TW202032582A - Transparent conductive thin film laminate in which the generation of curls and outgases can be suppressed - Google Patents

Abstract

An object of the present invention is to provide a transparent conductive thin film laminate in which the generation of curls and outgases is suppressed. To achieve the object, in both the first direction and the second direction orthogonal to the first direction, a base thin film having a small dimensional shrinkage rate and a MIT number of 500 or more is used. Moreover, the transparent conductive thin film laminate comprises: a conductive thin film including a resin thin film and a conductive film; and a carrier thin film including a base thin film containing a polyester resin, and an adhesive layer arranged on one side of the base thin film and temporarily attached to the conductive thin film via the adhesive layer in a detachable manner, wherein the carrier thin film is laminated on the side of the conductive thin film that is opposite to the conductive film, and the base thin film has a glass transition temperature (Tg) of 150 DEG C or higher, a dimensional shrinkage rate of 0.2% or lower at 145 DEG C in the first direction and the second direction orthogonal to the first direction, respectively, and a MIT number of 500 or more.

Description

Transparent conductive film laminate

The present invention relates to a transparent conductive thin film laminate.

The transparent conductive film used in touch panels and the like temporarily adheres the carrier film to form a laminate during actual use, and the laminate is used for manufacturing, transportation, storage, etc. However, in the case of the conventional transparent conductive thin film laminate, curling may occur in the heating step, and the production efficiency may become insufficient.

Previous prior art literature Patent literature Patent Document 1: Japanese Patent Application Publication No. 2017-190406

Problems to be solved by the invention

The present invention was made in order to solve the above-mentioned conventional problems, and its object is to provide a transparent conductive thin film laminate in which the generation of curl and outgas is suppressed. Means to solve the problem

The transparent conductive film laminate in the embodiment of the present invention includes: a conductive film including a resin film and a conductive film; and a carrier film having a base film including a polyester resin and a base film disposed on one side of the base film The adhesive layer is temporarily adhered to the conductive film in a peelable state through the adhesive layer; the carrier film is laminated on the side of the conductive film opposite to the conductive film; the glass transition temperature of the base film (Tg ) Is 150°C or higher, the dimensional shrinkage rate at 145°C is 0.2% or less in the first direction and the second direction orthogonal to the first direction, respectively, and the number of MITs is 500 times or more. In one embodiment, the polyester resin includes a polymer of (A) an acid component and (B) an alcohol component, and the (A) component includes (A1) a monocyclic aromatic polycarboxylic acid component, and (A2) A cyclic aromatic polycarboxylic acid component and (A3) a fluorene-based polycarboxylic acid component, and the (B) component includes (B1) an aliphatic polyol component and (B2) a fluorene-based polyol component; relative to the (A) component The content of the (A1) component is 5 mol% or more and less than 30 mol%, the content of the (A3) component is 5 mol% or more and 50 mol% or less; the (B2) component does not contain the actual amount of 9, 9-bis(aryl-hydroxy(poly)alkoxyaryl)fluorene component. In one embodiment, the above-mentioned (B2) component includes a first fluorene component in which two substituents having a hydroxyl group are introduced at the 9 position. In one embodiment, the component (B1) contains a 1,2-propanediol component, and the component (B2) contains a 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene component. In one embodiment, the above-mentioned (A3) component includes a second fluorene component in which two substituents having a carboxyl group and/or an ester group are introduced at the 9 position. In one embodiment, the component (A1) contains a terephthalic acid component, the component (A2) contains a 2,6-naphthalenedicarboxylic acid component, and the component (A3) contains 9,9-bis(carboxyethyl)fluorene ingredient. In one embodiment, the thickness of the carrier film is 15 μm to 100 μm. Invention effect

According to an embodiment of the present invention, in a transparent conductive film laminate having a transparent conductive film and a carrier film, by using a predetermined polyester-based resin, the dimensional shrinkage ratio is in the first direction and orthogonal to the first direction. A base film with a small number of MITs of 500 times or more in the second direction can provide a transparent conductive film laminate with suppressed curling and outgassing.

Hereinafter, preferred embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

A. Transparent conductive film laminate Fig. 1 is a schematic cross-sectional view of a transparent conductive thin film laminate according to an embodiment of the present invention. The transparent conductive film laminate 100 illustrated in the figure has a transparent conductive film 10 and a carrier film 20. The transparent conductive film 10 has a resin film 14 and a conductive layer 11 on the representative. The carrier film 20 has a base film 22 and an adhesive layer 21, and is temporarily adhered to the transparent conductive film 10 through the adhesive layer 21 in a peelable state. The carrier film may also have an anti-blocking hard coating (ABHC) layer 23 as required.

In the embodiment of the present invention, the glass transition temperature (Tg) of the base film 22 is 150°C or higher, preferably 155°C or higher. In addition, the dimensional shrinkage rate of the base film 22 at 145° C. is 0.2% or less in the first direction and the second direction orthogonal to the first direction. The first direction corresponds to, for example, the MD direction in the manufacturing method described later, and the second direction corresponds to, for example, the TD direction. In addition, the number of MITs of the base film 22 is 500 times or more. As long as the glass transition temperature (Tg) of the base film 22, the dimensional shrinkage rate at 145°, and the number of MITs fall within the aforementioned ranges, a transparent conductive film laminate with suppressed curling and outgassing can be obtained. In addition, the number of times of folding endurance of the base film 22 is preferably 100 times or more.

The thickness of the carrier film 20 is preferably 15 μm to 100 μm, more preferably 15 μm to 80 μm, and more preferably 15 μm to 60 μm. As long as the thickness of the carrier film is in the above-mentioned range, a transparent conductive film laminate with suppressed curl and outgassing can be obtained. In addition, the thickness of the carrier film refers to the total thickness when the base film, the adhesive layer and, if necessary, the anti-blocking hard coat (ABHC) layer is laminated.

B. Transparent conductive film The transparent conductive film 10 of the embodiment of the present invention includes a resin film 14 and a conductive layer 11. The conductive layer is typically formed on the viewing side surface of the resin film. The transparent conductive film may also have an index matching (IM) layer 12, a hard coat (HC) layer 13 and/or an anti-blocking hard coat (ABHC) layer 15 as required.

(Resin film) The resin film can be made of any appropriate resin. Examples of the resin constituting the resin film include cycloolefin resin (COP) and polyester resin. The details of the cycloolefin resin (COP) are described in, for example, JP 2016-107503 A. In this specification, the description of the publication is cited as a reference.

The thickness of the resin film is preferably 10 μm to 80 μm, more preferably 10 μm to 60 μm, and more preferably 10 μm to 40 μm.

(Conductive layer) The conductive layer represents a transparent conductive layer. The total light transmittance of the conductive layer is preferably 80% or more, more preferably 85% or more, and more preferably 90% or more.

The density of the conductive layer is preferably 1.0 g/cm ³ to 10.5 g/cm ³ , and more preferably 1.3 g/cm ³ to 8.0 g/cm ³ .

The surface resistance of the conductive layer should be 0.1Ω/□~1000Ω/□, more preferably 0.5Ω/□~500Ω/□, and more preferably 1Ω/□~250Ω/□.

As a representative example of the conductive layer, a conductive layer containing a metal oxide can be cited. Examples of metal oxides include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, and indium-zinc composite oxide. Among them, indium-tin composite oxide (ITO) is preferred.

The thickness of the conductive layer is preferably 0.01 μm to 0.06 μm, more preferably 0.01 μm to 0.045 μm. As long as it is in the above range, a conductive layer excellent in conductivity and light transmittance can be obtained.

The conductive layer can be formed by sputtering on the surface of the resin film.

(Index matching (IM) layer) The IM layer can be formed on one side of the conductive layer. Regarding the IM layer, a well-known structure in the industry can be adopted, so detailed description is omitted.

(Hard coating (HC) layer) The HC layer may be formed between the IM layer and the resin film. Regarding the HC layer, a structure well-known in the industry can be adopted, so detailed description is omitted.

(Anti-adhesive hard coating (ABHC) layer) The ABHC layer may be formed on the surface of the resin film on the opposite side to the HC layer. The details of the ABHC layer are described in, for example, JP 2016-107503 A. In this specification, the description of the publication is cited as a reference.

C. Carrier film The carrier film 20 includes an adhesive layer 21 and a base film 22. The carrier film 20 may have an anti-blocking hard coating (ABHC) layer 23 as required.

(Base film) The base film of the embodiment of the present invention is composed of a film containing a polyester resin. The polyester resin represents a polymer containing (A) an acid component and (B) an alcohol component. The (A) component contains (A1) a monocyclic aromatic polyvalent carboxylic acid component, (A2) a polycyclic aromatic polyvalent carboxylic acid component, and (A3) a fluorene-based polyvalent carboxylic acid component. The (B) component contains (B1) an aliphatic polyol component and (B2) a fluorene-based polyol component. Typically, with respect to the total amount of the (A) component, the content of the (A1) component is 5 mol% or more and less than 30 mol%, and the content of the (A3) component is 5 mol% or more and 50 mol% or less. The component (B2) represents the 9,9-bis(aryl-hydroxy(poly)alkoxyaryl)fluorene component without substantial amount.

The monocyclic aromatic polyvalent carboxylic acid component (A1) may contain a component having a plurality of substituents having a carboxyl group introduced into the benzene ring. As (A1) component, a terephthalic acid component and an isophthalic acid component are mentioned, for example. In the component (A1), terephthalic acid is preferably 50 mol% or more, and preferably 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol% or more, and more preferably 100 mol%. By using terephthalic acid as the main component, heat resistance can be improved.

The polycyclic aromatic polyvalent carboxylic acid component (A2) may contain a component having a plurality of substituents having a carboxyl group introduced into the naphthalene ring. In this specification, the component (A3) is not included in the component (A2). As the component (A2), for example, 2,6-naphthalenedicarboxylic acid component, 1,5-naphthalenedicarboxylic acid component, 1,6-naphthalenedicarboxylic acid component, 1,7-naphthalenedicarboxylic acid component, 1,8-Naphthalenedicarboxylic acid component. In the component (A2), the 2,6-naphthalenedicarboxylic acid component is preferably 50 mol% or more, and preferably 70 mol% or more, more preferably 80 mol% or more, more preferably 90 mol% or more, and more preferably 100 mol%. By using 2,6-naphthalenedicarboxylic acid as the main component, heat resistance can be improved.

The fluorene-based polycarboxylic acid component (A3) may include a component in which a plurality of substituents having carboxyl groups are introduced into fluorene. An example of the chemical formula of the fluorene-based polycarboxylic acid component is shown in the following chemical formula 1. (A3) The component may include, for example, a component in which two substituents having a carboxyl group and/or an ester group are introduced at the 9 position of fluorene. In Chemical Formula 1, R ¹ and R ² may adopt the same substituent. R ¹ and R ² can be, for example, carboxyalkyl (-(CH ₂ ) _n COOH). As the (A3) component, the 9,9-bis(carboxyethyl)fluorene component shown in the following chemical formula 2, etc. are mentioned, for example. In the component (A3), the 9,9-bis(carboxyethyl)fluorene component is preferably 50 mol% or more, and preferably 70 mol% or more, more preferably 80 mol% or more, preferably 90 mol% or more, and more preferably 100 mol%. By using 9,9-bis(carboxyethyl)fluorene as the main component, birefringence can be reduced, and as a result, a base film with a desired in-plane retardation can be obtained.

[化學式2]

[Chemical formula 1]

[Chemical formula 2]

The content of the (A1) component relative to the total amount of the acid component is preferably 5 mol% or more, preferably 8 mol% or more, and more preferably 10 mol% or more. If the content of the component (A1) is less than 5 mol%, the birefringence may increase. The content of (A1) component relative to the total amount of acid components is preferably less than 30 mol%, preferably 29 mol% or less, and more preferably 28 mol% or less. If the content rate of (A1) component is 30 mol% or more, heat resistance may become insufficient.

(A2) The content of the component relative to the total amount of acid components is preferably 25 mol% or more, preferably 30 mol% or more, and more preferably 35 mol% or more. If the content of the component (A2) is less than 25 mol%, heat resistance may become insufficient. (A2) The content of the component relative to the total amount of acid components is preferably 70 mol% or less, preferably 60 mol% or less, and more preferably 55 mol% or less. If the content of the component (A2) exceeds 70 mol%, the birefringence may increase.

The content of the (A3) component relative to the total amount of acid components is preferably 5 mol% or more, preferably 10 mol% or more, and more preferably 15 mol% or more. If the content of the component (A3) is less than 5 mol%, the birefringence may increase. The content of (A3) component relative to the total amount of acid components is preferably 50 mol% or less, preferably 45 mol% or less, and more preferably 40 mol% or less. If the content rate of the component (A3) exceeds 50 mol%, the heat resistance may become insufficient.

The molar ratio (A1)/(A2) of the component (A1) to the component (A2) is preferably 0.1 to 0.9, preferably 0.2 to 0.8, and more preferably 0.3 to 0.75. The molar ratio (A1)/(A3) of the component (A1) to the component (A3) is preferably 0.4 to 3, preferably 0.5 to 2.7, and more preferably 0.6 to 2.5. The molar ratio (A2)/(A3) of (A2) component to (A3) component is preferably 0.8~3, preferably 1~2.7, and more preferably 1.2~2.5.

The aliphatic polyol component (B1) may contain an alkanediol component with 2 to 4 carbon atoms. As the (B1) component, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4- Butylene glycol. (B1) Among the components, the 1,2-propanediol component is preferably 50 mol% or more, and preferably 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol% or more, and more preferably 100 mol%. By using 1,2-propanediol as the main component, it can increase the glass transition temperature compared to other aliphatic polyols.

The fluorene-based polyol component may include a component in which a plurality of substituents having hydroxyl groups are introduced into fluorene. An example of the chemical formula of the fluorene-based polyol component is shown in the following chemical formula 3. (B2) The component may include, for example, a component in which two substituents having a hydroxyl group are introduced at the 9 position of fluorene. In Chemical Formula 3, R ³ and R ⁴ may adopt the same substituent. R ³ and R ⁴ can be, for example, a hydroxyalkoxyaryl group. As the (B2) component, for example, 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene component, 9,9-bis[4-(2-hydroxyethoxy)-3 -Methylphenyl]fluorene component, 9,9-bis[4-(2-hydroxyethoxy)-3,5-dimethylphenyl]fluorene component, 9,9-bis[4-(2- Hydroxyethoxy)-3,5-diethylphenyl]fluorene component, etc. Among them, as the component (B2), the 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene component shown in the following chemical formula 4 is particularly preferable. (B2) Among the components, the 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene component is preferably 50mol% or more, preferably 70mol% or more, more preferably 80mol% or more, and 90mol% The above is preferable, and 100 mol% is more preferable. By using 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene as the main component, the heat resistance of the obtained base film can be improved, and the birefringence can be reduced (as a result, in-plane Phase difference). Especially in the component (B2), the 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene component is more preferably 70 mol% or more, and more preferably 80 mol% or more, and more preferably 90 mol% Above, 100 mol% is more preferable.

The component (B2) should preferably not contain substantial amounts of 9,9-bis(aryl-hydroxy(poly)alkoxyaryl)fluorene component. The 9,9-bis(aryl-hydroxy(poly)alkoxyaryl) fluorene component can be, for example, as shown in the following chemical formula 5, 9,9-bis[4-(2-hydroxyethoxy)-3- Phenylphenyl] fluorene component. If the 9,9-bis(aryl-hydroxy(poly)alkoxyaryl) fluorene component is included, the mechanical properties and/or moldability may become insufficient. Here, the "substantial amount" refers to the amount that can produce the effect of the 9,9-bis(aryl-hydroxy(poly)alkoxyaryl) fluorene component.

[化學式4]

[化學式5]

[Chemical formula 3]

[Chemical formula 4]

[Chemical formula 5]

The content of the component (B1) relative to the total amount of alcohol components is preferably 3 mol% or more, and preferably 5 mol% or more, and more preferably 8 mol% or more. If the content of the (B1) component is less than 3 mol%, the mechanical properties and/or moldability may become insufficient. (B1) The content of the component relative to the total amount of alcohol components is preferably 30 mol% or less, and is preferably 20 mol% or less, and more preferably 15 mol% or less. If the content of the component (B1) exceeds 30 mol%, the heat resistance may become insufficient.

(B2) The content of the component relative to the total amount of alcohol components is preferably 70 mol% or more, preferably 80 mol% or more, and more preferably 85 mol% or more. If the content of (B2) component is less than 70 mol%, heat resistance may become insufficient. (B2) The content of the component relative to the total amount of alcohol components is preferably 97 mol% or less, preferably 95 mol% or less, and more preferably 92 mol% or less. If the content of the component (B2) exceeds 97 mol%, mechanical properties and/or moldability may become insufficient.

The molar ratio (B2)/(B1) of (B1) component to (B2) component is preferably 4-30, 6-20, and 7-10 more preferably.

The details of the polyester resin are described in, for example, Japanese Patent Application Laid-Open No. 2018-168210. In this specification, the description of the publication is cited as a reference.

The thickness of the base film is preferably 10 μm to 80 μm, more preferably 10 μm to 60 μm, and more preferably 10 μm to 40 μm.

The elastic modulus of the base film should be 50MPa~350MPa at a stretching speed of 100mm/min. As long as the modulus of elasticity is in the above range, a base film excellent in transportability and handleability can be obtained. According to the embodiment of the present invention, the excellent elastic modulus (strength) and the above-mentioned excellent flexibility or bending resistance (flexibility) can be compatible. In addition, the elastic modulus is measured in accordance with JIS K 7127: 1999.

The tensile elongation of the base film should be 70%~200%. As long as the tensile elongation is in the above range, there is an advantage that it is not easy to break during transportation. In addition, the tensile elongation is measured in accordance with JIS K 6781.

(Method of manufacturing base film) The method for producing a base film according to an embodiment of the present invention includes: forming a film-forming material (resin composition) containing the polyester resin described in item A above into a film; and stretching the formed film.

The film forming material may contain other resins as described above in addition to the above-mentioned polyester-based resin, and may contain additives or a solvent. As the additive, any appropriate additive can be adopted according to the purpose. Specific examples of additives include reactive diluents, plasticizers, surfactants, fillers, antioxidants, anti-aging agents, ultraviolet absorbers, leveling agents, thixotropic agents, antistatic agents, and conductive materials. , Flame retardant. The number, type, combination, addition amount, etc. of additives can be appropriately set according to the purpose.

As a method of forming a thin film from a thin film forming material, any appropriate forming method can be adopted. Specific examples include compression molding, transfer molding, injection molding, extrusion molding, blow molding, powder molding, FRP molding, cast coating (for example, casting), and calendering. Forming method, hot pressing method, etc. It is preferably an extrusion molding method or a casting coating method. This is because the smoothness of the obtained film can be improved, and good optical uniformity can be obtained. The molding conditions can be appropriately set according to the composition and kind of the resin used, the desired characteristics of the base film, and the like.

The stretching method of the film is representatively biaxial stretching, more specifically, successive biaxial stretching or simultaneous biaxial stretching. This is because a base film with a small in-plane phase difference can be obtained. Sequential biaxial stretching or simultaneous biaxial stretching represents the use of a tenter stretching machine. Therefore, the extension direction of the film is representatively the length direction and the width direction of the film.

The stretching temperature changes depending on the desired in-plane retardation and thickness of the base film, the type of resin used, the thickness of the film used, the stretching ratio, and the like. Specifically, the stretching temperature relative to the glass transition temperature (Tg) of the film is preferably Tg+5℃~Tg+50℃, and more preferably Tg+10℃~Tg+40℃. By stretching at the temperature, a base film with appropriate characteristics can be obtained in the embodiment of the present invention.

The stretch magnification varies depending on the desired in-plane retardation and thickness of the base film, the type of resin used, the thickness of the film used, the stretching temperature, and the like. When biaxial stretching (for example, sequential biaxial stretching or simultaneous biaxial stretching) is used, the difference between the stretching magnification in the first direction (for example, the length direction) and the stretching magnification in the second direction (for example, the width direction) should be as great as possible Possibly small, more preferably substantially equal. With this configuration, a resin film with a small in-plane phase difference can be obtained. When biaxial stretching (for example, sequential biaxial stretching or simultaneous biaxial stretching) is used, the stretching magnification may be 1.1 times to 3.0 times in the first direction (for example, the length direction) and the second direction (for example, the width direction), respectively.

In the embodiment of the present invention, the extension speed is preferably 10%/sec or less, more preferably 7%/sec or less, more preferably 5%/sec or less, and particularly preferably 2.5%/sec or less. By stretching the film containing the specific polyester-based resin as described above at the aforementioned low stretching speed, a base film with a small in-plane phase difference can be obtained. The lower limit of the extension speed may be 1.2%/sec, for example. If the stretching speed is too small, productivity may become impractical. In addition, in the case of biaxial stretching (for example, sequential biaxial stretching or simultaneous biaxial stretching), in terms of the stretching speed in the first direction (for example, the length direction) and the stretching speed in the second direction (for example, the width direction), The difference should be as small as possible, and more preferably substantially equal. With this configuration, the in-plane retardation Re (550) of the base film can be reduced.

(Adhesive layer) As the adhesive layer, as long as it has transparency, it can be used without particular limitation. Specifically, for example, acrylic polymer, silicone polymer, polyester, polyurethane, polyamide, polyvinyl ether, vinyl acetate/vinyl chloride copolymer, modified Base polymers such as rubber-based polymers such as polyolefin, epoxy-based, fluorine-based, natural rubber, and synthetic rubber. In particular, it is preferable to use an acrylic adhesive from the viewpoint that it is excellent in optical transparency, exhibits appropriate adhesive properties such as wettability, cohesiveness, and adhesiveness, and is also excellent in weather resistance and heat resistance.

In the adhesive constituting the adhesive layer, a tackifier, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a silane coupling agent, etc. may be appropriately used as needed. The thickness of the adhesive layer is preferably 5 μm to 100 μm, more preferably 10 μm to 50 μm, and more preferably 15 μm to 35 μm.

(Anti-adhesive hard coating (ABHC) layer) Since it has the same structure as the ABHC layer in the transparent conductive film, detailed description is omitted. Example

Hereinafter, the present invention will be specifically described with examples, but the present invention is not limited by these examples. The measurement methods of each characteristic in the examples are as follows. In addition, unless otherwise specified, "parts" and "%" in the examples are based on weight.

(1) MIT test The MIT test is carried out in accordance with JIS P 8115. Specifically, the base films obtained in the examples and comparative examples were cut into a length of 15 cm and a width of 1.5 cm, and used as a measurement sample. Mount the test sample (load 1.0kgf, jig R: 0.38mm) on the MIT flexural fatigue testing machine BE-202 (manufactured by TESTER SANGYO CO,.LTD.), at a test speed of 90cpm and a bending angle of 90° With 500 times as the upper limit, the bending is repeated, and the number of bending times when the test specimen is broken is used as the test value. (2) Flexural test The 180° bending test was repeated 100 times on the base films obtained in the Examples and Comparative Examples, and the number of bending times when the sample was broken was used as the test value. (3) Size shrinkage rate The thermal shrinkage rates in the longitudinal direction (MD direction) and the width direction (TD direction) of the base films obtained in the examples and comparative examples were measured as follows. Specifically, the base film was cut to a width of 100 mm and a length of 100 mm (test piece), and cross marks were given to the four corners, and the central part of the cross marks was measured using a CNC three-dimensional measuring machine (LEGEX774 manufactured by Mitutoyo Corporation) Length (mm) before heating in the MD and TD directions at 4 points. Then, it was put into an oven and heat-treated (145°C, 60 minutes). After leaving to cool at room temperature for 1 hour, the heated length (mm) of the 4 corners and 4 points in the MD and TD directions was measured again with a CNC three-dimensional measuring machine, and the measured value was substituted into the following equation to obtain Thermal shrinkage in MD and TD directions. Heat shrinkage rate (%)=[[Length before heating (mm)-Length after heating (mm)]/Length before heating (mm)]×100 (4) Escape The base film obtained in the examples and comparative examples was cut into a width of 100mm and a length of 100mm (test piece), and an adhesive was applied to the surface to be bonded to the transparent conductive film and the other surface, and the adhesive surface was attached A test piece was obtained on one side of the alkali glass. The obtained test piece was put into the autoclave under the conditions of 50° C. and 0.5 atm. After taking out the sample 15 minutes later, it was marked as 0 if there were no bubbles by the naked eye, and × was recorded as the occurrence of bubbles. (5) Curl The transparent conductive layer film laminates obtained in the examples and comparative examples were cut into a size of 20 cm×20 cm. After heating at 145°C for 60 minutes with the ITO face up, it was left to cool at room temperature (23°C) for 1 hour. Then, the sample is placed on a horizontal surface with the ITO layer facing upward, and the height of the central part from the horizontal surface (curl value A) is measured. The heights of the four corners from the horizontal plane were measured, and the average value (curl value B) was calculated. The curl value A minus the curl value B (A-B) was calculated as the curl amount. When the curl value was in the range of 0 mm to 50 mm, it was recorded as ○, and the others were recorded as ×.

>Example 1> 1-1. Production of transparent conductive film An anti-adhesive hard coat (ABHC) layer is formed on one side of a polycyclic olefin film (trade name "ZEONOR (registered trademark)" manufactured by Zeon Corporation, Japan) with a thickness of 50μm and a glass transition temperature of 165°C, and the The surface on the opposite side of the ABHC layer forms a hard coat (HC) layer. An index matching (IM) layer is formed on the surface of the HC layer opposite to the resin film. ITO was sputtered on the surface of the IM layer on the side opposite to the HC layer to form a conductive layer, and a transparent conductive film (thickness 25 μm) was obtained.

1-2. Polymerization of polyester resin As the raw material of the monocyclic aromatic polycarboxylic acid component (A1), dimethyl terephthalate is used; as the raw material of the polycyclic aromatic polycarboxylic acid component (A2), dimethyl 2,6-naphthalene dicarboxylic acid is used Esters; 9,9-bis(methoxycarbonylethyl) fluorene is used as the raw material of the fluorene polycarboxylic acid component (A3); 1,2-propanediol is used as the raw material of the aliphatic polyol component (B1); fluorene The raw material of the polyol component (B2) used 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene. Put (A1) raw material 15 mol%, (A2) raw material 50 mol%, (A3) raw material 55 mol%, (B1) raw material 10 mol%, and (B2) raw material 90 mol% into a 30-liter stainless steel reaction vessel, and react After nitrogen replacement in the container, the raw materials were dissolved at 150°C. Next, manganese acetate tetrahydrate and calcium acetate monohydrate were introduced as transesterification catalysts, the temperature was gradually increased to 240°C over 4 hours, and the reaction was continued for 1 hour while maintaining the temperature at 240°C. It was confirmed that by-products were no longer distilled out and predetermined by-products were distilled out. Next, an aqueous solution of trimethyl phosphate and germanium dioxide is prepared and added. Then, the temperature increase and the pressure decrease were gradually started, and after 90 minutes, the temperature became 270° C. and 0.13 kPa. The polycondensation reaction proceeded in this state, and the reaction continued until the predetermined torque was reached. After reaching a predetermined torque, the inside of the reaction vessel was pressurized with nitrogen, the resin was extruded into a bundle in cooling water, and cut to obtain pellets of polyester resin. The glass transition temperature of the obtained polyester resin was 155°C.

1-3. Production of polyester resin film After vacuum drying the obtained polyester resin at 80°C for 5 hours, a uniaxial extruder (manufactured by Isuzu Kakoki Corporation, screw diameter 25mm, cylinder setting temperature: 270°C) and T-die (width 200mm) are used. , Setting temperature: 270℃), cooling roll (setting temperature: 120℃~130℃), and the film forming device of the coiler, to produce a polyester resin film with a thickness of 100μm.

1-4. Production of base film The polyester-based resin film obtained above was simultaneously biaxially stretched twice in the longitudinal direction and the width direction to obtain a base film.

1-5. Production of carrier film Through general solution polymerization, an acrylic polymer with a weight average molecular weight of 600,000 is obtained with butyl acrylate/acrylic acid = 100/6 (weight ratio). To 100 parts by weight of the acrylic polymer, 6 parts by weight of an epoxy-based crosslinking agent (trade name "TETRAD C (registered trademark)" manufactured by Mitsubishi Gas Chemical Corporation) was added to prepare an acrylic adhesive. The acrylic adhesive obtained in the aforementioned manner was coated on the release-treated surface of the release-treated PET film, and heated at 120° C. for 60 seconds to form an adhesive layer with a thickness of 20 μm. Next, the PET film was bonded to one side of the base film produced in 1-4. via the adhesive layer. Then, the release-treated PET film was peeled off, and an anti-blocking hard coat (ABHC) layer was formed on the side opposite to the adhesive layer to produce a carrier film (thickness 40 μm).

1-6. Production of transparent conductive film laminate The carrier film is temporarily bonded to the surface of the transparent conductive film on the side where the conductive film is not formed by the adhesive layer in a peelable state to form a transparent conductive film laminate. The obtained transparent conductive thin film laminate was used for the evaluation of (4) and (5) above. The results are shown in Table 1.

>Example 2> Except that the thickness of the transparent conductive film was 15 μm and the thickness of the carrier film was 25 μm, a transparent conductive film laminate was obtained in the same manner as in Example 1. The obtained transparent conductive thin film laminate was used for the evaluation of (4) and (5) above. The results are shown in Table 1.

>Example 3> Except for setting the thickness of the transparent conductive film to 40 μm and the thickness of the carrier film to 100 μm, in the same manner as in Example 1, a transparent conductive film laminate was obtained. The obtained transparent conductive thin film laminate was used for the evaluation of (4) and (5) above. The results are shown in Table 1.

>Example 4> The resin film uses the polyester resin obtained in 1-4, and the thickness of the transparent conductive film is set to 25 μm and the thickness of the carrier film is set to 40 μm, except that it is transparent in the same manner as in Example 1 Conductive thin film laminate. The obtained transparent conductive thin film laminate was used for the evaluation of (4) and (5) above. The results are shown in Table 1.

>Comparative Example 1> A transparent conductive film laminate was obtained in the same manner as in Example 1, except that polycarbonate (PC) was used as the carrier film. The obtained transparent conductive thin film laminate was used for the evaluation of (4) and (5) above. The results are shown in Table 1.

>Comparative Example 2> Except that the thickness of the transparent conductive film was 40 μm, the polyester resin was used for the carrier film, and the thickness of the carrier film was 110 μm, a transparent conductive film laminate was obtained in the same manner as in Example 1. The obtained transparent conductive thin film laminate was used for the evaluation of (4) and (5) above. The results are shown in Table 1.

>Comparative Example 3> A transparent conductive film laminate was obtained in the same manner as in Example 1 except that a polycycloolefin resin (COP) was used as the carrier film. The obtained transparent conductive thin film laminate was used for the evaluation of (4) and (5) above. The results are shown in Table 1.

[Table 1]

>Evaluation> It is clear from Table 1 that the transparent conductive film laminates of the examples of the present invention suppress the occurrence of outgassing and curling. It is estimated that this can be achieved by making the carrier film contain a specific polyester-based resin, the dimensional change rate of the polyester-based resin at 145°C for 1 hour heating is less than a predetermined value, and the number of MITs is 500 or more.

Industrial availability The transparent conductive film laminate of the present invention is suitable for use in touch panels.

10: Transparent conductive film 11: conductive layer 12: Index matching (IM) layer 13: Hard coating (HC) layer 14: Resin film 15: Anti-adhesive hard coating (ABHC) layer 20: carrier film 21: Adhesive layer 22: Base film 23: Anti-adhesion hard coating (ABHC) layer 100: Transparent conductive film laminate

Fig. 1 is a schematic cross-sectional view of a transparent conductive thin film laminate according to an embodiment of the present invention.

10: Transparent conductive film

11: conductive layer

12: Index matching (IM) layer

13: Hard coating (HC) layer

14: Resin film

15: Anti-adhesive hard coating (ABHC) layer

20: carrier film

21: Adhesive layer

22: Base film

23: Anti-adhesion hard coating (ABHC) layer

100: Transparent conductive film laminate

Claims (7)

A transparent conductive thin film laminate, including: A conductive film, which includes a resin film and a conductive film; and A carrier film comprising a base film containing a polyester resin and an adhesive layer disposed on one side of the base film, and is temporarily adhered to the conductive film in a peelable state through the adhesive layer; The carrier film is laminated on the side of the conductive film opposite to the conductive film; The glass transition temperature (Tg) of the base film is 150°C or higher, the dimensional shrinkage rate at 145°C is 0.2% or less in the first direction and the second direction orthogonal to the first direction, respectively, and the number of MITs is 500 Times or more. The transparent conductive film laminate of claim 1, wherein the polyester resin includes (A) a polymer of an acid component and (B) an alcohol component, This (A) component contains (A1) a monocyclic aromatic polycarboxylic acid component, (A2) a polycyclic aromatic polycarboxylic acid component, and (A3) a fluorene-based polycarboxylic acid component, The (B) component includes (B1) an aliphatic polyol component and (B2) a fluorene-based polyol component; Relative to the total amount of the (A) component, the content of the (A1) component is 5 mol% or more and less than 30 mol%, and the content of the (A3) component is 5 mol% or more and 50 mol% or less; This (B2) component does not contain a substantial amount of 9,9-bis(aryl-hydroxy(poly)alkoxyaryl)fluorene component. The transparent conductive thin film laminate according to claim 2, wherein the component (B2) includes a first fluorene component in which two substituents having a hydroxyl group are introduced at the 9 position. The transparent conductive film laminate of claim 2, wherein the aforementioned component (B1) contains a 1,2-propanediol component, and the aforementioned component (B2) contains 9,9-bis[4-(2-hydroxyethoxy)phenyl ] Fluorene ingredients. The transparent conductive thin film laminate of claim 2, wherein the component (A3) includes a second fluorene component in which two substituents having a carboxyl group and/or an ester group are introduced at the 9 position. The transparent conductive film laminate of claim 2, wherein the component (A1) contains terephthalic acid component, the component (A2) contains 2,6-naphthalene dicarboxylic acid component, and the component (A3) contains 9,9 -Bis (carboxyethyl) fluorene component. The transparent conductive film laminate according to any one of claims 1 to 6, wherein the thickness of the aforementioned carrier film is 15 μm to 100 μm.

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