JP7012284B2 - Manufacturing method of conductive cloth and conductive cloth - Google Patents

Description

The present invention relates to a method for manufacturing a conductive cloth having a conductive pattern (circuit) or the like on the cloth, and a conductive cloth.

The conductive fabric can be used as a wearable device by mounting electronic components and sensors. By wearing a wearable device using such a conductive cloth, it is possible to measure biological signals and movements of humans and animals, which are used in the medical and healthcare fields, as well as in the environment and construction fields. Its usefulness is attracting attention in various industries such as.

Conventional techniques for imparting conductivity to fabric include a method of weaving or knitting conductive threads (for example, Patent Document 1), or a paste paint containing a conductive material such as a conductive polymer. Examples thereof include a method of applying (for example, Patent Document 2).

In addition, a method of forming a thin metal layer on a cloth via an adhesive layer or a protective resin layer for decorative purposes has been proposed (for example, Patent Documents 3 and 4). Further, there has been proposed an electronic garment in which the gaps between threads on the cloth surface are filled and solidified with an adhesive resin to form an electronic circuit or the like by an inkjet printing method (for example, Patent Document 5).

Japanese Unexamined Patent Publication No. 2013-019064 Japanese Unexamined Patent Publication No. 2014-151018 Japanese Patent Application Laid-Open No. 2003-073982 Japanese Unexamined Patent Publication No. 07-216765 Japanese Unexamined Patent Publication No. 2005-146499

However, the method of weaving or knitting a conductive thread has problems that a special device is required, the cost is high, and the degree of freedom of the conductive pattern shape is low. In addition, in the method of simply applying the paste paint containing the conductive material, the coating amount inevitably increases and the thickness of the conductive pattern portion of the fabric increases in order to avoid insufficient conductivity. There is a problem that it tends to be hard and heavy. Along with this, the formed conductive pattern portion cannot follow the flexibility of the fabric, and the pattern portion is broken or the like, which causes a problem that the conductivity is impaired.

Further, such a conductive paste paint usually contains an adhesive (also referred to as a binder resin) such as an acrylic resin for ensuring fixing to the cloth. When a conductive paste layer containing an adhesive is used in the conductive pattern portion, or when a conductive paste containing a binder resin is used, impurities such as a resin other than a pure conductive substance are contained in the conductive pattern (circuit) portion on the fabric. It ends up. For this reason as well, the conductive pattern portion of the conductive fabric after production tends to be heavy. If the weight of the pattern portion becomes too heavy, the air permeability, which is important for practical use as a conductive fabric, will be significantly inferior to that of the original fabric.

The present invention has been made in view of the above circumstances, and is a method for manufacturing a conductive cloth having a light weight per unit area of a metal conductive pattern formed on the cloth and having sufficient conductivity, and a conductive cloth. The purpose is to provide.

In order to achieve the above object, the method for producing a conductive fabric according to the first aspect of the present invention is:
(I) A step of preparing a fabric having a fabric surface roughness (height difference of unevenness on the surface of the fabric) of at least one side of the fabric of 30 μm or more and 100 μm or less.
The step of cation-treating a range including a predetermined portion within at least a part of the range.
(Ii) After the cation treatment step , the average particle size (arithmetic mean value of the sphere-equivalent particle size of 100 particles measured by a transmission electron microscope) is determined at a predetermined location within at least a part of the range. The process of applying a dispersion of metal nanoparticles of 200 nm or less, and
(Iii) At least including a step of calcining the predetermined portion coated with the dispersion liquid to form a metal conductive pattern of 1 to 100 g / m ² .
The surface resistance value of the metal conductive pattern is 50 Ω / □ or less.

Prior to the step (i), a pretreatment step of smoothing by compression of the cloth is further included, and the pretreatment step further includes a cloth surface roughness (the unevenness of the cloth surface) of at least a part of at least one side of the cloth. A fabric having a height difference of 100 μm or less may be prepared.

Preferably, in the step (ii), the coating is applied by inkjet printing.

In order to achieve the above object, the conductive fabric according to the second aspect of the present invention is
A fabric having a fabric surface roughness (difference in height of unevenness on the surface of the fabric) of at least one side of the fabric of 30 μm or more and 100 μm or less.
It comprises at least a metal conductive pattern of 1 to 100 g / m ² arranged at a predetermined position within at least a part of the range.
The surface resistance value of the metal conductive pattern is 50 Ω / □ or less, and is
A cationic surfactant is applied to a range of the fabric including a predetermined portion within the range of at least a part thereof .

Preferably, the metal purity of the metal conductive pattern is 95% or more.

Preferably, the range in which the fabric surface roughness (height difference of the unevenness of the fabric surface) in the fabric is 100 μm or less is the air permeability of 0.1 to 20 cm ³ / cm ² / s.

According to the present invention, there is provided a method for manufacturing a conductive cloth having a light weight per unit area of a metal conductive pattern formed on the cloth and having sufficient conductivity, and a conductive cloth.

It is a perspective view which shows an example of the schematic structure of the conductive cloth which concerns on embodiment of this invention. It is a schematic block diagram which shows a part of the cross section of the line AA shown in FIG. It is a flowchart which shows the manufacturing process of the conductive cloth of Example 1. FIG. It is a figure which shows the outline of each manufacturing process of the conductive cloth of Example 1. FIG. It is a figure which shows the air permeability measurement result of the cloth which concerns on Example and the comparative example.

Hereinafter, the method for producing a conductive fabric according to the embodiment of the present invention and the conductive fabric produced by the method will be described in detail. In addition, in this specification, the expression "having", "preparing", "including" or "containing" also includes the meaning of "consisting of" or "consisting of".

<Manufacturing method of conductive fabric>
In the method for producing a conductive cloth according to the embodiment of the present invention, (i) a cloth having a cloth surface roughness (height difference of unevenness on the cloth surface) of at least a part of at least one side of the cloth is 100 μm or less is prepared. Steps, (ii) Metal nanoparticles having an average particle size (arithmetic mean value of sphere-equivalent particle size of 100 particles measured by a transmission electron microscope) of 200 nm or less at a predetermined location within at least a part of the range. It includes at least a step of applying a dispersion liquid of particles and (iii) at least a step of calcining the predetermined portion to which the dispersion liquid is applied to form a metal conductive pattern of 1 to 100 g / m ² . The surface resistance value of the formed metal conductive pattern is 50 Ω / □ or less. Hereinafter, each step will be described in detail.

(I) Preparation of cloth First, a cloth having a cloth surface roughness of at least a part of at least one side of the cloth having a roughness of 100 μm or less is prepared.

Here, the "fabric surface roughness" means the height difference of the unevenness of the fabric surface of the fabric, and specifically, the fabric (base material) is vertical (90 °) / horizontal (0 °) / diagonal ( 45 °) It means the height difference of the result measured in all directions by scanning the direction. Such a fabric surface roughness can be measured by a commercially available surface roughness measuring machine, a surface testing machine, or the like, and for example, "SV-3000CNC" (trade name, manufactured by Mitutoyo Co., Ltd.). Examples thereof include, but are not limited to, "SV-M3000CNC" (trade name, manufactured by Mitutoyo Co., Ltd.) and "KES-FB2-A" (trade name, manufactured by Kato Tech Co., Ltd.). In the present specification, the surface roughness measuring machine of "SV-3000CNC" (trade name, manufactured by Mitutoyo Co., Ltd.) is used to measure the cloth in the vertical (90 °) / horizontal (0 °) / diagonal (45 °) direction by 10 mm. The value of the height difference measured by scanning with a stroke is defined as "fabric surface roughness" (height difference of unevenness on the fabric surface).

Specific examples of the fabric include fiber fabrics such as woven fabrics, knitted fabrics, and non-woven fabrics. Examples of the fiber material include natural fibers such as cotton, linen, wool and silk, recycled fibers such as rayon and cupra, semi-synthetic fibers such as acetate and triacetate, polyamide (nylon 6, nylon 66, etc.) and polyester (polyethylene terephthalate). , Polytrimethylene terephthalate, etc.), polyurethane, polyacrylic, aramid, poly (paraphenylene benzobisoxazole), glass, synthetic fibers such as basalt, etc., but are not limited thereto. Two or more of these may be combined. Of these, a fabric made of synthetic fibers having excellent overall fiber characteristics is preferable. In particular, a cloth made of polyester fiber is preferable.

The fiber fabric may be dyed, antistatic processed and / or flame-retardant processed, if necessary. The processing applied to the fiber fabric referred to here is not a processing that substantially changes the surface roughness of the original fabric (excluding smoothing by compression in an additional pretreatment step described later). Moreover, if the processing does not impair the weight reduction of the metal conductive pattern, which is one of the effects of the present invention, processing on any fiber cloth or the surface of the fiber cloth known in the art may be included. For example, adhesive layer coating processing using a general adhesive resin is not included due to its weight, but on the other hand, the fabric is made into an inkjet fabric having high color development, disaster prevention, and / or durability. Ultra-thin resin coating processing for the purpose may be included. The thickness of the fabric itself is not particularly limited, but is preferably about 0.02 to 1 mm.

At least a part of at least one side of the fabric specifically includes at least a place (hereinafter, also referred to as a predetermined place) to which the dispersion liquid of the metal nanoparticles is applied in the step (ii) described later. It means the part of the range. Therefore, it may be a portion covering the entire one side (front surface or back surface) of the fabric, or a portion covering the entire both sides (front surface and back surface) of the fabric.

The fabric surface roughness of at least a part of the fabric desired in the embodiment of the present invention is 100 μm or less (0 to 100 μm), preferably 80 μm or less (0 to 80 μm), and more preferably 60 μm or less. It is (0 to 60 μm), more preferably 50 μm or less (0 to 50 μm). As long as it is on the surface of a smooth fabric that satisfies the numerical value of the surface roughness of the fabric, it is sufficient to have high metal purity and no disconnection after the steps (ii) and (iii) described later. A metal conductive pattern having conductivity can be produced. When the surface roughness of the fabric is larger than 100 μm, even if the metal conductive pattern is formed through the same process, the wire breaks due to the height difference of the unevenness, which is one of the effects exhibited by the present invention. The result is that conductivity cannot be obtained (see Examples of Evaluation of Surface Resistance Value (Conductivity) in Relation to Fabric Surface Roughness of Fabric, which will be described later).

When a fabric whose surface roughness does not meet the above-mentioned numerical conditions is used depending on the original yarn type or woven structure of the fabric, as an additional pretreatment step, on both sides, one side or at least a part of one side of the fabric. Smoothing by compression may be performed. As the method of smoothing by compression, any method known in the art may be used. Examples thereof include, but are not limited to, calender processing and / or compression processing using a thermal roller, a steel roller and / or an elastic roller, and thermal compression processing using a flat heat press machine or the like.

The range in which the fabric surface roughness (height difference of the unevenness of the fabric surface) in the fabric is 100 μm or less is preferably 0.1 to 20 cm ³ / cm ² / s air permeability. When the fabric surface roughness is 100 μm or less over the entire one side or both sides of the fabric as described above, the air permeability in the range of the entire fabric may satisfy the numerical condition. When the air permeability of the fabric is remarkably high, it is generally considered that the cloth surface roughness (the height difference of the unevenness of the cloth surface) is also remarkably large. It may be possible that the conductivity of the fabric cannot be ensured. Therefore, by applying the fabric having the characteristics of air permeability under the numerical conditions as the fabric of the method according to the embodiment of the present invention, the weight per unit area of the metal conductive pattern is light for the conductive fabric produced. However, the effect of the present invention of having sufficient conductivity can be more reliably exhibited. The numerical condition of 0.1 to 20 cm ³ / cm ² / s is sufficient breathability in practical use of the cloth when used as a conductive cloth (breathability in relation to the cloth surface roughness of the cloth described later). (See Examples for Evaluation). Since the conductive fabric produced by the method according to the embodiment of the present invention does not contain an adhesive layer or a binder resin in the pattern portion, it also has an effect that the original air permeability characteristics of the fabric can be easily maintained. Have. Therefore, it is more preferable to apply this manufacturing method to a fabric having as good a breathability as possible in consideration of the numerical condition of the surface roughness of the fabric related to ensuring the conductivity.

The fabric having the characteristics of air permeability under the numerical conditions can be obtained by looking at specific examples of the above-mentioned fabric types, and also by considering the above-mentioned additional smoothing pretreatment step as necessary. A person skilled in the art can easily make an appropriate selection. The air permeability of the fabric can be measured using a commercially available measuring machine. In the present specification, specifically, the measured value of the air permeability is measured by using "FX3300" (trade name, manufactured by TEXTEST INSTRUMENTS) at a test pressure of 125 Pa (JIS L 1096-A standard). It is defined as "air permeability".

(Ii) Application of dispersion liquid of metal nanoparticles Next, in the cloth prepared in (i) above, the average particle size is 200 nm at a predetermined place within the range of the portion where the cloth surface roughness is 100 μm or less. The following dispersion of metal nanoparticles is applied.

The predetermined portion means a portion of the conductive fabric to be manufactured in which a metal conductive pattern is desired to be formed. Depending on the shape and type of the desired metal conductive pattern, the dispersion liquid may be applied over the entire range of the portion where the fabric surface roughness of the fabric is 100 μm or less.

As used herein, the dispersion liquid of metal nanoparticles (also referred to as metal nanoparticle ink, metal nanoink or metal nanopaste) means a solution in which metal nanoparticles are appropriately dispersed in a solvent. The dispersion liquid of the metal nanoparticles contains, for example, the metal nanoparticles, a dispersant (dispersion protective agent), and a solvent. Since the metal nanoparticles tend to aggregate, in many cases, the surface of the metal nanoparticles is coated with a dispersant to suppress the aggregation and stabilize the particles. In this case, the dispersant desorbs from the metal nanoparticles as the solvent evaporates in an arbitrary drying step after application (for example, printing) of the dispersion liquid or in the step (iii) described later, and gives a conductive pattern. It will be. As the dispersion liquid of such metal nanoparticles, one prepared by any method known in the art can be used.

The solvent is not particularly limited as long as it can stably disperse the metal nanoparticles coated with the dispersant, and any solvent known in the art may be appropriately selected and used. For example, water, alcohol-based solvent (monoalcohol-based solvent, diol-based solvent, polyhydric alcohol-based solvent, etc.), hydrocarbon-based solvent, ketone-based solvent, ester-based solvent, ether-based solvent, glyme-based solvent, halogen-based solvent, etc. However, it is not limited to these. These solvents may be used alone or in combination of two or more. Of these, an alcohol solvent is preferable. Examples of the alcohol solvent include terpineol, ethylene glycol, ethanol, butanol, carbitol, isopropyl alcohol, 1-hexanol, 1,3-butanediol, 1-pentanol, 4-methyl-2-pentanol and the like. Examples of the hydrocarbon solvent include decalin, bicyclohexyl, dodecane, tetradecane, xylene, trimethylbenzene, ethylbenzene, propylbenzene, butylbenzene, pentylbenzene, methylethylbenzene, tetrahydronaphthalene and the like, and examples of the ester solvent include Examples thereof include propylene glycol monomethyl ether acetate and ethoxyethyl propionate. Examples of the ether solvent include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol tertiary butyl ether and dipropylene glycol monomethyl ether. , Ethylene glycol butyl ether, ethylene glycol ethyl ether, ethylene glycol methyl ether, diethylene glycol butyl ether, diethylene glycol ethyl ether and the like.

The dispersant is not particularly limited as long as it can ensure the dispersibility of the metal nanoparticles in the solvent, and any agent known in the art may be appropriately selected and used, preferably an amphipathic molecule. Is. Examples thereof include, but are not limited to, amine compounds and thiol compounds. The amine compound is preferably an aliphatic amine compound, and more preferably an aliphatic amine compound having an alkyl moiety having 4 to 10 carbon atoms. Examples of the aliphatic amine compound include alkylamines such as octylamine, dodecylamine and hexadecylamine, and alkenylamines such as oleylamine. The thiol compound is preferably an aliphatic thiol compound. Examples of aliphatic thiols include alkyl thiols such as hexane thiol, pentane dithiol, decane thiol and dodecane thiol. The dispersant may be used alone or in combination of two or more. By using a dispersant having a small number of carbon atoms, it can be desorbed or decomposed under easy conditions.

The metal nanoparticles generally mean metal nanoparticles having a particle size distribution in the nanometer region, but the average particle size of the metal nanoparticles desired in the embodiment of the present invention is 200 nm or less ( 1 to 200 nm), preferably 150 nm or less (1 to 150 nm), more preferably 100 nm or less (1 to 100 nm), still more preferably 50 nm or less (1 to 50 nm), and even more preferably 20 nm. The following (1 to 20 nm). The average particle size of the metal nanoparticles is the primary particle size that does not take into account aggregation, and is 100 or more actually measured using any method known in the art, for example, a transmission electron microscope (TEM). It can be expressed by the arithmetic average value of the sphere-equivalent particle size of particles (diameter when each particle is converted into spheres of the same volume). Specifically, the "average particle size of metal nanoparticles" in the present specification means the arithmetic mean value of the sphere-equivalent particle size of 100 particles measured by a transmission electron microscope. The average particle size of such metal nanoparticles is appropriately determined according to the method of applying the dispersion liquid described later (for example, a printing method), the desired shape of the metal conductive pattern and / or the firing method of the step (iii) described later. Can be selected and adjusted.

The metal nanoparticles are generally preferably spherical, but may have an amorphous shape close to spherical. Examples of the metal species of the metal nanoparticles include silver, gold, copper, platinum, palladium, rhodium, ruthenium, iridium, osmium, aluminum, indium, rubidium, cobalt, nickel, iron, tin and the like. Not limited. Of these, silver is preferred. These metal nanoparticles may be used alone or in combination of two or more.

The mixing ratio of the metal nanoparticles in the dispersion liquid of the metal nanoparticles is preferably about 0.1 to 70% by mass, 1 to 60% by mass, and 10 to 50% by mass with respect to the total mass of the dispersion liquid, which will be described later. It may be appropriately adjusted according to the method of applying the dispersion liquid (for example, the printing method), the desired shape of the metal conductive pattern and / or the firing method of the step (iii) described later. The same applies to the mixing ratios of the solvent and the dispersant in the dispersion liquid, and by adjusting these mixing ratios, it is possible to obtain a suitable viscosity according to various coating methods (for example, printing methods) of the dispersion liquid described later. can.

As the dispersion liquid of such metal nanoparticles, a commercially available metal nanoparticle ink, metal nanoink, metal nanopaste, or the like may be used as it is. For example, silver nanoparticles ink "NBSIJ-KC01" (product name, manufactured by Mitsubishi Paper Co., Ltd.), "NBSIJ-MU01" (product name, manufactured by Mitsubishi Paper Co., Ltd.), "KGK NANO AGK 101" (product name, Kishu Giken). (Product name, manufactured by Kishu Giken Kogyo Co., Ltd.), "KGK NANO AGK 102" (product name, manufactured by Kishu Giken Kogyo Co., Ltd.), "NAG-09" (product name, manufactured by Daiken Kagaku Kogyo Co., Ltd.), "NAG-09C11" (product name, manufactured by Daiken). "NPS-JL" (trade name, manufactured by Harima Kasei), "NPS-J" (trade name, manufactured by Harima Kasei), "NPS-J-HTB" (product), which is a silver nanopaste (manufactured by Chemical Industry Co., Ltd.) Name, manufactured by Harima Kasei Co., Ltd.), "NPG-J" (trade name, manufactured by Harima Kasei Co., Ltd.), which is a gold nanopaste, and the like, but are not limited thereto.

As an alternative to the metal nanoparticle ink, a dispersion liquid of a conductive carbon nanomaterial (also referred to as conductive carbon nanoink) may be used. The dispersion liquid of the conductive carbon nanomaterial is such that conductive carbon nanoparticles, conductive carbon nanotubes, conductive carbon nanorods, graphene and / or conductive carbon nanohorns are appropriately dispersed in a solvent as described above. Means a solution. The dispersion liquid of the conductive carbon nanomaterial contains, for example, the conductive carbon nanomaterial, the above-mentioned dispersant, and a solvent. The average diameter of the conductive carbon nanomaterial (average particle diameter (arithmetic mean value of sphere-equivalent particle diameter of 100 particles measured by a transmission electron microscope)) is 200 nm or less (1 to 200 nm), preferably 150 nm or less. It is (1 to 150 nm), more preferably 100 nm or less (1 to 100 nm), further preferably 50 nm or less (1 to 50 nm), and even more preferably 20 nm or less (1 to 20 nm).

In the production method according to the embodiment of the present invention, by using such a metal nanoparticle ink (or conductive carbon nanoink) having an average particle diameter of 200 nm or less, finally, the subsequent step (iii) is performed. It is possible to form a metal conductive pattern having conductivity in a weight per unit area of 1 to 100 g / m ² as described in the above.

As a method of applying the metal nanoparticle ink (or conductive carbon nanoink) to a predetermined place on the cloth, any method known in the art may be used. For example, inkjet printing, screen printing, gravure printing, zeroography, stamping, flexographic printing, offset printing, painting, air brushing and the like can be mentioned, but the present invention is not limited thereto. Various methods can be carried out by using each commercially available printing device or the like. Further, depending on various methods, a drying step of a solvent or the like after coating, for example, a warm air drying step may be included. Of these methods, inkjet printing is preferable. Conditions such as an appropriate ejection amount and resolution in inkjet printing can be determined by those skilled in the art, such as the composition of the metal nanoparticle ink (or conductive carbon nanoink), the desired shape of the metal conductive pattern, and / or (iii) described later. It may be possible to appropriately set according to the firing method and the like in the above process.

Preferably, before such a coating step, the range including the predetermined portion (the portion where the formation of the metal conductive pattern is desired) to be coated with the dispersion liquid in (ii) in the cloth prepared in (i) above. Is cation-treated in advance. The range to be treated with cations may include at least the predetermined portion of the fabric. Therefore, the cation treatment may be performed over the entire range of the portion where the fabric surface roughness of the fabric is 100 μm or less, and further, over one side (front surface or back surface) of the fabric, or over both sides (front surface and back surface) of the fabric. It may be treated with a cation.

The cationic treatment is a treatment of positively charging and stabilizing the target surface of the fabric by using a cationic surfactant or an aqueous solution thereof. Specific examples thereof include a treatment method in which the target surface of the fabric or the entire fabric is immersed in an aqueous solution of a cationic surfactant, squeezed with a mangle (roller), and dried by a general method such as warm air. It is not limited to this method. By performing the cation treatment in advance, the cationic surfactant reacts with the ink dispersant on the surface of the fabric, so that the metal nanoparticles are evenly dispersed and the adhesion of the particles is stabilized, so that bleeding occurs. It is possible to obtain sufficient conductivity with a smaller amount of ink applied. Cation treatment is an optional step, for example, if a fabric with a highly low surface roughness and smooth fabric is used and a suitable sufficient amount of metal nanoparticle ink is applied to such fabric, cation treatment. Sufficient conductivity can be ensured even if there is no ink.

As the cationic surfactant, any one known in the art may be appropriately selected and used. For example, dialkylbenzenealkylammonium chloride, lauryltrimethylammonium chloride, alkylbenzylmethylammonium chloride, alkylbenzyldimethylammonium bromide, benzalconium chloride, cetylpyridinium bromide, C12, C15, C17-trimethylammonium bromide, quaternized polyoxy. Examples thereof include, but are not limited to, a halide salt of ethylalkylamine, dodecylbenzyltriethylammonium chloride, or a mixture thereof.

(Iii) Firing Finally, at least the predetermined portion coated with the dispersion liquid in (ii) described above is calcined to form a metal conductive pattern (sintered film) of 1 to 100 g / m ² .

Considering the simplicity of the work, baking may be performed over the entire range of the portion where the fabric surface roughness of the fabric is 100 μm or less, more preferably over one side (front surface or back surface) of the fabric.

As the firing method, any firing method known in the art can be appropriately selected and used. Examples thereof include, but are not limited to, heating by a baking furnace (oven), infrared heating, various laser annealings, ultraviolet rays, visible light, light irradiation using flash light, microwave heating, and the like. Preferably, it is carried out under an inert gas atmosphere or a reducing gas atmosphere. When it is performed in an atmospheric atmosphere, heating is preferably performed instantaneously in order to prevent oxidation during firing.

Among these firing methods, either plasma firing, particularly a method of firing by surface wave plasma generated by application of microwave energy, or a method of firing by flash light irradiation is preferable. By using these firing methods, it is possible to reduce heat damage to the fabric and the like, and it is also possible to suppress oxidation of the metal during firing. In addition, since it can be fired for a short time, it has an advantage of high productivity.

Further, firing by light irradiation with a flash light source having a continuous wavelength spectrum from ultraviolet rays to infrared rays is more preferable, and specifically, light irradiation with a xenon flash light source is preferable. When such a light source is used, the same effect as that of UV irradiation at the same time as heating can be obtained, and firing can be performed in an extremely short time. When a xenon flash light source is used, by appropriately controlling the irradiation time and irradiation energy, it is possible to heat only the ink application location and its vicinity, and it is possible to suppress the influence of heat on the base material (fabric). .. Further, the number of irradiations and the irradiation interval can be appropriately adjusted according to the desired shape and type of the metal conductive pattern, the composition of the ink, and the like. As described above, even if the light irradiation with the xenon flash light source is performed in an extremely short time, the solvent and the dispersant in the coating ink are easily decomposed, volatilized or desorbed, and only the metal conductive pattern remains. It can be easily sintered.

The weight per unit area of the formed metal conductive pattern is 1 to 100 g / m ² , preferably 1 to 75 g / m ² , more preferably 1 to 50 g / m ² , and even more preferably 1. It is ~ 25 g / m ² , and even more preferably 1 to 10 g / m ² . Here, in the present specification, the "weight per unit area of the metal conductive pattern" or the "metal conductive pattern of ~ g / m ² " refers to the surface of the cloth using the method according to the embodiment of the present invention. When forming a metal conductive pattern on top, the weight of the entire fabric before and after forming the metal conductive pattern is defined as a value calculated from the difference in the amount of metal conductive pattern measured by "AUW220D" (trade name, manufactured by Shimadzu Corporation). do. Here, in the method according to the embodiment of the present invention, only the metal nanoparticle ink (or the conductive carbon nanoink) is applied on the surface of the fabric, so that the “metal conductive pattern” in the present specification is applied. It means a pattern formed by firing a metal nanoparticle ink (or conductive carbon nanoink), and contains almost no impurities such as a binder resin which can be normally contained. Therefore, the weight per unit area of the metal conductive pattern can be appropriately controlled and adjusted by those skilled in the art by changing the composition or coating conditions of the metal nanoparticle ink (or conductive carbon nanoink). be.

The surface resistance value of the metal conductive pattern thus formed is 50 Ω / □ or less, which is a value that can be considered effective for functioning as a conductive fabric. The surface resistance value of the metal conductive pattern is preferably 25 Ω / □ or less, more preferably 20 Ω / □ or less, still more preferably 10 Ω / □ or less, still more preferably 5 Ω / □ or less. Here, in the present specification, the "surface resistance value (of the metal conductive pattern)" means a value measured by "Lorester-EP MCP-T360" (trade name, manufactured by Mitsubishi Chemical Analytech Co., Ltd.). The lower limit of the surface resistance value is not particularly limited, but is preferably 0.0001Ω / □ or more.

The weight per unit area of 1 to 100 g / m ² for the metal conductive pattern is considerably lighter than the weight of the conductive pattern (circuit) formed on the surface of a general conductive cloth. While the weight of the metal conductive pattern according to the present invention is 1 to 100 g / m ² , for example, in the above-mentioned techniques such as Patent Documents 2 to 5, the conductive pattern portion includes an adhesive layer, a binder resin, or the like. Therefore, the thickness of the pattern combined with the metal portion is about 20 to 50 μm, and the weight of the conductive pattern is also as heavy as about 150 to 380 g / m ² . Regarding the manufacturing method according to the embodiment of the present invention, the structure in which the weight per unit area of the formed metal conductive pattern is light and does not contain an adhesive layer, a binder resin, or the like is a configuration in which the air permeability of the manufactured conductive fabric is low. It also leads to the effect that the original characteristics of the fabric are easily maintained.

In the conductive fabric produced by the method according to the embodiment of the present invention, although the formed metal conductive pattern has a weight per unit area of about 1 to 100 g / m ² , as described above. It has conductivity with a surface resistance value of 50Ω / □ or less. This is more specifically for the following reasons. In the production method according to the embodiment of the present invention, metal nanoparticles having an average particle diameter of 200 nm or less containing only a solvent, a dispersant and a metal component that are almost decomposed, volatilized or desorbed on the surface of the cloth dough after the firing step. Only particle ink is applied. Therefore, the content ratio of impurities in the sintered metal conductive pattern becomes low, the metal purity becomes about 95% or more, and the conductivity is maintained even if the weight per unit area is 1 to 100 g / m ² . Be prepared. Further, as described above, since the surface roughness of the cloth on which the metal conductive pattern is formed is a smooth surface of 100 μm or less, the pattern portion is broken due to the height difference of the unevenness and the conductivity is impaired. Nor. In the case of containing the adhesive layer or the binder resin as in Patent Documents 2 to 5 described above, the metal purity of the coating film generally remains at about 80%, so that the pattern portion is 1 as in the present invention. It is not possible to achieve features such as weight per unit area of ~ 100 g / m ² and conductivity with a surface resistance value of 50 Ω / □ or less.

In the method for producing a conductive fabric according to the embodiment of the present invention, a cover coat (protective film) may be further formed on the formed metal conductive pattern depending on the final intended use. The cover coat may be formed, for example, so as to cover at least the metal conductive pattern, or may be formed so as to cover a portion of the fabric having a surface roughness of 100 μm or less, an entire surface of the fabric, or the like. The cover coat is formed mainly for the purpose of insulating, waterproofing and / or preventing tearing of the metal conductive pattern formed on the fabric.

The resin material used for the cover coat is not particularly limited, but is preferably a urethane-based resin, a silicone-based resin, or the like. More specifically, polyurethane resin, silicone resin and the like can be mentioned. More specifically, examples thereof include polyether polyurethane.

The thickness of the cover coat is about 5 to 20 μm. If the thickness of the cover coat is too thick, the effect exhibited by the conductive fabric of the present invention may be impaired, and if it is too thin, the effects of insulation, waterproofing and / or tear prevention may be insufficient.

<Conductive fabric>
The conductive cloth according to the embodiment of the present invention is a conductive cloth manufactured by the above-mentioned method. Therefore, a cloth having a cloth surface roughness (height difference of unevenness on the cloth surface) of at least a part of at least one side of the cloth is 100 μm or less, and 1 to 100 g arranged at a predetermined place within the range of the cloth. A metal conductive pattern of / m ² is provided, and the surface resistance value of the metal conductive pattern is 50 Ω / □ or less. Specifically, for the metal conductive pattern, as described in the steps (ii) and (iii) of the above-mentioned manufacturing method, the metal nanoparticle ink is applied to a predetermined portion within the range of at least a part thereof. It was formed after firing.

As described above, in order to achieve a weight per unit area of 1 to 100 g / m ² and a surface resistance value of 50 Ω / □ or less for the metal conductive pattern formed on the surface of the fabric, a binder resin or the like is included. It cannot be achieved by a manufacturing method using a general metal paste as described above, and a pattern is formed on a smooth cloth surface using a metal nanoparticle ink as in the method according to the embodiment of the present invention described above. By forming, the metal purity is increased and achieved. The metal purity of the metal conductive pattern is preferably 95% or more, more preferably 96% or more, still more preferably 97% or more, still more preferably 98% or more.

Further, preferably, a cationic surfactant is applied to a range including at least a predetermined portion of the fabric. Here, "the cationic surfactant is applied" is a range including a portion of the fabric in which the metal conductive pattern is arranged, as described in the steps (ii) and (iii) of the above-mentioned production method. Is cation-treated in advance, and then the metal nanoparticles ink is applied and fired to finally form a metal conductive pattern. In some cases, the dispersant and the cationic surfactant in the metal nanoparticles ink are partially formed. It means that the metal is applied to the surface of the cloth including at least a predetermined portion thereof and / or, in some cases, to the gaps of the cloth in a state of appropriately reacting. Such a state greatly differs depending on the type of the cationic surfactant, the specific method of the cationic treatment, the reaction system between the cationic surfactant and the dispersant in the metal nanoparticles ink, and the like. Therefore, considering the vast amount of publicly known techniques, it is practically impractical to make a general microscopic direct identification with a more specific structure or characteristic.

FIG. 1 is a perspective view showing an example of a schematic configuration of a conductive fabric according to an embodiment of the present invention. As shown in FIG. 1, the conductive cloth 10 is composed of the cloth 2 and the metal conductive pattern 3. FIG. 2 is a schematic configuration diagram showing a part of the cross section of the line AA shown in FIG. As shown in FIG. 2, the cross section of the conductive cloth 10 has a structure in which a metal conductive pattern 3 is formed on the cloth surface of the cloth 2. FIG. 2 t1 shows the fabric surface roughness only in the cross-sectional portion shown in FIG. 2 of the fabric 2, which is 100 μm or less. In practice, the surface roughness of the fabric measured in all the vertical (90 °) / horizontal (0 °) / diagonal (45 °) directions with respect to the range on the surface of the fabric 2 containing at least the metal conductive pattern 3 The roughness (height difference of the unevenness on the surface of the fabric) is 100 μm or less. T2 in FIG. 2 shows the thickness of the metal conductive pattern 3 and is about 1 to 10 μm, and the weight of the metal conductive pattern 3 formed on the surface of the cloth 2 is 1 to 100 g / 100 g / unit. It is m ² . T3 in FIG. 2 shows the thickness of the fabric 2 itself. However, to be precise, it is assumed that the fabric surface roughness of the fabric 2 may change slightly depending on the coating process and / or the firing process at the time of manufacturing described above, and further, the thickness of the metal conductive pattern 3 also increases. It should be understood that FIG. 2 is only a schematic diagram for explanation because it is not always formed evenly.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but these are not limited to the present invention.

<Manufacturing of conductive fabric>
An example of the method for manufacturing a conductive fabric according to the present invention will be described. The conductive cloth produced by the method in this step is referred to as the conductive cloth of Example 1. FIG. 3 is a flowchart showing a manufacturing process of the conductive fabric of Example 1. FIG. 4 is a diagram showing an outline of each manufacturing process of the conductive fabric of Example 1. Hereinafter, each manufacturing process will be described in detail with reference to these figures.

First, a fabric having a desired fabric surface roughness was prepared (S1 in FIG. 3). As the fabric to be used, polyethylene terephthalate (PET) fibers in which three 56dTex144 filaments are twisted together for both warp and weft are used to make a woven fabric with 2 x 2 twill (density: 27 horizontal / cm, 60 vertical / cm). Was used. In order to smooth the surface of the fabric, as shown in FIG. 4 (1), the surface of the fabric 2 is pressed at 160 ° C. and 8.0 MPa using a flat heat press machine 4 for 60 seconds. Heat compression processing was performed. The fabric surface roughness of the fabric 2 after the heat compression process was measured by a surface roughness measuring machine "SV-3000CNC" (trade name, manufactured by Mitutoyo Co., Ltd.) and found to be 50 μm.

Next, the cloth was treated with cations (S2 in FIG. 3). Lauryltrimethylammonium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) was used as a cationic surfactant. As shown in FIG. 4 (2), the above-mentioned heat-compressed fabric 2 is immersed in a 20% aqueous solution of lauryltrimethylammonium chloride 5, squeezed with a mangle 6, and then dried with warm air at 80 ° C. for 10 minutes. Was done.

Then, silver nanoparticle ink was printed on the surface of the fabric by inkjet, and the solvent of the ink was dried (S3 in FIG. 3). As a silver nanoparticle ink, "NBSIJ-KC01" (trade name, manufactured by Mitsubishi Paper Co., Ltd. (silver 17% by mass, ethylene glycol 30-40% by mass, ethanol 1-2% by mass, isopropyl alcohol less than 1% by mass, water 30- Contains 50% by mass and 1 to 5% by mass of other additives. Average particle size of silver nanoparticles (calculated average value of spherical equivalent particle size of 100 particles measured by a transmission electron microscope) is 100 nm)) Was used. As shown in FIG. 4 (3), an inkjet printing machine 7 (“SIT-SP-M10” (trade name, manufactured by Seiren Co., Ltd.)) is used at a desired conductive pattern portion on the fabric surface of the fabric 2, and 40 pl / The conductive pattern printed image was overlaid twice with a dot ejection amount and a resolution of 600 dpi. Then, the cloth 2 on which the conductive pattern was printed was dried with warm air at 80 ° C. for 1 minute.

Finally, light firing with a xenon flash was performed (S4 in FIG. 3). Specifically, as shown in FIG. 4 (4), the dough surface of the above-mentioned dried cloth 2 using a xenon flash light firing device 8 (“S-2210” (trade name, manufactured by Xenon)). An irradiation energy of 20 J / cm ² was applied to the woven fabric over an irradiation time of 3 ms, and firing was performed. As a result, a silver metal conductive pattern 3 having a surface resistance value of 5 Ω / □ or less was formed on the surface of the cloth 2. The surface resistance value was measured by "Lorester-EP MCP-T360" (trade name, manufactured by Mitsubishi Chemical Analytec Co., Ltd.). The formed metal conductive pattern 3 is a difference obtained by measuring the weight per unit area of 9.7 g / m ² (the weight of the cloth 2 before and after the formation of the metal conductive pattern 3 is measured by "AUW220D" (trade name, manufactured by Shimadzu Corporation)). It was a value calculated from the total amount of the metal conductive pattern 3).

<Measurement of metal purity of metal conductive pattern>
In the conductive cloth according to the present invention, only metal nanoparticle ink having an average particle diameter of 200 nm or less is applied on a smooth cloth surface in the manufacturing process, and the metal purity of the pattern after firing is high. It has sufficient conductivity even if it is light in weight. Therefore, the metal purity of the formed metal conductive pattern was measured for the conductive fabric of Example 1 manufactured by the above-mentioned method.

In order to measure the metal purity of the metal conductive pattern formed in the conductive cloth of Example 1, a step of using slide glass instead of the cloth on the surface under the same conditions (same as the same silver nanoparticle ink). A metal conductive pattern was formed through inkjet printing under the same quantity and conditions and light firing with a xenon flash under the same conditions). As a result of measuring the metal purity of the formed metal conductive pattern sample according to Example 1 by removing impurities by the ignition residue test method described in JIS K 0067: 1992, the metal purity was 95% or more.

<Evaluation of surface resistance (conductivity) in relation to the surface roughness of the fabric>
Since the conductive cloth according to the present invention has a smooth surface with a cloth surface roughness of 100 μm or less on which the metal conductive pattern is formed, even if the metal nanoparticles ink is applied to form the metal conductive pattern, the metal conductive pattern may be formed. Conductivity can be ensured without disconnection in the pattern due to the height difference of the unevenness. Therefore, in Examples and Comparative Examples, the surface resistance value of the metal conductive pattern of the conductive cloth in relation to the cloth surface roughness (height difference of the unevenness of the cloth surface) was evaluated.

The conductive cloth of Example 1 is a conductive cloth manufactured by the above-mentioned method.

In the conductive fabric of Example 2, a polyethylene terephthalate (PET) fiber having 84 dTex336 filaments for both warp and weft was used as the fabric, and the fabric was woven by plain weave (density: 39 horizontal / cm, 65 vertical / cm). It was used. The fabric surface roughness of the fabric is 30 μm without smoothing (measured by the surface roughness measuring machine “SV-3000CNC” (trade name, manufactured by Mitutoyo Co., Ltd.)), and it can be used as it is without pretreatment such as compression processing. The metal conductive pattern was formed by the same method as the above-mentioned manufacturing process of the conductive cloth of Example 1. The surface resistance value of the formed metal conductive pattern was 0.4 Ω / □ or less (measured by "Lorester-EP MCP-T360" (trade name, manufactured by Mitsubishi Chemical Analytech Co., Ltd.)). Since there is no difference from the conductive cloth of Example 1 other than the used cloth, the weight per unit area of the metal conductive pattern and the metal purity are the same values.

In the conductive woven fabric of Comparative Example 1, a woven fabric similar to that used for the conductive woven fabric of Example 1 (polyethylene terephthalate (PET) fiber in which three 56dTex144 filaments are twisted together for both warp and weft is used. The 2 × 2 twill (density: 27 horizontal lines / cm, 60 vertical lines / cm) woven fabric was used without smoothing. The fabric surface roughness of the fabric was 220 μm (measured by a surface roughness measuring machine “SV-3000CNC” (trade name, manufactured by Mitutoyo Co., Ltd.)). A metal conductive pattern was formed by the same method as in the manufacturing process of the conductive fabric of Example 1 described above. The surface resistance value of the formed metal conductive pattern was 1.999 MΩ / □ or more, which is the upper limit of the measurement range of the measuring instrument (measured by "Lorester-EP MCP-T360" (trade name, manufactured by Mitsubishi Chemical Analytech)). ). Since there is no difference from the first embodiment except for the cloth used, the weight per unit area of the metal conductive pattern and the metal purity are the same values.

Table 1 below summarizes the evaluation results such as the surface resistance value of the metal conductive pattern for the conductive fabrics of Example 1, Example 2, and Comparative Example 1.

As can be seen from Table 1, the conductive fabrics of Example 1 (fabric surface roughness: 50 μm) or Example 2 (fabric surface roughness: 30 μm) each have a surface resistance value of 5 Ω / □ or less or 0.4 Ω. It is less than / □ and has sufficient conductivity. However, in the conductive fabric of Comparative Example 1 (fabric surface roughness: 220 μm), the surface resistance value was 1.999 MΩ / □ or more, which is the upper limit of the measurement range, and the conductivity was lost. It can be inferred that this is because in Comparative Example 1, the pattern portion was broken due to the height difference of the unevenness.

<Evaluation of air permeability in relation to the surface roughness of the fabric>
As described above, the conductive fabric according to the present invention has a fabric surface roughness of at least a part of the fabric used for ensuring conductivity of 100 μm or less, and the fabric surface roughness is remarkably large. It is presumed that the air permeability is lower than that of. Therefore, in order to evaluate the practicality when used as a conductive cloth, the air permeability of the cloth (without metal conductive pattern) in Examples and Comparative Examples was evaluated.

The air permeability of each of the following fabrics to be evaluated was measured. The air permeability was measured using a "FX3300" (trade name, manufactured by TEXTEST INSTRUMENTS) as a measuring machine at a test pressure of 125 Pa (JIS L 1096-A standard).
-Cloth A: The cloth used for the above-mentioned conductive cloth of Comparative Example 1 (fabric surface roughness: 220 μm).
Heat-compressed fabric A: The fabric used for the conductive fabric of Example 1 described above (fabric surface roughness: 50 μm).
Fabric B: The fabric used for the conductive fabric of Example 2 described above (fabric surface roughness: 30 μm).

FIG. 5 is a diagram showing the results of air permeability measurement of the fabrics according to Examples and Comparative Examples. As shown in FIG. 5, the air permeability of the heat-compressed cloth A (the cloth of Example 1) having a cloth surface roughness of 50 μm and the cloth B (the cloth of Example 2) having a cloth surface roughness of 30 μm Compared with 40.8 cm ³ / cm ² / s of cloth A (cloth of Comparative Example 1) having a cloth surface roughness of 220 μm, 4.3 cm ³ / cm ² / s or 5.0 cm ³ / cm, respectively. It was ² / s, and the air permeability was somewhat low. However, it has been found that it has sufficient air permeability in practical use when used as a conductive fabric.

Unless otherwise defined, all technical terms and the like used herein have the same meanings as commonly understood by those skilled in the art to which the present invention belongs. Methods and materials similar to or equivalent to those described herein can be used in the practice or testing of the present invention. All publications and patents referred to herein are incorporated by reference in their entirety. In case of conflict, this specification, including the definition, prevails. Moreover, the materials, methods and examples are merely exemplary and are not intended to be limiting.

The present invention is not limited to the description of the embodiments and examples of the above invention. Various modifications are also included in the present invention to the extent that those skilled in the art can easily conceive without departing from the description of the scope of claims.

According to the method for manufacturing a conductive cloth according to the present invention, the weight per unit area of the metal conductive pattern formed on the cloth is light, the characteristics of the original air permeability of the cloth are easily maintained, and the metal conductive pattern is disconnected. Provided is a conductive fabric having sufficient conductivity without causing the occurrence of. Such a conductive fabric can be suitably used as a base material for a wearable device or the like.

2 Cloth 3 Metal conductive pattern 4 Flat heat press machine 5 Cationic treatment solution 6 Mangle 7 Inkjet printing machine 8 Xenon flash light firing device 10 Conductive cloth

Claims (6)

(I) A step of preparing a fabric having a fabric surface roughness (height difference of unevenness on the surface of the fabric) of at least one side of the fabric of 30 μm or more and 100 μm or less.
The step of cation-treating a range including a predetermined portion within at least a part of the range.
(Ii) After the cation treatment step , the average particle size (arithmetic mean value of the sphere-equivalent particle size of 100 particles measured by a transmission electron microscope) is determined at a predetermined location within at least a part of the range. The process of applying a dispersion of metal nanoparticles of 200 nm or less, and
(Iii) At least including a step of calcining the predetermined portion coated with the dispersion liquid to form a metal conductive pattern of 1 to 100 g / m ² .
The surface resistance value of the metal conductive pattern is 50 Ω / □ or less.
A method for manufacturing a conductive fabric. Prior to the step (i), a pretreatment step of smoothing by compression of the cloth is further included, and the pretreatment step further includes a cloth surface roughness (the unevenness of the cloth surface) of at least a part of at least one side of the cloth. The method for producing a conductive fabric according to claim 1 , wherein a fabric having a height difference of 100 μm or less is prepared. The method for producing a conductive fabric according to claim 1 or 2 , which is applied by inkjet printing in the step (ii). A fabric having a fabric surface roughness (difference in height of unevenness on the surface of the fabric) of at least one side of the fabric of 30 μm or more and 100 μm or less.
It comprises at least a metal conductive pattern of 1 to 100 g / m ² arranged at a predetermined position within at least a part of the range.
The surface resistance value of the metal conductive pattern is 50 Ω / □ or less, and is
A cationic surfactant is applied to a range of the fabric including a predetermined portion within the range of at least a part thereof.
Conductive fabric. The conductive fabric according to claim 4 , wherein the metal purity of the metal conductive pattern is 95% or more. The conductivity according to claim 4 or 5 , wherein the range in which the fabric surface roughness (height difference of the unevenness of the fabric surface) in the fabric is 100 μm or less is a breathability of 0.1 to 20 cm ³ / cm ² / s. Sexual fabric.

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