JPH06266154A - Developer - Google Patents

Abstract

PURPOSE:To provide the developer with which inorg. particulates are hardly embeddd into the surfaces of coloring particles without being made into thin layer by a developer layer regulating member in the developer contg. at least irregular-shaped coloring particles having relatively small grain sizes and the inorg. particulates. CONSTITUTION:The developer to be used in a developing method, in which the layer of the developer stuck onto a developer transporting and carrying member is made thin by a developer layer regulating member, then the developer is transported to a developing region and the electrostatic latent image is developed on a latent image carrying member by the developer layer, which has been made thin, contains at least the irregular-shaped coloring members having 2 to 10mum volume average grain sizes and the inorg. particulates having 5 to 10nm primary particle sizes. The surfaces of the irregular-shaped coloring particles are hardened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a developer carrying carrier, which is made thin by a developer layer regulating member and then carried to a developing area, where the developer layer is made thinner. ,
The present invention relates to a developer used in a developing method for developing an electrostatic latent image on a latent image carrier.

[0002]

2. Description of the Related Art In a developing method (a contact developing method and a non-contact developing method) for developing an electrostatic latent image on a latent image bearing member by a developer layer on a developer carrying member, the charge amount distribution of the developer is changed. From the viewpoint of improving the developability as a sharp object, the developer conveyed to the developing area is thinned to about 20 to 500 μm by a developer layer regulating member. Such a thin layer forming method has been proposed. (1) A non-contact thin layer two-component developing method used for forming a multicolor image by superposing color toner images on a latent image carrier (hereinafter also referred to as “photoreceptor”). (2) A thin-layer magnetic one-component developing method suitable for improving the triboelectric charging property of the magnetic toner with the developing sleeve and preventing the triboelectric charging between the magnetic toners. (3) A thin-layer non-magnetic one-component developing method in which only the non-magnetic toner is thinned and conveyed to the developing area for development.

As a developer layer regulating member for the above-mentioned thin layer forming method, a magnetic blade, a magnetic pressure regulating rod or the like is used in a developing device incorporating a magnetic mag roll, and thin layer non-magnetic single component development is performed. In the case of the method, a sponge roller, a flexible pressure regulating plate (stainless steel plate, phosphor bronze plate), or the like is used.

However, in the above-described thin layer forming method, the surface of the colored particles constituting the developer is heated and softened due to excessive stress such as shear stress applied to the developer by the developer layer regulating member. However, there is a problem that the external additive existing on this surface is buried in the colored particles. As a result, sufficient durability as a developer is not exhibited, and a problem that the constituent material of the developer adheres to the surface of the developer transport carrier (developing sleeve) occurs.
When the developer is a two-component developer including toner and carrier, spent on the carrier is generated.

On the other hand, in recent years, a toner having a small particle diameter has been used for the purpose of forming a high quality copied image, and a polymerization method is a suitable method for producing such a toner having a small particle diameter. Is proposed. Further, from the viewpoint of improving the cleaning property, a method for producing an amorphous polymerized toner by associating resin fine particles (association polymerization method) has been proposed (see JP-A-63-186253).

However, in the toner having a small particle diameter obtained by the above-mentioned (association) polymerization method, the heat capacity of the toner particles (coloring particles) itself is small, so that the external additive is buried during thinning. Is especially likely to occur. In addition, the amorphous polymerized toner obtained by the association polymerization method may be crushed when it is thinned.

As a means for preventing the embedding of the external additive and improving the durability of the developer against such problems,
It has been proposed to externally add inorganic fine particles having a large particle size (see JP-A-57-179866).

However, the inorganic fine particles having a large particle size (for example, about 150 μm) cannot sufficiently exhibit the effect of improving the chargeability and the effect of improving the fluidity required for the external additive. For this reason, the toner is likely to be scattered, and in the two-component developing method, the inorganic fine particles having a large particle size may migrate to the carrier to reduce the charge amount. Further, in the non-magnetic one-component developing method, the flexible developing sleeve may be scratched by the large-sized inorganic fine particles, and white streaks or the like may be generated in the obtained copied image.

[0009]

SUMMARY OF THE INVENTION The present invention has been made under the circumstances described above, and a first object of the present invention is to provide irregular colored particles having a relatively small particle size, A developer containing at least inorganic fine particles (external additive) is to provide a developer in which the inorganic fine particles are less likely to be buried in the surface of the colored particles even when the developer is thinned by the developer layer regulating member. . A second object of the present invention is to provide a developer capable of suppressing / preventing adhesion of a toner substance to the surface of a developing sleeve. Third of the present invention
The purpose of is to provide a developer that does not generate spent on the carrier when the developer is a two-component developer containing a carrier.

[0010]

The developer of the present invention is formed into a thin layer by transporting the developer adhered on the developer transport carrier to a developing area after being thinned by a developer layer regulating member. In the developer used in the developing method for developing the electrostatic latent image on the latent image carrier by the developer layer, the irregular colored particles having a volume average particle diameter of 2.0 to 10.0 μm At least inorganic fine particles having a particle diameter of 5 to 100 nm are contained, and the surface of the irregular shaped colored particles is hardened.

Further, the developer of the present invention contains amorphous colored particles obtained by curing the surface of the amorphous associated particles obtained by associating the resin fine particles in the presence of the colorant, by a crosslinking reaction. Preferably.

Further, the developer of the present invention preferably contains irregularly shaped colored particles having a cured outer wall formed by an interfacial polymerization method involving a crosslinking reaction.

[0013]

[Action]

(1) The irregular-shaped colored particles constituting the developer of the present invention are
The surface is hardened. Therefore, the thermal characteristics of the surface of the colored particles are improved, and the softening of the surface is suppressed even by the heat generated when the layer is thinned, thereby preventing the inorganic fine particles as the external additive from being buried. (2) Since the inorganic fine particles are prevented from being buried in the surface of the colored particles, the durability as a developer is improved, and the adhesion of the toner substance to the surface of the developing sleeve and the spent on the carrier are effectively prevented. You can

The present invention will be described in detail below. The developer of the present invention contains at least irregular colored particles and inorganic fine particles as an external additive.

[Colored Particles] The colored particles constituting the developer of the present invention are irregularly shaped particles whose surface is hardened.

In this specification, the hardened "surface of the colored particles" includes a range of at least a depth of 5 nm and at most a depth of not more than 200 nm. The reason for this is that when uncured colored particles were taken with a transmission electron microscope (TEM), a cross-sectional photograph was taken to observe the burial state of the inorganic fine particles. The reason for this is that inorganic fine particles are observed, and as a result, it was considered necessary to cure to a depth of at least 5 nm in order to achieve the object of the present invention. On the other hand, when it is hardened to a deep range of more than 200 nm, the thermal characteristics of the colored particles themselves are significantly changed, which may adversely affect the fixability and the like, which is not preferable.

The particle diameter of the colored particles is 2.0 to 10.0 μm in terms of volume average particle diameter measured by “Coulter Counter TA-II”, preferably 3.0 to 7.
It is set to 0 μm. The colored particles having a volume average particle size of 10.0 μm or less have a small heat capacity, and therefore, the external additive is particularly likely to be buried when the layer is thinned.
The present invention improves the durability of a developer containing such small-sized colored particles. However, when the surface of the colored particles having a volume average particle diameter of less than 2.0 μm is cured, the thermal characteristics of the entire colored particles may change, and the fixability may be impaired.

The developer of the present invention is characterized in that the surface of the irregular colored particles constituting the developer is hardened. Such colored particles can be prepared by "surface cross-linking of irregularly-shaped associated particles" and "formation of cross-linked cured outer wall by interfacial polymerization method" described in detail below.

[Surface Crosslinking of Amorphous Association Particles] In this preparation method, resin particles forming a binder resin are associated with each other in the presence of a colorant to obtain amorphous association particles. It is a method of curing by a crosslinking reaction.

An example of a specific method for preparing such colored particles will be described. (1) First, the average particle size is 0.1 to 2.
A resin fine particle of 0 μm is prepared. Here, the monomer component for forming the resin fine particles is not particularly limited, but it is necessary to contain a monomer (reactive substituent-containing monomer) for introducing a reactive substituent involved in the crosslinking reaction described later. There is. Examples of the reactive substituent-containing monomer include epoxy group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers and the like.
When the resin fine particles are prepared, their softening point T
sp (refers to a temperature measured by a Koka type flow tester; the same applies hereinafter) is in the range of 100 to 150 ° C., glass transition point Tg (refers to a temperature measured by DSC).
It is preferable from the viewpoint of the fixability and storability of the developer that the monomer composition (for example, styrene-acrylic type is suitable) and the polymerization reaction conditions are selected so that the same will be applied in the following) is in the range of 45 to 70 ° C. .

(2) When the polymerization conversion rate of the resin fine particles reaches 80% or more, a coloring agent such as a pigment is added and the system (aqueous phase) is heated with stirring. As a result, the resin fine particles are associated with each other while taking in the colorant, and the irregularly-shaped associated particles containing the colorant and having a volume average particle size of 2.0 to 10.0 μm can be obtained. The colorant contained in the irregular-shaped associated particles is not particularly limited, and all dyes, pigments and the like used as conventional colorants for toner can be used.

(3) Next, the surface of the obtained irregularly-shaped associated particles is cured by a crosslinking reaction. The reactive substituents, which are hydrophilic groups, are oriented on the surface of the irregularly-shaped associated particles in the aqueous phase. Therefore, a polyfunctional compound capable of reacting with the reactive substituent is added to the aqueous phase to cause a crosslinking reaction on the surface of the irregularly-shaped associated particles to form a hardened surface layer. The surface layer formed by the cross-linking reaction includes a cured epoxy resin layer formed by a reaction between an epoxy group (reactive substituent) and a polyvalent amine (polyfunctional compound), a carboxyl group (reactive substituent) and a polyhydric alcohol ( Examples thereof include a cured polyester resin layer formed by a reaction with a polyfunctional compound) and a cured epoxy resin formed by a reaction between an amino group (reactive substituent) and a polyvalent epoxy compound (polyfunctional compound). The curing depth (thickness of the surface layer) can be adjusted by controlling the permeation rate of the polyfunctional compound.

[Formation of cross-linked cured outer wall by interfacial polymerization method]
This preparation method, first, to form a cured outer wall by an interfacial polymerization method involving a cross-linking reaction, and then polymerize the monomer component of the interior partitioned by the cured outer wall, a cured outer wall (crosslinked polymer), This is a method for obtaining irregularly shaped colored particles composed of a core material (polymer). Here, the interfacial polymerization method is one in which a polymerizable monomer is added to each of two liquid phases (oil phase / water phase) that are incompatible with each other, and a polymerization reaction is performed at the interface between the oil phase and the water phase. Forming a polymer film that is insoluble in the liquid phase.

An example of a specific method for preparing such colored particles will be shown. (1) First, radically polymerizable monomer (for forming core material)
, A radical polymerization initiator, a colorant, and an oil-soluble interfacial polymerizable monomer (a polyfunctional monomer for forming a cured outer wall) are mixed, and the oil-soluble monomer mixture is dispersed / suspended in an aqueous dispersion medium. , Prepare an aqueous reaction system dispersed in a predetermined particle size.

(2) A water-soluble interfacial polymerizable monomer for forming a cured outer wall is added to the prepared aqueous reaction system to cause an interfacial polymerization reaction accompanied by a crosslinking reaction at a low temperature (below the radical polymerization temperature). This surrounds the core-forming component,
A cross-linked cured outer wall is formed.

(3) Next, the temperature of the aqueous reaction system is heated to the radical polymerization temperature to polymerize the radically polymerizable monomer to form a core material. In this process, the volumetric shrinkage occurs due to the polymerization of the radical-polymerizable monomer, so that folds are formed on the cured outer wall, and the colored particles obtained are indefinite.

In the above-mentioned method for preparing colored particles (formation of cross-linked cured outer wall by interfacial polymerization method), a vinyl-based monomer can be preferably used as the radically polymerizable monomer for forming the core material, for example, acetic acid. vinyl,
Styrene, p-methylstyrene, p-tert-butylstyrene, p-methoxystyrene, 3,4-dichlorostyrene, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, acrylic acid n-octyl, 2-ethylhexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, lauryl methacrylate, stearyl methacrylate, phenyl methacrylate, N-vinylpyrrolidone, N-vinylindole, etc. You can

Of these radically polymerizable monomers, a styrene-based monomer and an acrylic-based monomer are used in combination,
It is preferable to form a core material made of styrene-acrylic resin. Regarding the resin that constitutes the core material, the ratio “Mw / Mn” of the weight average molecular weight Mw and the number average molecular weight Mn.
The value of is preferably 4.0 to 60. Where M
The values of w and Mn shall mean the values measured by GPC (the same applies below). The softening point Tsp of the resin constituting the core material is 100 to 150 ° C.
And the glass transition point Tg is preferably in the range of 10 to 60 ° C.

Acid chlorides, epoxy compounds, isocyanates and the like can be used as the oil-soluble interfacial polymerizable monomer for forming the cured outer wall.

Examples of the acid chloride include sebacic acid dichloride, isophthalic acid dichloride, m-benzenedisulfonyl chloride and the like.

As the epoxy compound, for example, a bisphenol A type epoxy compound represented by the following chemical formula 1 [commercial product name: "Epicoat 801", "Epicoat 815",
"Epicoat 819", "Epicoat 828", "Epicoat 834" (manufactured by Yuka Shell Epoxy Co., Ltd.)], a resorcin-type epoxy compound represented by the following Chemical formula 2, a bisphenol F-type epoxy compound represented by the following Chemical formula 3 and the like can be mentioned. . In the following chemical formulas 1 to 3, n represents an integer of 0 or more.

[0032]

[Chemical 1]

[0033]

[Chemical 2]

[0034]

[Chemical 3]

As the isocyanate, for example, hexamethylene diisocyanate represented by the following chemical formula 4 [commercial product name: "Sumijour H" (manufactured by Sumitomo Bayer Urethane Co.)], an isocyanate compound represented by the following chemical formula 4 [commercial product name: "Sumi" Joule N ”(manufactured by Sumitomo Bayer Urethane Co., Ltd.)], metaphenylene diisocyanate represented by the following chemical formula 4 [commercial product name:“ NAFCONATE ”(manufactured by National Aniline Co.)], and toluylene diisocyanate represented by the following chemical formula 4 (commercial product name:“ Seminar 80 "
(Manufactured by Sumitomo Chemical Co., Ltd.), “HIREN ™” (manufactured by DuPont)], 2,4-tolylene diisocyanate represented by the following chemical formula 5 [commercial product name: “Sumijour T” (manufactured by Sumitomo Bayer Urethane Co.)], Reaction product of toluylene isocyanate and trimethylolpropane represented by the following chemical formula 5 [commercial product name: "Sumijour L" (Sumitomo Bayer Urethane Co., Ltd.), "Coronate L" (Nippon Polyurethane Industry Co., Ltd.)] 3,3'-dimethyl-diphenyl-4,4'-diisocyanate represented by 6 [commercial product name: "HIREN H" (manufactured by DuPont), "Suminate BT" (manufactured by Sumitomo Chemical Co., Ltd.)] The indicated diphenylmethane-4,4'-diisocyanate [commercial product name: "Millionate MT" (manufactured by Nippon Polyurethane Industry Co., Ltd.)], represented by the following chemical formula 6 That 3,3'-dimethyl - diphenylmethane-4,4'-diisocyanate [a commercial name: "Hairen DMM" (manufactured by EI du Pont de Nemours and Company)],
Triphenylmethane-triisocyanate represented by the following chemical formula 7 [commercial product name: "Sumijour R" (manufactured by Sumitomo Bayer Urethane Co.)], polymethylene phenyl isocyanate represented by the following chemical formula 7 [commercial product name: "Millionate MR" (Japan Polyurethane Industry Co., Ltd.)]
Naphthalene-1,5-diisocyanate [commercial product name: "Sumijour 15" (manufactured by Sumitomo Bayer Urethane Co.)], and other commercially available polyisocyanates such as "Sumijour 44V10" and "Desmodur V"
K "," SBU Isocyanate 0389 "(above, Sumitomo Bayer Urethane Co., Ltd.)," Coronate HL "," Coronate 3041 "," Coronate 2014 "," Millionate MR-400 "(above, Nippon Polyurethane Industry Co., Ltd.), "Dupolanate 24A-90cx" (manufactured by Asahi Kasei Kogyo Co., Ltd.) and the like.

[0036]

[Chemical 4]

[0037]

[Chemical 5]

[0038]

[Chemical 6]

[0039]

[Chemical 7]

As the water-soluble interfacial-polymerizable monomer forming the cured outer wall by the interfacial polymerization reaction with the oil-soluble interfacial-polymerizable monomer, for example, a polyol compound, a polyamine compound or the like can be used.

Examples of the polyol compound include diols such as ethylene glycol, propylene glycol, butylene glycol and hexamethylene glycol, glycerin, trimethylolpropane, trimethylolethane, triols such as 1,2,6-hexanetriol, and pentane. Erythritol, water and others.
Then, for example, a cured outer wall made of a cured urethane resin is formed by an interfacial polymerization reaction of the above-mentioned polyol compound and isocyanate (oil-soluble interfacial polymerizable monomer).

As the polyamine compound, ethylenediamine, hexamethylenediamine, diethylenetriamine, iminobispropylamine, phenylenediamine,
Examples include xylylenediamine, triethylenetetramine, and the like. Then, for example, a cured outer wall made of a cured urea resin is formed by an interfacial polymerization reaction of the above polyamine compound and isocyanate (oil-soluble interfacial polymerizable monomer).

The colorant used in this preparation method is not particularly limited, and any of the dyes and pigments conventionally used as colorants for toner can be used.

In this preparation method, the oil-soluble monomer mixture is emulsified and dispersed in an aqueous dispersion medium, but a dispersion stabilizer is mixed in the aqueous dispersion medium in order to prevent aggregation of particles. There is a need.

Examples of such dispersion stabilizers include water-soluble polymer substances such as gelatin, gelatin derivatives, polyvinyl alcohol, polystyrene sulfonic acid, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium carboxymethyl cellulose and sodium polyacrylate. , Anionic surfactants, nonionic surfactants, surfactants such as cationic surfactants, colloidal silica, alumina,
Hydrophilic inorganic colloidal substances such as tricalcium phosphate, ferric hydroxide, titanium hydroxide, aluminum hydroxide and the like can be effectively used. These dispersion stabilizers can be used alone or in admixture of two or more.

The colored particles prepared as described above may contain waxes such as low molecular weight polyethylene, paraffin wax and carnauba wax, and a releasing agent such as silicone oil.

[Inorganic Fine Particles] The developer of the present invention is composed of the irregular shaped colored particles prepared as described above and the inorganic fine particles as an external additive.

The inorganic fine particles are not particularly limited, and all those used as the external additive of the toner can be used.

The content ratio (addition amount) of the inorganic fine particles varies depending on the particle size of the colored particles, but is usually 1 to 5% by weight. If the content ratio of the inorganic fine particles is too large, problems such as migration of the inorganic fine particles to the carrier, adhesion to the photoconductor, and damage to the cleaning blade may occur.

The primary particle diameter of the inorganic fine particles is usually 5
-100 nm, preferably 7-50 nm. When the primary particle diameter of the inorganic fine particles is less than 5 nm, the inorganic fine particles themselves are likely to aggregate, and further, the adhesive force to the colored particles is large, so that the fluidity imparting effect is not exhibited. On the other hand, when the primary particle size exceeds 100 nm, the effect of improving the charging property and the effect of improving the fluidity cannot be sufficiently exerted, and toner scattering tends to occur during image formation, and the two-component developing method is also effective. In some cases, the inorganic fine particles may migrate to the carrier to reduce the charge amount. Further, in the non-magnetic one-component developing method, the flexible developing sleeve is scratched by the large-sized inorganic fine particles to obtain a copy image. It is not preferable because white stripes may be generated.

By including the inorganic fine particles as an external additive, the chargeability and fluidity of the developer can be improved. Then, even when the developer is thinned, since the inorganic fine particles are not buried in the surface of the colored particles, the above-described charging property improving effect and fluidity improving effect will be exhibited for a long period of time. .

The developer of the present invention contains a toner composed of the irregular colored particles and the inorganic fine particles as an essential component. The developer of the present invention includes a two-component developer including a non-magnetic toner containing no magnetic material and a carrier, a magnetic one-component developer including a magnetic toner containing a magnetic material, and a non-magnetic toner containing no magnetic material. It can be used as any of the non-magnetic one-component developers made of toner.

The carrier constituting the two-component developer is not particularly limited, but a ferrite carrier is preferable, and in particular, a resin-coated carrier in which the surface of core material particles is coated with styrene-acrylic resin or the like. Is preferred. The volume average particle size of the carrier is, for example, about 20 to 100 μm.

[Thin Layer Forming Method] The developer of the present invention is formed into a thin layer by thinning the developer deposited on the developer carrying carrier to about 20 to 500 μm by the developer layer regulating member. It is used in a developing method of transporting an agent layer to a developing area to develop an electrostatic latent image on a latent image carrier.

The following methods can be mentioned as the developing method involving formation of a thin layer. (1) A thin-layer two-component developing method for the above two-component developer, in which the thickness of the developer layer is regulated by a pressure regulating member such as a magnetic rod. (2) A thin-layer magnetic one-component developing method for the above magnetic one-component developer, wherein the thickness of the developer layer is regulated by a pressure regulating member composed of a magnetic blade or a magnetic rod. (3) A thin-layer non-magnetic one-component developing method in which the thickness of the developer layer is regulated with respect to the above-mentioned non-magnetic one-component developer by a pressure regulating member composed of an elastic blade (for example, urethane, stainless steel, phosphor bronze). In addition, the pressing force by the pressing restriction member is usually 2 to 1
It is set to about 5 gf / mm.

[0056]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to these. In the following, "part" means "part by weight". Also,
The volume average particle size of the colored particles is “Coulter Counter TA
-II ".

<Preparation Example of Colored Particles by Surface Cross-Linking of Amorphous Association Particles> [Preparation Example A1] Polyoxymethylene alkyl ether 1
Parts, 1.5 parts of sodium alkylbenzene sulfonate and 0.5 parts of potassium persulfate were dissolved in 100 parts of water.
To this aqueous solution, a monomer mixture consisting of 80 parts of styrene, 15 parts of 2-ethylhexyl acrylate, and 5 parts of acrylic acid (reactive substituent-containing monomer) was added dropwise with stirring to emulsify. This emulsification reaction system was heated to 65 ° C. and polymerized for 8 hours to generate resin fine particles having a volume average particle diameter of 0.3 μm. To 200 parts of an emulsion containing the resin fine particles, 5 parts of carbon black,
400 parts of water and 1 ethylene glycol (polyfunctional compound)
A mixed solution with 0 parts was added, and dispersion stirring was performed with a slasher at a temperature of 30 ° C. After the lapse of 2 hours, microscopic observation of this system was performed, and it was confirmed that the association of the resin fine particles formed the amorphous associated particles containing the colorant. Then, by heating the system to 85 ° C. and maintaining the stirring for 5 hours,
The surface of the amorphous associated particles was cured by a crosslinking reaction.
Then, after cooling this system, the dispersion was filtered, washed with water and dried to obtain surface-cured irregularly shaped colored particles (for the present invention). The volume average particle size of the colored particles (hereinafter referred to as “colored particles A1”) was measured to be 5.6.
was μm.

Preparation Example A2 Preparation Example A1 except that glycidyl methacrylate was used instead of acrylic acid and diethylenetriamine was used instead of ethylene glycol.
In the same manner as in (1) to (4), surface-cured irregularly-shaped colored particles (for the present invention) were obtained. This colored particle (hereinafter "colored particle A2")
It was 5.7 μm.

[Preparation Example A3] Irregular shaped colored particles whose surface was hardened in the same manner as in Preparation Example A1 except that 60 parts of magnetite powder (primary particle diameter = 0.2 μm) was used in place of carbon black. (For the present invention) was obtained. The volume average particle diameter of the colored particles (hereinafter referred to as “colored particles A3”) was measured and found to be 5.3 μm.

[Preparation Example A4] Irregular shaped colored particles having a hardened surface in the same manner as in Preparation Example A2 except that 60 parts of magnetite powder (primary particle diameter = 0.2 μm) was used in place of carbon black. (For the present invention) was obtained. The volume average particle diameter of the colored particles (hereinafter referred to as “colored particle A4”) was measured and found to be 5.6 μm.

[Comparative Preparation Example a1] Amorphous colored particles (for comparison) were obtained in the same manner as in Preparation Example A1 except that ethylene glycol was not used. The volume average particle diameter of the colored particles (hereinafter referred to as “colored particles a1”) was measured and found to be 5.5 μm.

[Comparative Preparation Example a2] Amorphous colored particles (for comparison) were obtained in the same manner as in Preparation Example A2 except that diethylenetriamine was not used. The volume average particle diameter of the colored particles (hereinafter referred to as “colored particles a2”) was measured and found to be 5.6 μm.

[Comparative Preparation Example a3] Amorphous colored particles (for comparison) were obtained in the same manner as in Preparation Example A3 except that ethylene glycol was not used. The volume average particle diameter of the colored particles (hereinafter referred to as “colored particles a3”) was measured and found to be 5.5 μm.

[Comparative Preparation Example a4] Amorphous colored particles (for comparison) were obtained in the same manner as in Preparation Example A4 except that diethylenetriamine was not used. The volume average particle diameter of the colored particles (hereinafter referred to as “colored particles a4”) was measured and found to be 5.6 μm.

<Preparation Example of Colored Particles by Forming Cross-Linked Cured Outer Wall by Interfacial Polymerization Method> [Preparation Example B1] 130 parts of styrene [monomer for forming core material], 2-
Ethylhexyl acrylate [core forming monomer] 6
0 part, 15 parts of carbon black "Mogal L" (manufactured by Cabot Corporation), 5 parts of 2,2'-azobis (2,4-dimethylvaleronitrile) [polymerization initiator], and polymethylene phenyl isocyanate "Coronate L". 10 parts of (Sumitomo Bayer Urethane Co., oil-soluble interfacial polymerizable monomer) and 5 parts of an epoxy compound “Epicoat 819” (Okaka Shell Epoxy Co., oil-soluble interfacial polymerizable monomer)
An oil-soluble monomer mixture was obtained by mixing and dispersing with a sand stirrer. An aqueous colloidal solution containing 2% by weight of tricalcium phosphate [dispersion stabilizer] and 0.02% by weight of sodium dodecylbenzenesulfonate was prepared. The body mixture was added so that the solid content concentration was 15% by weight, and the mixture was dispersed / suspended by "TK Homogenter" (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare an aqueous reaction system. When the reaction system was observed with a microscope, dispersed particles (oil-soluble monomer mixture) of about 5 μm were confirmed. 8 parts of 1,6-hexamethylenediamine [water-soluble interfacial polymerizable monomer] was added to the aqueous reaction system prepared in (1), and the interfacial polymerization reaction was carried out at a temperature of 20 ° C. for 2 hours.
As a result, a cured outer wall made of the cured urea resin and the cured epoxy resin and surrounding the core material forming component was formed. Then, this system was heated at 60 ° C. for 8 hours to cause a radical polymerization reaction of the core material forming component. After 8 hours, it was cooled to 20 ° C. and hydrochloric acid was added to dissolve and remove tricalcium phosphate. Next, the dispersion was filtered from this system, washed with water and dried to obtain irregularly shaped colored particles (for the present invention) having a surface cured by a crosslinked outer wall. The volume average particle diameter of the colored particles (hereinafter referred to as “colored particles B1”) was measured and found to be 5.6 μm. Regarding the resin constituting the core material, the ratio “Mw / Mn” of the weight average molecular weight Mw to the number average molecular weight Mn was 7.0, the softening point Tsp was 121 ° C., and the glass transition point Tg was 43 ° C. .

[Preparation Example B2] Instead of polymethylene phenyl isocyanate, 5 parts of toluylene diisocyanate and "Sumijour L" (manufactured by Sumitomo Bayer Urethane Co.)
5 parts, and further, except that xylylenediamine was used in place of 1,6-hexamethylenediamine, in the same manner as in Preparation Example B1, irregularly shaped colored particles having a surface cured by a crosslinked outer wall ( (For the present invention). The volume average particle diameter of the colored particles (hereinafter referred to as “colored particle B2”) was measured and found to be 5.8 μm. Regarding the resin constituting the core material, the value of “Mw / Mn” was 7.0, the softening point Tsp was 121 ° C., and the glass transition point Tg was 43 ° C.

Preparation Example B3: Butyl acrylate was used in place of 2-ethylhexyl acrylate, and low molecular weight polypropylene “660P” (manufactured by Sanyo Kasei Co., Ltd.)
Amorphous colored particles (for the present invention) having a surface cured by a crosslinked outer wall were obtained in the same manner as in Preparation Example B1 except that 5 parts was added. This colored particle (hereinafter referred to as "colored particle B
3 ”) and the volume average particle diameter is measured to be 5.9 μm.
It was m. Regarding the resin that constitutes the core material, "M
The value of "w / Mn" was 6.0, the softening point Tsp was 119 ° C, and the glass transition point Tg was 38 ° C.

[Preparation Example B4] In the same manner as in Preparation Example B1 except that 90 parts of magnetite powder (primary particle size = 0.2 μm) was used in place of carbon black, an ink having a surface cured by a cross-linked outer wall was prepared. Regular colored particles (for the present invention) were obtained. The volume average particle diameter of the colored particles (hereinafter referred to as “colored particle B4”) was measured and found to be 5.5 μm. Regarding the resin that constitutes the core material, "Mw / M
The value of "n" was 7.0, the softening point Tsp was 121 ° C, and the glass transition point Tg was 43 ° C.

[Preparation Example B5] In the same manner as in Preparation Example B2 except that 90 parts of magnetite powder (primary particle size = 0.2 μm) was used in place of carbon black, an ink having a surface cured by a crosslinked outer wall was prepared. Regular colored particles (for the present invention) were obtained. The volume average particle diameter of the colored particles (hereinafter referred to as “colored particle B5”) was measured and found to be 5.7 μm. Regarding the resin that constitutes the core material, "Mw / M
The value of "n" was 7.0, the softening point Tsp was 121 ° C, and the glass transition point Tg was 43 ° C.

[Preparation Example B6] In the same manner as in Preparation Example B3 except that 90 parts of magnetite powder (primary particle size = 0.2 μm) was used in place of carbon black, an ink having a surface cured by a cross-linked outer wall was prepared. Regular colored particles (for the present invention) were obtained. The volume average particle diameter of the colored particles (hereinafter referred to as “colored particle B6”) was measured and found to be 5.6 μm. Regarding the resin that constitutes the core material, "Mw / M
The value of "n" was 6.5, the softening point Tsp was 118 ° C, and the glass transition point Tg was 39 ° C.

[Comparative Preparation Example b1] Styrene-butyl acrylate copolymer (composition ratio: St / BA = 75/25,
(Softening point Tsp: 130 ° C, glass transition point Tg = 53 ° C) 1
7.5 parts of carbon black "Mogal L" (manufactured by Cabot Corporation) was added to 00 parts and mixed, and the mixture was kneaded by a twin-screw extruder, and then pulverized and classified to have a volume average particle diameter of 5.5 μm. Colored particles (for comparison, hereinafter "colored particles b
1 ”).

[Comparative Preparation Example b2] Magnetite powder (primary particle size = 0.2 μm) 60 in place of carbon black
Colored particles having a volume average particle diameter of 5.5 μm (for comparison, hereinafter referred to as “colored particles b2”) were obtained in the same manner as in Comparative Preparation Example b1 except that parts were used.

<Examples 1 and 2 and Comparative Examples 1 and 2> Hydrophobic silica fine particles "R-972" (manufactured by Nippon Aerosil Co., Ltd., primary particle size =) are added to each of the colored particles A1 and A2 and the colored particles a1 and a2. 16 nm) was added and mixed at a ratio of 2.0% by weight to prepare a toner. Next, each of the produced toners is mixed with a carrier (average particle diameter of 60 μm) in which a resin coating layer made of styrene-acrylic resin is formed on the surface of ferrite particles, in a ratio such that the toner concentration is 7% by weight. Therefore, the developers 1-2 of the present invention
(Two-component developer) and comparative developers 1-2 (two-component developer) were produced.

<Examples 3 to 4 and Comparative Examples 3 to 4> For each of the colored particles A3 to A4 and the colored particles a3 to a4, hydrophobic silica fine particles "R-972" (manufactured by Nippon Aerosil Co., Ltd., primary particle size = 16 nm) is added and mixed at a ratio of 2.0% by weight to prepare the developer 3 to 4 of the present invention.
(Magnetic one-component developer) and Comparative developers 3 to 4 (magnetic one-component developer) were manufactured.

<Examples 5 to 6 and Comparative Examples 5 to 6> Hydrophobic silica fine particles "R-972" (manufactured by Nippon Aerosil Co., Ltd., primary particle size =) for each of the colored particles A1 to A2 and the colored particles a1 to a2. 16 nm) is added and mixed at a ratio of 2.0% by weight to obtain the developer of the present invention.
(Non-magnetic one-component developer) and Comparative Developers 5-6 (non-magnetic one-component developer) were produced.

<Examples 7 to 9 and Comparative Example 7> Hydrophobic silica fine particles "R-805" (manufactured by Nippon Aerosil Co., Ltd., primary particle size = 12 nm) were added to each of the colored particles B1 to B3 and the colored particle b1. A toner was prepared by adding and mixing in a ratio of 2.0% by weight. Next, each of the produced toners and a carrier having a resin coating layer made of styrene-acrylic resin formed on the surface of ferrite particles (average particle size 6
0 μm) was mixed in a ratio such that the toner concentration was 7% by weight to prepare Developers 7 to 9 (two-component developer) and Comparative Developer 7 (two-component developer) of the present invention.

<Examples 10 to 12 and Comparative Example 8> Hydrophobic silica fine particles "R-805" (manufactured by Nippon Aerosil Co., Ltd., primary particle diameter = 12 nm) were added to each of the colored particles B4 to B6 and the colored particle b2. The developers 10 to 12 (magnetic one-component developer) of the present invention and the comparative developer 8 (magnetic one-component developer) were manufactured by adding and mixing in a ratio of 2.0% by weight.

<Examples 13 to 15 and Comparative Example 9> Hydrophobic silica fine particles "R-805" (manufactured by Nippon Aerosil Co., Ltd., primary particle size = 12 nm) were added to each of the colored particles B1 to B3 and the colored particle b1. The developers 13 to 15 (non-magnetic one-component developer) of the present invention and the comparative developer 9 (non-magnetic one-component developer) were manufactured by adding and mixing in a ratio of 2.0% by weight.

<Actual Copy Test> (1) Thin Layer Two-Component Developing Method For each of the developers 1 to 2 and the developers 7 to 9 and the comparative developers 1 and 2 and the comparative developer 7 of the present invention, a digital color copying machine was used. "9028" remodeling machine (manufactured by Konica Corporation)
Under high temperature and high humidity environment (33 ℃, relative humidity 80%)
At 20,000 times, live-action tests were conducted and the following items were evaluated.

The developing method in the copying machine is as follows.
The developer adhering to the developing sleeve having a diameter of 20 mm is transferred to a magnetic stainless steel pressure regulating rod (diameter 3 mm, SUS41
No. 6, the pressure regulating force is 10 gf / mm) to form a thin developer layer, and the developer layer develops the electrostatic latent image on the laminated organic photoconductor. . The developing conditions are as follows. Photosensitive member surface potential: -550 V DC bias: -250 V AC bias V _pp: -50~-450V AC Frequency: 1.8 kHz development gap Dsd: thickness of 300μm developer layer (developer 1-2 and Comparative developer 1 ~
2): 150 μm developer layer thickness (Developer 7-9 and comparative developer 7)
: 200 μm

[Evaluation Item] Transition of Toner Adhesion Amount on Photoreceptor (Development Stability) A solid toner image of 20 mm × 50 mm is formed on the photoreceptor at the initial stage of image formation and at the time of 20,000 times of image formation. The image was taken with an adhesive tape before the transfer step and the toner weight per unit area (mg / cm ² ) was measured. Transition of image density (development stability) Stability of image density (development stability) by measuring the image density at the initial stage of image formation and during 20,000 times of image formation
Was evaluated. For the image density measurement, a black solid image was formed, eight arbitrary points of this image were measured with a Macbeth densitometer "Macbeth RD918" to obtain the reflection density, and the average value of the two was used as the image density. Presence or absence of adhesion of toner substance to the surface of the developing sleeve After forming the image 20,000 times, the surface of the developing sleeve was observed by SEM. Presence or absence of toner spent on the carrier After 20,000 times of image formation, the surface of the carrier was observed by SEM. The above results are shown in Table 1 below.

(2) Thin-Layer Magnetic One-Component Developing Method For each of the developers 3 to 4 and the comparative developers 3 to 4 of the present invention, a laser printer “3110” remodeling machine (manufactured by Konica Corporation) was used. Further, the developers 10 to 12 of the present invention
For each of the comparative developer 8 and the comparative developer 8, a laser printer “3015” remodeling machine (manufactured by Konica Corp.) was used and subjected to 20,000 actual shooting tests in a high temperature and high humidity environment (33 ° C., relative humidity 80%). Then, in the same manner as in (1) above, the transition of the amount of toner adhering to the photoconductor (development stability), the transition of image density (development stability), and the presence or absence of adhering toner substances on the surface of the developing sleeve are evaluated. did. Here, in the developing method in each of the laser printers, the developer adhered to the developing sleeve having a diameter of 20 mm is treated by a magnetic pressure stainless steel pressure regulating rod (diameter 3 mm,
A developer layer having a thickness of 100 μm is formed by regulating with a pressure regulation force of 10 gf / mm) made of SUS416, and the electrostatic latent image on the laminated organic photoconductor is developed by this developer layer. The developing conditions are as follows. Photosensitive member surface potential: -550 V DC bias: -250 V AC bias V _pp: -50~-450V AC Frequency: 1.8 kHz development gap Dsd: shows a 200μm above results in the following Table 2.

(3) Thin layer non-magnetic one-component developing method For each of the developers 5 to 6 and the developers 13 to 15 and the comparative developers 5 to 6 and the comparative developer 9 of the present invention, a digital color copying machine "9028" is used. "Remodeling machine (Konica Corporation)
Manufactured under a high temperature and high humidity environment (33 ° C, relative humidity 80
%), The actual test was performed 20,000 times, and as in (1) above, changes in the amount of toner attached to the photoconductor (development stability) and changes in image density (development stability)
Also, the presence or absence of adhesion of the toner substance to the surface of the developing sleeve was evaluated. Here, in the developing method in the copying machine, the urethane blade (pressing force 1
0μg / mm) regulates the thickness to 20μ
m developer layer, and the electrostatic latent image on the photoreceptor is developed by this developer layer. The developing sleeve was in contact with the photoconductor and the developing nip width was about 2 mm. The developing conditions are as follows. Photoconductor surface potential: -550V DC bias (developer 5 to 6 and comparative developer 5 to
6): -250V DC bias (Developers 13 to 15 and Comparative Developer 9): -450V The above results are shown in Table 3 below.

[0084]

[Table 1]

[0085]

[Table 2]

[0086]

[Table 3]

As is clear from the results of Tables 1 to 3, in the actual copying test with the developer of the present invention, the toner adhesion amount to the photoconductor and the image density were stable, and good developability was exhibited for a long period of time. Has been done. Further, no toner substance is attached to the surface of the developing sleeve, and toner spent on the carrier is not generated. In addition, when the surface of the developer of the present invention used for the live-copy test was observed by taking a cross-sectional photograph by a transmission electron microscope (TEM),
No burial of fine silica particles was observed.

On the other hand, in the actual copying test with the comparative developer, the toner adhesion amount to the photoconductor and the image density were significantly decreased with time, and the developing property could not be sufficiently stabilized. Further, adhesion of the toner substance to the surface of the developing sleeve and toner spent on the carrier were generated, and white streaks were observed in the formed image. Further, when the surface of the comparative developer used in the actual copying test was observed in the same manner as above, it was confirmed that silica fine particles were embedded in the surface of the colored particles.

[0089]

EFFECTS OF THE INVENTION Since the developer of the present invention contains irregularly shaped colored particles whose surface is hardened, the surface of the colored particles can also be formed by making the layer thin by the developer layer regulating member. Inorganic particles are hard to be buried in. As a result, the adhesion of the toner substance to the surface of the developing sleeve is effectively prevented, and even when the developer is a two-component developer containing a carrier, the spent is not generated on the carrier and the development accompanied by thin layer formation is performed. In the method, excellent developability can be stably exhibited over a long period of time.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroko Furusawa 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Stock Company

Claims (3)

[Claims] 1. A latent image carrier is provided on a latent image carrier by a developer adhering on a developer carrying carrier, which is made thin by a developer layer regulating member and then carried to a developing region. In the developer used in the developing method for developing the electrostatic latent image, irregular shaped colored particles having a volume average particle diameter of 2.0 to 10.0 μm, and inorganic fine particles having a primary particle diameter of 5 to 100 nm The surface of the irregularly shaped colored particles is hardened. 2. An amorphous colored particle obtained by curing the surface of an amorphous associated particle obtained by associating resin fine particles in the presence of a colorant, by a crosslinking reaction. Item 2. The developer according to Item 1. 3. The developer according to claim 1, wherein the developer contains amorphous colored particles having a cured outer wall formed by an interfacial polymerization method involving a crosslinking reaction.