JP7232594B2 - Method for manufacturing conductive member - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a conductive member for transferring a conductive pattern formed on a transfer base material to a transferred body.

In recent years, the development of automobiles and portable electronic devices has been remarkable, and while the demand for lighter weight, thinner, and higher strength is increasing, epoxy resins, phenolic resins, unsaturated polyesters, such as carbon fiber reinforced resins and glass fiber reinforced resins, are being used. A method of using a molded article manufactured by impregnating carbon fiber or glass fiber with a thermosetting resin such as a resin and heat-curing the resin as a housing has been studied.

In addition, we investigated the provision of a plating layer in order to improve the wear resistance and corrosion resistance of the housing made in this way, and formed a conductive metal layer or a conductive pattern such as a touch sensor or an antenna on the housing to form a composite. It is being studied to use it as a conductive member. For example, as the former, Japanese Patent Application Laid-Open No. 6-264250 (Patent Document 1) discloses a method of forming a metal layer by irradiating the surface of a carbon fiber reinforced resin molded product with low-temperature plasma to perform plating. Since the equipment is expensive and plating is required, there are many processes and it is complicated.

Further, for example, Japanese Unexamined Patent Application Publication No. 2014-192275 (Patent Document 2) describes a substrate having a porous layer serving as an ink-receiving layer on a support and a layer containing colloidal silica as a main component on the porous layer. Disclosed is a method for transferring a conductive pattern, in which a conductive pattern is formed thereon, and the conductive pattern is transferred to the adhesive surface of a transfer-receiving body provided with a sticky adhesive layer or a pressure-sensitive adhesive layer on a support. A conductive member can be manufactured by attaching this transferred material to a housing, but there has been a demand for further improvement in terms of adhesion of the conductive pattern.

JP-A-6-264250 JP 2014-192275 A

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a conductive member which is simple in process and has good pattern adhesion.

The above objects of the present invention have been basically achieved by the following inventions.
A conductive pattern is formed on the release layer of a transfer substrate having at least a porous layer on a support and a release layer containing zirconium oxide as inorganic fine particles or fluororesin as organic fine particles on the porous layer. A conductive member comprising at least the steps of: transferring the conductive pattern obtained in the above step to a transfer-receiving material having adhesiveness at room temperature; and heating and curing the transfer-receiving material to which the conductive pattern has been transferred. Production method.

According to the present invention, it is possible to provide a method for manufacturing a conductive member in which the steps are simple and the adhesion of the pattern is good.

1 is a schematic view of a transfer substrate on which a conductive pattern is formed according to the present invention; FIG. FIG. 2 is a schematic view of bonding a transfer substrate on which a conductive pattern is formed and a transfer target according to the present invention. Schematic diagram of a conductive member in the present invention. FIG. 4 is another schematic diagram of a conductive member according to the present invention;

The present invention will be described in detail below.

A method for producing a conductive material according to the present invention will be described with reference to the drawings. First, a transfer substrate 10 having a porous layer 2 and a dissociation layer 3 on a support 1 is prepared (FIG. 1). Next, a conductive pattern 4 is formed on the transfer substrate 10 by printing with, for example, an ink jet printer (FIG. 1). Subsequently, the conductive pattern 4 formation surface of the transfer base material 10 is pasted to the transfer material 5 which is sticky at room temperature (FIG. 2). Thereafter, the bonded transfer base material 10 is peeled off, and the transfer target body 5 to which the conductive pattern 4 has been transferred is heat-cured, or the transfer target body 5 is heat-cured before the transfer base material 10 is peeled off. Then, by peeling off the transfer substrate 10, the conductive member of the present invention as shown in FIGS. 3 and 4 can be manufactured.

The substrate for transfer in the present invention has at least a porous layer on a support and a release layer on the porous layer. It is a base material used for transferring the conductive pattern to a transfer body. The porous layer and the dissociation layer may be provided on both sides of the support, if desired.

Examples of the support that the transfer substrate has include polyolefin resins such as polyethylene and polypropylene, vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers, epoxy resins, polyarylates, polysulfones, and polyethersulfones. , polyimide, fluorine resin, phenoxy resin, triacetyl cellulose, polyethylene terephthalate, polyimide, polyphenylene sulfide, polyethylene naphthalate, polycarbonate, acrylic resin represented by polymethyl methacrylate, cellophane, nylon, polystyrene resin, ABS resin, etc. Films made of resin, quartz glass, non-alkali glass, crystallized transparent glass, various glasses such as Pyrex (registered trademark), paper, non-woven fabric, cloth, various metals, various ceramics, etc. can be mentioned, but are not limited to these. not something. In addition, these supports can be appropriately combined depending on the application. For example, polyolefin resin-coated paper obtained by laminating paper with polyolefin resin can be used.

Among these, paper, polyolefin resin-coated paper, and films made of polyolefin resin, triacetyl cellulose, polyethylene terephthalate, and polycarbonate are preferable from the viewpoint of cost and versatility.

Among the above supports, when non-absorbent supports such as films made of various resins, glass, and polyolefin resin-coated paper are used, the adhesion between the non-absorbent support and the porous layer is improved. Therefore, it is preferable to provide a known undercoat layer composed of gelatin, various urethane resins, polyvinyl alcohol, etc. between the support and the porous layer. Further, for example, a polyethylene terephthalate film is commercially available in a state in which an undercoat layer is provided in advance as an easy adhesion treated product, and this may be used. It is also preferable to improve the wettability of the support by corona treatment or plasma treatment.

The solid content coating amount of the undercoat layer is preferably 0.5 g/m ² or less, more preferably 0.3 g/m ² or less, and still more preferably 0.1 g/m ² or less. The lower limit is desirably 0.01 g/m ² or more.

In the present invention, the porous layer of the transfer base material has a function of absorbing a solvent component such as water or an organic solvent contained in ink or paste containing conductive fine particles suitable for forming a conductive pattern, which will be described later.

In the present invention, the porous layer of the transfer base material is preferably a layer mainly containing fine particles from the viewpoint of absorbing the solvent component. Containing mainly fine particles means that the ratio of fine particles to the total solid content of the porous layer is 50% by mass or more, preferably 70% by mass or more. A wide variety of known fine particles can be used as the fine particles. For example, light calcium carbonate, ground calcium carbonate, magnesium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, Amorphous synthetic silica, alumina, colloidal alumina, alumina hydrate, lithopone, zeolite, hydrated halloysite, inorganic fine particles such as magnesium hydroxide, acrylic or methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyester resin , styrene/acrylic resin, styrene/butadiene resin, styrene/isoprene resin, methyl methacrylate/butyl methacrylate resin, polycarbonate resin, silicone resin, urea resin, melamine resin, epoxy resin, phenol resin, Examples include organic fine particles such as diallyl phthalate-based resins. Examples of the organic fine particles include spherical or amorphous nonporous or porous organic fine particles made of at least one of the resins described above. Of course, one or more of the inorganic fine particles and one or more of the organic fine particles can be used in combination. Among the above, it is preferable to contain inorganic fine particles from the viewpoint of solvent component absorption, such as light calcium carbonate, heavy calcium carbonate, kaolin, talc, magnesium carbonate, amorphous synthetic silica, alumina, and alumina hydrate. is more preferred, and amorphous synthetic silica, alumina, and alumina hydrate are particularly preferred. Further, when flexibility is required for the substrate for transfer in the present invention, it is particularly preferable to contain alumina hydrate.

Amorphous synthetic silica can be broadly classified into wet process silica, gas phase process silica and others according to the production method.

Wet-process silica is further classified into precipitation-process silica, gel-process silica, and sol-process silica according to the production method. Precipitation silica is produced by reacting sodium silicate and sulfuric acid under alkaline conditions, and the grown silica particles are aggregated and sedimented, and then filtered, washed with water, dried, pulverized, and classified into products. Examples of precipitation silica include Nip Seal (registered trademark) from Tosoh Silica Corporation, Tokusil (registered trademark) from Tokuyama Corporation, and Mizukasil (registered trademark) from Mizusawa Chemical Industry Co., Ltd. Trademark). Gel silica is produced by reacting sodium silicate and sulfuric acid under acidic conditions. During aging, the fine particles dissolve and re-precipitate to bind other primary particles together, so that well-defined primary particles disappear and form relatively hard agglomerated particles with an internal void structure. For example, it is commercially available as Nipgel (registered trademark) from Tosoh Silica Corporation, Syloid (registered trademark) and Sirojet (registered trademark) from Grace Japan, and Mizukasil from Mizusawa Chemical Industry Co., Ltd. In the present invention, it is preferable to use precipitated silica or gel silica, and precipitated silica is more preferred.

The wet-process silica particles are preferably wet-process silica particles having an average primary particle size of 50 nm or less, preferably 3 to 40 nm, and an average aggregate particle size of 1 to 50 μm. Further, it is more preferable to disperse the wet-process silica particles having an average agglomerated particle size of 5 to 50 μm so that the average secondary particle size is 500 nm or less. The average secondary particle size of the dispersed wet-process silica is more preferably 10 to 300 nm, still more preferably 20 to 200 nm. As a dispersing method, a wet dispersion method of mechanically pulverizing wet silica dispersed in an aqueous medium is preferably used, and a media mill such as a bead mill is preferably used for this. The bead mill grinds pigments by colliding with beads packed in a closed vessel. It is commercially available from Tech Co., Ltd. under the name Starmill®. After dispersing using a media mill or the like, it is preferable to further disperse using a pressure-type disperser such as a high-pressure homogenizer or an ultrahigh-pressure homogenizer, an ultrasonic disperser, a thin-film orbital disperser, or the like.

Here, the average primary particle size as referred to in the present invention is obtained by observing fine particles with an electron microscope and determining the average particle size by taking the diameter of a circle equal to the projected area of each of 100 primary particles existing within a certain area as the particle size. It is. The average secondary particle size can be obtained by photographing with a transmission electron microscope. It can be measured as a number median diameter. Also, the average aggregate particle size indicates the average particle size of wet silica supplied as powder, and can be determined by, for example, the Coulter counter method.

Vapor-phase silica is also called a dry method as opposed to a wet method, and is generally produced by a flame hydrolysis method. Specifically, a method of burning silicon tetrachloride with hydrogen and oxygen is generally known, but instead of silicon tetrachloride, silanes such as methyltrichlorosilane and trichlorosilane can also be used alone or with silicon tetrachloride. It can be used in a mixed state with Vapor-phase silica is commercially available from Nippon Aerosil Co., Ltd. as Aerosil (registered trademark), and from Tokuyama Corporation as QS type.

In the present invention, the average primary particle size of the fumed silica contained in the porous layer is preferably 40 nm or less, more preferably 15 nm or less. More preferably, it has an average primary particle diameter of 3 to 15 nm and a specific surface area of 200 m ² /g or more (preferably 250 to 500 m ² /g) as determined by the BET method.

The BET method referred to in the present invention is one of methods for measuring the surface area of powders by a gas phase adsorption method, and is a method for determining the total surface area of 1 g of a sample, that is, the specific surface area, from the adsorption isotherm. Nitrogen gas is generally used as the adsorbed gas, and the method of measuring the amount of adsorption from changes in the pressure or volume of the gas to be adsorbed is most often used. The Brunauer-Emmett-Teller equation, which is called the BET equation and is widely used to determine the surface area, is the most famous for expressing the isotherm of multimolecular adsorption. The amount of adsorption is determined based on the BET formula and multiplied by the area occupied by one adsorbed molecule on the surface to obtain the surface area.

Even when vapor-phase silica is used, it is preferable to disperse it to have an average secondary particle size of 500 nm or less, as with wet-process silica. The average secondary particle size of the dispersed fumed silica is more preferably 10 to 300 nm, still more preferably 20 to 200 nm. Dispersion methods include pre-mixing gas-phase silica and a dispersion medium mainly composed of water by conventional propeller stirring, turbine-type stirring, homomixer-type stirring, etc., followed by media mills such as ball mills, bead mills and sand grinders, Dispersion is preferably carried out using a pressure-type disperser such as a high-pressure homogenizer or an ultra-high-pressure homogenizer, an ultrasonic disperser, a thin-film orbital disperser, or the like.

In the present invention, it is convenient and preferable to form the porous layer by applying a coating solution containing the fine particles described above on the support and drying the coating solution. Therefore, in preparing such a coating liquid, it is preferable to produce a slurry of wet-process silica or gas-phase silica having an average secondary particle size of 500 nm or less, and in producing the slurry, the concentration of the slurry can be increased and the dispersion stability can be improved. Various known methods may be used to obtain the For example, as described in JP-A-2002-144701 and JP-A-2005-1117, a method of dispersing in the presence of an alkaline compound, a method of dispersing in the presence of a cationic compound, and the presence of a silane coupling agent. A method of dispersing in the presence of a cationic compound is more preferable.

Examples of the cationic compound used for dispersing the above wet-process silica or vapor-phase silica include polyethyleneimine, polydiallylamine, polymers having structural units derived from diallylamine derivatives, polyallylamines, alkylamine polymers, primary to tertiary amino Polymers having groups or quaternary ammonium bases are preferably used. Polymers having structural units derived from diallylamine derivatives are particularly preferred. The molecular weight of these cationic polymers is preferably about 2,000 to 100,000, more preferably about 2,000 to 30,000, in terms of dispersibility and dispersion viscosity.

In the present invention, the alumina preferably contained in the porous layer is preferably γ-alumina, which is a γ-type crystal of aluminum oxide, and more preferably a δ-group crystal. Although γ-alumina can reduce the primary particles to about 10 nm, usually secondary particle crystals of several thousand to tens of thousands of nm are averaged by ultrasonic waves, high-pressure homogenizers, counter-impingement jet crushers, etc. Pulverized to a particle size of preferably 500 nm or less, more preferably about 20 to 300 nm, can be used.

In the present invention, the alumina hydrate preferably contained in the porous layer is represented by a constitutive formula of Al ₂ O ₃ ·nH ₂ O (n=1 to 3). Alumina hydrates are generally obtained by known production methods such as hydrolysis of aluminum alkoxides such as aluminum isopropoxide, neutralization of aluminum salts with alkali, and hydrolysis of aluminates. The average secondary particle size of alumina hydrate is preferably 500 nm or less, more preferably 20 to 300 nm.

In the present invention, the alumina and alumina hydrate preferably contained in the porous layer are used in the form of a dispersion dispersed with a known dispersant such as acetic acid, lactic acid, formic acid, and nitric acid.

In the present invention, the porous layer preferably contains a resin binder together with the fine particles described above. Examples of the resin binder include polyvinyl alcohol, silanol-modified polyvinyl alcohol, oxidized starch, etherified starch, carboxymethyl cellulose, and hydroxyethyl cellulose. cellulose derivatives, casein, gelatin, soybean protein, silyl-modified polyvinyl alcohol, etc., styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, etc. conjugated diene copolymer latex, or carboxyl groups of these various polymers Functional group-modified polymer latex with functional group-containing monomers such as melamine resin, water-based adhesive such as thermosetting synthetic resin system such as urea resin, polymethyl methacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride-acetic acid Synthetic resin adhesives such as vinyl copolymers, polyvinyl butyral, and alkyd resins can be mentioned, and these can be used singly or in combination. In addition, the use of known natural or synthetic resin binders alone or in combination is not particularly limited.

Among these, polyvinyl alcohol or silanol-modified polyvinyl alcohol is preferred, and partially or completely saponified polyvinyl alcohol or silanol-modified polyvinyl alcohol having a degree of saponification of 80% or more is particularly preferred. The average degree of polymerization of polyvinyl alcohol is preferably 200-5000.

The content of the resin binder with respect to the fine particles is not particularly limited. It is preferably in the range of to 80% by mass, more preferably in the range of 5 to 60% by mass, and particularly preferably in the range of 10 to 40% by mass.

The porous layer may also contain a hardening agent, if necessary, together with the resin binder constituting the porous layer. Specific examples of hardening agents include aldehyde compounds such as formaldehyde and glutaraldehyde, ketone compounds such as diacetyl and chloropentanedione, bis(2-chloroethyl)urea, and 2-hydroxy-4,6-dichloro-1. ,3,5-triazines, compounds with reactive halogens as described in US Pat. No. 3,288,775, compounds with reactive olefins as described in US Pat. N-methylol compounds as described in US Pat. No. 2,732,316, isocyanates as described in US Pat. No. 3,103,437, US Pat. aziridine compounds, carbodiimide compounds as described in U.S. Pat. No. 3,100,704, epoxy compounds as described in U.S. Pat. No. 3,091,537, dioxane derivatives such as dihydroxydioxane, borax, boric acid, boron There are inorganic cross-linking agents such as acid salts, etc., and these can be used singly or in combination of two or more. Although the content of the hardening agent is not particularly limited, it is preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less based on the resin binder.

When partially saponified or completely saponified polyvinyl alcohol or silanol-modified polyvinyl alcohol having a degree of saponification of 80% or more is used as the resin binder, the hardening agent is preferably borax, boric acid or borates, and boric acid is particularly preferred. The amount used is preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less, relative to polyvinyl alcohol. The lower limit is preferably 0.1% by mass or more.

In addition, preservatives, surfactants, coloring dyes, ultraviolet absorbers, antioxidants, fine particle dispersants, antifoaming agents, leveling agents, viscosity stabilizers, pH adjusters, etc. are added to the porous layer as necessary. can contain.

The porous layer may be composed of two or more layers, and in this case, the porous layers may have the same or different configurations. For example, a porous layer containing alumina hydrate may be formed on a porous layer containing wet-process silica.

The layer thickness (dry) of the porous layer is generally preferably 1 to 100 μm, more preferably 5 to 50 μm.

The porous layer is prepared by dissolving or dispersing fine particles and a resin binder in an appropriate solvent to prepare a coating liquid, and applying the coating liquid to a slide curtain method, a slide bead method, a slot die method, a direct gravure roll method, or a reverse gravure roll method. Application by method, spray method, air knife method, blade coating method, rod bar coating method, spin coating method, etc., screen printing, inkjet printing, dispenser printing, offset printing, reverse offset printing, gravure printing, flexographic printing, etc. A coating or printing method can be used to selectively coat the entire surface of the support or a required portion to form the coating. Further, after coating, the surface can be smoothed by performing a casting process in which it is pressed against a mirror surface roll, or by performing a calendering process.

The transfer base material of the present invention has a dissociation layer containing inorganic fine particles and/or organic fine particles as a main component on the porous layer described above. The release layer is a layer that separates the conductive pattern from the porous layer when the conductive pattern is transferred to the transferred material. As shown in 4, both the conductive pattern and part of the release layer can be transferred to the transferred material. A portion of the transferred release layer may be washed and removed as necessary.

The release layer in the present invention is the temperature applied to the transfer substrate when the transfer substrate is heat-cured before the transfer substrate is peeled off from the transfer substrate, which is the temperature when the transfer substrate is heat-cured. It is preferably a layer that does not melt or stick. The term "main component" means that inorganic fine particles and/or organic fine particles account for 93% by mass or more, preferably 98% by mass or more, of the total solid content of the layer.

As the inorganic fine particles contained in the dissociation layer in the present invention, a wide range of known inorganic fine particles can be used. For example, magnesium carbonate, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, aluminum silicate, calcium silicate, magnesium silicate, amorphous synthetic silica, alumina, alumina hydrate, magnesium hydroxide, cerium oxide. , zirconium oxide, niobium oxide, tin oxide, etc., and two or more of these may be used in combination.

The inorganic fine particles contained in the dissociation layer preferably have an average primary particle size of 10 to 200 nm, more preferably 20 nm or more. If the average primary particle size is less than 10 nm, the pores in the porous layer may be clogged and the absorbency may be lowered. If the average primary particle size exceeds 200 nm, the inorganic fine particles may settle in the coating solution used to form the dissociation layer, thereby interfering with coating.

As such inorganic fine particles, it is preferable to use an inorganic fine particle dispersion liquid in a colloidal state. be able to. Zirconium oxide sol is, for example, ZSL-20N from Daiichi Kigenso Kagaku Kogyo Co., Ltd., Zr100/20 from Nyacol Co., Ltd. (USA), Cerium oxide sol, for example, CEO2 (AC) from Nyacol Co., Ltd. (USA), Niobium oxide sol is commercially available, for example, from Taki Kagaku Co., Ltd. under the name Viral (registered trademark).

Colloidal silica includes a type in which particles are grown from silica sol under weak alkaline conditions, a type in which the amount of alkali is reduced by ion exchange, a type in which some of the silicon atoms in the lattice are replaced with aluminum atoms to enhance anionicity, and alumina. A type made cationic by surface treatment, a type synthesized by a sol-gel method using alkoxysilane as a raw material, and the like are exemplified, but any of them can be used. Since colloidal silica is slightly soluble in alkali, it is considered to be advantageous in terms of binding strength if alkali remains, but ion-exchanged types can also be used practically without any problems. These colloidal silicas are commercially available, for example, as Snowtex from Nissan Chemical Industries, Ltd. and Quartron (registered trademark) from Fuso Chemical Industries, Ltd.

As the organic fine particles contained in the dissociation layer in the present invention, a wide range of known organic fine particles can be used. Examples include organic fine particles such as acrylic resins, styrene resins, nylon resins, silicone resins, fluorine resins, phenol resins, acetal resins, polyimide resins, epoxy resins, polyphenylene sulfide resins, polyethersulfone resins, and polyamideimide resins. , and two or more of these may be used in combination.

The average primary particle size of the organic fine particles contained in the dissociation layer is preferably 10 to 500 nm, more preferably 20 nm or more. If the average primary particle size is less than 10 nm, the pores in the porous layer may be clogged and the absorbency may be lowered. If the average primary particle size exceeds 500 nm, the organic fine particles may settle in the coating liquid used to form the dissociation layer, which may interfere with coating.

Examples of such organic fine particles include polyamideimide resins such as Trepal (registered trademark) PAI manufactured by Toray Industries, Inc., polyethersulfone resins such as Trepal PES manufactured by Toray Industries, Inc., and fluorine resins such as Mitsui Chemmers. It is commercially available as 31-JR from Fluoro Products Co., Ltd. and D-210C from Daikin Industries, Ltd.

In the dissociation layer in the present invention, one or more inorganic fine particles and one or more organic fine particles may be used in combination. The volume ratio of the inorganic fine particles and the organic fine particles is preferably in the range of 1:9 to 9:1. Inorganic fine particles are preferably used from the viewpoint of the conductivity of the resulting conductive member.

In the present invention, components other than inorganic fine particles and/or organic fine particles contained in the dissociation layer include water-soluble resins such as polyvinyl alcohol as resin binders, latexes, hardeners for resin binders, surfactants, and the like. be able to.

In the present invention, the solid content coating amount of the release layer is preferably 0.01 g/m ² or more, more preferably 0.1 g/m ² or more. If the solid content coating amount is less than 0.01 g/m ² , the porous layer may be transferred to the transferred material. Although there is no particular upper limit for the coating amount of the solid content of the release layer, if it exceeds 10 g/m ² , the possibility of cracking the release layer containing inorganic fine particles and/or organic fine particles as a main component increases, which is not preferable.

The coating liquid for forming the dissociation layer can be applied by slide curtain method, slide bead method, slot die method, direct gravure roll method, reverse gravure roll method, spray method, air knife method, blade coating method, rod bar coating method, spin coating method, Preliminarily prepared on a support using various known coating or printing methods such as coating by an inkjet method, etc., screen printing, inkjet printing, dispenser printing, offset printing, reverse offset printing, gravure printing, printing by flexographic printing, etc. The dissociation layer can be formed by selectively coating the entire surface of the formed porous layer or a required portion. Among the reverse gravure roll methods, a method using a diagonal gravure roll (gravure roll having diagonal grooves) having a roll diameter of 100 mm or less (more preferably 20 to 80 mm) is particularly preferable.

When the solvent or dispersion medium of the coating liquid for forming the release layer in the transfer base material of the present invention is mainly water, multi-layer simultaneous coating such as a multi-layer slide curtain method, a multi-layer slide bead method, a multi-layer slot die method, and the like can be used. The porous layer and the release layer may be applied simultaneously using any available coating method. Alternatively, a tandem-type multilayer coating apparatus may be used in which a plurality of coating apparatuses are installed on a line along which the support is transported.

In the present invention, it is convenient and preferable that the conductive pattern to be transferred to the transferred material is formed using ink or paste containing conductive fine particles. As the ink or paste containing conductive fine particles used in the present invention, a wide range of known inks or pastes can be used, including silver nanoink, copper nanoink, silver paste, copper paste, aluminum paste, carbon ink, carbon paste, and the like. can be exemplified. It is preferable to use a silver nano ink containing silver ultrafine particles or a silver paste containing silver fine particles because it has excellent conductivity and the formed conductive pattern is not easily oxidized. It is particularly preferable to use a silver nanoink from the point of being able to form a pattern. Silver nano inks are commercially available, for example, from Mitsubishi Paper Mills Co., Ltd. as NBSIJ series, and silver pastes are commercially available, for example, from Fujikura Kasei Co., Ltd. as Dotite (registered trademark) series.

In the present invention, the ink or paste containing conductive fine particles is patterned by various printing methods or coating methods. For example, pattern formation using a dispenser printing method that can perform linear application, pattern formation using various types of inkjet printing methods such as thermal, piezo, micropump, and static electricity, letterpress printing methods, flexographic printing methods, lithography Patterns produced by various known printing methods such as a printing method, an intaglio printing method, a gravure printing method, a reverse offset printing method, a sheet-fed screen printing method, and a rotary screen printing method can be exemplified. In addition, using various known coating methods such as gravure roll method, slot die method, spin coating method, etc., forming a pattern as a continuous surface on the entire surface or part of the release layer of the transfer base material, intermittent coating Using a die coater or the like to form a pattern as an intermittent surface on the entire or part of the release layer of the transfer substrate, or using a dip coating method (also called a dip method) to release the transfer substrate. An ink or paste containing conductive fine particles may be applied to the entire layer. More preferable printing methods include an inkjet printing method, a flexographic printing method, a gravure printing method, a reverse offset printing method, a sheet-fed screen printing method, and a rotary screen printing method.

The ink or paste containing conductive fine particles patterned by these methods is cured or baked by heating after volatilizing the contained dispersion medium and/or after the porous layer absorbs the dispersion medium. Although it may be a conductive pattern, an ink containing metal ultrafine particles mainly made of silver is used, and a conductivity enhancer described in JP-A-2008-4375, JP-A-2008-235224, etc. is added to the porous layer. And/or it is preferably contained in the dissociation layer so that the metal ultrafine particles are chemically bonded to each other to form a conductive pattern. When the metal ultrafine particles are bonded to each other by chemical action, the resulting conductive pattern becomes porous, so the adhesive resin component on the surface of the transfer material diffuses into the conductive pattern, and the transfer material It is possible to obtain high adhesion between Examples of such conductivity enhancers include sodium chloride, potassium chloride, calcium chloride, and ammonium chloride.

In the present invention, the conductive pattern formed and held on the transfer base material is transferred to the transfer target material, which has adhesiveness at room temperature, while the adhesiveness is exhibited. The transfer is performed by laminating the conductive pattern-formed surface of the transfer base material on which the conductive pattern is formed and held, and the transfer-receiving material having adhesiveness in a state where adhesiveness is exhibited, and then It is done by peeling these off.

The room temperature in the present invention means the temperature range described in JIS Z 8703, specifically 5 to 35°C.

The object to be transferred which is sticky at room temperature in the present invention contains a resin which is soft and sticky at room temperature but hardens by heating. Thermosetting resins are known as such resins, and liquid resol-type phenolic resins, novolac-type phenolic resins, furan resins, epoxy resins, unsaturated polyester resins, amino resins, alkyd resins, and the like can be exemplified. . When these resins are used to produce a material to be transferred, in addition to thermosetting resins, curing agents such as acid curing agents and amine curing agents, phthalate esters, phosphate esters, fatty acid esters, epoxy-based curing agents, etc. Plasticizers, pigments such as powdery titanium oxide and carbon black, fillers such as aluminum hydroxide, zinc oxide and calcium carbonate, reinforcing materials such as glass fibers, carbon fibers and aramid fibers may be blended.

In particular, thermosetting resins such as epoxy resins, phenolic resins, and unsaturated polyester resins containing hardeners are impregnated into carbon fiber or glass fiber, molded into a film, and a release film or release paper is placed on both sides. Materials that are laminated and semi-cured by heating or drying are widely used as prepregs for carbon fiber reinforced resins and glass fiber reinforced resins. These materials are tacky at room temperature so that when semi-cured prepregs are layered, they are easily tacky and integrated. can be used.

In addition, for producing the prepreg, an epoxy resin sheet obtained by sheeting an epoxy resin containing a curing agent or the like is commercially available. .

A process of transferring a transfer pattern to a transfer target in the present invention will be described. The transfer-receiving material is a transfer-receiving material having adhesiveness at room temperature, and the conductive pattern is transferred in a state in which the adhesiveness is exhibited. Transfer is performed by laminating and peeling the base material for transfer and the material to be transferred. For example, when the object to be transferred is a three-dimensional object, the substrate for transfer is adhered to and peeled off from the object to be transferred. A preferred method is to press the physical pattern onto the material to be transferred. The lamination conditions are preferably a roll temperature of room temperature (5 to 35° C.), a pressure of 1 to 50 N/cm ² and a time of 0.1 second to 5 minutes, more preferably 5 to 20 N/cm. cm ² , and the time is 1 second to 1 minute, but can be appropriately adjusted depending on the thickness and type of the material to be transferred. If the pressure is less than 1 N/cm ² , the conductive pattern may not be uniformly transferred to the transferred material, and if it exceeds 50 N/cm ² , the transfer substrate may become difficult to separate.

When the bonded transfer base material and transfer material are separated, the angle measured according to JIS Z0237 on the transfer material side at the time of separation is preferably shallow. When the material to be transferred is peeled off from the transfer base material, a bend occurs at the peeled portion, which also bends the conductive pattern. It is preferable because the decrease is small. Specifically, it is preferable to peel off at 90 degrees or less. If it exceeds 90 degrees, depending on the thickness of the conductive pattern, the conductivity may decrease by several tens of percent.

In the present invention, the adhesive strength of a transfer material that is adhesive at room temperature is measured at a peeling angle of 180 degrees according to JIS Z0237, and is expressed as the adhesive strength per width of 25 mm (N/25 mm). In the present invention, the adhesive strength of the transferred material having adhesiveness at room temperature is preferably 0.1 to 20 N/25 mm, more preferably 0.2 to 10 N/25 mm. If the adhesive strength is less than 0.1 N/25 mm, the conductive pattern may not be transferred, and if it exceeds 20 N/25 mm, peeling of the transfer substrate may be difficult. Accordingly, in the present invention, having no adhesiveness means that the adhesive strength is less than 0.1 N/25 mm.

In the present invention, the material to be transferred is heat-cured after transferring the conductive pattern. By performing heat curing, the adhesion of the conductive pattern to the transferred material is improved, and the tackiness of the transferred material before the conductive pattern is transferred disappears or decreases. When a prepreg is used as a transfer target, the prepreg to which the conductive pattern has been transferred may be heated and cured as it is to form a conductive member. After that, it may be cured by heating to form a conductive member. Heat curing may be performed at a temperature and a heating time suitable for the thermosetting resin. For example, in the case of epoxy resin, the temperature is preferably 130 to 200° C., more preferably 140 to 190° C., and the heating time is 5 minutes. Although it is about 2 hours, it is not limited to this.

EXAMPLES The present invention will be described in detail below with reference to examples, but the content of the present invention is not limited to the examples.

(Example 1)
In water, diallyldimethylammonium chloride having chloride ions as counter ions, Sharoll (registered trademark) DC902P (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 8 parts by mass as a polymer, and vapor-phase silica (average primary particles) as inorganic fine particles 100 parts by mass of a powder having a diameter of 7 nm and a specific surface area of 300 m ² /g) was added, and a pre-dispersion liquid was prepared using a sawtooth blade type disperser (blade peripheral speed of 30 m/sec). Next, the resulting preliminary dispersion was treated with a high-pressure homogenizer to produce an inorganic fine particle dispersion 1 having a solid content concentration of 20% by mass. The average secondary particle size of the fumed silica was 130 nm.

Using the inorganic fine particle dispersion liquid 1, a porous layer forming coating liquid 1 having the following composition was prepared. Porous layer-forming coating solution 1 was applied to a 100 μm thick polyethylene terephthalate film (manufactured by Teijin DuPont Films Co., Ltd.) which had been treated for easy adhesion as a support, using a slide bead coater to give a solid content of 25 g/gas-phase silica equivalent. A porous layer was formed by coating and drying to a thickness of m ² . The thickness of the porous layer was 38 μm.

<Porous layer forming coating liquid 1>
Inorganic fine particle dispersion liquid 1 (as silica solid content) 100 parts by mass Polyvinyl alcohol 25 parts by mass (degree of saponification 88%, average degree of polymerization 3500)
Boric acid 4 parts by mass Nonionic surfactant 0.3 parts by mass (polyoxyethylene alkyl ether)
It was adjusted with water so that the concentration of components other than water was 13% by mass.

Next, the surface of the porous layer was coated with a coating liquid for an electroconductivity enhancer having the following composition by a coating method using a diagonal gravure roll, followed by drying with a drier. The oblique line gravure roll used here had a diameter of 60 mm, an oblique line angle of 45 degrees, a line number of 90 lines/inch, and a groove depth of 110 μm, and was used in reverse rotation. The moisture coating amount was set to 20 g/m ² by adjusting the number of rotations of the hatched gravure roll. The applied electroconductivity enhancer coating liquid was absorbed inside the porous layer, and the porous layer was exposed on the surface.

<Conductivity enhancer coating solution>
Sodium chloride 0.3 parts by mass Water 99.7 parts by mass

Next, a release layer coating solution 1 having the following composition was applied to the surface of the porous layer by a coating method using a diagonal gravure roll, and dried with a dryer to obtain a transfer base material 1. The oblique line gravure roll used here had a diameter of 60 mm, an oblique line angle of 45 degrees, a line number of 90 lines/inch, and a groove depth of 110 μm, and was used in reverse rotation. The moisture coating amount was set to 20 g/m ² by adjusting the number of rotations of the hatched gravure roll. The solid content coating amount of the release layer formed on the porous layer was 0.6 g/m ² .

<Release layer coating liquid 1>
Colloidal silica 20% by mass slurry 15 parts by mass (Fuso Chemical Industry Co., Ltd., Quatron PL-3L, average primary particle size 35 nm)
Water 85 parts by mass

<Preparation of conductive pattern on transfer substrate 1>
Using a piezo-type inkjet printer containing silver nano ink (NBSIJ-MU01 manufactured by Mitsubishi Paper Mills, Ltd., silver concentration 15% by mass), a solid pattern (planar pattern) of 50 mm × 50 mm was applied to the transfer substrate 1. Printing was performed to form a conductive pattern. The ejection amount of silver nanoink was 23 ml/m ² and the thickness of the conductive pattern was 0.8 μm.

Using a roll laminator, the conductive pattern forming surface of the transfer base material 1 and the prepreg (Torayca (registered trademark) F6343B manufactured by Toray Industries, Inc.) for molding the carbon fiber reinforced resin that is the transfer target 1, the thermosetting resin is epoxy The adhesive strength measured at a peel angle of 180 degrees according to JIS Z0237 at 25 ° C. is 0.25 N / 25 mm), the roll temperature is 25 ° C., the pressure is 10 N / cm ² , the speed is 0.3 m / min (as crimping time 1 second). After the press-bonding treatment, the transfer base material 1 was peeled off, and heat curing treatment was performed at 140° C. for 30 minutes to obtain a conductive member of Example 1 having a conductive pattern.

(Example 2)
2.5 parts by mass of nitric acid and 100 parts by mass of alumina hydrate (average primary particle size: 15 nm) are added to water, and inorganic fine particle dispersion 2 having a solid content concentration of 30% by mass is prepared using a sawtooth blade type disperser. got The average secondary particle size of the alumina hydrate dispersed in the inorganic fine particle dispersion liquid 2 was 160 nm.

Using the inorganic fine particle dispersion 2, a porous layer forming coating liquid 2 having the following composition was prepared. Forming Coating Liquid 2 was coated with a slide bead coater so that the solid content coating amount was 32 g/m ² in terms of alumina hydrate, and dried to form a porous layer. The film thickness of the porous layer was 42 μm.

<Porous layer forming coating liquid 2>
Inorganic fine particle dispersion liquid 2 (as alumina hydrate solid content) 100 parts by mass Polyvinyl alcohol 9 parts by mass (degree of saponification 88%, average degree of polymerization 3,500, molecular weight about 150,000)
Boric acid 0.4 parts by mass Nonionic surfactant 0.3 parts by mass (polyoxyethylene alkyl ether)
It was adjusted with water so that the concentration of components other than water was 16% by mass.

Next, the coating liquid of the electroconductivity enhancer having the composition shown above was applied to the surface of the porous layer by a coating method using a slanted gravure roll, and dried with a drier. The oblique line gravure roll used here had a diameter of 60 mm, an oblique line angle of 45 degrees, a line number of 90 lines/inch, and a groove depth of 110 μm, and was used in reverse rotation. The moisture coating amount was set to 20 g/m ² by adjusting the number of rotations of the hatched gravure roll. The applied electroconductivity enhancer coating liquid was absorbed inside the porous layer, and the porous layer was exposed on the surface.

Next, a release layer coating solution 2 having the following composition was applied to the surface of the porous layer by a coating method using a diagonal gravure roll, and dried with a dryer to obtain a transfer base material 2 . The oblique line gravure roll used here had a diameter of 60 mm, an oblique line angle of 45 degrees, a line number of 90 lines/inch, and a groove depth of 110 μm, and was used in reverse rotation. The moisture coating amount was set to 20 g/m ² by adjusting the number of rotations of the hatched gravure roll. The solid content coating amount of the release layer formed on the porous layer was 0.4 g/m ² .

<Dissociation layer coating solution 2>
Colloidal silica 40% by mass slurry 5 parts by mass (manufactured by Nissan Chemical Industries, Ltd., Snowtex ZL, average primary particle size 80 nm)
Water 95 parts by mass

A piezo-type inkjet printer containing silver nano ink (NBSIJ-MU01 manufactured by Mitsubishi Paper Mills, Ltd., silver concentration 15% by mass) is used on the transfer base material 2, and a solid pattern of 50 mm × 50 mm is printed. form a sexual pattern. The ejection amount of silver nanoink was 23 ml/m ² and the thickness of the conductive pattern was 0.8 μm.

Using a roll laminator, the conductive pattern forming surface of the transfer substrate 2 and the epoxy resin sheet (Sanyu Rec Co., Ltd. DRS-028, thermosetting resin is epoxy resin, JIS Z0237 at 25 ° C. The adhesive strength measured at a peeling angle of 180 degrees was 0.9 N/25 mm), and the pressure was applied at a roll temperature of 25°C, a pressure of 10 N/cm ² , and a speed of 0.3 m/min (1 second as the pressure bonding time). rice field. After the press-bonding treatment, the transfer base material 2 was peeled off, and heat curing treatment was performed at 150° C. for 60 minutes to obtain a conductive member of Example 2 having a conductive pattern.

(Example 3)
A conductive member of Example 3 was obtained in the same manner as in Example 2 except that the release layer coating solution 2 of Example 2 was changed to release layer coating solution 3 having the following composition. The solid content coating amount of the release layer formed on the porous layer was 0.6 g/m ² .

<Release layer coating liquid 3>
15 parts by mass of 20% by mass zirconium oxide sol (Zr100/20, manufactured by Nyacol, average primary particle size 100 nm)
Water 85 parts by mass

(Example 4)
A conductive member of Example 4 was obtained in the same manner as in Example 3 except that the transferee 2 in Example 3 was changed to the transferee 1 and the heat curing treatment was performed at 140° C. for 30 minutes.

(Example 5)
A conductive member of Example 5 was obtained in the same manner as in Example 2 except that the release layer coating solution 2 of Example 2 was changed to release layer coating solution 4 having the following composition. The solid content coating amount of the release layer formed on the porous layer was 0.2 g/m ² .

<Release layer coating solution 4>
1.7 parts by mass of fluororesin 60% by mass aqueous dispersion (PTFE D-210C manufactured by Daikin Industries, Ltd., average primary particle size 220 nm)
Water 98.2 parts by mass Anionic surfactant 0.05 parts by mass (sodium polyoxyethylene lauryl ether sulfate)

(Example 6)
A conductive member of Example 6 was obtained in the same manner as in Example 5, except that the transferee 2 in Example 5 was changed to the transferee 1 and the heat curing treatment was performed at 140° C. for 30 minutes.

(Comparative example 1)
The material to be transferred 1 used in Example 1 was subjected to a heat curing treatment at 140° C. for 30 minutes to form a non-adhesive sheet-like molding at room temperature. Dotite FA-333 manufactured by Co., Ltd.) was printed in a solid pattern of 50 mm×50 mm, and a silver paste heat curing treatment was performed at 120° C. for 10 minutes to obtain a conductive member of Comparative Example 1.

(Comparative example 2)
The material to be transferred 2 used in Example 2 was subjected to a heat curing treatment at 150° C. for 60 minutes to form a non-adhesive sheet-like molding at room temperature. Dotite FA-333 manufactured by Co., Ltd.) was printed in a solid pattern of 50 mm×50 mm, and a silver paste heat curing treatment was performed at 120° C. for 10 minutes to obtain a conductive member of Comparative Example 2.

(Comparative Example 3)
The material to be transferred 1 used in Example 1 was subjected to a heat curing treatment at 140° C. for 30 minutes to form a non-adhesive sheet-like molding at room temperature, and then produced on the transfer substrate 1 in Example 1. After transferring the conductive pattern to one side of a double-sided tape (Nitto Denko Co., Ltd. No. 5600, adhesive strength measured at a peeling angle of 180 degrees according to JIS Z0237 at 25 ° C. is 7.5 N / 25 mm) A conductive member of Comparative Example 3 was obtained by sticking the adhesive surface of the double-faced tape to which the conductive pattern was transferred to the transfer target 1 without the conductive pattern.

(Comparative Example 4)
The material to be transferred 2 used in Example 2 is subjected to a heat curing treatment at 150° C. for 60 minutes to form a non-adhesive sheet-like molding at normal temperature, and then produced on the transfer substrate 2 in Example 2. After transferring the conductive pattern onto one side of a double-sided tape (No. 5600 manufactured by Nitto Denko Co., Ltd.), the adhesive surface of the double-sided tape to which the conductive pattern has been transferred, which does not have the conductive pattern, is transferred. Affixed to the body 2, a conductive member of Comparative Example 4 was obtained.

The conductive members obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were evaluated as follows.
<Conductivity>
The sheet resistance value of the planar pattern transferred onto the conductive member was measured using a measuring device (Loresta (registered trademark)-GP manufactured by Dia Instruments Co., Ltd.). Table 1 shows the results.

<Adhesion>
Adhesion of the planar pattern transferred onto the conductive member to the transferred material was confirmed by the cross-cut method specified in JIS K 5600-5-6. Adhesion was evaluated on a scale of 0 to 5 in the same manner as in JIS K 5600-5-6. (0: No peeling in any grid mesh. 1: The degree of peeling is 5% or less. 2: The degree of peeling is more than 5% and 15% or less. 3: The degree of peeling is 15%. Table 1 shows the results.

From the results in Table 1, it can be seen that the method for producing a conductive member according to the present invention can provide a method for producing a conductive member with simple steps and good adhesion of the pattern.

REFERENCE SIGNS LIST 1 Support 2 Porous layer 3 Dissociation layer 4 Conductive pattern 5 Material to be transferred 10 Substrate for transfer

Claims (1)

A conductive pattern is formed on the release layer of a transfer substrate having at least a porous layer on a support and a release layer containing zirconium oxide as inorganic fine particles or fluororesin as organic fine particles on the porous layer. A conductive member comprising at least the steps of: transferring the conductive pattern obtained in the above step to a transfer-receiving material having adhesiveness at room temperature; and heating and curing the transfer-receiving material to which the conductive pattern has been transferred. Production method.

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