufactured by Hewlett-Packard Company)
MS: HP5971 (manufactured by Hewlett-Packard Company)
Column: HP-624 (30 m x inner diameter 0.25 mm)
Oven temperature: initial temperature 40 ° C. (holding time 3 minutes), heating rate 10 ° C./min, ultimate temperature 200 ° C. (holding time 5 minutes)
[Measurement Method of Solvent Solubility Parameter Value (SP Value)]
The “solubility parameter (SP value)” referred to in the present application is a value represented by the square root of the molecular aggregation energy, and is described in Polymer Hand Book (Second Edition) Chapter IV, Solubility Parameter Values. However, in this application, a unit is (MPa) ^1/2 and shows the value in 25 degreeC.

  In addition, R.D. F. It can be calculated by the method described in Fedors, Polymer Engineering Science, 14, p147 (1974). That is, it can be basically calculated according to the following formula.

Solubility parameter value (SP value) = (ΔE / V) ^1/2
Here, ΔE represents the cohesive energy density. V represents molecular volume.

  For example, the solubility parameter value (SP value) of the solvent according to the present invention is the above-mentioned R.I. F. Based on the concept of Fedors, Scigress Explorer Ver. It can be calculated using 2.4 (manufactured by Fujitsu Limited).

[Method for measuring surface tension of solvent]
Although the measurement of the surface tension of the solvent which concerns on this application is not specifically limited, It is a measured value in 25 degreeC measurement, and a unit is (mN / m).

  As a surface tension measuring method, a ring method (du Nouy method), a plate method (Wilhelmy method), and the like are known, but it is preferable to measure by an automatic surface tension meter using a plate method (Wilhelmy method).

  As a commercially available surface tension meter, measuring devices such as “DyneMaster” series, DY200, 300, 500, 700 manufactured by Kyowa Interface Science Co., Ltd. can be used.

<Configuration of cycloolefin film of the present invention>
[1] Cycloolefin resin (cycloolefin polymer)
As the cycloolefin resin, polymers of various cycloolefin monomers can be used, but it is preferable to use a polymer obtained by homopolymerization or copolymerization of a cycloolefin monomer having a norbornene skeleton. .

  Hereinafter, the cycloolefin monomer used in the present invention will be described.

  The cycloolefin resin according to the present invention is a polymer obtained by homopolymerization or copolymerization from cycloolefin monomers represented by the following general formulas (A-1) and (A-2). It is preferable. In particular, a cycloolefin resin having a structure represented by the general formula (A-2) is preferable from the viewpoint of easily localizing the polar group of the resin on the film surface side.

  The cycloolefin monomer which has a structure represented by general formula (A-1) is demonstrated.

（一般式（Ａ−１）中、Ｒ^１〜Ｒ^４は、それぞれ独立に水素原子、ハロゲン原子、酸素、窒素、イオウ又はケイ素を含む連結基を有していてもよい置換又は非置換の炭素原子数１〜３０の炭化水素基；又は極性基を表す。ｐは、０〜２の自然数を表す。）
上記極性基としては、カルボキシ基、ヒドロキシ基、アルコキシカルボニル基、アリルオキシカルボニル基、アミノ基、アミド基、シアノ基などが挙げられ、これら極性基はメチレン基などの連結基を介して結合していてもよい。また、カルボニル基、エーテル基、シリルエーテル基、チオエーテル基、イミノ基など極性を有する２価の有機基が連結基となって結合している炭化水素基なども極性基として挙げられる。これらの中では、カルボキシ基、ヒドロキシ基、アルコキシカルボニル基又はアリルオキシカルボニル基が好ましく、特にアルコキシカルボニル基又はアリルオキシカルボニル基であることが、溶液製膜時の溶解性を確保する観点で好ましい。

(In General Formula (A-1), R ^{1 to} R ⁴ are each independently substituted or unsubstituted carbon which may have a linking group containing a hydrogen atom, a halogen atom, oxygen, nitrogen, sulfur or silicon. Represents a hydrocarbon group having 1 to 30 atoms; or represents a polar group, and p represents a natural number of 0 to 2.)
Examples of the polar group include a carboxy group, a hydroxy group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group, and a cyano group, and these polar groups are bonded through a linking group such as a methylene group. May be. In addition, a hydrocarbon group in which a divalent organic group having a polarity such as a carbonyl group, an ether group, a silyl ether group, a thioether group, or an imino group is bonded as a linking group can also be exemplified. Among these, a carboxy group, a hydroxy group, an alkoxycarbonyl group, or an allyloxycarbonyl group is preferable, and an alkoxycarbonyl group or an allyloxycarbonyl group is particularly preferable from the viewpoint of ensuring solubility during solution film formation.

  Next, the cycloolefin monomer represented by General Formula (A-2), which is preferable in the present invention, will be described.

（一般式（Ａ−２）中、Ｒ^５は、独立に水素原子、炭素数１〜５の炭化水素基、又は炭素数１〜５のアルキル基を有するアルキルシリル基を表す。Ｒ^６は、カルボキシ基、ヒドロキシ基、アルコキシカルボニル基、アリルオキシカルボニル基、アミノ基、アミド基、シアノ基、フッ素原子、塩素原子、臭素原子、又はヨウ素原子を表す。ｐは、０〜２の整数を表す。）
本発明においては、一般式（Ａ−２）で表されるように、置換基Ｒ^５及びＲ^６が片側炭素に置換されたシクロオレフィン単量体を用いることで、分子の対称性が崩れたためか溶媒揮発時の樹脂の拡散運動を促進し、それに伴い極性基のフィルム表面への配向を促すことから、極性基の局在化の観点から好ましい。

(In General Formula (A-2), R ⁵ independently represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkylsilyl group having an alkyl group having 1 to 5 carbon atoms. R ⁶ represents A carboxy group, a hydroxy group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and p represents an integer of 0 to 2. )
In the present invention, as represented by the general formula (A-2), the symmetry of the molecule is lost by using a cycloolefin monomer in which the substituents R ⁵ and R ⁶ are substituted on one side carbon. It is preferable from the viewpoint of localization of the polar group because it promotes the diffusion movement of the resin during the volatilization of the solvent and promotes the orientation of the polar group on the film surface.

R ⁵ is a hydrocarbon group having 1 to 3 carbon atoms, and R ⁶ is preferably a carboxy group, a hydroxy group, an alkoxycarbonyl group or an allyloxycarbonyl group, and particularly preferably an alkoxycarbonyl group or an allyloxycarbonyl group. It is also preferable from the viewpoint of ensuring solubility during film formation.

  Although the structure of general formula (A-1) and (A-2) in this application is shown concretely below, it is not limited by the following specific examples.

The cycloolefin-based resin is a polymer obtained by homopolymerization or copolymerization of a cycloolefin monomer having a norbornene skeleton and having a structure represented by the general formulas (A-1) and (A-2). Yes, for example, the following may be mentioned, (1) to (3) are preferred, and (3) is more preferred.
(1) Ring-opening polymer of cycloolefin monomer (2) Ring-opening copolymer of cycloolefin monomer and copolymerizable monomer (3) Ring-opening of (1) or (2) above ( Hydrogenated (co) polymer of (co) polymer (4) (co) polymer hydrogenated after cyclization of the ring-opened (co) polymer of (1) or (2) above by Friedel-Craft reaction (5) Saturated polymer of cycloolefin monomer and unsaturated double bond-containing compound (6) Addition type (co) polymer of cycloolefin monomer and hydrogenated (co) polymer (7) Alternate copolymer of cycloolefin monomer and methacrylate or acrylate As a preferred cycloolefin polymer according to the present invention, structures represented by the following general formula (B-1) and general formula (B-2) The thing which has a unit is also mentioned. Such cycloolefin-based resins include only the structural unit represented by the general formula (B-1), only the structural unit represented by the general formula (B-2), the general formula (B-1) and the general formula ( The copolymer containing each structural unit of B-2) may be sufficient.

  Preferably, it is a copolymer resin containing only the structure of the general formula (B-2) or the structural units of both the general formula (B-1) and the general formula (B-2). The obtained cycloolefin resin is preferable in that it has an excellent glass transition temperature and high transmittance.

（一般式（Ｂ−１）中、Ｘは、−ＣＨ＝ＣＨ−で表される基又は式：−ＣＨ_２ＣＨ_２−で表される基である。Ｒ^１〜Ｒ^４は、それぞれ独立に水素原子；ハロゲン原子；酸素、窒素、イオウ又はケイ素を含む連結基を有していてもよい置換又は非置換の炭素原子数１〜３０の炭化水素基；又は極性基を表す。ｐは、０〜２の自然数を表す。）

（一般式（Ｂ−２）中、Ｘは、−ＣＨ＝ＣＨ−で表される基又は式：−ＣＨ_２ＣＨ_２−で表される基である。Ｒ^５は、それぞれ独立に水素原子、炭素数１〜５の炭化水素基、又は炭素数１〜５のアルキル基を有するアルキルシリル基を表す。Ｒ^６は、カルボキシ基、ヒドロキシ基、アルコキシカルボニル基、アリロキシカルボニル基、アミノ基、アミド基、シアノ基、フッ素原子、塩素原子、臭素原子、又はヨウ素原子を表す。ｐは、０〜２の整数を表す。）
本明細書では、本願に係るシクロオレフィン系樹脂の製造方法等については、特開２００８−１０７５３４号公報の記載を援用するものとし、その説明を省略する。

(In General Formula (B-1), X is a group represented by —CH═CH— or a group represented by the formula: —CH ₂ CH ₂ —. R ^{1 to} R ⁴ are each independently A hydrogen atom, a halogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms which may have a linking group containing oxygen, nitrogen, sulfur or silicon; Represents a natural number of ~ 2.)

(In General Formula (B-2), X is a group represented by —CH═CH— or a group represented by the formula: —CH ₂ CH ₂ —. R ⁵ is independently a hydrogen atom, Represents a hydrocarbon group having 1 to 5 carbon atoms or an alkylsilyl group having an alkyl group having 1 to 5 carbon atoms, wherein R ⁶ represents a carboxy group, a hydroxy group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide; A group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and p represents an integer of 0 to 2.)
In this specification, about the manufacturing method of the cycloolefin resin which concerns on this application, description of Unexamined-Japanese-Patent No. 2008-107534 shall be used, and the description is abbreviate | omitted.

  The cycloolefin resin can be used alone or in combination of two or more.

The preferred molecular weight of the cycloolefin resin according to the present invention is 0.2 to ⁵ cm ³ / g, more preferably 0.3 to ³ cm ³ / g, and particularly preferably 0.4 to 1. a 5 cm ³ / g, number average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) (Mn) is 8,000 to 100,000, more preferably 10,000 to 80,000, particularly preferably from 12,000 to 50,000, a weight average The molecular weight (Mw) is preferably in the range of 20000 to 300,000, more preferably 30000 to 250,000, particularly preferably 40000 to 200000.

  The intrinsic viscosity [η] inh, number average molecular weight and weight average molecular weight are in the above ranges, so that the cycloolefin resin has heat resistance, water resistance, chemical resistance, mechanical properties, and the cycloolefin film of the present invention. The molding processability of is improved.

  The glass transition temperature (Tg) of the cycloolefin resin according to the present invention is usually 110 ° C. or higher, preferably 110 to 350 ° C., more preferably 120 to 250 ° C., and particularly preferably 120 to 220 ° C. The case where Tg is 110 ° C. or higher is preferred because deformation hardly occurs due to use under high temperature conditions or secondary processing such as coating or printing.

  On the other hand, when Tg is 350 ° C. or lower, it is possible to avoid the case where the molding process becomes difficult, and it is possible to suppress the possibility that the resin is deteriorated by heat during the molding process.

  In the cycloolefin resin, a specific hydrocarbon resin described in, for example, Japanese Patent Application Laid-Open No. 9-221577 and Japanese Patent Application Laid-Open No. 10-287732, or a known heat is used as long as the effects of the present invention are not impaired. Plastic resins, thermoplastic elastomers, rubbery polymers, organic fine particles, inorganic fine particles, etc. may be blended. Specific wavelength dispersing agents, sugar ester compounds, antioxidants, peeling accelerators, rubber particles, plasticizers, ultraviolet rays An additive such as an absorbent may be included.

  As the cycloolefin resin, commercially available products can be preferably used. Examples of commercially available products include trade names of ARTON (registered trademark) G, ARTON F, ARTON R, and ARTON RX from JSR Corporation. These are available on the market and can be used.

[2] Other additives The cycloolefin-based film of the present invention may contain a matting agent, a retardation increasing agent, a plasticizer, an antioxidant, a light stabilizer, an antistatic agent, a release agent, and the like. Details of the main additives are described below.

[2.1] Matting Agent The cycloolefin-based film of the present invention is provided with a matting agent to impart unevenness to the film surface during film formation, to ensure slipperiness, and to achieve a stable winding shape. contains.

  In addition, the matting agent can function in order to prevent the produced film from being scratched or having deteriorated transportability when handled.

  Examples of the matting agent include fine particles of an inorganic compound and fine particles of a resin. Examples of fine particles of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, silicic acid Examples thereof include magnesium and calcium phosphate. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable.

  The average primary particle size of the fine particles is preferably in the range of 5 to 400 nm, and more preferably in the range of 10 to 300 nm. These may be mainly contained as secondary aggregates having a particle size in the range of 0.05 to 0.3 μm. If the particles have an average particle size in the range of 80 to 400 nm, the primary particles are not aggregated. It is also preferable that it is contained.

  The content of these fine particles in the film is preferably in the range of 0.01 to 1% by mass, and particularly preferably in the range of 0.05 to 0.5% by mass.

  The fine particles of silicon dioxide are commercially available under the trade names of, for example, Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.). .

  Zirconium oxide fine particles are commercially available, for example, under the names of Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

  Examples of resin fine particles include silicone resin, fluororesin, and acrylic resin. Silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 145, 3120, and 240 (manufactured by Toshiba Silicone Co., Ltd.) Are commercially available and can be used.

  Among these, Aerosil 200V, Aerosil R972V, and Aerosil R812 are particularly preferably used because they have a large effect of reducing the friction coefficient while keeping the haze of the base film low.

  In the cycloolefin film of the present invention, the dynamic friction coefficient of at least one surface is preferably in the range of 0.2 to 1.0.

[2.2] Retardation increasing agent In the present application, the retardation increasing agent is a retardation value Rt in the thickness direction of a cycloolefin-based film containing 3 parts by mass of the compound with respect to 100 parts by mass of the cycloolefin-based resin. A compound having a function of (light wavelength 590 nm measurement) showing a value of 1.1 times or more as compared with a non-added cycloolefin film.

  The retardation increasing agent used in the present invention is not particularly limited. For example, a conventionally known disk having an aromatic ring described in paragraphs [0143] to [0179] of JP-A-2006-113239. -Like compounds (1,3,5-triazine compounds, etc.), rod-like compounds described in paragraphs [0106] to [0112] of JP-A-2006-113239, paragraphs [0118] to [0133] of JP-A-2012-214682 The described pyrimidine compounds and the like can be used.

[2.3] Plasticizer In the present invention, a polyester resin can be further used as the plasticizer. The polyester resin is obtained by polymerizing a dicarboxylic acid and a diol, and 70% or more of the dicarboxylic acid structural unit (the structural unit derived from the dicarboxylic acid) is derived from the aromatic dicarboxylic acid, and the diol structural unit (derived from the diol). 70% or more of the structural unit is derived from an aliphatic diol.

  The proportion of the structural unit derived from the aromatic dicarboxylic acid is 70% or more, preferably 80% or more, more preferably 90% or more.

  The proportion of the structural unit derived from the aliphatic diol is 70% or more, preferably 80% or more, and more preferably 90% or more. Two or more polyester resins may be used in combination.

  Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, naphthalenedicarboxylic acid such as 2,7-naphthalenedicarboxylic acid, and 4,4′-biphenyldicarboxylic acid. 3,4'-biphenyldicarboxylic acid and the like and ester-forming derivatives thereof.

  As the polyester resin, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid, and monocarboxylic acids such as benzoic acid, propionic acid, and butyric acid can be used without departing from the object of the present invention.

  Examples of the aliphatic diol include ethylene glycol, 1,3-propylene diol, 1,4-butanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, and the like, and ester-forming derivatives thereof.

  As the polyester resin, monoalcohols such as butyl alcohol, hexyl alcohol, and octyl alcohol, and polyhydric alcohols such as trimethylolpropane, glycerin, and pentaerythritol can be used as long as the object of the present invention is not impaired.

  A known esterification method or transesterification method can be applied to the production of the polyester resin. Examples of the polycondensation catalyst used in the production of the polyester resin include known antimony compounds such as antimony trioxide and antimony pentoxide, germanium compounds such as germanium oxide, titanium compounds such as titanium acetate, and aluminum compounds such as aluminum chloride. Although it can, it is not limited to these.

  Preferred polyester resins include polyethylene terephthalate resin, polyethylene terephthalate-isophthalate copolymer resin, polyethylene-1,4-cyclohexanedimethylene-terephthalate copolymer resin, polyethylene-2,6-naphthalene dicarboxylate resin, polyethylene-2, 6-naphthalene dicarboxylate-terephthalate copolymer resin, polyethylene-terephthalate-4,4'-biphenyldicarboxylate resin, poly-1,3-propylene-terephthalate resin, polybutylene terephthalate resin, polybutylene-2,6-naphthalene There are dicarboxylate resins and the like.

  More preferable polyester resins include polyethylene terephthalate resin, polyethylene terephthalate-isophthalate copolymer resin, polyethylene-1,4-cyclohexanedimethylene-terephthalate copolymer resin, polybutylene terephthalate resin, and polyethylene-2,6-naphthalene dicarboxylate. Resin.

The intrinsic viscosity of the polyester resin (phenol / 1,1,2,2-tetrachloroethane = value measured at 25 ° C. in a 60/40 mass ratio mixed solvent) is in the range of 0.7 to 2.0 cm ³ / g. Is more preferable, and it is in the range of 0.8 to 1.5 cm ³ / g. Since the molecular weight of the polyester resin is sufficiently high when the intrinsic viscosity is 0.7 cm ³ / g or more, a molded product comprising the polyester resin composition obtained by using the polyester resin has mechanical properties necessary as a molded product. At the same time, transparency is improved. When the intrinsic viscosity is 2.0 cm ³ / g or less, the moldability is good. As other plasticizers, compounds described in the general formulas (PEI) and (PEII) in paragraphs [0056] to [0080] of JP2013-97279A may be used.

[2.4] Ultraviolet Absorber The cycloolefin-based film of the present invention preferably contains an ultraviolet absorber in order to shield unnecessary ultraviolet rays irradiated to the polarizing plate and the liquid crystal display device.

  Examples of ultraviolet absorbers include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like, but less benzotriazole compounds Compounds are preferred. In addition, ultraviolet absorbers described in JP-A-10-182621 and JP-A-8-337574 and polymer ultraviolet absorbers described in JP-A-6-148430 are also preferably used.

  When the cycloolefin-based film of the present invention is used as a protective film for a polarizing plate in addition to the optical compensation film, the ultraviolet absorber has an ability to absorb ultraviolet rays having a wavelength of 370 nm or less from the viewpoint of preventing deterioration of a polarizer and liquid crystal. From the viewpoint of excellent display performance and liquid crystal display properties, it is preferable that the liquid crystal display device has a characteristic that absorbs less visible light having a wavelength of 400 nm or more.

  The addition amount of the ultraviolet absorber is preferably in the range of 0.1 to 5.0% by mass and more preferably in the range of 0.5 to 5.0% by mass with respect to the polymer composition. preferable.

  Benzotriazole-based UV absorbers useful in the present invention include, for example, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t -Butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-butyl Phenyl) -5-chlorobenzotriazole, 2- [2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl] benzotriazole, 2,2 -Methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2'-hydroxy-3) -T-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol, octyl-3 -[3-t-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-t-butyl-4-hydroxy-5- ( A mixture of 5-chloro-2H-benzotriazol-2-yl) phenyl] propionate can be mentioned, but is not limited thereto.

  As commercially available products, “TINUVIN 109”, “TINUVIN 171”, “TINUVIN 326”, “TINUVIN 328” (above, trade name, manufactured by BASF Japan Ltd.) are preferable. Can be used.

[2.5] Antioxidant Antioxidant plays a role of delaying or preventing the base film from decomposing due to, for example, halogen as a residual solvent in the base film or phosphoric acid as a phosphoric acid plasticizer. Therefore, it is preferable to make it contain in a film.

  As such an antioxidant, a hindered phenol compound is preferably used. For example, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di- -T-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3 -(3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino)- 1,3,5-triazine, 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octa Sil-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide) 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxy Benzyl) -isocyanurate and the like.

  In particular, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3 -(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] is preferred. Further, for example, hydrazine-based metal deactivators such as N, N′-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine and tris (2,4-di- A phosphorus processing stabilizer such as t-butylphenyl) phosphite may be used in combination.

[3] Method for Producing Cycloolefin Film The cycloolefin film of the present invention is preferably a film produced by a solution casting film forming method.

  The cycloolefin film of the present invention includes a step of preparing a dope containing at least a cycloolefin resin and an organic solvent (dope preparation step), and casting the dope onto a support (also referred to as a casting film). )), A step of evaporating the solvent from the web on the support (solvent evaporation step), a step of peeling the web from the support (peeling step), and drying the obtained film. Step (first drying step), step of stretching the film (stretching step), step of further drying the stretched film (second drying step), step of winding up the obtained cycloolefin-based film (winding step) It is preferable that it is manufactured by.

  The above process will be described with reference to the drawings.

  FIG. 1 is a diagram schematically showing an example of a dope preparation step, a casting step, a drying step, and a winding step of a solution casting film forming method preferable for the present invention.

  When the matting agent is used, the fine particle dispersion in which the solvent and the matting agent are dispersed by the disperser passes from the charging tank 41 through the filter 44 and is stocked in the stock tank 42. On the other hand, the cycloolefin resin as the main dope is dissolved in the dissolving pot 1 together with the solvent, and the matting agent stored in the stock pot 42 is added and mixed as appropriate to form the main dope. The obtained main dope is filtered from the filter 3 and the stock kettle 4 by the filter 6, the additive is added by the merge pipe 20, mixed by the mixer 21, and fed to the pressure die 30.

  On the other hand, an additive (for example, an ultraviolet absorber, a phase difference increasing agent, etc.) is dissolved in a solvent, and is passed from the additive charging vessel 10 through the filter 12 and stocked in the stock vessel 13. After that, the main dope is mixed by the merge pipe 20 and the mixer 21 through the conduit 15 through the filter 15.

  The main dope fed to the pressure die 30 is cast on a metal belt-like support 31 to form a web 32, and peeled at a peeling position 33 after predetermined drying to obtain a film. The peeled web 32 is dried until it reaches a predetermined residual solvent amount while passing through a number of conveying rollers in the first drying device 34, and then stretched in the longitudinal direction or the width direction by the stretching device 35. After the stretching, the film is dried while passing through the conveying roller 37 until it reaches a predetermined residual solvent amount by the second drying device 36, and is wound into a roll by the winding device 38.

  Hereinafter, each step will be described.

(1) Dope preparation step In an organic solvent mainly composed of a good solvent for the cycloolefin resin, the dope prepared by dissolving the cycloolefin resin, in some cases, a phase difference increasing agent, a matting agent or other compound in a dissolution vessel while stirring. Or a step of preparing a dope which is a main solution by mixing the phase difference increasing agent, matting agent or other compound solution with the cycloolefin resin solution.

  When the cycloolefin-based film of the present invention is produced by the solution casting method, the organic solvent useful for forming the dope is one that simultaneously dissolves the cycloolefin resin, the retardation increasing agent, and other compounds. preferable.

  The organic solvent used in the present invention is a manufactured cycloolefin-based film having an aromatic solvent in the range of 50 to 300 ppm, a halide solvent in the range of 300 to 800 ppm, and a non-aromatic solvent. It is used as a mixed organic solvent so that the solvent (excluding halide solvents) is contained in the range of 300 to 6000 ppm.

  As the organic solvent used, the following solvents are preferably used.

  The aromatic solvent is preferably toluene, xylene, styrene, benzene, or a mixed solvent thereof. Of these, toluene is preferred.

  Moreover, in a commercially available cycloolefin resin, toluene etc. may be added as a solvent for resin synthesis, and in that case, it is handled as an aromatic organic solvent according to the present invention.

  The halide solvent is preferably a chlorine solvent such as chloroform, dichloromethane, 1,2 dichloroethane. Of these, dichloromethane is preferred.

Non-aromatic solvents (excluding halide solvents) have a solubility parameter value (SP value) in the range of 15 to 25 ((MPa) ^1/2 ) and a surface tension value of 20 to 25 ( mN / m) must be selected from the solvent and is preferably selected from isopropanol, octane, acetone, ethyl formate, 1-butanol, ethyl acetate and cyclohexane.

  These solvents may be used alone or in combination of two or more.

  Also, alcohol solvents such as methanol, ethanol, n-butanol, 2-butanol; organic solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, dimethylformamide, dimethyl sulfoxide, dioxane, cyclohexanone, tetrahydrofuran, methyl ethyl ketone (MEK), diethyl ether Can be used as long as the effects of the present invention are not impaired.

Adding a non-aromatic solvent having a solubility parameter value (SP value) exceeding 25 ((MPa) ^1/2 ) to the solvent structure according to the present invention also improves adhesion and reduces display unevenness. This is a preferred embodiment from the viewpoint of the effect of reducing the charge of the cycloolefin-based resin and forming a uniform and excellent adhesive layer in the coating process.

  The organic solvent used in the present invention is preferably a mixed solvent of a good solvent and a poor solvent, and examples of the good solvent include dichloromethane as a halide solvent. The good solvent is preferably used in an amount of 55% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more based on the total amount of the solvent.

  The poor solvent is preferably selected from non-aromatic solvents, and the non-aromatic solvent is selected from acetone or ethyl acetate, which improves releasability and enables high-speed casting. From the viewpoint of making it. When the ratio of the non-aromatic solvent in the dope is increased, the web is gelled and peeling from the metal support is facilitated, which is preferable. From the viewpoint of improving the flatness of the resulting cycloolefin-based film, it is preferable to form a film using a dope having a non-aromatic solvent concentration in the range of 0.5 to 30% by mass.

  For dissolving a cycloolefin resin, in some cases a retardation increasing agent, and other compounds, a method carried out at normal pressure, a method carried out below the boiling point of the main solvent, a method carried out under pressure above the boiling point of the main solvent, -95544, Japanese Patent Laid-Open No. 9-95557, or Japanese Patent Laid-Open No. 9-95538, a method using a cooling dissolution method, a method performed at a high pressure described in Japanese Patent Laid-Open No. 11-21379, and the like. However, the method carried out at normal pressure is preferred.

  The concentration of the cycloolefin-based resin in the dope is preferably in the range of 10 to 40% by mass. After the compound is added to the dope during or after dissolution and dissolved and dispersed, it is filtered through a filter medium, defoamed, and sent to the next step with a liquid feed pump.

  For dope filtration, it is preferable to filter the dope with a filter medium having a collection particle diameter of 90%, for example, 10 to 100 times the average particle diameter of the fine particles, preferably with a main filter 3 having a leaf disk filter. .

  In the present invention, the filter medium used for filtration preferably has a small absolute filtration accuracy. However, if the absolute filtration accuracy is too small, the filter medium is likely to be clogged, and the filter medium must be frequently replaced. There is a problem of lowering productivity.

  For this reason, in the present invention, the filter medium used for cycloolefin resin dope preferably has an absolute filtration accuracy of 0.008 mm or less, more preferably in the range of 0.001 to 0.008 mm, and more preferably 0.003 to 0.00. A filter medium in the range of 006 mm is more preferable.

  There are no particular restrictions on the material of the filter medium, and normal filter media can be used. However, plastic fiber filter media such as polypropylene and Teflon (registered trademark), and metal filter media such as stainless steel fibers are used to remove fibers. This is preferable.

In the present invention, the dope flow rate during filtration is preferably 10 to 80 kg / (h · m ² ), more preferably 20 to 60 kg / (h · m ² ). Here, if the flow rate of the dope at the time of filtration is 10 kg / (h · m ² ) or more, it becomes efficient productivity, and the flow rate of the dope at the time of filtration is within 80 kg / (h · m ² ). If so, the pressure applied to the filter medium is appropriate, and the filter medium is not damaged, which is preferable.

  The filtration pressure is preferably 3500 kPa or less, more preferably 3000 kPa or less, and even more preferably 2500 kPa or less. The filtration pressure can be controlled by appropriately selecting the filtration flow rate and the filtration area.

  In many cases, the main dope may contain about 10 to 50% by mass of the recycled material.

  Recycled material is, for example, a product obtained by finely pulverizing a cycloolefin-based film, which is generated when a cycloolefin-based film is formed, with both sides of the film cut off, or by scratches, etc., exceeding the specified value of the film. A cycloolefin film raw material is used.

  Moreover, as a raw material of resin used for dope preparation, what pelletized cycloolefin resin and another compound previously can be used preferably.

(2) Casting step (2-1) Casting of dope An endless metal support 31 that feeds the dope to the pressurizing die 30 through a feed pump (for example, a pressurization type metering gear pump) and transfers it infinitely, For example, the dope is cast from a pressure die slit at a casting position on a metal support such as a stainless steel belt or a rotating metal drum.

  The metal support in the casting (casting) step preferably has a mirror-finished surface, and a stainless steel belt or a drum whose surface is plated with a casting is preferably used as the metal support. The cast width can be in the range of 1-4 m, preferably in the range of 1.3-3 m, more preferably in the range of 1.5-2.8 m. The surface temperature of the metal support in the casting step is set in the range of −50 ° C. to a temperature at which the solvent boils and does not foam, more preferably in the range of −30 to 0 ° C. A higher temperature is preferable because the web (the dope is cast on a casting support and the formed dope film is referred to as a web) can be dried quickly, but if the temperature is too high, the web foams, The flatness may deteriorate. A preferable support temperature is appropriately determined at 0 to 100 ° C, and more preferably 5 to 30 ° C. Alternatively, it is also a preferable method that the web is gelled by cooling and peeled from the drum in a state containing a large amount of residual solvent.

  The method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing warm air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short. When using warm air, considering the temperature drop of the web due to the latent heat of vaporization of the solvent, while using warm air above the boiling point of the solvent, there may be cases where wind at a temperature higher than the target temperature is used while preventing foaming. . In particular, it is preferable to perform drying efficiently by changing the temperature of the support and the temperature of the drying air during the period from casting to peeling.

  The temperature of the dope to be cast (cast) is preferably 20 ° C. to 35 ° C. from the viewpoint of uniformly dispersing the film flatness, drying properties, additives, and mat material.

  The die is preferably a pressure die that can adjust the slit shape of the die portion of the die and easily make the film thickness uniform. Examples of the pressure die include a coat hanger die and a T die, and any of them is preferably used. The surface of the metal support is a mirror surface. In order to increase the film forming speed, two or more pressure dies may be provided on the metal support, and the dope amount may be divided and laminated.

(2-2) Solvent evaporation process It is the process of heating a web on the support body for casting, and evaporating a solvent, It is a process of controlling the residual solvent amount at the time of peeling mentioned later.

  To evaporate the solvent, there are a method of blowing air from the web side, a method of transferring heat from the back side of the support, a method of transferring heat from the front and back by radiant heat, etc. Is preferable. A method of combining them is also preferably used. The web on the support after casting is preferably dried on the support in an atmosphere of 30 to 100 ° C. In order to maintain the atmosphere at 30 to 100 ° C., it is preferable to apply hot air at this temperature to the upper surface of the web or heat by means such as infrared rays.

  From the viewpoint of surface quality, moisture permeability, and peelability, it is preferable to peel the web from the support within 30 to 180 seconds.

(2-3) Peeling Step This is a step of peeling the web where the solvent has evaporated on the metal support at the peeling position. The peeled web is sent to the next process as a film.

  The temperature at the peeling position on the metal support is preferably in the range of 10 to 40 ° C, more preferably in the range of 11 to 30 ° C.

  In this invention, although the solvent in a web is evaporated in the said solvent evaporation process, it is preferable that the residual solvent amount of the web on the metal support body in the time of peeling shall be in the range of 15-100 mass%. The residual solvent amount is preferably controlled by the drying temperature and drying time in the solvent evaporation step.

  When the residual solvent amount is 15% by mass or more, the matting agent has no distribution in the thickness direction and is uniformly dispersed in the film in the drying process on the support. It is possible to easily suppress the deformation of the winding shape. Also, the drying time is not lengthened and productivity is improved.

  Further, if the amount of the residual solvent is within 100% by mass, the film has self-supporting properties, can avoid poor peeling of the film, and can maintain the mechanical strength of the web, so that the flatness at the time of peeling is improved, Generation of slippage and vertical stripes due to peeling tension can be suppressed.

  The residual solvent amount of the web or film is defined by the following formula (Z).

Formula (Z)
Residual solvent amount (%) = (mass before heat treatment of web or film−mass after heat treatment of web or film) / (mass after heat treatment of web or film) × 100
Note that the heat treatment for measuring the residual solvent amount represents performing heat treatment at 115 ° C. for 1 hour.

  The peeling tension when peeling the web from the metal support to form a film is usually in the range of 196 to 245 N / m. However, if wrinkles easily occur during peeling, the peeling tension is 190 N / m or less. It is preferable to do.

  In the present invention, the temperature at the peeling position on the metal support is preferably in the range of −50 to 40 ° C., more preferably in the range of 10 to 40 ° C., and in the range of 15 to 30 ° C. Is most preferred.

(3) Drying and stretching step The drying step can be divided into a preliminary drying step (first drying step) and a main drying step (second drying step).

(3-1) Pre-drying step The film obtained by peeling the web from the metal support is pre-dried by the first drying device 34. Preliminary drying of the film may be performed while the film is being transported by a number of rollers arranged above and below, or may be dried while being transported by fixing both ends of the film with clips like a tenter dryer. Good.

  The means for drying the web is not particularly limited and can be generally performed with hot air, infrared rays, a heating roller, microwaves, or the like, but it is preferably performed with hot air in terms of simplicity.

  The drying temperature in the web pre-drying step is preferably a glass transition point of the film of −5 ° C. or lower, and it is effective to perform heat treatment at a temperature of 30 ° C. or higher for 1 minute or longer and 30 minutes or shorter. Drying is carried out at a drying temperature in the range of 40 to 150 ° C, more preferably in the range of 50 to 100 ° C.

(3-2) Stretching process The cycloolefin-based film of the present invention is stretched under the residual solvent amount by the stretching device 35 to improve the flatness of the film or control the orientation of molecules in the film. Thus, desired phase difference values Ro and Rt can be obtained.

  In the method for producing a cycloolefin-based film of the present invention, in the step of stretching the film, the amount of residual solvent at the start of stretching is preferably 1% by mass or more and less than 15% by mass. More preferably, it exists in the range of 2-10 mass%.

  The cycloolefin-based film of the present invention is preferably stretched in the longitudinal direction (also referred to as MD direction and casting direction) and / or in the lateral direction (also referred to as TD direction), and at least in the lateral direction by a stretching device. It is preferable to produce the film by stretching it.

  The stretching operation may be performed in multiple stages. When biaxial stretching is performed, simultaneous biaxial stretching may be performed or may be performed stepwise. In this case, stepwise means that, for example, stretching in different stretching directions can be sequentially performed, stretching in the same direction is divided into multiple stages, and stretching in different directions is added to any one of the stages. Is also possible.

Thus, for example, the following stretching steps are possible:
-Stretch in the longitudinal direction-> Stretch in the width direction-> Stretch in the longitudinal direction-> Stretch in the longitudinal direction-Stretch in the width direction-> Stretch in the width direction-> Stretch in the longitudinal direction-> Stretch in the longitudinal direction Includes stretching in one direction and contracting the other while relaxing the tension.

  The cycloolefin-based film of the present invention has a glass transition temperature Tg of the film in the longitudinal direction and / or the width direction, preferably in the width direction so that the film thickness after stretching is in a desired range. It is preferable to stretch in a temperature range of (Tg + 5) to (Tg + 50) ° C. When stretched in the above temperature range, the retardation can be easily adjusted, and the stretching stress can be reduced, so that the haze is lowered. Moreover, generation | occurrence | production of a fracture | rupture is suppressed and the cycloolefin type film excellent in planarity and the coloring property of the film itself is obtained. The stretching temperature is preferably in the range of (Tg + 10) to (Tg + 40) ° C.

  In addition, the glass transition temperature Tg here is a midpoint glass transition temperature (Tmg) determined according to JIS K7121 (1987) using a commercially available differential scanning calorimeter and measuring at a heating rate of 20 ° C./min. It is. A specific method for measuring the glass transition temperature Tg of a cycloolefin-based film is measured using a differential scanning calorimeter DSC220 manufactured by Seiko Instruments Inc. according to JIS K7121 (1987).

  The cycloolefin-based film of the present invention preferably stretches the film at least in the width direction at a stretching ratio in the range of 5 to 40% with respect to the original width, and further in the longitudinal direction and the width direction of the film, More preferably, the film is stretched at a stretching ratio in the range of 5 to 40%. In particular, the stretching ratio is more preferably 10 to 30% with respect to the original width. Within the above range, in particular, when a retardation increasing agent is included, not only a desired retardation value can be obtained, but also the film can be thinned. The stretching ratio in the present invention refers to the ratio (%) of the length or width of the film after stretching to the length or width of the film before stretching.

  There is no particular limitation on the method of stretching in the longitudinal direction. For example, a method in which a difference in peripheral speed is applied to a plurality of rolls, and the roll peripheral speed difference is used to stretch in the longitudinal direction, the both ends of the web are fixed with clips and pins, and the interval between the clips and pins is increased in the traveling direction. And a method of stretching in the longitudinal direction or a method of stretching in the longitudinal and lateral directions at the same time in the longitudinal and lateral directions. Of course, these methods may be used in combination.

  In order to stretch in the width direction, for example, the entire drying process or a part of the process as shown in Japanese Patent Application Laid-Open No. 62-46625 is held in the width direction by holding the width ends of the web with clips or pins. A method of drying while drying (called a tenter method), among them, a tenter method using a clip and a pin tenter method using a pin are preferably used.

  From the viewpoint of improving the flatness of the film, it is preferable to stretch the film in the width direction at a stretching speed of 250 to 500% / min.

  If the stretching speed is 250% / min or more, the planarity is improved and the film can be processed at a high speed, which is preferable from the viewpoint of production aptitude, and if it is within 500% / min, the film is broken. Can be processed without any problem.

  A preferable stretching speed is in a range of 300 to 400% / min, and is effective at the time of stretching at a low magnification. The stretching speed is defined by the following formula 1.

Formula 1 Stretching speed (% / min) = [(d ₁ / d ₂ ) −1] × 100 (%) / t
(In Formula 1, d ₁ is the width dimension in the stretching direction of the cycloolefin-based film of the present invention after stretching, d ₂ is the width dimension in the stretching direction of the cycloolefin-based film before stretching, and t is (Time (min) required for stretching.)
The cycloolefin film of the present invention contains, for example, a retardation increasing agent, and can impart a desired retardation value by stretching. The in-plane retardation value Ro and the thickness direction retardation value Rt were measured using an automatic birefringence meter Axoscan (Axo Scan Mueller Matrix Polarimeter: manufactured by Axometrics) in an environment of 23 ° C. and 55% RH. A three-dimensional refractive index measurement is performed at a wavelength of 590 nm, and the refractive indexes nx, ny, and nz obtained can be calculated.

Formula _{(i): Ro = (n} x -n y) × d (nm)
Formula (ii): Rt = {(n _x + n _y ) / 2−n _z } × d (nm)
In [Equation (i) and Formula (ii), n _x represents a refractive index in the direction x in which the refractive index is maximized in the plane direction of the film. n _y, in-plane direction of the film, the refractive index in the direction y perpendicular to the direction x. _nz represents the refractive index in the thickness direction z of the film. d represents the thickness (nm) of the film. ]
In the stretching step, usually, after stretching, holding and relaxation are performed. That is, in this step, it is preferable to perform a stretching step for stretching the film, a holding step for holding the film in a stretched state, and a relaxation step for relaxing the film in the stretched direction in this order. In the holding step, the drawing at the drawing rate achieved in the drawing step is held at the drawing temperature in the drawing step. In the relaxation stage, the stretching in the stretching stage is held in the holding stage, and then the stretching is relaxed by releasing the tension for stretching. The relaxation step may be performed at a temperature lower than the stretching temperature in the stretching step.

(3-3) Main drying step In the main drying step, the stretched film is heated and dried by the second drying device 36.

  Especially in this invention, in order to adjust the amount of organic solvents to contain in the cycloolefin type film of this invention, it is preferable to adjust suitably the conditions of this drying process.

  When the film is heated with hot air or the like, a means for preventing the mixing of used hot air by installing a nozzle that can exhaust used hot air (air containing solvent or wet air) is also preferably used. The hot air temperature is more preferably in the range of 40 to 350 ° C. The drying time is preferably about 5 seconds to 60 minutes, more preferably 10 seconds to 30 minutes.

  Further, the heating and drying means is not limited to hot air, and for example, infrared rays, heating rollers, microwaves, and the like can be used. From the viewpoint of simplicity, it is preferable to dry with hot air or the like while transporting the film with the transport rollers 37 arranged in a staggered manner. The drying temperature is more preferably in the range of 40 to 350 ° C. in consideration of the residual solvent amount, the expansion / contraction rate in conveyance, and the like.

  In the drying step, it is preferable to dry the film until the residual solvent amount is generally 0.5% by mass or less. Among them, the residual halide solvent is preferably dried to 0.08% by mass or less.

(4) Winding step (4-1) Knurling processing It is preferable to provide a slitter after the predetermined heat treatment or cooling treatment and cut off the end portion before winding to obtain a good winding shape. Furthermore, it is preferable to knurling both ends of the width.

  The knurling process can be formed by pressing a heated embossing roller against the film width end. Fine embossing is formed on the embossing roller, and by pressing the embossing roller, unevenness can be formed on the film and the end can be made bulky.

  The height of the knurling at both ends of the width of the cycloolefin-based film of the present invention is preferably 4 to 20 μm and the width is 5 to 20 mm.

  In the present invention, the knurling process is preferably provided after the drying in the film forming step and before the winding.

(4-2) Winding step This is a step of winding as a film after the residual solvent amount in the film becomes 1% by mass or less, and the dimensional stability is preferably achieved by setting the residual solvent amount to 0.5% by mass or less. Can be obtained.

  As a winding method, a generally used method may be used, and there are a constant torque method, a constant tension method, a taper tension method, a program tension control method with a constant internal stress, and the like.

[4] Physical properties of cycloolefin film <Haze>
The cycloolefin-based film of the present invention preferably has a haze of less than 1%, more preferably less than 0.5%. By setting the haze to less than 1%, there is an advantage that the transparency of the film becomes higher and it becomes easier to use as a film for optical applications.

  The haze value is measured at 10 points at equal intervals in the width direction of the film with a haze meter (NDH2000, manufactured by Nippon Denshoku Industries Co., Ltd.) in an environment of 23 ° C. and 50% RH. The haze is calculated.

<Equilibrium moisture content>
In the cycloolefin-based film of the present invention, the equilibrium moisture content at 25 ° C. and a relative humidity of 60% is preferably 4% or less, and more preferably 3% or less. By setting the equilibrium moisture content to 4% or less, it is preferable to easily cope with a change in humidity and to hardly change the optical characteristics and dimensions.

  Equilibrium moisture content was determined by leaving the sample film in a room conditioned at 23 ° C. and 20% relative humidity for 4 hours or more and then leaving it in a room conditioned at 23 ° C. and 80% RH for 24 hours. Using a moisture meter (for example, CA-20, manufactured by Mitsubishi Chemical Analytech Co., Ltd.), moisture is dried and vaporized at a temperature of 150 ° C., and then quantified by the Karl Fischer method.

<Film length, width, film thickness>
The cycloolefin-based film of the present invention is preferably long, specifically, preferably has a length of about 100 to 10,000 m, and is wound into a roll. Moreover, it is preferable that the width | variety of the cycloolefin type film of this invention is 1 m or more, More preferably, it is 1.3 m or more, and it is especially preferable that it is 1.3-4 m.

  The film thickness of the stretched film is preferably in the range of 10 to 50 μm from the viewpoint of thinning the display device and productivity. If the film thickness is 10 μm or more, a certain level of film strength and retardation can be expressed. When the film thickness is 50 μm or less, the film has a desired retardation and can be applied to make the polarizing plate and the display device thinner. Preferably, the film thickness is in the range of 20 to 35 μm.

[5] Surface protective layer The cycloolefin-based film of the present invention can suppress the generation of scratches on the surface due to conveyance before processing the transparent conductive layer by forming the surface protective layer on at least one surface of the base film. The adhesiveness with the conductive layer can be improved, which is preferable.

  Even in this case, since the polar group of the cycloolefin polymer is localized on the film surface side, the cycloolefin film of the present invention exhibits strong adhesion with the surface protective layer.

  The surface protective layer preferably contains a curable resin, and examples thereof include a thermosetting resin and an active energy ray curable resin. However, an active energy ray curable resin can be preferably used because of easy molding.

[5.1] Thermosetting resin Thermosetting resin is not particularly limited, and specifically, epoxy resin, cyanate ester resin, phenol resin, bismaleimide-triazine resin, polyimide resin, acrylic resin, vinylbenzyl resin. And various other thermosetting resins.

[5.2] Active energy ray-curable resin The active energy ray-curable resin that can be suitably used in the present invention refers to a resin that is cured through a crosslinking reaction or the like by irradiation with active rays such as ultraviolet rays and electron beams. . As the active energy ray curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used. The active energy ray curable resin is cured by irradiation with an active ray such as an ultraviolet ray or an electron beam. A resin layer is formed. Typical examples of the active energy ray curable resin include an ultraviolet curable resin and an electron beam curable resin, and an ultraviolet curable resin that is cured by ultraviolet irradiation is preferable.

  Examples of the ultraviolet curable resin include an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable epoxy resin. be able to.

Examples of commercially available ultraviolet curable resins applicable in the present invention include, for example, Adekaoptomer KR / BY series: KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B ( As described above, manufactured by ADEKA Corporation); Koei Hard A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101,
M-102, T-102, D-102, NS-101, FT-102Q8, MAG-1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Co., Ltd.); Seika Beam PHC2210 (S ), PHC X-9 (K-3), PHC2213, DP-10, DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (above, Daiichi Seika Kogyo Co., Ltd. ); KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201,
UVECRYL 29202 (manufactured by Daicel UCB); RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC-5120, RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (manufactured by DIC Corporation); 340 clear (above, manufactured by China Paint Co., Ltd.); Sunrad H-601, RC-750, RC-700, RC-600,
RC-500, RC-611, RC-612 (above, Sanyo Chemical Industries, Ltd.); SP-1509, SP-1507 (above, Showa Polymer Co., Ltd.); RCC-15C (Grace Japan, Inc.) Alonix M-6100, M-8030, M-8060 (above, manufactured by Toagosei Co., Ltd.) and the like can be appropriately selected and used.

  Moreover, it is preferable to contain a photoinitiator in the range of 2-30 mass% with respect to an ultraviolet curable resin in order to accelerate | stimulate hardening of an ultraviolet curable resin. As the photopolymerization initiator, a group of double salts of onium salts that release a Lewis acid that initiates cationic polymerization by light irradiation is particularly preferable.

  As a method for producing the surface protective layer, a coating liquid for forming the surface protective layer is used, for example, coating is performed by a known wet coating method such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, or an inkjet method. be able to.

  The coating amount of the surface protective layer coating solution is suitably from 0.1 to 40 μm, preferably from 0.5 to 30 μm, as the wet layer thickness. The layer thickness is 0.1 to 30 μm, preferably 1 to 10 μm.

  As a method for curing the surface protective layer, after forming the surface protective layer, the surface protective layer is irradiated with active energy rays, preferably ultraviolet rays, and finally the surface protective layer is cured.

As the light source, any light source that generates ultraviolet rays can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. Although the irradiation conditions vary depending on each lamp, the irradiation amount of the active energy ray is preferably within a range of 5 to 350 mJ / cm ² , and particularly preferably within a range of 250 to 300 mJ / cm ² .

[6] Transparent conductive layer The transparent conductive layer used in the present application preferably has a resistance value of 0.01 or more and 150 Ω / □ or less, more preferably a resistance value of the transparent conductive layer is 0.1 or more and 100 or less. . When the resistance value of the transparent conductive layer is 0.1 or more, durability against keystroke is obtained, and when the resistance value is 150 or less, it is preferable from the viewpoint of conductivity. In addition, the transparent conductive layer used in the present application only needs to satisfy the above resistance value, but preferably contains a copper mesh. Copper is less likely to cause a migration phenomenon than other metals and has a viewpoint of suppressing disconnection during keystroke. Is preferable.

[6.1] Metal nanowire The metal nanowire is a conductive material having a metal material, a needle shape or a thread shape, and a diameter of nanometer. The metal nanowire may be linear or curved. If a transparent conductive layer composed of metal nanowires is used, the metal nanowires can be shaped like a mesh, so that a good electrical conduction path can be formed even with a small amount of metal nanowires. Can be obtained. Furthermore, when the metal nanowire has a mesh shape, a transparent conductive film having a high light transmittance can be obtained by forming openings in the mesh space.

  The ratio between the thickness d and the length L of the metal nanowire (aspect ratio: L / d) is preferably 10 to 100,000, more preferably 50 to 100,000, and particularly preferably 100. -10,000. Thus, if metal nanowire with a large aspect ratio is used, metal nanowire cross | intersects favorably and high electroconductivity can be expressed with a small amount of metal nanowire. As a result, a transparent conductive film having a high light transmittance can be obtained. In the present specification, the “thickness of the metal nanowire” means the diameter when the cross section of the metal nanowire is circular, and the short diameter when the cross section of the metal nanowire is elliptical. If it is square, it means the longest diagonal. The thickness and length of the metal nanowire can be confirmed by a scanning electron microscope or a transmission electron microscope.

  The thickness of the metal nanowire is preferably less than 500 nm, more preferably less than 200 nm, particularly preferably 10 nm to 100 nm, and most preferably 10 nm to 50 nm. If it is such a range, a transparent conductive layer with high light transmittance can be formed.

  The length of the metal nanowire is preferably 2.5 to 1000 μm, more preferably 10 to 500 μm, and particularly preferably 20 to 100 μm. If it is such a range, a highly conductive transparent conductive film can be obtained.

  Any appropriate metal can be used as the metal constituting the metal nanowire as long as it is a highly conductive metal. As a metal which comprises the said metal nanowire, silver, gold | metal | money, copper, nickel etc. are mentioned, for example. Moreover, you may use the material which performed the plating process (for example, gold plating process) to these metals. Among these, silver or copper is preferable from the viewpoint of conductivity.

  Arbitrary appropriate methods may be employ | adopted as a manufacturing method of the said metal nanowire. For example, a method of reducing silver nitrate in a solution, a method in which an applied voltage or current is applied to the precursor surface from the tip of the probe, a metal nanowire is drawn at the probe tip, and the metal nanowire is continuously formed. Can be mentioned. In the method of reducing silver nitrate in a solution, silver nanowires can be synthesized by liquid phase reduction of a silver salt such as silver nitrate in the presence of a polyol such as ethylene glycol and polyvinylpyrrolidone. Uniform sized silver nanowires are described in, for example, Xia, Y. et al. etal. , Chem. Mater. (2002), 14, 4736-4745, Xia, Y. et al. etal. , Nano letters (2003) 3 (7), 955-960, and mass production is possible.

  The said transparent conductive layer can be formed by coating the composition for transparent conductive layer formation containing the said metal nanowire on the cycloolefin type | system | group film of this invention. More specifically, after the dispersion liquid (composition for forming a transparent conductive layer) in which the metal nanowires are dispersed in a solvent is applied onto the transparent substrate, the coating layer is dried to obtain a transparent conductive layer. Can be formed.

  Examples of the solvent include water, alcohol solvents, ketone solvents, ether solvents, hydrocarbon solvents, aromatic solvents and the like. From the viewpoint of reducing the environmental load, it is preferable to use water.

  The dispersion concentration of the metal nanowires in the composition for forming a transparent conductive layer containing the metal nanowires is preferably 0.1 to 1% by mass. If it is such a range, the transparent conductive layer excellent in electroconductivity and light transmittance can be formed.

  The composition for transparent conductive layer formation containing the said metal nanowire may further contain arbitrary appropriate additives according to the objective. Examples of the additive include a corrosion inhibitor that prevents corrosion of metal nanowires, and a surfactant that prevents aggregation of metal nanowires. The kind, number, and amount of additives used can be appropriately set according to the purpose. Moreover, the said composition for transparent conductive layer formation may contain arbitrary appropriate binder resins as needed, as long as the effect of this invention is acquired.

  Arbitrary appropriate methods may be employ | adopted as a coating method of the composition for transparent conductive layer formation containing the said metal nanowire. Examples of the coating method include spray coating, bar coating, roll coating, die coating, inkjet coating, screen coating, dip coating, letterpress printing method, intaglio printing method, and gravure printing method. Any appropriate drying method (for example, natural drying, air drying, heat drying) can be adopted as a method for drying the coating layer. For example, in the case of heat drying, the drying temperature is typically 100 ° C. to 200 ° C., and the drying time is typically 1 to 10 minutes.

  When the transparent conductive layer includes metal nanowires, the thickness of the transparent conductive layer is preferably 0.01 μm to 10 μm, more preferably 0.05 μm to 3 μm, and particularly preferably 0.1 μm to 1 μm. is there. If it is such a range, the transparent conductive film which is excellent in electroconductivity and light transmittance can be obtained.

  When the said transparent conductive layer contains metal nanowire, the total light transmittance of the said transparent conductive layer becomes like this. Preferably it is 85% or more, More preferably, it is 90% or more, More preferably, it is 95% or more.

[6.2] Metal mesh The transparent conductive layer containing a metal mesh is formed by forming fine metal wires in a lattice pattern on the cycloolefin film of the present invention. Any appropriate metal can be used as the metal constituting the metal mesh as long as it is a highly conductive metal. As a metal which comprises the said metal mesh, silver, gold | metal | money, copper, nickel etc. are mentioned, for example. Moreover, you may use the material which performed the plating process (for example, gold plating process) to these metals. Among these, copper is preferable, and a migration phenomenon hardly occurs, and it is also preferable from the viewpoint of suppressing disconnection at the time of keystroke.
The transparent conductive layer containing a metal mesh can be formed by any appropriate method. For example, the transparent conductive layer is formed by applying a photosensitive composition containing silver salt (a composition for forming a transparent conductive layer) onto the laminate, and then performing an exposure process and a development process to form a fine metal wire in a predetermined pattern. It can obtain by forming. The transparent conductive layer can also be obtained by printing a paste containing metal fine particles (a composition for forming a transparent conductive layer) in a predetermined pattern. Details of such a transparent conductive layer and a method for forming the transparent conductive layer are described in, for example, Japanese Patent Application Laid-Open No. 2012-18634, and the description thereof is incorporated herein by reference. Moreover, as another example of the transparent conductive layer comprised from a metal mesh, and its formation method, the transparent conductive layer and its formation method of Unexamined-Japanese-Patent No. 2003-331654 are mentioned.
When the said transparent conductive layer contains a metal mesh, the thickness of the said transparent conductive layer becomes like this. Preferably it is 0.1-30 micrometers, More preferably, it is 0.1-9 micrometers, More preferably, it is 1-3 micrometers.
When the said transparent conductive layer contains a metal mesh, the transmittance | permeability of the said transparent conductive layer becomes like this. Preferably it is 80% or more, More preferably, it is 85% or more, More preferably, it is 90% or more.

[7] Other layers The cycloolefin-based film of the present invention (transparent conductive film) provided with a transparent conductive layer can be provided with any appropriate other layer as required. Examples of the other layers include a hard coat layer, an antistatic layer, an antiglare layer, an antireflection layer, and a color filter layer.

  Hereinafter, it describes about other than the said structural layer.

[7.1] Adhesive layer The adhesive layer has an adhesive property that enables the transparent conductive film to be attached to the transparent conductive films, the display element, the cover glass or the cover film. Is a constituent layer for forming a touch panel display device by bonding the transparent conductive film to the display device.

  The adhesive layer is not particularly limited, and for example, any of a dry laminating agent, a wet laminating agent, an adhesive, a heat seal agent, a hot melt agent, and the like is used. As the adhesive, for example, a polyester resin, a urethane resin, a polyvinyl acetate resin, an acrylic resin, a silicone resin, a nitrile rubber, or the like is used. The laminating method is not particularly limited, and for example, it is preferable to carry out the roll method continuously from the viewpoint of economy and productivity. Moreover, it is preferable that the thickness of an adhesion layer is the range of about 1-100 micrometers normally from viewpoints, such as an adhesion effect and a drying rate.

  The transparent conductive film may include a release sheet on the other surface.

  The release sheet only needs to be able to protect the adhesiveness of the adhesive layer. For example, an acrylic film or sheet, a polycarbonate film or sheet, a polyarylate film or sheet, a polyethylene naphthalate film or sheet, a polyethylene terephthalate film Or a plastic film or sheet such as a sheet, a fluorine film, a resin film or sheet kneaded with titanium oxide, silica, aluminum powder, copper powder, etc., or a metal such as aluminum is applied to the resin kneaded with these. A resin film or sheet subjected to surface processing such as vapor deposition is used.

  The thickness of the release sheet is not particularly limited, but is usually preferably in the range of 12 to 250 μm.

[8] Touch Panel Display Device The shape of the pattern of the transparent conductive layer on the touch panel is not particularly limited as long as it is a pattern that operates well as a touch panel (for example, a capacitive touch panel). Examples include patterns described in JP-A No. 2010-164938, JP-A No. 2008-310550, JP-A No. 2003-511799, and JP-A No. 2010-541109.

  FIG. 2 is a schematic cross-sectional view of a display device including an example of the configuration of the touch panel.

  As shown in FIG. 2, the touch panel is formed by laminating a transparent conductive film patterned on the x-axis and a transparent conductive film 101 patterned on the y-axis using an adhesive film 105, and a cover glass on the outermost surface. The touch panel display device can be manufactured by combining the touch panel with the liquid crystal display device 107.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "mass part" or "mass%" is represented.

Example 1
<Production of cycloolefin film>
(Synthesis of cycloolefin polymer 1)
Charge 100 parts of the exemplified compound 22 of the cycloolefin monomer (general formula A-2), 3.6 parts of 1-hexene, which is a molecular weight regulator, and 200 parts of toluene, into a nitrogen-substituted reaction vessel and heat to 80 ° C. did. To this, 0.17 part of a 1.5 mol / L toluene solution of triethylaluminum ((C ₂ H ₅ ) ₃ Al) as a polymerization catalyst and tungsten hexachloride (WCl ₆ ) modified with t-butanol and methanol. And 1.0 part of a WCl ₆ solution (concentration 0.05 mol / L) in which the molar ratio of t-butanol to methanol and tungsten was 0.35: 0.3: 1 was added, and 3 parts at 80 ° C. were added. A ring-opening polymerization reaction was performed by heating and stirring for a time to obtain a polymer solution. The polymerization conversion rate in this polymerization reaction was 98%.

4000 parts of the obtained polymer solution was put in an autoclave, 0.48 parts of RuHCl (CO) [P (C ₆ H ₅ ) ₃ ] ₃ was added to the polymer solution, the hydrogen gas pressure was 10 MPa, the reaction temperature. Hydrogenation reaction was performed by heating and stirring for 3 hours at 160 ° C.

  After cooling the obtained reaction solution, the hydrogen gas was released, and this reaction solution was poured into a large amount of methanol to separate and recover a solidified product. The recovered coagulated product was dried to obtain cycloolefin polymer 1.

<Preparation of cycloolefin-based (COP) film 101>
(Preparation of fine particle additive solution)
Fine particles (Aerosil R812: manufactured by Nippon Aerosil Co., Ltd., primary average particle size: 7 nm, apparent specific gravity 50 g / L) 4 parts by mass Dichloromethane 48 parts by mass Ethyl acetate 48 parts by mass The above was stirred and mixed with a dissolver for 50 minutes. Dispersion was performed.

  Further, the particles were dispersed by an attritor so that the secondary particles had a predetermined particle size. This was filtered through Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution.

  Next, a main dope 1 having the following composition was prepared. First, methylene chloride was added to the pressure dissolution tank at a flow rate of 400 kg / min and ethyl acetate at a flow rate of 20 kg / min. Three minutes after the start of the addition of the solvent, the cycloolefin polymer 1 was added to the pressurized dissolution tank with stirring at a flow rate of 200 kg / min. Next, 5 minutes after the start of solvent addition, the fine particle additive solution was added, and this was heated to 80 ° C. and completely dissolved while stirring. The heating temperature was raised from room temperature at 5 ° C./min, dissolved in 30 minutes, and then lowered at 3 ° C./min.

The dope viscosity was 10,000 CP and the water content was 0.50%. This was designated as Azumi Filter Paper No. The main dope 1 was prepared by using 244 (filtration accuracy 0.005 mm) and filtering at a filtration flow rate of 300 L / m ² · h and a filtration pressure of 1.0 × 10 ⁶ Pa.

<Composition of main dope 1>
Cycloolefin polymer 1 100 parts by weight Methylene chloride 200 parts by weight Ethyl acetate 10 parts by weight Particulate additive solution 3 parts by weight Next, using an endless belt casting apparatus, the dope was placed on a stainless steel belt support at a temperature of 33 ° C. and a width of 1500 mm. Were uniformly cast. The temperature of the stainless steel belt was controlled at 30 ° C.

  On the stainless steel belt support, the solvent was evaporated until the residual solvent amount in the cast (cast) film was 75%, and then peeled off from the stainless steel belt support with a peeling tension of 130 N / m.

  The peeled cycloolefin-based film was stretched by 20% in the width direction using a tenter while applying heat at 160 ° C. The residual solvent at the start of stretching was 15%. Next, drying was completed while the drying zone was conveyed by a number of rollers. The drying temperature was 130 ° C. and the transport tension was 100 N / m. After drying, the film was slit to a width of 1.5 m, a knurling process having a width of 10 mm and a height of 10 μm was applied to both ends of the film, and wound into a roll to obtain a cycloolefin film 101 having a dry film thickness of 45 μm.

[Quantification of solvent content]
The solvent content in the prepared cycloolefin-based film was quantified by headspace gas chromatography using the following apparatus.

Headspace device: HP7694 Head Space Sampler (manufactured by Hewlett-Packard Company)
Temperature conditions: transfer line 200 ° C, loop temperature 200 ° C
Sample amount: 0.8 g / 20 ml vial GC: HP5890 (manufactured by Hewlett-Packard Company)
MS: HP5971 (manufactured by Hewlett-Packard Company)
Column: HP-624 (30 m x inner diameter 0.25 mm)
Oven temperature: initial temperature 40 ° C. (holding time 3 minutes), heating rate 10 ° C./min, ultimate temperature 200 ° C. (holding time 5 minutes)
As a result of quantification, 150 ppm of toluene as an aromatic solvent, 500 ppm of dichloromethane as a halide solvent, and 3000 ppm of ethyl acetate as a non-aromatic solvent were detected in the cycloolefin film 101.

  In addition, toluene was brought in from the solvent for synthesis | combination of the used cycloolefin type resin.

[Measurement of solubility parameter value (SP value) and surface tension value]
In addition, the solubility parameter value (SP value) at 25 ° C. of the solvent is ethyl acetate: 18.6 (MPa) ^1/2 from the description of Polymer Hand Book (Second Edition) Chapter IV Solubility Parameter Values, and the surface tension value is As a result of measuring at 25 ° C. using DY700 manufactured by Kyowa Interface Science Co., Ltd., it was 24.0 (mN / m).

<Production of cycloolefin-based (COP) films 102 to 114>
In the production of cycloolefin-based (COP) film 101, the amount of cycloolefin-based resin synthesis solvent (toluene) used, the amount of dichloromethane and ethyl acetate added in main dope 1, and the amount of ethanol added as another solvent were adjusted. Then, cycloolefin films 102 to 114 were produced in the same manner except that the solvent contents shown in Table 1 were used.

<Production of cycloolefin-based (COP) films 115 to 119>
In the production of the cycloolefin-based (COP) film 101, the monomer exemplified compounds 14, 16, 17, 26, and 28 are used in place of the monomer exemplified compound 22 used in the cycloolefin-based polymer 1. Cycloolefin films 115 to 119 were prepared in the same manner except that cycloolefin polymers were prepared in the same manner.

≪Evaluation≫
(1) Keystroke durability test <Preparation of transparent conductive film>
<Preparation of transparent conductive film 101H>
Silver nanowires are Sun, B.M. Gates, B.B. Mayers, & Y. Xia, “Crystalline silver nanobe by soft solution processing”, Nano letters, (2002), 2 (2) 165-168, followed by a process using a polyol in the presence of polyvinyl pyrrolidone (PVP). It is a nanowire synthesized by dissolving silver sulfate and reducing it. That is, in the present invention, nanowires synthesized by the modified polyol method described in Cambrios Technologies Corporation US Provisional Application No. 60 / 815,627 were used.
A silver nanowire containing 0.5% w / v of a silver nanowire having a short axis diameter of about 70 nm to 80 nm and an aspect ratio of 100 or more synthesized by the above method as a metal nanowire forming a transparent conductive layer An aqueous dispersion composition (ClearOhmTM, Ink-A AQ, manufactured by Cambrios Technologies Corporation) was applied onto the cycloolefin-based film 101 using a slot die coater so that the film thickness was 1.5 μm after drying. After drying, a pressure treatment was performed at a pressure of 2000 kN / m ² to form a transparent conductive layer to obtain a transparent conductive film 101H.

<Preparation of transparent conductive films 102H to 119H>
The transparent conductive layer produced with the transparent conductive film 101H was formed with respect to the cycloolefin type films 102-119, respectively, and the transparent conductive films 102H-119H were produced.

<Production of Touch Panel Display Devices 101T to 119T>
A touch panel member 107 as shown in FIG. 2 was produced using the patterned transparent conductive films 101H to 119H described in JP-T 2010-541109.

  FIG. 2 shows that a transparent conductive film 101 having a transparent conductive layer 104 formed by using a cycloolefin-based film 103 having a surface protective layer 102 as a base material is laminated in two layers via an adhesive film 105, and a cover glass is formed on the outermost surface. A touch panel display device having a configuration in which a touch panel member 107 provided with 106 is bonded to a liquid crystal display device 108.

  Next, the 21.5-inch VAIOTap21 (SVT21219DJB) touch panel member that had been bonded in advance was peeled off, and the above-prepared touch panel member was bonded to manufacture touch panel display devices 101T to 119T.

(Keystroke test method)
In a variable air-conditioning room (AES-200 manufactured by Asahi Kagaku Co., Ltd.) controlled at 40 ° C. and 95% RH, the keystroke tester 202 type-950-2 (touch panel research) The input pen was pressed 15,000 times from the upper side of the cover glass side under the conditions of a keystroke speed of 2 Hz and a load of 150 g. Note that the pen tip material of the input pen is a glass board with a measuring board laid under the rubber, and placed on the glass substrate so that the conductive mesh is on the glass side. The experiment was conducted using an experimental apparatus that can slide repeatedly under conditions of 5 cm and 1 second reciprocation (5 cm reciprocates in 1 second). Note that the pen tip material of the input pen is polyacetal, and R is 0.8 mm.

(Evaluation of resistance change rate)
Using a touch panel tester 001-29-2 (manufactured by Touch Panel Laboratories), the resistance value between terminals of the touch panel display device before and after the keystroke test was measured, and the resistance value change rate was evaluated based on the following evaluation criteria. .

A: The rate of increase of the surface resistance value before and after the keying test shows a value of less than 0.1%. : The rate of increase of the surface resistance value before and after the keying test shows a value of 1% or more. ×: The surface resistance value after keying cannot be measured due to disconnection.

(2) Display unevenness The touch panel display device is left in an environment of 40 ° C. and 95% RH for 300 hours, then placed in a 40 ° C. and dry environment for 2 hours, and then in an environment of 23 ° C. and 55% RH for 24 hours. After lighting, the unevenness was observed from the front of the display panel. Display unevenness is evaluated as follows, and ◯ and Δ are regarded as practical levels.

◎: Display panel unevenness cannot be recognized ○: Display panel has some unevenness, but the boundary is unclear and unevenness is inconspicuous ×: Display panel has unevenness, and the uneven and unclear areas are clear A visual rating of ○ or higher is a practically acceptable level.

  The structure of the cycloolefin film and the evaluation results are shown in Table 1 above.

From Table 1, using a cycloolefin polymer having a polar group, an aromatic solvent, a halide solvent, a solubility parameter value (SP value), and a surface tension value are within the scope of the present invention. It can be seen that the cycloolefin-based films 101 to 108 and 115 to 119 of the present invention containing an aromatic solvent are superior in keystroke durability and display unevenness compared to the comparative example. In addition, it was found that display unevenness was further improved by using a solvent having an SP value exceeding 25 ((MPa) ^1/2 ) as the non-aromatic solvent in combination with the three solvents.

Example 2
<Preparation of cycloolefin-based (COP) film 201>
In the production of the cycloolefin film 101, a cycloolefin film 201 was produced in the same manner except that the main dope 1 was changed to the following main dope 2.

<Composition of main dope 2>
Cycloolefin-based polymer 1 100 parts by mass Methylene chloride 200 parts by mass Isopropanol 10 parts by mass Fine particle additive solution 3 parts by mass <Preparation of cycloolefin-based (COP) films 202 to 218>
In the production of the cycloolefin film 201, as shown in Table 2, as a solvent for synthesizing the cycloolefin resin, a resin using xylene and styrene in addition to toluene, which is an aromatic solvent, is used. In addition to using dichloromethane and 1.2 dichloroethane in addition to dichloromethane as the solvent, and using non-aromatic solvents in the same amount of the various solvents listed in Table 2, respectively, cycloolefin films 202 to 218 were formed. Produced.

  Using the produced cycloolefin-based films 201 to 218, (1) the keystroke durability test and (2) display unevenness of Example 1 were evaluated, and the results are shown in Table 2.

  From Table 2, the cycloolefin of the present invention containing an aromatic solvent, a halide solvent, and a non-aromatic solvent whose solubility parameter value (SP value) and surface tension value are within the scope of the present invention. It can be seen that the system films 201 to 211 reproduce Example 1 and are superior in keystroke durability and display unevenness to the comparative example.

DESCRIPTION OF SYMBOLS 1 Melting pot 3, 6, 12, 15 Filter 4, 13 Stock pot 2, 5, 11, 14 Liquid feed pump 8, 16 Conduit 10 Additive charging pot 20 Merge pipe 21 Mixer 30 Pressure die 31 Metal belt 32 Web 33 Peeling position 34 First drying device 35 Stretching device 36 Second drying device 37 Conveying roller 38 Winding device 41 Charging pot 42 Stock pot 43 Pump 101 Transparent conductive film 102 Surface protective layer 103 Cycloolefin film 104 Transparent conductive layer 105 Adhesive film 106 Cover glass 107 Touch panel member 108 Liquid crystal display device

Claims (5)

A cycloolefin film containing at least a cycloolefin polymer having a polar group, wherein an aromatic solvent is in the range of 50 to 300 ppm, a halide solvent is in the range of 300 to 800 ppm, and non- An aromatic solvent (excluding halide solvents) is contained within a range of 300 to 6000 ppm, and the solubility parameter value (SP value) of the non-aromatic solvent is 15 to 25 ((MPa) ^{1 / 2} ), and the surface tension value of the non-aromatic solvent is in the range of 20 to 25 (mN / m).   The cycloolefin film according to claim 1, wherein the content of the non-aromatic solvent is in a range of 800 to 3000 ppm. The cycloolefin-based film according to claim 1 or 2, wherein the cycloolefin-based polymer comprises a cycloolefin-based monomer having a structure represented by the general formula (A-2).

(In General Formula (A-2), R ⁵ independently represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkylsilyl group having an alkyl group having 1 to 5 carbon atoms. R ⁶ represents A carboxy group, a hydroxy group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and p represents an integer of 0 to 2. ) Furthermore, the non-aromatic solvent whose said solubility parameter value (SP value) is 25 ((MPa) < ^1/2 >) or more is contained, The any one of Claim 1 to 3 characterized by the above-mentioned. The cycloolefin-based film described in 1.   The non-aromatic solvent is selected from isopropanol, octane, acetone, ethyl formate, 1-butanol, ethyl acetate, and cyclohexane, according to any one of claims 1 to 4. Cycloolefin film.

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