Laminated film, adhesive sheet, and method of using the same

Abstract

The laminated film 10A comprises a base film 11, a resin layer A containing a conductive polymer compound and a binder resin on one surface of the base film 11, and at least one of a pressure-sensitive adhesive layer 12A and a release layer 13 on the opposite surface of the base film 11. In the laminated film 10A, the content of the binder resin in the resin layer A is 45 to 95 mass %, and the dielectric constant of the surface of the resin layer A at a frequency of 1000 Hz is 5.5 or less.

Description

[Technical Field]

[0001] The present invention relates to a laminated film, a pressure-sensitive adhesive sheet, and methods for using the same. [Background technology]

[0002] Polyester films have excellent properties such as mechanical strength, dimensional stability, flatness, heat resistance, chemical resistance, and optical properties, and also have excellent cost performance, so they are used in a variety of applications.

[0003] Polyester films are sometimes used to protect the surfaces of components such as displays and touch panels.

[0004] In recent years, displays where the touch sensor is placed near the OLED, i.e., the OLED and touch sensor integrated type, are becoming mainstream. The integrated type is called by various names such as Y-OCTA (YOUM on-cell touch AMOLED), ToE (touch on encapsulation), or FMLOC (flexible multi-layer on cell touch) depending on the panel manufacturer. Although the integrated type is more difficult to process than the external type where the touch sensor is externally attached to the OLED, it has the advantage of being able to manufacture thinner panels and is expected to reduce process costs.

[0005] On the other hand, from the viewpoint of preventing malfunction of touch panels, polarizing films having an antistatic adhesive layer have been proposed (Patent Document 1). There are also disclosures regarding the relationship between the sensitivity of touch panels and their dielectric constant (Patent Documents 2 and 3). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2018-165389 A [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-205244 [Patent Document 3] JP 2016-216691 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, with the change in panel structure to the above-mentioned integrated type, the conventionally used surface protection film or release film with antistatic properties may have too good conductivity and may cause problems. For example, a surface protection film consisting of a resin layer (antistatic layer), a substrate film, and an adhesive layer can be attached to the screen of an all-in-one image display device (e.g., a smartphone) that combines an OLED and a touch sensor, and the display screen's operational performance can be checked by touching it with a fingertip. In this case, if the surface protection film used has too good a conductivity, it may malfunction. On the other hand, if the conductivity is reduced, problems such as adhesion of foreign matter or peeling electrification may occur during the processing process.

[0008] Therefore, the present invention has been made in consideration of the above-mentioned problems, and its object is to provide a laminated film that is less likely to malfunction and has appropriate conductive properties, for example, for protecting an integrated image display device in which an image display element such as an OLED and a touch sensor are integrated. [Means for solving the problem]

[0009] In view of the above problems, the inventors of the present invention have conducted extensive research and have considered the conductive performance from the operating principle of touch sensors, and have found that the antistatic performance of a surface protective film or a release film can be measured in terms of its dielectric constant. By adjusting the dielectric constant within a specific range in a laminate film having a specific configuration, it is possible to achieve a unique effect of preventing malfunction of the above-mentioned image display device (e.g., a smartphone) that integrates an OLED and a touch sensor, and have thereby completed the present invention. That is, the present invention provides the following aspects [1] to

[33] .

[0010] [1] A substrate film, a resin layer A containing a conductive polymer compound and a binder resin on one surface of the substrate film, and at least one of a pressure-sensitive adhesive layer and a release layer on the opposite surface of the substrate film, A laminated film, wherein the content of the binder resin in the resin layer A is 45 to 95% by mass, and the dielectric constant of the surface of the resin layer A at a frequency of 1000 Hz is 5.5 or less. [2] The laminated film according to the above [1], wherein the substrate film is a polyester film. [3] The laminated film according to [1] or [2] above, wherein the conductive polymer compound comprises a polymer obtained by doping a compound made of thiophene or a thiophene derivative with another anionic compound. [4] The laminated film according to any one of the above [1] to [3], wherein the resin layer A contains one or more compounds selected from polyglycerin and alkylene oxide adducts of polyglycerin, or derivatives thereof. [5] The laminated film according to [4] above, wherein the one or more compounds selected from the group consisting of polyglycerol and alkylene oxide adducts of polyglycerol, or derivatives thereof, are polyglycerols represented by the following general formula (3): [ka] (n is an integer ranging from 2 to 20.) [6] The laminated film according to any one of the above [1] to [5], wherein the content of one or more compounds or derivatives thereof selected from polyglycerin and alkylene oxide adducts of polyglycerin in the resin layer A is 0 to 60 mass %. [7] The laminated film according to any one of the above [1] to [6], wherein the resin layer A does not contain a crosslinking agent. [8] The surface resistivity of either the surface of the resin layer A or the opposite surface is 1 × 10 6 (Ω / □) or more, 5×10 8 The laminated film according to any one of the above [1] to [7], wherein the resistance is (Ω / □) or less. [9] The laminated film according to any one of the above [1] to [8], wherein the resin layer A contains two types of conductive polymer compounds.

[10] The laminated film according to the above [9], wherein the two types of conductive polymer compounds are a polymer obtained by doping a compound made of thiophene or a thiophene derivative with another anionic compound, and a polyaniline compound.

[11] The laminate film according to any one of the above [1] to

[10] , further comprising a resin layer B containing a binder resin on the opposite surface of the base film.

[12] The laminated film according to the above

[11] , wherein the content of the binder resin in the resin layer B is 45 to 95% by mass.

[13] The laminated film according to the above

[11] or

[12] , wherein the resin layer B further contains a conductive polymer compound.

[14] The laminated film according to

[13] above, wherein the conductive polymer compound in the resin layer B comprises a polymer obtained by doping a compound consisting of thiophene or a thiophene derivative with another anionic compound.

[15] The laminated film according to any one of the above

[11] to

[14] , wherein the resin layer B contains one or more compounds selected from polyglycerin and alkylene oxide adducts of polyglycerin, or derivatives thereof.

[16] The laminated film according to

[15] above, wherein the one or more compounds or derivatives thereof selected from polyglycerin and alkylene oxide adducts of polyglycerin in the resin layer B are polyglycerin represented by the following general formula (3): [ka] (n is an integer ranging from 2 to 20.)

[17] The laminated film according to any one of the above

[11] to

[16] , wherein the content of one or more compounds or derivatives thereof selected from polyglycerin and alkylene oxide adducts of polyglycerin in the resin layer B is 0 to 60 mass%.

[18] The laminated film according to any one of the above

[11] to

[17] , wherein the resin layer B does not contain a crosslinking agent.

[19] The laminated film according to any one of the above

[11] to

[18] , wherein the resin layer B contains two types of conductive polymer compounds.

[20] The laminated film according to

[19] above, wherein the two types of conductive polymer compounds in the resin layer B are a polymer obtained by doping a compound made of thiophene or a thiophene derivative with another anionic compound, and a polyaniline compound.

[21] The laminated film according to any one of the above [1] to

[20] , wherein the pressure-sensitive adhesive layer is made of an acrylic, urethane, or silicone pressure-sensitive adhesive.

[22] The laminated film according to any one of the above [1] to

[21] , wherein the pressure-sensitive adhesive layer is made of a pressure-sensitive adhesive that does not have antistatic properties.

[23] The laminate film according to any one of the above [1] to

[22] , which is a release film with an adhesive layer, having the release layer and the adhesive layer in this order on the opposite side of the base film.

[24] The laminated film according to any one of the above

[11] to

[23] , which is a release film with an adhesive layer, having the release layer and the adhesive layer in this order on the resin layer B.

[25] The laminated film according to any one of the above [1] to

[24] , wherein the release layer contains a curable silicone resin.

[26] A method for using the laminated film according to any one of [1] to

[25] above, A method for using a laminate film, the method comprising: attaching the surface of the pressure-sensitive adhesive layer of the laminate film to a surface of an optical member;

[27] A method for using the laminate film according to the above

[26] , wherein the optical member is an image display device in which an OLED and a touch sensor are integrated.

[28] A pressure-sensitive adhesive sheet comprising the laminated film according to any one of the above [1] to

[25] and a second release film attached to the pressure-sensitive adhesive layer of the laminated film.

[29] A method for using the pressure-sensitive adhesive sheet according to

[28] above, A method for using the pressure-sensitive adhesive sheet, comprising peeling off the second release film and then bonding the exposed surface of the pressure-sensitive adhesive layer to the surface of an optical member.

[30] A method for using the pressure-sensitive adhesive sheet according to

[29] above, wherein the optical component is an integrated image display device comprising an OLED and a touch sensor.

[31] The laminate film according to any one of the above [1] to

[25] , which is used to protect an image display device in which an OLED and a touch sensor are integrated.

[32] A release film according to any one of the above [1] to

[25] , wherein the pressure-sensitive adhesive layer is used in an image display device in which an OLED and a touch sensor are integrated, and the release film is for protecting the pressure-sensitive adhesive layer.

[33] The pressure-sensitive adhesive sheet according to

[27] above, which is for attachment to an image display device in which an OLED and a touch sensor are integrated. [Effects of the Invention]

[0011] The laminated film of the present invention exhibits low dielectric constant characteristics even when a general-purpose pressure-sensitive adhesive layer or release layer is provided by setting the dielectric constant of the resin layer A side within a specific range. Therefore, the laminated film can be suitably used, for example, for protecting an image display device in which an OLED and a touch sensor are integrated, or for protecting a pressure-sensitive adhesive layer that bonds members mounted on the integrated image display device. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view showing a laminated film according to a first embodiment. [Figure 2] FIG. 4 is a schematic cross-sectional view showing a laminated film according to a second embodiment. [Figure 3] FIG. 1 is a schematic cross-sectional view showing an example of an integrated image display device. [Figure 4] 10A and 10B are schematic cross-sectional views showing a step in a manufacturing method of an integrated image display device. [Figure 5] 10A and 10B are schematic cross-sectional views showing a step in a manufacturing method of an integrated image display device. [Figure 6] 10A and 10B are schematic cross-sectional views showing a step in a manufacturing method of an integrated image display device. DETAILED DESCRIPTION OF THE INVENTION

[0013] An example of an embodiment of the present invention will be described in detail below. However, the present invention is not limited to the embodiment described below, and can be implemented by modifying it as desired within the scope of the gist of the present invention.

[0014] <<<Laminated film>>> The laminated film of the present invention is characterized by comprising a base film, a resin layer A containing a conductive polymer compound and a binder resin on one surface of the base film, and at least one of a pressure-sensitive adhesive layer and a release layer on the opposite surface of the base film, wherein the content of the binder resin in the resin layer A is 45 to 95 mass %, and the dielectric constant of the surface of the resin layer A at a frequency of 1000 Hz is 5.5 or less.

[0015] <<Base film>> The material of the base film is not particularly limited as long as it is in the form of a film. For example, it may be made of paper, resin, metal, etc. Among these, resin is preferred from the viewpoint of mechanical strength and flexibility. Examples of resin substrate films include films formed from polymers such as polyethylene, polypropylene, polyester, polystyrene, polycarbonate, polyethersulfone, polyamide, polyimide, etc. Furthermore, as long as they can be formed into a film, they may be mixtures of these materials (i.e., polymer blends) or composites of structural units (e.g., copolymers). Among the films exemplified above, polyester films are particularly preferred because of their excellent physical properties such as heat resistance, flatness, optical properties, strength, etc. Hereinafter, a detailed explanation will be given using an example in which the base film is a polyester film, but resin films other than polyester films have the same configuration as polyester films except for the resin, and therefore explanations thereof will be omitted.

[0016] <<Polyester film>> The polyester film used as the substrate film may have a single-layer structure or a multi-layer structure. In the case of a multi-layer structure, it may have a two-layer structure, a three-layer structure, or may have four or more layers without departing from the gist of the present invention, and the number of layers is not particularly limited. The polyester film may be unstretched, uniaxially stretched, or biaxially stretched, but a biaxially stretched polyester film is preferred from the viewpoints of thinning and dimensional stability.

[0017] The polyester used in the polyester film may be a homopolyester or a copolymer polyester. In the case of homopolyesters, those obtained by polycondensation of aromatic dicarboxylic acids and aliphatic glycols are preferred. Examples of aromatic dicarboxylic acids include terephthalic acid and naphthalenedicarboxylic acids such as 2,6-naphthalenedicarboxylic acid, and examples of aliphatic glycols include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. A typical example of a polyester is polyethylene terephthalate. On the other hand, examples of the dicarboxylic acid component of the copolymer polyester include one or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid. Examples of the glycol component include one or more of propylene glycols such as ethylene glycol, diethylene glycol, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2,2-isopropyl-1,3-propanediol, and 2,2-di-n-1,3-propanediol, butanediol, 1,4-cyclohexanedimethanol, hexanediol, and neopentyl glycol.

[0018] The intrinsic viscosity of the polyester is not particularly limited, but is preferably 0.5 to 1 dL / g, more preferably 0.53 to 0.9 dL / g, even more preferably 0.56 to 0.80 dL / g, and even more preferably 0.6 to 0.75 dL / g.

[0019] The polyester polymerization catalyst is not particularly limited, and any conventionally known compound can be used, such as a titanium compound, a germanium compound, an antimony compound, a manganese compound, an aluminum compound, a magnesium compound, and a calcium compound.

[0020] As will be described later, polyester films are suitable for, for example, protective films, but depending on the conditions of various processes, oligomer components may precipitate from the polyester film upon heating, causing contamination of the product. In order to suppress the amount of oligomer component precipitation, the film may be produced using a polyester with a low oligomer component content as the raw material. Various known methods can be used to produce polyester with a low oligomer component content, such as a method of solid-phase polymerization after polyester production. The amount of oligomer component precipitation may also be suppressed by forming a polyester film with three or more layers, with the outermost layer (surface layer) of the polyester film being a layer made from a polyester raw material with a low oligomer component content. The polyester may also be obtained by esterification or transesterification, followed by melt polycondensation under reduced pressure at a higher reaction temperature.

[0021] The polyester film may contain an ultraviolet absorber in order to improve the weather resistance of the film and prevent deterioration of the adherend, etc. The ultraviolet absorber is a compound that absorbs ultraviolet light and is not particularly limited as long as it can withstand the heat applied in the polyester film production process.

[0022] The ultraviolet absorber includes organic ultraviolet absorbers and inorganic ultraviolet absorbers, and organic ultraviolet absorbers are preferred from the viewpoint of transparency.The organic ultraviolet absorbers are not particularly limited, but examples thereof include cyclic iminoesters, benzotriazoles, and benzophenones.From the viewpoint of durability, cyclic iminoesters and benzotriazoles are more preferred.In addition, two or more types of ultraviolet absorbers can be used in combination.

[0023] The polyester film may be designed without incorporating particles to improve transparency, or may be designed with particles incorporated primarily for the purposes of imparting lubricity and preventing scratches during each process. When particles are incorporated, the type of particles is not particularly limited as long as they are capable of imparting lubricity. Specific examples include inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenolic resin, epoxy resin, and benzoguanamine resin. Furthermore, precipitated particles obtained by precipitating and finely dispersing a portion of a metal compound such as a catalyst during the polyester production process can also be used.

[0024] When particles are blended, there is no particular limitation on their shape, and any of spherical, blocky, rod-like, flat, etc. may be used. There are also no particular limitations on their hardness, specific gravity, color, etc. Two or more types of these particles may be used in combination as needed.

[0025] When particles are incorporated, the average particle size is usually 5 μm or less, preferably 0.01 to 4 μm, preferably 0.1 to 3.5 μm, and more preferably 0.5 to 3 μm. A particle size of 5 μm or less is preferred because it prevents the film surface from becoming too rough and is less likely to cause problems when various surface functional layers are formed in subsequent processes. Furthermore, a particle size of 0.01 μm or more is preferred because it provides a necessary and sufficient effect. The average particle size can be measured, for example, by observing the polyester film using a TEM and averaging the particle sizes of 10 particles.

[0026] Furthermore, the particle content in the polyester film is usually less than 5% by mass, preferably less than 3% by mass. When the particle content is less than 5% by mass, the transparency of the film is easily ensured. The lower limit of the particle content is usually 0.01% by mass, preferably 0.1% by mass. When the polyester film has a single layer structure and particles are to be contained, the particles may be contained in the single layer in the above particle content. When particles are contained, for example, it is preferable to provide a surface layer and an intermediate layer and contain particles in the surface layer. In this case, it is more preferable to have a multilayer structure having a particle-containing surface layer, an intermediate layer, and a particle-containing surface layer in this order. In the case of a multilayer structure, it is preferable that the particle content in the surface layer is within the above-mentioned particle content range. Therefore, it is preferable that the particle content in the surface of the polyester film is within the above-mentioned range.

[0027] The method for incorporating particles into a polyester film is not particularly limited, and any conventionally known method can be adopted. For example, in the case of a multi-layer polyester film, the particles can be incorporated at any stage in the production of the polyester constituting each layer, but it is preferable to incorporate the particles after the completion of the esterification or transesterification reaction.

[0028] In addition to the above-mentioned ultraviolet absorbers and particles, conventionally known antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments, etc. may be blended into the polyester film as needed. These preferably do not contain fluorine components.

[0029] The thickness of the polyester film is not particularly limited as long as it can be formed into a film, but is usually in the range of 10 to 350 μm, preferably 25 to 250 μm, more preferably 38 to 125 μm, and even more preferably 40 to 100 μm.

[0030] The haze of the polyester film is not particularly limited, but is preferably 8% or less, more preferably 5% or less, even more preferably 3% or less, even more preferably 2% or less, and particularly preferably 1.5% or less. The lower limit is not particularly limited, but may be, for example, 0.01%, or may be 0.1%.

[0031] Next, specific examples of polyester film production will be described, but the present invention is not limited to these examples. For example, when producing a biaxially stretched polyester film, a preferred method is to extrude dried pellets of the polyester raw material described above from a die using an extruder as a molten sheet, and then cool and solidify the molten sheet on a cooling roll such as a rotating cooling drum to obtain an unstretched sheet. In this case, it is preferable to increase the adhesion between the sheet and the rotating cooling drum to improve the flatness of the sheet, and an electrostatic adhesion method and / or a liquid application adhesion method are preferably used. The unstretched sheet is then biaxially stretched. In this case, the unstretched sheet is first stretched in one direction using a roll or tenter-type stretching machine. The stretching temperature is usually 70 to 120°C, preferably 80 to 110°C, and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Next, the sheet is stretched in a direction perpendicular to the first-stage stretching direction, at a stretching temperature of usually 70 to 170°C, and a stretching ratio of usually 3.0 to 7 times, preferably 3.5 to 6 times. Subsequently, the film is heat-treated under tension or relaxation of 30% or less at a temperature of 180 to 270°C to obtain a biaxially oriented film. The stretching may be performed in one direction in two or more stages. In this case, it is preferable to perform the stretching so that the final stretch ratios in both directions are within the above ranges.

[0032] A simultaneous biaxial stretching method can also be used to produce polyester films. In the simultaneous biaxial stretching method, the unstretched sheet is simultaneously stretched and oriented in the machine direction (longitudinal direction) and width direction (transverse direction) under temperature control, typically at 70 to 120°C, and preferably at 80 to 110°C, with the area stretching ratio being typically 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times. Subsequently, the film is subjected to a heat treatment under tension or relaxation of 30% or less at a temperature of typically 170 to 250°C to obtain a stretched and oriented film. Regarding the simultaneous biaxial stretching device employing the above-mentioned stretching method, any conventionally known stretching method such as a screw method, a pantograph method, or a linear drive method can be employed.

[0033] <<Resin layer>> (Resin layer A) The laminated film of the present invention has a resin layer A formed from a resin composition A on one surface of a base film. The resin layer A may be formed directly on a base film such as a polyester film, or another layer may be provided between the base film such as a polyester film and the resin layer A. It is an essential requirement that the resin layer A of the base film of the present invention contains a conductive polymer compound and a binder resin.

[0034] Resin layer A, i.e., resin composition A, contains a conductive polymer compound and a binder resin as essential components, and may also contain a polyglycerin-based compound described below, and more preferably contains a conductive polymer compound, a polyglycerin-based compound, and a binder resin. It can be assumed that resin layer A contains unreacted compounds of the various compounds in resin composition A, reacted compounds, or a mixture thereof.

[0035] ((Conductive polymer compound)) A conductive polymer compound is contained in the resin layer A to exhibit low dielectric constant characteristics. This conductive polymer compound is suitable from the viewpoint of recent PFAS regulations, as it can be made into a composition that does not contain fluorine components.

[0036] Examples of conductive polymer compounds include polymers (hereinafter also referred to as "thiophene-based compounds") obtained by doping a compound made of thiophene or a thiophene derivative with another anionic compound. Examples of thiophene-based compounds include those obtained by polymerizing a compound of the following formula (1) or (2) in the presence of a polyanion. The above-mentioned thiophene-based compounds may also be used in combination with a different polymer having a thiophene skeleton.

[0037] [ka]

[0038] In the above formula (1), R1 and R 2 are each independently hydrogen or a hydrocarbon group having 1 to 20 carbon atoms. Examples of the hydrocarbon group include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.

[0039] [ka]

[0040] In the above formula (2), n represents an integer of 1 to 4.

[0041] Examples of polyanions used in polymerizing the polymer include poly(meth)acrylic acid, polymaleic acid, polystyrene sulfonic acid, polyvinyl sulfonic acid, etc. As a method for producing such a polymer, for example, a method such as that disclosed in JP-A-7-90060 can be used. As the thiophene-based compound, a compound of the above formula (2) in which n is 2 and in which polystyrene sulfonic acid is used as the polyanion is preferably used.

[0042] When these polyanions are acidic, they may be partially or completely neutralized. Preferred bases for neutralization include ammonia, organic amines, and alkali metal hydroxides.

[0043] Furthermore, the conductive polymer compound may be a compound other than a thiophene-based compound, for example, a polyaniline compound. The polyaniline compound used is one having a polyaniline skeleton, and preferably has a main repeating unit of an alkoxy-substituted aminobenzenesulfonic acid, which has electrical conductivity. The alkoxy group is not particularly limited as long as it is a lower alkoxy group, but a methoxy group is preferred in terms of cost and performance. In the present invention, it is preferable that substantially all of the aromatic rings in the polyaniline skeleton contain a sulfonic acid group and an alkoxy group, but there is no particular limitation as long as the polyaniline skeleton lacks one or both of the substituents or has another substituent. The number average molecular weight of the polyaniline compound, whose main repeating unit is an alkoxy-substituted aminobenzenesulfonic acid and has conductivity, is not particularly limited, but is preferably 5,000 to 20,000. A number average molecular weight of 5,000 or more is advantageous for constructing a conductive network. On the other hand, a number average molecular weight of 20,000 or less prevents the viscosity from becoming too high, resulting in good coatability. The number average molecular weight of the polyaniline compound is measured by gel permeation chromatography (GPC).

[0044] The polyaniline compound having an alkoxy-substituted aminobenzenesulfonic acid as the main repeating unit and having electrical conductivity is generally highly acidic, and therefore can be used by adjusting the pH with a basic compound, which is preferable. The basic compound is preferably ammonia or an organic amine, and more preferably ammonia.

[0045] In the present invention, in order to adjust the dielectric constant of the resin layer, two or more different types of conductive polymer compounds may be used in combination. For example, a combination of a thiophene compound and a polyaniline compound may be used. By adjusting the blending ratio of the two, it is possible to easily adjust the dielectric constant to a desired range.

[0046] (binder resin) Resin layer A, i.e., resin layer composition A, contains a binder resin. By containing a binder resin, resin layer A can be provided with film-forming properties. In addition, coating appearance, transparency, etc. can also be improved. The binder resin is preferably a polymer compound having a number average molecular weight (Mn) of 1000 or more as measured by gel permeation chromatography (GPC). Various conventionally known polymers, such as polyester resins, acrylic resins, and urethane resins, can be used as the binder resin. These may be used alone or in combination of two or more. Among these binder resins, it is preferable to use urethane resins from the viewpoint of coating appearance, and urethane acrylate resins are particularly preferable. These binder resins can also be used as binder resins for resin layer B, which will be described later. When used as binder resins for resin layer B, the use of urethane resins, particularly urethane acrylate resins, can also improve adhesion to the pressure-sensitive adhesive layer.

[0047] The urethane resin contained in the resin layer A is a polymeric compound having a urethane bond in the molecule, and is usually produced by the reaction of a polyol with an isocyanate. Examples of polyols include polycarbonate polyols, polyester polyols, polyether polyols, polyolefin polyols, and acrylic polyols. These compounds may be used alone or in combination. Among these, polycarbonate polyols, polyester polyols, and polyether polyols are preferred, with polycarbonate polyols and polyester polyols being more preferred. It is also preferable to use at least one of these in combination with an acrylic polyol. The use of an acrylic polyol can produce a urethane acrylate resin.

[0048] Polycarbonate polyols are obtained by dealcoholization reaction of polyhydric alcohols and carbonate compounds. Examples of polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, trimethylolpropane, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 3,3-dimethylolheptane. Examples of carbonate compounds include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and ethylene carbonate, and examples of polycarbonate polyols obtained by the reaction of these compounds include poly(1,6-hexylene) carbonate and poly(3-methyl-1,5-pentylene) carbonate.

[0049] Examples of polyester polyols include polycarboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.) or their acid anhydrides and polyhydric alcohols (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2 2-methyl-2-propyl-1,3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2-hexyl-1,3-propanediol, cyclohexanediol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyldialkanolamine, lactonediol, etc.), and those having derivative units of lactone compounds such as polycaprolactone.

[0050] Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, and polyhexamethylene ether glycol.

[0051] Examples of acrylic polyols include compounds having two or more hydroxyl groups and one or more (meth)acrylate groups. Specific examples include trimethylolpropane-based acrylates such as trimethylolpropane mono(meth)acrylate, ditrimethylolpropane-based acrylates such as ditrimethylolpropane mono(meth)acrylate, ditrimethylolpropane di(meth)acrylate, and ditrimethylolpropane tri(meth)acrylate, pentaerythritol-based acrylates such as pentaerythritol mono(meth)acrylate, pentaerythritol di(meth)acrylate, and pentaerythritol tri(meth)acrylate, dipentaerythritol-based acrylates such as dipentaerythritol mono(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, and dipentaerythritol tetra(meth)acrylate, tripentaerythritol-based acrylates, and tetrapentaerythritol (meth)acrylate, etc.

[0052] Examples of polyisocyanates constituting the urethane resin include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, and tolidine diisocyanate; aliphatic diisocyanates having an aromatic ring such as α,α,α',α'-tetramethylxylylene diisocyanate; methylene diisocyanate; propylene diisocyanate; and lysine diisocyanate. Examples of suitable isocyanates include aliphatic diisocyanates such as trimethylhexamethylene diisocyanate and hexamethylene diisocyanate, and alicyclic diisocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylenebis(4-cyclohexyl isocyanate), dicyclohexylmethane diisocyanate, isopropylidenedicyclohexyl diisocyanate, and hydrogenated xylylene diisocyanate. These may be used alone or in combination, and these polyisocyanate compounds may be dimers, trimers such as those with isocyanuric rings, or polymers of higher order. Furthermore, among the above-mentioned isocyanates, aliphatic or alicyclic isocyanates are more preferred than aromatic isocyanates in terms of improving adhesion to active energy ray-curable coating materials and preventing yellowing due to ultraviolet rays.

[0053] A chain extender may be used when synthesizing the urethane resin. There are no particular restrictions on the chain extender as long as it has two or more active groups that react with isocyanate groups, and generally, chain extenders having two hydroxyl groups or two amino groups can be mainly used.

[0054] Examples of chain extenders having two hydroxyl groups include glycols such as aliphatic glycols such as ethylene glycol, propylene glycol, butanediol, and pentanediol; aromatic glycols such as xylylene glycol and bishydroxyethoxybenzene; and ester glycols such as neopentyl glycol and neopentyl glycol hydroxypivalate. Examples of chain extenders having two amino groups include aromatic diamines such as tolylenediamine, xylylenediamine, and diphenylmethanediamine; aliphatic diamines such as ethylenediamine, propylenediamine, hexanediamine, 2,2-dimethyl-1,3-propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, and 1,10-decanediamine; and alicyclic diamines such as 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isopropyltrimoniumcyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, 1,3-bisaminomethylcyclohexane, and isophoronediamine.

[0055] The urethane resin contained in the resin layer A may be a solvent-borne resin, but is preferably a water-borne resin. To disperse or dissolve the urethane resin in water, there are various methods, such as a forced emulsification type using an emulsifier, a self-emulsification type in which hydrophilic groups are introduced into the urethane resin, or a water-soluble type. In particular, a self-emulsification type in which ionic groups are introduced into the urethane resin skeleton to form an ionomer is preferred, as it provides excellent storage stability of the liquid and excellent water resistance, transparency, and adhesion of the resulting coating layer. The ionic group to be introduced may be a carboxyl group, sulfonic acid, phosphoric acid, phosphonic acid, quaternary ammonium salt, or the like, but a carboxyl group is preferred. Various methods can be used to introduce a carboxyl group into a urethane resin at each stage of the polymerization reaction. For example, a resin containing a carboxyl group may be used as a copolymerization component during prepolymer synthesis, or a component containing a carboxyl group may be used as a component of a polyol, polyisocyanate, chain extender, or the like. A preferred method involves using a carboxyl group-containing diol and introducing the desired amount of carboxyl groups by adjusting the amount of this component charged. For example, dimethylolpropionic acid, dimethylolbutanoic acid, bis-(2-hydroxyethyl)propionic acid, bis-(2-hydroxyethyl)butanoic acid, or the like can be copolymerized with the diol used in the polymerization of the urethane resin. Furthermore, the carboxyl group is preferably neutralized with ammonia, amines, alkali metals, inorganic alkalis, or the like to form a salt. Ammonia, trimethylamine, and triethylamine are particularly preferred. From the viewpoint of improving adhesion, the urethane resin is preferably a urethane resin containing a carbon-carbon double bond, more preferably a polycarbonate polyol or a polyester polyol, and a urethane resin containing a carbon-carbon double bond, and particularly preferably a polycarbonate polyol, and a urethane resin containing a carbon-carbon double bond.

[0056] The carbon-carbon double bond-containing urethane resin is a urethane resin having a carbon-carbon double bond therein, and conventionally known materials can be used. For example, the carbon-carbon double bond may be introduced into the urethane resin in the form of an acrylate group, a methacrylate group, a vinyl group, an allyl group, or the like.

[0057] Various substituents can be introduced into the carbon-carbon double bond, and may include, for example, alkyl groups such as methyl and ethyl groups, phenyl groups, halogen groups, ester groups, amide groups, or structures such as conjugated double bonds. The number of substituents is not particularly limited, and mono-, di-, tri-, or tetra-substituted compounds can be used, with mono- or di-substituted compounds being preferred in terms of reactivity, and mono-substituted compounds being even more preferred.

[0058] From the viewpoint of ease of introduction into the urethane resin and adhesion to the pressure-sensitive adhesive layer, an acrylate group or a methacrylate group is preferred, an acrylate group or a methacrylate group without a substituent is more preferred, and an acrylate group without a substituent is particularly preferred. As the urethane resin into which an acrylate group or a methacrylate group has been introduced, the above-mentioned urethane acrylate resin is preferred.

[0059] ((Polyglycerin-based compounds)) In order to improve film-forming properties and antistatic properties, the resin layer A preferably contains one or more compounds selected from polyglycerin and alkylene oxide adducts of polyglycerin or derivatives thereof (hereinafter also referred to as "polyglycerin-based compounds"). Polyglycerin is a compound represented by the following general formula (3):

[0060] [ka]

[0061] In the above formula (3), n is usually in the range of 2 to 20, preferably 2 to 15, more preferably 2 to 10, and even more preferably 2 to 7. By using a compound in this range, it becomes easier to obtain good coating appearance, antistatic properties, durability of the resin layer, etc.

[0062] The alkylene oxide adduct of polyglycerin has a structure in which alkylene oxide is addition polymerized to the hydroxyl group of polyglycerin represented by the general formula (3).

[0063] Here, the structure of the alkylene oxide added to each hydroxyl group in the polyglycerol skeleton may be different, and it is sufficient that the alkylene oxide is added to at least one hydroxyl group in the molecule, and it is not necessary that the alkylene oxide or its derivative is added to all hydroxyl groups.

[0064] The alkylene oxide added to polyglycerol is preferably ethylene oxide or propylene oxide. Of these, ethylene oxide is preferred. The number of added alkylene oxides is preferably such that the number average molecular weight of the final compound is in the range of 200 to 5,000. By keeping the alkylene chain of the alkylene oxide at a certain length or less, it is possible to prevent the hydrophobicity from becoming too strong and the dispersibility in the coating liquid from deteriorating, and the antistatic properties and transparency of the resin layer A tend to be less likely to decrease, so it is advisable to adjust the chain length taking this into consideration.

[0065] Examples of derivatives of polyglycerin or alkylene oxide adducts of polyglycerin include ether-type compounds such as oxyethylene alkyl ethers, oxyethylene alkylphenyl ethers, oxyethylene sterol ethers, oxyethylene lanolin derivatives, ethylene oxide derivatives of alkylphenol-formalin condensates, polyoxyethylene oxypropylene block copolymers, oxyethylene oxypropylene random copolymers, and oxyethylene oxypropylene alkyl ethers, and ether ester-type compounds such as oxyethylene glycerin fatty acid esters, oxyethylene sorbitan fatty acid esters, oxyethylene sorbitol fatty acid esters, and ethylene glycol fatty acid esters, and compounds in which the like are added to polyglycerin or polyglycerin. The polyglycerol, the alkylene oxide adduct of polyglycerol, or the derivatives thereof may be used alone or in combination of two or more kinds.

[0066] <Composition ratio of resin layer A> The content of the conductive polymer compound in the resin layer A is preferably 1 to 20 mass%, more preferably 1 to 18 mass%, even more preferably 1 to 16 mass%, and even more preferably 4 to 16 mass%. When the content is within this range, the desired range of low dielectric constant characteristics tends to be easily achieved.

[0067] A polyaniline compound may be used as the conductive polymer compound. In this case, the content of the polyaniline compound in the resin layer A is preferably in the range of 0.1 to 15% by mass, more preferably 0.3 to 10% by mass, and even more preferably 0.5 to 7% by mass. By setting the content to 0.1% by mass or more, the dielectric constant can be adjusted to the desired range. Furthermore, by setting the content to 15% by mass or less, sufficient water resistance can be obtained.

[0068] When a polyaniline compound is used, it may be used in combination with a thiophene compound, as described above. In this case, the content of the thiophene compound in the resin layer A is preferably in the range of 0.1 to 15% by mass, more preferably 0.3 to 7% by mass, and even more preferably 0.5 to 3% by mass. By setting the content within the above range, it is easy to adjust the dielectric constant to the desired range.

[0069] The content of the polyglycerin-based compound in the resin layer A is, for example, in the range of 0 to 60% by mass, preferably 0 to 50% by mass, more preferably 0 to 40% by mass, and even more preferably 0 to 35% by mass. When the content is in this range, the desired range of low dielectric constant characteristics tends to be easily achieved. Note that a content of 0% by mass means that the resin layer A (i.e., the resin composition A) does not contain a polyglycerin-based compound. Furthermore, when the resin layer A contains a polyglycerin-based compound, from the viewpoint of properly exerting the effect of using the polyglycerin-based compound, the content of the polyglycerin-based compound is, for example, 1 to 60 mass%, preferably 5 to 50 mass%, more preferably 10 to 40 mass%, and even more preferably 15 to 35 mass%.

[0070] The content of the binder resin in the resin layer A is 45 to 95% by mass. If the content of the binder resin is less than 45% by mass, the dielectric constant tends to be high, making it difficult to ensure low dielectric constant characteristics. On the other hand, if the content is more than 95% by mass, it becomes difficult to incorporate an appropriate amount of the conductive polymer compound, making it impossible to ensure appropriate conductive characteristics, and the antistatic performance may decrease. It may also be difficult to achieve good transparency. The content of the binder resin in the resin layer A is more preferably 60 to 95% by mass, and even more preferably 70 to 94% by mass. The content of the resin layer B described later is also as described above, but in the case of the resin layer B, by making it equal to or greater than the above lower limit, it becomes easier to ensure low dielectric constant characteristics and also to improve the adhesion of the resin layer B to the adhesive layer and release layer.

[0071] When the resin layer A contains a polyglycerin-based compound, the ratio of the content of the polyglycerin-based compound in the resin layer A to the content of the conductive polymer compound in the resin layer A (content of the polyglycerin-based compound / content of the conductive polymer compound) is preferably 2.2 to 7, more preferably 2.4 to 6.6, even more preferably 2.6 to 6, even more preferably 2.8 to 5.6, even more preferably 2.8 to 5.2, and even more preferably 2.8 to 4.8.

[0072] The ratio of the content of the conductive polymer compound in the resin layer A to the content of the binder resin in the resin layer A (content of the conductive polymer compound / content of the binder resin) is preferably 0.01 to 0.5, more preferably 0.01 to 0.4, and even more preferably 0.01 to 0.3.

[0073] It is preferable that the resin layer A, i.e., the resin composition A, does not contain a crosslinking agent. By not containing a crosslinking agent, the dispersibility of the conductive compound becomes good, and it becomes easier to ensure the desired dielectric properties and antistatic performance. The crosslinking agent is a component that crosslinks the binder resin and is a component other than the binder resin described above. The absence of a crosslinking agent means that the resin composition A does not contain a crosslinking agent, and the resin layer A is a resin layer that is not crosslinked by a crosslinking agent. Examples of the crosslinking agent include melamine compounds, epoxy compounds, oxazoline compounds, isocyanate compounds, carbodiimide compounds, silane coupling compounds, hydrazide compounds, and aziridine compounds. In addition, instead of using a crosslinking agent, the durability of the resin layer A can be improved by making the binder resin act like a crosslinking agent.

[0074] Furthermore, the resin layer A, i.e., the resin composition A, may contain additives other than those described above, such as a surfactant. The use of a surfactant in the resin layer A can improve the dispersibility of each component. Examples of surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. The content of the surfactant in the resin layer A is preferably in the range of 0.5 to 15% by mass, more preferably 1 to 10% by mass, and even more preferably 2 to 8% by mass. Furthermore, the resin layer A, i.e., the resin composition A, may contain additives other than the surfactant, and examples of such additives include antifoaming agents, coatability improvers, thickeners, organic lubricants, ultraviolet absorbers, antioxidants, foaming agents, dyes, pigments, etc. The contents of the various components in the resin layer A described above can also be considered as the proportions of all non-volatile components in the resin composition A that forms the resin layer A. The contents of the various components in the resin layer B described below can also be considered as the proportions of all non-volatile components in the resin composition B that forms the resin layer B.

[0075] (Resin layer B) The laminate film of the present invention preferably has a resin layer B on the opposite side of the base film (i.e., the side opposite to the side on which resin layer A is provided). That is, the laminate film of the present invention preferably has resin layers on both sides of the base film. Resin layer B may be formed directly on the base film such as a polyester film, or another layer may be provided between the base film such as a polyester film and resin layer B. By including resin layer B in addition to resin layer A, the laminate film can more easily achieve the desired low dielectric constant characteristics. Therefore, it is possible to improve antistatic performance while more easily prevent malfunctions in integrated image display devices and the like.

[0076] Resin layer B is a resin layer formed from resin composition B. Resin layer B, i.e., resin composition B, may contain a binder resin, preferably contains a binder resin and a conductive polymer compound, and more preferably contains a binder resin, a conductive polymer compound, and a polyglycerin-based compound. The details of the binder resin, the conductive polymer compound, and the polyglycerin-based compound, as well as the details of their contents, are as described above for resin layer A. Although the contents have been described above as the contents in resin layer A, they may be interpreted as the contents in resin layer B.

[0077] Furthermore, it is preferable that resin layer B, i.e., resin composition B, does not contain a crosslinking agent, similar to resin layer A. Therefore, it is preferable that no crosslinking agent is blended into resin composition B, and resin layer B is a resin layer that is not crosslinked by a crosslinking agent. Furthermore, resin layer B, i.e., resin composition B, may contain a surfactant and other additives, the details of which are as described above for resin layer A.

[0078] The composition of resin layer B may be the same as or different from the composition of resin layer A. By making the compositions of resin layer A and resin layer B different, the surface resistivity of one of resin layers A and B can be made lower than the surface resistivity of the other, thereby adjusting the dielectric constant. For example, from the viewpoint of adjusting the dielectric constant and antistatic properties, the content (mass %) of the conductive polymer compound in one of the resin layers A and B may be higher than the content (mass %) of the conductive polymer compound in the other resin layer. The type of conductive polymer compound in one resin layer may be different from the type of conductive polymer compound in the other resin layer. In this case, the content (mass %) of the conductive polymer compound may be appropriately adjusted from the viewpoints of adjusting the dielectric constant and antistatic properties. Specifically, one resin layer may contain a thiophene-based compound, for example, in a preferred content of the conductive polymer compound described above (i.e., 1 to 20 mass %, more preferably 1 to 18 mass %, even more preferably 1 to 16 mass %, and even more preferably 4 to 16 mass %), while the other resin layer may contain a thiophene-based compound and a polyaniline compound, for example, in a content suitable for use in combination as described above. Furthermore, from the viewpoint of adjusting the dielectric constant and antistatic properties, one resin layer may contain a polyglycerin-based compound, while the other resin layer may not contain a polyglycerin-based compound, or if it does contain a polyglycerin-based compound, the content (mass %) of the polyglycerin-based compound may be less than that of the other resin layer. In addition, from the viewpoint of appropriately adjusting the dielectric constant, it is also preferable to use a thiophene-based compound and a polyaniline compound in at least one of the resin layer A and the resin layer B in combination.

[0079] The various components in the resin layer can be analyzed by, for example, TOF-SIMS, ESCA, fluorescent X-ray analysis, or the like.

[0080] <Thickness of resin layer> The thickness of the resin layer A is preferably 0.002 μm to 1 μm, more preferably 0.005 μm to 0.5 μm, even more preferably 0.01 μm to 0.25 μm, still more preferably 0.02 μm to 0.15 μm, and even more preferably 0.03 μm to 0.1 μm. If the thickness of the resin layer A is within the above range, transparency, coating appearance, low dielectric constant characteristics, coating cost, etc. tend to be good. The thickness of the resin layer B is also the same as that of the resin layer A, and a detailed description thereof will be omitted.

[0081] <Method for forming resin layer> Next, a method for forming the resin layers (that is, resin layers A and B) provided on a base film such as a polyester film will be described. The resin layer is formed from resin composition A or resin composition B, and specifically, can be formed by applying resin composition A or resin composition B to a substrate film, and drying and curing the applied resin as necessary. The method for applying the resin composition is not particularly limited, and any conventionally known coating method can be used, such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, curtain coating, and the like. The resin layer can be formed by in-line coating or off-line coating. The drying and curing conditions are not particularly limited. For example, when forming the resin layer by off-line coating, the heat treatment is typically carried out at 80 to 200°C for 3 to 40 seconds, preferably at 100 to 180°C for 3 to 40 seconds. On the other hand, when forming the resin layer by in-line coating, the heat treatment is typically carried out at 70 to 280°C for 3 to 200 seconds.

[0082] In the present invention, the resin layer is preferably formed by in-line coating, which treats the surface of a substrate film such as a polyester film during the film-forming process. Inline coating is a method of coating within the manufacturing process of a substrate film such as a polyester film. Specifically, it is a method of coating at any stage between melt extrusion of a resin such as polyester, stretching, heat setting, and winding up. Typically, coating is performed on an unstretched sheet obtained by melting and quenching, a stretched uniaxially stretched film, a biaxially stretched film before heat setting, or a film after heat setting and before winding up. While not limited to the following, for example, in sequential biaxial stretching, a method in which a uniaxially stretched film stretched in the longitudinal direction (machine direction) is coated and then stretched in the transverse direction is particularly advantageous. This method offers advantages in terms of production cost, since the formation of the substrate film and the formation of the resin layer can be performed simultaneously. Furthermore, since stretching is performed after coating, the thickness of the resin layer can be changed by adjusting the stretch ratio, making thin-film coating easier than offline coating. Furthermore, by providing a resin layer on the substrate film before stretching, the resin layer can be stretched together with the substrate film, thereby firmly adhering the resin layer to the substrate film. Furthermore, for example, in the production of a biaxially stretched polyester film, the film can be stretched while being held at its edges with clips or the like, thereby restraining the film in both the longitudinal and transverse directions, and in the heat setting step, high temperatures can be applied while maintaining flatness and without wrinkles, etc. Therefore, the heat treatment performed after coating can be performed at a high temperature that cannot be achieved by other methods, improving the film-forming properties of the resin layer and enabling stronger adhesion between the resin layer and the substrate film, and further enabling a stronger resin layer to be formed, thereby improving performance such as adhesion to various functional layers (e.g., pressure-sensitive adhesive layer and release layer) formed on the resin layer, and moist heat resistance.

[0083] When forming a resin layer by inline coating, it is preferable to coat the resin composition onto a substrate film in the form of an aqueous solution or aqueous dispersion, with the resin composition adjusted to a solids concentration (total non-volatile components) of approximately 0.1 to 50 mass %.

[0084] In addition, regardless of whether off-line coating or in-line coating is used, heat treatment and irradiation with active energy rays such as ultraviolet radiation may be used in combination as needed. The substrate film constituting the laminated film of the present invention may be previously subjected to a surface treatment such as a corona treatment or a plasma treatment.

[0085] <<Adhesive layer>> In one embodiment of the present invention (hereinafter also referred to as "first embodiment"), a pressure-sensitive adhesive layer is provided on the opposite surface of the base film (i.e., the surface opposite to the surface on which resin layer A is provided). When resin layer B is provided on the opposite surface, the pressure-sensitive adhesive layer is preferably formed on resin layer B.

[0086] 1, the laminate film 10 in the first embodiment includes a base film 11, a resin layer A provided on one surface of the base film 11, a resin layer B provided on the opposite surface of the base film 11, and a pressure-sensitive adhesive layer 12 provided on resin layer B of the base film 11. The laminate film 10 having the above configuration can be suitably used, for example, as a protective film. However, the laminate film 10 according to this embodiment may have layers other than these, and for example, a primer layer that improves the adhesion between the resin layer B and the base film 11 may be provided between the resin layer A and the base film 11, or between the resin layer B and the base film 11. Furthermore, the resin layer B may be omitted, in which case the pressure-sensitive adhesive layer 12 may be directly laminated on the opposite surface of the base film 10.

[0087] The adhesive layer in this embodiment is not particularly limited, but from the viewpoint of PFAS regulations, it is preferable that the adhesive layer be formed from a weakly adhesive adhesive that does not contain a fluorine component and can be peeled off after being attached to an adherend. The adhesive layer is preferably formed from an adhesive, and examples of the adhesive that can be used include acrylic adhesives, urethane adhesives, and silicone adhesives. A general-purpose adhesive may be used as the adhesive, and it is preferable that the adhesive does not contain an antistatic agent and does not have antistatic properties. Examples of the antistatic agent include the conductive polymer compounds described above and known antistatic agents other than conductive polymer compounds. Even if the adhesive layer of the laminated film of the present invention is formed using an adhesive that does not have antistatic properties, the film can have antistatic properties by having resin layer A, or resin layer A and resin layer B. The thickness of the adhesive layer is not particularly limited, but is preferably in the range of 5 to 500 μm, more preferably 10 to 300 μm, and particularly preferably 20 to 200 μm, in order to exert adhesive strength to the adherend.

[0088] (acrylic adhesive) The acrylic pressure-sensitive adhesive can be formed from a conventionally known acrylic pressure-sensitive adhesive composition, and can be formed from a pressure-sensitive adhesive composition containing a (meth)acrylic acid ester (co)polymer and, if necessary, further containing a photopolymerization initiator, a crosslinking agent, a silane coupling agent, and other materials. For example, the pressure-sensitive adhesive composition described in JP 2019-210446 A can be used.

[0089] (urethane adhesive) The urethane-based adhesive can be formed from a urethane-based adhesive composition containing a reaction product of a polyol as a urethane-based base polymer and a polyisocyanate compound. Examples of the polyol component include polymer-type polyols such as polyester polyols, polyether polyols, polycarbonate polyols, caprolactone polyols, etc. These polyol components may be used alone or in combination of two or more. Examples of polyisocyanate compounds include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates. These polyisocyanate compounds may be used alone or in combination of two or more.

[0090] (Silicone adhesive) The silicone-based pressure-sensitive adhesive can be formed from a silicone-based pressure-sensitive adhesive composition containing a silicone resin as a main component resin. The term "main component resin" refers to the resin that has the largest content (by mass) among the resins that make up the adhesive. Examples of adhesive compositions that contain a silicone resin as the main component resin include addition reaction, peroxide curing, and condensation reaction silicone adhesives. Among these, addition reaction silicone adhesives are preferably used because they can be cured at low temperatures in a short time. These addition reaction silicone adhesives form an adhesive layer on the support by curing. When an addition reaction silicone adhesive is used as the silicone adhesive, the silicone adhesive may contain a catalyst such as a platinum catalyst.

[0091] For example, an addition reaction type silicone pressure-sensitive adhesive can be prepared by, if necessary, adding a catalyst such as a platinum catalyst to a silicone resin solution diluted with a solvent such as toluene, stirring the mixture until uniform, applying the mixture to a support, and then heating the mixture for 1 to 5 minutes at 100 to 130° C. If necessary, a crosslinking agent or an additive for controlling adhesive strength may be added to the addition reaction type silicone pressure-sensitive adhesive, or the substrate film may be treated with a primer before the pressure-sensitive adhesive layer is formed.

[0092] Commercially available silicone resins used in addition reaction type silicone pressure sensitive adhesives include, for example, SD4580PSA, SD4584PSA, SD4585PSA, SD4587LPSA, SD4560PSA, SD4570PSA, SD4600FCPSA, SD4593PSA, DC7651ADHESIVE, DC7652ADHESIVE, LTC-755, LTC-310 (all manufactured by Dow Corning Toray Co., Ltd.), KR-3700, KR-3701, KR-3704, X-40-3237-1, X-40-3240, Examples of suitable anti-inflammatory agents include X-40-3291-1, X-40-3229, X-40-3323, X-40-3306, and X-40-3270-1 (all manufactured by Shin-Etsu Chemical Co., Ltd.), AS-PSA001, AS-PSA002, AS-PSA003, AS-PSA004, AS-PSA005, AS-PSA012, AS-PSA014, and PSA-7465 (all manufactured by Arakawa Chemical Industries, Ltd.), and TSR1512, TSR1516, and TSR1521 (all manufactured by Momentive Performance Materials, Inc.).

[0093] <<Release layer>> In another embodiment of the present invention (hereinafter also referred to as "second embodiment"), a release layer is provided on the opposite surface of the substrate film (i.e., the surface opposite to the surface on which resin layer A is provided). When resin layer B is provided on the opposite surface, the release layer is preferably formed on resin layer B. Furthermore, a pressure-sensitive adhesive layer is preferably further provided on the release layer. 2, the laminated film 10A according to the second embodiment comprises, in this order, a base film 11, a resin layer A provided on one surface of the base film 11, a resin layer B provided on the opposite surface of the base film 11, and a release layer 13 and a pressure-sensitive adhesive layer 12A provided on resin layer B of the base film 11. The laminated film 10 having the above configuration can be used as a release film with a pressure-sensitive adhesive layer. That is, for example, a laminate consisting of layers from resin layer A to release layer 13 serves as a release film (hereinafter, for convenience, may be referred to as "first release film") 15 that can be peeled from the adhesive layer. The release film with the adhesive layer is preferably peeled from the adhesive layer 12A after the surface of the adhesive layer 12A is bonded to an adherend. The first release film 15 is used to protect the adhesive layer before being peeled from the adhesive layer 12A. The first release film 15 can also be used to protect the adherend after the surface of the adhesive layer 12A is bonded to the adherend and before being peeled from the adhesive layer 12A. On the other hand, the adhesive layer remaining on the adherend after the first release film 15 is peeled off is preferably used as an adhesive layer that bonds adherends together. However, the laminate film 10A according to this embodiment may have layers other than these, and for example, a primer layer that improves the adhesion between the resin layer B and the base film 11 may be provided between the resin layer A and the base film 11 or between the resin layer B and the base film 11. Furthermore, the resin layer B may be omitted, in which case the release layer 13 may be directly laminated on the opposite surface of the base film 11. Furthermore, in the second embodiment in which the laminated film has a release layer, the adhesive layer 12A may be omitted, that is, the laminated film may be the release film 15.

[0094] The pressure-sensitive adhesive layer 12A used in the second embodiment is as described above, but the pressure-sensitive adhesive layer 12A serves as a layer for bonding adherends, such as optical components such as OCA. Therefore, the pressure-sensitive adhesive layer 12A in the second embodiment is preferably formed from a pressure-sensitive adhesive having high adhesive strength to the adherend. The adhesive strength can be adjusted by a conventionally known method.

[0095] The release layer may be, for example, a silicone-based release layer containing a silicone resin-based release agent. Examples of silicone resin-based release agents include curable silicone resins, and the release layer is a layer formed by curing a release layer composition containing a curable silicone resin as a main component resin, and is disposed on the opposite side of the above-mentioned substrate film. The release layer can also be said to be a release layer containing a cured product formed by curing the release layer composition.

[0096] In addition, the "main component resin" in the release layer means the resin with the largest mass proportion among the resins constituting the release layer composition, and is expected to account for 50 mass% or more, 75 mass% or more, 90 mass% or more, or 100 mass% of the resins constituting this release layer composition.

[0097] The curable silicone resin may be a resin containing a curable silicone resin as a main component, or a modified silicone obtained by graft polymerization with an organic resin such as an acrylic resin, a urethane resin, an epoxy resin, an alkyd resin, etc. In addition, when the pressure-sensitive adhesive layer used in combination is a silicone pressure-sensitive adhesive, it is preferable that the resin contains a fluorosilicone resin, etc.

[0098] The type of curable silicone resin may be any of the existing curing reaction types, such as heat-curable types such as addition types or condensation types, or electron beam-curable types such as ultraviolet curable types, or a combination of multiple types of curable silicone resins. Furthermore, there are no particular limitations on the form of application of the curable silicone resin when forming the release layer, and it may be in the form of a solution in an organic solvent, a solvent-free form, or an aqueous emulsion.

[0099] The solventless curable silicone resin is a silicone resin with a viscosity that allows it to be applied without diluting it with a solvent, and is a silicone resin that is made up of short polysiloxane chains and has a relatively low molecular weight. On the other hand, solvent-based curable silicone resins are silicone resins that have such a high viscosity that they cannot be applied unless diluted with a solvent, and have a relatively high molecular weight compared to solventless curable silicone resins. A solvent-curable silicone resin is preferred from the viewpoints of providing good adhesion to the base film or resin layer B, providing a uniform coat appearance without coating unevenness, and making it easy to adjust the thickness of the release layer.

[0100] The curable silicone resin used in the present invention is preferably composed of a base compound and a silicone crosslinking agent for crosslinking the base compound. There are no limitations on the type of curable silicone resin, but from the viewpoint of excellent release properties such as easy peelability, it is preferable to use a curable silicone resin containing an alkenyl group as the base compound. Examples of the curable silicone resin containing an alkenyl group include diorganopolysiloxanes represented by the following general formula (4): R (3-a) X a SiO-(RXSiO) m -(R2SiO) n -SiX a R (3-a) ···(4)

[0101] In general formula (4), R is a monovalent hydrocarbon group having 1 to 10 carbon atoms, and X is an organic group containing an alkenyl group. a is an integer of 0 to 3, preferably 1, and m is 0 or greater; however, when a = 0, m is 2 or greater, and m and n are numbers that satisfy 100 ≦ m + n ≦ 20,000. Furthermore, the above formula does not represent a block copolymer; the structural unit in parentheses of m and the structural unit in parentheses of n may be bonded randomly. The same applies to formula (5) described below. Specific examples of R include alkyl groups such as methyl, ethyl, propyl, and butyl, cycloalkyl groups such as cyclohexyl, and aryl groups such as phenyl and tolyl, with methyl and phenyl being particularly preferred. X is preferably an alkenyl-containing organic group having 2 to 10 carbon atoms, with specific examples including vinyl, allyl, hexenyl, octenyl, acryloylpropyl, acryloylmethyl, methacryloylpropyl, cyclohexenylethyl, and vinyloxypropyl, with vinyl and hexenyl being particularly preferred. Specific examples of curable silicone resins include dimethylsiloxane-methylhexenylsiloxane copolymers capped at both molecular chain terminals with trimethylsiloxy groups (e.g., 96 mol% dimethylsiloxane units, 4 mol% methylhexenylsiloxane units), dimethylsiloxane-methylhexenylsiloxane copolymers capped at both molecular chain terminals with dimethylvinylsiloxy groups (e.g., 97 mol% dimethylsiloxane units, 3 mol% methylhexenylsiloxane units), and dimethylsiloxane-methylhexenylsiloxane copolymers capped at both molecular chain terminals with dimethylhexenylsiloxy groups (e.g., 95 mol% dimethylsiloxane units, 5 mol% methylhexenylsiloxane units).

[0102] When a curable silicone resin containing alkenyl groups is used as the curable silicone resin, it is preferable that the curable silicone resin further contains a polyorganosiloxane containing SiH groups. The polyorganosiloxane containing SiH groups can serve as a silicone crosslinking agent that crosslinks the curable silicone resin containing alkenyl groups. The polyorganosiloxane containing SiH groups reacts with the curable silicone resin containing alkenyl groups to form a stronger silicone release layer. The polyorganosiloxane containing SiH groups is an organohydrogenpolysiloxane having at least two, preferably three or more, hydrogen atoms bonded to silicon atoms per molecule, and can be linear, branched, or cyclic. Examples of suitable polyorganosiloxanes include compounds represented by the following general formula (5), but are not limited to these. H b R 1 (3-b) SiO-(HR 1 SiO) x -(R 1 2SiO) y -SiR 1 (3-b) H b ···(5)

[0103] In general formula (5), R 1is a monovalent hydrocarbon group having 1 to 6 carbon atoms and containing no aliphatic unsaturated bonds. b is an integer from 0 to 3, and x and y are each an integer. Specific examples include methylhydrogenpolysiloxane capped at both molecular chain terminals with trimethylsiloxy groups, dimethylsiloxane-methylhydrogensiloxane copolymer capped at both molecular chain terminals with trimethylsiloxy groups, methylhydrogenpolysiloxane capped at both molecular chain terminals with dimethylhydrogensiloxy groups, and dimethylsiloxane-methylhydrogensiloxane copolymer capped at both molecular chain terminals with dimethylhydrogensiloxy groups.

[0104] Specific examples of commercially available silicone resins that can be used in the present invention include KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-856, X-62-2422, X-62-2461, X-62-1387, X-62-2888L, X-62-5039, X-62-5040, KNS-3051, X-62-1496, KNS320A, KNS316, X-62-1574A / B, X-62-7052, X-62-7028A / B, X-62-7619, X-62-7213, and X-41-3035 manufactured by Shin-Etsu Chemical Co., Ltd.; and YSR-3022 manufactured by Momentive Performance Materials. TPR-6700, TPR-6720, TPR-6721, TPR6500, TPR6501, UV9300, UV9425, XS56-A2775, XS56-A2982, UV9430, TPR6600, TPR6604, TPR6605, Dow Corning Toray Co., Ltd. products include SRX357, SRX211, SD7220, S Examples include, but are not limited to, D7292, LTC750A, LTC760A, LTC303E, SP7259, BY24-468C, SP7248S, BY24-452, DKQ3-202, DKQ3-203, DKQ3-204, DKQ3-205, DKQ3-210, and DEHESIVE 636, 919, 920, 921, 924, 929, and the like from the DEHESIVE series manufactured by Wacker Asahi Kasei Silicones Co., Ltd.

[0105] The release layer preferably uses a platinum-based catalyst as a curing catalyst for promoting the addition reaction, and examples of this component include platinum-based compounds such as chloroplatinic acid, an alcohol solution of chloroplatinic acid, a complex of chloroplatinic acid with an olefin, and a complex of chloroplatinic acid with an alkenylsiloxane, as well as platinum black, platinum supported on silica, and platinum supported on activated carbon.

[0106] The content of the curing catalyst in the release layer is preferably 0.5 to 500 ppm by mass, more preferably 5 ppm by mass or more, even more preferably 10 ppm by mass or more, and more preferably 300 ppm by mass or less, and even more preferably 200 ppm by mass or less, based on the curable silicone resin. When the content of the platinum-based catalyst in the release layer is equal to or greater than the lower limit, sufficient release force is obtained, the curing reaction proceeds sufficiently, and problems such as deterioration of the coated surface condition do not occur. On the other hand, when the content of the platinum-based catalyst in the release layer is equal to or less than the upper limit, in addition to being advantageous in terms of cost, reactivity is increased, and problems such as the generation of gel foreign matter do not occur.

[0107] In addition, because addition reactions are very reactive, acetylene alcohol may be added as a reaction inhibitor in some cases. The component is an organic compound having a carbon-carbon triple bond and a hydroxyl group, preferably a compound selected from the group consisting of 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and phenylbutynol.

[0108] The content of the reaction inhibitor is preferably 0.001 to 5.0 parts by mass, more preferably 0.01 to 2.0 parts by mass, even more preferably 0.05 to 1.5 parts by mass, and most preferably 0.1 to 0.5 parts by mass per 100 parts by mass of the total amount of the release layer composition (based on non-volatile components). By keeping the content within the above range, the curing of the curable silicone resin is not inhibited without reducing the reaction activity, and the easy releasability of the first release film can be ensured.

[0109] The release layer constituting the first release film can be used in combination with a catalyst for the purpose of accelerating hydrolysis and condensation reactions. Specific examples of such catalysts include organic acids such as acetic acid, butyric acid, maleic acid, and citric acid; inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, and sulfuric acid; basic compounds such as triethylamine; organometallic salts such as tetrabutyl titanate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctate, dibutyltin diolate, diphenyltin diacetate, dibutyltin oxide, dibutyltin dimethoxide, dibutylbis(triethoxysiloxy)tin, and dibutyltin benzyl maleate; and fluorine-containing compounds such as KF and NHF. The above catalysts may be used alone or in combination of two or more. Among these, organometallic salts are preferred because they provide particularly good coating durability.

[0110] In order to adjust the releasability of the release layer, various release control agents may be used in combination. When increasing the release strength, organopolysiloxane resins, silica particles, silicones with high release strength, etc. may generally be contained in the release layer in an appropriate amount as heavy release agents to obtain the desired release strength. Among these, organopolysiloxane resins and silicone resins such as silicone are preferred.

[0111] Specific examples of commercially available heavy release agents include X-92-183 and KS-3800 manufactured by Shin-Etsu Chemical Co., Ltd., and SD7292, BY24-843, and BY24-4980 manufactured by Dow Corning Toray Co., Ltd.

[0112] The content of the silicone resin as a heavy release agent in the silicone resin is usually 1 to 20% by mass, preferably 5 to 30% by mass, and more preferably 10 to 25% by mass. By setting the content of the heavy release agent within the above range, it becomes easier to achieve the desired release properties.

[0113] To lighten the release force, a low molecular weight siloxane compound or the like can be appropriately selected as a light release agent and incorporated into the release layer at an appropriate content so that the siloxane migrating component can exhibit release performance. Examples of low molecular weight siloxane compounds include low molecular weight cyclic siloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane. In addition to these low molecular weight cyclic siloxanes, other compounds include dimethylsiloxane oligomers with trimethylsiloxy groups blocked at both molecular chain ends; dimethylsiloxane oligomers with dimethylhydroxysiloxy groups blocked at both molecular chain ends; and the like. These compounds may be used in combination as needed.

[0114] The release layer composition may optionally use a silicone oil having a dimethylsiloxane skeleton (DM) represented by the following formula (6) and a methylphenylsiloxane skeleton (MP) represented by the following formula (7) as a light release agent. By having the dimethylsiloxane skeleton (DM) and the methylphenylsiloxane skeleton (MP), even if the light release agent migrates to the pressure-sensitive adhesive layer to be bonded, it is able to penetrate into the pressure-sensitive adhesive layer, thereby reducing a decrease in adhesive strength. The molar ratio of the dimethylsiloxane skeleton (DM) represented by the following formula (6) to the methylphenylsiloxane skeleton (MP) represented by the following formula (7) (DM:MP) is preferably in the range of 98:2 to 70:30, more preferably 95:5 to 80:20, and particularly preferably 92:8 to 85:15. By keeping the DM:PM ratio within the above range, the releasability of the first release film can be ensured. The light release agent preferably has a weight average molecular weight of less than 10,000. When the weight average molecular weight of the light release agent is less than 10,000, it is advantageous in terms of migration and light release properties.

[0115] [ka]

[0116] [ka]

[0117] The content of the light release agent, such as a low-molecular-weight siloxane compound, is typically 0.1 to 15.0% by mass, preferably 0.5 to 10.0% by mass, and more preferably 0.5 to 5.0% by mass, relative to 100% by mass of the silicone resin in the release layer. When the content is 0.1% by mass or more, the migratory component is sufficient, resulting in sufficient release properties and achieving the desired light release properties. Furthermore, when the content is 15.0% by mass or less, the migratory component does not precipitate excessively, eliminating concerns about process contamination.

[0118] The release layer composition may contain a dilution solvent, if necessary. Examples of dilution solvents include aromatic hydrocarbons such as toluene, aliphatic hydrocarbons such as hexane, heptane, and isooctane, esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone (MEK) and isobutyl methyl ketone, alcohols such as ethanol and 2-propanol, and ethers such as diisopropyl ether and dibutyl ether. These are preferably used alone or in combination, taking into consideration solubility, coatability, boiling point, and the like.

[0119] In addition, it is preferable to use an organosilicon compound represented by the following general formula (8) in the release layer in order to improve the coating adhesion to the film. Si(X) d (Y) e (R 1 ) f ···(8) [In the above formula, X represents an organic group having at least one selected from an epoxy group, a mercapto group, a (meth)acryloyl group, an alkenyl group, a haloalkyl group, and an amino group; R 1 is a monovalent hydrocarbon group having 1 to 10 carbon atoms, Y is a hydrolyzable group, d is an integer of 1 or 2, e is an integer of 2 or 3, f is an integer of 0 or 1, and d+e+f=4.

[0120] The organosilicon compound represented by the general formula (8) can be one having two hydrolyzable groups Y (D unit source) or three hydrolyzable groups Y (T unit source) that can form a siloxane bond by hydrolysis and condensation reaction.

[0121] In the general formula (8), the monovalent hydrocarbon group R 1 The alkyl group may have 1 to 10 carbon atoms, and is preferably an alkyl group, particularly a methyl group, an ethyl group, or a propyl group.

[0122] In general formula (8), examples of the hydrolyzable group Y include methoxy, ethoxy, butoxy, isopropenoxy, acetoxy, butanoxime, and amino groups. These hydrolyzable groups may be used alone or in combination. Among these, methoxy and ethoxy groups are particularly preferred because they can impart good storage stability to the release layer composition as a coating agent and have appropriate hydrolysis properties.

[0123] Specific examples of organosilicon compounds contained in the release layer include vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 5-hexenyltrimethoxysilane, p-styryltrimethoxysilane, trifluoropropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and γ-glycidoxypropylmethyldiisopropenoxysilane.

[0124] It is preferable that the release layer does not substantially contain particles. By substantially not containing particles in the release layer, it is possible to stabilize the release properties while reducing migration. Note that "substantially not containing" means that the release layer may contain particles in a small amount so as not to impair the effects of the present invention, and for example, it may contain particles that are inevitably mixed in. The specific particle content in this release layer is, for example, less than 0.05% by mass, preferably less than 0.01% by mass, and more preferably less than 0.0001% by mass. Note that the range of the particle content in the release layer composition based on non-volatile components is also the same as the above-mentioned particle content.

[0125] Furthermore, within the scope of the present invention, the release layer, i.e., the release layer composition, may contain, as necessary, an antifoaming agent, a coating property improver, a thickener, an organic lubricant, an antistatic agent, a conductive agent, an ultraviolet absorber, an antioxidant, a foaming agent, a dye, a pigment, etc. However, it is preferable that the release layer does not contain an antistatic agent and does not have antistatic properties. Even if the release layer does not have antistatic properties, the laminate film can have the desired antistatic properties by providing resin layer A, or resin layer A and resin layer B.

[0126] The number-average molecular weight (Mn) of the curable silicone resin is preferably 1,000 or more and 1,000,000 or less. When the number-average molecular weight (Mn) of the curable silicone resin is equal to or greater than the lower limit, the amount of low-molecular-weight silicone resin eluted or transferred to the adhesive layer can be reduced when the adhesive layer is laminated on the release layer, and the thick coating of the release layer can facilitate easy release. On the other hand, when the number-average molecular weight (Mn) of the curable silicone resin is equal to or less than the upper limit, the viscosity increases, preventing a decrease in the fluidity of the release layer composition. Therefore, when the release layer composition is applied, streaky coating unevenness can be prevented, and the release layer surface can be easily smoothed. From this viewpoint, the number average molecular weight (Mn) of the curable silicone resin is preferably 1000 or more, more preferably 3000 or more, even more preferably 5000 or more, and particularly preferably 10000 or more. On the other hand, it is preferably 1000000 or less, more preferably 200000 or less, and even more preferably 100000 or less.

[0127] From the same viewpoint as the number average molecular weight, the mass average molecular weight (Mw) of the curable silicone resin is preferably 2,000 to 2,000,000, more preferably 5,000 or more, even more preferably 10,000 or more, and especially preferably 15,000 or more, and more preferably 250,000 or less, even more preferably 100,000 or less.

[0128] The ratio (Mw / Mn) of the mass average molecular weight (Mw) to the number average molecular weight (Mn) of the curable silicone resin is preferably 1.0 to 5.0, more preferably 1.5 to 3.5, and even more preferably 2.0 to 3.0. By satisfying this range, it is expected that the crosslinking reaction will proceed efficiently.

[0129] The curable silicone resin may be a combination of two or more curable silicone resins. In this case, the average number-average molecular weight (Mn) and mass-average molecular weight (Mw) of the two or more curable silicone resins preferably fall within the above-mentioned ranges. The term "average" here refers to a weighted average weighted by the mass of each resin. When a base resin and a silicone crosslinker are used as the curable silicone resin, the number-average molecular weight (Mn), mass-average molecular weight (Mw), and Mw / Mn of the base resin should preferably fall within the above-mentioned ranges. The number-average molecular weights and mass-average molecular weights of the silicone resin, light release agent, and heavy release agent should preferably be measured by gel permeation chromatography (GPC).

[0130] The viscosity of the curable silicone resin at 25° C. when adjusted to 15% by mass by dilution with n-heptane solvent is preferably 1 to 400 mcps, more preferably 5 to 300 mcps, and even more preferably 10 to 200 mcps. If the viscosity of the curable silicone resin is 1 mcps or more, the appropriate viscosity of the coating liquid suppresses repelling and results in a uniform coating appearance with high visibility, which is preferable. If the viscosity is 400 mcps or less, the fluidity of the release layer composition can be maintained, the occurrence of streaky coating unevenness when the release layer composition is applied can be suppressed, and the release layer surface can be made smooth. When a base resin and a silicone crosslinking agent are used as the curable silicone resin, it is preferable that the viscosity of the base resin is within the above range.

[0131] When the curable silicone resin has alkenyl groups in the silicone resin, the content of the alkenyl groups is preferably 0.4 to 2.5 mol%, more preferably 0.5 to 2.0 mol%, and even more preferably 0.5 to 1.5 mol% relative to the total amount of siloxane components. By satisfying this range, a certain amount or more of alkenyl groups is contained, so that the release layer is sufficiently cured, and on the other hand, the amount of alkenyl groups is not excessive, so that the peel force after exposure to air can be prevented from increasing.

[0132] When the curable silicone resin has Si-H groups in the silicone resin, the content of the Si-H groups is preferably 0.8 to 2.5 mol%, more preferably 0.8 to 2.0 mol%, and even more preferably 1.0 to 2.0 mol% relative to the total amount of siloxane components. By satisfying this range, a certain amount or more of Si-H groups is contained, so that the release layer is sufficiently cured, and on the other hand, since the amount of Si-H groups is not excessive, reaction with the adhesive layer is prevented, and the release layer can be suppressed from becoming difficult to release.

[0133] The curable silicone resin may contain alkenyl groups and Si-H groups (also simply referred to as "H groups") in the side chains and / or terminals of the main chain consisting of siloxane bonds within the same structure. In this case, it is also preferable that the content of alkenyl groups and Si-H groups in the curable silicone resin be within the above-mentioned ranges.

[0134] The thickness of the release layer is preferably 0.1 to 2.0 g / m when expressed in terms of mass per unit area. 2 The thickness of the release layer is 0.1 g / m 2 By setting the thickness to 2.0 g / m or more, it becomes easier to make the release layer lightly peelable. 2 By setting the thickness to the range below 0.1 to 1.5 g / m, it is possible to prevent the components of the release layer from migrating to the pressure-sensitive adhesive layer and the like, and it is also possible to appropriately prevent blocking. 2 , and more preferably 0.1 to 1.0 g / m 2 The range is. As will be described later, the release layer may be formed by applying a release layer composition and drying it, and the thickness of the release layer is the thickness after drying.

[0135] The release layer may be formed by in-line coating, which treats the film surface during the film-forming process of the substrate film, or by offline coating, which applies the release layer to a substrate film that has already been produced outside the system. Offline coating is more preferred. The release layer may be formed by applying a release layer composition to the surface of the substrate film and, if necessary, curing and drying the composition. The release layer may be formed on a substrate film on which resin layer A or resin layer A and resin layer B have been formed.

[0136] The release layer composition can be applied to the substrate film by any conventional coating method such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, or curtain coating.

[0137] The curing conditions for forming the release layer are not particularly limited. When forming the release layer by offline coating, the heat treatment is usually carried out at 80°C or higher for 10 seconds or more, preferably at 100 to 200°C for 3 to 40 seconds, more preferably at 120 to 190°C for 3 to 40 seconds, and even more preferably at 150 to 180°C for 3 to 40 seconds. When the release layer composition applied to the substrate film is diluted with a solvent, the solvent may be evaporated by drying. Drying may be performed, for example, by heating during curing of the release layer.

[0138] If necessary, heat treatment may be combined with irradiation of active energy rays such as ultraviolet rays. Known devices and energy sources can be used as the energy source for curing by irradiation of active energy rays. Examples of light sources include fusion (H) lamps, metal halide lamps, high-pressure mercury lamps (ozone-generating types and ozone-less types), and UV-LEDs.

[0139] The active energy ray irradiation is not particularly limited, but in the case of ultraviolet irradiation, the cumulative light dose is 10 to 3000 mJ / cm. 2 , preferably 50 to 2000 mJ / cm 2 , and more preferably 100 to 1000 mJ / cm 2 By setting the integrated light amount of ultraviolet irradiation within the above range, the curing of the release layer is promoted, and on the other hand, by not irradiating it excessively, the release layer is not destroyed and the peeling force after irradiation can be prevented from becoming heavy.

[0140] (Dielectric constant of resin layer A surface) In the laminate film of the present invention, the dielectric constant of the surface of the resin layer A is 5.5 or less. If the dielectric constant of the surface of the resin layer A is greater than 5.5, the low dielectric constant characteristics become insufficient. As a result, appropriate conductive characteristics cannot be ensured, and when the laminate film is used, for example, to protect an image display device (e.g., a smartphone) that integrates an OLED and a touch sensor, or to protect an adhesive layer that bonds components mounted on such an image display device, the touch panel may malfunction. The laminate film of the present invention may be used, for example, as a process film during the manufacture of an integrated image display device. In such cases, an operation check test may be performed while the laminate film of the present invention is attached to an adherend. However, if the dielectric constant is greater than 5.5, problems such as malfunctions preventing the operation check test from being performed properly may occur. The dielectric constant of the surface of the resin layer A in the laminate film is preferably 5.0 or less, more preferably 4.5 or less, and even more preferably 3.8 or less. Meanwhile, the lower limit of the dielectric constant of the surface of the resin layer A in the laminate film is preferably 3.0 or more. By setting the dielectric constant to a certain level or higher, the laminate film can be imparted with appropriate conductive properties, improving antistatic properties and preventing peeling electrification and adhesion of foreign matter. The dielectric constant is the dielectric constant at a frequency of 1000 Hz, and the details of the measuring method are as shown in the Examples.

[0141] The inventors also discovered that there is a roughly inverse correlation between the dielectric constant and the surface resistivity, leading to the completion of the present invention. That is, as the dielectric constant decreases, the surface resistivity increases. Therefore, by providing low dielectric constant characteristics by setting the dielectric constant below a certain level as described above, it is possible to prevent malfunction of the touch panel in, for example, an all-in-one image display device. Furthermore, as the dielectric constant increases, the surface resistivity decreases. Therefore, by setting the dielectric constant above a certain level, the low dielectric constant characteristics become even better, and appropriate antistatic properties can be provided. The present inventors have found that the dielectric constant can be adjusted by using a thin resin layer of several to several hundred nanometers, preferably several tens of nanometers, as described above, and have thus completed the present invention. The dielectric constant can be appropriately adjusted by the thickness of the resin layer, the composition of the resin layer, the presence or absence of resin layer B, etc.

[0142] (surface resistivity of laminated film) The antistatic properties of the laminate film can be evaluated by the surface resistivity measured on the surface of resin layer A or the opposite surface of resin layer A. Note that the surface resistivity of the surface of resin layer A or the opposite surface of resin layer A referred to here is measured when no pressure-sensitive adhesive layer or release layer is provided on the opposite surface. Therefore, the surface resistivity of the opposite surface is the surface resistivity of the surface of resin layer B when resin layer B is provided, and is the surface resistivity of the surface of the base film without resin layer B when resin layer B is not provided. If the surface resistivity of either surface is appropriately high, the dielectric constant can be adjusted to an appropriate range. In the laminate film, the surface resistivity of either the surface of the resin layer A or the opposite surface of the resin layer A is, for example, 1×10 6 Ω or more, 5×10 8 is less than or equal to 5 x 10 6 Ω / □ or more, 1×10 8 By satisfying the above range, the antistatic property is improved and, for example, when used to protect the display screen of a touch panel in an all-in-one image display device, malfunctions are less likely to occur. In the present invention, the above-mentioned problem is solved by using a method that is usually difficult to adopt, namely, deliberately reducing the surface resistivity of a laminate film used in applications where anti-static properties are required. The surface resistivity of the surface of the resin layer A or the other surface of the opposite surface of the resin layer A may be within the above range or may be outside the above range. From the viewpoint of antistatic properties, the surface resistivity of the other surface may be, for example, 1×10 4 Ω or more, 5×10 8 less than or equal to 1×10 5 Ω / □ or more, 1×10 8 Ω / □ or less is preferable. The surface resistivity of the surface of the resin layer A or the opposite surface of the resin layer A can be measured as shown in the examples below.

[0143] <Adhesive sheet> When the laminate film of the present invention has a pressure-sensitive adhesive layer, it can be used as a pressure-sensitive adhesive sheet. For example, in each of the above embodiments, the laminate film having a pressure-sensitive adhesive layer may be formed into a pressure-sensitive adhesive sheet by further laminating a release film (hereinafter, for convenience, sometimes referred to as a "second release film") to the surface of the pressure-sensitive adhesive layer. The second release film may be a conventionally known release film, and may be a release paper having a paper substrate with a release treatment applied to at least one surface thereof, or a release resin film having a release treatment applied to at least one surface thereof. However, as long as it can be easily peeled from the pressure-sensitive adhesive layer, the release treatment may be omitted as appropriate. Furthermore, the second release film may be one of those described above as the first release film.

[0144] In the present invention, the laminated films 10, 10A according to either the first embodiment or the second embodiment illustrated in Figures 1 and 2 may be made into a pressure-sensitive adhesive sheet by laminating a second release film (not shown) to the surface of the pressure-sensitive adhesive layer 12. For example, when a pressure-sensitive adhesive sheet is made by laminating a second release film to the laminated film 10A according to the second embodiment, a double-sided pressure-sensitive adhesive sheet is obtained in which a first release film and a second release film are laminated to both sides of the pressure-sensitive adhesive layer 12A. Furthermore, when a second release film is attached to the laminated film 10 of the first embodiment to form an adhesive sheet, a single-sided adhesive sheet is obtained in which the adhesive layer 12 and the second release film are laminated in this order on one side (opposite side) of the base film. The pressure-sensitive adhesive sheet is preferably used by peeling off the second release film and then laminating the exposed surface of the pressure-sensitive adhesive layer onto the surface of an adherend such as an optical member.

[0145] <<Uses and Usage>> The laminate film and pressure-sensitive adhesive sheet of the present invention may be used for optical components. For example, when the laminate film has a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer may be attached to an optical component. The laminate film attached to the optical component via the pressure-sensitive adhesive layer may be used for the purpose of protecting the optical component. The laminate film may then be peeled off from the optical component once that purpose has been achieved.

[0146] As shown in the second embodiment described above, when the laminated film has a release layer, it may be used for the purpose of protecting the adhesive layer, for example, it may be used for the purpose of protecting the adhesive layer laminated on the release layer. The laminated film can also be used to bond components constituting an optical member together. For example, when the laminated film has a release layer, the pressure-sensitive adhesive layer laminated on the release layer can be used to bond components constituting an optical member together. In this case, the pressure-sensitive adhesive layer can be used to bond the components together after being peeled off from the first release film. Furthermore, as in the above-described pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet may have an OCA pressure-sensitive adhesive sheet configuration in which both sides of the pressure-sensitive adhesive layer are sandwiched between release films. In this case, the pressure-sensitive adhesive layer may be used for bonding components together after being peeled off from the release films on both sides (first and second release films).

[0147] The optical member described above is preferably an image display device. Therefore, when the laminate film has a pressure-sensitive adhesive layer, it is preferably attached to the image display device and used for the purpose of protecting the image display device. Among them, an integrated image display device in which an image display element such as an OLED and a touch sensor are integrated is more preferable. That is, the laminate film is more preferably used for protecting an image display device in which an OLED and a touch sensor are integrated. The image display device in which the laminate film is used may be a finished product or a manufacturing intermediate. However, even if it is a manufacturing intermediate, it is preferable that an image display element such as an OLED and a touch sensor are already incorporated. In this specification, the term "image display device" also includes a manufacturing intermediate of an image display device. Furthermore, the term "integrated image display device" also includes a manufacturing intermediate in which an image display element such as an OLED and a touch sensor are already integrated. Therefore, the film may be used as a process film to be attached to an intermediate product when manufacturing an optical element such as the integrated image display device of the present invention.

[0148] More specifically, the film can be used to protect display screens, such as touch panels, from scratches during manufacturing or transporting displays, or to prevent malfunctions when touching the display screen. In particular, the film is suitable for protecting the display screen of a touch panel in an image display device (e.g., a smartphone) that integrates an OLED and a touch sensor. Furthermore, when the laminated film is a release film with an adhesive layer, the adhesive layer can be suitably used for the purpose of bonding components that constitute an image display device together. In this case, the first release film can also be used to protect the adhesive layer that bonds the components together in the image display device. Here, the components that are bonded by the adhesive layer are preferably components that constitute the above-mentioned integrated image display device. Furthermore, the above-mentioned adhesive sheet may also be used for optical components, but is preferably used for image display devices, more preferably integrated image display devices, and like the above-mentioned laminated film, may be used, for example, for bonding to integrated image display devices or for joining components that make up integrated image display devices.

[0149] The laminate film has excellent low dielectric constant characteristics. Therefore, the laminate film can prevent malfunctions even in optical components that are prone to malfunction, such as integrated image display devices. Therefore, even if the laminate film is attached to an integrated image display device or the like, operation can be checked properly. Furthermore, the laminate film has a certain level of antistatic properties, which can prevent peeling electrification, adhesion of foreign matter, and entrapment of foreign matter, making it suitable for use with optical components.

[0150] In an all-in-one image display device, a touch panel is preferably disposed on the surface side of the image display element, and the laminate film of the present invention is preferably attached to the surface side of the touch panel. The laminate film may be attached directly to the touch panel, but since a surface layer such as a polarizing element is usually laminated on the surface of the touch panel, it is preferably attached to the surface layer if such a surface layer is present.

[0151] Taking an OLED as an example, an all-in-one image display device has a touch sensor provided on an organic EL element constituting an image display element in an on-cell structure, for example, a touch sensor laminated directly on the encapsulation layer of the organic EL element. The encapsulation layer is a layer made of a sealing material that seals the organic EL element, and is laminated on the organic EL element. The encapsulation layer may be a single layer, or may be a multilayer consisting of two or more layers.

[0152] The touch sensor may be of a known type such as an electromagnetic induction type, a capacitance type, or a pressure-sensitive type, but is preferably a capacitance type. Examples of the touch sensor include, but are not limited to, touch panels made of glass films, resin films such as PET films, etc. In an all-in-one image display device, a surface layer such as a polarizing element and a protective film may be laminated on the surface side of the touch sensor as described above, but the surface layer may be omitted. A known polarizing film may be used as the polarizing element. A known resin film may be used as the protective film.

[0153] In addition, in the all-in-one image display device, a cover member may be provided on the surface side of the touch sensor. Examples of the cover member include a plastic cover and a glass cover, with a glass cover being preferred. The cover member may be adhered to the surface layer via an adhesive layer. Here, the adhesive layer may be, for example, the adhesive layer in the release film with an adhesive layer according to the second embodiment.

[0154] Furthermore, a substrate may be provided on the rear side of the organic EL element (i.e., the side opposite to the side where the touch sensor is provided), and the organic EL element may be provided on the substrate. Examples of the substrate include a glass substrate and a plastic substrate, and a plastic substrate is preferred.

[0155] A specific example of an all-in-one image display device is shown in Fig. 3. As shown in Fig. 3, the all-in-one image display device 20 may be configured by providing, in this order, a plastic substrate 21, an organic light-emitting diode (OLED) element 22, an encapsulation layer 23, a touch sensor 24, a polarizing element 25, an adhesive layer 26, and a cover glass 27, but the all-in-one image display device 20 is not limited to this configuration. Note that the adhesive layer 26 may be the adhesive layer 12A of the laminated film (for example, the release film with an adhesive layer in the second embodiment) as described above, but is not particularly limited thereto.

[0156] Next, a method for using the laminate film of the present invention will be described in more detail with reference to the method for producing the integrated image display device shown in Fig. 3. The following method of use will be described using an example in which both the laminate film according to the first embodiment and the laminate film according to the second embodiment (a release film with a pressure-sensitive adhesive layer) are used. However, it is not necessary to use both the laminate films according to the first and second embodiments; only one of them may be used, and a known laminate film may be used instead of the laminate film according to the first or second embodiment.

[0157] When manufacturing the image display device shown in FIG. 3, for example, the following steps 1 to 4 may be carried out in this order. Step 1: A step of laminating the surface of the adhesive layer 12 of the laminated film 10 onto the polarizing element 25 and transporting the laminated film 10 (see FIG. 4). Step 2: After peeling off the laminated film 10, a polarizing element 25 is attached to the surface of the adhesive layer 12A of the release film 10A with the adhesive layer (see FIG. 5). Step 3: A step of peeling off the release film 15 while leaving the pressure-sensitive adhesive layer 12A (see FIG. 6). Step 4: A step of attaching a cover glass 27 to the surface of the adhesive layer 12A (see FIG. 3).

[0158] In step 1, as shown in Fig. 4, an image display device member 30, which is an intermediate product for manufacturing an image display device, is prepared, and a laminate film 10 is bonded to a polarizing element 25 of the image display device member 30 via an adhesive layer 12. The image display device member 30 is a laminate in which the components of the image display device 20 shown in Fig. 3 are laminated except for the adhesive layer and cover glass. The laminate film 10 used in step 1 is, for example, the laminate film 10 according to the first embodiment shown in Fig. 1, and is used as a protective film. The image display device member 30 is protected by the laminate film 10, for example, during transportation.

[0159] Step 2 is a step of replacing laminated film 10 with release film 10A with an adhesive layer, as shown in Figures 4 and 5. Then, in step 3, as shown in Figure 6, release film 15 is peeled off, leaving only adhesive layer 12A on image display device member 30. Next, in step 4, cover glass 27 is bonded onto the remaining adhesive layer 12A, completing image display device 20 shown in Figure 3.

[0160] In the manufacturing method, it is preferable to check the operation of the touch sensor. The check of the operation of the touch sensor can be carried out in either step 1 or step 2. That is, the operation of the touch sensor can be checked while the laminate film 10 or the release film 10A with an adhesive layer is attached to the image display device member 30. According to the above-described operation check, there is no need to check the operation of the touch sensor in a separate process, and it is possible to use the state in which the laminate film 10 or the release film 10A with an adhesive layer is attached, thereby improving production efficiency. The manufacturer can freely select which process to check the operation in.

[0161] <<<Term Explanation>>> In the present invention, the term "film" includes the term "sheet," and the term "sheet" includes the term "film." In the present invention, when "X to Y" (X and Y are any numbers) is stated, unless otherwise specified, it means "X or more and Y or less," and also includes the meanings "preferably greater than X" or "preferably smaller than Y." Furthermore, when "X or more" (X is any number), it includes the meaning "preferably greater than X" unless otherwise specified, and when "Y or less" (Y is any number), it also includes the meaning "preferably smaller than Y" unless otherwise specified. [Example]

[0162] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples within the scope of the present invention. The measurement and evaluation methods used in the present invention are as follows.

[0163] (1) Intrinsic viscosity of polyester 1 g of polyester from which components incompatible with the polyester had been removed was precisely weighed, dissolved in 100 ml of a mixed solvent of phenol / tetrachloroethane = 50 / 50 (mass ratio), and measured at 30°C.

[0164] (2) Average particle size The polyester film was observed using a TEM (H-7650 manufactured by Hitachi, accelerating voltage 100 V), and the average particle size of 10 particles was taken as the average particle size.

[0165] (3) Resin layer thickness The surface of the resin layer was stained with RuO4 and embedded in epoxy resin. Then, ultrathin sections were prepared and stained with RuO4, and the cross-sections of the resin layer were analyzed using a transmission electron microscope (TEM) (Hitachi High-Technologies Corporation, H-7650, accelerating voltage 100 kV).

[0166] (4) Dielectric constant of the surface of resin layer A Capacitance and dielectric loss were measured in the measurement range of 10 Hz to 1 MHz using a ZM2376L / Agilent 16451B solid electrode manufactured by NF Corporation. Measurements were performed in ultra-low speed and high precision mode with n=2 for each sample, and the dielectric constant at 1000 Hz was calculated.

[0167] (5) Surface resistivity of laminated film Using a four-point ESP probe in a low resistivity meter ("Loresta GPMCP-T600" manufactured by Nitto Seiko Analytech Co., Ltd.), the film samples obtained in the examples and comparative examples were conditioned for 30 minutes in a measurement atmosphere of 23°C and 50% RH, and then the surface resistance value of the resin layer A surface was measured to determine the surface resistivity. Note that the upper measurement limit of the low resistivity meter (1 × 10 8 If the resistivity exceeded the specified value (Ω / □), it is expressed as "OVER." The surface resistivity was measured on the surface of resin layer A of the film before the adhesive layer and release layer were laminated, and on the side opposite resin layer A (in this example and comparative example, the surface of resin layer B).

[0168] The polyester raw materials used in the examples and comparative examples are as follows:

[0169] <Method for producing polyester (1)> Starting materials were 100 parts by mass of dimethyl terephthalate and 55 parts by mass of ethylene glycol. 0.04 parts by mass of magnesium acetate tetrahydrate was added to the reactor as a catalyst. The reaction was initiated at 150°C. As methanol was distilled off, the reaction temperature was gradually increased to 230°C after 3 hours. After 4 hours, the transesterification reaction was essentially complete. 0.02 parts by mass of ethyl acid phosphate was added to the reaction mixture, followed by 0.04 parts by mass of antimony trioxide. The polycondensation reaction was carried out for 4 hours. The temperature was gradually increased from 230°C to 280°C. Meanwhile, the pressure was gradually reduced from atmospheric pressure to a final value of 0.3 mmHg. After the start of the reaction, the reaction was terminated at a point corresponding to an intrinsic viscosity of 0.65 dL / g due to changes in the stirring power of the reactor. The polymer was discharged under nitrogen pressure, yielding polyester (1) with an intrinsic viscosity of 0.65 dL / g.

[0170] <Method for producing polyester (2)> The starting materials were 100 parts by mass of dimethyl terephthalate and 45 parts by mass of ethylene glycol. 0.06 parts by mass of magnesium acetate tetrahydrate was added to the reactor as a catalyst. The reaction was initiated at 150°C and gradually increased to 230°C after 3 hours as methanol was distilled off. After 4 hours, the transesterification reaction was essentially complete. 0.03 parts by mass of ethyl acid phosphate was added to the reaction mixture, followed by 0.3 parts by mass of silica particles with an average particle size of 2.7 μm dispersed in ethylene glycol and 0.03 parts by mass of antimony trioxide. The polycondensation reaction was carried out for 4 hours. The temperature was gradually increased from 230°C to 280°C. Meanwhile, the pressure was gradually reduced from atmospheric pressure to a final value of 0.3 mmHg. Due to changes in the stirring power of the reactor, the reaction was terminated at a point corresponding to an intrinsic viscosity of 0.65 dL / g. The polymer was discharged under nitrogen pressure, yielding polyester (2) with an intrinsic viscosity of 0.65 dL / g.

[0171] The following resin composition was used to form the resin layer.

[0172] conductive polymer compound (A1): A conductive agent (Orgacon ICP1010 manufactured by Agfa-Gevaert) made of polyethylenedioxythiophene and polystyrene sulfonic acid, neutralized with concentrated aqueous ammonia to a pH of 9. (A2): Polyaniline sulfonic acid (manufactured by Mitsubishi Chemical Corporation, aqua-PA SS, main repeating unit: methoxy-substituted aminobenzenesulfonic acid)

[0173] binder resin (B1): Aqueous dispersion of polyester resin polymerized with the following composition When (C1a) is a polyester polyol containing 282 parts by mass of terephthalic acid, 282 parts by mass of isophthalic acid, 62 parts by mass of ethylene glycol, and 250 parts by mass of neopentyl glycol, this dispersion is obtained by neutralizing a polyester polyurethane containing 876 parts by mass of (C1a), 244 parts by mass of tolylene diisocyanate, 81 parts by mass of ethylene glycol, and 67 parts by mass of dimethylolpropionic acid with ammonia and dispersing it in water (non-volatile content concentration 20%, viscosity at 25°C 50 mPa s). (B2): Aqueous dispersion of urethane acrylate resin polymerized with the following composition Urethane acrylate consisting of hydrogenated xylylene diisocyanate, (di)pentaerythritol acrylate, poly(1,6-hexylene) carbonate, and dimethylolpropanoic acid

[0174] Polyglycerin and / or alkylene oxide adducts of polyglycerin (C1): A compound in which an average of four polyethylene oxide molecules are added to a polyglycerin skeleton in which the average n=2 in the formula (3). [ka] (C2): Polyglycerol in which the average n is 2 in the formula (3).

[0175] (D1) Nonionic surfactants A nonionic surfactant having a structure having polyethylene oxide in the side chain, in which the average of m+n is 10 in the following formula (5): [ka] (D2) Fluorine-based surfactants A fluorine-based nonionic surfactant with a structure that has a branched perfluoroalkenyl group in the hydrophobic group and a polyethylene oxide chain (average chain length 8 units) in the hydrophilic group.

[0176] (E) Particle Silica particles with an average particle size of 65 nm

[0177] Example 1 An 82 / 18 mass ratio blend of polyester (1) and polyester (2) was used as the raw material for Layer A, and polyester (1) alone was used as the raw material for Layer B. These were fed into an extruder, heated and melted at 285°C, and co-extruded to form a two-type, three-layer (A / B / A) structure with Layer A split into two to form the outermost layer (surface layer) and Layer B as the middle layer, with a thickness composition ratio of A / B / A = 5 / 90 / 5 under extrusion conditions. The film was then cooled and solidified while in close contact with a mirror-finished cooling drum at a surface temperature of 40-50°C to produce an unstretched polyethylene terephthalate film. The silica content in Layer A (surface layer) of the polyester film was 0.05 mass%. This film was stretched 3.7 times in the longitudinal direction while passing through a group of heated rolls at 85°C to obtain a uniaxially stretched film. Resin compositions 1 and 2 (coating solutions 1 and 2) shown in Table 1 below were applied to both sides of this uniaxially stretched film, and then the film was introduced into a tenter stretching machine, stretched 4.3 times in the width direction at 100°C, further heat-treated at 230°C, and then relaxed 2% in the width direction to obtain a 50µm-thick biaxially stretched polyester film having a resin layer A with a thickness (after drying) of 80nm and a resin layer B with a thickness (after drying) of 30nm.

[0178] Next, a pressure-sensitive adhesive layer composed of the following pressure-sensitive adhesive composition was applied onto resin layer B to a thickness (wet state) of 2 mil (=approximately 51 μm) and dried to obtain a laminated film. (Adhesive composition) Main ingredient: 100 parts by mass of acrylic resin (acrylic acid ester copolymer obtained by random copolymerization of butyl acrylate (59 mol%), 2-ethylhexyl acrylate (36 mol%), and 2-hydroxyethyl methacrylate (5 mol%), weight average molecular weight: 1,180,000, solid content: 41 mass%) Hardener: Takenate D-101E (Mitsui Chemicals, Inc.) 50 parts by weight Ethyl acetate: 50 parts by mass In the obtained laminated film, the dielectric constant at 1000 Hz was 3.5 on the surface of resin layer A. The properties of this film are shown in Table 2 below.

[0179] Examples 2 and 3 A laminated film was obtained in the same manner as in Example 1, except that the resin composition was changed to the composition shown in Table 1. The results are shown in Table 2.

[0180] Example 4 An 82 / 18 mass blend of polyester (1) and polyester (2) was used as the raw material for Layer A, and polyester (1) alone was used as the raw material for Layer B. These were fed into an extruder, heated and melted at 285°C, and co-extruded to a thickness ratio of A / B / A = 5 / 90 / 5, with Layer A split into two and Layer B as the outermost layer (surface layer) and Layer B as the middle layer. The resulting extrusion was then cooled and solidified while in close contact with a mirror-finished cooling drum at a surface temperature of 40-50°C to produce an unstretched polyethylene terephthalate film. This film was stretched 3.7 times in the longitudinal direction while passing through a group of heated rolls at 85°C to produce a uniaxially oriented film. Resin compositions 1 and 2 shown in Table 1 below were applied to both sides of this uniaxially stretched film, and then the film was introduced into a tenter stretching machine and stretched 4.3 times in the width direction at 100°C.Furthermore, it was heat-treated at 230°C, and then subjected to a 2% relaxation treatment in the width direction to obtain a 50 μm thick biaxially stretched polyester film having a resin layer A with a thickness (after drying) of 80 nm and a resin layer B with a thickness (after drying) of 30 nm.

[0181] Next, a release layer composed of the following release layer composition was formed on the resin layer B to a thickness (after drying) of 0.1 g / m 2 A release film was obtained by applying the coating to the film. (Release Layer Composition) Curable silicone resin (X-62-5039, manufactured by Shin-Etsu Chemical Co., Ltd.): 80 parts by weight Curable silicone resin (KS-3800 manufactured by Shin-Etsu Chemical Co., Ltd.): 20 parts by weight Curing agent (curing catalyst) (Shin-Etsu Chemical Co., Ltd. PL-5000): 2 parts by weight Solvent: 600 parts by mass of toluene, 600 parts by mass of MEK, and 600 parts by mass of hexane The obtained release film had a dielectric constant of 3.5 at 1000 Hz on the surface of resin layer A. The properties of this film are shown in Table 2 below.

[0182] Examples 5 to 6 and Comparative Examples 1 to 3 A release film was obtained in the same manner as in Example 1, except that the resin composition was changed to the composition shown in Table 1. The results are shown in Table 2.

[0183] [Table 1] Each value in Table 1 is in parts by mass based on non-volatile components.

[0184] [Table 2] *The types of resin layers A and B refer to the types of coating liquid (resin composition).

[0185] From the results shown in Table 2, it can be seen that the dielectric constant of the surface of resin layer A of the laminated film of each example satisfies the requirement of 5.5 or less, and when used to protect the display screen of an image display device (e.g., a smartphone) that integrates an OLED and a touch sensor, or to protect the adhesive layer that bonds components mounted on the image display device, it is expected that there will be a low risk of malfunction and a low risk of foreign matter adhesion. On the other hand, in each comparative example, the dielectric constant was outside the desired range, and therefore, when used to protect the display screen of an image display device (e.g., a smartphone) that integrates an OLED and a touch sensor, or to protect the adhesive layer that bonds components mounted on the image display device, there is a high risk of malfunction. Furthermore, the present invention is characterized by the discovery that there is a good correlation between dielectric constant and surface resistivity, and that if the surface resistivity is too high, i.e., if the value is too small, the risk of malfunction increases. Therefore, the present invention was completed using a technical idea that goes against conventional thinking, namely, by deliberately designing a device with reduced performance and using a thin resin layer to adjust the dielectric constant to the desired range. [Explanation of symbols]

[0186] 10, 10A laminated film 11 Base film 12, 12A, 26 adhesive layer 13 Release layer 15 Release film 20 Image display device 21 Plastic substrate 22 Organic Light Emitting Diode (OLED) 23 Encapsulated Lason Formation 24 Touch Sensor 25 Polarizing element 27 Coverslip 30 Image display device components A Resin layer A B Resin layer B

Claims

1. a base film; a resin layer A containing a conductive polymer compound and a binder resin on one surface of the base film; a resin layer B containing a binder resin on the other surface of the base film; and a pressure-sensitive adhesive layer or a release layer and a pressure-sensitive adhesive layer on the resin layer B in this order; the pressure-sensitive adhesive layer is made of a pressure-sensitive adhesive that does not have antistatic properties, A laminated film, wherein the content of the binder resin in the resin layer A is 45 to 95% by mass, the dielectric constant of the surface of the resin layer A at a frequency of 1000 Hz is 5.5 or less, the resin layer B further contains a conductive polymer compound, the content of the binder resin in the resin layer B is 45 to 95% by mass, and the surface resistivity of either the surface of the resin layer A or the surface of the resin layer B is 1 x 10 6 (Ω / □) or more and 5 x 10 8 (Ω / □) or less.

2. 2. The laminated film according to claim 1, wherein the conductive polymer compound in the resin layer B comprises a polymer obtained by doping a compound made of thiophene or a thiophene derivative with another anionic compound.

3. 2. The laminate film according to claim 1, wherein the resin layer B contains one or more compounds selected from the group consisting of polyglycerin and alkylene oxide adducts of polyglycerin, or derivatives thereof.

4. 4. The laminate film according to claim 3, wherein the one or more compounds or derivatives thereof selected from polyglycerin and alkylene oxide adducts of polyglycerin in the resin layer B are polyglycerin represented by the following general formula (3): 【Chemistry 1】 (n is an integer ranging from 2 to 20.)

5. 4. The laminate film according to claim 3, wherein the content of one or more compounds selected from polyglycerin and alkylene oxide adducts of polyglycerin or derivatives thereof in the resin layer B is 0 to 60% by mass.

6. The laminated film according to claim 1 , wherein the resin layer B does not contain a crosslinking agent.

7. The laminated film according to claim 1 , wherein the resin layer B contains two types of conductive polymer compounds.

8. 8. The laminated film according to claim 7, wherein the two types of conductive polymer compounds in the resin layer B are a polymer obtained by doping a compound made of thiophene or a thiophene derivative with another anionic compound, and a polyaniline compound.

Images