JP6293065B2 - Electronic circuit sheet - Google Patents

Description

  The present invention relates to an electronic circuit creation sheet suitable for drawing a circuit diagram using conductive ink.

  In recent years, the technology of printed electronics has been progressing. Printed electronics is a technology that prints information (characters, illustrations, photographs) mainly on conventional media, while inkjet recording (droplets are ejected from nozzles onto the media). It is a general term for technologies that draw or stack various substances on a medium by a method of attaching) to give functions other than information. For example, along with the advancement of the hardware aspect of inkjet printers, ink is not limited to color inks for drawing simple lines, and conductive inks are being developed, and it is now possible to draw electronic circuits easily. is there. Examples of the substance that can be a main component of the conductive ink include metal particles (gold, silver, copper, etc.) and carbon particles (grefen, carbon nanotube, graphite).

  Currently, an ink in which silver particles are atomized to the nano level (hereinafter abbreviated as silver ink) has appeared as the conductive ink. For example, a conductive ink marker (Silver Ink Marker) manufactured by AgIC is commercially available as a pen filled with such silver ink. When the electric resistance of the image area due to the silver ink is lowered, conductivity is developed, and an electronic circuit can be manufactured. If an electronic circuit can be formed on the surface of a sheet such as paper, the electronic circuit can be reduced in weight and thinned, and further, a disposable electronic component or electrical product can be manufactured. Also, for example, it can be used as a teaching material for electronic circuits, and its application fields are wide. In addition, when the base material of the electronic circuit creation sheet is paper, it is ecological and environmentally friendly, and can be destroyed by hand, so that information recorded on the electronic circuit can be easily destroyed and security is excellent. As such a sheet for creating an electronic circuit, Patent Document 1 discloses a sheet in which a receiving layer containing a porous inorganic filler is provided on a base material.

  However, the sheet disclosed in Patent Document 1 requires a drying process for a relatively long time after drawing a circuit pattern with conductive ink, or drying by heating. In addition, in order for an electronic circuit drawn with conductive ink to exhibit conductivity, it is necessary to form a film with a relatively large thickness using conductive ink, for example, by repeatedly drawing at the same location as overwriting. was there. Therefore, it cannot be said that it is necessarily appropriate for use in ink-jet printing using conductive ink or drawing of circuits by handwriting.

JP 2004-127851 A

  Therefore, an object of the present invention is to form a film having a large film thickness with a conductive ink without drawing a heating or long-time drying process when an electronic circuit is produced by drawing with a conductive ink on a sheet surface. An object of the present invention is to provide a sheet for producing an electronic circuit in which the drawn electronic circuit can exhibit conductivity. Another object of the present invention is to provide a sheet for producing an electronic circuit that maintains the conductivity of the drawn electronic circuit for a long time and has high stability as an electronic circuit over time.

  As a result of the study by the present inventor, for example, in the case of commercially available copy paper or matte coated paper, it has been found that the electronic circuit drawn on the paper surface with conductive ink has no electrical conductivity. This is because the unevenness of the surface of the paper is so large that the adhesion of silver particles in the silver ink is hindered and the absorbability of the ink on the paper is too high. It is presumed that this is caused by the fact that the silver particles in the silver ink are absorbed together with the components and hardly remain on the paper surface. In order to avoid this phenomenon, it is considered that a certain density is required on the sheet surface on which the conductive ink is drawn.

  Therefore, an electronic circuit creation sheet according to the present invention is an electronic circuit creation sheet for drawing an electronic circuit using a conductive ink, and a fine particle and a binder are provided on at least one side of a substrate. A coating layer to be contained is provided, the fine particles are at least one selected from silica, alumina, and boehmite, and the coating layer is a cast coating layer.

  In the present invention, the silica may be gas phase method silica and / or colloidal silica having a primary particle diameter of 5 to 100 nm. The conductivity of the electronic circuit drawn using the conductive ink is further improved.

  The present invention can also be regarded as a method for producing an electronic circuit forming sheet. The method for producing a sheet for producing an electronic circuit of the present invention comprises a step of coating a coating liquid containing at least one kind of fine particles selected from silica, alumina and boehmite and a binder on at least one surface of a substrate. And a step of pressure-bonding the coating film obtained by coating the coating liquid to the mirror surface in a wet state of the coating film and drying to obtain a coating layer. And

  Further, in the step of obtaining the coating layer, a coating solution containing a component that solidifies the coating film is applied to the coating film while the coating film is in a wet state after the coating liquid is applied. Alternatively, it is preferable to impregnate, then press-bond to the mirror body and dry to obtain a coating layer. The conductivity of the electronic circuit drawn using the conductive ink is further improved.

  In the electronic circuit forming sheet of the present invention, when an electronic circuit is drawn with a conductive ink, the drawn electronic circuit can exhibit conductivity without requiring heating or a long drying process. That is, after drawing an electronic circuit with a conductive ink, the conductive circuit exhibits conductivity in a relatively short time even if it is naturally dried. In addition, even if the film thickness of the conductive ink is relatively small, the electronic circuit drawn with the conductive ink can exhibit conductivity. Appropriately used when drawing an electronic circuit with a pen filled with the conductive ink (for example, by handwriting) or drawing an electronic circuit with the conductive ink filled in an ink jet printer cartridge (inkjet printing) Can do. In addition, since the conductivity of the drawn electronic circuit is maintained for a long time, it is possible to create an electronic circuit with excellent stability over time. Furthermore, in the present invention, when paper is used as a base material, it is easier to recycle at the time of disposal than when a film or plastic is used as a base material, which is preferable from the viewpoint of effective use of resources. Since it can be easily destroyed by hand, the information recorded in the electronic circuit can be easily destroyed, and the security is excellent.

  Next, the present invention will be described in detail with reference to embodiments, but the present invention is not construed as being limited to these descriptions. As long as the effect of the present invention is exhibited, the embodiment may be variously modified.

  As the base material used in the present invention, a non-woven fabric or paper having air permeability can be used. Examples of the paper include high quality paper, medium quality paper, and paperboard. Either acidic paper or neutral paper can be used. Pulp fibers used for paper (paper substrate) as a base material are chemical pulps such as LBKP (hardwood bleached kraft pulp), NBKP (softwood bleached kraft pulp), GP (crushed wood pulp), PGW (pressurized groundwood pulp), RMP (refiner mechanical pulp), TMP (thermomechanical pulp), CTMP (chemithermomechanical pulp), CMP (chemimechanical pulp), mechanical pulp such as CGP (chemiground pulp), wood pulp such as DIP (deinked pulp) And non-wood pulp such as kenaf, bagasse, bamboo, and cotton. These can be used alone or in admixture at any ratio. In addition, a synthetic fiber can be further blended within a range that does not impair the intended effect of the present invention. From the viewpoint of environmental conservation, it is desirable to use ECF (Elemental Chlorine Free) pulp or TCF (Totally Chlorine Free) pulp, waste paper pulp, and pulp obtained from planted trees with low environmental impact. Fillers used for paper bases include heavy calcium carbonate, light calcium carbonate, magnesium carbonate, titanium oxide, synthetic silica, alumina, talc, calcined kaolin clay, kaolin clay, bentonite, zeolite, aluminum hydroxide, oxidation Known fillers such as zinc can be used.

In addition, when paper is used as the base material, the raw pulp preparation method and each papermaking chemical addition method are not particularly limited as long as the effects of the present invention are not impaired. The paper substrate can be produced by applying a known paper machine such as a circular paper machine, a long paper machine, or a twin wire paper machine, and may be a single-layer paper or a multi-layer paper. The basis weight of the substrate is not particularly limited, but is preferably 30 to 300 g / m ^{2 in} consideration of drawing suitability (paper feeding suitability) with a printer.

  In the present invention, at least one coating layer containing fine particles and a binder is provided on at least one surface of the substrate. As the fine particles used here, one type or two or more types selected from silica, alumina, and boehmite are used. Silica, alumina, and boehmite are relatively porous fine particles, and by incorporating these in the coating layer, a porous coating layer having good liquid absorption can be obtained.

  Silica used as the fine particles is preferably gas phase method silica and / or colloidal silica having a primary particle diameter of 5 to 100 nm. The coating layer becomes more porous, and a porous coating layer having good liquid absorbability can be obtained.

  Vapor phase method silica is also called dry method silica or fumed silica, and is generally produced by flame hydrolysis. Specifically, it is manufactured by gas phase hydrolysis of volatile silane compounds such as silicon tetrachloride in an oxyhydrogen flame, and conditions such as flame temperature, supply ratio of oxygen and hydrogen, supply of raw material silicon tetrachloride, etc. Obtained by changing. Since the electrical conductivity is good, the average primary particle diameter of the vapor phase method silica is preferably 5 to 30 nm, and more preferably 6 to 20 nm.

Moreover, it is preferable that the BET specific surface area of vapor-phase method silica is 50-500 m < ² > / g. More preferably, it is 70-450 m < ² > / g, Most preferably, it is 80-400 m < ² > / g. By using gas phase method silica having a BET specific surface area of 50 m ² / g or more, the drying property of the conductive ink can be further improved. However, if the BET specific surface area exceeds 500 m ² / g, the conductive ink may sink too much into the coating layer and the conductivity of the produced electronic circuit may be inferior. Here, the BET specific surface area is a surface area per unit mass determined by the BET method. The BET method is a method for measuring the specific surface area of a powder by a gas phase adsorption method, and is a method for obtaining the total surface area, that is, the specific surface area of a 1 g sample from an adsorption isotherm. Usually, nitrogen gas is often used as the adsorbed gas, and the most frequently used method is to measure the amount of adsorption from the change in pressure or volume of the gas to be adsorbed. The most prominent expression for expressing the isotherm of multimolecular adsorption is the Brunauer, Emmett, and Teller equation, called the BET equation, which is widely used for determining the surface area. The adsorption amount is obtained based on the BET equation, and the surface area is obtained by multiplying the area occupied by one adsorbed molecule on the surface.

  The colloidal silica having a primary particle diameter of 5 to 100 nm is preferably spherical colloidal silica (primary particles) having a primary particle diameter of 5 to 100 nm, for example, a primary particle diameter of 10 to 50 nm. The coating layer becomes more porous, and a porous coating layer having good liquid absorbability can be obtained. Agglomerated non-spherical colloidal silica in which a plurality of primary particles are randomly bonded, non-spherical colloidal silica in which a plurality of primary particles are bonded in a pearl necklace shape, and non-spherical colloidal silica in which a plurality of primary particles are bonded in a tuft shape. Nonspherical colloidal silica which is secondary particles such as can be used as appropriate. The secondary particle diameter of the non-spherical colloidal silica is preferably 30 to 800 nm, for example, the secondary particle diameter is preferably 50 to 200 nm because appropriate pores are formed in the receiving layer.

  As the alumina used as the fine particles, alumina having a known crystal structure such as γ-alumina, θ-alumina, and σ-alumina can be used. Boehmite is alumina having a boehmite crystal structure, but any boehmite structure or pseudo-boehmite structure can be used as long as it shows a boehmite structure by an X-ray diffraction method, and is not particularly limited. In the present invention, it is particularly preferable to use γ-alumina and boehmite because a coating layer having higher liquid absorption can be obtained.

  Examples of the binder contained in the coating layer include polyvinyl alcohol (including modified polyvinyl alcohols such as carboxyl-modified polyvinyl alcohol and silanol-modified polyvinyl alcohol), polyvinyl acetal, oxidized starch, etherified starch, carboxymethylcellulose, and hydroxyethylcellulose. , Casein, gelatin, soy protein, polyethyleneimide resin, polyvinylpyrrolidone resin, polyacrylic acid or copolymers thereof, maleic anhydride copolymer, acrylamide resin, acrylate resin, polyamide resin, acrylic resin Resin, styrene-acrylic resin, polyurethane resin, polyester resin, polyvinyl butyral resin, alkyd resin, epoxy resin, epichlorohydrin resin, styrene-butyl resin Acrylic polymer latex such as diene copolymer, methyl methacrylate-butadiene copolymer, acrylic acid ester, methacrylic acid ester polymer or copolymer, and vinyl polymer such as ethylene-vinyl acetate copolymer Examples thereof include latex, composite resin of colloidal silica and acrylic resin, composite resin of colloidal silica and styrene-acrylic resin, and the like. These are used alone or in combination. It is preferable to contain polyvinyl alcohol from the viewpoint of the drying property of the conductive ink. The amount of the binder used may be determined in consideration of the conductivity of the drawn electronic circuit, the strength of the receiving layer, the glossiness of the surface of the receiving layer, the liquid property of the coating material for the receiving layer, and the like. It is preferable to add in the range of 1 to 200 parts by mass with respect to parts by mass. More preferably, it adds in 2-100 mass parts, More preferably, it is 3-80 mass parts, for example, 3-10 mass parts. If it is less than 1 part by mass, the surface strength of the receptor layer may be lowered. If it exceeds 200 parts by mass, the drying property of the conductive ink may be lowered.

  Further, it is preferable to use silanol-modified polyvinyl alcohol as part or all of the binder. By containing silanol-modified polyvinyl alcohol, cracking of the coating layer is reduced, excessive penetration of the conductive ink into the coating layer is prevented, and conductivity is easily developed. In this invention, it is preferable that the addition amount of this silanol modified polyvinyl alcohol is 0.1-50 mass parts with respect to 100 mass parts of microparticles, for example, 0.5-5 mass parts.

In the electronic circuit forming sheet according to the present invention, the coating layer is a cast coat layer. The cast coat layer can be obtained by a so-called cast coat method. Specifically, the cast coat layer is obtained by applying a coating solution for a coating layer to a substrate and applying the coating solution. The coated film can be obtained by pressure-bonding the coated film to the mirror body in a wet state and drying. As the cast coating method, a wet method, a coagulation method, and a rewet method are known, and any of these methods can be used. Among these cast coating methods, it is preferable to obtain a cast coating layer by a coagulation method. In the solidification method, a coating liquid for a coating layer is applied to a substrate, and the coating film obtained by applying the coating liquid is solidified (gel) while the coating film is in a wet state. To solidify by applying or impregnating a coagulating liquid containing the component to be converted, and while the coagulated coating film is in a wet state, it is pressed against a mirror body (heated metal mirror surface) such as a cast drum and dried. It is a method to do. In the coagulation treatment, it is important to select a component that coagulates the coating film (coagulant) that effectively coagulates with the binder component of the coating layer. As the coagulation liquid, it is preferable to use an aqueous solution containing 1 to 10% by mass of a coagulant. If it is less than 1% by mass, the surface strength of the coating layer may be reduced. Moreover, it is preferable that it is 1 mass% or more with respect to the binder which can be solidified, for example, 5 mass% or more. As the coagulant, a boron compound is preferable. More preferably, either or both of sodium borate and boric acid are used. In the production method of the present invention, specifically, after coating the coating liquid for the coating layer and providing the coating film, while the coating film is in a wet state, the absolutely dry coating amount Is applied to the coating film so as to be 0.3 to 5.0 g / m ² , for example, 0.5 to 2.0 g / m ^2, and then the coating film is solidified, and then the solidification process is performed. While the applied coating film is in a wet state, it is dried by pressing onto a cast drum having a surface temperature of 90 to 120 ° C., for example, 105 ° C. In the case of the coagulation method, since many fine pores are formed in the receiving layer after drying, the particles that are the main component of the conductive ink remain on the surface of the coating layer and are likely to exhibit conductivity. it is conceivable that. In the present invention, it is also possible to use a so-called rewet method in which a coating liquid for a coating layer is applied and dried, and then the coating layer is wetted with a rewet liquid and pressed against a cast drum. It is.

  In the present invention, colloidal silica can be contained in both the coagulating liquid and the rewet liquid in order to improve image clarity. By including colloidal silica in the coagulation liquid and rewet liquid, the surface of the coating layer has a smooth touch and a sheet for producing an electronic circuit having excellent image clarity can be obtained. By improving the image clarity of the electronic circuit creation sheet, it is possible to improve the conductivity of the electronic circuit drawn with the conductive ink. In the present invention, a binder can be contained in both the coagulating liquid and the rewetting liquid in order to improve the image clarity.

  In the present invention, the coating solution for the coating layer includes a dispersant, a thickener, an antiseptic, an antifoaming agent, a coloring dye, a coloring pigment, a fluorescent substance, as long as the effects of the present invention are not impaired. Various auxiliary agents such as a brightening agent, a water resistant agent, an antioxidant, and an ultraviolet absorber can be appropriately selected and added.

  In the present invention, the coating liquid for the coating layer is applied to the base paper, but the coating method is not particularly limited, and an air knife coater, roll coater, reverse roll coater, bar coater, Any of known coating machines such as a comma coater, a blade coater, and a simultaneous multilayer coater may be used.

The coating amount (absolute dry mass) of the coating layer is preferably 1 to 50 g / m ² . More preferably, it is 2-45 g / m < ² >, More preferably, it is 5-20 g / m < ² >, for example, 7-15 g / m < ² >. When the coating amount exceeds 50 g / m ² , there is a possibility that the conductivity of the electronic circuit drawn with the conductive ink is inferior, and when the coating amount is less than 1 g / m ² , the drying property of the conductive ink is inferior. There is a fear.

  The electronic circuit forming sheet of the present invention may be subjected to a calendar process such as a machine calendar, a soft calendar, and a super calendar after providing a coating layer by a cast coating method. Water, a curling agent, or the like can be applied to the surface where the work layer is not provided, and curling can be adjusted by humidification.

  In the present invention, an intermediate layer may be provided between the substrate and the coating layer. The intermediate layer may be a layer made only of a resin or a layer containing a pigment. In particular, by providing one or more intermediate layers containing a pigment and a binder, it is possible to obtain a sheet for producing an electronic circuit excellent in the drying property of the conductive ink. In addition, when providing the intermediate layer containing a pigment, it is preferable that the pigment contained in an intermediate layer has as a main component the pigment whose average particle diameter is larger than the fine particle contained in the coating layer which is a cast coat layer. The pigment to be contained in the intermediate layer is not particularly limited, and pigments such as calcium carbonate, talc, and kaolin titanium dioxide can be used in addition to silica, alumina, boehmite. Further, as the resin and binder used for the intermediate layer, the same binders as those used for the coating layer described above can be used.

  Moreover, you may provide a coating layer not only on the single side | surface of a base material but on both surfaces. Electronic circuits can be drawn on both sides of the electronic circuit creation sheet.

  Furthermore, in the present invention, the image clarity of the coating layer under the condition of an optical comb width of 2 mm and an incident reflection angle of 60 ° according to JIS H 8686-2: 1999 “Image quality test method of anodized film of aluminum and aluminum alloy” is 40. % Or more is preferable from the viewpoint of conductivity. High image clarity means high optical smoothness on the surface of the coating layer, less irregularities on the surface of the coating layer, and fine pores. Conductivity of electronic circuits drawn with conductive ink Can be obtained. Here, the reason for changing the incident / reflective angle from 45 ° described in JIS to 60 ° is to facilitate evaluation of the difference in image clarity.

  As described above, the electronic circuit creation sheet of the present invention contains at least one selected from silica, alumina, and boehmite as fine particles in the coating layer, and the coating layer is used as a cast coating layer. After the electronic circuit is drawn with the conductive ink, the conductive circuit can exhibit conductivity in a relatively short time even by natural drying. This is because the cast coat layer containing fine particles with high liquid absorbency quickly absorbs the solvent of the drawn conductive ink, and on the surface of the coating layer of the conductive particles contained in the conductive ink. It is presumed that this contributes to rapid adhesion. If the solvent of the conductive ink is not absorbed quickly, the conductive particles do not sufficiently adhere to each other, and if the conductive ink dries without the solvent being sufficiently absorbed, substances other than the conductive particles contained in the solvent Inhibits the adhesion between the conductive particles, and the electronic circuit cannot exhibit conductivity. The electronic circuit forming sheet of the present invention is also characterized in that the electronic circuit exhibits conductivity even when the film thickness of the electronic circuit drawn with the conductive ink is relatively small. This is because the coating layer dried by the Casco Coat method has high image clarity, and the adhesion between the conductive particles is physically hindered because there are few irregularities on the surface of the coating layer. It is difficult (the conductive particles are easy to arrange in a plane), and furthermore, the fine particles contained in the coating layer are rich in liquid absorption, but the size of each pore is relatively small. It is presumed that the conductive particles are buried relatively little inside. Further, the electronic circuit producing sheet of the present invention is characterized in that the conductivity of the drawn electronic circuit is maintained for a long time. This is because there are few irregularities on the surface of the coating layer, and the condition that the adhesion between the conductive particles is not physically hindered is satisfied. In addition, the adhesion between the fine particles contained in the coating layer and the conductive particles Strong is considered to be a factor.

EXAMPLES Next, although an Example is given and this invention is further explained in full detail, this invention is not limited to these examples. Further, “parts” and “%” shown in the examples represent solid mass parts and solid mass%, respectively, unless otherwise specified.

Example 1
(Creation of base material)
5 parts by mass of talc (T-light 83: Taihei Talc Co., Ltd.) as a filler for pulp slurry in which 100 parts by mass of L-BKP (hardwood bleached kraft pulp) beaten in 530 ml of Canadian Standard Freeness (CSF) was dispersed in water, Add 1.0 parts by mass of sulfuric acid band, 0.25 parts by mass of acidic rosin sizing agent (AL-1200: manufactured by Seiko PMC), 1.0 part by mass of cationized starch (Neotac 40T: manufactured by Nippon Food Processing Co., Ltd.) The raw material slurry was obtained by dispersing. Using the obtained raw slurry, paper making was performed using a long net paper machine to obtain a paper web. Thereafter, oxidized starch (MS # 3800: manufactured by Nippon Food Processing Co., Ltd.) was applied to both sides of the paper web with a size press so that the dry coating amount was 1.0 g / m ² per side, dried, and basis weight. A fine paper of 170 g / m ² was obtained.

(Formation of intermediate layer)
100 parts by mass of silica (nip gel AZ-410, average particle size 4.0 μm, pore volume 1.8 cm ³ / g, manufactured by Tosoh Silica Co.) as a pigment, and polyvinyl alcohol (PVA 117: manufactured by Kuraray Co., Ltd.) as a binder An intermediate layer coating material having a solid content concentration of 20% by mass comprising 20 parts by mass and 50 parts by mass of ethylene-vinyl acetate (Polysol EVA AD-10: Showa Polymer Co., Ltd.) was obtained. Subsequently, this intermediate layer coating material was applied to one surface of the fine paper with an air knife coater so that the dry coating amount was 10 g / m ^2, and dried to provide an intermediate layer.

(Formation of coating layer)
Next, 100 parts by mass of non-spherical colloidal silica (Snowtex PS-MO, primary particle size 18 to 25 nm, secondary particle size 80 to 150 nm: manufactured by Nissan Chemical Industries, Ltd.) as secondary particles as fine particles, and a binder 3 parts by mass of silanol-modified polyvinyl alcohol (PVA-R1130: manufactured by Kuraray Co., Ltd.) and 2 parts by mass of polyurethane resin (Hydran CP-7020: manufactured by Dainippon Ink Industries, Ltd.) are dispersed in water and stirred with a mixer to obtain a solid content. A coating solution for a coating layer having a concentration of 20% was obtained. The coating solution for the coating layer was applied on the intermediate layer with an air knife coater so that the dry coating amount was 10 g / m ² to provide a coating film. Next, an aqueous solution containing 1% boric acid as a coagulant and 1% sodium borate (concentration of the coagulant is 2.0%) is coagulated as a coagulant while the coating film is in a wet state. After coating the coating film so that the dry coating amount is 1 g / m ² and coagulating the coating film, the surface temperature is 105 ° C. while the coating film subjected to the coagulation treatment is in a wet state. A sheet for forming an electronic circuit was produced by pressure bonding to a cast drum and drying.

(Example 2)
In the formation of the coating layer of Example 1, non-spherical colloidal silica (Snowtex PS-MO, primary particle diameter 18 to 25 nm, secondary particle diameter 80 to 150 nm: secondary particles) produced by Nissan Chemical Industries, Ltd. ) A sheet for producing an electronic circuit was produced in the same manner as in Example 1 except that 100 parts by mass was changed to 100 parts by mass of γ-alumina (alumina C, BET specific surface area 100 m ² / g: manufactured by Degussa).

(Example 3)
In the formation of the coating layer of Example 1, non-spherical colloidal silica (Snowtex PS-MO, primary particle diameter 18 to 25 nm, secondary particle diameter 80 to 150 nm: secondary particles) produced by Nissan Chemical Industries, Ltd. ) A sheet for producing an electronic circuit was produced in the same manner as in Example 1 except that 100 parts by mass was changed to 100 parts by mass of boehmite (C01, BET specific surface area 110 m ² / g: manufactured by Daimei Chemical Co., Ltd.).

Example 4
In the formation of the coating layer of Example 1, non-spherical colloidal silica (Snowtex PS-MO, primary particle diameter 18 to 25 nm, secondary particle diameter 80 to 150 nm: secondary particles) produced by Nissan Chemical Industries, Ltd. ) A sheet for producing an electronic circuit was prepared in the same manner as in Example 1 except that 100 parts by mass was changed to 100 parts by mass of vapor-phase process silica (Leosil QS-30, BET specific surface area 300 m ² / g: manufactured by Tokuyama). did.

(Example 5)
In the formation of the coating layer of Example 1, non-spherical colloidal silica (Snowtex PS-MO, primary particle diameter 18 to 25 nm, secondary particle diameter 80 to 150 nm: secondary particles) produced by Nissan Chemical Industries, Ltd. ) A sheet for producing an electronic circuit was prepared in the same manner as in Example 1 except that 100 parts by mass was changed to 100 parts by mass of vapor-phase method silica (CABOPERSE PG-022, BET specific surface area 200 m ² / g: manufactured by CABOT). did.

(Example 6)
In the formation of the coating layer of Example 5, the coagulating liquid contains 1% boric acid as a coagulant and 1% sodium borate, and further spherical colloidal silica (Snowtex 20L, primary particle size 45 nm: Nissan Chemical Industries The same as in Example 5 except that the aqueous solution (concentration of the coagulating liquid is 3.5%) containing 1% of acrylic resin (Viniblanc 2580, manufactured by Nissin Chemical Industry Co., Ltd.) 0.1% Thus, a sheet for producing an electronic circuit was produced.

( Reference Example 7)
In the formation of the coating layer of Example 1, non-spherical colloidal silica (Snowtex PS-MO, primary particle diameter 18 to 25 nm, secondary particle diameter 80 to 150 nm: secondary particles) produced by Nissan Chemical Industries, Ltd. ) A sheet for producing an electronic circuit was produced in the same manner as in Example 1 except that the amount was changed from 100 parts by mass to 100 parts by mass of spherical colloidal silica (Snowtex MP1040, average particle size 100 nm: manufactured by Nissan Chemical Industries, Ltd.).

(Example 8)
Example 1 except that the coagulating liquid of Example 1 was changed to an aqueous solution containing 1% boric acid as a coagulant, 1% sodium borate, and 1% magnesium sulfate (concentration of the coagulating liquid is 3.0%). In the same manner as in Example 1, an electronic circuit preparation sheet was prepared.

(Comparative Example 1)
In Example 1, an intermediate layer was formed, and then a coating layer was not provided as an electronic circuit creation sheet.

(Comparative Example 2)
The high quality paper used in Example 1 was used as an electronic circuit creation sheet.

(Comparative Example 3)
In the formation of the coating layer of Example 1, the coating solution for coating layer was coated on the intermediate layer with an air knife coater so that the absolutely dry coating amount was 10 g / m ^2. In the same manner as in Example 1 except that the coating film was dried with a 105 ° C. air dryer and the coating layer was provided without performing the solidification treatment of the coating film with the coagulating liquid and the drying with the cast drum. Thus, a sheet for producing an electronic circuit was produced.

(Comparative Example 4)
In the formation of the coating layer of Example 1, non-spherical colloidal silica (Snowtex PS-MO, primary particle diameter 18 to 25 nm, secondary particle diameter 80 to 150 nm: secondary particles) produced by Nissan Chemical Industries, Ltd. ) Same as Example 1 except for changing from 100 parts by mass to 50 parts by mass of kaolin (UW-90: manufactured by Engelhard M & C) and 50 parts by mass of light calcium carbonate (Tamapearl 123CS: manufactured by Okutama Kogyo Co., Ltd.) Thus, a sheet for producing an electronic circuit was produced.

  The electronic circuit creation sheets obtained in each of the examples and the comparative examples were subjected to the following evaluation, and the results are shown in Table 1 (Examples) and Table 2 (Comparative Examples).

(1) Image clarity of electronic circuit sheet:
The image clarity was measured in order to evaluate the optical smoothness of the coating layer surface of the electronic circuit forming sheet. The image clarity was measured with an image clarity measuring instrument (ICM-1T: manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS H 8686-2 with an optical comb width of 2 mm and an incident / reflection angle of 60 °.
(2) Conductivity evaluation:
Circuit diagram by hand using a pen (conductive ink marker (made by AgIC)) filled with conductive ink whose main component is silver particles on the coating layer surface of the electronic circuit creation sheet Drawn. The circuit diagram was drawn at a speed of about 2 seconds per 10 cm length of the drawing line, and was drawn without overwriting. After drawing, it was allowed to stand at room temperature of 23 ° C. × 50% rh for 2 minutes, and then a commercially available coin-type lithium battery (model number CR2032) and a commercially available blue LED (blue light emitting diode) were connected to the circuit. Whether the LED emits light was evaluated as follows.
(Double-circle): It is proof that LED emits very brightly and appropriate electrical conductivity is expressed, and it can be put into practical use.
○: The LED emits bright light and is evidence that proper conductivity is expressed, and can be put into practical use.
X: Evidence that the LED does not emit light and does not exhibit electrical conductivity, and is not practical.
(3) Circuit stability evaluation:
After drawing a circuit under the same conditions as in the above-mentioned conductivity evaluation, after leaving it at room temperature of 23 ° C. × 50% rh for 48 hours, it was evaluated as follows depending on whether or not the LED was issued in the same manner as in the above-described conductivity evaluation. .
A: The LED emits extremely bright light, the circuit stability is very excellent, and it can be used practically.
○: The LED emits light brightly, has excellent circuit stability, and can be used practically.
X: LED does not emit light, circuit stability is inferior, and impractical.

As is clear from Table 1, the electronic circuit forming sheets obtained in Examples 1 to 6 and 8 and Reference Example 7 were found to be conductive in the drawn electronic circuit even after 2 minutes of natural drying. On the other hand, in the electronic circuit forming sheets obtained in Comparative Examples 1 to 4, conductivity was not recognized in the drawn circuit.

Claims (9)

An electronic circuit creation sheet for drawing an electronic circuit using a conductive ink,
A coating layer containing fine particles and a binder is provided on at least one side of the substrate,
The fine particles are at least one selected from silica, alumina, boehmite,
And the coating layer is cast-coated layer der is, the image clarity of the coating layer surface (according to JIS H 8686-2, optical comb width 2 mm, measured in incident reflection angle 60 °) is 50% or more An electronic circuit creation sheet characterized by the above. 2. The electronic circuit producing sheet according to claim 1, wherein the silica is vapor phase silica and / or colloidal silica having a primary particle diameter of 5 to 100 nm. Whether the silica is a spherical colloidal silica,
Or
Non-spherical colloidal silica which is a secondary particle having a secondary particle diameter of 30 to 800 nm, and
Agglomerated non-spherical colloidal silica in which a plurality of primary particles are randomly bonded, non-spherical colloidal silica in which a plurality of primary particles are bonded in a pearl necklace shape, or a non-spherical colloid in which a plurality of primary particles are bonded in a tuft shape It is a silica, The sheet | seat for electronic circuit creation of Claim 2 characterized by the above-mentioned. The coating layer contains 3 to 10 parts by mass of the binder with respect to 100 parts by mass of the fine particles, and 0.5 to 5 parts by mass of silanol-modified polyvinyl as the binder with respect to 100 parts by mass of the fine particles. The electronic circuit creating sheet according to claim 1, wherein alcohol is used. An electron whose image clarity (measured in accordance with JIS H 8686-2, with an optical comb width of 2 mm and an incident / reflecting angle of 60 °) of 50% or more for drawing an electronic circuit using a conductive ink A method of manufacturing a circuit creation sheet,
Coating at least one surface of the substrate with a coating liquid containing one or more fine particles selected from silica, alumina and boehmite and a binder;
A step of pressing the coating film obtained by coating the coating liquid onto the mirror surface in a wet state of the coating film and drying to obtain a coating layer;
The manufacturing method of the sheet | seat for electronic circuit creation characterized by having. In the step of obtaining the coating layer, the coating film is coated or impregnated with a coagulating liquid containing a component that solidifies the coating film while the coating film is in a wet state after the coating liquid is applied. 6. The method for producing a sheet for producing an electronic circuit according to claim 5 , wherein the coated layer is obtained by pressure-bonding to a mirror body and then drying. The method for producing a sheet for producing an electronic circuit according to claim 5 or 6 , wherein the silica is vapor phase silica and / or colloidal silica having a primary particle diameter of 5 to 100 nm. Whether the silica is a spherical colloidal silica,
Or
Non-spherical colloidal silica which is a secondary particle having a secondary particle diameter of 30 to 800 nm, and
Agglomerated non-spherical colloidal silica in which a plurality of primary particles are randomly bonded, non-spherical colloidal silica in which a plurality of primary particles are bonded in a pearl necklace shape, or a non-spherical colloid in which a plurality of primary particles are bonded in a tuft shape It is a silica, The manufacturing method of the sheet | seat for electronic circuit creation as described in any one of Claims 5-7 characterized by the above-mentioned. The coating layer contains 3 to 10 parts by mass of the binder with respect to 100 parts by mass of the fine particles, and 0.5 to 5 parts by mass of silanol-modified polyvinyl as the binder with respect to 100 parts by mass of the fine particles. Alcohol is used, The manufacturing method of the sheet | seat for electronic circuit creation as described in any one of Claims 5-8 characterized by the above-mentioned.