JP5056208B2 - Conductive film for in-mold molding and method for producing plastic molded article with transparent conductive layer - Google Patents

Description

  The present invention is suitable for in-mold molding, which is used for in-mold molding in which a transparent conductive layer is laminated and integrated on the surface of a molded product body simultaneously with molding of the molded product body when molding a plastic molded product by injection molding. The present invention relates to a conductive film. The present invention also relates to a method for producing a plastic molded article with a transparent conductive layer by in-mold molding using the transfer conductive film.

  As a molded product with a transparent conductive layer, an electroluminescence panel electrode, an electrochromic device electrode, a liquid crystal electrode, a transparent surface heating element, a transparent electrode such as a touch panel, an electric paper, a capacitance switch, and a transparent electromagnetic wave shielding layer are attached. Display (such as CRT).

  Currently, the transparent conductive layer is mainly produced by a sputtering method. The sputtering method is excellent in that a conductive layer having a low surface electric resistance can be formed even if it has a somewhat large area. However, there is a drawback that the apparatus is large and the film forming speed is slow. In addition, when the surface on which the transparent conductive layer is to be formed is not planar, there is a disadvantage that a uniform conductive layer cannot be formed by sputtering.

  In order to solve the disadvantages caused by the sputtering method, Japanese Patent Application Laid-Open No. 2002-347150 and Japanese Patent Application Laid-Open No. 2003-16842 disclose a conductive layer film for transfer for applying a transparent conductive layer to a target object surface by transfer. ing. The transparent conductive layer is composed of a compressed layer of conductive fine particles provided on the support so as to be peelable from the support. The transfer of the transparent conductive layer to the surface of the target object is performed by ultraviolet irradiation through an adhesive layer provided on the transfer conductive film.

  In JP-A-2004-152221, a transfer film formed by forming a transparent electrode film that can be transferred onto a base film is inserted into an injection mold for molding a touch panel substrate, and a material for molding the touch panel substrate is injected and injected. And the manufacturing method of the electrode substrate for touchscreens by the in-mold shaping | molding which transfers the transparent electrode film of the said transfer film to the touchscreen surface simultaneously with shape | molding a touchscreen substrate is disclosed.

JP 2002-347150 A JP 2003-16842 A JP 2004-152221 A

  According to Japanese Patent Application Laid-Open No. 2004-152221, as a method for forming a transparent electrode film on a base film when producing a transfer film, an electron beam method, a sputtering method, a resistance heating vapor deposition method, a chemical reaction method (sol-gel method) ). In these electrode film forming methods, the electrode film is an inorganic material film and does not contain an organic resin component. For this reason, the electrode film is poor in flexibility and cannot follow strain distortion or the like. In particular, when the film is deformed in a high temperature environment during in-mold molding, a crack is generated in the electrode film, which adversely affects the conductivity. Moreover, since the transparent electrode film of the transfer film and the injected molten resin are in direct contact, the adhesion between the electrode film and the touch panel substrate is not good.

  An object of the present invention is to provide a conductive film for transfer that is suitably used for producing a plastic molded article with a transparent conductive layer by in-mold molding. Another object of the present invention is to provide a method for producing a plastic molded article with a transparent conductive layer by in-mold molding, using the conductive film for transfer.

  In particular, an object of the present invention is to provide a conductive film for transfer that is suitably used for producing a plastic molded article with a transparent conductive layer having a low electrical resistance value by in-mold molding. In particular, an object of the present invention is to provide a method for producing a plastic molded article with a transparent conductive layer having a low electrical resistance value by in-mold molding, using the conductive film for transfer.

  The present inventors have studied a conductive film for transfer that is suitably used for producing a plastic molded article with a transparent conductive layer by in-mold molding, and have reached the present invention.

The present invention includes the following inventions.
(1) A support, a transparent conductive layer that can be peeled off from the support on the support, a cured layer of a radiation curable material on the transparent conductive layer, and a heat-fusible layer on the cured product layer Having at least a resin layer,
The cured product layer of the radiation curable material has a thickness of 0.5 to 7.0 μm,
The hot-melt resin layer has a thickness of 0.5 to 5.0 μm,
The transparent conductive layer is an in-mold conductive film including conductive fine particles and a cured product of the radiation curable material impregnated between the conductive fine particles.

  (2) The conductive fine particles include indium oxide, tin-doped indium oxide (ITO), gallium-doped indium oxide, zinc-doped indium oxide, tin oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), and oxidation. As described in (1) above, selected from the group consisting of zinc, aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), fluorine-doped zinc oxide, indium-doped zinc oxide, boron-doped zinc oxide, and cadmium oxide. Conductive film.

  (3) The conductive film according to (1) or (2), wherein the transparent conductive layer has a thickness of 0.05 to 5 μm.

(4) The conductive film according to any one of (1) to (3), wherein the heat-meltable resin has a melt viscosity of 100 to 10,000 dPa · s / 200 ° C.

(5) The conductive film according to any one of (1) to (4), wherein the heat-meltable resin is a heat-meltable urethane-modified copolymer polyester resin .

(6) The conductive film for in-mold molding is
A dispersion of conductive fine particles is applied onto a support, dried, and a layer containing conductive fine particles is formed.
Compressing the conductive fine particle-containing layer to form a conductive fine particle compressed layer in which voids exist between the conductive fine particles;
On the compressed layer of the conductive fine particles, a radiation curable material is applied and dried to impregnate the radiation curable material between the conductive fine particles, and a layer of the radiation curable material is formed.
Radiation irradiation is performed to cure the radiation curable material impregnated between the conductive fine particles and the radiation curable material forming the layer,
On the cured layer of the obtained radiation-curable material, a hot-melt resin is applied and dried to form a hot-melt resin layer.
The conductive film according to any one of (1) to (5), which is obtained by the above.

(7) A method for producing a plastic molded article with a transparent conductive layer comprising a plastic molded article main body and a transparent conductive layer applied to the surface of the molded article main body by in-mold molding,
A support, a transparent conductive layer peelable from the support on the support, a cured layer of a radiation curable material on the transparent conductive layer, and a heat-meltable resin layer on the cured layer The cured product layer of the radiation curable material has a thickness of 0.5 to 7.0 μm, the hot-melt resin layer has a thickness of 0.5 to 5.0 μm, The transparent conductive layer prepares a conductive film for in-mold molding containing conductive fine particles and a cured product of the radiation curable material impregnated between the conductive fine particles,
The conductive film is set so that the support surface faces one mold surface in the injection mold, and a cavity is formed between the heat-meltable resin layer surface of the film and the other mold surface. And then clamp
Injecting molten resin into the cavity, cooling, molding a plastic molded product body, and laminating and integrating the transparent conductive layer on the surface of the molded product body,
The manufacturing method of the plastic molded product with a transparent conductive layer including this.

  (8) The method for producing a plastic molded article according to the above (7), wherein the plastic molded article with a transparent conductive layer is obtained by providing a transparent conductive layer on the curved surface of the molded article body.

  In the present invention, the “transparent conductive layer that is peelable from the support” means that the support and the transparent conductive layer are peelable from each other. When the in-mold transfer conductive film of the present invention is actually used, the support may be peeled off from the conductive layer laminated and integrated on the surface of the molded product body, or the thin molded product body The conductive layer laminated and integrated on the surface may be peeled off from the support together with the molded product.

  In the conductive film for in-mold molding of the present invention, the transparent conductive layer contains conductive fine particles and a cured product of a radiation curable material impregnated between the conductive fine particles. For this reason, the transparent conductive layer is excellent in flexibility and can follow strain deflection, and cracks are also generated in the transparent conductive layer due to film deformation under a high temperature environment during in-mold molding. It does not occur. Furthermore, the cured product of the radiation curable material impregnated between the conductive fine particles serves to fix the positional relationship between the conductive fine particles in the transparent conductive layer and maintain the contact between the conductive fine particles. Therefore, the electrical resistance value of the transparent conductive layer imparted to the molded product can be kept low even through a high temperature environmental process during in-mold molding.

  In the in-mold molding conductive film of the present invention, the in-mold molding heat-melting resin layer and the injected molten resin are in contact with each other and welded. The adhesion with the layer is very good.

  By performing in-mold molding using the conductive film for in-mold molding of the present invention, a plastic molded product body is molded, and a transparent conductive layer of the conductive film is laminated and integrated on a desired surface of the molded product body. can do. The obtained transparent conductive layer is excellent in flexibility and does not crack even in a high temperature environment during in-mold molding. Furthermore, the electrical resistance value of the transparent conductive layer imparted to the molded product is kept low.

  Moreover, since the heat-meltable resin layer and the molded product body are welded, the adhesion between the molded product body and the transparent conductive layer is very good. Even if the surface of the molded product body to which the transparent conductive layer is to be applied is not flat but curved, the transparent conductive layer can be applied satisfactorily without causing cracks.

  Thus, according to this invention, the electroconductive film for transfer used suitably in order to manufacture the plastic molded product with a transparent conductive layer by in-mold molding is provided. Although this conductive film for transfer is suitably used for in-mold molding, it can be used not only for in-mold molding but also for other applications in which thermal transfer is performed via a hot-melt resin layer. Moreover, according to this invention, the method of manufacturing simply the plastic molded product with a transparent conductive layer with a low electrical resistance value by in-mold molding using the said electroconductive film for transfer is provided.

  The present invention includes an electroluminescence panel electrode, an electrochromic element electrode, a liquid crystal electrode, a transparent surface heating element, a transparent electrode such as a touch panel, an electric paper, a capacitance switch, and a display with a transparent electromagnetic wave shielding layer (such as a CRT). ) And the like.

  The present invention will be described with reference to the drawings. First, the transfer conductive film of the present invention will be described.

  FIG. 1 is a cross-sectional view showing an example of the transfer conductive film of the present invention. In FIG. 1, a conductive film (10) is formed on a support (1) with a release layer (2), a transparent conductive layer (3), a cured material layer (4) of a radiation curable material, and a heat-meltable resin layer ( 5) in this order. The release layer (2) is an arbitrary layer for facilitating the release from the transparent conductive layer (3).

  The support (1) is a flexible resin film. Examples of the resin film include polyester films such as polyethylene terephthalate (PET), polyolefin films such as polyethylene and polypropylene, polycarbonate films, nylon films, acrylic films, cellophane films, norbornene films (manufactured by JSR Corporation, Arton, etc.), etc. Is mentioned. The thickness of the support (1) is, for example, 5 to 100 μm, and preferably 15 to 75 μm in consideration of handling properties and molding stability.

  On the support (1), a release layer (2) is formed in the illustrated example. The peeling layer (2) is an arbitrary layer for facilitating peeling between the conductive layer (3) integrated with the molded body after in-mold molding and the peeling layer (2). It is good to set it as a hard resin layer (for example, pencil hardness 2H or more and 4H or less).

  The release layer (2) can be formed by applying a solution prepared by dissolving a material generally known as a hard coat agent in a solvent, if necessary, on the support (1), drying and curing. . The hard coat agent is not particularly limited, and various known hard coat agents can be used. For example, silicone-based, acrylic-based, melamine-based thermosetting hard coat agents can be used. Among these, the silicone-based hard coat agent is excellent in that high hardness can be obtained.

  Further, an ultraviolet curable hard coat agent such as an unsaturated polyester resin-based or acrylic-based radical polymerizable hard coat agent or an epoxy-based or vinyl ether-based cationic polymerizable hard coat agent may be used. The ultraviolet curable hard coat agent is preferable from the viewpoint of productivity such as curing reactivity. Among these, in view of curing reactivity and surface hardness, an acrylic radical polymerizable hard coating agent is desirable.

  The hard coat agent may be applied by a known method such as a gravure cylinder, reverse roll coater, Mayer bar, slit die coater or the like.

After application, it is dried in an appropriate temperature range and then cured. In the case of a thermosetting hard coat agent, appropriate heat is applied. For example, in the case of a silicone type hard coat agent, it is cured by heating to about 60 to 120 ° C. for 1 minute to 48 hours. In the case of an ultraviolet curable hard coat agent, it is cured by irradiating with ultraviolet rays. The ultraviolet irradiation may be performed by using a lamp such as a xenon lamp, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a carbon arc lamp, or a tungsten lamp to irradiate about 200 to 2000 mJ / cm ² . The thickness of the release layer (2) is, for example, about 0.5 to 20 μm, preferably about 0.5 to 2 μm.

  When the release layer (2) is not provided, the surface on the conductive layer (3) side of the support (1) is formed on the conductive layer (3) and the support (1 In order to facilitate the separation from the above, it is preferable that the separation treatment is performed. For example, a silicone release agent may be applied.

  A transparent conductive layer (3) is formed directly on the support (1) or on the release layer (2) on the support (1). In the present invention, conductive fine particles selected from various conductive fine particles are used for forming the conductive layer (3).

  In the production of the transparent conductive layer, indium oxide, tin-doped indium oxide (ITO), gallium-doped indium oxide, zinc-doped indium oxide, tin oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), zinc oxide Conductive inorganic fine particles such as aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), fluorine-doped zinc oxide, indium-doped zinc oxide, boron-doped zinc oxide, and cadmium oxide are used. ITO is preferable in that it provides better conductivity. Or what coated inorganic material, such as ATO and ITO, on the surface of fine particles which have transparency, such as barium sulfate, can also be used. The particle diameter of these fine particles varies depending on the optical characteristics and electrical characteristics required depending on the use of the conductive layer, and cannot be generally specified depending on the shape of the particles, but is preferably 1.0 μm or less, more preferably 1 nm to 100 nm. Preferably, 5 nm to 100 nm is more preferable. When the particle diameter exceeds 1.0 μm, optical properties such as haze value on the surface of the conductive layer are deteriorated.

  In the present invention, the transparent means that visible light is transmitted. Regarding the degree of light scattering, the required level varies depending on the use of the conductive layer. In the present invention, those having scattering, which is generally referred to as translucent, are also included.

  In the present invention, a liquid in which conductive fine particles selected from the various conductive fine particles according to the purpose are dispersed is used as the conductive paint. This conductive paint is applied directly on the support (1) or on the release layer (2) on the support (1) and dried to form a conductive fine particle-containing layer. Thereafter, the conductive fine particle-containing layer is compressed to form a compressed layer of conductive fine particles to obtain a conductive layer (3).

  The liquid in which the conductive fine particles are dispersed is not particularly limited, and various known liquids can be used, and water or a polar organic solvent having an affinity for water is preferable. Particularly preferred are alcohols such as methanol, ethanol and isopropyl alcohol, and amides such as N, N-dimethylformamide, N-methylpyrrolidone (NMP) and N, N-dimethylacetamide. These liquids can be used singly or as a mixture of two or more. Moreover, a dispersing agent can also be used according to the kind of liquid.

  The amount of the liquid to be used is not particularly limited, and the dispersion liquid of the conductive fine particles may have a viscosity suitable for coating. For example, the amount is about 100 to 100,000 parts by weight of liquid with respect to 100 parts by weight of conductive fine particles. It is good to select suitably according to the kind of electroconductive fine particles and liquid.

  The dispersion of the conductive fine particles in the liquid may be performed by a known dispersion method. Among these, dispersion by a media mill is preferable. Conventionally used glass beads, alumina beads, titania beads, zirconia beads and the like can be used as the dispersion medium, and zirconia beads are most suitable. Dispersion media tend to increase the dispersibility as the diameter decreases. When the dispersion of the conductive fine particles is excessively dispersed, the conductivity of the obtained conductive layer tends to be deteriorated. On the other hand, when the dispersion is insufficient, the surface of the obtained conductive layer tends to be rough. A dispersion medium having a diameter of about 0.03 to 1.0 mm may be used.

  The dispersion of conductive fine particles preferably does not contain a resin. That is, it is preferable that the resin amount = 0. If no resin is used, contact between the conductive fine particles is not inhibited by the resin in the conductive layer. Therefore, the conductivity between the conductive fine particles is ensured, and the electric resistance value of the obtained conductive layer is low. It is possible to include a resin as long as it does not impair the conductivity. For example, the upper limit of the content of the resin in the dispersion is expressed by the volume before dispersion, and the volume of the conductive fine particles is expressed as follows. When 100, the volume is less than 25, preferably 19 or less. When an amount of resin that plays a role as a binder is used, contact between the conductive fine particles is inhibited by the binder, electron transfer between the fine particles is inhibited, and conductivity is lowered.

  Thus, it is preferable not to use a resin in the conductive layer during compression (that is, in a dispersion of conductive fine particles), and even if used, a small amount is preferable. The amount of resin to be used may be appropriately determined because it can vary to some extent depending on the purpose of the conductive layer.

A dispersion of conductive fine particles is applied directly on the support (1) or on the release layer (2) on the support (1) and dried to form a conductive fine particle-containing layer.
The application of the conductive fine particle dispersion is not particularly limited and can be performed by a known method. For example, it can be performed by a coating method such as a reverse roll method, a direct roll method, a blade method, a knife method, an extrusion nozzle method, a curtain method, a gravure roll method, a bar coat method, a dip method, a kiss coat method, or a squeeze method.

  Next, the formed conductive fine particle-containing layer is compressed to obtain a compressed layer (3) of conductive fine particles. By compressing, the strength of the film is improved. That is, by compressing, the contact points between the conductive fine particles increase and the contact surface increases. For this reason, the coating strength increases and the electrical resistance decreases.

The compression is preferably performed with a compressive force of 44 N / mm ² or more. If the pressure is less than 44 N / mm ² , the conductive fine particle-containing layer cannot be sufficiently compressed, and it is difficult to obtain a conductive layer having excellent conductivity. 135N / mm ² or more compressive force and more preferably, compressive force of 180 N / mm ² is more preferable. The higher the compressive force, the better the coating film strength and the more excellent the conductivity. Since the pressure resistance of the apparatus has to be increased as the compressive force is increased, generally a compressive force of up to 1000 N / mm ² is appropriate. The compression is not particularly limited and can be performed by a sheet press, a roll press, or the like, but is preferably performed using a roll press machine. Details of the compression are described in the above-mentioned JP-A-2002-347150 and JP-A-2003-16842.

  In this way, a compressed layer (3) of conductive fine particles is formed. The thickness of the conductive fine particle compressed layer (= thickness of the transparent conductive layer) may be about 0.05 to 5 μm, preferably 0.1 to 3 μm, although it depends on the application. If the thickness is less than 0.05 μm, the surface resistance value is increased in the molded product after in-mold molding. On the other hand, if the thickness exceeds 5 μm, the optical characteristics such as a decrease in total light transmittance are likely to be deteriorated.

  The formed conductive fine particle compression layer (3) is a porous layer, and voids exist between the conductive fine particles.

  On the compressed layer (3) of conductive fine particles, a radiation curable material is applied and dried, and the radiation curable material is impregnated between the conductive fine particles, and the radiation curable material is applied on the compressed layer (3). Forming a layer. After that, radiation irradiation (electron beam, ultraviolet ray, etc.) is performed to cure the radiation curable material impregnated between the conductive fine particles, and the radiation curable material forming the layer is cured to cure the radiation. A cured product layer (4) of the functional material is obtained.

  Transparent with excellent flexibility consisting of compressed conductive fine particles and a cured product of the impregnated radiation curable material by impregnating and curing the radiation curable material between the conductive fine particles in the compressed layer (3) A conductive layer (3) is obtained. The impregnation with the radiation curable material is performed after the conductive fine particle compression layer (3) is formed, i.e., after the conductive fine particles are joined to each other by a compression operation to ensure conductivity. The conductivity of the conductive layer (3) is high. In addition, since the voids between the conductive fine particles are filled with the cured product of the radiation curable material, the compressed state of the conductive fine particles in the transparent conductive layer (3) is maintained, and the positional relationship between the conductive fine particles is fixed. Thus, the contact between the conductive fine particles is reliably maintained. For this reason, the electrical resistance value of the transparent conductive layer imparted to the molded product is kept low even through a high temperature environmental process during in-mold molding.

  The thickness of the cured product layer (4) of the radiation curable material may be about 0.1 to 10 μm, and preferably 0.5 to 7.0 μm. If the thickness is less than 0.1 μm, the amount of impregnation of the radiation curable material into the compressed layer (3) may be small, and the gap between the conductive fine particles may not be filled with the cured product of the radiation curable material. is there. For this reason, the above-described contact between the conductive fine particles is insufficiently maintained, and there is a concern that the electrical resistance value of the conductive layer is increased by a high-temperature environmental process during in-mold molding. On the other hand, when the thickness exceeds 10 μm, the amount of impregnation of the radiation curable material into the compression layer (3) is sufficient, and the effect of suppressing the increase in the electric resistance value of the conductive layer is saturated.

  The radiation curable material is selected from optically transparent ultraviolet curable materials and electron beam curable materials.

  The radiation curable material is preferably composed of an ultraviolet (electron beam) curable compound or a composition for polymerization thereof. Examples of such compounds include (meth) acrylic double bonds such as ester compounds of acrylic acid and methacrylic acid, epoxy acrylate and urethane acrylate; allylic double bonds such as diallyl phthalate; Mention may be made of monomers, oligomers, polymers, and the like that contain or introduce reactive double bond groups in the molecule that generate radicals by irradiation with ultraviolet rays or electron beams such as saturated double bonds, and are crosslinked or polymerized. These are preferably polyfunctional, particularly trifunctional or higher, and may be used alone or in combination of two or more. Moreover, you may use a monofunctional thing as needed.

  As the ultraviolet (electron beam) curable monomer, a compound having a molecular weight of less than 2000 is preferable, and as the oligomer, a monomer having a molecular weight of 2000 to 10,000 is preferable. These include styrene, ethyl acrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol methacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, etc. Preferred examples include pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate, phenol ethylene oxide Examples include adduct (meth) acrylate. In addition, examples of the ultraviolet curable oligomer include oligoester acrylate and an acrylic modified product of urethane elastomer.

  In addition, (meth) acrylic double resin can be applied to resins such as acrylic resin, silicone resin, fluoropolymer, polyethylene resin, cycloolefin resin, polyurethane resin, polyester resin, and polyether resin by a known method. Those in which a bond is introduced and subjected to radiation sensitive modification can be used.

  The radiation curable material may contain a known photopolymerization initiator. The photopolymerization initiator is not particularly required when an electron beam is used as radiation, but is required when ultraviolet rays are used. The photopolymerization initiator may be appropriately selected from ordinary ones such as acetophenone, benzoin, benzophenone, and thioxanthone. Among the photopolymerization initiators, examples of the photo radical initiator include Darocur 1173, Irgacure 651, Irgacure 184, and Irgacure 907 (all manufactured by Ciba Specialty Chemicals). The content of the photopolymerization initiator is, for example, about 0.5 to 5% by weight with respect to the ultraviolet curable component.

  Moreover, the composition containing an epoxy compound and a photocationic polymerization catalyst is also used as a radiation curable material.

  The application of the radiation curable material may be performed by a known method such as a roll coater such as a gravure cylinder or reverse, a Mayer bar, or a slit die coater. Further, at the time of application, in order to better impregnate between the conductive fine particles of the compression layer (3), the viscosity of the radiation curable material may be adjusted by diluting with an appropriate solvent.

  On the cured layer (4) of the radiation curable material, a hot-melt resin is applied and dried to form a hot-melt resin layer (5). By forming the heat-meltable resin layer (5), the heat-meltable resin layer (5) and the injected molten resin are in contact and welded during in-mold molding. Adhesion is very good.

  The heat-meltable resin is a resin that is solid at normal temperature (25 ° C.) and melts by heat. The heat-meltable resin is optically transparent as long as it is in a molten state at a temperature of 90 ° C. or higher.

  The heat-meltable resin is not particularly limited, and is a known polyester resin, acrylic resin, epoxy resin, polycarbonate resin, olefin resin, nitrified cotton resin, polyurethane resin, chlorinated rubber resin, Polyamide resins, vinyl chloride-vinyl acetate copolymers and the like can be used. Among these, resins having good compatibility with the resin for molded products are preferable. Those having a melt viscosity of 100 to 10,000 dPa · s / 200 ° C. are preferred. A heat-meltable resin has a crystalline melting point and a structurally high cohesive force, and therefore has a feature that it is hardly soluble in a general-purpose organic solvent. Therefore, it is generally used in the form of a suspension emulsion in water, water / organic solvent, or organic solvent. However, depending on the degree of cohesive force, there are also hot-melt resins that are soluble in organic solvents.

  Application of the heat-meltable resin may be performed by a known method such as a gravure cylinder, reverse roll coater, Mayer bar, slit die coater or the like. After coating, the resin is dried in an appropriate temperature range lower than the melting temperature of the resin to form a hot-melt resin layer (5). The thickness of the heat-meltable resin layer (5) is preferably from 0.1 to 50 μm, more preferably from 0.5 to 5.0 μm. In the heat-meltable resin layer (5), at least the surface layer resin of the layer (5) is welded in contact with the injected molten resin during in-mold molding, and the molded product body and the transparent conductive layer have good adhesion. Plays the role of joining. For this purpose, the thickness of the heat-meltable resin layer (5) is preferably 0.1 μm or more. On the other hand, if it exceeds 50 μm, the effect of joining is saturated.

  As described above, the transfer conductive film of the present invention is obtained. Note that the surface of the heat-meltable resin layer (5) may be protected with an appropriate release paper before using the transfer conductive film.

  Next, a method for producing a plastic molded product with a transparent conductive layer by in-mold molding using the conductive film for transfer will be described.

  FIG. 2 is a schematic cross-sectional view for explaining a method for producing a plastic molded article with a transparent conductive layer by in-mold injection molding using the transfer conductive film of the present invention. FIG. 3 is a cross-sectional view of the obtained plastic molded article with a transparent conductive layer.

  2A shows a state before the start of injection molding, FIG. 2B shows a state where the mold is closed, and FIG. 2C shows a state after injection molding. The injection mold has a cavity (34) that matches the shape of a molded product desired to be manufactured when the fixed mold (31) and the movable mold (32) are closed.

  Referring to (A), between the fixed mold (31) and the movable mold (32), the transfer conductive film (10) of the present invention has the support (1) surface of the movable mold (32). The mold surface (32a) faces and the heat-meltable resin layer (5) surface faces the mold surface (31a) of the fixed mold (31) and is positioned. The detailed layer structure of the film (10) is not shown. Referring to (B), the conductive film (10) is sucked from the mold surface (32a) side of the movable mold (32), and the fixed mold (31) and the movable mold (32) are closed. The molten resin is injected from the injection gate (33) into the cavity (34) and cooled. Referring to (C), the movable mold (32) is moved, and the molded product (20) having the conductive layer (3) attached to one side of the molded product body (21) is taken out.

  In this manner, a molded product (20) in which the transparent conductive layer (3) is laminated and integrated on a desired surface of a molded product body (21) having a desired shape can be easily obtained.

  Referring to FIG. 3, the obtained plastic molded article with a transparent conductive layer (20) is such that at least the surface layer resin of the heat-meltable resin layer (5) of the conductive film (10) is in-mold molded. The molded resin body (21) and the transparent conductive layer (3) are bonded to each other with very good adhesion. In FIG. 3, the interface between the layer (5) and the molded article body (21) is indicated by a broken line for convenience, but it is considered that such an interface does not actually exist. Since the cured product of the impregnated radiation curable material exists in the space between the conductive fine particles in the obtained transparent conductive layer (3), the transparent conductive layer (3) is excellent in flexibility. Even if the surface of the molded product body is curved, cracks do not occur, the contact between the conductive fine particles is reliably maintained, and the electrical resistance value of the transparent conductive layer applied to the molded product is low Maintained. Excellent durability even during use of molded products. Furthermore, the transparent conductive layer (3) has a small haze and excellent optical properties.

  As the resin for forming the molded article main body, various kinds of resins conventionally used such as acrylic resins, polycarbonate resins, olefin resins, and the like may be used depending on the application.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

[Example 1]
(Conductive film for transfer)
First, the conductive film for transfer shown in FIG. 1 was produced.

  A 50 μm thick PET film HPE (manufactured by Teijin DuPont Films) was used as the support (1). A silicone hard coat solution KP-854 (manufactured by Shin-Etsu Chemical Co., Ltd.) is applied onto the easy-contact surface of the PET film (1), dried, and cured in a 60 ° C. environment for 48 hours, 1.0 μm. A thick release layer (2) was formed.

  300 parts by weight of ethanol was added to 100 parts by weight of ITO fine particles (manufactured by DOWA Electronics Co., Ltd.) having a primary particle size of 26 nm, and the media was dispersed as zirconia beads with a disperser. The obtained ITO coating solution was applied onto the release layer (2) of the PET film (1) using a bar coater, dried by sending hot air of 50 ° C., and an ITO fine particle-containing layer was formed. The thickness of the ITO fine particle-containing layer was 1.5 μm. The obtained film is called an ITO film before compression.

The pre-compression ITO film was sandwiched between metal rolls and compressed using a roll press machine equipped with a pair of metal rolls having a diameter of 140 mm (the roll surface was subjected to hard chrome plating). The compression pressure was 183 N / mm ² (linear pressure: 330 N / mm, compression width: 1.8 mm), and the feed rate was 5 m / min. In this way, a compressed layer (3) of ITO fine particles was formed. The thickness of the compressed layer (3) was 1.0 μm.

  At this time, the surface electrical resistance value of the compressed layer (3) was measured and found to be 450Ω / □. The surface electrical resistance (four probe method) was measured according to JIS K7194 using a Loresta GP manufactured by Mitsubishi Chemical Corporation.

  As a radiation curable material, an acrylic resin solution having a reactive double bond (monomer component: dipentaerythritol hexaacrylate manufactured by Shin-Nakamura Chemical Co., Ltd., solvent: MEK (methyl ethyl ketone), reaction initiator: Irgacure 184 (acrylic monomer) 3% by weight with respect to the components), and the solid content concentration of the solution: 20% by weight).

  On the compression layer (3), the acrylic resin solution is applied so as to have a cured thickness of 3.0 μm, dried, and then irradiated with ultraviolet rays to be cured, and a cured product layer (4 ) Formed. In this operation, the acrylic resin solution was impregnated into the compressed layer (3) and cured.

  After drying the heat-meltable urethane-modified copolymer polyester resin solution [composition: 12 parts by weight of urethane-modified copolymer polyester (Tg = 83 ° C.), 44 parts by weight of methyl ethyl ketone, 44 parts by weight of toluene] on the cured product layer (4). Was applied to a thickness of 1.0 μm, dried by sending warm air at 80 ° C. to obtain a hot-melt resin layer (5). In this way, a conductive film for transfer (10) was produced.

(Substrate with transparent conductive layer)
Next, using the conductive film for transfer (10), in-mold molding was performed by the operation shown in FIG. 2 to produce a substrate with a transparent conductive layer having a thickness of 2.0 mm.

  Between the fixed mold (31) and the movable mold (32), the conductive film (10) is placed, and the support (1) surface faces the mold surface (32a) of the movable mold (32). (5) The surface was arranged so as to face the mold surface (31a) of the fixed mold (31). Next, the conductive film (10) was sucked from the mold surface (32a) side of the movable mold (32), and the fixed mold (31) and the movable mold (32) were closed. Subsequently, Arton resin (ARTON F4520 manufactured by JSR Corporation) melted at 270 to 330 ° C. was injected and injected from the injection gate (33) into the cavity (34), and cooled to prepare a substrate. A uniform transparent conductive layer was formed on the substrate surface. 2 and 3 exemplify substrates having curved surfaces, it goes without saying that substrates having various shapes can be manufactured.

(Surface electrical resistance (four probe method))
Using a Loresta GP manufactured by Mitsubishi Chemical Corporation, the surface electrical resistance value of the obtained transparent conductive layer was measured according to JIS K7194, and found to be 450Ω / □.

[Example 2]
As a radiation curable material, instead of the acrylic resin solution, a cycloolefin resin solution having a reactive double bond (monomer component: tricyclodecane dimethanol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., solvent: MEK, reaction) The conductive film for transfer (10) was transferred in the same manner as in Example 1 except that the initiator: Irgacure 184 (3% by weight relative to the cycloolefin monomer component) and the solid content concentration of the solution: 20% by weight were used. Produced.

  Using this transfer conductive film (10), a substrate with a transparent conductive layer was produced in the same manner as in Example 1. A uniform transparent conductive layer was formed on the substrate surface. It was 470 ohm / square when the surface electrical resistance value of the obtained transparent conductive layer was measured.

[Example 3]
As a radiation curable material, instead of the acrylic resin solution, a urethane acrylate resin solution having a reactive double bond (monomer component: UA512 manufactured by Shin-Nakamura Chemical Co., Ltd., solvent: MEK, reaction initiator: Irgacure 184 ( A conductive film for transfer (10) was prepared in the same manner as in Example 1 except that 3 wt% relative to the urethane acrylate monomer component and the solid content concentration of the solution: 20 wt%) were used.

  Using this transfer conductive film (10), a substrate with a transparent conductive layer was produced in the same manner as in Example 1. A uniform transparent conductive layer was formed on the substrate surface. It was 480 ohms / square when the surface electrical resistance value of the obtained transparent conductive layer was measured.

[Comparative Example 1]
In this comparative example, a conductive film for transfer without a cured product layer (4) of a radiation curable material was produced as follows.

  In the same manner as in Example 1, a 1.0 μm-thick release layer (2) was formed on the easy-contact surface of a 50 μm-thick PET film (1), and ITO fine particles of 1.0 μm thickness were formed on the release layer (2). The compressed layer (3) was formed.

  On the compression layer (3), the same hot-melting urethane-modified copolymerized polyester resin solution used in Example 1 was applied so that the thickness after drying was 1.0 μm, and hot air at 80 ° C. was sent. Dried. The hot-melt polyester resin was impregnated in the compression layer (3) to obtain a transparent conductive layer (3) and a hot-melt resin layer (5). Thus, a conductive film for transfer was produced.

  Using this transfer conductive film (10), a substrate with a transparent conductive layer was produced in the same manner as in Example 1. A uniform transparent conductive layer was formed on the substrate surface. When the surface electrical resistance value of the obtained transparent conductive layer was measured, it was 2200Ω / □.

[Comparative Example 2]
An ITO thin film having a thickness of 30 nm was formed on a PET film support having a thickness of 125 μm by a sputtering method to obtain a conductive film.

  This conductive film is placed between the fixed mold (31) and the movable mold (32) with the support surface facing the mold surface (32a) of the movable mold (32) and the ITO thin film surface being the mold of the fixed mold (31). It was arranged to face the surface (31a). Next, the conductive film was sucked from the mold surface (32a) side of the movable mold (32), and the fixed mold (31) and the movable mold (32) were closed. Subsequently, a molten Arton resin (manufactured by JSR Co., Ltd., ARTON F4520) was injected and injected from the injection gate (33) into the cavity (34), and cooled to prepare a substrate. Cracks occurred on the surface of the conductive layer on the substrate. Therefore, the surface electrical resistance value of the conductive layer could not be measured.

  As shown in Examples 1 to 3, when an in-mold conductive film conforming to the present invention is used, a cured product of a radiation curable material impregnated in the space between the conductive fine particles in the transparent conductive layer Therefore, the electrical resistance value of the transparent conductive layer applied to the molded product can be kept low even after a high temperature environmental process during in-mold molding. . On the other hand, in Comparative Example 1, the impregnated hot-melt polyester resin is present in the space between the conductive fine particles in the transparent conductive layer. An increase in electrical resistance was observed.

It is sectional drawing which shows an example of the electroconductive film for transfer of this invention. It is a schematic sectional drawing for demonstrating the method to manufacture the plastic molded product with a transparent conductive layer by in-mold injection molding. It is sectional drawing of a plastic molded product with a transparent conductive layer.

Explanation of symbols

(10): Conductive film for transfer
(1): Support
(2): Release layer
(3): Transparent conductive layer
(4): Cured material layer of radiation curable material
(5): Hot melt resin layer
(31): Fixed type
(32): Movable type
(33): Injection gate
(34): Cavity
(20): Molded product
(21): Molded product body

Claims (8)

A support, a transparent conductive layer peelable from the support on the support, a cured layer of a radiation curable material on the transparent conductive layer, and a heat-meltable resin layer on the cured layer Having at least
The cured product layer of the radiation curable material has a thickness of 0.5 to 7.0 μm,
The hot-melt resin layer has a thickness of 0.5 to 5.0 μm,
The transparent conductive layer is an in-mold conductive film including conductive fine particles and a cured product of the radiation curable material impregnated between the conductive fine particles.   The conductive fine particles include indium oxide, tin-doped indium oxide (ITO), gallium-doped indium oxide, zinc-doped indium oxide, tin oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), zinc oxide, and aluminum. The conductive film according to claim 1, which is selected from the group consisting of doped zinc oxide (AZO), gallium doped zinc oxide (GZO), fluorine doped zinc oxide, indium doped zinc oxide, boron doped zinc oxide, and cadmium oxide.   The conductive film according to claim 1, wherein the transparent conductive layer has a thickness of 0.05 to 5 μm. The conductive film according to any one of claims 1 to 3, wherein the heat-meltable resin has a melt viscosity of 100 to 10,000 dPa · s / 200 ° C. The conductive film according to claim 1, wherein the heat-meltable resin is a heat-meltable urethane-modified copolymer polyester resin. The conductive film for in-mold molding is
A dispersion of conductive fine particles is applied onto a support, dried, and a layer containing conductive fine particles is formed.
Compressing the conductive fine particle-containing layer to form a conductive fine particle compressed layer in which voids exist between the conductive fine particles;
On the compressed layer of the conductive fine particles, a radiation curable material is applied and dried to impregnate the radiation curable material between the conductive fine particles, and a layer of the radiation curable material is formed.
Radiation irradiation is performed to cure the radiation curable material impregnated between the conductive fine particles and the radiation curable material forming the layer,
On the cured layer of the obtained radiation-curable material, a hot-melt resin is applied and dried to form a hot-melt resin layer.
The electroconductive film of any one of Claims 1-5 which is obtained by this. A method for producing a plastic molded article with a transparent conductive layer comprising a plastic molded article main body and a transparent conductive layer applied to the surface of the molded article main body by in-mold molding,
A support, a transparent conductive layer peelable from the support on the support, a cured layer of a radiation curable material on the transparent conductive layer, and a heat-meltable resin layer on the cured layer The cured product layer of the radiation curable material has a thickness of 0.5 to 7.0 μm, the hot-melt resin layer has a thickness of 0.5 to 5.0 μm, The transparent conductive layer prepares a conductive film for in-mold molding containing conductive fine particles and a cured product of the radiation curable material impregnated between the conductive fine particles,
The conductive film is set so that the support surface faces one mold surface in the injection mold, and a cavity is formed between the heat-meltable resin layer surface of the film and the other mold surface. And then clamp
Injecting molten resin into the cavity, cooling, molding a plastic molded product body, and laminating and integrating the transparent conductive layer on the surface of the molded product body,
The manufacturing method of the plastic molded product with a transparent conductive layer including this.   The method for producing a plastic molded product according to claim 7, wherein the plastic molded product with a transparent conductive layer is obtained by providing a transparent conductive layer on a curved surface of the molded product main body.