JP2003270846A - Metal toner for formation of conductive pattern, carrier, and developer comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer for formation of a conductive pattern having a high rising property for electrification, a high electrification level and excellent image characteristics by improving the electrifying property of a metal toner and combining the toner with a carrier which can impart the electrifying property required for the metal toner. <P>SOLUTION: The metal toner having ≥90% metal purity and 0.2 to 15 μm average particle size is obtained by using a saturated fatty acid, an unsaturated fatty acid and if necessary, a surfactant as a surface treating agent and externally adding the above surface treating agent by 0.1 to 1 wt.% to the surface of core metal particles manufactured by a wet method to form a thin film layer on the particles. The carrier is obtained by coating magnetic particles with a fluorocarbon resin or the like by 0.1 to 3 wt.%. The metal toner and the carrier are combined to obtain the developer for formation of a conductive pattern having 3 to 30 μC/g charge amount of the metal toner. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal toner for forming a conductor pattern by electrophotography, a carrier, and a two-component developer containing the same.

[0002]

2. Description of the Related Art Conventionally, in forming a conductor pattern such as an internal electrode in a laminated electronic component such as a laminated ceramic capacitor, palladium, silver, or a silver powder is formed on a thin green sheet made of ceramic powder such as silica or alumina and an organic binder. A conductive pattern is formed by applying a paste of metal particles such as copper and tungsten in a predetermined pattern by a screen printing method and baking the paste. However, in this screen printing method, a screen composed of a mesh-like net is used.
Material loss to make a screen for each pattern,
Furthermore, there are many problems such as loss of material adhering to the mesh.

In order to solve various problems in such a screen printing method, JP-A-59-189617, JP-A-59-202682, and JP-A-60-1.
No. 37886, JP-A-60-160690, etc., a conductor of metal particles is obtained by electrophotography without the need for a paste unlike the screen printing method, and without using a screen or the like requiring replacement. It is described to form a pattern and fire it.

For example, in the invention of Japanese Patent Laid-Open No. 189617/1984, which relates to a method of manufacturing a multilayer capacitor, palladium powder is used as the charged particles forming the conductor layer,
This is kneaded with polystyrene (binder) and chlorinated polyester (charge control agent), finely pulverized, and then spheroidized to obtain a toner having an average particle size of 10 to 20 μm, and the toner is mixed with a carrier to prepare a two-component system. A predetermined electrode pattern is formed by electrophotography using a developer. But,
Since the toner in these methods has a low resistance value and electric charges are likely to leak, problems remain in terms of highly accurate pattern reproduction in electrophotography and formation of a reliable conductive path.

Further, in order to deal with the above problems, copper,
An electrophotographic method using a metal toner made of tungsten, nickel, silver or the like is disclosed in Japanese Patent Laid-Open No. 2000-98655.
JP-A 2000-106032 and JP-A 2000-2000.
No. 221780. Among these, Japanese Patent Application Laid-Open No. 2000-2000 is related to the metal toner for forming the conductor pattern
Japanese Unexamined Patent Publication (Kokai) No. 98655 discloses a charging property imparting technique in which the surface of metal particles or metal oxide particles is coated with an insulating resin or an insulating resin which is easily charged by using a mechanical surface treatment method. No. 106032 discloses that the surface of metal particles or metal oxide particles is covered with an insulating resin layer obtained by a direct polymerization method of a monomer, and a charging material composed of a charging material is provided around or inside the insulating resin layer. A technique for providing a property imparting layer is described.

On the other hand, a magnetic carrier having a high charging ability and a high density image forming ability is disclosed in, for example, Japanese Patent Laid-Open No. 8-4.
Japanese Patent No. 4118 describes a magnetic core particle made of a ferromagnetic metal such as a ferromagnetic oxide, a ferrite that is a composite thereof, or an iron powder, and coated with a thermosetting resin.

[0007]

When an electrophotographic method using a two-component developer is applied to a circuit forming technique using a conductor pattern whose main purpose is conductivity, a desired charge amount is quickly imparted to a metal powder toner. It is considered necessary that the rising property is good. However, when only metal powder is treated as a toner to enhance conductivity, the metal particles have a low resistance value and a charge leak occurs, and the charge rising property is poor and the charge retention property is poor. There is a problem that a circuit cannot be formed by.

In order to deal with this problem, as disclosed in the above-mentioned respective publications which describe the use of metal powder toner, there is a technique of coating the metal powder toner with a resin so as to have a resistance value. Although proposed, in this conventional technique, the resin coating layer for imparting a desired charging property is becoming thicker by selecting the coating resin, which deteriorates the fluidity of the toner and also during fixing after pattern formation. However, there is a problem in that the coating resin layer serves as an insulating material and deteriorates the conductive performance and adhesion of the circuit.

Furthermore, the above-mentioned Japanese Patent Laid-Open No. 8-44118.
The toner to be combined with the resin-coated carrier described in Japanese Patent Publication No. JP-A No. 2003-242242 is a resin obtained by surface-treating particles obtained by kneading and pulverizing and classifying mainly a fixing resin with carbon black, a release agent, etc. Although toner is used, its suitability for the combination of resin-coated carrier and metal toner is not clear.

In view of the above situation, the present invention provides a metal toner having a thin film surface layer to improve its chargeability and to combine a carrier for imparting necessary chargeability to this metal toner. It is an object of the present invention to provide a metal toner for forming a conductor pattern, a carrier, and a developer comprising these, which have good properties, high charge level, and excellent image characteristics.

[0011]

DISCLOSURE OF THE INVENTION The inventors of the present invention have studied the conventional problems, and found that in order to charge the toner by the metal particles, fatty acid as a surface treatment agent, It has been found that it is effective to form a thin film surface layer on the surface of the metal particles by a wet method by using a surfactant if necessary so that the metal particles themselves have a resistance value. In addition, it was possible to find a combination of carriers having good charge rise and good charge level with respect to the metal toner.

That is, the present invention is, firstly, an electrophotographic method.
Metal used in the developer for conductor pattern formation by
The metal particles are coated with a thin layer of surface treatment agent.
Secondly, the metal toner characterized in that
The metal toner according to the first aspect, wherein the surface treatment agent is a fatty acid,
Third, the weight of the surface treatment agent is larger than that of the metal particles.
The metal toner according to the first or second aspect, which is 0.1 to 1%.
Fourthly, the metal particles are produced by a wet method,
Any of the first to third, wherein the metal purity is 90% by weight or more
Fifth, the metal toner is silver particles.
The metal toner according to any one of 1 to 4 is
6, the average particle size is 0.2 to 15 μm, the first to fifth
Seventhly, the metal toner according to any one of
0.2-1m ^Two/ G, which is any one of 1-6
Eighth, the sphericity is 0.4 or more,
Ninth, the metal toner according to any one of the first to seventh
In any of the 1st to 8th, the amount of electricity is 3 to 30 μC / g
Tenthly, the metal toner described above is used as a conductor by electrophotography.
It is a carrier used as a developer for pattern formation.
The magnetic particles are covered with a resin layer.
Eleventh, the carrier to be used is the toner used in the developer.
The carrier according to claim 10, wherein the toner is a metal toner,
12, the resin is a fluororesin, a silicone resin and
At least one selected from the group consisting of acrylic resins
There is a carrier according to 10th or 11th, 13th,
The weight of the resin is 0.1 to 3% of the weight of the magnetic particles.
The carrier according to any one of items 10 to 12,
Fourteenth, the magnetic particles are ferrite or magnetite.
And at least one selected from the group consisting of iron
The carrier according to any one of items 10 to 13
No. 10 to No. 1 having an average particle size of 20 to 100 μm
16th, electrophotographic
It is a two-component developer for conductor pattern formation by the
The metal particles coated with a thin film layer of surface treatment agent.
From a toner and a carrier in which magnetic particles are coated with a resin layer.
The present invention also provides a developer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The metal toner has a metal purity of preferably 90% by weight or more, more preferably 99% by weight or more. If the metal purity is less than 90% by weight, the conductivity will decrease, which is not preferable. The average particle size of the metal toner is 0.2 to
It is preferably 15 μm, more preferably 1 to 10 μm, and its specific surface area is preferably 0.2 to ¹ m ² / g. Considering transferability and reproducibility of fine lines in the metal toner, fine particles having a large charge amount are preferable, but the particle size is less than 0.2 μm and the specific surface area is 1 m ^2.
In the case of fine particles exceeding / g, the adhesive force (van der Waals force) to the carrier surface and the like becomes strong and it becomes difficult to separate, and it becomes difficult to control the electric power (Coulomb force). on the other hand,
With a diameter exceeding 15 μm and a specific surface area of 0.2 m ²
If it is less than / g, the charge amount of the metal toner decreases, and the transferability and the reproducibility of fine lines are poor.

It is usually preferable to produce the metal particles as the core material (sometimes referred to as nuclei) of the metal toner by a wet reduction method so as to make the particle sizes uniform. For example, in the case of silver particles, a silver nitrate solution is used. A method is employed in which an amine complex solution is prepared with ammonia and the pH is adjusted if necessary, and then a reducing agent is added to precipitate silver particles. This can increase the sphericity. The sphericity of the metal toner is preferably 0.4 or more. If it does not reach 0.4, the fluidity of the developer varies, and the conductor pattern becomes non-uniform. In the present invention, the sphericity can be obtained by dividing the specific surface area value calculated from the average particle diameter by the specific surface area value measured by the BET method. Further, as the metal particles, palladium, silver,
Various metals such as gold, copper, platinum, tungsten, nickel can be used alone or in an alloy, but the conductivity,
From the standpoint of stability, cost and processability, silver particles are preferred.

Oleic acid is a surface treatment agent for forming an easily chargeable thin film layer on metal particles for metal toner.
A saturated fatty acid or an unsaturated fatty acid such as stearic acid or a phosphoric acid ester, and a surfactant and a binder are used. The above-mentioned surface treatment agent is prepared by forming metal particles in a wet method and then immediately adding the surface treatment agent to the reaction solution in an amount of 0.1 to 1% by weight based on the weight of the metal particles and stirring the mixture. It is possible to obtain surface-treated metal particles coated with a thin film layer of a surface-treating agent, which is used as a metal toner. The charge amount of the metal toner for image formation is preferably 3 to 30 μC / g, and more preferably 10 to 25 μC / g. If the addition rate of the surface treatment agent is less than 0.1% by weight, the charge amount will be less than 3 μC / g and the toner will be scattered, resulting in difficulty in handling. On the other hand, if the addition rate of the surface treatment agent is less than 1% by weight. If it exceeds, the charge amount exceeds 30 μC / g and it becomes difficult to develop.

As the carrier for charging the metal toner, those having an average particle size of 20 to 100 μm in which magnetic particles such as ferrite, magnetite and iron powder are coated with resin are preferable. The resin coating weight is preferably 0.1 to 3% with respect to the weight of the magnetic particles. When the average particle size of the carrier increases and the resin coverage decreases, the charge imparting ability decreases, while the average particle size decreases and the charge amount itself tends to increase as the resin coverage increases. Almost saturated at about 20 μm. If the average particle size exceeds 100 μm and the resin coverage falls below 0.1%, the charge imparting ability to the metal toner does not reach the predetermined range, and conversely,
If the resin coverage exceeds 3%, the charge imparting power to the metal toner exceeds the predetermined range, and the conductivity of the conductive pattern deteriorates. However, in the change in the charge amount of the metal toner due to the average particle size, the change in the charge amount due to the difference in the resin type and the surface treatment agent for the metal toner is not so large.

As the coating resin material, fluororesin, silicone resin, acrylic resin, etc. can be selected, but at the charging level between resin coating materials, fluororesin> silicone resin>
Acrylic-modified silicone resin is used in this order, and fluororesin is considered to be superior in terms of charge rising property and charge level adjustment. In addition, in the case of this resin coating, if the fluorine-modified silicone oil is added to the fluororesin coating material in an amount of 1 to 10% by weight, the charging level is remarkably increased.

An immersion method is used for the resin coating of the magnetic particles. The core magnetic particles, the resin for coating, and the solvent for making the mixed state uniform are added to a universal stirrer, and the mixture is heated with stirring, and a desired carrier is obtained through a drying step and a curing step. In this case, the solvent is selected so that the resin can be uniformly dispersed. For example, toluene,
When using a water-soluble resin such as xylene ketones, water and methanol can be selected. Further, the drying step and the curing step can be adjusted by the resin used, but the drying step is performed at 70 to 140 ° C. for 10 to 60 minutes,
In the curing process, 10 to 140-300 ℃
A range of 120 minutes is preferred.

As described above, the curing treatment is performed while manufacturing the carrier while stirring, but when a thermosetting resin such as a silicone resin is used, the resin layer on the surface of the carrier is roughened by stress due to stirring. There are cases. Therefore, the curing treatment may be stopped for a relatively short time, and the treatment for static curing may be performed in an oven or the like. In this case, the conditions of the oven are preferably 100 to 300 ° C. for 30 minutes to 5 hours, depending on the resin used.

[0020]

The present invention will be described in more detail with reference to the following examples, but it goes without saying that the technical scope of the present invention is not limited to the description of the following examples.

Example 1 1 L of a silver nitrate solution having a silver concentration of 12.4 g / liter (hereinafter, liter is represented by L) obtained by dissolving commercially available silver ingot in nitric acid was added to 37 mL of 25 wt% ammonia water. Was added to obtain an amine complex solution. Silver powder was deposited by adding 4 mL of hydrazine as a reducing agent to this solution. Unsaturated fatty acid consisting of oleic acid was added to this reaction liquid in a proportion of 0.4% by weight based on this silver powder, and the mixture was stirred to obtain a silver toner in which silver particles were coated with a surface treatment agent. The obtained silver toner has a silver purity of 99.4 as shown in Table 1.
% By weight, average particle diameter by a Microtrac particle size distribution measuring device manufactured by Nikkiso Co., Ltd. (measured using this device in the present invention) is 1.4 μm, specific surface area is 0.85 m ² / g,
The tap density was 4.0 g / cm ³ and the sphericity was 0.5, which was almost spherical.

[0022]

[Table 1]

On the other hand, it is 1.5 with respect to the weight of the ferrite particles.
Toluene is added as a solvent to a fluororesin having a weight ratio of 10% to prepare a coating liquid, and the coating liquid is added to spherical ferrite particles having an average particle diameter of 50 μm by the weight of 120 to 120 by a dipping method using a universal stirrer. 200 ° C
The mixture was heated and stirred for 1 hour to remove toluene and coat the spherical ferrite particles with a fluororesin. Next, the resin-coated particles were heat-treated at 200 ° C. for 3 hours in a heat-circulation oven to obtain a carrier.

Next, 10 parts by weight of the silver toner and 90 parts by weight of the carrier are put into a 100 ml polyethylene container and stirred under a normal environmental condition (temperature 25 ° C., humidity 65%) for 30 minutes by a ball mill to frictionally charge them. The charge amount of the silver toner was measured by a blow-off powder charge amount measuring device (TB-200 manufactured by Toshiba Chemical Co., Ltd., which is used in the present invention to measure the charge amount). As a result, Table 1
As shown in, the charge amount was 21.2 μC / g.

[Example 2] 25 in 1 L of a silver nitrate solution having a silver concentration of 12.4 g / L obtained by dissolving commercially available silver ingot in nitric acid
By adding 47 mL of wt% aqueous ammonia,
An amine complex solution was obtained. PH of this solution with an alkaline solution
After adjusting to 2 to 13, silver powder was precipitated by adding 50 mL of the reducing agent formalin (formaldehyde 37% by weight manufactured by Nippon Kasei). Unsaturated fatty acid composed of oleic acid was added to the reaction solution in an amount of 0.7% by weight based on the silver powder.
As shown in Table 1, the silver toner obtained by performing the same surface treatment as in Example 1 was added with a silver purity of 98.7% by weight, an average particle size of 1.5 μm, and a ratio of The surface area was 0.78 m ² / g, the tap density was 4.4 g / cm ³ , and the sphericity was 0.5, which was almost spherical.

Then, using the carrier obtained in Example 1, the charge amount of the silver toner was measured in the same manner as in Example 1, and as a result, as shown in Table 1, it was 21.4 μC / g. .

Example 3 Commercially available silver metal was dissolved in nitric acid to obtain a silver nitrate solution, and silver powder was deposited from this silver nitrate solution in the same manner as in Example 2. The saturated fatty acid consisting of stearic acid was dissolved in this reaction solution in an ethanol solution, added at a ratio of 0.2% by weight with respect to the silver powder, and the same surface treatment as in Example 1 was performed. As described above, the silver purity is 99.1% by weight, the average particle size is 2.5 μm, the specific surface area is 0.51 m ² / g, and the tap density is 4.0 g / c.
A silver toner having m ³ and a sphericity of 0.4 was obtained.

Then, using the carrier obtained in Example 1, the charge amount of the silver toner was measured in the same manner as in Example 1, and as a result, as shown in Table 1, it was 10.0 μC / g. .

Example 4 Silver powder was obtained in the same manner as in Example 2. Furthermore, 0.3% by weight of oleic acid was added to the silver powder, the silver purity was 99.2% by weight, and the average particle size was 2.
A silver toner having a particle size of 0 μm, a specific surface area of 0.52 m ² / g, a tap density of 5.0 g / cm ³ and a sphericity of 0.5 was obtained.

Then, using the carrier obtained in Example 1, the charge amount of the silver toner was measured in the same manner as in Example 1, and as a result, as shown in Table 1, it was 12.6 μC / g. .

Example 5 Silver powder was obtained in the same manner as in Example 2. Then, in the same manner as in Example 3, 0.1% by weight of stearic acid was added to this silver powder, and as shown in Table 1, the silver purity was 99.2% by weight and the average particle size was 4.
A silver toner having a specific surface area of 0 μm, a specific surface area of 0.24 m ² / g, a tap density of 5.0 g / cm ³ , and a sphericity of 0.6 was obtained.

Then, using the carrier obtained in Example 1, the charge amount of the silver toner was measured in the same manner as in Example 1, and as a result, as shown in Table 1, it was 3.4 μC / g. .

Comparative Example 1 Silver powder was obtained in the same manner as in Example 2. Then, the silver powder is used as it is as a silver toner without being covered with a thin film layer of a surface treatment agent. This silver toner has a silver purity of 99.4% by weight and an average particle size of 1
A little larger than 0.0 μm and a specific surface area of 0.34 m ² /
g, tap density was as low as 1.7 g / cm ^3, and sphericity was as low as 0.2.

Then, using the carrier obtained in Example 1, the charge amount of the silver toner was measured in the same manner as in Example 1, and as a result, as shown in Table 1, it was -1.1 μC / g. It was

The above Examples 1 to 5 and Comparative Example 1
As can be understood from the result, when the carrier material and the charging conditions are fixed and the metal toner species are allocated, the chargeability tends to change from −1 to 21 μC / g depending on the type of the surface treatment agent. From these results, it was possible to match the charge amount required by the system, and it was possible to arbitrarily adjust the charge amount within the range of 3 to 21 μC / g by changing the surface treatment agent and the like. In addition, it can be seen that the toner without the surface treatment of the metal particles (Comparative Example 1) cannot obtain the resistance required as the toner and cannot maintain the chargeability.

Example 6 Toluene was added as a solvent to a fluororesin having a weight ratio of 1.5% by weight with respect to the weight of ferrite particles to prepare a coating solution, and this coating solution was added to spherical ferrite particles for universal use. The mixture was heated and stirred at 120 to 200 ° C. for 1 hour by a dipping method using a stirrer to remove toluene and coat the spherical ferrite particles with a fluororesin. Next, the resin-coated particles were heat-treated in a heat-circulation oven at 200 ° C. for 3 hours to obtain a carrier having an average particle size of 50 μm.

Example 7 Toluene was added as a solvent to a silicone resin having a weight ratio of 1.5% by weight with respect to the weight of ferrite particles to prepare a coating solution, and this coating solution was added to spherical ferrite particles for universal use. The mixture was heated and stirred at 120 to 200 ° C. for 1 hour by a dipping method using a stirrer to remove toluene and coat the spherical ferrite particles with a silicone resin. Next, the resin-coated particles were heat-treated in a heat-circulation oven at 200 ° C. for 3 hours to obtain a carrier having an average particle size of 50 μm.

Example 8 Toluene was added as a solvent to an acrylic modified silicone resin having a weight ratio of 1.5% by weight based on the weight of ferrite particles to prepare a coating solution, and the coating solution was added to spherical ferrite particles. The mixture was heated and stirred at 120 to 200 ° C. for 1 hour by a dipping method using a universal stirrer to remove toluene and coat the spherical ferrite particles with an acrylic modified silicone resin. Then, the resin-coated particles were placed in a heat-circulation oven to obtain 2
Heat treatment was performed at 00 ° C. for 3 hours to obtain a carrier having an average particle size of 50 μm.

The silver toners obtained in Examples 4 and 5 were used in combination with the carriers obtained in Examples 6 to 8 in six ways, and each combination was carried out in the same manner as in Example 1. The charge amount in the case of the combination was measured, and the measured values shown in Table 2 below were obtained.

[0040]

[Table 2]

As can be understood from Table 2 above, when the type of silver toner is fixed and assigned to each carrier of different resin used, the charge amount is 0.
It tends to vary from 5 to 13 μC / g. It is considered that the carrier coated with the fluororesin (Example 6) is most easily charged, and the range of selection of the amount of charge is widened in use. On the other hand, in the carrier coated with a silicone resin (Example 7) and the carrier coated with an acrylic modified silicone resin (Example 8),
Depending on the toner to be combined, such as the toner obtained in Example 5, the charge amount will be low. Therefore, when silver toner is used, the chargeability (charge level,
A carrier coated with a fluororesin is preferable in order to obtain (charge rising property).

Example 9 Toluene was added as a solvent to a fluororesin having a weight ratio of 1.5% by weight based on the weight of ferrite particles to prepare a coating liquid, and the coating liquid was a spherical ferrite having an average particle diameter of 70 μm. In addition to the particles, 1 at 120-200 ° C by the dipping method with a universal stirrer
The mixture was heated and stirred for a period of time to remove toluene and coat the spherical ferrite particles with a fluororesin. Next, the resin-coated particles were heat-treated at 200 ° C. for 3 hours in a heat-circulation oven to obtain a carrier.

Example 10 Toluene was added as a solvent to a fluororesin having a weight ratio of 1.5% by weight with respect to the weight of ferrite particles to prepare a coating liquid, and the coating liquid was a spherical ferrite having an average particle diameter of 50 μm. In addition to the particles, heating and stirring were performed at 120 to 200 ° C. for 1 hour by a dipping method using a universal stirrer to remove toluene and coat the spherical ferrite particles with a fluororesin. Next, the resin-coated particles were heat-treated at 200 ° C. for 3 hours in a heat-circulation oven to obtain a carrier.

Example 11 Toluene was added as a solvent to a fluororesin having a weight ratio of 1.5% by weight based on the weight of ferrite particles to prepare a coating liquid, and the coating liquid was a spherical ferrite having an average particle diameter of 30 μm. In addition to the particles, heating and stirring were performed at 120 to 200 ° C. for 1 hour by a dipping method using a universal stirrer to remove toluene and coat the spherical ferrite particles with a fluororesin. Next, the resin-coated particles were heat-treated at 200 ° C. for 3 hours in a heat-circulation oven to obtain a carrier.

Using the silver toners obtained in Example 4 and Example 5 in the respective carriers obtained in Examples 9 to 11 having different average particle diameters in the respective spherical ferrite particles, six types were obtained. The combination and the charge amount in the case of each combination were measured in the same manner as in Example 1, and the measured values shown in Table 3 below were obtained.

[0046]

[Table 3]

As can be seen from Table 3 above, when the type of silver toner is fixed and the spherical ferrite particles are assigned to the above carriers (Examples 9 to 11) having different average particle diameters. The charge amount tends to change up to 2 to 13 μC / g for each average particle size of the ferrite particles used for the carrier. It is considered that the ferrite particles having a small average particle size (Example 11) used for the carrier are most easily charged among the above, and the range of selection of the charge amount is widened when used.

[0048]

The electrophotographic image forming method using the developer comprising the metal toner coated with the surface treatment agent thin film layer of the present invention and the carrier coated with the resin layer enables high charging and uniform charging. By doing so, it is possible to print and form a conductor pattern on a substrate or thin film sheet with great accuracy.
After fixing, it is possible to form a highly reliable conductor pattern having good conductivity with few pinholes.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 9/107 H01G 4/12 358 9/113 G03G 9/10 351 H01G 4/12 358 352 354 311 321 ( 72) Inventor Kimihiro Akada 7 Tsukiko Sakae-cho, Okayama-shi, Okayama Dowa Iron & Powder Co., Ltd. (72) Inventor Yoshio Hasegawa 1-2-8 Marunouchi, Chiyoda-ku, Tokyo F-Term (Reference) ) 2H005 AA12 AA13 AA15 AA29 AB02 BA02 BA06 CA02 CA11 CA12 CA30 CB03 CB04 CB06 EA01 EA05 EA07 EA10 FA02 5E001 AB03 AH01 AH06 AH09 AJ01

Claims (16)

[Claims] 1. A metal toner used as a developer for forming a conductor pattern by electrophotography, characterized in that metal particles are coated with a thin film layer of a surface treatment agent. 2. The metal toner according to claim 1, wherein the surface treatment agent is a fatty acid. 3. The metal toner according to claim 1, wherein the weight of the surface treatment agent is 0.1 to 1% of the weight of the metal particles. 4. The metal particles are produced by a wet method,
The metal toner according to claim 1, wherein the metal purity is 90% by weight or more. 5. The metal particles are silver particles.
5. The metal toner according to any one of 4 to 4. 6. The metal toner according to claim 1, which has an average particle size of 0.2 to 15 μm. 7. The specific surface area is 0.2 to ¹ m ² / g.
The metal toner according to claim 1. 8. A sphericity of 0.4 or more,
7. The metal toner according to any one of 7. 9. The metal toner according to claim 1, having a charge amount of 3 to 30 μC / g. 10. A carrier used as a developer for forming a conductor pattern by electrophotography, characterized in that magnetic particles are coated with a resin layer. 11. The carrier according to claim 10, wherein the toner used in the developer is a metal toner. 12. The carrier according to claim 10, wherein the resin is at least one selected from the group consisting of fluororesins, silicone resins and acrylic resins. 13. The carrier according to claim 10, wherein the weight of the resin is 0.1 to 3% of the weight of the magnetic particles. 14. The carrier according to claim 10, wherein the magnetic particles are at least one selected from the group consisting of ferrite, magnetite and iron. 15. The average particle size is 20 to 100 μm,
The carrier according to claim 10. 16. A two-component type developer for forming a conductor pattern by electrophotography, comprising a metal toner in which metal particles are coated with a thin film layer of a surface treatment agent and a carrier in which magnetic particles are coated with a resin layer. And a developer.