JP2003098746A - One-component toner for electrostatic charge development, toner container and image forming apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide toner for image forming which can obtain an excellent image without causing surface staining or toner scattering even in long-term use, and to provide a container in which the toner is stored and an image forming apparatus. SOLUTION: The one-component toner for electrostatic charge development consists of particles at least incorporating binding resin and a colorant, and the colorant is metallic material blackened by surface treatment with pigment and/or dyestuff or metallic material black itself, and its saturation magnetization value is <=0.01 to 3 emu/g and its true specific gravity is within 1.33 to 1.62 g/cm<3> .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming toner used for developing an electrostatic latent image such as an electrophotographic method, an electrostatic recording method, an electrostatic printing method, a container containing the toner and an image forming method. Regarding the device.

[0002]

2. Description of the Related Art In recent years, as an example of developing a latent image by an electrophotographic method, an electrostatic recording method, etc., a developing magnet roller having a sleeve internally provided with a magnetic field generating means and a magnetic one-component toner are used. The methods used in combination are popular. Generally, an electrostatic latent image developing operation using a magnetic one-component toner is performed by rotating a sleeve, rotating an internal magnet, or both of them. Rotation is performed for development. However, at this time, the rotational speed of the sleeve or magnet is selected by setting the moving speed of the magnetic toner to 2 to 4 times that of the latent image so that the pitch of the magnetic poles does not appear in the image, so that the uniformity of the image density is ensured. In order to sufficiently secure it, the rotation of the magnet must be made considerably fast, and a powerful motor is required to drive it, which naturally leads to an increase in size of the device.

In order to avoid such inconvenience, a one-component developer having no magnetism is disclosed in Japanese Examined Patent Publication No. 41-9475. Then, here, it is considered to apply a toner member having a thin toner layer on the surface thereof in the vicinity of the latent image forming body so as to fly the toner only to the latent image in a non-contact relationship. In this document, the retention of toner is achieved by suctioning and adsorbing the toner onto a web having an appropriate adhesive property or a film sheet which has been previously charged. However, in this method, the length of the sheet and the web is limited, and it is not suitable for continuous copying and printing.

As a means for solving such a problem, a method is disclosed in Japanese Patent Laid-Open No. 229065/1985, in which a developer carrying member is made endless and development is performed by flying a non-magnetic one-component toner, and the development is transferred to a recording paper. It is disclosed. In this example, a uniformizing member is brought into contact with a developing roller to form a thin layer of toner, and a developing bias such as DC superimposing AC is applied to develop the latent image. JP-A-50-3053
Japanese Laid-Open Patent Publication No. 7-76 discloses a method for increasing the image density by the pulse bias method. Furthermore, JP-A-47
Japanese Patent Laid-Open No. 12635 and Japanese Patent Application Laid-Open No. 50-10143 disclose a structure of a developer carrier having a minute pattern of an insulator portion (dielectric portion) and a conductor portion on the surface. These use a minute electric field to form toner peaks and troughs according to the minute pattern, and adhere toner corresponding to the potential level of the latent image, aiming for multi-layering. Regardless of which method is used, the toner characteristics on the developing roller are important because the amount of developer applied to the latent image carrier changes depending on how the toner is applied to the developing roller. .

In addition, various non-magnetic one-component developing methods which do not use a carrier have been proposed in Japanese Patent Application Laid-Open No. 58-116559, but for a toner which requires a low melting point and a sharp melt, the fluidity is improved. When the intended external additive is attached to the surface of the toner, the external additive receives a mechanical hazard such as when the toner passes through the developing roller and the developer coating blade due to the use of the developing unit, and the toner is removed. By being embedded in the surface, the toner characteristics on the developing roller are likely to change. In particular, a fluidity improver externally added for the purpose of improving the fluidity of the toner stabilizes the toner charge amount on the developing roller over time due to the change in toner characteristics due to being embedded in the toner surface. To do so, to stably secure a sufficient amount of development on the latent image carrier, to prevent background fog on the image, etc. are still mentioned as problems to be solved.

The toner used in such a non-magnetic one-component developing system is one in which a colorant or the like is dispersed in a binder resin, and is used as a general non-magnetic colorant for black. , Carbon black has been used effectively. However, carbon black has an effect of imparting conductivity due to its structural one, and when a large amount of carbon black is used particularly for the purpose of increasing the degree of coloring, the electric resistance of the toner itself becomes low, and the charge retention ability decreases, The chargeability will decrease and the amount of reversely charged toner and weakly charged toner will increase,
Problems such as a so-called background stain phenomenon in which toner particles are developed and toner scattering occur in places other than the image portion where the electrostatic latent image is formed, and the carbon black content is limited. In particular, these phenomena are remarkable because when the charge imparting effect of the charge imparting member decreases with time, toner that is not sufficiently charged or weakly charged toner that is slightly charged with the opposite polarity is likely to occur. It was Generally, the one-component toner containing almost no carbon black is mainly a magnetic one-component toner containing a magnetic substance instead of carbon, and the toner contains 20 to 50 wt% of the magnetic substance.
And the toner itself has a high saturation magnetization of about 10 to 40 emu / g, and the magnetic substance actually contained is 20 wt%.
-40 wt% is very large, and the value of true specific gravity is 1.6-1.9.
It was as high as g / cm ³ . It is a non-magnetic or weakly magnetic non-magnetic toner, and has an appropriate specific gravity.
Up to now, there has been no particular product containing as little carbon black as possible.

Further, in recent years, the demand for high-quality images has increased in the market, and it has become impossible to obtain sufficient high image quality with conventional toner having a volume average particle size of 10 to 15 μm.
Further, a toner having a small particle size is required. However, as the particle size of the toner becomes finer, various problems are more likely to occur, and in particular, the adhesion of the toner itself is increased, so that the toner is liable to be contaminated with the charge imparting member. The charge imparting ability of the charge imparting member and the like is likely to decrease, and the margin for background stains and toner scattering tends to become more severe.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming toner capable of obtaining a good image without causing background stains and toner scattering even after long-term use, a container containing the toner, and An object is to provide an image forming apparatus.

[0009]

Means for Solving the Problems The above-mentioned problems can be solved by (1) "particles containing at least a binder resin and a colorant, and the colorant being blackened by a surface treatment with a pigment and / or a dye. Or a metallic material which itself is black and has a saturation magnetization value of 0.01 to 3 emu /
g or less and true specific gravity in the range of 1.33 to 1.62 g / cm ³ "one-component toner for electrostatic charge development", (2) "the toner is 0.1 part by weight of the colorant. 01-5
a one-component toner for electrostatic charge development according to item (1), characterized in that it contains carbon black in an amount of wt%.
(3) “Saturation magnetization of the toner is 0.01 to 2 emu / g
Or the above (1) or (2)
Monocomponent toner "for electrostatic charge development according to section (4)" the first (1) a true specific gravity of the toner is characterized in that it is a 1.40~1.55g / cm ³ section to the (3 (5) The black metallic material used as the colorant is selected from at least Mn, Ti, Cu, Si and C for hematite or maghemite. The electrostatic charge development according to any one of the above items (1) to (4), characterized by containing a compound of each element, an oxide thereof, or a mixture thereof. One-component toner ", (6)" A black metal material used as a colorant has an average minor particle diameter of 0.01 to
0.8 μm, the one-component toner for electrostatic charge development according to any one of items (1) to (5), and (7) “inorganic fine powder as an external additive. The one-component toner for electrostatic charge development according to any one of items (1) to (6) above, wherein the inorganic fine powder is at least one of silica and / or titanium oxide. (8) "One component toner for electrostatic charge development according to any one of items (1) to (7), wherein the binder resin is at least one polyester resin", (9) "One-component toner for electrostatic charge development according to any one of items (1) to (8), characterized in that the toner contains a release agent", (10) The release agent contains a small amount of free fatty acid type carnauba wax, montan wax and oxidized rice wax. Both the first (9) one-component toner for electrostatic charge development according to claim, characterized in that one "(11)" volume average particle diameter of the toner is 2.5 to 1
It is achieved by the one-component toner for electrostatic charge development according to any one of the above items (1) to (10).

The above object can be achieved by (12) of the present invention "a toner container filled with the toner for electrostatic charge development according to any one of the above items (1) to (11)". It

Further, the above object can be achieved by (13) of the present invention, "the image forming apparatus equipped with the toner container according to the above (12)".

The present inventors have conducted extensive studies to solve the problems of the present invention, and as a toner for one component, particles containing at least a binder resin and a coloring agent, and the coloring agent is a pigment and / or a dye. The metallic material blackened by surface treatment by itself or the metallic material itself is black, and the saturation magnetization value of the toner is 0.01 to ³ mu / g and the true specific gravity is 1.33 to 1.62 g / cm ³ . It was found that the above-mentioned drawbacks can be solved by the above.

Particularly, in the present invention, in the toner containing no carbon black, the improvement of the various problems presented above is considered by defining the subtle saturation magnetization value and the true specific gravity without lowering the blackness. However, the present inventors have found that a toner having a saturation magnetization value and a true specific gravity in a specific range using a metal material blackened by surface treatment / or various measures is an effective solution to the above problem. I found that.

Further, even when carbon black is contained in a part of the colorant of the toner, the content of carbon black is 0.01 to 5 wt%, preferably, carbon black should be reduced as much as possible. When the content is at least 5 wt% or less, and more preferably 3 wt% or less, the occurrence of defects with respect to the above problems is reduced to an acceptable level, and in terms of color tone, the blackness is further increased with a small amount of inclusion, which is advantageous. However, it is preferable not to contain it at all. Here, if it is more than 5 wt%, the above-mentioned problem is likely to occur remarkably. Furthermore,
The toner of the present invention may be used as a toner exclusively for black, or may be used as a black toner used in full color, and can be applied in any case. In particular, when it is used as a full color black toner, other colors are used. Unlike black toner, which has a different charging behavior due to lower toner resistance when carbon black is used compared to dyes and pigments used in colors, the resistance maintains a high level like other color toners. Therefore, only the black toner is advantageous because it is not necessary to individually design the charging member.

The toner saturation magnetization is 5 em.
u / g or less, particularly preferably 0.01 to 2 emu / g
By using the toner which is, even if a small amount of weakly charged toner or reversely charged toner that easily migrates to the non-image area is generated, it is possible to prevent the migration to the non-image area due to the delicate magnetic binding force, and the occurrence of background stain The size of the developing machine can be reduced because it is possible to suppress toner scattering and the magnetic characteristic level that does not require the use of a powerful drive motor, which was an obstacle to miniaturization when using magnetic toner. Is possible, and 0.
If it is less than 01 emu / g, the magnetic transporting force becomes weak enough to be almost ineffective, which easily causes toner scattering and development unevenness, and the polishing effect on the surface of the photoreceptor becomes insufficient, resulting in filming. Is more likely to occur.

On the other hand, when the saturation magnetization exceeds 5 emu / g, the magnetic binding force on the developing sleeve increases, the developability tends to decrease, and the drive motor itself needs to be relatively strong. It could be one of the obstacles to the miniaturization of the device. Here, for the measurement of magnetic properties, a magnetization measuring device BHU-60 manufactured by Riken Denshi Co., Ltd. was used. From a history curve obtained when a magnetic field was swept up to 10 kOe in a toner filled in a cell having an inner diameter of 7 mmφ and a height of 10 mm. , Saturation magnetization and residual magnetization were determined.

Further, the true specific gravity of the toner is 1.33 to 1.6.
2 g / cm ³ , particularly preferably 1.40 to 1.56 g
/ Cm ³ is also important as compared with a normal non-magnetic toner, which makes it easy for the toner to flow, so that good chargeability can be obtained and a high-quality image can be obtained. .

The true specific gravity of the toner is 1.33 g / cm.
When it is less than ³ , the toner becomes difficult to flow and the chargeability is deteriorated, and when a large amount of an external additive is added for the purpose of compensating for this decrease, various problems such as occurrence of various problems occur.

On the other hand, the true specific gravity of the toner is 1.62 g / cm.
If it exceeds ³ , the developability will decrease and the required toner weight for the same amount of adhesion will also increase, which is also a disadvantage in terms of cost. There was a problem such as commutation. Therefore, it is considered that there is a certain appropriate range for the toner fluidity of the device and the true specific gravity for the downsizing of the device. Here, the true specific gravity of the toner was measured using an air comparison type densitometer 930 type (manufactured by Beckman Japan KK).

In particular, the metal material used as the colorant is
It has been found that the above-mentioned drawbacks can be improved by incorporating a compound of each element selected from Mn, Ti, Cu, Si and C, or an oxide thereof, or a mixture thereof. Here, the content of Mn, Ti, and Cu is appropriately selected in order to obtain necessary magnetic characteristics and color characteristics, and it is important in the present invention to contain these metals or metal oxides. .

In particular, the metal particles used as the colorant have the shortest average particle diameter of 0.01 to 0.8 μm, preferably 0.02 to 0.5 μm, which is the best in terms of color characteristics. Here, when the average particle size is less than 0.01 μm,
The dispersibility in the binder resin deteriorates and the fixing characteristics deteriorate,
When the average particle diameter exceeds 0.8 μm, there have been problems such as insufficient coloring.

The content of the compound used as the colorant of this toner is 5 to 100 parts by weight of the binder resin.
It is preferably 40 parts by weight, particularly preferably 1
It is 0 to 25 parts by weight. Here, when the amount is less than 5 parts by weight, the coloring power of the toner is lowered, and further, the polishing effect on the surface of the photoconductor is insufficient, so that filming easily occurs. When the amount is more than 40 parts by weight, There was also a problem that the dispersibility in the toner was deteriorated, the developing property was deteriorated due to the decrease in the charging property, and at the same time, the fixing property was deteriorated. Further, since the saturation magnetization and coercive force of the toner are increased, the fluidity of the toner is reduced, and the magnetic binding force on the developing sleeve is increased, which causes problems such as damage to the photoconductor. It was

The resin constituting the toner is not particularly limited as long as it is a toner of the above-mentioned conditions, and various resins can be applied as will be described later, but a polyester resin has a low temperature fixing property in particular. It is preferable from the point.

The particle size of the toner of the present invention is not particularly limited, but the volume average particle size is preferably 2.5 to 10 μm in order to obtain high image quality excellent in fine line reproducibility and the like. In particular, when a hard metal material having a high specific gravity as used in the present invention is contained in the toner, the stress concentration portion is at the interface between the resin and the metal material due to the difference in hardness with the resin at the time of pulverization during toner production. The particles are easily formed and crushed, and the particle size of the toner is easily reduced. Therefore, high image quality is easily obtained.

The toner volume average particle diameter can be measured by various methods. In the present invention, Coulter Counter TAII manufactured by Coulter Electronics Co., USA is used. The method for producing the toner of the present invention is not limited, and may be an ordinary pulverization method, a production method other than the pulverization method such as a polymerization method, or a combination thereof.

Next, the materials used for the toner of the present invention will be described in detail. The polyester resin used in the present invention is usually obtained by polycondensation of alcohol and carboxylic acid. Examples of the alcohol include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol, etherified bisphenols such as 1.4-bis (hydroxymethyl) cyclohexane, and bisphenol A, and other divalent alcohols. And polyhydric alcohol monomers having a valence of 3 or more can be mentioned.

The carboxylic acid is, for example, a divalent organic acid monomer such as maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid or malonic acid,
1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, 1,
Examples thereof include trivalent or higher polyvalent carboxylic acid monomers such as 2,7,8-octanetetracarboxylic acid. here,
As the polyester resin, those having a glass transition temperature Tg of 55 ° C. or higher, and more preferably 60 ° C. or higher are preferable from the viewpoint of heat storability.

In the present invention, the polyester resin is most suitable as the resin component in the toner as described above, but resins other than the polyester resin may be used alone or in a blend as long as the toner molecular weight distribution is satisfied. A low temperature fixing can be achieved in use. Further, even when the polyester resin is used, another resin may be used in combination as long as the performance of the toner is not impaired.

Examples of usable resins other than polyester resins include the following. It should be noted that these resins are not limited to being used alone, but may be used in combination of two or more kinds. Polystyrene, chloropolystyrene, poly α-methylstyrene, styrene / chlorostyrene copolymer, styrene / propylene copolymer, styrene / butadiene copolymer, styrene / vinyl chloride copolymer, styrene / vinyl acetate copolymer, styrene / Maleic acid copolymer, styrene / acrylic acid ester copolymer
(Styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer, styrene / phenyl acrylate copolymer, etc.), styrene /
Methacrylate copolymers (styrene / methyl methacrylate copolymers, styrene / ethyl methacrylate copolymers, styrene / butyl methacrylate copolymers, styrene / phenyl methacrylate copolymers, etc.), styrene / α-
Styrene resins such as methyl chloroacrylate copolymer, styrene / acrylonitrile / acrylic ester copolymer (homopolymer or copolymer containing styrene or styrene substitute), vinyl chloride resin, styrene / vinyl acetate copolymer Coal, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene / ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, petroleum-based Resin, hydrogenated petroleum resin. The method for producing these resins is not particularly limited, and any of bulk polymerization, solution polymerization, emulsion polymerization and suspension polymerization can be used. Further, the glass transition temperature Tg of the above-mentioned resin is preferably 55 ° C. or higher, more preferably 60 ° C. or higher in view of the heat preservation property, like the polyester resin.

As the black colorant used for the surface treatment of the metal oxide of the present invention, several dyes and pigments such as dyes and pigments such as carbon black, lamp black, iron black, aniline black, graphite and fullerene are used. A dye / pigment / compound that produces a black color, and any conventionally known black dye / pigment can be used alone or in combination.

As the release agent used in the toner of the present invention, all known release agents can be used, and in particular, free fatty acid type carnauba wax, montan wax and oxidized rice wax can be used alone or in combination. . As the carnauba wax, fine crystalline one is preferable, an acid value of 5 or less, and a particle diameter of 1 μm or less when dispersed in a toner binder are preferable. The montan wax generally refers to a montan wax purified from minerals, and like carnauba wax, it is preferably microcrystalline and has an acid value of 5 to 14. The oxidized rice wax is obtained by air-oxidizing rice bran wax, and its acid value is preferably 10 to 30.

As the other releasing agent, any conventionally known releasing agent such as solid silicone varnish, higher fatty acid higher alcohol, montan ester wax and low molecular weight polypropylene wax can be mixed and used. The amount of these release agents used is 1 to 20 with respect to the toner resin component.
Parts by weight, preferably 3 to 10 parts by weight.

The toner of the present invention may be blended with a charge control agent, a fluidity improving agent and the like, if necessary. As the charge control agent, any conventionally known polarity control agent such as salicylic acid metal complex, nigrosine dye, metal complex salt type dye, and quaternary ammonium salt can be used alone or in combination. The amount of these polarity control agents used is 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on the toner resin component. As the fluidity improver, any conventionally known fluidity improvers such as hydrophobic silica, titanium oxide, silicon carbide, aluminum oxide and barium titanate can be used alone or in combination, and particularly, hydrophobic silica or oxide Titanium is excellent in improving fluidity, stabilizing charging and improving recyclability. More preferably, good results can be obtained by using hydrophobic silica in combination with titanium oxide. The amount of these fluidity improvers used is 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, based on the weight of the toner.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The results of characteristic evaluation in each example are shown in Table-1. As the evaluation device, a modified machine of Mylicopy M-5 manufactured by Ricoh Co., Ltd. was used. All parts are parts by weight. For each characteristic evaluation, the average of the evaluation results at the start of each Example and after 1,000,000 sheets was shown based on the following evaluation results. Further, only in Example 4, the toner was obtained by removing the release agent, and the fixing portion was improved to the oil coating type.

A method for evaluating the characteristics of the toner prepared in each example will be described. (Evaluation device) Toner (7) is supplied to the developing device shown in FIG. In FIG. 1, (1) is a latent image carrier (photoreceptor),
(2) is a developing roller, (2-1) is a core metal, (2-2)
Is a resin coat layer, (3) is a toner supply member, (4) is a developer coating blade, (5) is an agitator, and (6) is a development area. Specifically, the developing roller (2) is
A core metal (2-1) is provided with a surface layer containing a silicone resin as a main component as a resin coat (2-2), and a toner supply roller (3) made of a polyurethane material that contacts the developing roller (2), Further, a blade (4) made of a urethane material that abuts on the developing roller (2) was set as shown in FIG. In addition, FIG. 1 shows a developing roller (2).
Shows the core metal (2-1) and the resin coating layer (2-2), the core metal (2-1) and the resin coating layer (2-
Instead of 2), a developing device entirely made of a metal material was used, but the same result was obtained. Although the developing roller has a magnet built therein, it is not limited to this.

1) A solid image having an image density of 1 mg / cm ² was prepared, and the image density at that time was measured using a Macbeth densitometer and evaluated according to the following 5 grades. Note that the image density of black toner using carbon black that is normally put on the market is a level of □. High ◎: Very high, ○: High, □: Normal, △: Low,
X: Very low Low 2) A white paper with a background stain is output in A3 size, the image densities at arbitrary 6 positions in the image are measured with a Macbeth reflection densitometer, and the ID is determined according to the following criteria. It carried out in five steps. It should be noted that the value in which there is no background stain is equivalent to the reflection density of the paper, and the larger the value, the worse the background stain. Good ◎: Very good, ○: Good, □: Normal, △: Bad
X: Very bad 3) Toner scattering The state of toner scattering inside the copying machine was evaluated according to the following 5 grades. The black toner using ordinary carbon black was set to the level of □. Good ◎: Very good, ○: Good, □: Normal, △: Bad
X: Very bad 4) Fine line reproducibility An image evaluation test was performed on each developer, and fine line reproducibility was evaluated on a scale of 5 according to the following criteria. Excellent: ◎, Good: ○, □: Normal, △: Bad, ×: Worst

[0037]

EXAMPLE Next, an example of manufacturing the surface-treated black magnetic material used in this example will be described. This can be obtained by a known surface treatment means, but is not limited to this.

(Metal Oxide Production Example 1) Mn-containing maghemite particles (saturation magnetization 15 emu / g, average particle size 0.28)
The surface-treated metal oxide 1 was obtained by immobilizing aniline black on the particle surface using 8% by weight Mechanomill (manufactured by Okada Seiko) or Mechanofusion System (manufactured by Hosokawa Micron).

(Metal Oxide Production Example 2) Magnetite particles (saturation magnetization 72 emu / g, average particle diameter 0.25 μm)
Aniline black was fixed to the surface of the particles using 8% by weight MechanoMill (manufactured by Okada Seiko) or Mechanofusion System (manufactured by Hosokawa Micron) to obtain a surface-treated metal oxide 2.

(Metal Oxide Production Example 3) Mn-containing hematite particles (saturation magnetization 0 emu / g, average particle size 0.25 μm)
An aniline black was fixed to m) using 8 wt% Mechanomill (made by Okada Seiko) or Mechanofusion System (made by Hosokawa Micron) to obtain surface-treated metal oxide 3.

(Examples 1 and 2) Polyester resin 80 parts by weight (monomer: PO / EO adduct of bisphenol A, terephthalic acid / trimellitic acid, Tg: 62 ° C) Polyethylene-styrene / acrylic graft copolymer 20 parts by weight Parts (SP value: 9.0, monomers: polyethylene, styrene, methyl acrylate) Defreeized fatty acid type carnauba wax (melting point 83 ° C., penetration degree 0.5) 5 parts by weight Metal salt of salicylic acid derivative 2 parts by weight carbon Black (# 44 manufactured by Mitsubishi Carbon Co., Ltd.) 3 parts by weight Black metal oxide 1 22 parts by weight After thoroughly mixing the above materials with a blender, kneading with a twin-screw extruder, cooling and pulverizing and classifying to obtain a base toner It was
To the resulting toner base, 0.6 wt% of hydrophobic silica and 0.3 wt% of titanium oxide were added and mixed to obtain a final toner, and each evaluation was performed.

(Comparative Example 1) Black metal compound 1 of Example 1
A toner was obtained in the same manner as in Example 1 except that was changed to Black Metal Compound 2.

(Comparative Example 2) Black metal compound 1 of Example 1
A toner was obtained in the same manner as in Example 1, except that was changed to Black Metal Compound 3.

(Comparative Example 3) Black metal compound 1 of Example 1
A toner was obtained in the same manner as in Example 1 except that 100 parts by weight was used.

(Comparative Example 4) Black metal compound 1 of Example 1
Except for 18 parts by weight of carbon black,
A toner was obtained in the same manner as in Example 1.

Example 3 A toner was obtained in the same manner as in Example 1 except that the carbon black of Example 1 was removed and the black metal compound 1 was changed to 25 parts by weight.

(Example 4) A toner was obtained in the same manner as in Example 3, except that the releasing agent in Example 3 was omitted.

(Example 5) The carnauba wax of Example 1 was used as a low molecular weight polypropylene (Viscole 550P:
A toner was obtained in the same manner as in Example 1 except that the toner was changed to Sanyo Kasei.

(Example 6) Black metal compound 1 of Example 3
Of the maghemite particles (saturation magnetization 14 emu / g, average particle size 0.25
The toner was obtained in the same manner as in Example 1 except that the toner was changed to μm).

[0050]

[Table 1]

[0051]

As is clear from the detailed and specific description above, according to the present invention, an image-forming toner capable of obtaining a good image without causing background stains and toner scattering even after long-term use. Therefore, it is possible to provide a container in which toner is stored and an image forming apparatus, which is an extremely excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view centering on a developing roller section showing an example of a developing device useful for using the toner of the present invention.

[Explanation of symbols]

1 Latent image carrier (belt photoreceptor) 2 Developing roller (metal roller) 2-1 Core bar 2-2 Resin coat layer 3 Toner supply member 4 Developer coating blade 5 agitator 6 Development area 7 toner

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 9/087 G03G 9/08 331 (72) Inventor Toyoshi Sawada 1-3-6 Nakamagome, Ota-ku, Tokyo No. Ricoh Company (72) Inventor Yoichiro Watanabe 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company (72) Masahide Yamashita 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Company (72) Inventor Akihiro Koban 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Keiko Shiraishi 1-3-3 Nakamagome, Ota-ku, Tokyo F-term, Ricoh Co., Ltd. (Reference) 2H005 AA01 AA03 AA06 AA08 CA08 CA14 CA21 CB03 CB07 CB13 CB18 EA02 EA05 EA07 EA10 FA06

Claims (13)

[Claims] 1. Particles containing at least a binder resin and a colorant, and the colorant is a metallic material blackened by surface treatment with a pigment and / or a dye or a metallic material itself black, and saturated magnetization Value 0.01-3e
mu / g or less and true specific gravity of 1.33 to 1.62 g / c
A one-component toner for electrostatic charge development, which is in the range of m ³ . 2. The toner contains 0.01 to 5 parts by weight of a coloring agent.
The one-component toner for electrostatic charge development according to claim 1, which contains carbon black in an amount of wt%. 3. The saturation magnetization of the toner is 0.01 to 2 em.
3. The one-component toner for electrostatic charge development according to claim 1, which is u / g. 4. The true specific gravity of the toner is 1.40 to 1.55.
The one-component toner for electrostatic charge development according to claim 1, wherein the one-component toner is g / cm ³ . 5. A black metallic material used as a colorant,
At least Mn, T in hematite or maghemite
a compound of each element selected from i, Cu, Si and C,
Alternatively, the one-component toner for electrostatic charge development according to any one of claims 1 to 4, further comprising an oxide thereof or a mixture thereof. 6. The electrostatic charge development according to claim 1, wherein the black metal material used as the colorant has a short-sided average particle diameter of 0.01 to 0.8 μm. One-component toner for use. 7. An inorganic fine powder is used as an external additive, and the inorganic fine powder is at least one silica and / or titanium oxide.
The one-component toner for electrostatic charge development according to item 1. 8. The one-component toner for electrostatic charge development according to claim 1, wherein the binder resin is at least one polyester resin. 9. The one-component toner for electrostatic charge development according to claim 1, wherein the toner contains a release agent. 10. The one-component toner for electrostatic charge development according to claim 9, wherein the releasing agent is at least one of free fatty acid type carnauba wax, montan wax and oxidized rice wax. 11. The volume average particle diameter of the toner is 2.5 to 10.
The one-component toner for electrostatic charge development according to any one of claims 1 to 10, wherein the toner has a particle size of μm. 12. A toner container filled with the electrostatic charge developing toner according to claim 1. Description: 13. An image forming apparatus equipped with the toner container according to claim 12.