JP2015072903A - Laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate capable of forming a transparent conductive film having excellent curl resistance and good pattern visibility in which a stuck transparent conductive film is not largely curled even during the heating step at a temperature range of 140 to 150°C.SOLUTION: There is provided the laminate which comprises: a carrier film for a transparent conductive film having an adhesive layer on at least one surface of a support; and a transparent conductive film having a transparent conductive layer and a transparent substrate, in which the in-plane heat shrinkage ratio S1 of the support when heated at 140°C for 90 minutes is 0.3 to 0.9% and the in-plane heat shrinkage ratio S2 of the transparent conductive film when heated at 140°C for 90 minutes is 0.3 to 0.6%.

Description

  The present invention relates to a laminate comprising a carrier film for a transparent conductive film and a transparent conductive film.

  In recent years, in a touch panel, a liquid crystal display panel, an organic EL panel, an electrochromic panel, an electronic paper element, and the like, demand for an element using a film substrate in which a transparent electrode is provided on a plastic film is increasing.

  As a material of the transparent electrode, currently, a thin film made of indium and tin oxide (ITO: Indium-Tin Oxide) is mainly used. In the transparent conductive film including the ITO thin film, in a processing process, a conveyance process, etc., For the purpose of preventing scratches and dirt, a surface protective film (carrier film) or the like is used by being bonded.

  By the way, as a surface protective film for the purpose of preventing curling of the transparent conductive film, for example, a surface protective film for a transparent conductive film that protects the surface opposite to the conductive thin film of the transparent conductive film, There has been proposed a surface protective film for a transparent conductive film, characterized in that the thermal shrinkage measured under specific conditions is 0.9% or less for both MD (flow direction) and TD (width direction) (for example, Patent Document 1).

Japanese Patent No. 4342775

  In recent years, in the field of touch panels and the like, there has been an increasing demand for thinner thicknesses, and accordingly, there has been a demand for thinner transparent conductive films themselves. As a general touch panel system, a resistive film system, a capacitive system, and the like can be given. In the case of the resistive film method, the durability of the pen is required due to the basic structure of the conductive method, so that it is difficult to reduce the thickness of the transparent conductive film. On the other hand, in the case of the capacitive method that has been widely used in touch panels in recent years, the transparent conductive film itself can be thinned because the position is detected using the change in capacitance. The demand from the market is strong.

  The thin transparent conductive film is inferior in stiffness and brittleness as compared to a thick transparent conductive film, and thus the processability and handleability in the touch panel manufacturing process are difficult. Therefore, as the thickness of the transparent conductive film is reduced, the surface protective film substrate is made thicker, and the total thickness of the laminate of the transparent conductive film and the surface protective film is reduced to that of the conventional thick transparent conductive film and thin. A method of supplementing the workability and handleability of the transparent conductive film can be considered by making the thickness approximately the same as the total thickness of the laminate when the surface protective film is employed. In other words, various processes such as crystallization of the ITO thin film, cutting of the transparent conductive film, resist printing, and etching are performed in a state where the surface protective film having a thick base material is laminated on the thin transparent conductive film. Therefore, it is considered that the workability and the handleability can be facilitated.

  However, when the transparent conductive film is thinned, the transparent conductive film itself is easily affected by the heat shrinkage behavior. For this reason, even if it is in the state where the surface protection film was laminated by the influence of the heating at the time of the etching at the time of the etching process at the time of the etching process in the above-mentioned touch panel manufacturing process, A new problem has arisen that deformation of the shape occurs. When the transparent conductive film having such irregularities is used in an actual product, the ITO pattern is easily seen when the display is turned on or off, resulting in a problem of pattern visibility.

  Furthermore, when the thickness of the transparent conductive film and the surface protective film is greatly different, the transparent conductive film in which the surface protective film is laminated due to the difference in thermal shrinkage rate of each film due to heating during the crystallization process of the ITO thin film described above The problem of curling has also arisen. If curling occurs in the transparent conductive film, it may cause problems such as being unable to float and suck with air or passing through the gate between processes when transporting a laminate having the transparent conductive film. It becomes difficult to carry out stable and continuous production.

  In the above-mentioned Patent Document 1, although the curl resistance of the transparent conductive film is a problem, the above-mentioned problem accompanying the thinning of the transparent conductive film and the heat shrinkage of the transparent conductive film as the adherend are described. The rate was not taken into account and was not sufficient to solve the problems of the present invention.

  The present invention solves the above-mentioned conventional problems. For example, even in a heating step of about 140 to 150 ° C., the attached transparent conductive film does not curl greatly, and has excellent curling resistance. It is an object to provide a laminated body. Moreover, an object of this invention is to provide the laminated body which can form the transparent conductive film which has favorable pattern visibility in addition to the said curl resistance.

  The inventors of the present invention have intensively studied to achieve the above object, and as a result, the transparent conductive film carrier having a specific in-plane heat shrinkage rate with respect to the transparent conductive film having a specific in-plane heat shrinkage rate. The inventors have found that the above object can be achieved by applying a film, and have completed the present invention.

That is, the present invention includes a carrier film for a transparent conductive film having an adhesive layer on at least one surface of a support, and a transparent conductive film having a transparent conductive layer and a transparent substrate,
In-plane heating shrinkage S1 when heated at 140 ° C. for 90 minutes of the support is 0.3 to 0.9%,
An in-plane heating shrinkage ratio S2 of the transparent conductive film when heated at 140 ° C. for 90 minutes is from 0.3 to 0.6%.

  The thickness of the support is preferably more than 70 μm and not more than 200 μm.

When the support is heated at 140 ° C. for 90 minutes, the heat shrinkage S1 _{md in the} longitudinal direction is preferably 0.9% or less, and the heat shrinkage S1 _{td in the} width direction is 0.6% or less. It is preferable.

  The support is preferably a polyester resin film.

  The pressure-sensitive adhesive layer is preferably formed from a pressure-sensitive adhesive composition containing a base polymer and a crosslinking agent.

  In the laminate of the present invention, the carrier film for a transparent conductive film including a support having a specific in-plane heat shrinkage rate is attached to the transparent conductive film having a specific in-plane heat shrinkage rate. The curl of the subsequent transparent conductive film can be easily conveyed without being extremely uneven. Moreover, when the transparent conductive film on the laminated body of this invention is processed, the obtained transparent conductive film can exhibit favorable pattern visibility.

It is a schematic diagram which shows the cross section of the carrier film for transparent conductive films used for this invention. It is a schematic diagram which shows the cross section of the laminated body of this invention.

The laminate of the present invention includes a carrier film for a transparent conductive film having an adhesive layer on at least one side of a support, and a transparent conductive film having a transparent conductive layer and a transparent substrate,
In-plane heating shrinkage S1 when heated at 140 ° C. for 90 minutes of the support is 0.3 to 0.9%,
The in-plane heating shrinkage S2 of the transparent conductive film is 0.3 to 0.6%.

1. Carrier film for transparent conductive film The carrier film for transparent conductive film used in the present invention (hereinafter sometimes simply referred to as “carrier film”) has an adhesive layer on at least one side of the support, The in-plane heat shrinkage S1 when heated at 140 ° C. for 90 minutes is 0.3 to 0.9%.

  The carrier film for transparent conductive film is used for a transparent conductive film having a transparent substrate and a transparent conductive layer, and in particular, has a transparent conductive layer and a transparent substrate, and is 90 minutes at 140 ° C. It is used for a transparent conductive film having an in-plane heat shrinkage ratio S2 of 0.3 to 0.6% when heated. And the adhesive of the carrier film for transparent conductive films on the transparent base material surface (the functional layer in the case where the transparent base material surface further has a functional layer) opposite to the transparent conductive layer of the transparent conductive film Use by laminating layers.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. However, the present invention is not limited to the embodiment of FIGS.

  The carrier film 3 for transparent conductive film used in the present invention has the pressure-sensitive adhesive layer 1 on at least one side of the support 2, and the in-plane heat shrinkage ratio S1 when the support 2 is heated at 140 ° C. for 90 minutes. 0.3 to 0.9%. Further, as shown in FIG. 2, the carrier film 3 used in the present invention has a transparent conductive layer 4 and a transparent substrate 5, and has an in-plane heat shrinkage ratio S2 of 0. when heated at 140 ° C. for 90 minutes. The adhesive layer 1 of the carrier film for transparent conductive film is laminated on the transparent conductive film 6, which is 3 to 0.6%, on the surface of the transparent substrate 5 opposite to the surface in contact with the transparent conductive layer 4. The adhesive side of is attached.

(1) Support The support 2 constituting the carrier film for transparent conductive film used in the present invention has an in-plane heat shrinkage ratio S1 of 0.3 to 0.9% when heated at 140 ° C. for 90 minutes. If it is a thing, it will not specifically limit. Here, the in-plane heat shrinkage rate of the support in the present invention refers to the shrinkage rate when measured in the state of a carrier film in which an adhesive is laminated on the support. This is because the heat shrinkage rate of the carrier film can be regarded as the heat shrinkage rate of the support because the pressure-sensitive adhesive layer has little influence on the heat shrinkage rate. The method for measuring the in-plane heat shrinkage rate is as follows.

<In-plane heating shrinkage>
The heat shrinkage S1 _{md in} the longitudinal direction (MD direction) and the heat shrinkage S1 _td in the width direction (TD direction) of the support are calculated as follows. Specifically, a carrier film composed of an adhesive layer and a support is cut into a size of 100 mm in width and 100 mm in length (test piece), and 80 mm in length in each of the MD and TD directions on the support side. The straight line is marked with a cross and the length of the mark in the MD and TD directions (mm) is measured using the Olympus digital small measuring microscope STM5.
(Measured by Olympus Optical Co., Ltd.) Thereafter, the test piece is placed with the pressure-sensitive adhesive layer facing upward, and heat treatment (140 ° C., 90 minutes) is performed. After allowing to cool for 1 hr at room temperature, the lengths of the marks in the MD direction and the TD direction are measured again, and the measured shrinkage rates in the MD direction and the TD direction are obtained by substituting the measured values into the following formulas.
Heat shrinkage S (%) = [[length of mark before heating (mm) −length of mark after heating (mm)] / length of mark before heating (mm)] × 100
The sum of the heat shrinkage rate S1 _md in the MD direction and the heat shrinkage rate S1 _{td in the} TD direction is defined as the in-plane heat shrinkage rate S1 (%) of the support.

  The in-plane heat shrinkage ratio S1 of the support is preferably 0.4 to 0.7%. In the present invention, it is preferable to set the in-plane heat shrinkage ratio S1 of the support within the above range because the curl of the transparent conductive film can be set within the optimum range.

The MD heat shrinkage S1 _md of the support is preferably 0.9% or less, more preferably 0.8% or less, still more preferably 0.6% or less, and It is particularly preferable that it is 5% or less. Although the lower limit of S1 _md of the support is not particularly limited, it is preferably 0% or more, more preferably 0.1% or more, and further preferably 0.2% or more. By making S1 _md of the support within the above range, shrinkage of the laminate during the etching treatment can be suppressed, and the pattern visibility of the transparent conductive film on the laminate of the present invention is improved, which is preferable.

The heat shrinkage ratio S1 _{td in} the TD direction of the support is preferably 0.6% or less, more preferably −0.2 to 0.4%, and 0.05 to 0.4%. Is more preferable, 0.05 to 0.30% is further preferable, and 0.10 to 0.30% is particularly preferable. For curl resistance, S1 _md of the support can be kept relatively low by maintaining S1 _td at the contraction level (that is, S1 _td is on the plus side). As a result, compared with a carrier film having a high S1 _md , it is possible to stably achieve both curl resistance and pattern visibility.

  As the support, for example, a paper-based support such as paper; a fiber-based support such as cloth, nonwoven fabric, and net (the raw material is not particularly limited; for example, Manila hemp, rayon, polyester, pulp fiber, etc. Metal support such as metal foil and metal plate; plastic support such as plastic film and sheet; rubber support such as rubber sheet; foam such as foam sheet, and these An appropriate thin leaf body such as a laminate (for example, a laminate of a plastic support and another support or a laminate of plastic films (or sheets)) can be used. A plastic support is preferable from the viewpoint of satisfaction.

  As a raw material in the plastic film or sheet, for example, α-olefin such as polyethylene (PE), polypropylene (PP), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA) is used as a monomer component. Olefin resins; Polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT); Polyvinyl chloride (PVC); Vinyl acetate resins; Polyphenylene sulfide (PPS); Polyamide (nylon) ), Amide resins such as wholly aromatic polyamide (aramid); polyimide resins; polyether ether ketone (PEEK) and the like. These materials can be used alone or in combination of two or more. Among these, since the polyester-based resin has toughness, workability, transparency, and the like, use of the polyester-based resin as a carrier film support improves workability / inspection, and is a more preferable embodiment. It becomes.

  The polyester resin is not particularly limited as long as it can be formed into a sheet shape or a film shape, and examples thereof include polyester films such as polyethylene terephthalate (PET), polyethylene naphthalate, and polybutylene terephthalate. . These polyester resins may be used alone (homopolymer), or two or more kinds may be mixed and polymerized (copolymers, etc.). Among these, polyethylene terephthalate is preferably used. By using polyethylene terephthalate, it becomes a carrier film excellent in toughness, workability, and transparency, and workability is improved, which is a preferred embodiment.

When the support used in the present invention is a resin film, the heat shrinkage rate of the resin film original fabric (resin film prior to heat treatment etc. before laminating the pressure-sensitive adhesive layer) forming the resin film is particularly limited. but are not, in particular as a resin raw film _{material, S md} is 1.2% or less, _and, it is preferable to use a polyester resin _{film S td} is -0.15～0.6%, It is more preferable to use a polyester-based resin film having an S _md of 0.9% or less and an S _{td of 0} to 0.6, an S _md of 0.8% or less, and an S _td of It is more preferable to use a polyester-based resin film that is 0.1 to 0.5. More preferably, the polyethylene terephthalate film is S _md or S _td .

  The thickness of the support is preferably more than 70 μm and not more than 200 μm, more preferably 90 to 150 μm, and still more preferably 100 to 130 μm. When the thickness of the support is within the above range, the layer thickness of the laminate can be maintained by applying it to a transparent conductive film that tends to be thin. Therefore, it is useful in that it has excellent transportability in a processing step, a transport step, and the like, and it is possible to prevent a problem of curling during heating such as a crystallization process or an etching process.

  In addition, the support may include a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, release with a silica powder, antifouling treatment, acid treatment, alkali treatment, primer, if necessary. Anti-adhesive treatment such as treatment, corona treatment, plasma treatment, and ultraviolet treatment, coating type, kneading type, and vapor deposition type can also be performed.

  In addition, in order to improve the adhesiveness between an adhesive layer and a support body, you may perform a corona treatment etc. on the surface of a support body. Moreover, you may perform a back surface process to a support body.

(2) Adhesive layer It is preferable that the adhesive layer in this invention is formed from the adhesive composition containing a base polymer and a crosslinking agent. The pressure-sensitive adhesive composition can be an acrylic, synthetic rubber-based, rubber-based, or silicone-based pressure-sensitive adhesive, but from the viewpoint of transparency, heat resistance, etc., a (meth) acrylic polymer is a base polymer. An acrylic pressure-sensitive adhesive is preferred.

  The (meth) acrylic polymer serving as the base polymer of the acrylic pressure-sensitive adhesive is preferably obtained by polymerizing a monomer component containing a (meth) acrylic acid ester having an alkyl group having 2 to 14 carbon atoms. Use of the (meth) acrylic acid ester is useful from the viewpoint of ease of handling.

  Examples of the (meth) acrylic acid ester having an alkyl group having 2 to 14 carbon atoms include ethyl (meth) acrylate, n-butyl (meth) acrylate (BA), t-butyl (meth) acrylate, isobutyl ( (Meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate (2EHA), n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, and the like can be mentioned. Or mix two or more To be able to use. Among these, (meth) acrylic acid ester having an alkyl group having 4 to 14 carbon atoms is more preferable, and n-butyl (meth) acrylate (BA) and 2-ethylhexyl (meth) acrylate (2EHA) are more preferable. Preferably, n-butyl (meth) acrylate (BA) is more preferably used as the main monomer. Here, the main monomer is 50% by weight or more, more preferably 60% by weight, based on the total amount of “(meth) acrylic acid ester having an alkyl group having 2 to 14 carbon atoms” contained in the monomer component. Or more, more preferably 80% by weight or more, and particularly preferably 100% by weight.

  The amount of the (meth) acrylic monomer having an alkyl group having 2 to 14 carbon atoms is preferably 55% by weight or more, more preferably 60 to 100% by weight, and particularly preferably 60 to 98% by weight in the monomer component. preferable.

  The monomer component may contain other polymerizable monomer other than (meth) acrylic acid ester having an alkyl group having 2 to 14 carbon atoms. As said other polymerizable monomer, the glass transition point of a (meth) acrylic-type polymer, the polymerizable monomer for adjusting peelability, etc. can be used in the range which does not impair the effect of this invention. These monomers may be used alone or in combination. However, the blending amount of the other polymerizable monomer is preferably 45% by weight or less, more preferably 0 to 40% by weight in the monomer component. preferable.

  Examples of the other polymerizable monomers include, for example, components for improving cohesion and heat resistance such as sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, cyano group-containing monomers, vinyl ester monomers, aromatic vinyl monomers, and hydroxyl group-containing monomers. Monomers, carboxyl group-containing monomers, acid anhydride group-containing monomers, amide group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, N-acryloylmorpholine, vinyl ether monomers, etc. It can be used as appropriate. These monomer components may be used alone or in admixture of two or more.

  Examples of the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid.

  Examples of the acid anhydride group-containing monomer include maleic anhydride and itaconic anhydride.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 8-hydroxyoctyl. (Meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl acrylate, N-methylol (meth) acrylamide, vinyl alcohol, allyl alcohol 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, and the like.

  Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth And acryloyloxynaphthalene sulfonic acid.

  Examples of the phosphate group-containing monomer include 2-hydroxyethylacryloyl phosphate.

  Examples of the cyano group-containing monomer include acrylonitrile.

  Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, vinyl laurate, and the like.

  Examples of the aromatic vinyl monomer include styrene, chlorostyrene, chloromethyl styrene, α-methyl styrene, and the like.

  Examples of the amide group-containing monomer include acrylamide and diethyl acrylamide.

  Examples of the amino group-containing monomer include N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, and the like.

  Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate and allyl glycidyl ether.

  Examples of the vinyl ether monomer include methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, and the like.

  The (meth) acrylic polymer used in the present invention is obtained by polymerizing the monomer components, and the polymerization method is not particularly limited, and is solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization. Polymerization can be performed by a known method such as turbid polymerization, and solution polymerization is more preferable from the viewpoint of workability and the like. The obtained polymer may be any of homopolymer, random copolymer, block copolymer and the like.

  The (meth) acrylic polymer used in the present invention preferably has a weight average molecular weight of 300,000 to 5,000,000, more preferably 400,000 to 4,000,000, particularly preferably 500,000 to 3,000,000. When the weight average molecular weight is less than 300,000, the adhesive strength at the time of peeling increases due to the improvement of the wettability of the transparent conductive film as the adherend to the transparent base material. The adherend may be damaged, and the adhesive force tends to be generated due to the reduced cohesive force of the pressure-sensitive adhesive layer. On the other hand, when the weight average molecular weight exceeds 5,000,000, the fluidity of the polymer is lowered, the wettability of the transparent conductive film as the adherend to the transparent substrate becomes insufficient, and the adherence between the adherend and the carrier film is reduced. There is a tendency to cause blisters occurring between the agent layer and the agent layer. In addition, a weight average molecular weight means what was obtained by measuring by GPC (gel permeation chromatography).

  Moreover, from the reason that it is easy to balance the adhesive performance, the glass transition temperature (Tg) of the (meth) acrylic polymer is preferably 0 ° C. or lower (usually −100 ° C. or higher, preferably −60 ° C. or higher). -10 ° C or lower is more preferable, -20 ° C or lower is further preferable, and -30 ° C or lower is particularly preferable. When the glass transition temperature is higher than 0 ° C., the polymer is difficult to flow, and the transparent conductive film as the adherend is not sufficiently wetted with the transparent base material, and the gap between the adherend and the adhesive layer of the carrier film Tend to cause blisters to occur. In addition, the glass transition temperature (Tg) of a (meth) acrylic-type polymer can be adjusted in the said range by changing the monomer component and composition ratio to be used suitably.

  The pressure-sensitive adhesive layer used in the present invention appropriately adjusts the (meth) acrylic polymer by appropriately adjusting the structural unit and structural ratio of the (meth) acrylic polymer, and the selection and blending ratio of the crosslinking agent described later. By cross-linking, it has excellent heat resistance.

  As the crosslinking agent used in the present invention, an isocyanate compound, an epoxy compound, a melamine resin, an aziridine derivative, a metal chelate compound, or the like is used. Among these, an isocyanate compound and an epoxy compound are particularly preferably used mainly from the viewpoint of obtaining an appropriate cohesive force. These compounds may be used alone or in combination of two or more.

  Examples of the isocyanate compound include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate, and 2,4-tolylene diisocyanate. , 4,4'-diphenylmethane diisocyanate, aromatic isocyanates such as xylylene diisocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.), trimethylolpropane / Hexamethylene diisocyanate trimer adduct (trade name: Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), hexamethylene diisocyanate Isocyanurate (trade name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.), and the like isocyanate adducts such as. These compounds may be used alone or in combination of two or more.

  Examples of the epoxy compound include N, N, N ′, N′-tetraglycidyl-m-xylenediamine (trade name: TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane (trade name: TETRAD-C, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and the like. These compounds may be used alone or in combination of two or more.

  Examples of the melamine resin include hexamethylol melamine. As aziridine derivatives, for example, the trade name HDU (manufactured by Mutual Yakuko Co., Ltd.), the brand name TAZM (manufactured by Mutual Yakuko Co., Ltd.), the brand name TAZO (manufactured by Mutual Yakuko Co., Ltd.) Is mentioned. These compounds may be used alone or in combination of two or more.

  Examples of the metal chelate compound include aluminum, iron, tin, titanium, and nickel as metal components, and acetylene, methyl acetoacetate, and ethyl lactate as chelate components. These compounds may be used alone or in combination of two or more.

  The amount of the crosslinking agent used in the present invention is preferably 1 part by weight or more, more preferably 2 parts by weight or more, based on 100 parts by weight (solid content) of the (meth) acrylic polymer. It is more preferable to exceed the weight part. Moreover, as an upper limit, it is preferable that it is 30 weight part or less, and it is more preferable that it is 25 weight part or less. When the blending amount is less than 1 part by weight, the crosslinking formation by the crosslinking agent becomes insufficient, the cohesive force of the pressure-sensitive adhesive layer becomes small, and sufficient heat resistance may not be obtained. Tend to be. On the other hand, when the blending amount exceeds 30 parts by weight, the cohesive force of the pressure-sensitive adhesive layer is large, the fluidity is lowered, and the transparent conductive film as the adherend becomes insufficiently wetted, and the adhesion This tends to cause blisters generated between the body and the pressure-sensitive adhesive layer, which is not preferable. These crosslinking agents may be used alone or in combination of two or more.

  In addition, the pressure-sensitive adhesive layer of the carrier film used in the present invention is obtained by polymerizing a monomer component containing a (meth) acrylic acid ester having an alkyl group having 2 to 14 carbon atoms and a monomer having the functional group (meta ) It is preferably formed from a pressure-sensitive adhesive composition containing an acrylic polymer and a crosslinking agent, in which case the functional group A of the monomer having the functional group and the functional group of the crosslinking agent that reacts with the functional group A The molar ratio (B / A) of B is preferably 0.70 or more, more preferably 0.75 or more, and further preferably 0.8 to 0.95. For example, when a carboxyl group-containing monomer is used as a raw material, it can react with the carboxyl groups of all cross-linking agents with respect to “the total mole number A of carboxyl groups of all carboxyl group-containing monomers used as raw material monomers”. The ratio of [the total number of moles B of functional groups] [functional group B / carboxyl group A capable of reacting with carboxyl groups] (molar ratio) is preferably 0.70 or more, more preferably 0.75 or more, and Preferably it is 0.8-0.9. By setting [functional group / carboxyl group capable of reacting with carboxyl group] to 0.70 or more, unreacted carboxyl group in the pressure-sensitive adhesive layer is reduced, resulting from the interaction between the carboxyl group and the adherend. It is preferable because an increase in peel strength (adhesive strength) over time can be effectively prevented.

For example, when 7 g of a crosslinking agent having a functional group equivalent to 110 (g / eq) of a functional group that can react with a carboxyl group is added (added), the number of moles of the functional group that can react with the carboxyl group of the crosslinking agent Can be calculated as follows, for example.
Number of moles of functional group capable of reacting with carboxyl group of crosslinking agent = [blending amount of crosslinking agent] / [functional group equivalent] = 7/110
For example, when 7 g of an epoxy crosslinking agent having an epoxy equivalent of 110 (g / eq) is added (blended) as the crosslinking agent, the number of moles of epoxy groups possessed by the epoxy crosslinking agent can be calculated as follows, for example. .
Number of moles of epoxy group possessed by epoxy-based crosslinking agent = [blending amount of epoxy-based crosslinking agent] / [epoxy equivalent] = 7/110

  Moreover, in this invention, the polyfunctional monomer which has 2 or more of radiation reactive unsaturated bonds can be mix | blended with the said crosslinking agent or independently as a crosslinking component. In such a case, the (meth) acrylic polymer is crosslinked by irradiating with radiation or the like. As a polyfunctional monomer having two or more radiation-reactive unsaturated bonds in one molecule, for example, it can be crosslinked (cured) by irradiation with radiation such as vinyl group, acryloyl group, methacryloyl group, vinylbenzyl group. Examples thereof include polyfunctional monomers having two or more kinds of one or more kinds of radiation reactivity. As the polyfunctional monomer, generally, those having 10 or less radiation-reactive unsaturated bonds are preferably used. These compounds may be used alone or in combination of two or more.

Specific examples of the polyfunctional monomer include, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and 1,6 hexane. Examples include diol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinylbenzene, and N, N′-methylenebisacrylamide.

  The blending amount of the crosslinking component is preferably 1 to 30 parts by weight, and more preferably 2 to 25 parts by weight with respect to 100 parts by weight (solid content) of the (meth) acrylic polymer.

  Examples of the radiation include ultraviolet rays, laser beams, α rays, β rays, γ rays, X rays, electron beams, and the like, and ultraviolet rays are preferably used from the viewpoints of controllability, good handleability, and cost. More preferably, ultraviolet rays having a wavelength of 200 to 400 nm are used. Ultraviolet rays can be irradiated using an appropriate light source such as a high-pressure mercury lamp, a microwave excitation lamp, or a chemical lamp. In addition, when using an ultraviolet-ray as a radiation, a photoinitiator is mix | blended with an adhesive composition.

  The photopolymerization initiator may be any substance that generates radicals or cations by irradiating ultraviolet rays having an appropriate wavelength that can trigger the polymerization reaction according to the type of the radiation-reactive component.

  Examples of radical photopolymerization initiators include benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, o-benzoylbenzoic acid methyl-p-benzoin ethyl ether, benzoin isopropyl ether, α-methylbenzoin, benzyldimethyl ketal, and trichloro Acetophenones such as acetophenone, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4′-isopropyl-2-methylpropiophenone, etc. Propiophenones, benzophenone, methylbenzophenone, p-chlorobenzophenone, benzophenones such as p-dimethylaminobenzophenone, 2-chlorothioxanthone, 2-ethyl Thioxanthones such as oxanthone and 2-isopropylthioxanthone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)- Examples include acylphosphine oxides such as (ethoxy) -phenylphosphine oxide, benzyl, dibenzosuberone, and α-acyloxime ester. These compounds may be used alone or in combination of two or more.

  Examples of the cationic photopolymerization initiator include onium salts such as aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts, organometallic complexes such as iron-allene complexes, titanocene complexes, and arylsilanol-aluminum complexes, nitro Examples include benzyl ester, sulfonic acid derivative, phosphoric acid ester, phosphoric acid ester, phenol sulfonic acid ester, diazonaphthoquinone, and N-hydroxyimide sulfonate. These compounds may be used alone or in combination of two or more. The photopolymerization initiator is usually added in an amount of 0.1 to 10 parts by weight and preferably 0.2 to 7 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer.

  Furthermore, a photopolymerization initiation assistant such as amines can be used in combination. Examples of the photopolymerization initiation assistant include 2-dimethylaminoethylbenzoate, dimethylaminoacetophenone, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ester, and the like. These compounds may be used alone or in combination of two or more. It is preferable to mix | blend 0.05-10 weight part with respect to 100 weight part of (meth) acrylic-type polymers, and, as for a polymerization start adjuvant, it is more preferable to mix | blend in the range of 0.1-7 weight part.

  Furthermore, the pressure-sensitive adhesive composition used in the present invention may contain other known additives, such as powders such as colorants and pigments, surfactants, plasticizers, and tackifiers. , Low molecular weight polymer, surface lubricant, leveling agent, antioxidant, corrosion inhibitor, light stabilizer, UV absorber, polymerization inhibitor, silane coupling agent, inorganic or organic filler, metal powder, particulate, It can mix | blend suitably according to the use which uses a foil-like thing.

  The solid content of the pressure-sensitive adhesive composition is not particularly limited and is preferably 20% by weight or more, and more preferably 30% by weight or more.

  The pressure-sensitive adhesive layer used in the present invention is formed from the pressure-sensitive adhesive composition as described above, and is preferably obtained by cross-linking the (meth) acrylic polymer with the cross-linking agent. . Moreover, the carrier film for transparent conductive films used by this invention forms such an adhesive layer on a support body. At that time, the crosslinking of the (meth) acrylic polymer is generally performed after the application of the pressure-sensitive adhesive composition, but the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition after crosslinking may be transferred to a support or the like. Is possible.

(3) Manufacturing method of carrier film for transparent conductive film Although it does not specifically limit as a method of forming the adhesive layer 1 on the support body 2, For example, the said adhesive composition is the support body 2 The adhesive layer 1 is formed on the support 2 by drying and removing the polymerization solvent and the like. Thereafter, curing may be performed for the purpose of adjusting the component transfer of the pressure-sensitive adhesive layer 1 or adjusting the crosslinking reaction. In addition, when the pressure-sensitive adhesive composition is applied on the support 2 to produce a carrier film, one or more solvents other than the polymerization solvent are added to the pressure-sensitive adhesive composition so that the carrier film can be uniformly applied on the support. You may add a new one.

  Moreover, as a coating method of the said adhesive composition, the well-known method used for manufacture of an adhesive tape etc. is used. Specific examples include roll coating, gravure coating, reverse coating, roll brushing, spray coating, and air knife coating.

  The drying conditions for drying the pressure-sensitive adhesive composition applied to the support can be appropriately determined depending on the composition, concentration, type of solvent in the composition, etc., and are not particularly limited. However, it can be dried at 20 to 200 ° C. for about 1 second to 24 hours.

In addition, when a photopolymerization initiator as an optional component is blended as described above, the pressure-sensitive adhesive layer is applied by light irradiation after coating on one or both sides of the support (base material, base material layer). Can be obtained. Usually, the pressure-sensitive adhesive layer is obtained by irradiating ultraviolet rays having an illuminance of 1 to 200 mW / cm ² at a wavelength of 300 to 400 nm and photopolymerizing them with a light amount of about 400 to 4000 mJ / cm ² .

  As for the thickness of the adhesive layer of the carrier film for transparent conductive films used by this invention, 5-50 micrometers is preferable, More preferably, it is 10-30 micrometers. Within the above range, the balance between adhesion and removability is excellent and a preferred embodiment is obtained.

2. Transparent conductive film The transparent conductive film used by this invention has the transparent conductive layer 4 and the transparent base material 5, as shown in FIG. 2, for example, and in-plane heating shrinkage | contraction rate S2 is 0.3-0. 6%. Here, the in-plane heat shrinkage rate S2 can be obtained by the same method as in the case of the in-plane heat shrinkage rate of the support. That is, it can be determined by the following method.

<In-plane heating shrinkage>
The heat shrinkage S2 _{md in} the longitudinal direction (MD direction) and the heat shrinkage S2 _td in the width direction (TD direction) of the transparent conductive film are calculated as follows. Specifically, the transparent conductive film is cut into a width of 100 mm and a length of 100 mm (test piece), a straight line with a length of 80 mm is drawn in each direction of the MD direction and the TD direction, and a cross mark is made. The length (mm) of the mark in the TD direction is measured with an Olympus digital compact measuring microscope STM5 (manufactured by Olympus Optical Co., Ltd.). Thereafter, heat treatment (140 ° C., 90 minutes) is performed. After allowing to cool for 1 hr at room temperature, the lengths of the marks in the MD direction and the TD direction are measured again, and the measured shrinkage rates in the MD direction and the TD direction are obtained by substituting the measured values into the following formulas.
Heat shrinkage S (%) = [[length of mark before heating (mm) −length of mark after heating (mm)] / length of mark before heating (mm)] × 100
The sum of the obtained MD heat shrinkage S2 _md and TD heat shrinkage S2 _td is defined as the in-plane heat shrinkage S2 (%) of the transparent conductive film.

  The in-plane heat shrinkage ratio S2 of the transparent conductive film is preferably 0.3 to 0.5%.

  The transparent substrate 5 may be anything as long as it has transparency, and examples thereof include a resin film, a substrate made of glass or the like (for example, a sheet-like, film-like, or plate-like substrate). A resin film is particularly preferred. Although the thickness of the transparent base material 5 is not specifically limited, About 10-200 micrometers is preferable and about 15-150 micrometers is more preferable.

  Although it does not restrict | limit especially as a material of the said resin film, Various plastic materials which have transparency are mentioned. For example, the materials include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins. , Polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, polyarylate resin, polyphenylene sulfide resin, and the like. Of these, polyester resins, polyimide resins and polyethersulfone resins are particularly preferable.

  In addition, the transparent substrate 5 is subjected to an etching process such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, or undercoating treatment on the surface in advance, and a transparent conductive layer provided thereon You may make it improve the adhesiveness with respect to the said transparent base materials 5, such as 4. Further, before providing the transparent conductive layer 4, dust may be removed and cleaned by solvent cleaning, ultrasonic cleaning, or the like, if necessary.

  The constituent material of the transparent conductive layer 4 is not particularly limited, and is selected from the group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium, and tungsten. A metal oxide of at least one metal is used. The metal oxide may further contain a metal atom shown in the above group, if necessary. For example, indium oxide (ITO) containing tin oxide and tin oxide containing antimony are preferably used, and ITO is particularly preferably used. As ITO, it is preferable to contain 80 to 99 weight% of indium oxide and 1 to 20 weight% of tin oxide.

  The thickness of the transparent conductive layer 4 is not particularly limited, but is preferably 10 nm or more, more preferably 15 to 40 nm, and still more preferably 20 to 30 nm.

  The method for forming the transparent conductive layer 4 is not particularly limited, and a conventionally known method can be employed. Specifically, for example, a vacuum deposition method, a sputtering method, and an ion plating method can be exemplified. In addition, an appropriate method can be adopted depending on the required film thickness.

  As thickness of the said transparent conductive film 6, 15-200 micrometers can be mentioned. Furthermore, it is preferable that it is 15-150 micrometers from a viewpoint of thin film formation, and it is more preferable that it is 15-50 micrometers. When the said transparent conductive film 6 is used by a resistive film system, the thickness of 100-200 micrometers can be mentioned, for example. In addition, when used in the electrostatic capacity method, for example, a thickness of 15 to 100 μm is suitable, in particular, a thickness of 15 to 50 μm is more preferable, and a thickness of 20 to 50 μm is more preferable in accordance with the recent demand for further thinning. .

  Moreover, an undercoat layer, an oligomer prevention layer, etc. can be provided between the transparent conductive layer 4 and the transparent base material 5 as needed.

  The transparent conductive film 6 may have a functional layer. The functional layer can be provided on the surface of the transparent conductive film on which the transparent conductive layer 4 is not provided (that is, between the transparent substrate 5 and the pressure-sensitive adhesive layer 1 in FIG. 2).

  As the functional layer, for example, an antiglare treatment (AG) layer or an antireflection (AR) layer for the purpose of improving visibility can be provided. The constituent material of the antiglare layer is not particularly limited, and for example, an ionizing radiation curable resin, a thermosetting resin, a thermoplastic resin, or the like can be used. The thickness of the antiglare treatment layer is preferably 0.1 to 30 μm. As the antireflection layer, titanium oxide, zirconium oxide, silicon oxide, magnesium fluoride, or the like is used. The antireflection layer can be provided with a plurality of layers.

  Moreover, a hard coat (HC) layer can be provided as a functional layer. As a material for forming the hard coat layer, for example, a cured film made of a curable resin such as a melamine resin, a urethane resin, an alkyd resin, an acrylic resin, or a silicone resin is preferably used. The thickness of the hard coat layer is preferably 0.1 to 30 μm. The thickness is preferably 0.1 μm or more for imparting hardness. Further, the antiglare treatment layer and the antireflection layer can be provided on the hard coat layer.

3. Characteristics and Use of Laminate The curl amount after heating the laminate of the present invention at 140 ° C. for 90 minutes is preferably 0 to ± 10 mm, and particularly preferably 0 to ± 6 mm from the viewpoint of curling resistance. preferable. When the curl amount exceeds ± 10 mm, problems such as conveyance failure may occur during use, which is not preferable. The curl amount can be measured by the method described in the examples.

  Moreover, 0.1-0.18 micrometer is preferable and 0.1-0.18 micrometer is more preferable, and the uneven | corrugated level | step difference which arises after performing the etching process to the transparent conductive film on a laminated body is more preferable. The method for measuring the etching unevenness can be performed by the method described in the examples.

  The laminate of the present invention includes a display device (liquid crystal display device, organic EL (electroluminescence) display device, PDP (plasma display panel), electronic paper, etc.) provided with an input device (touch panel, etc.), input device (touch panel, etc.). Can be suitably used in the production of a base material (member) constituting a device such as the above, or a base material (member) used in these devices, but is particularly preferably used in the production of an optical base material for a touch panel. it can. Moreover, it can be used irrespective of systems, such as a touch panel, such as a resistive film system and a capacitive system.

  The laminated body of the present invention is subjected to processing such as cutting, resist printing, etching, silver ink printing, and the like, and the resulting transparent conductive film can be used as a substrate for optical devices (optical member). The substrate for an optical device is not particularly limited as long as it is a substrate having optical characteristics. For example, a display device (liquid crystal display device, organic EL (electroluminescence) display device, PDP (plasma display panel), electronic Paper, etc.), base materials (members) constituting devices such as input devices (touch panels, etc.) or base materials (members) used in these devices.

  These substrate materials for optical devices have become stiff due to the recent trend of thinning, and have been prone to bend and deform in shape during processing and transporting processes. In the present invention, by using the carrier film, the curl of the optical device substrate can be held in an optimum range, and can be stably conveyed in the process. Further, by suppressing the shrinkage of the optical device due to the influence of the immersion in the resist solution or the developer during the etching process or the heating due to the drying, the visibility when mounted on the display can be kept good.

  Hereinafter, examples and the like specifically showing the configuration and effects of the present invention will be described, but the present invention is not limited to these.

Example 1
<Adjustment of acrylic polymer (A)>
In a four-flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 90 parts by weight of butyl acrylate (BA), 10 parts by weight of acrylic acid (AA), and 2,2′-azobis as a polymerization initiator Charge 0.2 parts by weight of isobutyronitrile and 234 parts by weight of ethyl acetate, introduce nitrogen gas with gentle stirring, perform a polymerization reaction for about 7 hours while maintaining the liquid temperature in the flask at about 63 ° C. A polymer (A) solution (30% by weight) was prepared. The acrylic polymer (A) had a weight average molecular weight of 600,000 and Tg of −50 ° C.

<Adjustment of adhesive solution>
The acrylic polymer (A) solution (30% by weight) is diluted to 20% by weight with ethyl acetate, and 100 parts by weight (solid content) of the acrylic polymer in this solution is used as an epoxy crosslinking agent (Mitsubishi). 11 parts by weight of Gas Chemical Co., Ltd. (TETRAD-C) was added, and the mixture was stirred at about 25 ° C. for about 1 minute to prepare an acrylic pressure-sensitive adhesive composition.

<Preparation of carrier film for transparent conductive film>
Polyethylene terephthalate (PET) base material (thickness: 125 μm, MD shrinkage S _md : 1.13%, TD heat shrinkage S _td : −0.11% ) And heated at 120 ° C. for 60 seconds to form an adhesive layer having a thickness of 20 μm. Next, a silicone-treated surface of a PET release liner (thickness 25 μm) having a silicone treatment on one side was bonded to the surface of the pressure-sensitive adhesive layer. The carrier film after storage for 2 days at 50 ° C. has a MD heat shrinkage S1 _md : 0.74%, a TD heat shrinkage S1 _td : −0.08%, and an in-plane heat shrinkage S1: 0. The characteristic was 66%. In use, the release liner was removed before use.

Example 2
In Example 1 <Preparation of carrier film for transparent conductive film>, the acrylic pressure-sensitive adhesive composition was applied to one side of a polyethylene terephthalate (PET) substrate and heated at 150 ° C. for 60 seconds. A carrier film was prepared in the same manner as in Example 1. The obtained carrier film had a MD heat shrinkage S1 _md : 0.59%, a TD heat shrinkage S1 _td : -0.13%, and an in-plane heat shrinkage S1: 0.46%.

Example 3
In <Preparation of Carrier Film for Transparent Conductive Film> in Example 1, the acrylic pressure-sensitive adhesive composition was made of a polyethylene terephthalate (PET) substrate (thickness: 125 μm, MD shrinkage S _md : 0.72 %, A heat shrinkage ratio in the TD direction _Std : 0.31%) A carrier film was produced in the same manner as in Example 1 except that it was applied on one side. The obtained carrier film had a MD heat shrinkage S1 _md : 0.41%, a TD heat shrinkage S1 _td : 0.13%, and an in-plane heat shrinkage S1: 0.54%.

Example 4
In Example 3 <Preparation of carrier film for transparent conductive film>, the acrylic pressure-sensitive adhesive composition was applied to one side of a polyethylene terephthalate (PET) substrate and heated at 150 ° C. for 60 seconds. A carrier film was prepared in the same manner as in Example 3. The obtained carrier film had a heat shrinkage ratio S1 _{md in the} MD direction of 0.39%, a heat shrinkage ratio S1 _{td in the} TD direction of 0.08%, and an in-plane heat shrinkage ratio of S1: 0.47%.

Comparative Example 1
In Example 1 <Preparation of Carrier Film for Transparent Conductive Film>, the acrylic pressure-sensitive adhesive composition was applied to one side of the release liner (side that had been subjected to silicone treatment) and heated at 150 ° C. for 60 seconds. Thus, a pressure-sensitive adhesive layer having a thickness of 20 μm was formed. Next, a polyethylene terephthalate (PET) base material (thickness: 125 μm, heat shrinkage S _{md in} MD direction: 1.13%, heat shrinkage S _{td in} TD direction: −0.11 on the surface of the pressure-sensitive adhesive layer. %). The carrier film after being stored at 50 ° C. for 2 days has a MD heat shrinkage S1 _md : 1.02%, a TD heat shrinkage S1 _td : −0.10%, and an in-plane heat shrinkage S1: 0. The characteristic was 92%.

Comparative Example 2
In <Preparation of Carrier Film for Transparent Conductive Film> in Example 1, the acrylic pressure-sensitive adhesive composition was subjected to an annealed polyethylene terephthalate (PET) base material (thickness: 125 μm, heat shrinkage S _{md in the} MD direction). : 0.12%, heat shrinkage ratio in the TD direction _Std : 0.03%) A carrier film was produced in the same manner as in Example 1 except that the film was applied on one side. The obtained carrier film had a MD heat shrinkage S1 _md : 0.08%, a TD heat shrinkage S1 _td : 0.01%, and an in-plane heat shrinkage S1: 0.09%.

<Measurement of weight average molecular weight (Mw) of acrylic polymer>
The weight average molecular weight of the produced polymer was measured by GPC (gel permeation chromatography).

Device: HLC-8220GPC, manufactured by Tosoh Corporation
column:
Sample column: TSK guard column Super HZ-H manufactured by Tosoh Corporation
(1) + TSKgel Super HZM-H (2)
Reference column; manufactured by Tosoh Corporation, TSKgel Super H-RC (1)
Flow rate: 0.6ml / min
Injection volume: 10 μl
Column temperature: 40 ° C
Eluent: THF
Injection sample concentration: 0.2% by weight
Detector: differential refractometer The weight average molecular weight was calculated in terms of polystyrene.

<Measurement of glass transition temperature (Tg)>
The glass transition temperature (Tg) (° C.) was determined by the following formula using the following literature values as the glass transition temperature Tgn (° C.) of the homopolymer of each monomer.

Formula: 1 / (Tg + 273) = Σ [Wn / (Tgn + 273)]
(Wherein, Tg (° C.) is the glass transition temperature of the copolymer, Wn (−) is the weight fraction of each monomer, Tgn (° C.) is the glass transition temperature of the homopolymer of each monomer, and n is the type of each monomer. Represents.)
2-ethylhexyl acrylate (2EHA): -70 ° C
Butyl acrylate (BA): -55 ° C
Acrylic acid: 106 ° C
In addition, as a reference value, “Synthesis / design of acrylic resin and development of new application” (measured at the Central Management Development Center).

<Heat shrinkage>
(1) Heat shrinkage rate in the MD direction and TD direction of the support Heat shrinkage rate S1 _{md in} the longitudinal direction (MD direction) and heat shrinkage rate S1 _td in the width direction (TD direction) of the support were calculated as follows. . Specifically, a carrier film composed of a pressure-sensitive adhesive layer to which a separator is bonded and a support is cut into a size of 100 mm in width and 100 mm in length (test piece), and in the MD and TD directions on the support side. A straight line with a length of 80 mm was drawn in the direction of, and a cross mark was made, and the lengths (mm) of the marks in the MD direction and the TD direction were measured with an Olympus digital compact measuring microscope STM5 (manufactured by Olympus Optical Co., Ltd.). Then, after peeling off a separator, the test piece was set | placed in the state which faced the adhesive layer, and the heat processing (140 degreeC, 90 minutes) were performed. After allowing to cool at room temperature for 1 hr, the lengths of the marks in the MD direction and the TD direction were measured again, and the measured shrinkage rates in the MD direction and the TD direction were determined by substituting the measured values into the following equations.
Heat shrinkage S (%) = [[length of mark before heating (mm) −length of mark after heating (mm)] / length of mark before heating (mm)] × 100
The heat shrinkage S1 _{md in} the MD direction and the heat shrinkage S1 _td in the TD direction of the support were determined.

(2) Heat shrinkage rate in the MD direction and TD direction of the transparent conductive film The heat shrinkage rate S2 _{md in} the longitudinal direction (MD direction) and the heat shrinkage rate S2 _td in the width direction (TD direction) of the transparent conductive film are as follows. Calculated as follows. Specifically, the transparent conductive film is cut into a width of 100 mm and a length of 100 mm (test piece), a straight line with a length of 80 mm is drawn in each direction of the MD direction and the TD direction, and a cross mark is made. The length (mm) of the mark in the TD direction was measured with an Olympus digital compact measuring microscope STM5 (manufactured by Olympus Optical Co., Ltd.). Thereafter, heat treatment (140 ° C., 90 minutes) was performed. After allowing to cool at room temperature for 1 hr, the lengths of the marks in the MD direction and the TD direction were measured again, and the measured shrinkage rates in the MD direction and the TD direction were determined by substituting the measured values into the following equations.
Heat shrinkage S (%) = [[length of mark before heating (mm) −length of mark after heating (mm)] / length of mark before heating (mm)] × 100
The heat shrinkage S2 _{md in} the MD direction and the heat shrinkage S2 _{td in the} TD direction of the transparent conductive film were determined.

(3) In-plane heating shrinkage The in-plane heating shrinkage of the support and the transparent conductive film was determined by the following formula.
In-plane heating shrinkage S1 (%) of support = S1 _md + S1 _td
In-plane heating shrinkage S2 (%) of transparent conductive film = S2 _md + S2 _td

<Curl resistance>
Transparent conductive film 1 in which an ultrathin ITO layer (film thickness: 30 nm) is formed on a PET substrate having a thickness of 100 μm (MD heat shrinkage: 0.48%, TD heat shrinkage: −0 .13%) on the PET substrate side, the carrier film for transparent conductive film obtained in Examples and Comparative Examples (the adhesive layer of the carrier film and the PET substrate of the transparent conductive film are bonded together) As shown in FIG. After heating at 140 ° C. for 90 minutes with the ITO surface facing up, it was allowed to cool at room temperature (23 ° C.) for 1 hour. Then, place the sample on a horizontal surface with the ITO layer on top, measure the height (mm) from the horizontal plane at the four corners of the laminate, and use the average value (mm) as the curl value did. The measurement sample was evaluated at n3. Moreover, about the carrier film for transparent conductive films obtained in Example 1, the transparent conductive film 2 (MD direction) which formed the ultra-thin ITO layer (film thickness: 30 nm) on the PET base material of 100 micrometers in thickness The heat-shrinkage ratio of 0.41% and the heat-shrinkage ratio in the TD direction: -0.32% were similarly evaluated for the curl resistance. This was designated as Comparative Example 3.

  Curling resistance is particularly preferred when the absolute value of the measured value is 0 to 6 mm, and curling resistance is preferred when the measured value is greater than 6 mm and not more than 10 mm. On the other hand, when the absolute value of the measured value exceeds 10 mm, a problem in curling resistance is expected to occur.

<Etching unevenness>
Transparent conductive film 1 in which an ultrathin ITO layer (film thickness: 30 nm) is formed on a PET substrate having a thickness of 100 μm (MD heat shrinkage: 0.48%, TD heat shrinkage: −0 .13%) on the PET substrate side, the carrier film for transparent conductive film obtained in Examples and Comparative Examples (the adhesive layer of the carrier film and the PET substrate of the transparent conductive film are bonded together) As shown in FIG. The cut sample was heat-treated at 140 ° C. for 90 minutes with the ITO surface being the upper surface and allowed to cool for 5 minutes. Twenty commercially available polyimide tapes (2 mm width) were bonded to the ITO surface at a 2 mm pitch. Next, a container containing hydrochloric acid was immersed in a water bath, and the temperature was kept constant so that the hydrochloric acid reached 50 ° C. The sample was immersed in hydrochloric acid at 50 ° C. and left for 5 minutes, and then washed with water. After confirming that the ITO layer was etched by surface resistance, the polyimide tape was peeled off. Thereafter, a drying treatment was performed at 140 ° C. for 30 minutes. Moreover, about the carrier film for transparent conductive films obtained in Example 1, the transparent conductive film 2 (MD direction) which formed the ultra-thin ITO layer (film thickness: 30 nm) on the PET base material of 100 micrometers in thickness The etching unevenness step was evaluated in the same manner for the heat shrinkage ratio of 0.41% and the heat shrinkage ratio in the TD direction of -0.32%. This was designated as Comparative Example 3.

The level difference was measured as follows.
Apparatus: Optical profiler NT9100 (manufactured by Veeco) Measurement conditions: Measurement Type: VSI (Infinite Scan), Objective: 2.5X, FOV: 1.0X, Modulation Threshold: 0.5%.

  In addition, the uneven | corrugated level | step difference of cross-sectional profile was actually measured based on the image of 5 mm x 1.8 mm size using a stitching function. Samples were evaluated at n3.

  When the measurement value is 0.1 to 0.15 μm, the evaluation of the uneven step is “◯”, and when the measurement value is more than 0.15 μm and 0.19 μm or less, “△”, and more than 0.19 μm is “ × ”.

<Pattern visibility>
The etching step evaluation sample was placed on a black acrylic plate and allowed to stand under a fluorescent lamp. While moving the sample on the black acrylic plate, it was visually evaluated whether the reflected fluorescent lamp image appeared to be distorted stepwise.
When the fluorescent lamp image looks straight: ◎
If the fluorescent light image appears to be slightly distorted in steps: ○
If the fluorescent lamp image appears clearly distorted in a staircase pattern: ×
In the above evaluation results, it was judged that な し and ○ were no problem and × was not acceptable.

  As is clear from the results in Table 1 above, in all examples, the curl resistance was good, and the pattern visibility and etching unevenness were excellent.

  On the other hand, in the case of the comparative example, the curl resistance was low, the transparent conductive film was extremely uneven, and it was at a level that caused problems in transportability. In Comparative Example 1, there was a problem in pattern visibility and etching level difference, and in Comparative Example 2 and Comparative Example 3, there was a problem in curling resistance.

DESCRIPTION OF SYMBOLS 1 Adhesive layer 2 Support body 3 Carrier film for transparent conductive films 4 Transparent conductive layer 5 Transparent base material 6 Transparent conductive film 7 Laminate

Claims (7)

Including a carrier film for a transparent conductive film having an adhesive layer on at least one surface of a support, and a transparent conductive film having a transparent conductive layer and a transparent substrate,
In-plane heating shrinkage S1 when heated at 140 ° C. for 90 minutes of the support is 0.3 to 0.9%,
The in-plane heat shrinkage S2 when heated at 140 ° C. for 90 minutes of the transparent conductive film is 0.3 to 0.6%,
The said adhesive layer is an adhesive layer formed from an acrylic adhesive composition, The laminated body characterized by the above-mentioned. The laminate according to claim 1, wherein the support has a thickness of more than 70 μm and 200 μm or less. 3. The laminate according to claim 1, wherein a heat shrinkage ratio S1 _{md in} a longitudinal direction when the support is heated at 140 ° C. for 90 minutes is 0.9% or less. The laminate according to any one of claims 1 to 3, wherein a heating shrinkage S1 _{td in} the width direction when the support is heated at 140 ° C for 90 minutes is 0.6% or less. The laminate according to any one of claims 1 to 4, wherein the support is a polyester resin film. The said adhesive layer is formed from the adhesive composition containing a base polymer and a crosslinking agent, The laminated body in any one of Claims 1-5 characterized by the above-mentioned. Laminating the carrier film for transparent conductive film and the transparent conductive film so that the adhesive layer of the carrier film for transparent conductive film and the transparent substrate of the transparent conductive film are bonded together The laminate according to any one of claims 1 to 6, wherein

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