JP2017043710A - Adhesive composition, adhesive layer, carrier film for transparent conductive film, and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition having a good pot life while controlling gelation, having excellent adhesiveness and removability with respect to an adherend, exhibiting excellent workability since a difference in an adhesive force is small between fast peeling and slow peeling, and capable of suppressing development of white irregularity.SOLUTION: The adhesive composition comprises: a (meth)acrylic polymer comprising an alkyl (meth)acrylate, a hydroxyl group-containing monomer A having a glass transition temperature of 50°C or higher in a homopolymer thereof, and a hydroxyl group-containing monomer B having a glass transition temperature of lower than 50°C in a homopolymer thereof, as monomer units; and a crosslinking agent. A weight ratio ((hydroxyl group-containing monomer A)/(hydroxyl group-containing monomer B)) of the hydroxyl group-containing monomer A to the hydroxyl group-containing monomer B is 1 to 10. The crosslinking agent is included by less than 20 parts by weight with respect to 100 parts by weight of the (meth)acrylic polymer. A carrier film 3 for a transparent conductive film is provided, which uses an adhesive layer 1 formed of the above adhesive composition.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pressure-sensitive adhesive composition and a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. Moreover, this invention relates to the carrier film for transparent conductive films which has a support body and the said adhesive layer. Moreover, this invention relates to the laminated body which has the said carrier film for transparent conductive films, 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. Currently, ITO thin films (In / Sn composite oxide), metal thin films such as silver and copper, and silver nanowire thin films are used as materials for the transparent electrodes. Moreover, in the said touch panel etc., various optical films, such as a polarizing plate, are laminated | stacked through the adhesion layer other than the film base material which provides a transparent electrode.

  Various optical films such as a film substrate and a polarizing plate provided with the transparent electrode are used with a surface protective film and the like bonded together for the purpose of preventing scratches, dirt, etc. in the processing step and the transport step. There are many cases. The surface protective film is generally formed from a support and a pressure-sensitive adhesive layer formed on the support.

  In particular, due to recent demands for thinning displays and the like, the ITO thin film and polarizing plate are also thinned, so that scratches and cracks are likely to occur, and the need for protection with a surface protective film has been improved. .

  As an adhesive film for surface protection used for such an optical member, for example, two types of (meth) acrylic polymers having different glass transition temperatures are used at a specific blending ratio, and the degree of crosslinking by a crosslinking agent is adjusted. A surface protection sheet having a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive (see Patent Document 1), an acrylic copolymer formed from a monomer component containing a specific amount of 2-ethylhexyl acrylate and hydroxyethyl methacrylate, and A pressure-sensitive adhesive film in which a pressure-sensitive adhesive layer obtained from a pressure-sensitive adhesive solution containing a specific amount of a polyfunctional isocyanate crosslinking agent is provided on one side of a plastic film (see Patent Document 2) is known.

JP 2005-146151 A JP2012-21164A

  The pressure-sensitive adhesive layer forming the surface protective pressure-sensitive adhesive film described in Patent Literatures 1 and 2 includes a hydroxyl group-containing monomer having a glass transition temperature of less than 50 ° C. and a hydroxyl group having a glass transition temperature of 50 ° C. or higher. What contains both of the contained monomers is not disclosed, and the adhesive film described in Patent Documents 1 and 2 is exposed to a high temperature environment (for example, at 140 ° C. for 90 minutes) in a state of being bonded to the adherend. Then, the peeling force was increased (heavy peeling), and the removability was poor.

  By the way, when peeling a surface protection film from a to-be-adhered body, there exists a tendency for the adhesive force at the time of peeling at high speed to become higher than the adhesive force at the time of peeling at low speed. In many cases, the surface protective film is peeled off manually, and generally, an operator often peels off at a high speed. Therefore, the surface protective film is hardly peeled off and the workability may be inferior. Furthermore, the film may be broken or broken during peeling. In general, such manual peeling is often performed at a constant peeling speed so that peeling is initially performed at a low speed and then gradually performed at a high speed. In such a case, if there is a large difference in adhesive strength between low-speed peeling and high-speed peeling, there is a risk that the film may break during the peeling or the adherend may crack. However, a surface protective film having a certain adhesive strength has been desired.

  In addition, it is known that when the surface protective film is lightly peeled (removal strength is reduced), the amount of the crosslinking agent in the pressure-sensitive adhesive composition is usually increased to achieve light peeling. However, when the addition amount of the cross-linking agent is increased, the pressure-sensitive adhesive composition is rapidly gelled and the pot life is shortened. In addition, if a large amount of a crosslinking agent is added to the pressure-sensitive adhesive composition, microphase separation occurs, and white unevenness may occur on the surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, resulting in poor appearance. There was a case.

  In particular, since the thickness of the transparent conductive film such as the ITO thin film tends to decrease year by year, the surface protective film is used for protecting such a transparent conductive film (that is, the carrier for the transparent conductive film). In the case of being used as a film, the problem of crack generation at the time of peeling was remarkable.

  Therefore, the present invention is a pressure-sensitive adhesive composition that has a good pot life by controlling gelation, has excellent adhesion and re-peelability to the adherend, and has an adhesive force with high-speed peeling and low-speed peeling. It is an object of the present invention to provide a pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive layer capable of forming a pressure-sensitive adhesive layer capable of suppressing the occurrence of white unevenness. Further, the present invention is a laminate comprising a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, a carrier film for a transparent conductive film using the pressure-sensitive adhesive layer, the carrier film for a transparent conductive film, and a transparent conductive film. It is also intended to provide a body.

  The present inventors diligently studied to achieve the above object, and as a result, found that the above object can be achieved by using the following pressure-sensitive adhesive composition, and completed the present invention.

That is, the present invention contains alkyl (meth) acrylate, a hydroxyl group-containing monomer A having a glass transition temperature of 50 ° C. or higher as a homopolymer, and a hydroxyl group-containing monomer B having a glass transition temperature of less than 50 ° C. as monomer units. Including a (meth) acrylic polymer and a crosslinking agent,
The weight ratio of the hydroxyl group-containing monomer A and the hydroxyl group-containing monomer B (hydroxyl group-containing monomer A / hydroxyl group-containing monomer B) is 1 to 10,
The crosslinking agent is less than 20 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer.

  Monomer component in which the total amount of the hydroxyl group-containing monomer A having a glass transition temperature of the homopolymer of 50 ° C. or higher and the hydroxyl group-containing monomer B having a glass transition temperature of less than 50 ° C. of the homopolymer constitutes the (meth) acrylic polymer. It is preferable that it is 10-30 weight% with respect to the whole quantity.

  The crosslinking agent is preferably an aliphatic polyisocyanate.

  It is preferable that the aliphatic polyisocyanate contains hexamethylene diisocyanate.

  The pressure-sensitive adhesive composition of the present invention is preferably used for forming the pressure-sensitive adhesive layer of a carrier film for a transparent conductive film having a pressure-sensitive adhesive layer on at least one side of a support.

  The present invention also provides a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, and a transparent conductive film characterized by having the pressure-sensitive adhesive layer on at least one side of a support. It relates to a carrier film.

Furthermore, the present invention is a laminate having a transparent conductive film laminated on the carrier film for transparent conductive film and the carrier film for transparent conductive film,
The transparent conductive film has a transparent conductive layer and a transparent substrate,
The present invention relates to a laminate, wherein the adhesive surface of the adhesive layer of the carrier film for transparent conductive film is bonded to the surface of the transparent substrate opposite to the surface in contact with the transparent conductive layer.

  The pressure-sensitive adhesive composition of the present invention is excellent in adhesion and re-peelability to an adherend, forms a pressure-sensitive adhesive layer that is excellent in workability with a small difference in adhesive force between high-speed peeling and low-speed peeling, and can suppress white unevenness. be able to. Moreover, since the adhesive composition of this invention has few addition amounts of a crosslinking agent, it can control gelatinization and has a favorable pot life. Such an adhesive composition of this invention can be used suitably for adhesive layer formation of the carrier film for transparent conductive films. Furthermore, this invention can provide the laminated body containing the carrier film for transparent conductive films using the said adhesive layer, and the said carrier film. By using the carrier film for transparent conductive film of the present invention, the transparent conductive film as an adherend is not wrinkled or scratched, and the shape of the transparent conductive film can be maintained. .

It is a schematic diagram which shows one Embodiment of the carrier film for transparent conductive films of this invention. It is a schematic diagram which shows one Embodiment of the laminated body which affixed the transparent conductive film on the adhesive layer surface of the carrier film for transparent conductive films of this invention. It is a schematic diagram which shows one Embodiment of the laminated body which affixed the transparent conductive film with a functional layer on the adhesive layer surface of the carrier film for transparent conductive films of this invention.

1. Pressure-sensitive adhesive composition The pressure-sensitive adhesive composition of the present invention comprises an alkyl (meth) acrylate, a homopolymer having a glass transition temperature of 50 ° C. or higher, and a hydroxyl group-containing monomer A (hereinafter sometimes simply referred to as “hydroxyl group-containing monomer A”), And a (meth) acrylic polymer containing a monomer unit of a hydroxyl group-containing monomer B having a glass transition temperature of less than 50 ° C. (hereinafter sometimes simply referred to as “hydroxy group-containing monomer B”),
The weight ratio of the hydroxyl group-containing monomer A and the hydroxyl group-containing monomer B (hydroxyl group-containing monomer A / hydroxyl group-containing monomer B) is 1 to 10,
The crosslinking agent is less than 20 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer.

  The (meth) acrylic polymer is obtained by polymerizing a monomer component including an alkyl (meth) acrylate, a hydroxyl group-containing monomer A having a Tg of 50 ° C. or more, and a hydroxyl group-containing monomer B having a Tg of less than 50 ° C. The weight ratio of the hydroxyl group-containing monomer A having a Tg of 50 ° C. or more to the hydroxyl group-containing monomer B having a Tg of less than 50 ° C. (hydroxyl group-containing monomer A / hydroxyl group-containing monomer B) is obtained. 1-10. When the hydroxyl group-containing monomer A / hydroxyl group-containing monomer B is 1 to 10, even if the addition amount of the crosslinking agent in the pressure-sensitive adhesive composition is small, it is possible to express an appropriate adhesive force at high-speed peeling and low-speed peeling. . Moreover, since the addition amount of the crosslinking agent can be reduced, the pressure-sensitive adhesive composition can be prevented from gelation, and further, white unevenness on the surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition can be prevented. .

  As said alkyl (meth) acrylate, what has a C1-C14 alkyl group can be used, for example, As a main monomer component of an alkyl (meth) acrylate, C4-C14 of an alkyl group is used. Are preferred, alkyl (meth) acrylates having 6 to 14 carbon atoms are more preferred, and alkyl (meth) acrylates having 6 to 9 carbon atoms are particularly preferred. Here, the main monomer is 50% by weight or more, more preferably 60% by weight or more, and still more preferably 80% by weight or more based on the total amount of “alkyl (meth) acrylate” contained in the monomer component. Particularly preferably 100% by weight. Note that (meth) acrylate refers to acrylate and / or methacrylate, and (meth) of the present invention has the same meaning.

  Examples of the alkyl (meth) acrylate having an alkyl group having 1 to 14 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate (BA), and 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. 1 type In Germany, or two or more may be used in combination. Among these, n-butyl (meth) acrylate (BA) and 2-ethylhexyl (meth) acrylate (2EHA) are preferable, and 2-ethylhexyl (meth) acrylate (2EHA) is particularly preferable.

  In particular, when light peeling is required for the pressure-sensitive adhesive layer, it is preferable to use an alkyl (meth) acrylate having an alkyl group having 6 to 14 carbon atoms, and an alkyl having an alkyl group having 6 to 14 carbon atoms ( The (meth) acrylate is preferably 50% by weight or more, more preferably 60% by weight or more, and still more preferably 80% by weight or more based on the total amount of the alkyl (meth) acrylate.

  The content of the alkyl (meth) acrylate is preferably 65% by weight, more preferably 75% by weight or more, and more preferably 80% by weight or more with respect to the total amount of monomer components constituting the (meth) acrylic polymer. Further preferred.

  The hydroxyl group-containing monomer A having a homopolymer Tg of 50 ° C. or higher is a polymerizable functional group having a homopolymer Tg of 50 ° C. or higher and having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Examples thereof include those having a group and a hydroxyl group. Specifically, 2-hydroxyethyl methacrylate (Tg of homopolymer: 55 ° C.), N-methylolacrylamide (Tg of homopolymer: 110 ° C.), N- (2-hydroxyethyl) acrylamide (Tg of homopolymer: 98) ° C) and the like, and these can be used alone or in combination of two or more. Among these, 2-hydroxyethyl methacrylate (Tg of homopolymer: 55 ° C.) is preferable from the viewpoint that appropriate adhesive strength can be expressed by low-speed peeling and high-speed peeling.

  Further, the glass transition temperature of the homopolymer of the hydroxyl group-containing monomer A may be 50 ° C. or higher, but is preferably 50 to 150 ° C., more preferably 50 to 100 ° C., and more preferably 50 to 90 ° C. It is more preferable that the temperature is 0 ° C. because an appropriate adhesive strength can be expressed by low-speed peeling and high-speed peeling.

  As the hydroxyl group-containing monomer B having a glass transition temperature of less than 50 ° C., the homopolymer has a glass transition temperature of less than 50 ° C. and has an unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Examples thereof include those having a polymerizable functional group and containing a hydroxyl group. Specifically, 2-hydroxyethyl acrylate (homopolymer Tg: −15 ° C.), 2-hydroxypropyl methacrylate (homopolymer Tg: 26 ° C.), 2-hydroxypropyl acrylate (homopolymer Tg: −7 ° C.) ), 4-hydroxybutyl acrylate (homopolymer Tg: −32 ° C.), etc., hydroxyalkyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl acrylate (homopolymer Tg: 17 ° C.), 1,4-cyclohexane (Meth) acrylate having a cyclic structure such as dimethanol monoacrylate (Tg of homopolymer: 18 ° C.), polyethylene glycol monoacrylate (mole number of ethylene glycol: 10, homopolymer Tg: −64 ° C.), polypropylene glycol mono Accel Relay (Meth) acrylates having an alkylene oxide structure such as propylene glycol (number of moles of propylene glycol: 6, homopolymer Tg: −59 ° C.), etc., and these may be used alone or in combination of two or more. Can be used. Among these, 4-hydroxybutyl acrylate (homopolymer Tg: −32 ° C.) is preferable from the viewpoint that appropriate adhesive strength can be exhibited by low speed peeling and high speed peeling.

  Further, the glass transition temperature of the homopolymer of the hydroxyl group-containing monomer B may be less than 50 ° C., for example, preferably 30 ° C. or less, more preferably −40 to 30 ° C., and more preferably −40 to 30 ° C. It is more preferable that the temperature is 0 ° C. because appropriate adhesive strength can be expressed by low-speed peeling and high-speed peeling.

  The weight ratio (hydroxyl group-containing monomer A / hydroxyl group-containing monomer B) of the hydroxyl group-containing monomer A whose Tg of the homopolymer is less than 50 ° C. and the hydroxyl group-containing monomer B whose homopolymer Tg is 50 ° C. or more is 1-10, It is preferably 1-9, more preferably 1.5-8, and even more preferably 1.5-6. When the hydroxyl group-containing monomer A / hydroxyl group-containing monomer B is within the above range, even if the addition amount of the cross-linking agent in the pressure-sensitive adhesive composition is small, it is possible to express an appropriate adhesive force with high-speed peeling and low-speed peeling. Moreover, since the addition amount of the crosslinking agent can be reduced, the pressure-sensitive adhesive composition can be prevented from gelation, and further, white unevenness on the surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition can be prevented. .

  The content of the hydroxyl group-containing monomer A having a glass transition temperature of 50 ° C. or higher of the homopolymer is preferably 5 to 27% by weight based on the total amount of monomer components constituting the (meth) acrylic polymer. It is more preferably ˜18% by weight, and further preferably 9 to 15% by weight. When the content ratio of the hydroxyl group-containing monomer A is less than 5% by weight, 20 parts by weight or more of a crosslinking agent is required for light release, and as a result, gelation of the pressure-sensitive adhesive composition is promoted, and the pot life is increased. May be shorter. Moreover, white unevenness may occur in the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. On the other hand, when the content ratio of the hydroxyl group-containing monomer A exceeds 27% by weight, the reactivity during polymerization is deteriorated, which is not preferable.

  The content of the hydroxyl group-containing monomer B having a glass transition temperature of less than 50 ° C. of the homopolymer is preferably 1 to 15% by weight with respect to the total amount of monomer components constituting the (meth) acrylic polymer. It is more preferably ˜15% by weight, and further preferably 2 to 10% by weight. When the content ratio of the hydroxyl group-containing monomer B is less than 1% by weight, the adhesive strength is excessively increased, which is not preferable. On the other hand, when the content ratio of the hydroxyl group-containing monomer B exceeds 15% by weight, the adhesive strength is excessively lowered, which is not preferable.

  The total amount of the hydroxyl group-containing monomer A and the hydroxyl group-containing monomer B is preferably 10 to 30% by weight, and 14 to 20% by weight, based on the total amount of monomer components constituting the (meth) acrylic polymer. More preferably. It is preferable that the total blending amount of the hydroxyl group-containing monomer A and the hydroxyl group-containing monomer B is within the above range, since appropriate adhesive strength can be expressed by high-speed peeling and low-speed peeling. On the other hand, when the total blending amount exceeds 30% by weight, the number of reaction points is too large, so that the crosslinking density increases and the adhesive strength tends to decrease too much. In that case, since the adhesiveness with respect to adherends, such as a transparent conductive film, will fall, it is unpreferable.

  The monomer component may contain other polymerizable monomers other than the alkyl (meth) acrylate and the hydroxyl group-containing monomers A and B. As said other polymerizable monomer, the polymerizable monomer for adjusting the glass transition point and peelability of a (meth) acrylic-type polymer etc. can be used in the range which does not impair the effect of this invention. Other polymerizable monomers may be used alone or in combination, but the blending amount of the other polymerizable monomer is preferably 10% by weight or less, preferably 5% by weight or less based on the total amount of the monomer components. Is more preferable.

  Examples of the polymerizable monomer include carboxyl group-containing monomers. The carboxyl group-containing monomer can be used from the viewpoint that the crosslinking reaction can be carried out more efficiently and the adhesive force at high speed peeling can be lowered. Examples of the carboxyl group-containing monomer include those having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, and containing a carboxyl group. (Meth) acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and the like. Among these carboxyl group-containing monomers, acrylic acid is preferred from the viewpoints of polymerizability, cohesiveness, cost, and versatility.

  The content of the carboxyl group-containing monomer is preferably 0.20% by weight or less, more preferably 0.10% by weight or less based on the total amount of the monomer components. It is preferable that the content of the carboxyl group-containing monomer is in the above-mentioned range since there is an effect of reducing the adhesive strength at high speed peeling.

  Examples of the other polymerizable monomers include 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 acid anhydrides. A monomer component having a functional group serving as a crosslinking base point, such as a group-containing monomer, an amide group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, N-acryloylmorpholine, or a vinyl ether monomer, can be used as appropriate. These monomer components may be used alone or in admixture of two or more.

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

  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 ) Acrylyloxynaphthalene sulfonic acid and the like.

  Examples of the phosphoric acid group-containing monomer include 2-hydroxyethylacryloyl phosphate, 2- (phosphonooxy) ethyl methacrylate, 3-chloro-2- (phosphonooxy) propyl methacrylate, and the like.

  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 a homopolymer, a random copolymer, a 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 2,000,000, particularly preferably 500,000 to 1,000,000. 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 wettability to the adherend, which may cause damage to the adherend in the peeling process (re-peeling). In addition, there is a tendency for adhesive residue to occur 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 wetting to the adherend becomes insufficient, and it causes the swelling generated between the adherend and the adhesive layer. Tend. In addition, a weight average molecular weight means what was obtained by measuring by GPC (gel permeation chromatography).

  In addition, 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 −70 ° 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, the wetting to the adherend is insufficient, and there is a tendency to cause blisters generated between the adherend and the pressure-sensitive adhesive layer. 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 composition of the present invention contains the (meth) acrylic polymer and a crosslinking agent. As the crosslinking agent, 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 is 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 compounds having at least two isocyanate groups. For example, aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates and the like are generally used. In the present invention, an aliphatic polyisocyanate can be preferably used from the viewpoint of ensuring removability and stability of adhesive strength, but alicyclic polyisocyanate and aromatic polyisocyanate have removability and adhesive strength stability. It is preferable not to use from the viewpoint of ensuring.

  Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethyl. Hexamethylene diisocyanate and the like can be mentioned, and among these, an aliphatic polyisocyanate containing hexamethylene diisocyanate is preferable from the viewpoint of ensuring removability and stable adhesive strength.

  As a commercial item of an isocyanate type crosslinking agent, brand name "Coronate HL", "Coronate HX" (above, Nippon Polyurethane Industry Co., Ltd. product); Trade name "Takenate D-160N", "Takenate D-165N" , “Takenate D-170HN”, “Takenate D-178N” (manufactured by Mitsui Chemicals, Inc.) and the like. These compounds may be used alone or in combination of two or more.

  These isocyanate-based crosslinking agents may be used alone or in combination of two or more, and a bifunctional isocyanate compound and a trifunctional or higher isocyanate compound may be used in combination.

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 an aziridine derivative, for example, a trade name HDU (manufactured by Mutual Yakuko Co., Ltd.), a brand name TAZM (manufactured by Mutual Yakuko Co., Ltd.), a 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, titanium, nickel, zirconium and the like as the metal component, and acetylene, methyl acetoacetate, ethyl acetoacetate, ethyl lactate, acetylacetone and the like as the chelate component. These compounds may be used alone or in combination.

  In this invention, the compounding quantity of a crosslinking agent is less than 20 weight part with respect to 100 weight part of (meth) acrylic-type polymers, It is preferable that it is 5 weight part or more and less than 20 weight part, and is 10-19 weight part. More preferably, it is 15 to 19 parts by weight. When the amount of the crosslinking agent is 20 parts by weight or more, the pressure-sensitive adhesive composition is quickly gelled and the pot life is short, so that workability is lowered. Further, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition to which 20 parts by weight or more of the crosslinking agent was added had white unevenness on the surface, and the appearance was inferior. Further, it is preferable to add 5 parts by weight or more of a cross-linking agent because appropriate adhesive force can be expressed by high-speed peeling and low-speed peeling, and the difference in adhesive force between high-speed peeling and low-speed peeling can be reduced.

  In the present invention, two or more kinds of the above-mentioned crosslinking agents can be mixed and used, and in that case, the total amount used only needs to be within the above range. Further, as described above, in the present invention, it is preferable to use an isocyanate crosslinking agent, and the ratio of the isocyanate crosslinking agent in the total amount of the crosslinking agent is preferably 50% by weight or more, more preferably 70% by weight or more. 90% by weight or more is more preferable, and it is particularly preferable to use the isocyanate-based crosslinking agent alone.

  In addition to the (meth) acrylic polymer, a polyfunctional monomer having two or more radiation-reactive unsaturated bonds can be added to the pressure-sensitive adhesive composition of the present invention. The polyfunctional monomer can be used as a monomer component when preparing the (meth) acrylic polymer. In such a case, the (meth) acrylic polymer is crosslinked by irradiating 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 a vinyl group, an acryloyl group, a methacryloyl group, or a vinylbenzyl group. Examples thereof include polyfunctional monomers having two or more radiation-reactive unsaturated bonds of one kind or two or more kinds. 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- Examples thereof include xanthdiol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinylbenzene, N, N′-methylenebisacrylamide and the like.

  The blending amount of the polyfunctional monomer is preferably 30 parts by weight or less with respect to 100 parts by weight (solid content) of the (meth) acrylic polymer.

  Examples of the radiation include ultraviolet rays, laser rays, α rays, β rays, γ rays, X rays, electron rays, 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, benzyl dimethyl ketal, 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-ethylthio Thioxanthones such as xanthone 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 photocationic polymerization 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 thereof 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, it is possible to use photoinitiated polymerization assistants such as amines in combination. Examples of the photoinitiator include 2-dimethylaminoethyl benzoate, 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.

  A catalyst can be added to the pressure-sensitive adhesive composition of the present invention. The type of the catalyst is not particularly limited, and a catalyst known in this field such as a tin catalyst can be used, but it is preferable to use a tin catalyst. Moreover, in this invention, it is preferable not to contain the catalyst which uses iron as an active center.

  Examples of the tin catalyst include dioctyltin dilaurate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctate, dibutyltin diolate, diphenyltin diacetate, dibutyltin oxide, dibutyltin dimethoxide, dibutylbis (triethoxysiloxy) tin, dibutyltin benzyl Malate, dioctyltin diacetate, etc. can be mentioned, These can be used individually or in mixture of 2 or more types. Among these, dioctyltin dilaurate is preferable. The amount of the catalyst added is not particularly limited, but is preferably about 0.001 to 0.5 parts by weight with respect to 100 parts by weight of the acrylic polymer, for example.

  Furthermore, the pressure-sensitive adhesive composition of the present invention may contain other known additives, for example, powders such as antistatic agents, colorants, pigments, surfactants, plasticizers, and adhesive properties. Giving agent, 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, particle It can be suitably blended depending on the use of the shape, foil or the like.

  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 composition of the present invention can be suitably used for forming a pressure-sensitive adhesive layer of a carrier film for a transparent conductive film.

2. Pressure-sensitive adhesive layer The pressure-sensitive adhesive layer of the present invention is formed from the pressure-sensitive adhesive composition. Specifically, the pressure-sensitive adhesive layer can be formed by coating the pressure-sensitive adhesive composition on a substrate to form a coating layer and solidifying the coating layer by drying or the like.

  The method for forming the pressure-sensitive adhesive layer on the base material (or a support described later) is not particularly limited. For example, the pressure-sensitive adhesive composition is applied to the base material (for example, 20 wt. % Or more, more preferably 30% by weight or more), and the polymerization solvent and the like are removed by drying to form an adhesive layer on the substrate. Thereafter, curing may be performed for the purpose of adjusting the component transfer of the pressure-sensitive adhesive layer, adjusting the crosslinking reaction, and the like. When applying the pressure-sensitive adhesive composition, one or more solvents other than the polymerization solvent may be newly added to the pressure-sensitive adhesive composition.

  Moreover, when producing the carrier film for transparent conductive films mentioned later, the said adhesive composition can be apply | coated directly on the support body of the said carrier film, and an adhesive layer can be produced.

  Moreover, as a coating method of the said adhesive composition, the well-known method used for manufacture of an adhesive tape etc. is used. Specifically, for example, roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating and the like can be mentioned.

  The substrate is not particularly limited, and examples thereof include various substrates such as a transparent resin substrate and a release film.

  The transparent resin substrate is not particularly limited, and various resin films having transparency are used. The resin film is formed of a single layer film. 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.

  The thickness of the transparent resin base material is preferably 15 to 200 μm.

  In addition, examples of the constituent material of the release film include those similar to the transparent resin base material. Further, if necessary, a release material of silicone type, fluorine type, long chain alkyl type or fatty acid amide type may be used. It is also possible to carry out antistatic treatment such as mold release, antifouling treatment with silica powder or the like, coating type, kneading type, vapor deposition type. In particular, the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the release film.

  The thickness of the release film is usually 5 to 200 μm, preferably about 5 to 100 μm.

  The drying conditions for drying the pressure-sensitive adhesive composition applied to the substrate 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 80 to 200 ° C. for about 10 seconds to 30 minutes.

Moreover, when the photoinitiator which is an arbitrary component as mentioned above is mix | blended, after apply | coating to the single side | surface or both surfaces of a base material, an adhesive layer can be obtained by light irradiation. 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 .

  5-50 micrometers is preferable and, as for the thickness of the adhesive layer of this invention, 10-30 micrometers is more preferable. Within the above range, the balance between adhesion and removability is excellent and a preferred embodiment is obtained. The pressure-sensitive adhesive layer of the present invention is formed on the substrate and has a film shape, a sheet shape, a tape shape or the like.

3. Carrier film for transparent conductive film The carrier film for transparent conductive film of the present invention has the pressure-sensitive adhesive layer on at least one side of a support.

  As a method for forming the pressure-sensitive adhesive layer on the support, for example, as described above, the pressure-sensitive adhesive composition can be directly applied on the support to form the pressure-sensitive adhesive layer, and the release film or the like. The pressure-sensitive adhesive layer formed on the substrate can be transferred onto the support.

  Hereinafter, the carrier film for transparent conductive film of the present invention will be described with reference to FIGS. However, the present invention is not limited to the embodiment of FIGS.

  As shown in FIG. 1, the carrier film 3 for transparent conductive film of the present invention has a pressure-sensitive adhesive layer 1 on at least one surface of a support 2, and the surface of the pressure-sensitive adhesive layer 1 that contacts the support 2. It has an adhesive surface A on the opposite side. As shown in FIG. 2, the adhesive surface A is a surface that is in contact with the surface of the transparent substrate 5 constituting the transparent conductive film (the side where the transparent conductive layer 4 of the transparent substrate 5 does not exist).

  As shown in FIG. 3, when the transparent conductive film as the adherend is a transparent conductive film 8 with a functional layer having a functional layer, the adhesive surface A is in contact with the functional layer 7. In addition, the laminated body 9 of this invention mentioned later contains the carrier film 3 for transparent conductive films, and the transparent conductive film 6 (or transparent conductive film 8 with a functional layer) as shown in FIG.

  The carrier film for transparent conductive film of the present invention is heated at 140 ° C. for 90 minutes in a state where the pressure-sensitive adhesive layer of the carrier film is bonded to an adherend, and then the carrier film is pulled from the adherend at a tensile rate of 0. The adhesive strength P when peeled at 3 m / min is preferably 0.7 N / 50 mm or less, more preferably 0.6 N / 50 mm or less, and further preferably 0.5 N / 50 mm or less. . The lower limit value of the adhesive strength P is not particularly limited, but is preferably 0.1 N / 50 mm or more from the viewpoint of the adhesive strength with respect to the transparent conductive film as the adherend. It is preferable that the adhesive force when peeled at a tensile speed of 0.3 m / min is in the above range because the balance between adhesion and removability is excellent.

  The carrier film for transparent conductive film of the present invention is heated at 140 ° C. for 90 minutes in a state where the pressure-sensitive adhesive layer of the carrier film is bonded to an adherend, and then the carrier film is pulled from the adherend at a tensile speed of 10 m. The adhesive strength Q when peeled at / min is preferably 0.7 N / 50 mm or less, more preferably 0.6 N / 50 mm or less, and further preferably 0.5 N / 50 mm or less. The lower limit value of the adhesive strength Q is not particularly limited, but is preferably 0.1 N / 50 mm or more from the viewpoint of the adhesive strength with respect to the transparent conductive film as the adherend. When the adhesive strength when peeled at a tensile speed of 10 m / min exceeds 0.7 N / 50 mm, workability deteriorates, and when the carrier film for transparent conductive film is peeled from the transparent conductive film, the film breaks. This is not preferable because breakage may occur. On the other hand, since the adhesive force when peeled at a tensile speed of 10 m / min is in the above range, even when the carrier film for transparent conductive film is peeled off from the transparent conductive film at high speed, adhesion and re-peelability are improved. It is preferable because of its excellent balance.

  The absolute value of the difference between the adhesive force P and the adhesive force Q is preferably 0.2 N / 50 mm or less, more preferably 0.15 N / 50 mm or less, and 0.1 N / 50 mm or less. More preferably, it is particularly preferably 0.05 N / 50 mm or less. The lower limit of the absolute value of the difference between the adhesive force P and the adhesive force Q is not particularly limited, and the smaller the smaller the better, the more ideally there is no difference (0 N / 50 mm). . If the absolute value of the difference between the adhesive strength P and the adhesive strength Q exceeds 0.2 N / 50 mm, the film may be broken during the peeling or transparent when the carrier film for transparent conductive film is peeled off from the transparent conductive film. A crack may enter the conductive layer. On the other hand, the absolute value of the difference between the adhesive force P and the adhesive force Q is within the above range, so that the peeling is performed like a manual peeling operation (usually peeling at low speed at the beginning and gradually approaching high speed peeling). Even in the case where the speed is not constant, the film is not broken during the peeling or the transparent conductive layer is cracked, and therefore, the releasability of the carrier film for transparent conductive film is excellent, which is preferable.

  The “adhered body” at the time of measuring the adhesive force is a transparent conductive film, and when the transparent conductive film does not have a functional layer, the adherend surface is a transparent substrate constituting the transparent conductive film. When the transparent conductive film has a functional layer, the adherend surface is the surface of the functional layer.

  Although it does not restrict | limit especially as a support body (base material) (2 in FIG. 1) which comprises the carrier film for transparent conductive films of this invention, For example, paper-type support bodies, such as paper; Cloth, a nonwoven fabric, a net, etc. Fiber-based support (the raw material is not particularly limited; for example, Manila hemp, rayon, polyester, pulp fiber, etc. can be selected as appropriate); metal-based support such as metal foil and metal plate; plastic film Plastic support such as rubber sheet; Rubber support such as rubber sheet; Foam such as foam sheet; and laminates thereof (for example, laminates of plastic support and other supports, plastic films, etc. A suitable thin leaf body such as a laminate of (or sheets) can be used.

  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); polycarbonate resins; polyvinyl chloride (PVC); vinyl acetate resins; polyphenylene sulfide (PPS) Amide resins such as polyamide (nylon) and wholly aromatic polyamide (aramid); polyimide resins; polyolefin resins having a cyclic or norbornene structure; polyetheretherketone (PEEK) That. These materials can be used alone or in combination of two or more. Among these, the polyester-based resin has toughness, workability, transparency, and the like, and therefore, by using it as a carrier film for a transparent conductive film, workability and testability are improved. This is a more preferable embodiment.

  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.). In particular, in the present invention, since it is used as a carrier film for a transparent conductive film, polyethylene terephthalate is preferably used as a support. By using polyethylene terephthalate, it becomes a carrier film for a transparent conductive film excellent in toughness, workability, and transparency, and workability is improved, which is a preferred embodiment.

  The thickness of the support is generally 25 to 300 μm, preferably 75 to 200 μm, more preferably 80 to 140 μm, and particularly preferably 90 to 130 μm. Within the above range, the transparent conductive film carrier film is attached to a transparent conductive film (with a functional layer) and used to maintain the shape of the transparent conductive film that is flexible and flexible. This is useful because it can prevent the occurrence of defects such as wrinkles and scratches in the processing step and the conveying step.

  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, ultraviolet treatment, coating type, kneading type, vapor deposition type, etc. can also be performed. In particular, when performing antistatic treatment, it is preferable to provide an antistatic layer between the support and the pressure-sensitive adhesive layer.

  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.

  As the pressure-sensitive adhesive layer of the carrier film for transparent conductive film of the present invention, the pressure-sensitive adhesive layer of the present invention can be suitably used.

  The carrier film for transparent conductive film of the present invention is a separator whose surface is treated with a release agent such as silicone, fluorine, long chain alkyl or fatty acid amide for the purpose of protecting the adhesive surface as necessary. Can be pasted together. Examples of the separator include the release film.

4). Laminated body The laminated body 9 of this invention has the transparent conductive film 6 laminated | stacked on the carrier film 3 for transparent conductive films, and the said carrier film 3 for transparent conductive films,
The carrier film for transparent conductive film 3 is a carrier film for transparent conductive film described in the present specification,
The transparent conductive film 6 has a transparent conductive layer 4 and a transparent substrate 5,
The adhesive surface of the adhesive layer 1 of the carrier film 3 for transparent conductive film is bonded to the surface of the transparent substrate 5 opposite to the surface that contacts the transparent conductive layer 4. Regarding the laminated body 9 (for example, FIG. 2).

  Examples of the carrier film 3 for transparent conductive film include the carrier film for transparent conductive film described in the present specification.

  Examples of the transparent conductive film 6 include a film having a transparent conductive layer 4 and a transparent substrate 5 as shown in FIGS.

  Examples of the transparent substrate 5 include a resin film and a substrate made of glass or the like (for example, a sheet-like, film-like, or plate-like substrate (member)). In particular, a resin film can be mentioned. . 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.

  Further, the transparent base material 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 the transparent conductive layer 4 provided thereon. You may make it improve the adhesiveness with respect to the said transparent base materials 5, such as. Further, before the transparent conductive layer 4 is provided, 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, 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, tin oxide containing antimony, or the like is 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 to 300 nm, and more preferably 15 to 100 nm.

  A 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.

  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.

  In addition, as shown in FIG. 3, a functional layer 7 can be provided on the surface of the transparent conductive film 6 on the side where the transparent conductive layer 5 is not provided. Contact with the functional layer 7.

  Examples of the functional layer include an antiglare treatment (AG) layer, an antireflection (AR) layer, a hard coat (HC), and an antiblocking (AB) layer for the purpose of improving visibility.

  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.

  As a material for forming the hard coat (HC) 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, the antireflection layer, and the antiblocking layer can be provided on the hard coat layer. Further, a hard coat layer having an antiglare function, an antireflection function, an antiblocking function, and an oligomer prevention function can be used.

  As the anti-blocking layer, a curable resin layer containing fine particles, a curable resin composition using a coating composition containing two or more components that are phase-separated, or a combination thereof are used. Thus, those having irregularities formed on the surface are preferably used. Examples of the component of the curable resin layer include a thermosetting resin, an ultraviolet curable resin, and an electron beam curable resin. Moreover, as a coating composition containing 2 or more types of components which phase-separate, the composition as described in the international publication 2005/073763 pamphlet can be used suitably, for example. The thickness of the anti-blocking layer is preferably 0.1 to 30 μm.

  When the said transparent conductive film has a functional layer, as a thickness of a transparent conductive film with a functional layer, 210 micrometers or less are preferable and 150 micrometers or less are more preferable. By using the carrier film for transparent conductive film of the present invention (with functional layer) for the transparent conductive film (adhered body) within the above range, even if the transparent conductive film is very thin, its shape It can hold | maintain, generation | occurrence | production of malfunctions, such as a wrinkle and a crack, can be suppressed, and becomes a preferable aspect.

  The transparent conductive film (with a functional layer) 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. By sticking and using the carrier film for transparent conductive films of this invention, a shape can be hold | maintained and generation | occurrence | production of a malfunction can be suppressed and it becomes a preferable aspect.

  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. In addition, the evaluation item in an Example etc. measured as follows. The blending contents are shown in Table 1 and Table 2, and the evaluation results are shown in Table 2.

Production Example 1
(Adjustment of acrylic polymer)
In a four-flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube and a condenser, 85 parts by weight of 2-ethylhexyl acrylate (2EHA), 10 parts by weight of hydroxyethyl methacrylate (HEMA), 4-hydroxybutyl acrylate (4HBA) Charge 5 parts by weight, 0.2 part by weight of 2,2′-azobisisobutyronitrile and 150 parts by weight of ethyl acetate as a polymerization initiator, introduce nitrogen gas while gently stirring, and adjust the liquid temperature in the flask. The polymerization reaction was carried out for about 6 hours while maintaining the temperature at around 60 ° C. to prepare an acrylic polymer (A1) solution (about 40% by weight). The acrylic polymer (A1) had a weight average molecular weight of 640,000 and Tg of −60.2 ° C.

Production Examples 2-8
In Production Example 1, as shown in Table 1, the acrylic polymer (A2) to (A2) to (A) are prepared in the same manner as in Production Example 1 except that the type of monomer used for the preparation of the acrylic polymer and the use ratio thereof are changed. A6), (A11) and (A12) solutions were prepared.

表１中の略記は、それぞれ以下の通りである。
２ＥＨＡ：２−エチルヘキシルアクリレート
ＢＡ：ブチルアクリレート
ＨＥＭＡ：２−ヒドロキシエチルメタリレート
４ＨＢＡ：４−ヒドロキシブチルアクリレート
ＡＡ：アクリル酸

Abbreviations in Table 1 are as follows.
2EHA: 2-ethylhexyl acrylate BA: butyl acrylate HEMA: 2-hydroxyethyl metallate 4HBA: 4-hydroxybutyl acrylate AA: acrylic acid

<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).
Apparatus: HLC-8220GPC, manufactured by Tosoh Corporation Column:
Sample column: TSK guard column Super HZ-H (1) + TSK gel Super HZM-H (2) manufactured by Tosoh Corp. Reference column: TSK gel Super H-RC (1) manufactured by Tosoh Corp. Flow rate: 0.6 ml / 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) of acrylic polymer>
The glass transition temperature (Tg) (° C.) was determined by the following formula using the following literature values as the glass transition temperature Tg _n (° C.) of the homopolymer of each monomer.

Formula: 1 / (Tg + 273) = Σ [Wn / (Tg _n +273)]
(Wherein Tg (° C.) is the glass transition temperature of the copolymer, Wn (−) is the weight fraction of each monomer, Tg _n (° C.) is the glass transition temperature of the homopolymer of each monomer, and n is the Represents the type.)
Butyl acrylate (BA): -55 ° C
2-ethylhexyl acrylate (2EHA): -70 ° C
2-hydroxyethyl metallate (HEMA): 55 ° C.
4-hydroxybutyl acrylate (4HBA): -32 ° C
Acrylic acid (AA): 106 ° C
In addition, as a reference value, “Synthesis / design of acrylic resin and development of new application” (published by Central Management Development Center Publishing Department) was referred.

Example 1
(Adjustment of adhesive solution)
The acrylic polymer (A1) solution (about 40% by weight) obtained in Production Example 1 was diluted to 29% by weight with ethyl acetate, and hexamethylene was added to 100 parts by weight (solid content) of the acrylic polymer in this solution. Add 15 parts by weight of isocyanurate of diisocyanate (trade name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 0.015 part by weight of dioctyltin dilaurate as a tin catalyst, and keep it at around 25 ° C for about 1 minute. Stirring was performed to prepare an acrylic pressure-sensitive adhesive composition.

Examples 2-7, Comparative Examples 1-4
As shown in Table 2, the acrylic pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the type of acrylic polymer, the crosslinking agent constituting the pressure-sensitive adhesive composition, or the blending amount thereof were changed. Produced.

  Using the acrylic pressure-sensitive adhesive compositions obtained in Examples and Comparative Examples, a carrier film for a transparent conductive film was prepared by the following method, and the following evaluation was performed.

(Preparation of carrier film for transparent conductive film)
The acrylic pressure-sensitive adhesive compositions obtained in Examples and Comparative Examples were applied to one side of a polyethylene terephthalate (PET) substrate (thickness 125 μm, support), heated at 150 ° C. for 90 seconds, and thickness 20 μm. The pressure-sensitive adhesive layer was formed. Next, the surface of the pressure-sensitive adhesive layer was bonded with a silicone-treated surface of a PET release liner (thickness 25 μm) that had been subjected to silicone treatment on one side, and stored at 50 ° C. for 1 day to obtain a carrier film for transparent conductive film. Produced. In use, the release liner was removed before use.

<Adhesion measurement>
As an adherend, a transparent conductive film (trade name: V150-OFJ, PET film having a width of 50 mm and a length of 100 mm, fixed to a SUS plate (SUS430BA), has a transparent conductive layer on one side and an anti-surface on the other side. Nitto Denko film having a blocking layer (formed from a coating composition composed of amorphous silica, acrylic monomer, photoinitiator and additives containing less than 5% by weight of 0.8 μm acrylic particles) The pressure-sensitive adhesive layer of the carrier film for transparent conductive film was bonded to the surface of the anti-blocking layer (manufactured by Co., Ltd.) (pressure bonding with a bonding machine: 0.25 MPa, pressure bonding speed 2.0 m / min). Next, after heating at 140 ° C. for 90 minutes and then leaving at room temperature (25 ° C.) for 30 minutes or longer, using a universal tensile tester in the same environment, a peeling speed of 0.3 m / min (low speed peeling), and The carrier film for transparent conductive film was peeled from the transparent conductive film under the conditions of 10 m / min (high speed peeling) and a peeling angle of 180 °, and the peeling force (N / 50 mm) at this time was measured.

<Pot life>
After leaving the acrylic pressure-sensitive adhesive composition obtained in Examples and Comparative Examples at room temperature (25 ° C.) for 5 hours, it was applied to one side of a polyethylene terephthalate (PET) substrate (thickness 125 μm, support), Evaluation was performed according to the following evaluation criteria.
○: Application was possible without problems.
X: The adhesive was hardened and could not be applied, or a lump of adhesive and paste streaks were generated, causing a problem in appearance.

<White unevenness>
When the PET release liner of the carrier film for transparent conductive film is peeled off and the pressure-sensitive adhesive layer is exposed, when the surface of the pressure-sensitive adhesive layer is visually observed under a fluorescent lamp, the portions that appear whitish and the portions that appear blackish are uneven. The presence or absence (whether or not white unevenness was generated) was confirmed and evaluated according to the following evaluation criteria.
◯: White unevenness was not confirmed.
X: White unevenness was confirmed.

表２中、
Ａ１〜Ａ６、Ａ１１、１２は、それぞれ、製造例１〜８で製造された（メタ）アクリル系ポリマーを示す。

In Table 2,
A1 to A6, A11, and 12 represent the (meth) acrylic polymers produced in Production Examples 1 to 8, respectively.

DESCRIPTION OF SYMBOLS 1 Adhesive layer 2 Support body (base material)
DESCRIPTION OF SYMBOLS 3 Carrier film for transparent conductive films 4 Transparent conductive layer 5 Transparent base material 6 Transparent conductive film 7 Functional layer 8 Transparent conductive film with a functional layer 9 Laminate A Adhesive surface

Claims (8)

(Meth) acrylic polymer containing alkyl (meth) acrylate, hydroxyl group-containing monomer A having a glass transition temperature of 50 ° C. or higher as a homopolymer, and hydroxyl group-containing monomer B having a glass transition temperature of less than 50 ° C. as a monomer unit And a crosslinking agent,
The weight ratio of the hydroxyl group-containing monomer A and the hydroxyl group-containing monomer B (hydroxyl group-containing monomer A / hydroxyl group-containing monomer B) is 1 to 10,
The pressure-sensitive adhesive composition, wherein the crosslinking agent is less than 20 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer.   Monomer component in which the total amount of the hydroxyl group-containing monomer A having a glass transition temperature of the homopolymer of 50 ° C. or higher and the hydroxyl group-containing monomer B having a glass transition temperature of less than 50 ° C. of the homopolymer constitutes the (meth) acrylic polymer. The pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive composition is 10 to 30% by weight based on the total amount.   The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the crosslinking agent is an aliphatic polyisocyanate.   The pressure-sensitive adhesive composition according to claim 3, wherein the aliphatic polyisocyanate contains hexamethylene diisocyanate.   The pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive composition is used for forming the pressure-sensitive adhesive layer of a carrier film for a transparent conductive film having a pressure-sensitive adhesive layer on at least one side of a support.   A pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to claim 1.   A carrier film for a transparent conductive film, comprising the pressure-sensitive adhesive layer according to claim 6 on at least one surface of a support. It is a laminated body which has the transparent conductive film laminated | stacked on the carrier film for transparent conductive films of Claim 7, and the said carrier film for transparent conductive films,
The transparent conductive film has a transparent conductive layer and a transparent substrate,
The laminated body characterized by the adhesive surface of the adhesive layer of the said carrier film for transparent conductive films being bonded together on the surface on the opposite side to the surface which contacts the said transparent conductive layer of the said transparent base material.

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