JP7439401B2 - contactless media - Google Patents

Description

The present invention relates to non-contact media loaded with conductive circuits and IC chips.

Formation of thin films or patterning of conductive circuits for electronic components such as conductive circuits and non-contact media loaded with IC chips or for electromagnetic shielding is generally done using thermosetting or thermoplastic conductive ink. Alternatively, a method of printing a circuit pattern and sintering it by heat treatment, or a method of etching a copper-clad base material is known.

As an example of the sintering method, JP-A No. 2000-305260 describes a photosensitive conductive paste consisting of an alkali-soluble negative photosensitive resin composition, a photopolymerization initiator, metal powder, and metal ultrafine particles. Paste is disclosed. In this publication, after patterning a photosensitive resin composition, organic components are volatilized in a firing furnace such as an electric furnace or a belt furnace, and an inorganic powder is fired to form a conductive pattern film. The firing atmosphere is air, nitrogen atmosphere, or hydrogen atmosphere at a temperature of 500° C. or higher, and requires large-scale equipment. However, the sintering method is difficult to apply to flexible packaging materials such as films and paper due to the high sintering temperature.

The etching method involves chemically or electrochemically dissolving and removing the surface or shape of metal, and using it as a processing technology in a broad sense that includes surface treatment. Etching is a type of chemical processing and is mainly performed to obtain a desired pattern shape on metal surfaces, but it is generally a complicated process and requires waste liquid treatment in the post-process, which poses problems. many. Further, since the conductive circuit formed by the etching method is formed only of metal such as aluminum or copper, there is a problem that it is vulnerable to physical impact such as bending.

The printing method using conductive ink can be expected to reduce the size and weight of electronic components, improve productivity, and reduce costs, and can easily impart conductivity by printing or coating on a base material and drying it. Demand for this printing method using conductive ink has been rapidly increasing in recent years because it can be performed at low temperatures during the drying and curing steps without applying high temperatures to the base material or electronic components.

As a specific example, in order to realize a ubiquitous society, the practical application of IC tags and RFID tags is being considered in various fields, and conductive technology is being used as a means to manufacture large quantities of IC tags and RFID tags in a short period of time. Formation of antenna circuits by printing with synthetic ink is being put into practical use. However, in order to function properly as an antenna, a circuit printed with ink with good conductivity is required, but circuits using conductive ink that use metal fillers such as silver or copper are common, which reduces material costs. As a result, its uses are limited. For example, in Japanese Unexamined Patent Publication No. 2007-197558, an RFID tag is manufactured using conductive ink using silver powder. On the other hand, various studies have been conducted on conductive ink that uses inexpensive conductive carbon instead of metal, but it is easy to imagine that it would be difficult to apply it to RFID tags due to insufficient conductivity. Ru.

Japanese Patent Application Publication No. 2000-305260 Japanese Patent Application Publication No. 2007-197558

An object of the present invention is to set the mixing ratio of a binder resin and a carbon material in a conductive composition used for forming a conductive circuit, and the mixing ratio of graphite and carbon other than graphite as carbon materials to a certain range, and to apply the mixture to a base material. The purpose of the present invention is to provide a contactless medium with excellent communication performance at low cost by forming a conductive circuit with uniquely excellent adhesion and conductivity.

That is, the present invention is a non-contact medium loaded with a conductive circuit and an IC chip,
The conductive circuit is a conductive circuit formed using a conductive composition containing a binder resin (A) and a carbon material (B),
The carbon material (B) includes graphite (B-1) and a carbon material other than graphite (B-2),
The solid content of the binder resin (A) and the mass ratio of the carbon material (B) are 15:85 to 35:65,
The present invention relates to a non-contact media characterized in that the content of graphite (B-1) is 70 to 99% by mass based on 100% by mass of carbon material (B).

The present invention relates to the above-mentioned non-contact type media, wherein the content of graphite (B-1) is 80 to 99% by mass based on 100% by mass of the carbon material (B).

The present invention relates to the non-contact type media described above, wherein the content of graphite (B-1) is 90 to 97.5% by mass based on 100% by mass of the carbon material (B).

The present invention relates to the non-contact type media described above, characterized in that the mass ratio of the solid content of the binder resin (A) to the carbon material (B) is 20:80 to 30:70.

The present invention relates to the non-contact media described above, wherein the carbon material (B-2) other than graphite contains carbon black.

The mixing ratio of the binder resin and carbon material in the conductive composition used to form the conductive circuit, and the mixing ratio of graphite and carbon other than graphite as the carbon material are set within a certain range, and the adhesion to the base material and conductivity are determined. By forming a conductive circuit with uniquely superior properties, it is possible to provide contactless media with excellent communication performance at low cost.

<Contactless media>
The non-contact medium (non-contact information recording medium) of the present invention is a non-contact medium loaded with a conductive circuit and an IC chip, and the conductive circuit is made of a binder resin (A) and a carbon material (B). It is characterized in that it is formed using a conductive composition containing.

<Conductive composition>
The conductive composition used in the non-contact media of the present invention contains a binder resin (A), a carbon material (B), and, if necessary, a solvent.

Further, the appropriate viscosity of the conductive composition depends on the method of applying the conductive composition, but is generally preferably 10 mPa·s or more and 30,000 mPa·s or less.

First, the binder resin (A) will be explained.

Binder resins include polyurethane, polyamide, acrylonitrile, acrylic, butadiene, polyvinyl butyral, polyolefin, polyester, polystyrene, EVA (ethylene-vinyl acetate copolymer), epoxy, and polyvinylidene fluoride. The resin may contain one or more selected from the group consisting of silicone-based resins, silicone-based resins, and the like. Particularly preferred are polyurethane, polyamide, and polyester. However, it is not limited to these resins. One type of binder resin may be used alone, or two or more types may be used in combination.
The binder resin can also be a curable resin that undergoes a curing (crosslinking) reaction after the binder resin is applied to the substrate.
In other words, the binder resin should be self-curing or in combination with a curing agent described below, and the conductive composition should be printed or coated on the base material and then cured (crosslinked). You can also do it.

As the binder resin, polyurethane resin is preferable from the viewpoint of volume resistivity, adhesion to the base material, and durability. After printing or coating a conductive composition on a base material, when (hot) pressing it, the resin softens and almost maintains the planar pattern shape of the conductive circuit at the time of printing and coating. On the other hand, when it flows in the thickness direction, it is possible to reduce voids and increase contact between the conductive carbon materials (B), so it is expected that the volume resistivity of the resulting conductive circuit will be reduced. Therefore, the binder resin is preferably one that softens and flows appropriately during (hot) pressing.

<Polyurethane resin>
The method for synthesizing the polyurethane resin is not particularly limited, but examples include reacting a polyol compound (a) with a diisocyanate (b), or reacting a polyol compound (a) with a diisocyanate (b) with a diol compound having a carboxyl group (c). to obtain a urethane prepolymer (d) having an isocyanate group, or further react the urethane prepolymer (d) with a polyamino compound (e), or in the above three cases, react as necessary. Examples include those obtained by reacting with a terminator.

As the polyol compound (a), various polyether polyols, polyester polyols, polycarbonate polyols, polybutadiene glycols, or mixtures thereof, which are generally known as polyol components constituting polyurethane resins, can be used.

Examples of polyether polyols include polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, and the like.
Examples of polyester polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1, Saturated and unsaturated low molecular diols such as 5-pentanediol, hexanediol, octanediol, 1,4-butylene diol, diethylene glycol, triethylene glycol, dipropylene glycol, dimer diol, and n-butyl glycidyl ether, 2 - Alkyl glycidyl ethers of ethylhexyl glycidyl ethers, monocarboxylic acid glycidyl esters such as versatic acid glycidyl ester, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, Polyester polyols obtained by dehydration condensation of dicarboxylic acids such as malonic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid, or their anhydrides, and ring-opening polymerization of cyclic ester compounds. Examples include the polyester polyols obtained.
As the polycarbonate polyols, 1) a reaction product of a diol or bisphenol with a carbonate ester, and 2) a reaction product of a diol or bisphenol with phosgene in the presence of an alkali can be used. Examples of carbonate esters include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, propylene carbonate, and the like. In addition, the diols include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 3,3 '-dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9 -nonanediol, neopentyl glycol, octanediol, butylethylpentanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, 3,9-bis(1,1-dimethyl-2-hydroxyethyl, 2,2 ,8,10-tetraoxospiro [5.5]
Examples include undecane. Examples of bisphenols include bisphenol A, bisphenol F, and bisphenols obtained by adding alkylene oxides such as ethylene oxide and propylene oxide to bisphenols.

The number average molecular weight (Mn) of the above-mentioned polyol compound is appropriately determined in consideration of the solubility of the polyurethane resin when producing the conductive composition, the durability of the conductive circuit to be formed, the adhesive strength to the base material, etc. However, the range is usually preferably from 580 to 8,000, more preferably from 1,000 to 5,000.
The above polyol compounds may be used alone or in combination of two or more. Furthermore, a part of the above polyol compound can be replaced with low molecular diols, such as various low molecular diols used in the production of the above polyol compound, within a range where the performance of the polyurethane resin is not lost.

As the diisocyanate compound (b), aromatic diisocyanates, aliphatic diisocyanates, alicyclic isocyanates, or mixtures thereof can be used, and isophorone diisocyanate is particularly preferred. Aromatic diisocyanates include 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-benzylisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1 , 3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate and the like.

Examples of the aliphatic diisocyanate include butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and the like.
Examples of the alicyclic diisocyanate include cyclohexane-1,4-diisocyanate, isophorone diisocyanate, norbornane diisocyanatomethyl, bis(4-isocyanatecyclohexyl)methane, 1,3-bis(isocyanatemethyl)cyclohexane, methylcyclohexane diisocyanate, etc. It will be done.

Examples of the diol compound (c) having a carboxyl group include dimethylol alkanoic acids such as dimethylol acetic acid, dimethylol propionic acid, dimethylol butanoic acid, and dimethylol pentanoic acid, dihydroxysuccinic acid, and dihydroxybenzoic acid. Particularly preferred are dimethylolpropionic acid and dimethylolbutanoic acid from the viewpoint of reactivity and solubility.
The conditions for reacting the polyol compound (a), the diisocyanate (b), and the diol compound (c) having a carboxyl group to obtain the urethane prepolymer (d) having an isocyanate group include, in addition to making the isocyanate group excessive. Although there is no particular limitation, it is preferable that the isocyanate group/hydroxyl group equivalent ratio is within the range of 1.05/1 to 3/1. More preferably, it is 1.2/1 to 2/1. Further, the reaction is usually carried out between room temperature and 150°C, and preferably between 60 and 120°C from the viewpoint of production time and control of side reactions.

The polyamino compound (e) acts as a chain extender, and includes ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, norbornanediamine, and 2 -(2-Aminoethylamino)ethanol, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxypropylethylenediamine and other hydroxyl group-containing amines may also be used. can. Among them, isophoronediamine is preferably used.

When synthesizing a polyurethane resin by reacting a urethane prepolymer (d) having an isocyanate group with a polyamino compound (e), a reaction terminator can be used in combination to adjust the molecular weight of the resulting polyurethane resin. As the reaction terminator, dialkylamines such as di-n-butylamine, dialkanolamines such as diethanolamine, and alcohols such as ethanol and isopropyl alcohol can be used.

The conditions for reacting the urethane prepolymer (d) having an isocyanate group with the polyamino compound (e) and, if necessary, a reaction terminator are not particularly limited; When the group is taken as 1 equivalent, the total equivalent of the amino groups in the polyamino compound (e) and the reaction terminator is preferably within the range of 0.5 to 1.3. More preferably, it is within the range of 0.8 to 0.995.
The weight average molecular weight of the polyurethane resin is preferably in the range of 5,000 to 200,000 from the viewpoint of coatability and handleability.

When synthesizing polyurethane resin, one or two types selected from ester solvents, ketone solvents, glycol ether solvents, aliphatic solvents, aromatic solvents, alcohol solvents, carbonate solvents, water, etc. are used. The above can be used in combination.
Examples of the ester solvent include ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate, and ethyl lactate.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, diisobutyl ketone, diacetone alcohol, isophorone, and cyclohexanone.
Glycol ether solvents include ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, and acetate esters of these monoethers, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and propylene. Examples include glycol monomethyl ether, propylene glycol monoethyl ether, and acetate esters of these monoethers.
Examples of aliphatic solvents include n-heptane, n-hexane, cyclohexane, methylcyclohexane, and ethylcyclohexane.
Examples of aromatic solvents include toluene and xylene.
Examples of alcoholic solvents include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, cyclohexanol, and the like.
Examples of carbonate solvents include dimethyl carbonate, ethylmethyl carbonate, di-n-butyl carbonate, and the like.

<Polyamide resin>
As the binder resin, polyamide resin is preferable from the viewpoint of volume resistivity and adhesion to the base material. Good volume resistivity results are obtained because the resin component during (hot) pressing is easy to flow.
The polyamide resin used in the present invention is basically a general term for polymers with amide bonds obtained through various reactions such as polycondensation of dibasic acids and diamines, polycondensation of aminocarboxylic acids, or ring-opening polymerization of lactams. In addition to various modified polyamides, products manufactured using partially hydrogenated reactants, products partially copolymerized with other monomers, or products mixed with other substances such as various additives. It is a broad concept that includes things.

The polyamide resin used in the present invention is not particularly limited as long as the above conditions are met, but a dimer acid-modified polyamide resin obtained by condensation polymerization of a dibasic acid whose main component is a dimer acid and a polyamine is preferred. . Dimer acid When producing dimer acid-modified polyamide resin, dimer acid obtained by polymerizing natural monobasic unsaturated fatty acids contained in tall oil fatty acids, soybean oil fatty acids, etc. is widely used industrially. The dicarboxylic acids may include various dicarboxylic acids such as saturated aliphatic, unsaturated aliphatic, alicyclic, or aromatic.
Commercially available products of the dimer acid include Haridimer 200 and 300 (manufactured by Harima Kasei Co., Ltd.), Versadime 228 and 216, and Enpol 1018, 1019, 1061, and 1062 (manufactured by Cognis Co., Ltd.). Furthermore, hydrogenated dimer acids can also be used, and examples of commercially available hydrogenated dimer acids include Pripol 1009 (manufactured by Croda Japan Co., Ltd.) and Enpol 1008 (manufactured by Cognis Corporation).
In addition to the dimer acids mentioned above, various dicarboxylic acids can be used as dibasic acids in order to make polyamide resins with appropriate flexibility. Specifically, dicarboxylic acids include oxalic acid, malonic acid, succinic acid (anhydride), maleic acid (anhydride), glutaric acid, adipic acid, bimelic acid, suberic acid, azelaic acid, sebacic acid, terephthalic acid, and isophthalic acid. Acids such as phthalic acid, naphthalene dicarboxylic acid, 1,3- or 1,4-cyclohexanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, and the like are used.

Furthermore, dibasic acids having a phenolic hydroxyl group can also be used. By using a dibasic acid having a phenolic hydroxyl group, the phenolic hydroxyl group can be introduced into the side chain of the polyamide resin, and can be used for reaction with a curing agent.
As a dibasic acid having a phenolic hydroxyl group,
Hydroxyisophthalic acids such as 2-hydroxyisophthalic acid, 4-hydroxyisophthalic acid, 5-hydroxyisophthalic acid,
Dihydroxyisophthalic acid such as 2,5-dihydroxyisophthalic acid, 2,4-dihydroxyisophthalic acid, 4,6-dihydroxyisophthalic acid,
dihydroxyterephthalic acid such as 2-hydroxyterephthalic acid, 2,3-dihydroxyterephthalic acid, 2,6-dihydroxyterephthalic acid,
Hydroxyphthalic acids such as 4-hydroxyphthalic acid and 3-hydroxyphthalic acid,
Examples include dihydroxyphthalic acids such as 3,4-dihydroxyphthalic acid, 3,5-dihydroxyphthalic acid, 4,5-dihydroxyphthalic acid, and 3,6-dihydroxyphthalic acid.
Further, examples thereof include acid anhydrides and ester derivatives such as polybasic acid methyl ester.
Among these, 5-hydroxyisophthalic acid is preferred in terms of copolymerizability, ease of availability, and the like.

Furthermore, various monocarboxylic acids are used as necessary in order to make the polyamide resin have appropriate fluidity when heated. As the monocarboxylic acid, specifically, propionic acid, acetic acid, caprylic acid (octanoic acid), stearic acid, oleic acid, etc. are used.
Examples of polyamines used as reactants in producing the dimer acid-modified polyamide resin include various diamines such as aliphatic, alicyclic, and aromatic diamines, triamines, and polyamines. Specific examples of the above diamine include ethylenediamine, propanediamine, butanediamine, triethylenediamine, tetraethylenediamine, hexamethylenediamine, p- or m-xylenediamine, 4,4'-methylenebis(cyclohexylamine), 2,2-bis -(4-cyclohexylamine), polyglycol diamine, isophorone diamine, 1,2-, 1,3- or 1,4-cyclohexane diamine, 1,4-bis-(2'-aminoethyl)benzene, N-ethyl Examples include aminopiperazine and piperazine.
Further, triamines include diethylenetriamine, and polyamines include triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and the like. Furthermore, a dimer diamine obtained by converting a dimerized aliphatic nitrile group and reducing it with hydrogen can also be used.

Examples of polyamine compounds include compounds obtained by converting the carboxyl group of a polybasic acid compound having a cyclic or acyclic hydrocarbon group having 20 to 48 carbon atoms into an amino group, and examples of commercially available products include, for example, Croda Examples include "Priamine 1071", "Priamine 1073", "Priamine 1074", and "Priamine 1075" manufactured by Japan Corporation, and "Versamine 551" manufactured by Cognis Japan Corporation.
An alkanolamine may be used in combination with the diamine. Examples of alkanolamines include ethanolamine, propanolamine, diethanolamine, butanolamine, 2-amino-2-methyl-1-propanol, and 2-(2-aminoethoxy)ethanol. Moreover, polyether diamine having oxygen in its skeleton can be used. This polyether has the general formula H ₂ N-R ₁ -(RO) _n -R ₂ -NH ₂ (where n is 2 to 100, and R ₁ and R ₂ have 1 to 14 carbon atoms. An alkylene group or a divalent alicyclic hydrocarbon group, where R is an alkylene group or a divalent alicyclic hydrocarbon group having 1 to 10 carbon atoms.The alkylene group is a linear It can be represented by the following formula. Examples of the ether diamine include polyoxypropylene diamine, and commercially available products include Jeffamines (manufactured by Sun Techno Chemical Co., Ltd.). Mention may also be made of bis-(3-aminopropyl)-polytetrahydrofuran.
The above-mentioned polyamines and dimer acids or various dicarboxylic acids are thermally condensed by a conventional method, and various polyamide resins including dimer acid-modified polyamide resins are produced through an amidation step accompanied by dehydration. Generally, the reaction temperature is about 100 to 300°C and the reaction time is about 1 to 8 hours.

<Polyester resin>
As the binder resin, polyester resin is preferable from the viewpoint of volume resistivity and adhesion to the base material. Good volume resistivity results are obtained because the resin component during (hot) pressing is easy to flow.
Polyester resin is a polymer composed of polyhydric carboxylic acid and polyhydric alcohol as monomers. Any known polyester resin can be used, and specifically, from the viewpoint of ensuring the cohesive force of the resin, it is preferable that the weight average molecular weight is 1,000 to 100,000. Further, from the viewpoint of adhesion, it is preferable that the glass transition temperature is -10°C to 200°C.
Examples of the polycarboxylic acid component constituting the polyester resin include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, unsaturated dicarboxylic acids, trivalent or higher carboxylic acids, and one or two of these. You can select and use any of the above. On the other hand, examples of the polyhydric alcohol component constituting the polyester resin include aliphatic glycols, ether glycols, trihydric or higher polyalcohols, and one or more of these can be selected and used.
Commercial products of polyester resin include Vylon (manufactured by Toyobo Co., Ltd., "Vylon" is a registered trademark), Polyester (manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd., "Polyester" is a registered trademark), and Teslac (manufactured by Hitachi Chemical Polymer Co., Ltd.). , ``Teslac'' is a registered trademark), etc.

Next, the carbon material (B) will be explained.

The conductive carbon material (B) in the conductive composition of the present invention is characterized by containing graphite (B-1) and a carbon material other than graphite (B-2).
Further, the mass ratio of the binder resin (A) to the carbon material (B) is 15:85 to 35:65, preferably 20:80 to 30:70.

When the mass ratio of the binder resin is less than 15, the adhesion of the conductive circuit decreases, resulting in poor adhesion. On the other hand, if the mass ratio of the binder resin exceeds 35, contact between carbon materials in the conductive circuit is inhibited, resulting in poor conductivity.

When the mass ratio of the binder resin is 20 to 30, adhesion can be achieved without inhibiting the formation of a conductive network in a conductive circuit formed by the conductive composition.

As the graphite (B-1), for example, artificial graphite or natural graphite can be used. Artificial graphite is produced by heat-treating amorphous carbon to artificially orient irregularly arranged micrographite crystals, and is generally produced using petroleum coke or coal-based pitch coke as the main raw material. Ru. As the natural graphite, flaky graphite, lumpy graphite, earthy graphite, etc. can be used. In addition, expanded graphite (also referred to as expandable graphite) obtained by chemically treating flaky graphite, or expanded graphite obtained by heat treating expanded graphite and then micronizing or pressing may be used. I can do it. Among these graphites, flaky graphites such as flaky graphite, expanded graphite, and exfoliated graphite are preferred from the viewpoint of electrical conductivity when used in conductive circuits of wiring sheets.

The surface of these graphites may be subjected to surface treatments such as epoxy treatment, urethane treatment, silane coupling treatment, oxidation treatment, etc. in order to increase the affinity with the binder resin as long as the characteristics of the conductive composition of the present invention are not impaired. may be applied.

Further, the average particle size of the graphite used is preferably 2 to 100 μm, particularly preferably 20 to 50 μm.

If the average particle size of graphite is less than 2 μm, the aspect ratio of the graphite particles decreases and contact between graphite particles tends to become point contact, making it impossible to form a sufficient conductive network. On the other hand, when the average particle size of graphite is 100 μm or more, the voids between graphite particles become large, and the proportion of conductive paths formed between carbon materials other than graphite in the conductive network increases, causing a decrease in conductivity.

The average particle size in the present invention is the particle size (D50) at which 50% is obtained when the volume ratio of particles is integrated from the smallest particle size in the volume particle size distribution. The particle size distribution meter is measured using a particle size distribution meter such as a dynamic light scattering type particle size distribution meter ("Microtrack UPA" manufactured by Nikkiso Co., Ltd.).

Examples of commercially available graphite include CMX, CPB, UP-5, UP-10, UP-20, UP-35N, CSSP, CSPE, CSP, CP, and CB-150 manufactured by Nippon Graphite Industries Co., Ltd. as flaky graphite. , CB-100, ACP, ACP-1000, ACB-50, ACB-100, ACB-150, SP-10, SP-20, J-SP, SP-270, HOP, GR-15, LEP, F#1 , F#2, F#3, CX-3000, FBF, BF, CBR, SSC-3000, SSC-600, SSC-3, SSC, CX-600, CPF-8, CPF-3, manufactured by Chuetsu Graphite Co., Ltd. CPB-6S, CPB, 96E, 96L, 96L-3, 90L-3, CPC, S-87, K-3, CF-80, CF-48, CF-32, CP-150, CP-100, CP, HF-80, HF-48, HF-32, SC-120, SC-80, SC-60, SC-32, EC1500 manufactured by Ito Graphite Industries, EC1000, EC500, EC300, EC100, EC50, manufactured by Nishimura Graphite Co., Ltd. 10099M, PB-99, etc. Examples of the spherical natural graphite include CGC-20, CGC-50, CGB-20, and CGB-50 manufactured by Nippon Graphite Industries. Examples of the earthy graphite include Blue P, AP, AOP, and P#1 manufactured by Nippon Graphite Industries Co., Ltd., and APR, S-3, AP-6, and 300F manufactured by Chuetsu Graphite Co., Ltd. Examples of artificial graphite include PAG-60, PAG-80, PAG-120, PAG-5, HAG-10W, HAG-150 manufactured by Nippon Graphite Industries, and RA-3000, RA-15, RA- manufactured by Chuetsu Graphite Co., Ltd. 44, GX-600, G-6S, G-3, G-150, G-100, G-48, G-30, G-50, SGP-100, SGP-50, SGP-25 manufactured by SEC Carbon , SGP-15, SGP-5, SGP-1, SGO-100, SGO-50, SGO-25, SGO-15, SGO-5, SGO-1, SGX-100, SGX-50, SGX-25, SGX -15, SGX-5, and SGX-1. It is not limited to these, and two or more types may be used in combination.

Further, the content of graphite (B-1) in the conductive composition of the present invention is 70 to 99% by mass in 100% by mass of carbon material (B), and especially %, preferably 75 to 99% by mass, more preferably 80 to 99% by mass in 100% by mass of carbon material (B), and even more preferably 90 to 97% in 100% by mass of carbon material (B). It is preferably 5% by mass.

When the content of graphite (B-1) is less than 70% by mass in 100% by mass of carbon material (B), the excessive amount of carbon material (B-2) other than graphite may reduce the orientation of graphite particles. If carbon materials other than graphite occupy most of the conductive network, high conductivity will not be achieved. Furthermore, if the carbon material (B) is 75% by mass or more in 100% by mass, specific high conductivity is exhibited. On the other hand, when the content of graphite exceeds 99% by mass in 100% by mass of the carbon material (B), the conductivity in the planar direction due to the graphite particles becomes dominant, and the conductivity of the conductive circuit reaches a peak.

When the content of graphite (B-1) is 80% by mass or more based on 100% by mass of the carbon material (B), a good coating film can be formed with few pinholes in the conductive circuit.

When the content of graphite (B-1) is 90 to 97.5% by mass in 100% by mass of carbon material (B), in addition to high conductivity in the planar direction due to graphite particles, an appropriate amount of non-graphite The carbon material (B-2) strengthens the vertical conductive network without inhibiting the planar conductivity derived from graphite, and can exhibit extremely high conductivity.

When the content of graphite (B-1) is less than 90% by mass based on 100% by mass of carbon material (B), a coating film with less uneven conductive circuits can be obtained.

(Carbon materials other than graphite (B-2))
The carbon material other than graphite is not particularly limited, but carbon black is more preferable from the viewpoint of particle size and specific surface area. In addition, conductive carbon fibers (carbon nanotubes, carbon nanofibers, carbon fibers), fullerenes, etc. can be used alone or in combination of two or more types.

Carbon black is produced by continuously pyrolyzing gaseous or liquid raw materials in a reactor, especially Ketjen black made from ethylene heavy oil, which burns the raw material gas and uses the flame to pass through the bottom of the channel steel. Various types of black, such as channel black precipitated by quenching and precipitating, thermal black obtained by periodically repeating combustion and thermal decomposition using gas as a raw material, and acetylene black made from acetylene gas in particular, can be used alone or in combination. More than one type can be used in combination. Further, commonly used oxidized carbon black, hollow carbon, etc. can also be used.

Oxidation treatment of carbon is performed by treating carbon at high temperature in air or by secondary treatment with nitric acid, nitrogen dioxide, ozone, etc. This is a process in which oxygen-containing polar functional groups are directly introduced (covalently bonded) to the carbon surface, and is commonly performed to improve the dispersibility of carbon. However, it is common that the electrical conductivity of carbon decreases as the amount of functional groups introduced increases, so it is preferable to use carbon that has not been oxidized.

The larger the specific surface area of the carbon black used, the more contact points between carbon black particles, which is advantageous for lowering the volume resistivity. Specifically, the specific surface area (BET) determined from the amount of nitrogen adsorption is 20 m ² /g or more and 1500 m ² /g or less, preferably 50 m ² /g or more and 1500 m ² /g or less, and more preferably 100 m ² /g or more,
It is desirable to use one with a surface area of 1500 m ² /g or less. If carbon black with a specific surface area of less than 20 m ² /g is used, it may be difficult to obtain sufficient conductivity, and carbon black with a specific surface area of more than 1500 m ² /g may be difficult to obtain as a commercially available material. be.

Further, the particle size of the carbon black used is preferably 0.005 to 1 μm in terms of primary particle size, particularly preferably 0.01 to 0.2 μm. However, the primary particle diameter here is the average of particle diameters measured using an electron microscope or the like.

Commercially available carbon blacks include, for example, Toka Black #4300, #4400, #4500, #5500 manufactured by Tokai Carbon, Printex L manufactured by Degussa, Raven 7000, 5750, 5250, 5000 ULTRA III, 500 manufactured by Columbian.
0ULTRA, ConductexSCULTRA, Conductex975ULTRA, PUERBLACK100, 115, 205, Mitsubishi Chemical #2350, #2400B, #2600B, #3050B, #3030B, #3230B, #3350B, #3400B , #5400B, MONARCH1400 manufactured by Cabot, 1300, 900, Vulcan Denki Kagaku Kogyosha Examples include acetylene blacks such as Denka Black, Denka Black HS-100, and FX-35 manufactured by Kogyo Co., Ltd., but the invention is not limited to these, and two or more types may be used in combination.

The conductive carbon fibers are preferably those obtained by firing from petroleum-derived raw materials, but those obtained by firing from plant-derived raw materials can also be used. Furthermore, carbon nanotubes include single-walled carbon nanotubes in which a single layer of graphene sheets forms a tube having a diameter in the nanometer range, and multi-walled carbon nanotubes in which multiple graphene sheets are formed. Therefore, the diameter of multi-walled carbon nanotubes is as large as 30 nm, compared to 0.7-2.0 nm for typical single-walled carbon nanotubes.

Commercially available conductive carbon fibers and carbon nanotubes include vapor grown carbon fibers such as VGCF manufactured by Showa Denko Co., Ltd., and EC1.0, EC1.5, EC2.0, EC1.5-P manufactured by Meijo Nano Carbon Co., Ltd. single-walled carbon nanotubes, FloTube9000, FloTube9100, FloTube9110, FloTube9200 manufactured by CNano, NC7000 manufactured by Nanocyl, 100T manufactured by Knano, and the like.

Next, the solvent will be explained. When uniformly mixing the binder resin (A) and the conductive carbon material (B) in the conductive composition, a solvent can be used as appropriate. Examples of such solvents include organic solvents and water.
Organic solvents include alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol methyl ether, diethylene glycol methyl ether, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, etc. ethers, hydrocarbons such as hexane, heptane, and octane, aromatics such as benzene, toluene, xylene, and cumene, and esters such as ethyl acetate and butyl acetate, depending on the composition of the conductive composition. things can be used. Further, two or more kinds of solvents may be used.
In addition, when employing a printing coating method such as screen printing which requires the conductive composition to have a viscosity above a certain level, the viscosity of the organic solvent at 25° C. is preferably 30 mPa·s to 75000 mPa·s. If it is less than 30 mPa・s, high conductivity is exhibited, and the resin content is low, so good dispersibility of the viscous and conductive carbon material suitable for coating cannot be obtained, resulting in insufficient coating properties. If it exceeds 75,000 mPa·s, the viscosity is too high and the dispersibility of the carbon material is significantly reduced. Examples include terpineol, dihydroterpineol, 2,4-diethyl-1,5-pentanediol, 1,3-butylene glycol, and isobornylcyclohexanol. Two or more kinds of high viscosity solvents shown here may be used, and methyl ethyl ketone, toluene, and isopropyl alcohol have a viscosity of 30 mPa・s at 25°C.
It is also possible to use it in combination with a low viscosity solvent.

Next, other components will be explained. The conductive composition of the present invention may contain ultraviolet absorbers, ultraviolet stabilizers, radical scavengers, fillers, thixotropy agents, anti-aging agents, antioxidants, as necessary, to the extent that the effects of the present invention are not impaired. agent, antistatic agent, flame retardant, thermal conductivity improver, plasticizer, anti-sag agent, antifouling agent, preservative, bactericide, antifoaming agent, leveling agent, antiblocking agent, hardening agent, thickener, Various additives such as pigment dispersants and silane coupling agents may be added.

(Dispersing machine/mixing machine)
As the apparatus used to obtain the conductive composition, a dispersing machine and a mixer commonly used for dispersing pigments and the like can be used.

For example, mixers such as a disper, homomixer, or planetary mixer; homogenizers such as "Clearmix" manufactured by M Techniques or "Filmix" manufactured by PRIMIX; paint conditioner (manufactured by Red Devil), ball mill, and sand mill. (such as "Dyno Mill" manufactured by Shinmaru Enterprises), attritor, pearl mill (such as "DCP Mill" manufactured by Eirich Co., Ltd.), or media-type dispersion machines such as Koboru Mill; Wet jet mill ("Zinus PY" manufactured by Genus Corporation, Sugino Medialess dispersion machines such as "Starburst" manufactured by Machine Co., "Nanomizer" manufactured by Nanomizer Co., Ltd.), "Clair SS-5" manufactured by M Technique Co., Ltd., or "MICROS" manufactured by Nara Kikai Co., Ltd.; or other roll mills, etc. These include, but are not limited to.

For example, when using a media-type dispersion machine, the agitator and vessel are made of ceramic or resin, or the surface of the metal agitator and vessel is treated with tungsten carbide spraying or resin coating. It is preferable to use As the media, it is preferable to use glass beads, zirconia beads, or ceramic beads such as alumina beads. Only one type of dispersion device may be used, or a plurality of types of devices may be used in combination.

(conductive circuit)
The conductive circuit used in the non-contact media of the present invention is produced by printing the above-mentioned conductive composition on one or both sides of a base material such as paper or plastic by screen printing, rotary screen printing, or flexographic printing, depending on the intended use. The conductive circuit can be formed by printing using a conventional printing method such as gravure printing, gravure offset printing, offset printing, letterpress printing, or inkjet printing.

As the paper base material, coated paper, uncoated paper, and various other processed papers such as synthetic paper, polyethylene coated paper, impregnated paper, waterproof paper, insulation paper, and elastic paper can be used, but as non-contact media, In order to obtain a stable resistance value, coated paper and processed paper are preferable. In the case of coated paper, the higher the smoothness, the more preferable it is. Plastic base materials include polyester, polyethylene, polypropylene, cellophane, vinyl chloride, vinylidene chloride, polystyrene, vinyl alcohol, ethylene-vinyl alcohol, nylon, polyimide, polycarbonate, and other plastics used for ordinary tags and cards. The following substrates can be used.

By using the conductive ink of the present invention, a conductive circuit can be formed by a normal printing method, so it is possible to design using existing equipment. In other words, it is possible to print and form conductive circuits directly after performing normal printing to enhance the design of non-contact media such as pictures, which is an improvement over circuit formation that was conventionally done by etching or transfer methods. It is far superior in terms of productivity, initial investment cost, and running cost compared to the conventional method.
In a process before printing and forming the conductive circuit, an anchor coating agent or various varnishes may be applied to the base material for the purpose of increasing adhesion to the base material. Further, after printing the conductive circuit, overprint varnish, various coating agents, etc. may be applied for the purpose of protecting the circuit. As these various varnishes and coating agents, either ordinary heat drying type or active energy ray curing type can be used.

Alternatively, a non-contact medium can be obtained by applying an adhesive onto the conductive circuit and then laminating it with a paper base material or plastic film on which a pattern or the like is printed, or by melt extrusion of plastic. Of course, it is also possible to use a base material coated with a pressure-sensitive adhesive or adhesive in advance.

The conductor circuit manufactured by the above method is mounted on a base material together with an IC module to obtain a non-contact ID. The base material holds the conductive circuit and the IC chip, and can be made of paper, film, or the like similar to the base material of the conductive circuit. Furthermore, the IC chip is used to store, accumulate, and perform calculations on data. Contactless ID is an RFID (Radio Frequency Identification), contactless IC card, contactless IC tag, data carrier (recording medium), or wireless card that uses radio waves to identify an individual between it and a reader or reader/writer. It performs identification and sends and receives data. Its uses include ID management and history management in toll collection systems, etc., and location management in road usage management systems, freight and baggage tracking and management systems, etc.

(Volume resistivity of conductive circuit)
The conductive circuit of the present invention preferably has a volume resistivity of less than 5×10 ⁻² Ω·cm. If the volume resistivity is less than 5×10 ⁻² Ω·cm, it can be suitably used as a non-contact type media. Note that the lower the volume resistivity is, the higher the conductivity is exhibited even in a thin film. Therefore, in consideration of material cost, productivity, and performance as a non-contact type media, the lower the volume resistivity is, the more preferable it is.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the following Examples do not limit the scope of the present invention in any way. In addition, "part" in Examples and Comparative Examples represents "part by mass", Mw means weight average molecular weight, and Tg means glass transition temperature.

<Synthesis of binder resin A-1>
A polyester polyol obtained from terephthalic acid, adipic acid, and 3-methyl-1,5-pentanediol (manufactured by Kuraray Co., Ltd.) was placed in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube. 455.5 parts of "Kuraray Polyol P-2011" (Mn=2011), 16.5 parts of dimethylolbutanoic acid, 105.2 parts of isophorone diisocyanate, and 140 parts of toluene were reacted at 90°C for 3 hours under a nitrogen atmosphere. 360 parts of toluene was added to obtain a urethane prepolymer solution having isocyanate groups. Next, 19.9 parts of isophoronediamine, 0.63 parts of di-n-butylamine, 294.5 parts of 2-propanol, and 335.5 parts of toluene were mixed with the obtained urethane prepolymer solution having isocyanate groups. 969.5 parts were added, reacted at 50°C for 3 hours and then 70°C for 2 hours, diluted with 126 parts of toluene and 54 parts of 2-propanol, Mw = 61,000, acid value = 10mgKOH/g, urethane pre- A solution of polyurethane resin A-1 was obtained in which the total equivalent weight of the amino groups in the polyamino compound and the reaction terminator was 0.98 with respect to the free isocyanate groups at both ends of the polymer.

<Synthesis of binder resin A-2>
In a 4-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, inlet tube, and thermometer, 156.2 g of Pripol 1009 as a polybasic acid compound, 5.5 g of 5-hydroxyisophthalic acid, and Priamine as a polyamine compound were added. 146.4 g of 1074 and 100 g of ion-exchanged water were charged, and the mixture was stirred until the exothermic temperature became constant. Once the temperature stabilized, the temperature was raised to 110°C, and after confirming the outflow of water, the temperature was raised to 120°C after 30 minutes, and then the dehydration reaction was continued while increasing the temperature by 10°C every 30 minutes. . When the temperature reached 230° C., the reaction was continued at that temperature for 3 hours, maintained under a vacuum of about 2 kPa for 1 hour, and then the temperature was lowered. Finally, an antioxidant was added to obtain polyamide resin A-2 having a weight average molecular weight of 24,000, an acid value of 13.2 mgKOH/g, a hydroxyl value of 5.5 mgKOH/g, and a glass transition temperature of -32°C.

The resin was evaluated as follows.
<Method for measuring weight average molecular weight (Mw)>
Mw was measured using GPC (gel permeation chromatography) "HPC-8020" manufactured by Tosoh Corporation. GPC is liquid chromatography that separates and quantifies substances dissolved in a solvent (THF; tetrahydrofuran) based on the difference in molecular size. The measurement in the present invention uses two "LF-604" columns (manufactured by Showa Denko Co., Ltd.: GPC column for rapid analysis: 6 mm ID x 150 mm size) connected in series, a flow rate of 0.6 ml/min, and a column temperature. It was carried out at 40° C., and the weight average molecular weight (Mw) was determined in terms of polystyrene.
<Measurement of acid value>
Approximately 1 g of the sample was accurately weighed into a stoppered Erlenmeyer flask, and 100 ml of a toluene/ethanol (volume ratio: toluene/ethanol = 2/1) mixture was added to dissolve it. Add phenolphthalein test solution to this as an indicator and hold for 30 seconds. Thereafter, it is titrated with 0.1N alcoholic potassium hydroxide solution until the solution takes on a pale pink color. The acid value was determined by the following formula (unit: mgKOH/g). Acid value (mgKOH/g) = (5.611 x a x F)/S
however,
S: Amount of sample collected (g)
a: Consumption amount (ml) of 0.1N alcoholic potassium hydroxide solution
F: Potency of 0.1N alcoholic potassium hydroxide solution <Method for measuring hydroxyl value>
The hydroxyl value is the amount of hydroxyl groups contained in 1 g of hydroxyl group-containing resin expressed as the amount of potassium hydroxide (mg) required to neutralize acetic acid bonded to the hydroxyl groups when the hydroxyl groups are acetylated. It is. The hydroxyl value was measured according to JIS K0070. In the present invention, when calculating the hydroxyl value, the acid value is taken into consideration as shown in the following formula.
<Measurement of hydroxyl value>
Approximately 1 g of the sample was accurately weighed into a stoppered Erlenmeyer flask, and 100 ml of a toluene/ethanol (volume ratio: toluene/ethanol = 2/1) mixture was added to dissolve it. Furthermore, exactly 5 ml of an acetylating agent (a solution of 25 g of acetic anhydride dissolved in pyridine to a volume of 100 ml) was added, and the mixture was stirred for about 1 hour. To this, phenolphthalein test solution is added as an indicator and maintained for 30 seconds. Thereafter, it is titrated with 0.1N alcoholic potassium hydroxide solution until the solution takes on a pale pink color.
The hydroxyl value was determined by the following formula (unit: mgKOH/g).
Hydroxyl value (mgKOH/g) = [{(ba) x F x 28.05}/S] + D
however,
S: Amount of sample collected (g)
a: Consumption amount (ml) of 0.1N alcoholic potassium hydroxide solution
b: Consumption amount (ml) of 0.1N alcoholic potassium hydroxide solution in blank experiment
F: Potency of 0.1N alcoholic potassium hydroxide solution D: Acid value (mgKOH/g)
<Method for measuring glass transition temperature>
Measurement was performed using a binder resin from which the solvent had been dried and heated at a rate of 2°C/min from -80 to 150°C using "DSC-1" manufactured by Mettler Toledo.

<Adjustment of binder resin>
The binder resin used in Examples and Comparative Examples was adjusted to a solution with a solid content of 20% using the solvent shown below. The composition ratio of the mixed solvent is expressed as a mass ratio.
- Solution of binder resin A-1-1: Dilute the solution of binder resin A-1 with toluene/methyl ethyl ketone/2-propanol (1/1/1 (mass ratio)) to make a solution of binder resin A-1-1. I got it.
- Solution of binder resin A-2-1: Binder resin A-2 was diluted with toluene/2-propanol (2/1) to obtain a solution of binder resin A-2-1.
- Solution of binder resin A-3-1: Binder resin A-3: Vylon 200 (manufactured by Toyobo Co., Ltd., polyester resin) was diluted with toluene/methyl ethyl ketone (1/1 (mass ratio)) to make binder resin A-3. -1 solution was obtained.

<Conductive composition and conductive circuit>
(Example 1)
120 parts of solution of A-1-1 as binder resin (resin solid content 24 parts), B-1-1 as conductive carbon material: 70 parts of scaly graphite CB-150 (manufactured by Nippon Graphite Co., Ltd.), other than graphite B-2-1: 6 parts of Furnace Black #3050 (manufactured by Mitsubishi Chemical Corporation) as a carbon material and 204 parts of toluene/methyl ethyl ketone/2-propanol (1/1/1) as a solvent were mixed in a mixer. The mixture was then placed in a sand mill for dispersion to obtain a conductive composition (1).
Using the obtained conductive composition, a circuit was produced by the following method, and the conductive circuit and non-contact media were evaluated. The results are shown in Table 1.

(Volume resistivity of conductive circuit)
The conductive composition (1) was applied onto a 125 μm thick PEN (polyethylene naphthalate) film using a doctor blade, and then heated and dried. The dry film thickness was adjusted to 5 μm, and a conductive circuit (10 cm×10 cm coating film) for evaluating volume resistivity was obtained.
The volume resistivity of the conductive circuit was determined by measuring with a four-terminal method (JIS-K7194) using Loresta GP (manufactured by Mitsubishi Chemical Analytech). The evaluation results are shown in Table 1.
◎: “Volume resistivity is less than 5×10 ⁻³ Ω・cm (extremely good)”
○: “Volume resistivity is 5×10 ⁻³ Ω・cm or more and less than 1×10 ⁻² Ω・cm (good)”
○△: “Volume resistivity is 1×10 ⁻² Ω・cm or more and less than 5×10 ⁻² Ω・cm (usable)”
△: “Volume resistivity is 5×10 ⁻² Ω・cm or more and less than 1×10 ⁻¹ Ω・cm (defective)”
×: “Volume resistivity is 1×10 ⁻¹ Ω・cm or more (extremely poor)”

(Adhesion of conductive circuit)
The conductive composition (1) was applied onto a 125 μm thick PEN film using a doctor blade, and then dried by heating. The dry film thickness was adjusted to 5 μm, and a conductive circuit (10 cm×10 cm coating film) for evaluation of adhesion was obtained.
In the conductive circuit produced above, six cross-cut cuts were made vertically and horizontally at intervals of 2 mm from the surface of the conductive circuit to a depth reaching the base material using a knife. Adhesive tape was attached to this cut and immediately peeled off, and the extent to which the conductive circuit had fallen off was visually determined. The evaluation results are shown in Table 1, and the evaluation criteria are shown below.
○: “No peeling (level with no practical problems)”
○△: “Slight peeling (problems, but usable level)”
△: “About half peeled off”
×: “Peeling off in most parts”

<Evaluation of coatability of conductive circuit>
The conductive composition (1) was applied onto a 125 μm thick PEN film using a doctor blade, and then dried by heating. The dry film thickness was adjusted to 5 μm, and a conductive circuit (10 cm x 10 cm coating film) for coating property evaluation was obtained.

It was evaluated by the coating property evaluation shown below. The conductive circuit was visually observed, and coating unevenness (unevenness: evaluated by the shade of the painted surface) and pinholes (evaluated by the presence or absence of defects where the conductive circuit was not applied) were judged according to the following criteria. The evaluation results are shown in Table 1.
(village)
○: No shading in the conductive circuit is observed (good).
Δ: There are 1 to 3 shading areas in the conductive circuit, but these are extremely small areas (no problem in practice).
×: Shading in the conductive circuit was confirmed in 4 or more places, or one or more pieces had a length of shading stripes of 5 mm or more (defective).
(pinhole)
○: Not a single pinhole was observed (good).
Δ: There are 1 to 3 pinholes, but they are extremely small (no practical problem).
×: 4 or more pinholes were confirmed, or 1 or more pinholes with a diameter of 1 mm or more (extremely poor).

(Non-contact media characteristics of conductive circuit)
A flexographic plate (DSF plate: manufactured by DuPont) having a conductive pattern was attached to the second unit of a CI type 6 color flexographic printing machine SOLOFLEX (manufactured by Windmoeller & Hoelscher KG), and a flexographic plate (DSF plate: manufactured by DuPont) with a conductive pattern was printed on a PEN film (125 μm) at a speed of 70 m/min. The conductive composition (1) was sequentially printed at high speed. The film thickness of the printed matter was measured with a digital micro film thickness meter (MH15M manufactured by Nikon Corporation), the printing conditions were adjusted appropriately so that the average film thickness was 5 to 10 μm, and after drying by heating, A conductive circuit was obtained. An I C chip manufactured by Impinge was mounted on the obtained conductive circuit to create a non-contact type media.
Next, we used Impinge's ``Fixed UHF band RFID reader/writer Speedway Revolution R420'' to confirm whether communication was possible.
〇: Readable ×: Not readable

(Example 2 to Example 41, Comparative Example 1 to Comparative Example 12)
Conductive compositions (2) to (41) and (a) to (l) were obtained using the composition ratios shown in Table 1 and in the same manner as for conductive composition (1).
In Examples 16 and 27, since the type of binder resin was different from Example 1, toluene/2-propanol (2/1) was used as the dilution solvent when preparing the conductive composition.
In Examples 17 and 28, since the type of binder resin was different from that in Example 1, toluene/methyl ethyl ketone (1/1) was used as the dilution solvent when preparing the conductive composition.

The materials used in the examples are shown below.
<Binder resin (A)>
・A-1: Polyurethane resin ・A-2: Polyamide resin ・A-3: Polyester resin Vylon 200 (manufactured by Toyobo Co., Ltd.)
<Carbon material (B)>
<Graphite (B-1)>
・B-1-1: Scale graphite CB-150 (manufactured by Nippon Graphite Co., Ltd.) average particle size 40 μm (catalog)
・B-1-2: Scale graphite CPB (manufactured by Nippon Graphite Co., Ltd.) average particle size 20 μm (catalog)
・B-1-3: Scale graphite FB-100 (manufactured by Nippon Graphite Co., Ltd.) average particle size 80 μm (catalog)
・B-1-4: Exfoliated graphite CMX (manufactured by Nippon Graphite Co., Ltd.) average particle size 40 μm (catalog)
・B-1-5: Spheroidal graphite CGB-50 (manufactured by Nippon Graphite Co., Ltd.) average particle size 50 μm (catalog)
・B-1-6: Expanded graphite LEP (manufactured by Nippon Graphite Co., Ltd.) average particle size 100 μm (catalog)
・B-1-7: Artificial graphite PAG-5 (manufactured by Nippon Graphite Co., Ltd.) average particle size 50 μm (catalog)
<Carbon materials other than graphite (B-2)>
・B-2-1: Furnace black #3050B (manufactured by Mitsubishi Chemical Corporation)
・B-2-2: Denka Black HS-100 (manufactured by Denki Kagaku Kogyo Co., Ltd.)
・B-2-3: Ketjen Black EC-300J (manufactured by Lion Specialty Chemicals)
・B-2-4: Carbon nanotube VGCF (manufactured by Showa Denko)
・B-2-5: Ketjen Black EC-600JD (manufactured by Lion Specialty Chemicals)

In Examples 1 to 41, communication could be confirmed because the resistance value of the conductive circuit was low. On the other hand, communication could not be confirmed in Comparative Examples 3, 4, 5, 6, 8, 9, 11, and 12 because the resistance values were high. In addition, in Comparative Examples 1, 2, 7, and 10, the amount of conductive particles filled was large and the resistance value was low, so transmission and reception were possible, but on the other hand, the resin content was small and the adhesion to the base material was extremely poor. , its practicality as a contactless media is poor.

Claims (5)

A contactless media loaded with a conductive circuit and an IC chip,
The conductive circuit is a conductive circuit formed using a conductive composition containing a binder resin (A) and a carbon material (B),
The carbon material (B) includes graphite (B-1) (excluding expanded graphite) and a carbon material other than graphite (B-2),
The solid content of the binder resin (A) and the mass ratio of the carbon material (B) are 15:85 to 35:65,
The content of graphite (B-1) is 70 to 99% by mass in 100% by mass of carbon material (B), and the binder resin (A) contains polyurethane resin, polyamide resin, or polyester resin. contactless media.
The non-contact media according to claim 1, wherein the content of graphite (B-1) is 80 to 99% by mass based on 100% by mass of the carbon material (B). The non-contact media according to claim 1 or 2, wherein the content of graphite (B-1) is 90 to 97.5% by mass based on 100% by mass of the carbon material (B). The non-contact type according to any one of claims 1 to 3, characterized in that the mass ratio of the solid content of the binder resin (A) to the carbon material (B) is 20:80 to 30:70. media. The non-contact media according to any one of claims 1 to 4, wherein the carbon material (B-2) other than graphite contains carbon black.