Laminated film, adhesive sheet, and method for using same

Abstract

A laminated film 10A includes: a base film 11; a resin layer A provided on one side of the base film 11 and containing a conductive polymer compound and a binder resin; and at least one of an adhesive layer 12A and a release layer 13 provided on the opposite side of the base film 11. In the laminated film 10A, the content of the binder resin in the resin layer A is 45 mass% 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

Laminated films, adhesive sheets, and methods for using the same.

[0001] The present invention relates to laminated films, adhesive sheets, and methods for using the same.

[0002] Polyester film possesses excellent properties such as mechanical strength, dimensional stability, flatness, heat resistance, chemical resistance, and optical properties, and is cost-effective, making it suitable for a wide range of applications.

[0003] Polyester film is sometimes used for surface protection of components such as displays and touch panels.

[0004] In recent years, the mainstream type of display has been the one where the touch sensor is located near the OLED, a so-called integrated OLED and touch sensor type. This integrated type is called by various names depending on the panel manufacturer, such as Y-OCTA (YOUM on-cell touch AMOLED), ToE (touch on encapsulation), or FMLOC (flexible multi-layer on cell touch). Although the integrated type is more difficult to manufacture than the type where the touch sensor is encapsulated on the OLED, it has the advantage of allowing for thinner panels and is expected to reduce manufacturing costs.

[0005] On the other hand, polarizing films equipped with an adhesive layer having antistatic properties have been proposed from the perspective of preventing malfunctions of touch panels. (Patent Document 1) Furthermore, there are disclosures relating the sensitivity of touch panels to the dielectric constant. (Patent Documents 2, 3)

[0006] Japanese Patent Publication No. 2018-165389, Japanese Patent Publication No. 2014-205244, Japanese Patent Publication No. 2016-216691

[0007] However, with the aforementioned change to an integrated panel structure, conventional antistatic surface protection films or release films may have excessive conductivity, potentially causing malfunctions. For example, a surface protection film consisting of a resin layer (antistatic layer), a base film, and an adhesive layer can be attached to the screen of an integrated image display device (e.g., a smartphone) that integrates an OLED and a touch sensor, and the display screen's performance can be checked by touching it with a fingertip. In this case, if the conductivity of the surface protection film used is too good, malfunctions may occur. On the other hand, if the conductivity is reduced, problems such as the adhesion of foreign matter or static charge due to delamination may occur during the manufacturing process.

[0008] Therefore, the present invention has been made in view of the above problems, and its object is to provide a laminated film that is less prone to malfunction and has appropriate conductive properties for use as protection for an integrated image display device in which an image display element such as an OLED and a touch sensor are integrated.

[0009] In view of the above problems, the inventors have conducted extensive research and, as a result, have considered the conductive performance from the operating principle of the touch sensor, and have determined the antistatic performance of the surface protective film or release film by its dielectric constant. They have found that by setting the dielectric constant within a specific range in a laminated film having a specific configuration, it is possible to prevent malfunctions of the above-mentioned OLED and touch sensor integrated image display device (for example, a smartphone), and have completed the present invention. That is, the present invention provides the following embodiments [1] to

[33] .

[0010] [1] A laminated film 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 an 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% 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 [1], wherein the base film is a polyester film. [3] The laminated film according to [1] or [2], wherein the conductive polymer compound comprises a polymer obtained by doping a compound consisting of thiophene or a thiophene derivative with another anionic compound. [4] The laminated film according to any one of [1] to [3], wherein the resin layer A contains one or more compounds selected from polyglycerin and alkylene oxide adducts to polyglycerin or derivatives thereof. [5] The laminated film according to [4], wherein one or more compounds selected from the polyglycerin and alkylene oxide adducts to the polyglycerin, or derivatives thereof, is the polyglycerin represented by the following general formula (3). (n is an integer in the range of 2 to 20.) [6] The laminated film according to any one of [1] to [5] above, wherein the content of one or more compounds selected from polyglycerin and alkylene oxide adducts to polyglycerin or derivatives thereof in the resin layer A is 0 to 60% by mass. [7] The laminated film according to any one of [1] to [6] above, 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 ６ (Ω / □) or more, 5×10 ８[1] to

[12] above, wherein the laminated film is less than or equal to (Ω / □). [9] The laminated film according to any one of [1] to [8] above, wherein the resin layer A contains two types of conductive polymer compounds.

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

[11] The laminated film according to any one of [1] to

[10] above, wherein the resin layer B containing a binder resin is provided on the opposite side of the base film.

[12] The laminated film according to

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

[13] The laminated film according to

[11] or

[12] above, 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 contains 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

[11] to

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

[16] The laminated film according to

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

[17] The laminated film according to any one of

[11] to

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

[18] The laminated film according to any one of

[11] to

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

[19] The laminated film according to any one of

[11] to

[18] above, 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 consisting of thiophene or a thiophene derivative with another anionic compound and a polyaniline compound.

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

[20] above, wherein the adhesive layer consists of an acrylic, urethane, or silicone adhesive.

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

[21] above, wherein the adhesive layer is made of an adhesive that does not have antistatic properties.

[23] The laminated film according to any one of [1] to

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

[24] The laminated film according to any one of

[11] to

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

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

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

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

[25] above, wherein the laminated film comprises the adhesive layer, and the surface of the adhesive layer of the laminated film is bonded to the surface of an optical member.

[27] The method of using the laminated film according to

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

[28] An adhesive sheet comprising a laminated film as described in any of [1] to

[25] above, and a second release film to be bonded to the adhesive layer of the laminated film.

[29] A method for using the adhesive sheet described in

[28] above, wherein after peeling off the second release film, the surface of the exposed adhesive layer is bonded to the surface of the optical member.

[30] A method for using the adhesive sheet described in

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

[31] A laminated film described in any of [1] to

[25] above for protecting an integrated image display device comprising an OLED and a touch sensor.

[32] A release film described in any of [1] to

[25] above, wherein the adhesive layer is an adhesive layer used in an integrated image display device comprising an OLED and a touch sensor, and the release film is for protecting the adhesive layer.

[33] A adhesive sheet described in

[27] above for bonding to an integrated image display device comprising an OLED and a touch sensor.

[0011] According to the laminated film of the present invention, by setting the dielectric constant of the resin layer A to a specific range, low dielectric constant characteristics can be achieved even when a general-purpose adhesive layer or release layer is provided. Therefore, it can be suitably used, for example, for protecting an integrated image display device that combines an OLED and a touch sensor, or for protecting the adhesive layer that joins components mounted on the above-mentioned integrated image display device.

[0012] This is a schematic cross-sectional view showing a laminated film according to the first embodiment. This is a schematic cross-sectional view showing a laminated film according to the second embodiment. This is a schematic cross-sectional view showing an example of an integrated image display device. This is a schematic cross-sectional view showing one step in the manufacturing method of an integrated image display device. This is a schematic cross-sectional view showing one step in the manufacturing method of an integrated image display device. This is a schematic cross-sectional view showing one step in the manufacturing method of an integrated image display device.

[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 embodiments described below, and can be modified and implemented as such without departing from the spirit of the invention.

[0014] <<<Laminated Film>>> The laminated film of the present invention comprises 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 an adhesive layer and a release layer on the opposite surface of the base film, wherein the binder resin content 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.

[0015] <<Base Film>> The base film is not limited in material 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 base films include films formed by creating a film of polymers such as polyethylene, polypropylene, polyester, polystyrene, polycarbonate, polyethersulfone, polyamide, and polyimide. Furthermore, if it is possible to form a film, it may also be a mixture of these materials (i.e., a polymer blend) or a composite of constituent units (e.g., a copolymer). Among the films exemplified above, polyester film is particularly preferred because it has excellent physical properties such as heat resistance, flatness, optical properties, and strength. The following will explain in detail using the case where the base film is a polyester film as an example, but since resin films other than polyester film have the same composition as polyester film except for the resin, their explanation will be omitted.

[0016] <<Polyester Film>> The polyester film used as the base 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 even four or more layers, as long as it does not deviate from the gist of the present invention, and the number of layers is not particularly limited. Furthermore, the polyester film may be unstretched, uniaxially oriented, or biaxially oriented, but a biaxially oriented polyester film is preferred in terms of thinness and dimensional stability.

[0017] The polyester used for the polyester film may be a homopolyester or a copolyester. When it consists of a homopolyester, those obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic glycol are preferred. Examples of the aromatic dicarboxylic acid include naphthalenedicarboxylic acids such as terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of the aliphatic glycol include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. Representative polyesters include polyethylene terephthalate. On the other hand, examples of the dicarboxylic acid component of the copolyester include one or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid, and examples of the glycol component include one or more of ethylene glycol, diethylene glycol, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2,2-isopropyl-1,3-propanediol, 2,2-di-n-1,3-propanediol, etc., such as propylene glycol, 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, still more preferably 0.56 to 0.80 gL / g, and even more preferably 0.6 to 0.75 dL / g.

[0019] There is no particular limitation on the polymerization catalyst for the polyester, and conventionally known compounds can be used. Examples include titanium compounds, germanium compounds, antimony compounds, manganese compounds, aluminum compounds, magnesium compounds, and calcium compounds.

[0020] As will be described later, for example, the polyester film is suitable for the protective film described later, and depending on the conditions of various processes, oligomer components may precipitate from the polyester film due to heating, which may cause contamination of the product. In order to suppress the precipitation amount of the oligomer components, a film may be manufactured using a polyester with a low content of oligomer components as a raw material. As a method for producing a polyester with a low content of oligomer components, various known methods can be used, such as a method of subjecting the polyester to solid-phase polymerization after production. Further, the polyester film may have a three-layer or more structure, and the outermost layer (surface layer) of the polyester film may be a layer using a polyester raw material with a low content of oligomer components, thereby suppressing the precipitation amount of the oligomer components. Further, the polyester may be obtained by subjecting it to an esterification or transesterification reaction and then further increasing the reaction temperature and performing melt polycondensation under reduced pressure.

[0021] It is also possible to contain an ultraviolet absorber in the polyester film in order to improve the weather resistance of the film and prevent deterioration of the adherend and the like. The ultraviolet absorber is a compound that absorbs ultraviolet rays and is not particularly limited as long as it can withstand the heat added in the manufacturing process of the polyester film.

[0022] As the ultraviolet absorber, there are organic ultraviolet absorbers and inorganic ultraviolet absorbers, but from the viewpoint of transparency, organic ultraviolet absorbers are preferred. The organic ultraviolet absorber is not particularly limited, and examples thereof include cyclic iminoester-based, benzotriazole-based, benzophenone-based, and the like. From the viewpoint of durability, cyclic iminoester-based and benzotriazole-based are more preferred. It is also possible to use two or more kinds of ultraviolet absorbers in combination.

[0023] Polyester films may be designed without particles to improve transparency, or they may be designed with particles primarily for the purpose of providing slipperiness and preventing scratches during each process. When particles are incorporated, the type of particles is not particularly limited as long as they can provide slipperiness. 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 dioxide, 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 metal compounds such as catalysts during the polyester manufacturing process can also be used.

[0024] When incorporating particles, there are no particular restrictions on their shape; they can be spherical, lumpy, rod-shaped, flattened, or any other form. Furthermore, there are no particular restrictions 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, their 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 preferable because it prevents the film's surface roughness from becoming too rough, thus reducing the likelihood of problems when forming various surface functional layers in subsequent processes. A particle size of 0.01 μm or more is preferable 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 taking the average value of the particle sizes of 10 particles as the average particle size.

[0026] Furthermore, the particle content in the polyester film is usually less than 5% by mass, preferably less than 3% by mass. A particle content of less than 5% by mass makes it easier to ensure the transparency of the film. 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 contains particles, it is preferable to contain the particles in the single layer with the above-mentioned particle content. When containing particles, for example, it is preferable to provide a surface layer and an intermediate layer, and to contain the 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 be within the above-mentioned particle content range. Therefore, it is preferable that the particle content on the surface of the polyester film is within the above range.

[0027] The method for incorporating particles into a polyester film is not particularly limited, and conventionally known methods can be employed. For example, in the case of a multilayer 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 them after the esterification or transesterification reaction is completed.

[0028] In addition to the UV absorber and particles mentioned above, conventionally known antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments, etc., may be added to the polyester film as needed. It is preferable that these additives do not contain fluorine components.

[0029] The thickness of the polyester film is not particularly limited as long as it is within the range that allows it to be formed as a film, but it 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 content 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 0.1%.

[0031] Next, a specific example of polyester film production will be described, but the production method is not limited to the following example. For example, when producing a biaxially oriented polyester film, it is preferable to extrude the dried pellets of the polyester raw material mentioned above from a die using an extruder as a molten sheet, and then cool and solidify them with cooling rolls such as a rotating cooling drum to obtain an unstretched sheet. In this case, it is preferable to improve the adhesion between the sheet and the rotating cooling drum in order to improve the flatness of the sheet, and electrostatic application adhesion and / or liquid coating adhesion methods are preferably employed. Next, the obtained unstretched sheet is stretched in the biaxial direction. In this case, first, the unstretched sheet is stretched in one direction using a roll or tenter type stretcher. 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, it is stretched in a direction perpendicular to the first stretching direction, in which case the stretching temperature is usually 70 to 170°C, and the stretching ratio is usually 3.0 to 7 times, preferably 3.5 to 6 times. Then, the film is heat-treated at a temperature of typically 180 to 270°C under tension or under relaxation of 30% or less to obtain a biaxially oriented film. In the stretching described above, a method of stretching in one direction in two or more stages can also be employed. In that case, it is preferable to ensure that the final stretching ratios in both directions are within the above ranges.

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

[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 the base film. The resin layer A 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 the resin layer A. The resin layer A of the base film of the present invention must contain a conductive polymer compound and a binder resin.

[0034] Resin layer A, i.e., resin composition A, has a conductive polymer compound and a binder resin as essential components, and may also contain polyglycerin-based compounds as described later, and it is more preferable that it contains a conductive polymer compound, a polyglycerin-based compound and a binder resin. It can be inferred that unreacted compounds, reacted compounds, or mixtures thereof of the various compounds of resin composition A are present in resin layer A.

[0035] (Conductive polymer compound) The resin layer A contains a conductive polymer compound to exhibit low dielectric constant properties. This conductive polymer compound is suitable from the viewpoint of recent PFAS regulations, for example, because 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 compounds") obtained by doping a compound consisting of thiophene or a thiophene derivative with other anionic compounds. Examples of thiophene compounds include those obtained by polymerizing the compound of formula (1) or (2) below in the presence of a polyanion. Furthermore, the above-mentioned thiophene compounds may be obtained by using different polymers having a thiophene skeleton in combination.

[0037]

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

[0039]

[0040] In equation (2) above, n represents an integer from 1 to 4.

[0041] Examples of polyanions used in the polymerization of polymers include poly(meth)acrylic acid, polymaleic acid, polystyrene sulfonic acid, and polyvinyl sulfonic acid. As a method for producing such polymers, for example, the method described in Japanese Patent Publication No. 7-90060 can be employed. As for the thiophene compound, a compound of formula (2) above in which n is 2 and polystyrene sulfonic acid is used as the polyanion is preferably used.

[0042] Furthermore, if these polyanions are acidic, some or all of them may be neutralized. Ammonia, organic amines, and alkali metal hydroxides are preferred bases for neutralization.

[0043] Furthermore, conductive polymer compounds other than thiophene compounds may be used; for example, polyaniline compounds may be used. The polyaniline compounds used are those having a polyaniline skeleton, and it is preferable that the main repeating unit is an alkoxy-substituted aminobenzenesulfonic acid that is conductive. While there are no particular restrictions on the alkoxy group as long as it is a lower alkoxy group, a methoxy group is preferred in terms of cost and performance. In the present invention, it is preferable that substantially all aromatic rings in the polyaniline skeleton contain sulfonic acid groups and alkoxy groups, but there are no particular restrictions on the inclusion of compounds lacking one or both substituents, or having other substituents. The number-average molecular weight of the conductive polyaniline compound, whose main repeating unit is an alkoxy-substituted aminobenzenesulfonic acid, is not particularly limited, but is preferably 5000 to 20000. A number-average molecular weight of 5000 or more is advantageous for constructing a conductive network. On the other hand, a number-average molecular weight of 20000 or less prevents excessive viscosity and provides good coating properties. The number-average molecular weight of the polyaniline compounds was measured by gel permeation chromatography (GPC).

[0044] Polyaniline compounds having alkoxy-substituted aminobenzenesulfonic acid as the main repeating unit and possessing conductivity are generally highly acidic, and therefore it is possible and preferable to use them after adjusting the pH with a basic compound. Preferred basic compounds include ammonia and organic amines, with ammonia being more preferred.

[0045] In this invention, from the viewpoint of adjusting 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-based compound and a polyaniline compound is exemplified. By adjusting the mixing ratio of the two, it is possible to easily adjust the dielectric constant to a desired range.

[0046] (Binder Resin) Resin layer A, that is, resin layer composition A, contains a binder resin. By containing a binder resin, resin layer A can be given film-forming properties. It can also improve the coating appearance and transparency. The binder resin is preferably a polymer compound with a number-average molecular weight (Mn) of 1000 or more, as measured by gel permeation chromatography (GPC). Various conventionally known polymers, such as polyester resin, acrylic resin, and urethane resin, can be used as the binder resin. These may be used individually or in combination of two or more. Among these binder resins, it is preferable to use urethane resin from the viewpoint of coating appearance, and among them, urethane acrylate resin is more preferable. Furthermore, these binder resins can also be used as the binder resin for resin layer B, which will be described later. When used as the binder resin for resin layer B, the adhesion to the adhesive layer can be improved by using urethane resin, especially urethane acrylate resin.

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

[0048] Polycarbonate polyols are obtained from polyhydric alcohols and carbonate compounds by a de-alcoholization reaction. 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. Examples of polycarbonate-based polyols obtained from the reactions of these include poly(1,6-hexylene) carbonate and poly(3-methyl-1,5-pentylene) carbonate.

[0049] Polyester polyols include polyhydric 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 Examples include those obtained from the reaction of (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. Specifically, examples include trimethylolpropane-based acrylates such as trimethylolpropane mono(meth)acrylate, ditrimethylolpropane mono(meth)acrylate, ditrimethylolpropane di(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, pentaerythritol-based acrylates such as pentaerythritol mono(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol mono(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol acrylates such as dipentaerythritol tetra(meth)acrylate, tripentaerythritol-based acrylates, and tetrapentaerythritol (meth)acrylate.

[0052] Polyisocyanates that make up urethane resins include, for example, aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylenediphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, and tolidine diisocyanate; aliphatic diisocyanates having aromatic rings such as α,α,α',α'-tetramethylxylylene diisocyanate; methylene diisocyanate; propylene diisocyanate; and lysine diisocyanate. Examples include aliphatic diisocyanates such as socyanates, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate, and alicyclic diisocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylenebis(4-cyclohexyl isocyanate), dicyclohexylmethane diisocyanate, isopropylidene dicyclohexyl diisocyanate, and hydrogenated xylylene diisocyanate. These may be used individually or in combination, and these polyisocyanate compounds may be in the form of dimers, trimers represented by isocyanuric rings, or polymers of more than one type. Furthermore, among the above isocyanates, aliphatic or alicyclic isocyanates are more preferred than aromatic isocyanates in terms of improving adhesion to active energy ray curable coatings and preventing yellowing due to ultraviolet light.

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

[0054] Examples of chain extenders having two hydroxyl groups include glycols such as aliphatic glycols like ethylene glycol, propylene glycol, butanediol, and pentanediol; aromatic glycols like xylylene glycol and bishydroxyethoxybenzene; and ester glycols like neopentyl glycol and neopentyl glycol hydroxypivalate. Furthermore, 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, isopropylthincyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, 1,3-bisaminomethylcyclohexane, and isophoronediamine.

[0055] The urethane resin contained in resin layer A may use a solvent as a medium, but preferably water is used. Methods for dispersing or dissolving the urethane resin in water include forced emulsification using an emulsifier, self-emulsification by introducing hydrophilic groups into the urethane resin, or water-soluble methods. In particular, the self-emulsification type, in which ionic groups are introduced into the urethane resin skeleton to form an ionomer, is preferred due to its excellent storage stability of the liquid and superior water resistance, transparency, and adhesion of the resulting coated layer. Various ionic groups can be introduced, such as carboxyl groups, sulfonic acids, phosphoric acid, phosphonic acid, and quaternary ammonium salts, but carboxyl groups are preferred. Various methods can be used to introduce carboxyl groups into the urethane resin at each stage of the polymerization reaction. For example, a resin containing carboxyl groups can be used as a copolymer component during prepolymer synthesis, or a component containing carboxyl groups can be used as one component of a polyol, polyisocyanate, or chain extender. In particular, a method using a carboxyl group-containing diol to introduce a desired amount of carboxyl groups by adjusting the amount of this component added is preferred. For example, dimethylolpropionic acid, dimethylolbutanoic acid, bis-(2-hydroxyethyl)propionic acid, bis-(2-hydroxyethyl)butanoic acid, etc., can be copolymerized with the diol used in the polymerization of the urethane resin. Furthermore, it is preferable that the carboxyl group be in the form of a salt obtained by neutralizing it with ammonia, amines, alkali metals, inorganic alkalis, etc. Particularly preferred are ammonia, trimethylamine, and triethylamine. From the viewpoint of improving adhesion, the urethane resin is preferably a urethane resin containing a carbon-carbon double bond, more preferably polycarbonate polyols or polyester polyols and containing a carbon-carbon double bond, and particularly preferably polycarbonate polyols and containing a carbon-carbon double bond.

[0056] A urethane resin containing a carbon-carbon double bond is a urethane resin that has a carbon-carbon double bond within it, and conventionally known materials can be used. For example, this can be done by introducing acrylate groups, methacrylate groups, vinyl groups, allyl groups, etc., into the urethane resin.

[0057] Various substituents can be introduced to the carbon-carbon double bond, such as alkyl groups like methyl or ethyl groups, phenyl groups, halogen groups, ester groups, amide groups, or even structures like conjugated double bonds. There are no particular restrictions on the amount of substituent; monosubstituted, disubstituted, trisubstituted, or tetrasubstituted compounds can all be used. Considering reactivity, monosubstituted or disubstituted compounds are preferred, and monosubstituted compounds are even more preferred.

[0058] From the viewpoint of ease of introduction into urethane resin and adhesion to the adhesive layer, acrylate groups and methacrylate groups are preferred, unsubstituted acrylate groups and methacrylate groups are more preferred, and unsubstituted acrylate groups are particularly preferred. As a urethane resin into which acrylate groups and methacrylate groups have been introduced, the above-mentioned urethane acrylate resin is preferred.

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

[0060]

[0061] The value of n in formula (3) above 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. Using a value within this range makes it easier to obtain a good coating appearance, antistatic properties, and durability of the resin layer.

[0062] An alkylene oxide adduct to polyglycerin is a structure having been obtained by addition polymerization of alkylene oxide to the hydroxyl group of polyglycerin represented by general formula (3).

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

[0064] The preferred alkylene oxide to be added to polyglycerin is ethylene oxide or propylene oxide. Of these, ethylene oxide is preferred. Furthermore, the number of added atoms is preferably in the range of 200 to 5000 in terms of the number-average molecular weight of the final compound. By keeping the alkylene chain of the alkylene oxide below a certain length, it is possible to prevent increased hydrophobicity and deterioration of dispersibility in the coating solution, and the antistatic properties and transparency of resin layer A tend to decrease, so it is preferable to adjust the chain length with this in mind.

[0065] Examples of polyglycerin or derivatives of alkylene oxide adducts to 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, as well as 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, which are added to polyglycerin or polyglycerin. The above-mentioned polyglycerin or alkylene oxide adducts to polyglycerin or derivatives thereof may be used individually or in combination of two or more types.

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

[0067] Polyaniline compounds may be used as the conductive polymer compound. In this case, the content of the polyaniline compound in 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] Furthermore, when using polyaniline compounds, they may be used in combination with thiophene compounds as described above. In this case, the content of the thiophene compound in 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 becomes easier to adjust the dielectric constant to the desired range.

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

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

[0071] When resin layer A contains a polyglycerin-based compound, the ratio of the content of the polyglycerin-based compound in resin layer A to the content of the conductive polymer compound in resin layer A (content of polyglycerin-based compound / content of 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 resin layer A to the content of the binder resin in resin layer A (content of conductive polymer compound / content of 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 resin layer A, or resin composition A, does not contain a crosslinking agent. By not containing a crosslinking agent, the dispersibility of conductive compounds is improved, making it easier to secure the desired dielectric properties and antistatic performance. A crosslinking agent is a component that crosslinks the binder resin, and is a component other than the binder resin mentioned above. Not containing a crosslinking agent means that no crosslinking agent is blended into resin composition A, and that resin layer A is a resin layer that is not crosslinked by a crosslinking agent. Examples of crosslinking agents 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 resin layer A can be improved by having the binder resin play a crosslinking agent-like role.

[0074] Furthermore, resin layer A, i.e., resin composition A, may contain additives other than those mentioned above, for example, surfactants. By using surfactants, the dispersibility of each component in resin layer A can be improved. Examples of surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. The surfactant content in 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. In addition, resin layer A, i.e., resin composition A, may contain additives other than surfactants, such as defoaming agents, coating properties improvers, thickeners, organic lubricants, ultraviolet absorbers, antioxidants, foaming agents, dyes, pigments, etc. The content of each component in resin layer A as described above can also be said to be the proportion of each component in the total nonvolatile components in resin composition A that forms resin layer A. Furthermore, the content of each component in resin layer B, which will be described later, can also be said to be the proportion of each component in the total nonvolatile components in resin composition B that forms resin layer B.

[0075] (Resin layer B) The laminated 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). In other words, the laminated 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, but another layer may be provided between the base film such as a polyester film and the resin layer B. By including resin layer B in addition to resin layer A, the laminated film can more easily obtain the desired low dielectric constant characteristics. Therefore, it is possible to improve antistatic performance while more easily preventing 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, but it is preferable that it contains a binder resin and a conductive polymer compound, and more preferably that it contains a binder resin, a conductive polymer compound and a polyglycerin-based compound. Details of the binder resin, conductive polymer compound and polyglycerin-based compound, and details of their content are as described above for resin layer A. Note that although the content was described above as the content in resin layer A, it should be read as the content 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 resin composition B does not contain a crosslinking agent, and that resin layer B is a resin layer that is not crosslinked by a crosslinking agent. Also, resin layer B, i.e., resin composition B, may contain surfactants 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 resin layer can be made lower than that of the other resin layer, 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 resin layer of resin layer A and resin layer B may be higher than the content (mass%) of the conductive polymer compound in the other resin layer. Furthermore, the type of conductive polymer compound in one resin layer may be different from that in the other resin layer. In this case, the content (mass%) of the conductive polymer compound may also be adjusted as appropriate from the viewpoint of adjusting the dielectric constant and antistatic properties. Specifically, one resin layer may contain a thiophene-based compound in a preferred content of the conductive polymer compound described above (i.e., 1 to 20% by mass, more preferably 1 to 18% by mass, even more preferably 1 to 16% by mass, and even more preferably 4 to 16% by mass), while the other resin layer may contain a thiophene-based compound and a polyaniline compound in a preferred content for combined use as described above. Furthermore, from the viewpoint of adjusting 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 is contained, it may be in a smaller amount than the content (by mass) of the polyglycerin-based compound in the other resin layer. Also, from the viewpoint of appropriately adjusting the dielectric constant, it is preferable to use a thiophene-based compound and a polyaniline compound in combination in at least one of resin layer A and resin layer B.

[0079] Analysis of various components in the resin layer can be performed by methods such as TOF-SIMS, ESCA, and X-ray fluorescence analysis.

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

[0081] <Method for Forming Resin Layers> Next, a method for forming resin layers (i.e., resin layers A and B) on a base film such as a polyester film will be described. The resin layers are formed from resin composition A or resin composition B, and specifically, they can be formed by applying resin composition A or resin composition B to the base film and drying, curing, etc., as necessary. The method of applying the resin composition is not particularly limited, and conventionally known coating methods such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, curtain coating, etc. can be used. In addition, there are in-line coating and off-line coating as methods for forming the resin layers. The drying and curing conditions are not particularly limited, and for example, when forming a resin layer by off-line coating, it is generally preferable to perform heat treatment 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 a resin layer by in-line coating, it is generally preferable to perform heat treatment 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 is a process of treating the film surface during the film-forming process of a base film such as a polyester film. In-line coating is a method of coating within the manufacturing process of a base film such as a polyester film, and specifically, it is a method of coating at any stage from melt-extruded resin such as polyester to stretching, heat-fixing, and winding. Typically, the coating is applied to an unstretched sheet obtained by melting and rapidly cooling, a stretched uniaxially oriented film, a biaxially oriented film before heat-fixing, or a film after heat-fixing but before winding. Although not limited to the above, for example, in sequential biaxial stretching, a method in which a uniaxially oriented film stretched in the longitudinal direction (vertical direction) is coated and then stretched in the transverse direction is particularly excellent. With this method, film formation of the base film and resin layer formation can be performed simultaneously, which has advantages in terms of manufacturing costs, and because stretching is performed after coating, the thickness of the resin layer can be changed according to the stretching ratio, making thin-film coating easier compared to offline coated films. Furthermore, by providing a resin layer on the base film before stretching, the resin layer can be stretched together with the base film, thereby firmly adhering the resin layer to the base film. Moreover, for example, in the manufacture of biaxially oriented polyester film, the film can be restrained in the longitudinal and transverse directions by stretching while gripping the film edges with clips, etc., and high temperatures can be applied during the heat setting process while maintaining flatness without wrinkles. Therefore, the heat treatment applied after coating can reach temperatures that cannot be achieved by other methods, improving the film-forming properties of the resin layer, allowing for stronger adhesion between the resin layer and the base film, and furthermore, creating a stronger resin layer that improves performance such as adhesion and heat and moisture resistance with various functional layers (e.g., adhesive layers and release layers) formed on the resin layer.

[0083] When forming a resin layer by in-line coating, it is preferable to apply the resin composition, which is prepared as an aqueous solution or aqueous dispersion, to a substrate film, with a solid content concentration (total non-volatile components) of approximately 0.1 to 50% by mass.

[0084] Furthermore, regardless of whether it is offline coating or in-line coating, heat treatment and active energy ray irradiation such as ultraviolet irradiation may be used in combination as needed. The substrate film constituting the laminated film of the present invention may be subjected to a surface treatment such as corona treatment or plasma treatment in advance.

[0085] <<Adhesive Layer>> In one embodiment of the present invention (hereinafter also referred to as the "first embodiment"), an adhesive layer is provided on the opposite side of the base film (i.e., the side opposite to the side on which the resin layer A is provided). If a resin layer B is provided on the opposite side, the adhesive layer may be formed on the resin layer B.

[0086] Therefore, in the first embodiment, the laminated film 10 comprises a base film 11, a resin layer A provided on one side of the base film 11, a resin layer B provided on the opposite side of the base film 11, and an adhesive layer 12 provided on the resin layer B of the base film 11, as shown in Figure 1. The laminated film 10 having the above configuration can be suitably used, for example, as a protective film. However, the laminated film 10 according to this embodiment may have other layers, for example, a primer layer to improve 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. Also, the resin layer B may be omitted, in which case the adhesive layer 12 may be directly laminated on the opposite side 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 to form it with a slightly tacky adhesive that does not contain fluorine components and can be peeled off after being attached to the adherend. The adhesive layer may be formed with an adhesive, and examples of adhesives that can be used include acrylic adhesives, urethane adhesives, and silicone adhesives. Furthermore, any general-purpose adhesive may be used, and it is preferable that the adhesive does not contain an antistatic agent and does not have antistatic properties. Examples of antistatic agents include the conductive polymer compounds mentioned above and other 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, it 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 in order to exhibit adhesive strength with the adherend, a range of 5 to 500 μm is preferred, a range of 10 to 300 μm is more preferred, and among these, a range of 20 to 200 μm is particularly good.

[0088] (Acrylic adhesive) The acrylic adhesive can be formed from a conventionally known acrylic adhesive composition, and may be formed from an adhesive composition containing a (meth)acrylic acid ester (co)polymer, and optionally further containing a photopolymerization initiator, a crosslinking agent, a silane coupling agent, and other materials. For example, the adhesive composition described in Japanese Patent Application Publication No. 2019-210446 can be used.

[0089] (Urethane-based adhesives) Urethane-based adhesives can be formed from urethane-based adhesive compositions containing reaction products of polyols as urethane-based polymers and polyisocyanate compounds. Examples of polyol components include high-molecular-weight polyols such as polyester polyols, polyether polyols, polycarbonate polyols, and caprolactone polyols. 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-based adhesives) Silicone-based adhesives can be formed from a silicone-based adhesive composition in which silicone resin is the main component resin. The "main component resin" refers to the resin with the largest content (mass) among the resins constituting the adhesive. Examples of adhesive compositions in which silicone resin is the main component resin include addition reaction type, peroxide curing type, or condensation reaction type silicone adhesives. Among these, addition reaction type silicone adhesives are preferably used from the viewpoint of being able to cure at low temperatures and in a short time. These addition reaction type silicone adhesives form an adhesive layer on a support by curing. When an addition reaction type 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 adhesive can be cured by, if necessary, diluting a silicone resin solution with a solvent such as toluene, adding a catalyst such as a platinum catalyst, stirring until homogeneous, applying it to a support, and heating it at, for example, 100 to 130°C for about 1 to 5 minutes. If necessary, a crosslinking agent, an additive to control the adhesive strength may be added to the addition-reaction type silicone adhesive, or the base film may be treated with a primer before the formation of the adhesive layer.

[0092] Examples of commercially available silicone resins used in addition-reaction type silicone adhesives include SD4580PSA, SD4584PSA, SD4585PSA, SD4587LPSA, SD4560PSA, SD4570PSA, SD4600FCPSA, SD4593PSA, DC7651ADHESIVE, DC7652ADHESIVE, LTC-755, LTC-310 (all manufactured by Toray Dow Corning), KR-3700, KR-3701, KR-3704, X-40-3237-1, X-40-3240, Examples include X-40-3291-1, X-40-3229, X-40-3323, X-40-3306, 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, PSA-7465 (all manufactured by Arakawa Chemical Industries, Ltd.), TSR1512, TSR1516, TSR1521 (all manufactured by Momentive Performance Materials, Inc.).

[0093] <<Release Layer>> In another embodiment of the present invention (hereinafter also referred to as the "second embodiment"), a release layer is provided on the opposite side of the base film (i.e., the side opposite to the side on which the resin layer A is provided). When a resin layer B is provided on the opposite side, the release layer is preferably formed on the resin layer B. Furthermore, an adhesive layer may be provided on the release layer. Accordingly, the laminated film 10A according to the second embodiment comprises, in this order, a base film 11, a resin layer A provided on one side of the base film 11, a resin layer B provided on the opposite side of the base film 11, and a release layer 13 and an adhesive layer 12A provided on the resin layer B of the base film 11, as shown in Figure 2. The laminated film 10 having the above configuration can be used as a release film with an adhesive layer. That is, for example, a laminate consisting of layers from the resin layer A to the release layer 13 becomes a release film (hereinafter sometimes referred to as the "first release film") 15 that can be peeled off from the adhesive layer. Furthermore, the release film with the adhesive layer is preferably peeled off after the surface of the adhesive layer 12A is bonded to the adherend, and then the first release film 15 is peeled off from the adhesive layer 12A. Before being peeled off from the adhesive layer 12A, the first release film 15 is used to protect the adhesive layer. 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, but before being peeled off from the adhesive layer 12A. On the other hand, the adhesive layer remaining on the adherend after the first release film 15 has been peeled off may be used as an adhesive layer to bond the adherends together. However, the laminated film 10A according to this embodiment may have other layers, for example, a primer layer to improve 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 side of the base film 11. Moreover, in the second embodiment having a release layer, the laminated film may be one in which the adhesive layer 12A is omitted, that is, the laminated film may be a release film 15.

[0094] The adhesive layer 12A used in the second embodiment is as described above, and the adhesive layer 12A is a layer that adheres adherents such as optical components such as OCAs. Therefore, the adhesive layer 12A in the second embodiment is preferably formed of an adhesive with high adhesive strength to the adherents. The adhesive strength can be adjusted by conventionally known methods.

[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 mainly composed of curable silicone resin, and is positioned on the opposite side of the base film described above. The release layer can also be said to be a release layer containing a cured product formed by curing the release layer composition.

[0096] Furthermore, the term "main component resin" in the release layer refers to the resin with the largest mass percentage among the resins constituting the release layer composition, and is expected to account for 50% or more by mass, or 75% or more by mass, or 90% or more by mass, or 100% by mass of the resins constituting this release layer composition.

[0097] The curable silicone resin may be a resin mainly composed of curable silicone resin, or it may be a modified silicone obtained by graft polymerization with organic resins such as acrylic resin, urethane resin, epoxy resin, or alkyd resin. Furthermore, if the adhesive layer used in combination is a silicone adhesive, it is preferable to include a fluorosilicone resin.

[0098] Any existing curing reaction type of curable silicone resin can be used, including thermosetting types such as addition-curing and condensation-curing types, and electron beam curing types such as ultraviolet-curing types. Multiple types of curable silicone resins may also be used in combination. Furthermore, there are no particular restrictions on the coating form of the curable silicone resin when forming the release layer; it may be in the form of a solution in an organic solvent, a solvent-free form, or an aqueous emulsion form.

[0099] The solventless curable silicone resin is a silicone resin that can be applied without being diluted with a solvent. It consists of short polysiloxane chains and is a silicone resin with a relatively low molecular weight. On the other hand, the solvent-based curable silicone resin is a silicone resin with such a high viscosity that it cannot be applied without being diluted with a solvent, and it is a silicone resin with a relatively high molecular weight compared to the solventless curable silicone resin. From the viewpoints of good adhesion to the base film or resin layer B, a uniform coating appearance without coating unevenness, and easy adjustment of the thickness of the release layer, a solvent-based curable silicone resin is preferred.

[0100] The curable silicone resin used in the present invention preferably consists of a main agent and a silicone crosslinking agent for crosslinking the main agent. There is no limitation on the type of the curable silicone resin, but from the viewpoint of release characteristics excellent in light releasability characteristics and the like, it is preferable to use a curable silicone resin containing an alkenyl group as the main agent. Examples of the curable silicone resin containing an alkenyl group as a diorganopolysiloxane include those represented by the following general formula (4). R (３－ａ) X ａ SiO-(RXSiO) ｍ -(R ２ SiO) 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 from 0 to 3, preferably 1, and m is 0 or greater, but when a = 0, m is 2 or greater, and m and n are numbers that satisfy 100 ≤ m + n ≤ 20000, and the above formula does not mean a block copolymer, and the constituent units in the parentheses of m and n may be bonded randomly. The same applies to formula (5) described later. Specifically, R can be an alkyl group such as a methyl group, ethyl group, propyl group, or butyl group, a cycloalkyl group such as a cyclohexyl group, or an aryl group such as a phenyl group or tolyl group, but methyl and phenyl groups are particularly preferred. X is an organic group containing an alkenyl group, preferably having 2 to 10 carbon atoms. Specifically, examples include vinyl group, allyl group, hexenyl group, octenyl group, acryloylpropyl group, acryloylmethyl group, methacryloylpropyl group, cyclohexenylethyl group, vinyloxypropyl group, etc., but vinyl group, hexenyl group, etc. are particularly preferred. Specific examples of curable silicone resins include dimethylsiloxane / methylhexenylsiloxane copolymers with trimethylsiloxy groups sealed at both ends of the molecular chain (e.g., 96 mol% dimethylsiloxane units, 4 mol% methylhexenylsiloxane units), dimethylsiloxane / methylhexenylsiloxane copolymers with dimethylvinylsiloxy groups sealed at both ends of the molecular chain (e.g., 97 mol% dimethylsiloxane units, 3 mol% methylhexenylsiloxane units), and dimethylsiloxane / methylhexenylsiloxane copolymers with dimethylhexenylsiloxy groups sealed at both ends of the molecular chain (e.g., 95 mol% dimethylsiloxane units, 5 mol% methylhexenylsiloxane units).

[0102] When using a curable silicone resin containing alkenyl groups, it is preferable that the curable silicone resin further contains a polyorganosiloxane containing SiH groups. The polyorganosiloxane containing SiH groups may act as a silicone crosslinking agent for crosslinking the alkenyl-containing curable silicone resin. The polyorganosiloxane containing SiH groups reacts with the alkenyl-containing curable silicone resin 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 in one molecule. Linear, branched, or cyclic polyorganosiloxanes can be used, and compounds represented by the following general formula (5) can be cited, but are not limited to these. ｂ R １ (３－ｂ) SiO-(HR １ SiO) ｘ - (R １ ２ SiO) ｙ -SiR １ (３－ｂ) H ｂ ... (5)

[0103] In general formula (5), R １ b is a monovalent hydrocarbon group having 1 to 6 carbon atoms and not containing an aliphatic unsaturated bond. b is an integer from 0 to 3, and x and y are integers. Specifically, examples include methylhydrogenpolysiloxane with trimethylsiloxy groups sealed at both ends of the molecular chain, dimethylsiloxane / methylhydrogensiloxane copolymer with trimethylsiloxy groups sealed at both ends of the molecular chain, methylhydrogenpolysiloxane with dimethylhydrogensiloxy groups sealed at both ends of the molecular chain, and dimethylsiloxane / methylhydrogensiloxane copolymer with dimethylhydrogensiloxy groups sealed at both ends of the molecular chain.

[0104] Next, to give specific examples of various commercially available types of silicone resins that can be used in the present invention, Shin-Etsu Chemical Co., Ltd. has produced 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, X-41-3035, 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, and manufactured by Toray Dow Corning Co., Ltd.: SRX357, SRX211, SD7220, S Examples include 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, etc. from the DEHESIVE series manufactured by Asahi Kasei Wacker Silicone Co., Ltd., but are not limited to these.

[0105] For the release layer, it is preferable to use a platinum-based catalyst as a curing catalyst to promote the addition reaction. Examples of this component include platinum-based compounds such as chloroplatinic acid, an alcoholic solution of chloroplatinic acid, a complex of chloroplatinic acid with an olefin, a complex of chloroplatinic acid with an alkenylsiloxane, platinum black, platinum-supported silica, and platinum-supported activated carbon.

[0106] The content of the curing catalyst in the release layer is preferably 0.5 to 500 ppm by mass in terms of metal equivalent relative to the curable silicone resin, more preferably 5 ppm by mass or more, even more preferably 10 ppm by mass or more, more preferably 300 ppm by mass or less, and even more preferably 200 ppm by mass or less. If the platinum-based catalyst content in the release layer is above the lower limit, sufficient release force is obtained, the curing reaction proceeds sufficiently, and no problems such as deterioration of the coating surface occur. On the other hand, if the platinum-based catalyst content in the release layer is below the upper limit, it is cost-effective, and process problems such as increased reactivity and generation of gel foreign matter do not occur.

[0107] Furthermore, because addition reactions are highly 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, and is preferably a compound selected from the group consisting of 3-methyl-1-butyne-3-ol, 3,5-dimethyl-1-hexyne-3-ol, and phenylbutynol.

[0108] The content of the reaction control agent 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 curable silicone resin is not inhibited from curing without reducing the reaction activity, and the easy peelability 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 promoting 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 dimethyloxide, dibutylbis(triethoxysiloxy)tin, and dibutyltin benzylmalate; KF, NH ４ Examples include fluorine-containing compounds such as F. The catalysts may be used alone or in combination of two or more types. Among these, organometallic salts are particularly preferred because they provide good coating film durability.

[0110] Various release control agents may be used in combination to adjust the release properties of the release layer. When increasing the release force, organopolysiloxane resin, silica particles, or silicone with high release force may be included in the release layer in appropriate amounts as a high release agent to obtain the desired release force. Among these, organopolysiloxane resin and silicone resins such as silicone are preferred.

[0111] Examples of commercially available heavy-duty stripping agents include X-92-183 and KS-3800 from Shin-Etsu Chemical Co., Ltd., and SD7292, BY24-843, and BY24-4980 from Toray Dow Corning Co., Ltd.

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

[0113] To reduce the release force, it is advisable to appropriately select a low molecular weight siloxane compound or similar as a light release agent and incorporate it into the release layer in an appropriate amount so that the siloxane migration component exhibits release properties. Examples of low molecular weight siloxane compounds include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and other low molecular weight cyclic siloxanes. In addition to these low molecular weight cyclic siloxanes, other compounds include dimethylsiloxane oligomers with trimethylsiloxy groups sealed at both ends of the molecular chain and dimethylsiloxane oligomers with dimethylhydroxysiloxy groups sealed at both ends of the molecular chain, and these compounds may be mixed and used as needed.

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

[0115]

[0116]

[0117] The content of light release agents such as low molecular weight siloxane compounds 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, based on 100% by mass of the silicone resin in the release layer. If the content is 0.1% by mass or more, the migratory components are sufficient, allowing the release properties to be fully exhibited and the desired light release properties to be achieved. Furthermore, if the content is 15.0% by mass or less, the migratory components do not precipitate excessively, eliminating concerns about process contamination.

[0118] The release layer composition may contain a diluent as needed. Examples of diluent 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 individually or in combination, taking into consideration their solubility, coating properties, boiling point, etc.

[0119] Furthermore, it is preferable to use an organosilicon compound represented by the following general formula (8) in the release layer to improve the adhesion of the coating to the film. Si(X) ｄ (Y) ｅ (R １ ) ｆ ... (8) [In the above formula, X is an organic group having at least one selected from epoxy group, mercapto group, (meth)acryloyl group, alkenyl group, haloalkyl group and amino group, R １ [where 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) may have two hydrolyzable groups Y that can form siloxane bonds through hydrolysis and condensation reactions (D unit source) or three hydrolyzable groups Y that can form siloxane bonds (T unit source).

[0121] In general formula (8), the monovalent hydrocarbon group R１ The carbon group can have 1 to 10 carbon atoms, but alkyl groups, particularly methyl, ethyl, and propyl groups, are preferred.

[0122] In general formula (8), the hydrolyzable group Y can be exemplified by the following: namely, methoxy group, ethoxy group, butoxy group, isopropenoxy group, acetoxy group, butanoxyme group, and amino group. These hydrolyzable groups may be used individually or in combination. Among these, the methoxy group or ethoxy group is particularly preferred because it can impart good storage stability to the release layer composition as a coating agent and also has 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 is substantially free of particles. By substantially free of particles in the release layer, the release properties can be stabilized while reducing migration. Substantially free means that the release layer may contain particles in small amounts that do not hinder the effects of the present invention, and may contain particles that are inevitably mixed in, for example. Specifically, the 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. The range of particle content in the release layer composition based on non-volatile components is the same as the particle content described above.

[0125] Furthermore, to the extent that it does not impair the spirit of the present invention, the release layer, i.e., the release layer composition, may optionally contain defoaming agents, coating properties improvers, thickeners, organic lubricants, antistatic agents, conductive agents, ultraviolet absorbers, antioxidants, foaming agents, dyes, pigments, 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 laminated 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. If the number-average molecular weight (Mn) of the curable silicone resin is above the lower limit, the amount of low molecular weight silicone resin that dissolves or migrates to the adhesive layer when the adhesive layer is laminated on the release layer can be reduced, and a light release effect can be easily obtained by applying a thicker release layer. On the other hand, if the number-average molecular weight (Mn) of the curable silicone resin is below the upper limit, the viscosity will not increase and the fluidity of the release layer composition will not decrease. Therefore, when the release layer composition is applied, streaky coating unevenness will not occur, and the surface of the release layer will be easier to smooth. From this viewpoint, the number-average molecular weight (Mn) of the curable silicone resin is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, and especially most preferably 10,000 or more. On the other hand, it is preferable that it be 1,000,000 or less, more preferably 200,000 or less, and even more preferably 100,000 or less.

[0127] 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, particularly preferably 15,000 or more, even more preferably 250,000 or less, and even more preferably 100,000 or less.

[0128] The ratio of mass-average molecular weight (Mw) to number-average molecular weight (Mn) (Mw / 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. Satisfying this range is expected to allow the crosslinking reaction to proceed efficiently.

[0129] The curable silicone resin may consist of a combination of two or more curable silicone resins, in which case it is preferable that the average of the number-average molecular weight (Mn) and mass-average molecular weight (Mw) of the two or more curable silicone resins is within the above range. The average referred to here is a weighted average weighted by the mass of each resin. Furthermore, when a main component and a silicone crosslinking agent are used as the curable silicone resin, it is preferable that the number-average molecular weight (Mn), mass-average molecular weight (Mw), and Mw / Mn of the main component are within the above range. In addition, it is preferable that the number-average molecular weight and mass-average molecular weight of the silicone resin, light release agent, and heavy release agent be measured by gel permeation chromatography (GPC).

[0130] The curable silicone resin, when adjusted to 15% by mass by dilution with n-heptane solvent, has a viscosity at 25°C of preferably 1 to 400 mcps, more preferably 5 to 300 mcps, and even more preferably 10 to 200 mcps. A viscosity of 1 mcps or higher is preferable because the appropriate viscosity of the coating liquid suppresses repelling and a highly visible, uniform coating appearance can be obtained. A viscosity of 400 mcps or lower maintains the fluidity of the release layer composition, suppresses the occurrence of streaky coating unevenness when the release layer composition is applied, and allows for a smooth release layer surface. When using a main component and a silicone crosslinking agent as the curable silicone resin, it is preferable that the viscosity of the main component be within the above range.

[0131] When a curable silicone resin contains alkenyl groups, the content of 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 are contained, so the release layer hardens sufficiently, while preventing an increase in peeling force after exposure to air by avoiding an excess of alkenyl groups.

[0132] When a curable silicone resin contains Si-H groups, the Si-H group content 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 siloxane component amount. By satisfying this range, a certain amount or more of Si-H groups are contained, allowing the release layer to harden sufficiently. At the same time, the amount of Si-H groups is not excessive, preventing reaction with the adhesive layer and suppressing excessive peeling of the release layer.

[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, which consists of siloxane bonds, within the same structure. In this case as well, it is preferable that the content of alkenyl groups and Si-H groups in the curable silicone resin is within the above range.

[0134] The thickness of the release layer, expressed as mass per unit area, is preferably 0.1 to 2.0 g / m². ２ The release layer thickness is 0.1 g / m². ２ This makes it easier to lightly peel off the release layer. Also, 2.0 g / m ２ By doing the following, it is possible to prevent an increase in the migration of the release layer components to the adhesive layer, etc., and also to effectively prevent blocking. From the above viewpoint, the thickness of the release layer is more preferably 0.1 to 1.5 g / m². ２ More preferably 0.1 to 1.0 g / m ２ This is within the specified range. Note that the release layer may be formed by applying a release layer composition and drying it, as described later; however, the thickness of the release layer mentioned above is the thickness after drying.

[0135] The release layer may be formed by in-line coating, which treats the film surface during the film-making process of the base film, or by off-line coating, which is applied to the base film after it has been manufactured, but it is more preferably formed by off-line coating. The release layer is formed by applying the release layer composition to the surface of the base film and curing, drying, etc., as necessary. The release layer is formed on a base film on which resin layer A, or resin layer A and resin layer B have been formed.

[0136] Conventional coating methods such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, and curtain coating can be used as methods for applying the release layer composition to the base film.

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

[0138] Furthermore, heat treatment and active energy ray irradiation, such as ultraviolet irradiation, may be used in combination as needed. Known devices and energy sources can be used as the energy source for curing by active energy ray irradiation. For example, fusion (H) lamps, metal halide lamps, high-pressure mercury lamps (ozone-generating type, ozone-free type), and UV-LEDs can be used as light sources.

[0139] While there are no particular limitations on the type of active energy irradiation, in the case of ultraviolet irradiation, the cumulative light intensity should be 10 to 3000 mJ / cm². ２ Preferably 50 to 2000 mJ / cm² ２ More preferably 100 to 1000 mJ / cm ２This range is ideal. By keeping the cumulative light intensity of UV irradiation within the above range, the hardening of the release layer is promoted, while excessive irradiation is prevented from damaging the release layer and reducing the peeling force after irradiation.

[0140] (Dielectric constant of the surface of resin layer A) The dielectric constant of the surface of resin layer A in the laminated film of the present invention is 5.5 or less. If the dielectric constant of the surface of resin layer A is greater than 5.5, the low dielectric constant characteristics become insufficient. As a result, adequate conductive characteristics cannot be secured, and if it is used, for example, for protecting an integrated image display device (e.g., a smartphone) that combines an OLED and a touch sensor, or for protecting the adhesive layer that joins components mounted on this image display device, there is a risk of malfunction of the touch panel. Furthermore, the laminated film of the present invention may be used, for example, as a process film when manufacturing an integrated image display device, and in that case, an operation confirmation test may be performed with the laminated film of the present invention attached to the adherend, but if the dielectric constant is greater than 5.5, problems such as the inability to properly perform the operation confirmation test due to malfunction will occur. The dielectric constant of the surface of resin layer A in the laminated film is preferably 5.0 or less, more preferably 4.5 or less, and even more preferably 3.8 or less. On the other hand, as for the lower limit of the dielectric constant of the surface of resin layer A in the laminated film, it is preferable to be 3.0 or more. By maintaining a dielectric constant above a certain level, the laminated film can be given appropriate conductive properties, improving its antistatic properties and preventing peeling charge and adhesion of foreign matter. The dielectric constant is the dielectric constant at a frequency of 1000 Hz, and the details of its measurement method are shown in the examples.

[0141] Furthermore, the inventors discovered that there is a roughly inverse correlation between the dielectric constant and the surface resistivity, and thus completed the present invention. That is, as the dielectric constant decreases, the surface resistivity increases. Therefore, as described above, by setting the dielectric constant below a certain level to impart low dielectric constant characteristics, it is possible to prevent malfunctions of touch panels in integrated image display devices, for example. Also, 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 inventors then discovered that the dielectric constant can be adjusted using a thin resin layer of several nanometers to several hundred nanometers, preferably at the level of several tens of nanometers, as described above, and 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 a laminated 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 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 if resin layer B is provided, and the surface resistivity of the substrate film surface without resin layer B if 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. For a laminated film, if the surface resistivity of either the surface of resin layer A or the opposite surface of resin layer A is, for example, 1 × 10⁻⁶ ６ Ω or more, 5×10 ８ The following is true: 5 × 10 ６ Ω / □ or more, 1×10 ８A value of Ω / □ or less is preferable. By satisfying the above range, while maintaining good antistatic properties, malfunctions become less likely to occur, for example, when used to protect the display screen of a touch panel in an integrated image display device. In this invention, the above problem is solved by using a method that is not normally adopted, which involves deliberately lowering the surface resistivity of a laminated film used in applications where antistatic performance is required. The surface resistivity of the other surface of resin layer A or the opposite surface of resin layer A may be within the above range or outside the above range. The surface resistivity of the other surface may be, for example, 1 × 10⁻⁶ from the viewpoint of antistatic properties. ４ Ω or more, 5×10 ８ The following, preferably 1 × 10 ５ Ω / □ or more, 1×10 ８ A value of Ω / □ or less is preferred. The surface resistivity of the surface of resin layer A or the surface opposite to resin layer A can be measured as shown in the following example.

[0143] <Adhesive Sheet> The laminated film of the present invention can be used as an adhesive sheet if it has an adhesive layer. For example, in each of the above embodiments, the laminated film having an adhesive layer may be made into an adhesive sheet by further laminating a release film (hereinafter, for convenience, sometimes referred to as the "second release film") onto the surface of the adhesive layer. The second release film may be a conventionally known release film, which may be release paper with a release treatment applied to at least one side of a paper substrate, or a release resin film with a release treatment applied to at least one side of a resin film. However, the release treatment may be omitted as long as it can be easily peeled off from the adhesive layer. Alternatively, the first release film described above may be used as the second release film.

[0144] In the present invention, any of the laminated films 10 and 10A according to the first and second embodiments illustrated in Figures 1 and 2 above may be made into an adhesive sheet by laminating a second release film (not shown) to the surface of the adhesive layer 12. For example, if the laminated film 10A according to the second embodiment is laminated with the second release film to form an adhesive sheet, it becomes a double-sided adhesive sheet in which the first release film and the second release film are laminated to both sides of the adhesive layer 12A. Alternatively, if the laminated film 10 according to the first embodiment is laminated with the second release film to form an adhesive sheet, it becomes a single-sided adhesive sheet in which the adhesive layer 12 and the second release film are laminated in that order to one side (opposite side) of the base film. The adhesive sheet is preferably used by laminating the surface of the exposed adhesive layer to the surface of an object to be adhered, such as an optical member, after peeling off the second release film.

[0145] <<Applications and Methods of Use>> The laminated film and adhesive sheet of the present invention are suitable for use in optical component applications. For example, if the laminated film has an adhesive layer, it is suitable for use by laminating the adhesive layer to an optical component. The laminated film, which has been laminated to an optical component via the adhesive layer, is suitable for use to protect the optical component. The laminated film is then suitable for being peeled off from the optical component once its purpose has been achieved.

[0146] As shown in the second embodiment described above, if the laminated film has a release layer, it may be used to protect the adhesive layer, for example, to protect the adhesive layer laminated on the release layer. The laminated film can also be used to join components that make up an optical member. For example, if the laminated film has a release layer, the adhesive layer laminated on the release layer may be used to join components that make up an optical member. In this case, the adhesive layer may be used to join components after it has been peeled off from the first release film. Furthermore, an OCA adhesive sheet configuration is also possible, in which the adhesive layer is sandwiched between release films on both sides, as in the adhesive sheet described above. In this case, the adhesive layer may be used to join components after it has been peeled off from the release films on both sides (the first and second release films).

[0147] The optical components described above are preferably image display devices. Therefore, if the laminated film has an adhesive layer, it is preferable to use it to protect the image display device by laminating it to the image display device. Among these, 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, it is more preferable for the laminated film to be used to protect an integrated image display device of an OLED and a touch sensor. The image display device in which the laminated film is used may be a finished product or a manufacturing intermediate. However, even if it is a manufacturing intermediate, it is preferable that the image display element such as an OLED and the touch sensor are already incorporated. In this specification, the term "image display device" also includes manufacturing intermediates of image display devices. Furthermore, the term "integrated image display device" also includes manufacturing intermediates if the image display element such as an OLED and the touch sensor are already integrated. Therefore, it may be used as a process film to be laminated to a manufacturing intermediate when manufacturing optical components such as the integrated image display device of the present invention.

[0148] More specifically, it can be used in the manufacturing or transportation processes of displays such as touch panels to protect the display screen from scratches or to prevent malfunctions when touching the display screen. In particular, it is suitable for protecting the display screen of an integrated image display device (for example, a smartphone) that combines an OLED and a touch sensor. Furthermore, if the laminated film is a release film with an adhesive layer, the adhesive layer can also be suitably used for joining components that constitute the image display device. In that case, the first release film can also be used in the image display device to protect the adhesive layer that adheres components together. Here, the components that are joined by the adhesive layer are preferably components that constitute the integrated image display device described above. Furthermore, the adhesive sheet described above may also be used for optical components, but is preferably used for image display devices, more preferably for integrated image display devices, and, similar to the laminated film described above, may be used, for example, for lamination to an integrated image display device or for joining components that constitute an integrated image display device.

[0149] The laminated film has excellent low dielectric constant properties. Therefore, the laminated film can prevent malfunctions even in optical components that are prone to malfunctions, such as integrated image display devices. As a result, even if the laminated film is attached to an integrated image display device and other equipment, the operation can be properly checked. Furthermore, since the laminated film has a certain degree of antistatic properties, it can prevent peeling charge, adhesion of foreign matter, and entrapment of foreign matter, making it suitable for use with optical components.

[0150] In an integrated image display device, the touch panel is preferably positioned on the surface side of the image display element, and the laminated film of the present invention is preferably bonded to the surface side of the touch panel. The laminated film may be directly bonded 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 preferable to bond it to the surface layer if one is present.

[0151] An integrated image display device, using OLED as an example, has a touch sensor provided in an on-cell structure on an organic EL element that constitutes the image display element. For example, the touch sensor is directly laminated on the encapsulation layer of the organic EL element. The encapsulation layer is a layer made of a sealing material that encapsulates the organic EL element and is laminated on the organic EL element. The encapsulation layer may be a single layer or a multilayer of two or more layers.

[0152] As touch sensors, known methods such as electromagnetic induction, capacitive, and pressure-sensitive types can be used, but capacitive types are preferred. Touch sensors can also include, but are not limited to, touch panels made of glass film, PET film, or other resin films. Furthermore, in integrated image display devices, 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, although the surface layer is not required. A known polarizing film may be used as the polarizing element. A known resin film may be used as the protective film.

[0153] Furthermore, in an integrated image display device, a cover member may be provided on the surface side of the touch sensor. Examples of cover members include plastic covers and glass covers, but a glass cover is 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 back 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 substrates include glass substrates and plastic substrates, but plastic substrates are preferred.

[0155] A specific example of an integrated image display device is shown in Figure 3. As shown in Figure 3, the integrated image display device 20 may be configured such that a plastic substrate 21, an organic EL element (OLED) 22, an encapsulation layer 23, a touch sensor 24, a polarizing element 25, an adhesive layer 26, and a cover glass 27 are provided in this order, but the integrated image display device 20 is not limited to this configuration. The adhesive layer 26 may be the adhesive layer 12A of a laminated film (for example, a release film with an adhesive layer in the second embodiment) as described above, but is not particularly limited.

[0156] Next, the method of using the laminated film of the present invention will be described in more detail with reference to the method of manufacturing the integrated image display device shown in Figure 3 above. The following method of use will be described using the case in which both the laminated film of the first embodiment and the laminated film of the second embodiment (release film with adhesive layer) are used as examples. However, it is not necessary to use both the laminated films of the first and second embodiments; only one may be used, or a known laminated film may be used instead of the laminated film of the first or second embodiment.

[0157] When manufacturing the image display device shown in Figure 3 above, for example, steps 1 to 4 below may be performed in this order. Step 1: A step of bonding the surface of the adhesive layer 12 of the laminated film 10 onto the polarizing element 25 and transporting it (see Figure 4). Step 2: After peeling off the laminated film 10, a step of bonding the surface of the adhesive layer 12A of the release film 10A with the adhesive layer to the polarizing element 25 (see Figure 5). Step 3: A step of peeling off the release film 15 while leaving the adhesive layer 12A in place (see Figure 6). Step 4: A step of bonding the cover glass 27 to the surface of the adhesive layer 12A (see Figure 3).

[0158] In step 1, as shown in Figure 4, an image display device member 30, which is a manufacturing intermediate for the image display device, is prepared, and a laminated film 10 is bonded to the 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 other than the adhesive layer and cover glass of the image display device 20 shown in Figure 3 are laminated. The laminated film 10 used in step 1 is, for example, the laminated film 10 according to the first embodiment shown in Figure 1, and is used as a protective film. The image display device member 30 is then protected by the laminated film 10, for example, during transport.

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

[0160] In the above manufacturing method, it is preferable to perform a functional check of the touch sensor. The functional check of the touch sensor can be performed in either step 1 or step 2. Specifically, it is preferable to perform the functional check of the touch sensor when the laminated film 10 or the release film 10A with an adhesive layer is attached to the image display device member 30. With this functional check, there is no need to perform a separate functional check of the touch sensor, and it is possible to utilize the state in which the laminated film 10 or the release film 10A with an adhesive layer is attached, resulting in good production efficiency. The manufacturer can arbitrarily choose which step to perform the functional check in.

[0161] <<<Explanation of Terms>>> In this invention, the term "film" includes "sheets," and the term "sheet" includes "film." In this invention, when "X to Y" (where X and Y are arbitrary numbers) is written, unless otherwise specified, it includes the meaning of "greater than or equal to X and less than or equal to Y," as well as "preferably greater than X" or "preferably less than Y." Also, when "greater than or equal to X" (where X is any number) is written, unless otherwise specified, it includes the meaning of "preferably greater than X," and when "less than or equal to Y" (where Y is any number) is written, unless otherwise specified, it also includes the meaning of "preferably less than Y."

[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 without exceeding its gist. 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 incompatible components have been removed was accurately 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 (Hitachi H-7650, acceleration voltage 100V), and the average particle size was defined as the average value of the particle sizes of 10 particles.

[0165] (3) Thickness of the resin layer The surface of the resin layer is made of RuO ４ The tissue was stained and embedded in epoxy resin. Subsequently, sections prepared by the ultrathin sectioning method were placed in RuO ４ The resin layer was stained, and its cross-section was measured using a transmission electron microscope (TEM) (Hitachi High-Technologies Corporation, H-7650, accelerating voltage 100kV).

[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 Circuit Design Block Co., Ltd. For each sample, n=2 measurements were taken in ultra-low speed, high-precision mode, and the dielectric constant at 1000 Hz was determined.

[0167] (5) Surface resistivity of laminated film Using a low resistivity meter (Loresta GPMCP-T600 manufactured by Nitto Seiko Analytech Co., Ltd.), a four-probe ESP probe was used to conditioned each film sample obtained in the examples and comparative examples for 30 minutes in a measurement atmosphere of 23°C and 50% RH. The surface resistance of the surface of resin layer A was then measured to determine the surface resistivity. Note that the measurement limit of the low resistivity meter was (1 × 10⁻⁶). ８ If the value exceeds Ω / □, it is indicated as "OVER". 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 surface 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)> Using 100 parts by mass of dimethyl terephthalate and 55 parts by mass of ethylene glycol as starting materials, 0.04 parts by mass of magnesium acetate tetrahydrate was added to the reactor as a catalyst, and the reaction start temperature was set to 150°C. The reaction temperature was gradually increased with the distillation of methanol, and after 3 hours it was set to 230°C. After 4 hours the transesterification reaction was substantially completed. After adding 0.02 parts by mass of ethyl acid phosphate to this reaction mixture, 0.04 parts by mass of antimony trioxide was added, and a 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 until it was finally 0.3 mmHg. After the start of the reaction, the reaction was stopped at a point corresponding to an intrinsic viscosity of 0.65 dL / g by changing the stirring power of the reaction vessel, and the polymer was discharged under nitrogen pressure to obtain polyester (1) with an intrinsic viscosity of 0.65 dL / g.

[0170] <Method for producing polyester (2)> Using 100 parts by mass of dimethyl terephthalate and 45 parts by mass of ethylene glycol as starting materials, 0.06 parts by mass of magnesium acetate tetrahydrate was added to the reactor as a catalyst, and the reaction start temperature was set to 150°C. The reaction temperature was gradually increased with the distillation of methanol, and after 3 hours it was set to 230°C. After 4 hours the transesterification reaction was substantially completed. After adding 0.03 parts by mass of ethyl acid phosphate to this reaction mixture, 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 were added, and a polycondensation reaction was carried out for 4 hours. The temperature was gradually increased from 230°C to 280°C. Meanwhile, the pressure was gradually decreased from atmospheric pressure, and finally it was set to 0.3 mmHg. After the reaction started, the reaction was stopped by changing the stirring power of the reaction vessel at a point corresponding to an intrinsic viscosity of 0.65 dL / g, and the polymer was discharged under nitrogen pressure to obtain 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 compounds (A1): A conductive agent consisting of polyethylenedioxythiophene and polystyrene sulfonic acid (Orgacon ICP1010, manufactured by Agfa-Gevaert), neutralized with concentrated ammonia water to a pH of 9. (A2): Polyaniline sulfonic acid (aqua-PA SS, manufactured by Mitsubishi Chemical Corporation, main repeating unit: methoxy group substituted aminobenzene sulfonic acid)

[0173] Binder resin (B1): A dispersion of polyester polyurethane polymerized with the following composition, where (C1a) is a polyester polyol comprising 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. The dispersion is obtained by neutralizing ammonia and dispersing the polyester polyurethane, which is composed of 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, in aqueous solution (non-volatile content concentration 20%, viscosity 50 mPa·s at 25°C). (B2): A dispersion of urethane acrylate resin polymerized with the following composition, consisting of hydrogenated xylylene diisocyanate, (di)pentaerythritol-based acrylate, poly(1,6-hexylene) carbonate, and dimethylolpropanoic acid.

[0174] Polyglycerin and / or alkylene oxide adducts to polyglycerin (C1): Compounds in which an average of 4 molecules of polyethylene oxide are added to a polyglycerin skeleton with an average n=2 in formula (3) above. (C2): Polyglycerin with an average n=2 in formula (3) above.

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

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

[0177] Example 1 A blend of polyester (1) and polyester (2) in a mass ratio of 82 / 18 was used as the raw material for layer A, and polyester (1) alone was used as the raw material for layer B. Both were supplied to an extruder, heated and melted at 285°C, and layer A was divided into two to form the outermost layer (surface layer), and layer B was used as the intermediate layer, resulting in a two-layer, three-layer structure (A / B / A). The extrusion conditions were set so that the thickness composition ratio A / B / A = 5 / 90 / 5, and the film was co-extruded. The film was cooled and solidified while in close contact with a mirror-cooled drum with 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% by mass. 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 (coating solutions 1 and 2) shown in Table 1 below were applied to both sides of the uniaxially oriented film. The film was then guided into a tenter stretcher and stretched 4.3 times in the width direction at 100°C. After further heat treatment at 230°C, a 2% relaxation treatment was performed in the width direction to obtain a biaxially oriented polyester film with a thickness of 50 μm, having a resin layer A with a film thickness (after drying) of 80 nm and a resin layer B with a film thickness (after drying) of 30 nm.

[0178] Next, an adhesive layer consisting of the following adhesive composition was applied to resin layer B to a thickness (wet state) of 2 mil (= approximately 51 μm) and dried to obtain a laminated film. (Adhesive composition) Main component: 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) 100 parts by mass Curing agent: Takenate D-101E (manufactured by Mitsui Chemicals, Inc.) 50 parts by mass Ethyl acetate: 50 parts by mass In the obtained laminated film, the dielectric constant at 1000 Hz on the surface of resin layer A was 3.5. The properties of this film are shown in Table 2 below.

[0179] Examples 2-3 were carried out in the same manner as in Example 1, except that the resin composition was changed to the composition shown in Table 1, to obtain laminated films. The results are shown in Table 2.

[0180] Example 4 A blend of polyester (1) and polyester (2) in a mass ratio of 82 / 18 was used as the raw material for layer A, and polyester (1) alone was used as the raw material for layer B. Both were supplied to an extruder and heated and melted at 285°C. Layer A was divided into two to form the outermost layer (surface layer), and layer B was used as the intermediate layer, resulting in a two-layer, three-layer structure (A / B / A). The extrusion conditions were set so that the thickness composition ratio A / B / A = 5 / 90 / 5, and the film was co-extruded. The film was cooled and solidified while in close contact with a mirror-cooled drum with 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 the uniaxially oriented film. The film was then guided into a tenter stretcher and stretched 4.3 times in the width direction at 100°C. After further heat treatment at 230°C, a 2% relaxation treatment was performed in the width direction to obtain a biaxially oriented polyester film with a thickness of 50 μm, having a resin layer A with a film thickness (after drying) of 80 nm and a resin layer B with a film thickness (after drying) of 30 nm.

[0181] Next, a release layer consisting of the release layer composition described below is applied to the resin layer B, with a thickness (after drying) of 0.1 g / m². ２ The material was applied to obtain a release film. (Release layer composition) Curable silicone resin (Shin-Etsu Chemical Co., Ltd. X-62-5039): 80 parts by mass Curable silicone resin (Shin-Etsu Chemical Co., Ltd. KS-3800): 20 parts by mass Curing agent (curing catalyst) (Shin-Etsu Chemical Co., Ltd. PL-5000): 2 parts by mass Solvent: Toluene 600 parts by mass, MEK 600 parts by mass, and hexane 600 parts by mass In the obtained release film, the dielectric constant of the surface of resin layer A at 1000 Hz was 3.5. The properties of this film are shown in Table 2 below.

[0182] Examples 5-6 and Comparative Examples 1-3 were carried out in the same manner as in Example 1, except that the resin composition was changed to the composition shown in Table 1, to obtain release films. The results are shown in Table 2.

[0183] The values ​​in Table 1 represent parts by mass based on non-volatile components.

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

[0185] As shown in Table 2, the dielectric constant of the resin layer A surface of the laminated film in each embodiment satisfies the requirement of 5.5 or less. Therefore, when used for protecting the display screen of an OLED and touch sensor integrated image display device (e.g., a smartphone) or for protecting the adhesive layer that joins components mounted on the image display device, it can be expected that the risk of malfunction and the risk of foreign matter adhesion will be low. On the other hand, in each comparative example, the dielectric constant was outside the desired range, so it can be seen that when used for protecting the display screen of an OLED and touch sensor integrated image display device (e.g., a smartphone) or for protecting the adhesive layer that joins components mounted on the image display device, the risk of malfunction will be high. Furthermore, a feature of the present invention is that we found that the dielectric constant has a good correlation with the surface resistivity, and that if the surface resistivity is too good, i.e., too small, the risk of malfunction will conversely increase. Therefore, in this invention, we deliberately designed the device to have reduced performance, and by using a thin resin layer, we were able to adjust the dielectric constant to the desired range, thus completing the invention through a technological approach that goes against conventional methods.

[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 EL element (OLED) 23 Encapsulation layer 24 Touch sensor 25 Polarizing element 27 Cover glass 30 Image display device component A Resin layer A B Resin layer B

Claims

1. A laminated film 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 an adhesive layer and a release layer on the opposite surface of the base film, wherein the binder resin content 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 claim 1, wherein the base film is a polyester film.

3. The laminated film according to claim 1, wherein the conductive polymer compound comprises a polymer obtained by doping a compound consisting of thiophene or a thiophene derivative with another anionic compound.

4. The laminated film according to claim 3, wherein the resin layer A contains one or more compounds selected from polyglycerin and alkylene oxide adducts to polyglycerin, or derivatives thereof.

5. The laminated film according to claim 4, wherein one or more compounds selected from polyglycerin and alkylene oxide adducts to polyglycerin, or derivatives thereof, is polyglycerin represented by the following general formula (3). (n is an integer in the range of 2 to 20.) 6. The laminated film according to claim 1, wherein the content of one or more compounds selected from polyglycerin and alkylene oxide adducts to polyglycerin, or derivatives thereof, in the resin layer A is 0 to 60% by mass.

7. The laminated film according to claim 1, 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 ６ (Ω / □) or more, 5×10 ８ The laminated film according to claim 1, wherein the coefficient is less than or equal to (Ω / □).

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

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

11. The laminated film according to claim 1, wherein the opposite side of the base film is provided with a resin layer B containing a binder resin.

12. The laminated film according to claim 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 claim 11, wherein the resin layer B further comprises a conductive polymer compound.

14. The laminated film according to claim 13, 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 claim 11, wherein the resin layer B contains one or more compounds selected from polyglycerin and alkylene oxide adducts to polyglycerin, or derivatives thereof.

16. The laminated film according to claim 15, wherein one or more compounds selected from polyglycerin and alkylene oxide adducts to polyglycerin, or derivatives thereof, in the resin layer B is polyglycerin represented by the following general formula (3). (n is an integer in the range of 2 to 20.) 17. The laminated film according to claim 11, wherein the content of one or more compounds selected from polyglycerin and alkylene oxide adducts to polyglycerin, or derivatives thereof, in the resin layer B is 0 to 60% by mass.

18. The laminated film according to claim 11, wherein the resin layer B does not contain a crosslinking agent.

19. The laminated film according to claim 11, wherein the resin layer B contains two types of conductive polymer compounds.

20. The laminated film according to claim 19, wherein the two types of conductive polymer compounds in the resin layer B are a polymer obtained by doping a compound consisting of thiophene or a thiophene derivative with another anionic compound, and a polyaniline compound.

21. The laminated film according to claim 1, wherein the adhesive layer is made of an acrylic, urethane, or silicone adhesive.

22. The laminated film according to claim 1, wherein the adhesive layer is made of an adhesive that does not have antistatic properties.

23. The laminated film according to claim 1, wherein the release layer and the adhesive layer are provided in this order on the opposite side of the base film.

24. The laminated film according to claim 11, wherein the release layer and the adhesive layer are provided in this order on the resin layer B, the release film with an adhesive layer.

25. The laminated film according to claim 1, wherein the release layer contains a curable silicone resin.

26. A method for using a laminated film according to any one of claims 1 to 25, wherein the laminated film comprises the adhesive layer, and the surface of the adhesive layer of the laminated film is bonded to the surface of an optical member.

27. The method of using a laminated film according to claim 26, wherein the optical component is an integrated image display device comprising an OLED and a touch sensor.

28. An adhesive sheet comprising a laminated film according to claim 23 or 24, and a second release film to be bonded to the adhesive layer of the laminated film.

29. A method for using the adhesive sheet according to claim 28, wherein after peeling off the second release film, the surface of the exposed adhesive layer is adhered to the surface of the optical member.

30. The method for using an adhesive sheet according to claim 29, wherein the optical member is an integrated image display device comprising an OLED and a touch sensor.

31. A laminated film according to any one of claims 1 to 25, for protecting an integrated image display device comprising an OLED and a touch sensor.

32. The laminated film according to claim 23 or 24, wherein the adhesive layer is an adhesive layer used in an integrated image display device comprising an OLED and a touch sensor, and the release film is for protecting the adhesive layer.

33. The adhesive sheet according to claim 28, for use in attaching an integrated image display device comprising an OLED and a touch sensor.

Images