JP2907002B2 - Electrostatic latent image developing carrier, method of manufacturing the same, and image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier for developing an electrostatic latent image used to visualize an electrostatic latent image in electrophotography, electrostatic recording, and the like, a method for manufacturing the same, and an image forming method. .

[0002]

2. Description of the Related Art Conventionally, in electrophotography, an electrostatic latent image is formed on a photoreceptor or an electrostatic recording medium by using various means, and the electrostatic latent image is attached with electroconductive fine particles called toner. In general, a method of developing an electrostatic latent image by causing the electrostatic latent image to be developed is used.
In this development, carrier particles, called carriers, are mixed with the toner, and both are triboelectrically charged to impart an appropriate amount of positive or negative charge to the toner.

[0003] Carriers are roughly classified into coated carriers having a coating layer on the surface and non-coated carriers having no coating layer on the surface. The coating carrier is generally superior in consideration of the life of the developer. Therefore, various types of coated carriers have been developed and put into practical use. There are various characteristics required for the coated carrier, but it is necessary to impart appropriate chargeability (charge amount and charge distribution) to the toner, to maintain proper chargeability of the toner for a long period of time, and to change the environment such as humidity and temperature. In particular, it is particularly important not to change the chargeability of the toner, and various coated carriers have been proposed.

[0004] However, the biggest problem in using a two-component developer is that the binder resin, the charge controlling agent, the external additives, and the like, which are the components of the toner, contaminate the carrier surface.
That is, the charge controllability deteriorates with time. As a coating material for preventing surface contamination of the carrier, use of a low surface tension fluorinated alkyl (meth) acrylate resin or silicone polymer having excellent surface contamination resistance has been proposed.

The fluorinated alkyl (meth) acrylate resin has a low surface tension, but has a considerably strong negative polarity from the viewpoint of triboelectric charging due to the strong electronegativity of its constituent fluorine atom. Therefore, when a large amount of a fluorinated alkyl (meth) acrylate resin is used as the negative charge imparting carrier, the ability to impart a negative charge to the toner is reduced.

[0006] Silicone polymers have a low surface tension and are as effective as fluorinated alkyl (meth) acrylate resins for surface contamination of carriers, but silicone polymers are also triboelectrically charged. In view of this, it is located at a middle position, and cannot be said to be sufficient as a negatively charged carrier. These polymers have a problem that the adhesion of the carrier to the core substance is poor, the mechanical strength of the coating itself is weak, and that the frictional charging of the toner is largely dependent on the environment (temperature and humidity). .

Therefore, in order to improve the adhesion between the fluoropolymer and the core material of the carrier, an intermediate layer of an epoxy polymer is used (see JP-A-49-51590). Block copolymers and graft copolymers (see JP-A-57-99653 and JP-A-60-202451) and fluorine-containing polymers containing a hydrolyzable silyl group (Japanese Patent Laid-Open No.
It has been proposed to use JP-A-16573 and JP-A-2-24670. However, although the above-mentioned carrier is effective in improving the adhesion, it has a low ability to impart negative charge to the toner, so that there is room for improvement.

In order to improve the adhesion of the silicone polymer coating layer, it has been proposed to use a coupling agent (see JP-A-60-191560 and JP-A-62-121463). ) Has the effect of improving the adhesion to the carrier core substance, but does not have sufficient charge-imparting ability as a negative-charge-imparting carrier.

On the other hand, in order to improve the stability of imparting a negative charge to the toner and the charge retention, a coated carrier in which a triboelectric charge control layer and a releasable surface layer are laminated on a carrier core material has been proposed (Japanese Patent Application Laid-Open No. H11-157556). (See Japanese Unexamined Patent Publication No. Sho 61-110159 and Japanese Unexamined Patent Publication No. Sho 61-110160), there remains room for improvement in the environmental dependency of charge and the charge retention. In particular, in order to achieve high image quality, it is necessary to use a toner having a small particle diameter, so that the charge applying ability and the charge imparting ability maintaining property are significantly higher than those of the carriers used in conventional developers. Because of the necessity, the use of the above-mentioned carrier was insufficient for the ability to impart negative charge.

It has been proposed to use a thermosetting acrylic resin, which makes the carrier more positively chargeable, in order to enhance the ability to impart a negative charge to a toner using a polyester resin as a binder resin. Kaihei 4 309965
However, when these resins are used, the ability to impart a charge to the toner is certainly improved, but there is room for improvement in the charge retention and the environmental characteristics of the charge.

[0011]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a carrier for developing an electrostatic latent image having the following features, a method of manufacturing the same, and an image forming method. is there. (1) To improve the negative charge imparting property to the toner and to improve the charge maintaining property. (2) Improve the strength of the coating, prevent peeling of the coating resin, and extend the life of the carrier. (3) The surface of the carrier can be prevented from being contaminated by the material constituting the toner.

[0012]

Means for Solving the Problems The present inventors have disclosed the above-mentioned JP-A-61-110159 and JP-A-61-110110.
No. 160, the coated carrier obtained by laminating a triboelectric charge control layer and a releasable surface layer on a carrier core material, as a result of further intensive studies to improve the above-mentioned disadvantages,
It has been found that a carrier in which a resin coating layer is formed via the specific metal oxide intermediate layer can achieve the above object,
The present invention has been completed. The configuration of the present invention is as follows.

(1) Static electricity obtained by providing a coating layer on a core material
In the carrier for developing a latent image, aluminum is provided on the core material.
Selected from the group ofium, magnesium, zinc and lead
Metals formed using one or more metal alkoxides
Intermediate layer consisting of oxide and fluorinated alkyl
(Meth) acrylate resin and dimethylpolysiloxane
The surface layer of at least one resin selected from the group of
A carrier for developing an electrostatic latent image, comprising:

[0014] (2) the core material is ferrite particles, magnetite particles, and, according to claim 1, characterized in that selected from the group of particles dispersed magnetic powder in the resin A carrier for developing an electrostatic latent image.

[0015] (3) A method of providing a coating layer on the core material to produce an electrostatic latent image developing carrier, aluminum
One selected from the group consisting of magnesium, zinc, and lead
Using alkoxide or metal, after forming the intermediate layer of metal oxide on the core material, a fluorinated alkyl (main
(T) Acrylate resin and dimethylpolysiloxane
The method for producing a carrier for developing an electrostatic latent image according to the above (1 ) or (2 ), wherein the surface layer is formed by coating at least one resin selected from the group of resins .

(4) An electrostatic latent image is formed by using a developer obtained by mixing the carrier for developing an electrostatic latent image according to the above (1) or (2) , and a toner having a binder resin and a colorant. An image forming method characterized by visualizing a latent image on a holding member.

[0017]

[0018]

[0019]

[0020]

Hereinafter, the present invention will be described specifically. The carrier for developing an electrostatic latent image having two or more coating layers on the surface of the core material according to the present invention is provided as a first layer of metal oxide film close to the core material having magnetism to impart negative charge to toner. It has a function of improving the ability, that is, it has a strong positive polarity in terms of triboelectric charging compared to the core material, and has a high affinity with the core material, and has a high affinity with the resin to be coated as the second layer. Use a material with high adhesion.

Ferrites and magnetites generally used are relatively negative in metal oxide, which is a main component of the ferrite or magnetite, with respect to a styrene resin, an acrylic resin, or a polyester resin as a binder resin constituting a toner. Poor charging ability. In the case of resin-dispersed magnetic particles in which magnetic fine particles are dispersed in a resin, it is possible to relatively freely select the triboelectric series depending on the type of the resin used as the binder, but the negative charge applied to the toner is reduced. In some cases, the charging ability is insufficient.

Accordingly, the present invention provides an aluminum,
By forming an oxide coating of at least one metal from magnesium, zinc and lead, the triboelectric series can be controlled independently of the material used for the core material.
The coating amount of the metal oxide film is 0.01 to 5.0% by weight, preferably 0.0% by weight, based on the weight of the core material.
A range of 1 to 2.0% by weight is suitable. 0.01% by weight
If the amount is less than 50% by weight, the effect does not appear. In particular, aluminum and magnesium are preferably used as the metal.

As the magnetic core material used in the present invention, ferrite or magnetite can be suitably used from the viewpoint of magnetic properties such as saturation magnetization and residual magnetization and the surface properties of particles.
The average particle size of these magnetic particles is preferably in the range of 10 to 100 μm. In particular, in order to impart sufficient charge to the fine particle toner having an average particle diameter of 9 μm or less in order to achieve high image quality, a toner having an average particle diameter of 70 μm or less is suitably used. If the average particle size of the magnetic particles is smaller than 10 μm, the powder fluidity of the carrier particles is extremely deteriorated, and the transportability of the developer to the developing roll and the agitation in the developing machine are undesirably reduced. On the other hand, if it is larger than 100 μm, the magnetic brush of the developing roll becomes coarse, and the image quality of a copied image is deteriorated.

In the present invention, the first material formed on the core material
Materials for forming the metal oxide film of the layer include the following general
Can be produced from a metal alkoxide represented by the formula
You. M (OR)_m M: Al, Mg, Pb or Zn R: C_nH_{2n + 1}(N is an integer of 1 to 5, preferably 1 to 4
M: 2 or 3 Specifically, Al (OCH_Three)_Three, Al (OC_TwoH_Five)
_Three, Al (O-i-C_ThreeH₇)_Three, Al (O-i-C
_FourH₉)_Three, Mg (OC_TwoH_Five)_Two, Mg (O-i-C _Three
H₇)_Two, Pb (O-i-C_ThreeH₇)_Two, Zn (OC_TwoH
_Five)_TwoEtc. can be suitably used. These metals
By using alkoxide, nanometer
Easy to apply metal oxide coating with stable thickness on core material
Can be formed.

These metal alkoxides are hydrolyzed to prepare a sol solution of a metal hydroxide, and further deflocculated to adjust the viscosity, thereby preparing a coating solution. This solution is applied to a substrate and dehydrated and polycondensed during heating and drying to form a coating film.

In the present invention, the low surface tension polymer having a releasing property for forming the second layer resin film on the first layer metal oxide film includes perfluoroalkyl alcohol having 6 to 10 carbon atoms. A polymer mainly composed of a perfluoroalkyl (meth) acrylate monomer derived from (meth) acrylic acid can be suitably used. This perfluoroalkyl (meth) acrylate monomer is used for the purpose of improving the heat preservability of the carrier, the charge controllability, and the adhesion to the first layer as long as the low surface energy is not extremely reduced. May be copolymerized.

The monomers used for the copolymerization include styrene, α-methylstyrene, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
Alkyl (meth) acrylates such as isopropyl (meth) acrylate and butyl (meth) acrylate; dimethylaminoethyl (meth) acrylate, N-vinylpyrrolidone, acroylmorpholine, vinylpyridine and the like. Can be. Further, the resin composed of these monomers may be a polymer blend with another resin.

In the case of a polymer containing a perfluoroalkyl (meth) acrylate monomer as a main component, the polymer may be a perfluoroalkyl (meth) acrylate monomer depending on the molecular chain length of the perfluoroalkyl group. Preferably, it is contained in a range of 5 mol% or more and less than 50 mol%. Also, when forming and using a polymer blend with another polymer, it is preferable to contain 5 mol% or more as a monomer component with respect to the entire polymer. When the amount of the perfluoroalkyl (meth) acrylate monomer is less than 5 mol%, the coating polymer does not exhibit low surface tension and the surface contamination resistance is reduced. On the other hand, when the content is 50 mol% or more, the negative polarity of the coating resin itself becomes large, so that the ability to impart negative charge to the toner becomes small.

When the perfluoroalkyl (meth) acrylate monomer is copolymerized with another monomer, it may be a random copolymer or a graft or block copolymer. Further, in order to improve the strength of these coating polymers themselves and to further improve the adhesion with the metal oxide layer formed on the core substance, they may be copolymerized with a monomer having a hydroxyl group or a carboxyl group. Absent. Further, by using a cross-linking agent reactive with these functional groups, the strength of the coating polymer itself can be further improved.
As the crosslinking agent, a polyfunctional isocyanate compound or a melamine compound can be suitably used.

The amount of the resin for coating the first layer in the present invention is in the range of 0.1 to 5% by weight, preferably 0.3 to 3% by weight based on the weight of the core material. .
When the amount is less than 0.1% by weight, the effect of the coating polymer hardly appears, and when the amount is more than 5% by weight, the resistance of the carrier changes, which is not preferable. In addition, the first layer and the second layer
It is preferable that the total coating amount of the layers is 5% by weight or less. Exceeding this is not preferable because the resistance of the carrier changes.

In the present invention, as a method for forming the first and second layers on the magnetic core material, a solution obtained by hydrolyzing a metal alkoxide is used for the first layer, and a polymer organic solvent is used for the second layer. A method of spray drying with a spray dryer using a solution or a method of immersion drying with a heated vacuum degassing type coater can be applied. Especially,
The use of a heated vacuum degassing type coater is preferable because the coating state can be precisely controlled. When a crosslinked structure is formed in the coating layer, the coating liquid can be further dried and then heated to accelerate the crosslinking reaction.

The toner used in combination with the carrier of the present invention is a colored particle comprising at least a binder resin and a colorant. Examples of the binder resin include a styrene resin, a (meth) acrylate resin, and a styrene resin. ─Butadiene-based resin, polyester-based resin, urethane-based resin, amide-based resin and the like can be used.

Examples of the colorant used in the toner include a black colorant such as carbon black, CI Pigment Blue 15:
1, CI Pigment Blue 15: 2, CI Pigment Blue 1
Organic pigments such as 5: 3, CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 17, CI Pigment Red 57: 1, and Pigment Red 122 can be suitably used.

[0035]

According to the present invention, the composition of the magnetic particles used in the core material has two or more coating layers on the surface of the magnetic core particles and the first metal oxide layer has a triboelectric charge control function. Irrespective of this, a sufficient negative charging property can be imparted to the toner. Further, since this metal oxide thin layer is formed from a metal alkoxide, it can be easily and stably coated on the surface of the magnetic core material particles.

Further, since the resin to be coated on the first layer is a polymer having a low surface tension, contamination of the carrier surface due to toner components such as a binder resin, a coloring material, a charge control agent and an external additive is prevented. Since it can be effectively prevented, stable charging characteristics can be maintained for a long period of time.

[0037]

The present invention will now be described by way of examples, which should not be construed as limiting the invention. (Preparation of coating solution from metal alkoxide) Aluminum isopropoxide 1 mol Ion-exchanged water adjusted to PH = 3 100 mol This was kept at room temperature and reacted for 6 hours to produce boehmite which is a monohydrate of alumina. I let it. 1 N hydrochloric acid was added to this solution so that HCl was 0.1 to 0.5 mol per mol of boehmite, the mixture was aged, peptized, and an alumina sol was prepared.

(Production Example 1 of Alumina Coated Ferrite) 100 parts by weight of ferrite particles (manufactured by Powder Tech Co., Ltd., average particle size 50 μm) 18 parts by weight of the above alumina sol solution 50 parts by weight of isopropyl alcohol The above-mentioned materials are put into a heated vacuum degassing type kneader. After stirring for 30 minutes, the mixture was heated to 70 ° C. and gradually reduced in pressure to remove the solvent, and further heated at 150 ° C. for 30 minutes to prepare alumina-coated ferrite particles a.

(Production Example 2 of Alumina Coated Ferrite) 100 parts by weight of ferrite particles (manufactured by Powder Tech, average particle size 50 μm) 30 parts by weight of the above alumina sol solution 30 parts by weight of isopropyl alcohol The above materials were prepared under the same conditions as in Production Example-1. This treatment produced alumina-coated ferrite particles b.

(Preparation Example 3 of Alumina-Coated Magnetite-Dispersed Resin Particles) Magnetite-dispersed phenolic resin particles (magnetite content: 45% by weight, average particle diameter: 50 μm) 100 parts by weight Alumina sol solution: 20 parts by weight Isopropyl alcohol: 40 parts by weight The material was treated under the same conditions as in Production Example 1 to produce alumina-coated resin-dispersed particles c.

Example 1 (Preparation of Coated Ferrite Carrier A) Alumina-coated ferrite particles a 100 parts by weight perfluorooctyl methacrylate-methyl methacrylate copolymer (copolymer molar ratio 20/80, critical surface tension 2. 0 × 10 ⁻⁴ N / cm) 1 part by weight Methyl ethyl ketone 20 parts by weight The above-mentioned material was put into a heating vacuum degassing type kneader, stirred for 30 minutes, heated to 90 ° C., and gradually reduced in pressure to remove the solvent. Thus, a coated ferrite carrier A was prepared.

(Production Example of Toner A) 95 parts by weight of linear polyester (bisphenol A) 5 parts by weight of carbon black having a primary average particle diameter of 45 m μm The above-mentioned materials were put into a pressure kneader, melt-kneaded, cooled, and jetted. It was milled and classified to prepare black colored particles having a volume average diameter of 7 μm. To 100 parts by weight of the black colored particles, 0.1% of a surface-treated titanium oxide having a primary particle diameter of 15 nm was added.
8 parts by weight using a Henschel mixer, and toner A having surface-treated titanium oxide adhered to the surface of black colored particles
It was created.

(Evaluation) 100 parts by weight of the coated ferrite carrier A and 8 parts by weight of the toner A were mixed to prepare a black developer, and a high temperature and high humidity environment (28 ° C., 85%) and a low temperature and low humidity environment (10 ° C., 15%), and
The results are shown in Table 1. Then, the above-mentioned developer is used as a digital full-color copier Acolor 635 manufactured by Fuji Xerox Co., Ltd.
When a continuous copy test of 50,000 sheets was performed in the monochromatic mode with the modified machine, a clear image without image fog was obtained until the end.

Example 2 (Preparation of Coated Ferrite Carrier B) Alumina-coated ferrite particles b 100 parts by weight Perfluorooctyl methacrylate-methyl methacrylate copolymer (copolymer molar ratio 20/80, critical surface tension 2. 0 × 10 ⁻⁴ N / cm) 1 part by weight Methyl ethyl ketone 20 parts by weight The above-mentioned material was put into a heating vacuum degassing type kneader, stirred for 30 minutes, heated to 90 ° C., and gradually reduced in pressure to remove the solvent. Thus, a coated ferrite carrier B was prepared.

(Evaluation) 100 parts by weight of the coated ferrite carrier B and 8 parts by weight of the toner A of Example 1 were mixed to prepare a black developer, and a high temperature and high humidity environment (28 ° C., 85
%), And charging characteristics in a low-temperature and low-humidity environment (10 ° C., 15%) were evaluated. The results are shown in Table 1. Then, the above-mentioned developer was used for a digital full-color copier Aco manufactured by Fuji Xerox Co., Ltd.
When a continuous copy test of 50,000 sheets was performed in the single color mode using a modified lor635 machine, a clear image without image fog was obtained until the end.

Example 3 (Preparation of Coated Ferrite Carrier C) Alumina-coated ferrite particles b 100 parts by weight Dimethylpolysiloxane resin-based varnish (SR2411 manufactured by Toray Dow Corning Co., Ltd., critical surface tension 2.1 × 10 ⁻⁴ N / cm) 2.5 parts by weight Toluene 10 parts by weight The above materials were put into a heated vacuum degassing type kneader, stirred for 30 minutes, heated to 90 ° C., and gradually reduced in pressure to remove the solvent, thereby coating the ferrite carrier C. It was created.

(Evaluation) 100 parts by weight of the coated ferrite carrier C and 8 parts by weight of the toner A of Example 1 were mixed to prepare a black developer.
%), And charging characteristics in a low-temperature and low-humidity environment (10 ° C., 15%) were evaluated. The results are shown in Table 1. Then, the above-mentioned developer was used for a digital full-color copier Aco manufactured by Fuji Xerox Co., Ltd.
When a continuous copy test of 50,000 sheets was performed in the single color mode using a modified lor635 machine, a clear image without image fog was obtained until the end.

Example 4 (Preparation of Coated Ferrite Carrier D) Alumina-coated resin dispersed carrier particles c 100 parts by weight perfluorooctyl methacrylate-methyl methacrylate copolymer (copolymer molar ratio 50/50, critical surface Tension 2.1 × 10 ⁻⁴ N / cm) 1.5 parts by weight Methyl ethyl ketone 20 parts by weight The above-mentioned material was charged into a heating vacuum deaeration type kneader, stirred for 30 minutes, heated to 90 ° C., and gradually reduced in pressure. The solvent was removed to prepare a coated ferrite carrier D.

(Evaluation) 100 parts by weight of the coated ferrite carrier D and 10 parts by weight of the toner A of Example 1 were mixed to prepare a black developer, and the black developer was prepared.
%), And charging characteristics in a low-temperature and low-humidity environment (10 ° C., 15%) were evaluated. The results are shown in Table 1. Then, the above-mentioned developer was used for a digital full-color copier Aco manufactured by Fuji Xerox Co., Ltd.
When a continuous copy test of 50,000 sheets was performed in the single color mode using a modified lor635 machine, a clear image without image fog was obtained until the end.

Comparative Example 1 (Preparation of Coated Ferrite Carrier E) Ferrite particles (manufactured by Powdertech, average particle diameter 50 μm) 100 parts by weight Perfluorooctyl methacrylate / methyl methacrylate copolymer (copolymer molar ratio: 20 / 80, critical surface tension 2.0 × 10 ⁻⁴ N / cm) 1.5 parts by weight Methyl ethyl ketone 20 parts by weight The above-mentioned materials were charged into a heated vacuum degassing type kneader, stirred for 30 minutes, and then heated to 90 ° C. The solvent was removed by gradually reducing the pressure to prepare a coated ferrite carrier E.

(Evaluation) 100 parts by weight of the coated ferrite carrier E and 8 parts by weight of the toner A of Example 1 were mixed to prepare a black developer.
%), And the charging characteristics in a low-temperature and low-humidity environment (10 ° C., 15%) were evaluated. As shown in Table 1, the charging amount was low. When the above developer was subjected to a continuous copy test in a single-color mode using a modified digital full-color copier Acolor 635 manufactured by Fuji Xerox Co., Ltd., the charge amount of the carrier was significantly reduced, and fog occurred when 10,000 copies were copied. Test aborted.

Comparative Example 2 (Preparation of Coated Ferrite Carrier F) Ferrite particles (manufactured by Powdertech, average particle size: 50 μm) 100 parts by weight Dimethylpolysiloxane resin-based varnish (SR2411 manufactured by Toray Dow Corning Co., Ltd., critical surface tension: 2.) 1 × 10 ⁻⁴ N / cm) 2.5 parts by weight Toluene 10 parts by weight The above-mentioned material was charged into a heated vacuum degassing type kneader, stirred for 30 minutes, heated to 90 ° C., and gradually reduced in pressure to remove the solvent. By removing, a coated ferrite carrier F was prepared.

(Evaluation) 100 parts by weight of the coated ferrite carrier F and 8 parts by weight of the toner A of Example 1 were mixed to prepare a black developer.
%), And the charging characteristics in a low-temperature and low-humidity environment (10 ° C., 15%) were evaluated. As shown in Table 1, the charging amount was considerably low. When the above developer was subjected to a continuous copy test in a single color mode using a modified Fuji Xerox digital full-color copier Acolor 635, the charge amount of the carrier was significantly reduced, and fog occurred when 5,000 sheets were copied. Test aborted.

Comparative Example 3 (Preparation of Coated Ferrite Carrier G) Magnetite-dispersed phenol resin particles (magnetite content: 45% by weight, average particle size: 50 μm) 100 parts by weight Perfluorooctyl methacrylate / methyl methacrylate copolymer (Copolymerization molar ratio 20/80, critical surface tension 2.0 × 10 ⁻⁴ N / cm) 1.5 parts by weight Methyl ethyl ketone 20 parts by weight The above-mentioned material was charged into a heated vacuum degassing kneader, and stirred for 30 minutes. , 90 ° C., and gradually reduced the pressure to remove the solvent, thereby preparing a coated ferrite carrier G.

(Evaluation) 100 parts by weight of the coated ferrite carrier G and 8 parts by weight of the toner A of Example 1 were mixed to prepare a black developer.
%), And the charging characteristics in a low-temperature and low-humidity environment (10 ° C., 15%) were evaluated. As shown in Table 1, the charging amount was low. Then, when the above developer was subjected to a continuous copy test in a single color mode using a modified digital color full-color copying machine Acolor 635 manufactured by Fuji Xerox Co., Ltd., the charge amount of the carrier was significantly reduced, and fog occurred when copying 10,000 sheets. Test aborted.

[0056]

[Table 1]

[0057]

According to the present invention, by adopting the above-mentioned constitution, a good negative charge can be given to the toner, the charge retention can be greatly improved, and
It has become possible to provide a carrier for developing an electrostatic latent image having a high coating strength and a long life.

────────────────────────────────────────────────── (5) Continuation of the front page (51) Int.Cl. ⁶ Identification code FI G03G 9/10 331 351 361 15/08 507L (56) References JP-A-7-181743 (JP, A) JP-A-7-181 181744 (JP, A) JP-A-7-181745 (JP, A) JP-A-54-24637 (JP, A) JP-A-59-127057 (JP, A) JP-A-58-168056 (JP, A) JP-A-3-231755 (JP, A) JP-A-61-110159 (JP, A) JP-A-62-295076 (JP, A) JP-A-3-73965 (JP, A) JP-A 64-35563 (JP, A) JP-A-1-133067 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 9/10

Claims (4)

(57) [Claims] An electrostatic latent image comprising a core material and a coating layer provided on the core material.
In the carrier for development, aluminum is added on the core material.
One selected from the group consisting of magnesium, zinc, and lead
Metal oxidation formed using alkoxides of the above metals
Intermediate layer consisting of a substance and a fluorinated alkyl
(T) Acrylate resin and dimethylpolysiloxane
Has a surface layer of at least one resin selected from the group of resins
A carrier for developing an electrostatic latent image. Wherein said core material is ferrite particles, magnetite particles, and static according to claim 1, characterized in that selected from the group of particles dispersed magnetic powder in the resin Electrostatic latent image carrier. 3. A method of providing a coating layer on the core material to produce a carrier for developing an electrostatic latent image, aluminum, Ma
Magnesium, zinc and using one or more <br/> metal alkoxide selected from the group of lead, metal oxide on the core material
After forming the intermediate layer of fluorinated alkyl (meth)
Group of related resin and dimethylpolysiloxane resin
Claim 1 or 2 electrostatic latent image method for producing a developing carrier according to one or more resins that are selected and forming a surface layer by coating from. 4. An electrostatic latent image carrier according to claim 1 or 2, wherein the developer is a mixture of a binder resin and a toner having a colorant. An image forming method characterized by visualizing a latent image.