JP2005122106A - Circuit pattern forming toner, method of manufacturing same, and circuit pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit pattern forming toner with which a fine conductor pattern can be obtained, a method of manufacturing the same, and a circuit pattern forming method by which a high-precision fine circuit pattern can be formed even after printing on a large number of sheets. <P>SOLUTION: The circuit pattern forming toner contains hydrophobed mixed particles which comprise conductive particles comprising a metal or its oxide and inorganic oxide particles having a smaller particle diameter than the conductive particles and insulating resin layers coating the surfaces of the mixed particles, wherein the insulating resin layers have an electrical property by which the layers are charged to one polarity and the layers are formed by a phase separation process with a nonaqueous emulsion. The toner is obtained by adding conductive particles comprising a metal or its oxide, a charge control material, and an insulating resin to a dispersion medium incompatible with the resin, kneading those under heating at a temperature equal to or below the softening points of the resin and the dispersion medium, dissolving and removing the dispersion medium, and locating a plasticizer on the surfaces of the resulting resin coated conductive particles. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a circuit pattern forming toner used for forming a circuit pattern on a printed wiring board, a method for producing the same by a phase separation method using a non-aqueous emulsion, and a process for forming a toner image by a two-component development method. The circuit pattern formation method containing this.

  A color filter or a printed wiring board used for various displays is produced by forming a circuit pattern (conductor) on a green sheet made of glass ceramic. As the formation method, a paste containing a colorant composed of metal particles such as silver or copper or metal oxide particles such as ruthenium oxide and a binder resin is applied to the substrate by, for example, screen printing or lithographic offset printing, and 500 to By baking at a temperature of 600 ° C., it has been conventionally performed to fix the colorant by disappearance of the binder resin and melting of the low melting point glass. However, in the screen printing method, it is not possible to form a fine circuit pattern for reasons such as screen dripping or spreading of the paste during printing, and therefore it has been proposed to form a circuit pattern by electrophotography.

For example, in Patent Document 1, a photoconductor having an organic photoconductive layer is formed on a substrate, an electrostatic latent image is formed on the surface of the photoconductor, and a binder resin, conductive particles, and a charge control agent are melted and kneaded. The electrostatic latent image is developed with toner prepared by pulverization after cooling, the substrate is baked to remove the binder in the toner and the photoreceptor, and then baked at a high temperature to form the wiring pattern on the substrate. It is described that it sticks. In Patent Document 2, the surfaces of metal particles or metal oxide particles are coated with an insulating resin layer obtained by a monomer direct polymerization method, and a charge imparting layer is provided around or inside the insulating resin layer. It is described that a toner image is formed by electrophotography using a metal toner, and the toner image is transferred to a ceramic thin film sheet and then heated to form a conductor pattern. In Patent Document 3, as a method for producing a toner having a core / shell structure for forming a circuit pattern on a ceramic sheet, a dispersion in which resin particles and metal particles are dispersed is salted out or ph-adjusted. In addition, it is described that composite particles having resin particles attached to the surface of metal particles are prepared, the composite particles are heated to a temperature near the glass transition point of the resin particles, and then dried and smoothed. In Patent Document 4, as a method for producing a spherical composite powder composed of thermoplastic resin particles encapsulating a filler, a resin composition composed of a thermoplastic resin and a filler is mixed with a dispersion medium incompatible with the resin composition. A method (phase separation method using a non-aqueous emulsion) is described in which a fine particle is heated and mixed to a temperature equal to or higher than the melting point and dispersed into fine particles, and the obtained fine particles are cooled to a temperature equal to or lower than the melting point. It is also described that it can be used for machine toners. Patent Document 5 includes a metal core particle and a polymer coating layer that coats the outer surface thereof. The metal core particle is treated with a mercapto compound (a compound that forms a complex with a metal). The coated metal fine particles obtained by mixing with the molecular compound are externally or internally added with a charge control agent, a fluidizing agent, etc. as necessary, and heated after fixing to remove the polymer compound from the toner. A toner is described in which a glass component is provided in order to enhance the adherence of the metal component to ceramics later.
Japanese Patent No. 3147621 (page 3-5) Japanese Patent No. 3232280 (pages 3-4 and 13) JP 2001-5217 A (page 2-4) JP 2001-114901 A (page 2-4) Japanese Patent No. 3418555 (pages 3-7)

  In the pattern forming method described in Patent Document 1, since the toner prepared by the kneading and pulverization method is used, the fracture surface of the particles pulverized when the kneaded material containing the resin and metal particles is cooled and solidified and then pulverized. In addition, since the metal particles are easily exposed and the metal particles are present on the surface of the toner, there is a problem that the insulating property of the toner is lowered and a fine circuit pattern cannot be formed. The metal toner described in Patent Document 2 has a high electric insulation withstand voltage because the surface of the metal particles is covered with an insulating resin. However, since the insulating resin layer is formed by the direct polymerization method of the monomer, the charging particles cannot be taken into the insulating resin layer at the time of polymerization, and the charging particles are added to the surface of the composite resin particles. Is mixed. When the charge imparting layer is formed by the mechanical surface treatment method as described above, there is a problem that variation in charging characteristics easily occurs between individual particles. According to the method described in Patent Document 3, it is possible to incorporate a charge control substance into the resin layer covering the surface of the metal particles, but the resin particles include monomers, a polymerization initiator, a charge control agent, and an interface. Since it is prepared by emulsion polymerization reaction by mixing an activator, there is a problem that the chargeability is lowered due to the influence of the surfactant remaining after the polymerization reaction, and the chargeability is deteriorated particularly under environmental conditions of high humidity. The composite powder described in Patent Document 4 does not contain a chargeable substance in the thermoplastic resin encapsulating the filler, so that the image density of the toner image is low and cannot be put to practical use. In the toner described in the example of Patent Document 5, a charge control agent is externally added to the polymer coating layer that coats the outer surface of the metal core particle, resulting in variation in charging characteristics between individual toner particles. There is a problem that it is easy.

  When a toner image is formed using the above toner, it can be considered that the toner is mixed with a carrier and developed with a normal magnetic brush developing device (for example, a sleeve rotating type). However, the toner mainly composed of metal particles has a specific gravity. Therefore, there is a problem that when the magnetic brush head is formed by the developing magnetic pole, the toner is scattered in the printer due to the centrifugal force of the sleeve, and the image is contaminated. As a countermeasure, it is conceivable to use a developing device of a type that directly adsorbs and holds toner on the surface of the magnet roll, but in this sleeveless type developing device, the toner once adsorbed on the surface of the magnet roll is present there. There is a problem that the image quality deteriorates as the number of printed sheets increases because the toner stays and the toner is not replaced.

  An object of the present invention is to provide a toner for forming a circuit pattern having a high electric insulation withstand voltage and chargeability.

  Another object of the present invention is to provide a production method capable of obtaining a toner for forming a circuit pattern having a high charge amount and a small variation in charge amount between individual particles.

  Another object of the present invention is to provide a method capable of forming a fine circuit pattern with high accuracy even when a large number of sheets are printed.

  In order to achieve the above object, the circuit pattern forming toner of the present invention has been subjected to a hydrophobic treatment comprising conductive particles made of a metal or an oxide thereof and inorganic oxide particles having a smaller particle size than the conductive particles. The toner particles include a mixed particle and an insulating resin layer covering the surface thereof. The insulating resin layer has an electrical property of being charged to a predetermined polarity, and the toner particles are phase-separated by a non-aqueous emulsion. It is the particle | grains formed by.

  In the toner for forming a circuit pattern of the present invention, the insulating resin layer includes at least one charge control substance selected from a fluorine resin, a silicone resin, a resin having a polar group, a metal complex, an azo compound, and an azine compound. It is preferable to contain.

  In the circuit pattern forming toner of the present invention, the insulating resin layer is preferably mainly composed of a thermoplastic resin having a softening point of less than 130 ° C., and the thermoplastic resin includes an olefin resin and a cellulose resin. More preferably, it is made of a mixed resin.

  In order to achieve the above object, the circuit pattern forming toner of the present invention hydrophobizes mixed particles composed of conductive particles composed of a metal or an oxide thereof and inorganic oxide particles having a smaller particle diameter than the conductive particles. The charge control substance and the insulating resin are added to a dispersion medium that is not compatible with the resin, and heated and kneaded at a temperature below the softening point of the insulating resin and the dispersion medium to dissolve and remove the dispersion medium. It is produced by adding a fluidizing agent to the surface of the resin-coated mixed particles obtained in this way.

  In the method for producing a circuit pattern forming toner of the present invention, the charge control substance is at least one substance selected from a fluorine resin, a silicone resin, a resin having a polar group, a metal complex, an azo compound, and an azine compound. It is preferable to contain.

  In the method for producing a circuit pattern forming toner of the present invention, it is preferable to use an olefin resin and a cellulose resin as the insulating resin.

  In order to achieve the above object, the circuit pattern forming method of the present invention holds the developer comprising the toner and the magnetic carrier on the surface of a non-magnetic belt wound around a magnet roller that rotates in a predetermined direction. The toner image formed on the surface of the image carrier is transferred to a development area formed between the image carrier holding an electrostatic charge image corresponding to the circuit pattern and the non-magnetic belt. The circuit pattern made of a conductor is formed by sintering after transfer.

  In the circuit pattern forming method of the present invention, the toner image is preferably sintered at a temperature of 550 to 650 ° C. for 5 to 30 minutes after being thermally transferred onto the ceramic green sheet.

  According to the toner of the present invention, since the metal particles are imparted with high insulation and chargeability, a fine circuit pattern can be formed on the ceramic substrate by electrophotography.

  According to the method for producing a circuit pattern forming toner of the present invention, the surface of the metal particles is coated with a resin having a property of being charged to a predetermined polarity by a phase separation method with a non-aqueous emulsion. A toner with little variation in the charge amount between the particles can be obtained.

  According to the circuit pattern forming method of the present invention, the developer after passing through the developing region is scraped off from the nonmagnetic belt, mixed with new toner in the developer container, and then adsorbed to the nonmagnetic belt again. Therefore, even when a large number of sheets are printed, a high quality image can be obtained. Further, since the developer is held on a non-magnetic belt wound around a magnet roll and the magnetic brush moves together with the magnetic poles in the development region, the developer is prevented from scattering due to the rise of the magnetic brush, and the image Contamination is prevented.

Embodiments of the present invention will be described below. In the present invention, metal particles such as silver, copper, nickel and tungsten or metal oxide particles such as ruthenium oxide can be used as the conductive particles forming the circuit pattern. The particle diameter (volume average particle diameter) of these particles is preferably in the range of 2 to 10 μm, and the shape of the particles may be either spherical or irregular. When fine particles of 3 μm or less are used as the conductive particles, associated particles (aggregates) in which primary particles are aggregated are used. Further, the surface property does not need to be porous such as sponge, but rather is desirably high density. The above metal particles or metal oxide particles are mixed with inorganic oxide particles and have an affinity for the insulating resin in order to enhance the adhesion of the metal particles to the ceramic after the insulating resin is removed from the toner image. In order to improve the properties, it is desirable to perform a hydrophobization treatment. As the inorganic oxide particles, glass powder (PbO—SiO ₂ —B ₂ O ₃ or the like) having a smaller particle size than the metal particles may be used. If the average particle size of the inorganic oxide particles is too small, the adhesion to the substrate is lowered, and if it is too large, the conductivity after sintering is lowered, so the range of 0.1 to 5 μm is preferable. The mixing ratio of the inorganic oxide particles and the conductive particles is such that if the inorganic oxide particles are too small, the adhesion to the substrate is lowered, and if the inorganic oxide particles are too much, the conductivity after sintering is reduced. The range of 1:99 to 20:80 by mass ratio is preferred. As a method for hydrophobizing mixed particles composed of conductive particles and inorganic oxide particles having a smaller particle diameter, the mixed particles may be dimethyldichlorosilane, hexamethyldisilazane, silicone oil, octylmethoxysilane, linear fatty acid, etc. It is possible to employ a method in which a hydrophobizing agent is mixed with a solution in a solvent (for example, alcohol), heated and dried. Among these hydrophobizing agents, it is preferable to use a compound having a low melting point, for example, a straight-chain fatty acid, particularly oleic acid (melting point: 13.4 ° C) is preferred.

As the insulating resin for covering the conductive particles (volume resistivity is 10 ¹² Ω · cm or more), various thermoplastic resins or condensed resins can be used. It is preferably a thermoplastic resin having a softening point of less than 130 ° C., particularly a softening point of 120 ° C. or less, so that it can be easily thermally decomposed in the setting step and removed from the surface of the metal particles in a short time. It is more preferable that the thermoplastic resin has. The softening point of the resin was determined by using a Koka flow tester (CFT-500, manufactured by Shimadzu Corporation) from a die with a hole diameter of 1 mm and a length of 10 mm, a pressure of 30 kg / cm ^{2 and} a heating rate of 3 ° C./min. Measured as a temperature corresponding to an intermediate point between the outflow start point and the outflow end point when a 1 cm ³ sample was discharged. Examples of the resin having such a low softening point include a cellulose resin. The cellulose resin is a resin produced by blending an additive such as a plasticizer with a derivative (main raw material) obtained by chemically esterifying or etherifying cellulose. Examples of the cellulose derivative include cellulose esters such as nitrocellulose, acetyl cellulose, cellulose acetate butyrate, and cellulose acetate propionate, and cellulose ethers such as ethyl cellulose.

  Cellulosic resins are generally easy to ignite and difficult to handle, so it is preferable to use them mixed with a thermoplastic resin having a relatively low softening point. Specific examples of the thermoplastic resin include olefin-based resins typified by polyethylene. Low-density polyethylene (softening point (measured by ASTM D1525, the same applies below): 85 to 95 ° C.), medium-density polyethylene, And high-density polyethylene (softening point: 115 to 125 ° C.). The mixing ratio of the low softening point thermoplastic resin and the nitrocellulose resin can be selected in the range of 1: 9 to 9: 1 by weight.

  Examples of the condensation resin that can be used in the present invention include polyester resins and epoxy resins that are polycondensates of polyhydric alcohols and polybasic acids (with a molecular weight of about 300 to 8000 having two or more epoxy groups in one molecule). Prepolymers), polyamide resins that are linear polymers with an amide bond in the main chain, phenol resins obtained by addition polymerization of phenols and formaldehyde, urethane resins synthesized by polyaddition that does not generate water molecules, etc. In the present invention, these resins can be used alone or in admixture of two or more. Of these resins, unsaturated polyester resins which are polycondensates of unsaturated fatty acids, dibasic acids, glycols and vinyl monomers are particularly preferred from the viewpoint of image quality, and ring-opening polymerization of cyclic lactams or aminocarboxylic acids. Nylon n obtained by polycondensation reaction and nylon nm obtained by polycondensation reaction of linear diamine and linear dicarboxylic acid or salt thereof can also be used effectively.

  The coating thickness of the insulating resin is preferably in the range of 0.2 to 1 μm. If the coating thickness of the insulating resin is less than 0.2 μm, the metal particles are exposed on the surface and the chargeability is lowered. If the coating thickness of the resin exceeds 1 μm, the sintering step after the formation of the toner image Therefore, it is difficult to thermally decompose (disappear), and it remains on the surface of the metal particles, which increases the resistance of the circuit pattern, which is disadvantageous. In order to obtain such a coating thickness, the metal powder is preferably mixed with 5 to 30 parts by mass of resin per 100 parts by mass of the metal powder.

  In the present invention, in order to impart appropriate chargeability to the toner, the insulating resin that coats the metal particles or metal oxide particles has a polar group such as a hydroxyl group or an amino group, and is positive or negative. It is preferable that the resin be easily charged easily or a resin to which a charge control substance imparting positive or negative charge is added. Examples of positive charge control substances include nigrosine bases and derivatives thereof, quaternary ammonium salts, naphthenic acid or higher fatty acid salts, alkoxylated amines, alkylamides, triphenylmethane dyes, and these positive polarity substances in the side chain. Oligomers or polymers, quaternary pyridinium, and higher fatty acid metal salts may be used. As the negative charge control substance, a metal-containing (Cr or Fe) azo complex dye or a chromium / zinc / aluminum / boron complex of salicylic acid or a derivative thereof may be used. However, these charge control substances have a difference in solubility between the coating resin and the dispersion medium, and it is desirable to use a material having a high solubility in the insulating resin or a material having a high affinity when dispersed in the resin. The content of the charge control substance is preferably in the range of 0.5 to 2 parts by mass per 10 parts by mass of the insulating resin. When the content of the charge control substance is less than 0.5 parts by mass, the charge amount is insufficient. On the other hand, when the content exceeds 2 parts by mass, the ground fog increases.

  The insulating resin can contain, for example, a colorant, if necessary, together with the charge control substance. As the colorant, known inorganic pigments, organic pigments or dyes can be used. Red colorant is cadmium red, cadmium mercury red, yellow colorant is chrome yellow, ceramic yellow, green colorant is chrome green, phthalocyanine green, blue colorant is ultramarine blue, phthalocyanine blue, etc. Can be mentioned. These colorants are preferably selected in consideration of compatibility with the resin.

  In addition, in order to impart fluidity of the toner, the surface of the toner particles is subjected to a hydrophobic treatment with a fluidizing agent, for example, a coupling agent such as a silane coupling agent or a titanate coupling agent, or silicone oil. (Silica, titania, alumina, etc.) is preferably added. The amount added is preferably in the range of 0.3 to 1 part by mass per 100 parts by mass of toner particles. If the amount added is less than 0.3 parts by mass, there is no effect. On the other hand, if the content exceeds 1 part by mass, the toner particles are easily detached from the surface, and the image is stained.

  The production method of the present invention includes a first step of hydrophobizing mixed particles composed of conductive particles composed of metal or metal oxide and inorganic oxide particles having a smaller particle size than the conductive particles; The mixed particles, the charge control substance, and the insulating resin are added to a dispersion medium that is not compatible with the resin, and heated and kneaded at a temperature below the softening point of the resin and the dispersion medium to dissolve and remove the dispersion medium. It is roughly divided into a second step and a third step of adding a fluidizing agent to the surface of the resin-coated mixed particles.

  After preparing the mixture of the mixed particles obtained in the first step, the insulating resin containing the charge control substance, and the dispersion medium incompatible with the resin, the second step is performed. That is, the mixture is kneaded with a kneader or a mixer while being heated at a temperature lower than the softening point of the resin, so that the mixed particles are dispersed in the resin and the surface of the mixed particles is coated with the resin. When the heating temperature of the above mixture is low, it is not dispersed in the fine particles, and when it is high, the resin is likely to be thermally decomposed. The kneaded product is put into hot water and stirred to dissolve the dispersion medium, and then the resin-coated metal particles are separated by, for example, a centrifuge. Next, the resin-coated metal particles are washed (for example, washed with water and alcohol), dried, and then added with a fluidizing agent to the surface of the particles, so that the metal particles are coated with a thermoplastic resin and charge control is performed in the coating resin. Toner particles made of metal particles to which a functional substance is added are produced.

  As described above, toner particles are prepared by a phase separation method using a non-aqueous emulsion, whereby an additive (for example, a charge control substance) is uniformly dispersed in the insulating resin. Phase separation is defined as the separation of a homogeneous mixture of two or more components into two or more phases according to equilibrium conditions (temperature, pressure, concentration, etc.). The phase separation is performed after dispersing the hydrophobic particles of the mixed particles and the charge control substance-containing resin composed of the conductive particles and the inorganic oxide particles smaller than the conductive particles in a solvent other than water. Then, toner particles are obtained by a phase separation method using a non-aqueous emulsion.

When the phase separation method using the non-aqueous emulsion is performed, it is preferable to use a solvent that does not substantially swell or dissolve the resin as the dispersion medium that is not compatible with the thermoplastic resin. That is, a solvent having an SP value far from the solubility parameter {SP value (MJ / m ³ ) ^1/2 } of the resin may be selected. Specific examples of the solvent include polyethylene oxide, ethylene glycol (SP value: 29.1), propylene glycol, and polyvinyl alcohol. In order to make it easy to dissolve and remove the dispersion medium, among these solvents, those having a low softening point (130 ° C. or lower), such as polyethylene glycol (ethylene glycol polymer or ethylene oxide polymer) at both ends. A compound having a hydroxyl group is preferred. Polyethylene glycol is water-soluble and has a function of reducing the melting temperature or viscosity of the resin, so that it can be used effectively in the present invention. The SP value of the resin is, for example, polystyrene: 18.7 (theoretical value, the same applies hereinafter), polypropylene 16.6, epoxy: about 22.5, polyamide (nylon 66): 27.8, PTFE: 12.7 Nitrocellulose: 21.4. In addition, said each SP value is a value described in "Oishi: Durability of polymer material, p. 74, Industrial Research Committee (1993)". The amount of the solvent used is preferably in the range of 120 to 200 parts by mass with respect to 100 parts by mass of the resin.

The toner particles of the present invention desirably have a volume average particle size in the range of 2 to 10 μm. If the average particle size is less than 2 μm, the amount of ground fog increases, and if the average particle size exceeds 10 μm, a fine image cannot be obtained. The preferred particle size range is 4-8 μm. The average particle size is a value calculated from a particle size distribution measured with a Coulter Multisizer (manufactured by Coulter Counter). In order to obtain a clear toner image, the toner particles have a volume resistivity of 10 ¹⁴ Ωcm or higher when measured in a parallel plate cell with a DC 1,000 V / cm electric field. In addition, it is preferable that the baked toner image has conductivity so as to have a volume resistivity of 10 ⁶ Ωcm or less in order to form an electric circuit. Furthermore, the toner particles preferably have a triboelectric charge amount in the range of 10 to 30 μc / g in absolute value in order to obtain a clear image. This triboelectric charge is obtained by mixing toner with a ferrite carrier (average particle size 100 μm, Cu—Zn ferrite) (toner concentration 5 mass%), vibrating in a container and triboelectrically charged, and then commercially available blow-off powder. It is a value measured by a charge amount measuring device (TB-500 manufactured by Toshiba Chemical Corporation).

In the present invention, a circuit pattern can be formed, for example, according to the following steps using the above toner. The electrostatic charge image formed by uniformly charging the surface of the photoreceptor after exposure (writing a circuit pattern) is developed using the above toner, thereby forming a toner image. The toner of the present invention is nonmagnetic and has a large specific gravity. Specifically, the toner has a bulk density in the range of 1.5 to ³ × 10 ³ kg / m ³ , and a resin and a colorant (pigment) are used. The value is three times or more that of normal toner as a main component. When such a nonmagnetic toner having a large specific gravity is mixed with a magnetic carrier and an electrostatic charge image is developed by a magnetic brush developing method, it is preferable to form an image with a two-component developing device having the structure shown in FIG. In FIG. 1, a developing device 2 is disposed around a photosensitive member (for example, an OPC drum) 1 that rotates in a clockwise direction indicated by an arrow. The developing device 2 includes a developer container 21 that stores a developer 20 composed of toner and a magnetic carrier, a developing roller 22 that is provided in contact with or close to the surface of the photoreceptor 1, and is connected to a bias voltage source 23. A regulating blade 24 that forms a thin layer of toner in the vicinity of the surface of the developing roller 22 and a stirring roller 25 that mixes the developer scraped off from the developing roller 22 with new toner. The developing roller 22 has a pair of magnet rollers 26 and 27 having a plurality of magnetic poles on the surface and a nonmagnetic belt 28 wound around the outer peripheral surface thereof, and the nonmagnetic belt 28 is counterclockwise indicated by an arrow in the figure. One magnet roller 27 is connected to a drive source (not shown) such as a motor. It is also possible to use a metal pulley instead of the magnet roller 27. The nonmagnetic belt is formed of, for example, an endless thin plate having flexibility and made of a nonmagnetic material.

  According to the developing device 2, the developer 20 that has been mixed by the stirring roller 25 and then supplied to the surface of the developing roller 22 has a doctor gap dg formed between the regulating blade 24 and the surface of the nonmagnetic belt 28. By passing through, it is regulated to a predetermined thickness and conveyed to the development area. Next, an electrostatic charge image (not shown) formed on the surface of the photoreceptor 1 is developed by a charging means and an exposure means (both not shown) to form a toner image. The developer adsorbed on the surface of the nonmagnetic belt 28 passes through the development gap Dg, then falls from the nonmagnetic belt 28 between the magnet rollers 26 and 27, and is mixed with the toner in the developer container 21 by the stirring roller 25. After mixing, the toner is supplied to the surface of the developing roller 22 and the same process is repeated again. By performing image formation by the two-component development method as described above, the developer passes through the development gap Dg together with the magnetic pole while being held on the surface of the non-magnetic belt 28, so that the magnetic brush does not rise and the magnetic It is possible to prevent the developer from being scattered by the centrifugal force when the brush rises. Moreover, the developer that has passed through the development gap Dg is once scraped off from the nonmagnetic belt 28 and then adsorbed on the surface of the nonmagnetic belt 28 again. A high quality image can be maintained even if it goes.

  By transferring the above toner image onto a ceramic substrate (green sheet) and sintering at a temperature equal to or higher than the decomposition temperature of the insulating resin after fixing, the insulating resin is removed from the toner image (by debinding), A circuit pattern made of a conductor is formed on the ceramic substrate. For the transfer of the toner image, a known method such as electrostatic transfer or pressure transfer using a roller can be used. In particular, thermal transfer enables easy transfer onto a ceramic substrate. In order to remove the insulating resin covering the conductive particles, the sintering temperature is preferably set in the range of 550 to 650 ° C., and the sintering time is preferably 30 minutes or less from the viewpoint of productivity.

  The conductivity of the circuit pattern formed on the ceramic substrate as described above is evaluated by printing a solid black image on the substrate and measuring the resistance value by a four-terminal method after heat treatment. The adhesion between the circuit pattern and the ceramic substrate is evaluated by conducting a cross-cut tape peeling test on the functional surface of the circuit pattern sample in accordance with JIS D 0202-1988. In the present invention, the cellophane tape “CT-24” manufactured by Nichiban Co., Ltd. is adhered to the functional surface of the sample with the belly of the finger and then peeled off. When the eye / total square is 100/100, the adhesiveness is good, and 90-95 / 100 is judged as the poor adhesiveness.

  The present invention will be described in further detail with reference to the following examples and comparative examples. In the following description, “part” means “part by mass”.

To 100 parts of copper powder having an average particle diameter of 9 μm and 20 parts of glass powder having an average particle diameter of 1 μm (mainly composed of SiO ₂ , Al ₂ O ₃ , ZnO, SnO _2, etc.), a silane coupling agent (Tore 10 parts of a solution obtained by dissolving Dow Corning Silicone SZ6083) in isopropyl alcohol was added and mixed, followed by heat treatment at 100 ° C. for 2 hours. The obtained hydrophobic mixed powder, 25 parts of styrene-acrylic copolymer (CPR600, Mitsui Chemicals, softening temperature: 135 ° C.) and 5 parts of negative charge control agent (Bontron S34, Orient Chemical Co., Ltd.) were mixed with a high speed mixer ( The mixture was mixed by a Henschel mixer and kneaded at 130 ° C. (set temperature) at a rotation speed of 100 rpm by a twin-screw kneading extruder (TEX30 manufactured by Nippon Steel). To the obtained pellets, 100 parts of polyethylene oxide (softening temperature: 145 ° C.) was added as a dispersion medium, and the mixture was kneaded again at 130 ° C. at a rotation speed of 100 rpm with a twin-screw kneading extruder (TEX30 manufactured by Nippon Steel). When the cross section of the kneaded material was observed with an electron microscope, it was confirmed that the metal particles (copper powder) were coated with a resin. The dispersion medium was dissolved while stirring the heated kneaded product in hot water, and then the resin-coated mixed particles were separated using a centrifuge. The resin-coated mixed particles were washed with water and then with alcohol, and then dried for 12 hours at a temperature of 70 ° C. using a vacuum dryer. To the obtained powder, 1 part of hydrophobic silica powder (H3004, manufactured by Wacker) was added and mixed with a high speed mixer to prepare a toner having a volume average particle diameter of 11 μm. The obtained toner was not agglomerated, and there were almost no resin particles (empty balls). The toner has a volume resistivity of 2.5 × 10 ¹⁴ Ω · cm under a direct current electric field of 1,000 V / cm, and it was confirmed that the toner exhibits insulating properties. Further, as a result of measuring the triboelectric charge amount of the toner by the blow-off method, it was confirmed to show −32 μc / g.

  A developing device 2 shown in FIG. 1 is provided around an OPC drum (negatively charged organic photoconductor) 1 having a diameter of 40 mm to form a printing device in which the process speed is set to 200 mm / sec. And a magnetite carrier (average particle size: 60 μm) were supplied so that the toner concentration was 6 mass%, and an image corresponding to the circuit pattern was created in an environment of 20 ° C. and 60% RH. . The image creation conditions are as follows. In the developing device 2, a non-magnetic belt 28 made of austenitic stainless steel (SUS304) is wound around a magnet roller 26 (a cylindrical magnet having an outer diameter of 30 mm is magnetized symmetrically with 10 poles and the surface magnetic flux density is 800 G). The development gap Dg is set to 0.8 mm, the doctor gap dg is set to 0.5 mm, the OPC drum 1 and the nonmagnetic belt 28 move in the same direction in the development gap, and the circumferential speed ratio becomes 2. Thus, the magnet roller 27 was driven. The surface of the OPC drum 1 is uniformly charged by corona charging and then exposed by an LED array to form an electrostatic charge image (surface potential: -480V), and a reverse bias development is performed by applying a DC bias voltage of -400V to the developing roller 2. By doing so, a toner image was formed. After this toner image was roller transferred onto a ceramic green sheet having a thickness of 0.1 mm, the sheet was oven-fixed at 200 ° C. As a result, a clear toner image having a toner thickness of 40 to 70 μm and no fogging or dusting was obtained. Obtained. This green sheet was sintered in a nitrogen gas atmosphere at a temperature of 600 ° C. for 30 minutes to perform a binder removal treatment. As a result, a circuit pattern showing sufficient conductivity and good adhesion to the substrate was obtained. Furthermore, it was confirmed that a high-quality image without ground fog or image defect was obtained even after printing 5000 sheets under the same conditions as described above. Further, in the above development process, it was confirmed that the scattering of the developer was at a level having no practical problem.

To 100 parts of flaky nickel powder having an average particle size of 5 μm and 20 parts of glass powder similar to Example 1, 10 parts of a solution in which a titanate coupling agent (plain act TTS manufactured by Ajinomoto Co., Inc.) was dissolved in isopropyl alcohol was added and mixed. After the treatment, heat treatment was performed at a temperature of 100 ° C. for 2 hours. Example 1 1 part of the obtained hydrophobic mixed powder, 25 parts of polyamide resin (nylon-12), 5 parts of a positive charge control agent (FCA201PS manufactured by Fujikura Kasei Co., Ltd.) and 5 parts of a positive charge control agent (Bontron No. 4 manufactured by Orient Chemical Co., Ltd.) Were mixed and kneaded under the same conditions. 50 parts of polyethylene oxide (softening temperature: 145 ° C.) was added using the obtained pellets as a dispersion medium, and kneaded again under the same conditions as in Example 1. When the cross section of the kneaded material was observed with an electron microscope, it was confirmed that the metal particles (nickel powder) were coated with a resin. After the heat-kneaded material was treated in the same manner as in Example 1, 0.6 parts of hydrophobic silica powder (TG802CF, manufactured by Cabot) was added to the obtained powder and mixed with a high-speed mixer to obtain a volume average particle size. A toner having a diameter of 7 μm was prepared. The obtained toner particles were uniformly coated with a resin and had an irregular shape. The toner has a volume resistivity of 3 × 10 ¹⁴ Ω · cm under a direct current electric field of 1,000 V / cm, and it was confirmed that the toner exhibits insulating properties. As a result of measuring the triboelectric charge amount of the toner by the blow-off method, it was confirmed to show +23 μc / g.

  A developing device 2 shown in FIG. 1 is provided around an OPC drum (positively charged organic photoconductor) 1 having a diameter of 32 mm to form a printing device in which the process speed is set to 150 mm / sec. An image corresponding to a circuit pattern in an environment of 20 ° C. and 60% RH is supplied by supplying a developer in which the toner concentration is 8% by mass with Mn—Zn ferrite carrier (average particle size is 35 μm). It was created. The image creation conditions are as follows. The developing device 2 rotates the magnet roller 27 so that the OPC drum 1 and the nonmagnetic belt 28 move in the opposite directions and the peripheral speed ratio becomes 2 in the developing gap, and the regulating blade is installed on the downstream side of the developing gap. The configuration was the same as in Example 1 except that. The surface of the OPC drum 1 is uniformly charged by corona charging and then exposed by an LED array to form an electrostatic charge image (surface potential: +500 V), and a reverse bias development is performed by applying a DC bias voltage of +400 V to the developing roller 2. Thus, a toner image was formed. After this toner image was roller transferred onto a ceramic green sheet having a thickness of 0.1 mm, the sheet was oven-fixed at 200 ° C. As a result, a clear toner image having a toner thickness of 40 to 70 μm and no fogging or dusting was obtained. Obtained. This green sheet was sintered in a nitrogen gas atmosphere at a temperature of 600 ° C. for 30 minutes to perform a binder removal treatment. As a result, a circuit pattern showing sufficient conductivity and good adhesion to the substrate was obtained. Furthermore, it was confirmed that a high-quality image without ground fog or image defect was obtained even after printing 5000 sheets under the same conditions as described above. Further, in the above development process, it was confirmed that the scattering of the developer was at a level having no practical problem.

100 parts of silver powder having an average particle diameter of 7 μm and 20 parts of glass powder having an average particle diameter of 0.3 μm and the same composition as in Example 1 were mixed with 10 parts of a solution of oleic acid dissolved in isopropyl alcohol. Then, heat treatment was performed at a temperature of 100 ° C. for 2 hours. This hydrophobic mixed powder, polyethylene wax (wax 200PF, Mitsui Chemicals, softening point: 120 ° C.) 10 parts, thermal decomposable resin (nitrocellulose resin) 10 parts, negative charge control agent (Orient Chemical Co., Ltd. Bontron E89) One part was mixed with a high speed mixer (Henschel mixer) and kneaded in the same manner as in Example 1. 100 parts of polyethylene glycol (softening point: 125 ° C.) as a dispersion medium was added to the obtained pellets, and the mixture was kneaded again at 130 ° C. at a rotation speed of 100 rpm by a biaxial kneading extruder. The dispersion medium was dissolved while stirring the kneaded product in hot water, and then the resin-coated mixed particles were separated using a centrifuge. The resin-coated mixed particles were washed with water and methanol, and then dried at a temperature of 70 ° C. for 12 hours using a vacuum dryer. To the obtained powder, 1 part of hydrophobic silica powder (RX300, manufactured by Degussa) was added and mixed with a high speed mixer to prepare toner particles having a volume average particle diameter of 9.5 μm. All the toner particles were uniformly coated with a resin and had an indefinite shape. The toner had a volume resistivity of 1 × 10 ¹⁴ Ω · cm and an insulating property, and the charge amount was −35 μc / g.

A developing device 2 shown in FIG. 1 is provided around an OPC drum (negatively charged organic photoconductor) 1 having a diameter of 40 mm to form a printing device in which the process speed is set to 200 mm / sec. And a magnetite carrier (average particle size: 60 μm) were mixed so that the toner concentration was 6% by mass, and an image corresponding to the circuit pattern was created under environmental conditions of 20 ° C. and 60% RH. . The image creation conditions are as follows. In the developing device 2, a non-magnetic belt 28 made of austenitic stainless steel (SUS304) is wound around a magnet roller 26 (a cylindrical magnet having an outer diameter of 30 mm is magnetized with 10 symmetrical poles and a surface magnetic flux density is 800 G). The developing gap Dg is set to 0.8 mm, the doctor gap dg is set to 0.5 mm, the OPC drum 1 and the nonmagnetic belt 28 move in the same direction in the developing gap, and the peripheral speed ratio becomes 2. Thus, the magnet roller 27 was driven. The surface of the OPC drum 1 is uniformly charged by corona charging and then exposed by an LED array to form an electrostatic charge image (surface potential: -480V), and a reverse bias development is performed by applying a DC bias voltage of -400V to the developing roller 2. By doing so, a toner image was formed. After this toner image was roller transferred onto a ceramic green sheet having a thickness of 0.1 mm, the sheet was oven-fixed at 200 ° C. As a result, a clear toner image having a toner thickness of 40 to 70 μm and no fogging or dusting was obtained. Obtained. This green sheet was sintered at a temperature of 600 ° C. for 10 minutes to perform a binder removal treatment. As a result, a circuit pattern showing sufficient conductivity and good adhesion to the substrate was obtained. Furthermore, it was confirmed that a high-quality image free from ground fog and image defects can be obtained even after printing 5000 sheets under the same conditions as described above. Further, in the above development process, it was confirmed that the scattering of the developer was at a level having no practical problem.
(Comparative Example 1)

A toner was prepared under the same conditions as in Example 1 except that the copper powder and glass powder were not hydrophobized, and a toner image was formed under the same conditions as in Example 1. This toner had a low volume resistivity of 10 ⁹ Ω · cm, and the obtained toner image was an image with much ground fog.
(Comparative Example 2)

Using the developer of Example 1, a developing device is used in which a magnet roll is fixed so that one magnetic pole (for example, N pole) is positioned on the developing cap, and a nonmagnetic sleeve having a diameter of 32 mm is arranged around the sleeve. A toner image was formed under the same conditions as in Example 1 except that was rotated counterclockwise so that the peripheral speed ratio was 2. It was confirmed that the developer was scattered to cause image smearing and in-machine contamination.
(Comparative Example 3)

  The same as Example 1 except that 5 parts of glass powder having an average particle size of 3 μm was added to the powder obtained by washing, washing and drying the resin-coated mixed particles not containing glass powder and stirred with a high-speed mixer. The toner was prepared under the conditions described above, and a toner image was formed under the same conditions as in Example 1. Since this toner was externally added with glass powder, the chargeability was lowered, and the obtained toner image was an image with a lot of ground fog at high humidity.

It is sectional drawing which shows an example of the image development apparatus used by this invention.

Explanation of symbols

1: Photosensitive member 2: Developing device 21: Developer container 22: Developing roller 23: Bias voltage source 24: Restricting blade 25: Stirring roller 26: Magnet roller 27: Magnet roller 28: Nonmagnetic belt

Claims (9)

From toner particles comprising conductive particles made of metal or metal oxide, inorganic oxide particles having a smaller particle diameter than the conductive particles, hydrophobized mixed particles, and an insulating resin layer covering the surface thereof Thus, the insulating resin layer has an electrical property of being charged to a predetermined polarity, and the toner particles are particles formed by a phase separation method using a non-aqueous emulsion. The insulating resin layer includes one or more charge control substances selected from a fluorine resin, a silicone resin, a resin having a polar group, a metal complex, an azo compound, and an azine compound. Item 2. The toner for forming a circuit pattern according to Item 1. 3. The circuit pattern forming toner according to claim 1, wherein the insulating resin layer is mainly composed of a thermoplastic resin having a softening point of less than 130 ° C. 4. 4. The circuit pattern forming toner according to claim 3, wherein the thermoplastic resin is made of a mixed resin of an olefin resin and a cellulose resin. The mixed particles made of conductive particles made of metal or oxide thereof and inorganic oxide particles having a smaller particle size than the conductive particles are subjected to a hydrophobic treatment, and the charge control substance and the insulating resin are compatible with the resin. Adding a fluidizing agent to the surface of the resin-coated mixed particles obtained by dissolving and removing the dispersion medium by heating and kneading at a temperature below the softening point of the resin and the dispersion medium. A method for producing a circuit pattern forming toner. 5. The charge control substance is composed of one or more substances selected from a fluorine resin, a silicone resin, a resin having a polar group, a metal vinegar, an azo compound, and an azine compound. A method for producing the toner for forming a circuit pattern as described. 7. The method for producing a circuit pattern forming toner according to claim 5, wherein the insulating resin comprises an olefin resin and a cellulose resin. A developer containing the toner and magnetic carrier according to any one of claims 1 to 4 is held on a surface of a non-magnetic belt wound around a magnet roller that rotates in a predetermined direction, and a static corresponding to a predetermined circuit pattern. The toner image formed on the surface of the image carrier is transferred to a ceramic green sheet and sintered after being transferred to a developing region formed between the image carrier holding the charge image and the non-magnetic belt. A circuit pattern forming method. 9. The circuit pattern forming method according to claim 8, wherein the toner image is sintered on the ceramic green sheet and then sintered at a temperature of 550 to 650 [deg.] C. for 5 to 30 minutes.

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