JP5311288B2 - Carrier, developer using the same, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carrier for electrostatic latent image development which is highly safety for the environment and can be produced inexpensively, and which nonetheless has improved adhesiveness between a coating layer and a core material and is less apt to cause degradation in the image quality accompanying toner spent and film chipping in the coating layer, even when a developer is agitated over a long period of time, and to provide a two-component developer and an image forming method that uses the carrier. <P>SOLUTION: The carrier for a dry two-component developer is a carrier having a core material and a coating layer formed on the surface of the core material and is such that: the coating layer is formed by using a composite resin containing a polysiloxane segment and a segment produced by radical polymerization; and the composite resin is obtained by radical emulsion polymerization of, in the presence of (A) a partial condensate of organosilane, (B) a radical polymerizable monomer and (C) a vinyl crosslinking agent, having a radical polymerizable group and a condensation reactive group that can induce a condensation reaction with the partial condensate of the organosilane. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a carrier for a dry two-component developer used for electrophotography, electrostatic recording, electrostatic printing and the like.

Conventionally, as a method for developing an electrostatic latent image using toner, a cascade development method and a magnetic brush development method are known. In any of these methods, a dry two-component developer is used.
In this dry two-component developer, minute toner particles are held on the surface of relatively large carrier particles by the electric force generated by the friction between both particles. Due to the electric field formed by the electrostatic latent image, the attractive force in the direction of the electrostatic latent image with respect to the toner particles overcomes the binding force between the toner particles and the carrier particles, and the toner particles are attracted and adhered onto the electrostatic latent image. The latent image is visualized. The developer is repeatedly used while replenishing the toner consumed by the development.
In this case, the toner particles must always have the correct chargeability and charge magnitude to be preferentially attracted to the desired image area on the photoconductor. In addition, the carrier must always be triboelectrically charged with a desired polarity and a sufficient charge amount of the toner particles during long-term use.

  However, in conventional developers, a toner film is formed on the carrier surface due to mechanical collision such as collision between developer particles due to multiple sheet copying or collision between developer particles and the developing mechanism, or heat generated by these actions. As a result, so-called spent is generated, the charging characteristics of the carrier are lowered with the use time, and toner scattering, ground fogging, and the like occur, resulting in lower copy quality. And if this spent becomes severe, the entire developer must be replaced.

  Taking these issues into consideration, the toner component on the carrier surface is prevented from being spent, the carrier surface is uniformly formed, surface oxidation is prevented, moisture sensitivity is prevented, the developer life is extended, carrier adhesion to the photoreceptor surface is prevented, For the purpose of protecting the body from scratches or abrasion by the carrier, controlling the charge polarity, or adjusting the charge amount, a coating layer in which the core material surface is coated with a resin material is usually provided.

For example, a carrier in which the core surface is coated with a specific resin material (see Patent Document 1), a carrier in which various additives are added to the coating layer (see Patent Documents 2 to 5), and an additive adhered to the carrier surface. Carriers (see Patent Document 6), carriers in which conductive particles larger than the thickness of the coating layer are contained in the coating layer (see Patent Document 7), and the like have been proposed.
Patent Document 8 proposes using a benzoguanamine-n-butyl alcohol-formaldehyde copolymer as a main component for the coating layer.
Patent Document 9 proposes using a cross-linked product of a melamine resin and an acrylic resin for the coating layer.

However, these proposals still have insufficient durability and suppression of carrier adhesion.
In addition, such a resin-coated carrier is generally obtained by dissolving a coating resin in ketones such as acetone and methyl ethyl ketone, aromatic hydrocarbons such as toluene and xylene, and organic solvents such as dioxane and tetrahydrofuran, and using this solution, For example, it is manufactured by applying to the core material by dipping, spraying, etc. In this case, since these organic solvents have a relatively low boiling point, the danger of explosion and the influence on the human body due to inhalation are large. In addition, a device for recovering the used solvent is necessary, and the cost is high.

In view of the environmental resistance, for example, a carrier coated with an aqueous polyurethane resin composition has been proposed (see Patent Document 10). Certainly, the use of the aqueous resin composition as described above eliminates the danger of explosion and adverse effects on the human body during the production of the carrier, and eliminates the need for solvent recovery, thereby reducing the production cost.
However, when an aqueous polyurethane resin composition is used, its surface energy is high, so that it is inferior in spent resistance as a carrier, and there is a problem in using it for a highly durable developer.

A carrier coated with an aqueous liquid of a silicone-modified acrylic resin has also been proposed (see Patent Document 11). In the carrier using this resin, the acrylic resin part with high adhesion to the core material and the silicone resin part with low surface energy are widely and uniformly present in the coating layer, thus preventing spent and preventing film scraping. Expected to be compatible.
However, in the above document, after forming a coating layer on the surface of the core material, the reaction site capable of condensation reaction is only on the silicone segment when heated and fired, which is sufficient to form a complicated cross-linked structure including the acrylic resin side. is not.
In addition, by adding water-soluble melamine, a stronger coating layer can be formed at the skeleton of the acrylic resin, and further improvement in wear resistance can be expected, but sufficient coating cannot be performed because the viscosity of the coating liquid increases. There was a problem.
In this way, further improvement is necessary to simultaneously realize the wear resistance, spent resistance, and ease of coating of the carrier using the water-based coating layer material in consideration of environmental resistance. Become.

An object of the present invention is to solve the above-described problems and achieve the following objects.
That is, the object of the present invention is to improve the adhesion between the coating layer and the core material while being a resin-coated carrier that is highly safe for the environment and can be manufactured at low cost, and also for a long-term developer stirring. An object of the present invention is to provide a carrier for developing an electrostatic latent image in which deterioration of image quality due to film scraping of spent and coating layers hardly occurs, a two-component developer using the carrier, and an image forming method.

The said subject is solved by following (1)-(7) of this invention.
(1) “A carrier having a core material and a coating layer formed on the surface of the core material, wherein the coating layer is formed using a composite resin including a polysiloxane segment and a segment generated by radical polymerization. In the presence of the (A) organosilane partial condensate, the composite resin is capable of undergoing a condensation reaction with the (B) radical polymerizable monomer and (C) the organosilane partial condensate. A carrier for a dry two-component developer characterized by being obtained by radical emulsion polymerization of a vinyl-based crosslinking agent having a group and a radical polymerization reactive group ",
(2) “The weight mixing ratio of the (A) organosilane partial condensate in the composite resin and the (B) radical polymerizable monomer is 20 to 60:80 to 40”. The electrophotographic carrier according to item (1) ",
(3) "The carrier for electrophotography according to (1) or (2), wherein the carrier coating layer contains fine particles",
(4) “The electrophotographic carrier according to item (3), wherein the fine particles contain at least conductive fine particles”;
(5) "The electrophotographic carrier according to any one of (1) to (4) above, wherein an aminosilane coupling agent is contained in the coating layer",
(6) "Two-component developer comprising the carrier according to any one of (1) to (5) and a toner",
(7) “An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image using the two-component developer according to item (6)” And forming a visible image, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium. Method".

According to the present invention, while being a resin-coated carrier that can solve problems in the past and can be manufactured at low cost with high environmental safety, it can improve the adhesion between the coating layer and the core material, and can be used for a long time. It is possible to provide an electrophotographic carrier that hardly deteriorates in image quality due to film scraping of the toner spent and coating layer even when the developer is stirred, a developer using the carrier, and an image forming method.
It has been recognized that carriers using silicone-based coating resins have excellent toner spent resistance due to their repellency, but have difficulties in mechanical strength such as adhesion to the core material. However, according to the present invention, as will be apparent from the following specific description, in addition to the advantages at the time of production, the adhesion with the core material is improved, and the carrier in which the coating layer is prevented from being scraped, and A two-component developer and an image forming technique using the same are provided.

1 is an example of a process cartridge used in the present invention. 1 is an image forming apparatus according to an embodiment for carrying out the image forming method of the present invention. FIG. 6 is an image forming apparatus according to another embodiment for carrying out the image forming method of the present invention. FIG. FIG. 6 is a tandem image forming apparatus according to another embodiment for carrying out the image forming method of the present invention. FIG. 5 is a partially enlarged schematic view of FIG. 4.

(Career)
The carrier of the present invention has a core material and at least a coating layer on the surface of the core material, and further has other configurations as necessary.
<Core>
The core material is not particularly limited as long as it is magnetic particles, and can be appropriately selected according to the purpose. For example, ferrite, magnetite, iron, and the like are preferable. Among these, ferrite is particularly preferable.
Examples of the ferrite include manganese ferrite, manganese-magnesium ferrite, manganese-strontium ferrite, manganese-magnesium-strontium ferrite, copper-zinc ferrite, and lithium-based ferrite.

Further, for the purpose of controlling the core material resistance and improving the production stability, for example, Li, Na, K, Ca, Ba, Y, Ti, Zr, V, Ag, Ni, Cu, Zn, Al are used for the ferrite. One or more elements such as Sn, Sb and Bi may be blended. As these compounding quantities, 5 atomic% or less of the total amount of metal elements is preferable, and 3 atomic% or less is more preferable.
There is no restriction | limiting in particular in the volume average particle diameter of the said core material, According to the objective, it can select suitably, For example, 10-200 micrometers is preferable and 10-60 micrometers is more preferable.
Here, the volume average particle diameter of the core material can be measured, for example, using a Microtrac particle size analyzer SRA (manufactured by Nikkiso Co., Ltd.) with a range setting of 0.7 to 125 μm.

<Coating layer>
The coating layer contains at least a composite resin, and contains fine particles and, if necessary, other components.
-Composite resin-
As the composite resin, (A) in the presence of an organosilane partial condensate (organosiloxane), (B) a radical polymerizable monomer, (C) a condensation reactive group capable of undergoing a condensation reaction with the organosiloxane, and radical polymerization. It is obtained by radical emulsion polymerization of a vinyl crosslinking agent having a reactive group.
(A) The organosilane condensate is a condensate of an organic silane compound represented by the following formula 1.
R _n SiR ′ _4-n Formula 1
(In the formula, R represents an alkoxy group, R ′ represents an aryl group, an alkyl group, an alkynyl group or an alkenyl group, and part or all of the hydrogen atoms may be substituted with fluorine atoms. And represents an integer of 2 to 4. The carbon number of R is preferably 1 to 6. The carbon number of R ′ is preferably 1 to 6.)
Examples of such organic silane compounds include:
Methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, isobutyltrimethoxysilane, ethyltriethoxysilane, ethyltrimethoxysilane, n-butyltriethoxysilane, n-butyltrimethoxysilane, n -Pentyltrimethoxysilane, n-pentyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-heptyltrimethoxysilane, n-heptyltriethoxysilane and the like.

  The partial condensate of (A) organosilane is a product of partial dehydration condensation reaction between hydroxy groups generated by hydrolysis of alkoxy groups or halogen atoms bonded to Si atoms, and therefore at least at both molecular ends. An erigo- or poly-siloxane in which unreacted hydroxy groups remain. For example, for the purpose of adjusting the hydroxy group value, a polyorganosiloxane having a relatively large average molecular weight and an organic silane compound represented by the above formula 1 can be used in combination. Accordingly, the di-, tri-, or tetra-alkoxy-substituted organosilane of Formula 1 can be said to be a precursor of the (A) organosilane partial condensate.

  (B) As the acrylic monomer used for the radical polymerization reactive polymer, for example, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, heptyl acrylate, dodecyl acrylate, Acrylic acid esters such as 2-hydroxyethyl acrylate, 3-chloro-2-hydroxypropyl acrylate, diethylene glycol monoacrylate, glycerol monoacrylate, N-methylolacrylamide; methyl methacrylate, ethyl methacrylate, methacrylic acid sec-butyl, tert-butyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, 3-chloro methacrylate Methacrylic acid esters such as 2-hydroxypropyl, diethylene glycol monomethacrylic acid ester, glycerin monomethacrylic acid ester, N-methylol methacrylamide; acrylic monomers such as acrylic acid and methacrylic acid, itaconic acid, crotonic acid, fumaric acid , Maleic acid, maleic anhydride and the like. In the case of these components (B), a plurality of types of monomers can be used in combination, for example, a plurality of types of monomers such as butyl acrylate in combination to impart toughness to a high hardness film derived from methyl methacrylate. Can be used in combination.

  Thus, the presence of the polymer portion generated by the radical polymerization reaction in the composite resin strengthens the adhesion between the core material and the fine particles contained in the coating layer, and deteriorates the coating layer such as film scraping or film peeling. Is less likely to occur, and the coating layer can be stably maintained. In particular, it is preferable to hold fine particles having a particle size larger than the coating layer thickness because a powerful effect can be exhibited.

  (C) Vinyl-based crosslinking agent is a compound that enables co-condensation with component (A) and radical emulsion polymerization with component (B). For example, vinyl triethoxysilane, vinyltrimethoxysilane, vinyl tris ( β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltriethoxysilane, vinyldimethylchlorosilane, vinyltrichlorosilane, and other vinyl-based silane coupling agents Can be mentioned.

  In the present invention, the amount ratio [100 × (A) / (A + B)] of the component (A) to the total weight of the components (A) and (B) is preferably 20 to 60 parts. The amount ratio [100 × (B) / (A + B)] of the component (B) to the total weight of the components A) and (B) is preferably 80 to 40 parts. If the amount of the component (A) is less than this, a problem may occur in the toner spent resistance. If the amount of the component (A) is more than this, a problem may occur in the film strength. The amount ratio of the component (C) to the total weight of the components (A) and (B) [100 × (C) / (A + B)] is the type and amount of the component (A), (B) Although depending on the type and amount of the component, it is preferable to use a small amount of 0.1 to 8 parts by weight in order to minimize the reaction opportunity between the molecules of the component (C).

  Surfactants include anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, alkyl Quaternary ammonium salt type cationic surfactants such as trimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol derivative Nonionic surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine can be used.

A radical polymerization initiator is not specifically limited, A conventionally well-known thing can be applied.
For example, persulfates such as potassium persulfate and ammonium persulfate, benzoyl peroxide, lauroyl peroxide, oxochloroperoxybenzoic acid, t-butylperoxy-2-ethylhexaniate, di-t-butyl peroxide, etc. Oxide, 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2 ′ -Azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2 'azobis (2-methylpropionamidine) salt, 2,2'-azobis [N- (2-carboxyethyl) Azo compounds such as 2-methylpropionamidine] and 4,4′-azobis (4-cyanovaleric acid). Among these, water-soluble azo compounds such as 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] and 4,4′-azobis (4-cyanovaleric acid) are preferable.
The radical polymerization initiator may be used as a redox initiator combined with a reducing agent as necessary. By using a redox initiator, the polymerization activity is increased, the polymerization temperature can be lowered, and the polymerization time can be further shortened.

The composite resin can be obtained by emulsifying the component (A), the component (B) and the component (C) in the presence of a surfactant, and adding a polymerization initiator for radical polymerization.
In this polymerization method, since the co-condensation reaction of component (A) and the polymerization reaction of component (B) proceed simultaneously, component (A) and component (B) become a composite resin while forming an interpenetrating structure. Furthermore, by containing (C) vinyl type crosslinking agent, (A) component and (B) component can be connected and a stronger resin can be formed, and the abrasion resistance of a coating layer improves.

-Aminosilane coupling agent-
The coating layer solution may further contain an aminosilane coupling agent for the purpose of controlling the charge amount of the carrier with respect to the toner, and those represented by the following structural formula are preferred.

  The content of the aminosilane coupling agent in the coating layer is preferably 0.001% by mass to 30% by mass, and more preferably 0.001% by mass to 10% by mass. When the content is less than 0.001% by mass, the chargeability is likely to be affected by the environment, and the product yield tends to decrease. When the content exceeds 30% by mass, the coating layer tends to be brittle. In addition, the wear resistance of the coating layer may be reduced.

-Fine particles-
As the material to be contained in the coating layer, fine particles different from the resin component can be further contained, and by selecting an appropriate content and particle diameter with respect to the thickness of the coating layer, the strength of the coating layer can be increased. It can be significantly improved.
As the fine particles, conventionally known materials can be used alone or in combination, and typically include silica fine particles, titanium oxide fine particles, alumina fine particles, and the like. Alumina fine particles are preferably used in order to be charged.
The content of the fine particles in the coating layer is appropriately selected depending on the material constituting the coating layer, but is preferably 1% by mass to 70% by mass, and more preferably 18% by mass to 50% by mass.
When the content is less than 1% by mass, the effect of improving the strength of the coating layer may not be sufficient. When the content exceeds 70% by mass, the particles are likely to be detached from the coating layer. It may cause problems.

Further, in order to make the electric resistance of the carrier appropriate, it is possible to contain a conductive substance in the coating layer. As the conductive substance here, a known conductive material can be used.
Examples of the conductive material, e.g., conductive ZnO, Al or the like metal powders, SnO ₂ doped with SnO ₂ and various elements made by various methods, borides, e.g. _{TiB 2,} ZnB _2, MoB 2 , Silicon carbide and conductive polymers (polyacetylene, polyparaphenylene, poly (para-phenylene sulfide), polypyrrole) and the like.

-Method for forming carrier coating layer-
There is no restriction | limiting in particular as a formation method of the said coating layer, A conventionally well-known method can be used, The method of apply | coating a coating layer solution to the surface of a core material by means, such as a spray method or a dipping method, is mentioned.
Moreover, it is preferable to accelerate the polymerization reaction of the coating layer by applying the coating layer solution to the surface of the core material and heating the carrier on which the coating layer is formed.
The heat treatment may be performed in the coating layer forming apparatus after the coating layer is formed, or may be performed by another heating means such as a normal electric furnace or a firing kiln after the coating layer is formed. Also good.
The heat treatment temperature varies depending on the coating layer material to be used, and is not generally determined, but is preferably 120 ° C to 350 ° C, particularly preferably a temperature equal to or lower than the decomposition temperature of the coating layer, up to about 220 ° C. The upper limit temperature is more preferable, and the heat treatment time is preferably about 5 minutes to 120 minutes.

(Two-component developer)
The two-component developer of the present invention includes the carrier of the present invention and a toner. Thereby, it is possible to obtain an electrophotographic developer capable of suppressing carrier adhesion and corresponding to high image quality.
The mixing ratio of the toner and the carrier in the developer is preferably 2.0 parts by mass to 12.0 parts by mass, and more preferably 2.5 parts by mass to 10 parts by mass with respect to 100 parts by mass of the carrier.

<Toner>
The toner is not particularly limited and can be appropriately selected from those used as electrophotographic toners according to the purpose. The toner includes at least a binder resin and a colorant, and includes a release agent, a charging agent. It contains a control agent and, if necessary, other components.

-Binder resin-
The binder resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, styrene such as polystyrene, poly-p-styrene, polyvinyltoluene, or a homopolymer of a substituted product thereof. Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-methacrylic acid copolymer Polymerization unit, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer Polymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone Copolymer, styrene-butadiene copolymer, styrene-isopropyl copolymer, styrene-copolymer such as styrene-maleic ester copolymer, polythyme methacrylate resin, polybutyl methacrylate resin, polyvinyl chloride resin , Polyvinyl acetate resin, polyethylene resin, polyester resin, polyurethane resin, epoxy resin, polyvinyl butyral resin, polyacrylic acid resin, rosin resin, modified rosin resin, terpene resin, phenol resin, aliphatic or aromatic hydrocarbon resin, aromatic Family petroleum resin and the like. These may be used individually by 1 type and may use 2 or more types together.

-Colorant-
The colorant is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthracene Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Red, Cadmium Red, Cad Muum Mercury Red, Antimon Zhu, Permanent Red 4R, PA Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oh Lured, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Oxidation Chrome, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Ash Examples include degreen lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, and lithopone. These may be used individually by 1 type and may use 2 or more types together.
The content of the colorant in the toner is preferably 1 to 15% by mass, and more preferably 3 to 10% by mass.

The colorant may be used as a master batch combined with a resin.
The resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, styrene or a substituted polymer thereof, styrene copolymer, polymethyl methacrylate resin, polybutyl Methacrylate resin, polyvinyl chloride resin, polyvinyl acetate resin, polyethylene resin, polypropylene resin, polyester resin, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic hydrocarbon resin, alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin and the like. These may be used individually by 1 type and may use 2 or more types together.

-Release agent-
There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably from well-known things, For example, waxes etc. are mentioned suitably.
Examples of the waxes include carbonyl group-containing waxes, polyolefin waxes, and long-chain hydrocarbons. These may be used individually by 1 type and may use 2 or more types together. Among these, a carbonyl group-containing wax is preferable.

Examples of the carbonyl group-containing wax include polyalkanoic acid esters, polyalkanol esters, polyalkanoic acid amides, polyalkylamides, and dialkyl ketones.
Examples of the polyalkanoic acid ester include carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecane. Examples thereof include diol distearate.
Examples of the polyalkanol ester include tristearyl trimellitic acid and distearyl maleate.
Examples of the polyalkanoic acid amide include dibehenyl amide.
Examples of the polyalkylamide include trimellitic acid tristearylamide.
Examples of the dialkyl ketone include distearyl ketone. Of these carbonyl group-containing waxes, polyalkanoic acid esters are particularly preferred.
Examples of the polyolefin wax include polyethylene wax and polypropylene wax.
Examples of the long chain hydrocarbon include paraffin wax and sazol wax.

There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 40-160 degreeC is preferable, 50-120 degreeC is more preferable, 60-90 degreeC is especially preferable.
When the melting point is less than 40 ° C., the wax may adversely affect the heat-resistant storage stability, and when it exceeds 160 ° C., cold offset may easily occur during fixing at a low temperature.
The melt viscosity of the release agent is preferably 5 to 1,000 cps, more preferably 10 to 100 cps, as a measured value at a temperature 20 ° C. higher than the melting point of the wax.
If the melt viscosity is less than 5 cps, the releasability may be lowered, and if it exceeds 1,000 cps, the effect of improving hot offset resistance and low-temperature fixability may not be obtained.
There is no restriction | limiting in particular as content in the said toner of the said mold release agent, Although it can select suitably according to the objective, 1-40 mass% is preferable and 3-30 mass% is more preferable.
When the content exceeds 40% by mass, the fluidity of the toner may be deteriorated.

-Charge control agent-
The charge control agent is not particularly limited, and a positive or negative charge control agent can be appropriately selected and used depending on whether the charge charged on the photoconductor is positive or negative.
As the negative charge control agent, for example, a resin or compound having an electron donating functional group, an azo dye, a metal complex of an organic acid, or the like can be used.
Specifically, Bontron (product numbers: S-31, S-32, S-34, S-36, S-37, S-39, S-40, S-44, E-81, E-82, E -84, E-86, E-88, A, 1-A, 2-A, 3-A) (all manufactured by Orient Chemical Industry Co., Ltd.), Kaya Charge (product numbers: N-1, N-2), Kaya Set Black (product number: T-2, 004) (all manufactured by Nippon Kayaku Co., Ltd.), Eisenspiron Black (T-37, T-77, T-95, TRH, TNS-2) (all Tsuchiya Chemical Industry Co., Ltd.), FCA-1001-N, FCA-1001-NB, FCA-1001-NZ (all manufactured by Fujikura Kasei Co., Ltd.) and the like.

As the positive charge control agent, for example, a basic compound such as a nigrosine dye, a cationic compound such as a quaternary ammonium salt, a metal salt of a higher fatty acid, or the like can be used.
Specifically, Bontron (part numbers: N-01, N-02, N-03, N-04, N-05, N-07, N-09, N-10, N-11, N-13, P -51, P-52, AFP-B) (all manufactured by Orient Chemical Co., Ltd.), TP-302, TP-415, TP-4040 (all manufactured by Hodogaya Chemical Co., Ltd.), copy blue PR, copy Charge (product number: PX-VP-435, NX-VP-434) (both manufactured by Hoechst), FCA (product number: 201, 201-B-1, 201-B-2, 201-B-3, 201) -PB, 201-PZ, 301) (all manufactured by Fujikura Kasei Co., Ltd.), PLZ (product numbers: 1001, 2001, 6001, 7001) (all manufactured by Shikoku Kasei Kogyo Co., Ltd.) and the like.
These may be used individually by 1 type and may use 2 or more types together.

The addition amount of the charge control agent is determined by the toner production method including the type of the binder resin and the dispersion method, and is not uniquely limited. However, with respect to 100 parts by mass of the binder resin. 0.1 mass part-10 mass parts are preferable, and 0.2 mass part-5 mass parts are more preferable.
If the addition amount exceeds 10 parts by mass, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the developer fluidity is reduced, the image If the concentration is less than 0.1 parts by mass, the charge rise property and the charge amount may be insufficient, and the toner image may be easily affected.

As the toner material, in addition to the binder resin, release agent, colorant, and charge control agent, inorganic fine particles, fluidity improver, cleaning improver, magnetic material, metal soap, etc. are added as necessary. can do.
Examples of the inorganic fine particles include silica, titania, alumina, cerium oxide, strontium titanate, calcium carbonate, magnesium carbonate, calcium phosphate, etc., and silica hydrophobized with silicone oil, hexamethyldisilazane, or the like. It is more preferable to use fine particles or titanium oxide subjected to a specific surface treatment.

  Examples of the silica fine particles include, for example, Aerosil (product numbers: 130, 200 V, 200 CF, 300, 300 CF, 380, OX50, TT600, MOX80, MOX170, COK84, RX200, RY200, R972, R974, R976, R805, R811, R812, T805, R202, VT222, RX170, RXC, RA200, RA200H, RA200HS, RM50, RY200, REA200) (all manufactured by Nippon Aerosil Co., Ltd.), HDK (part numbers: H20, H2000, H3004, H2000 / 4, H2050EP, H2015EP, H3050EP, KHD50), HVK2150 (all manufactured by Wacker Chemical Co., Ltd.), Cabozil (Part No .: L-90, LM-130, LM-150, M-5, PTG, MS) 55, H-5, HS-5, EH-5, LM-150D, M-7D, MS-75D, TS-720, TS-610, TS-530) (all manufactured by Cabot Corporation) Can do.

The amount of the inorganic fine particles added is preferably 0.1 parts by mass to 5.0 parts by mass, and more preferably 0.8 parts by mass to 3.2 parts by mass with respect to 100 parts by mass of the toner base particles.
The toner production method is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a pulverization method, a monomer composition containing a specific crystalline polymer and a polymerizable monomer may be used. A polymerization method that directly polymerizes in an aqueous phase (suspension polymerization method, emulsion polymerization method), a composition containing a specific crystalline polymer and an isocyanate group-containing prepolymer directly in the aqueous phase with amines Examples thereof include a polyaddition reaction method using elongation / crosslinking, a polyaddition reaction method using an isocyanate group-containing prepolymer, a method of dissolving in a solvent, removing the solvent and pulverizing, a melt spraying method, and the like.

The pulverization method is, for example, a method of obtaining the toner base particles by melting or kneading the toner material, pulverizing, classifying or the like.
In the case of the pulverization method, for the purpose of increasing the average circularity of the toner, the shape may be controlled by applying a mechanical impact force to the obtained toner base particles. In this case, the mechanical impact force can be applied to the toner base particles using a device such as a hybridizer or mechanofusion.

The above toner materials are mixed, and the mixture is charged into a melt kneader and melt kneaded.
As the melt kneader, for example, a uniaxial continuous kneader, a biaxial continuous kneader, or a batch kneader using a roll mill can be used. For example, KTK type twin screw extruder (manufactured by Kobe Steel Co., Ltd.), TEM type extruder (manufactured by Toshiba Machine Co., Ltd.), twin screw extruder (manufactured by Casey Kay), PCM type twin screw extruder (manufactured by Ikekai Iron Works) , Conyder (manufactured by Busus) and the like are preferably used.
This melt-kneading is preferably performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be broken. Specifically, the melt-kneading temperature is determined with reference to the softening point of the binder resin. If the temperature is higher than the softening point, cutting is severe, and if the temperature is too low, dispersion may not proceed.

In the pulverization, the kneaded product obtained by the kneading is pulverized.
In this pulverization, it is preferable that the kneaded material is first coarsely pulverized and then finely pulverized. At this time, a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing particles by colliding with each other in a jet stream, or pulverizing with a narrow gap between a mechanically rotating rotor and a stator is preferably used.
In the classification, the pulverized product obtained by the pulverization is classified and adjusted to particles having a predetermined particle diameter. The classification can be performed, for example, by removing the fine particle portion by a cyclone, a decanter, centrifugation, or the like.
After the pulverization and classification are completed, the pulverized product is classified into an air stream by centrifugal force or the like to produce a toner having a predetermined particle size.

  The suspension polymerization method is an oil-soluble polymerization initiator, emulsification described later in an aqueous medium in which a colorant, a release agent, and the like are dispersed in a polymerizable monomer and a surfactant and other solid dispersant are contained. Emulsified and dispersed by the method. Thereafter, a polymerization reaction is performed to form particles, and then wet processing for attaching inorganic fine particles to the toner particle surfaces in the present invention may be performed. At that time, it is preferable to treat the toner particles from which excess surfactant and the like are removed by washing.

Examples of the polymerizable monomer include acids such as acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride, acrylamide, By using a part of acrylate, methacrylate, etc. having amino groups such as methacrylamide, diacetone acrylamide or their methylol compounds, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, dimethylaminoethyl methacrylate, etc. Functional groups can be introduced.
Further, by selecting a dispersant having an acid group or a basic group as the dispersant to be used, the dispersant can be adsorbed and left on the particle surface to introduce a functional group.

As the emulsion polymerization method, a water-soluble polymerization initiator and a polymerizable monomer are emulsified in water using a surfactant, and a latex is synthesized by a usual emulsion polymerization method. Separately, a dispersion in which a colorant, a release agent and the like are dispersed in an aqueous medium is prepared, and after mixing, the toner is aggregated to a toner size and heat-fused to obtain a toner. Thereafter, wet processing of inorganic fine particles described later may be performed.
A functional group can be introduced on the surface of the toner particles by using a latex similar to the monomer used in the suspension polymerization method.
Among these, since the selectivity of the resin is high, the low-temperature fixability is high, the granulation property is excellent, and the particle size, particle size distribution, and shape can be easily controlled. And a polymer capable of reacting with the active hydrogen group-containing compound is dissolved or dispersed in an organic solvent to prepare a toner solution, and then the toner solution is emulsified or dispersed in an aqueous medium. In the aqueous medium, the active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound are reacted to form an adhesive substrate in the form of particles, and the organic solvent is What is obtained by removing is suitable.

Examples of the toner material include an adhesive base obtained by reacting an active hydrogen group-containing compound, a polymer capable of reacting with the active hydrogen group-containing compound, a binder resin, a charge control agent, and a colorant. Etc., and further, if necessary, other components such as resin fine particles and a release agent.
Further, in order to improve the fluidity, storage stability, developability and transferability of the toner, inorganic fine particles such as hydrophobic silica fine powder may be further added to and mixed with the toner base particles produced as described above. For mixing the additives, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature.
In order to change the load history applied to the additive, the additive may be added midway or gradually. In this case, you may change the rotation speed, rolling speed, time, temperature, etc. of a mixer. Further, a strong load may be given first, and then a relatively weak load, or vice versa.
Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a Ladige mixer, a Nauter mixer, and a Henschel mixer. Next, the toner is obtained by passing through a sieve of 250 mesh or more to remove coarse particles and aggregated particles.

The shape, size, etc. of the toner are not particularly limited and can be appropriately selected according to the purpose. It is preferable to have a ratio (volume average particle diameter / number average particle diameter) to the average particle diameter.
The average circularity is a value obtained by dividing the perimeter of an equivalent circle having the same projected shape as the toner shape by the perimeter of the actual particles, and is preferably 0.900 to 0.980, for example, 0.950 to 0 .975 is more preferred. Note that particles having an average circularity of less than 0.94 are preferably 15% or less.
If the average circularity is less than 0.900, satisfactory transferability and a high-quality image free from dust may not be obtained, and if it exceeds 0.980, image formation employing blade cleaning or the like is employed. In the system, defective cleaning on the photoconductor and transfer belt occurs, and in the case of image formation with a high image area ratio such as photographic images, an untransferred image is formed due to poor paper feed, etc. The accumulated toner may become a transfer residual toner on the photoconductor, resulting in background smearing of the image, or it may contaminate the charging roller for charging the photoconductor in contact with the original charging ability. It may become impossible to demonstrate.

The average circularity was measured using a flow particle image analyzer FPIA-2100 (manufactured by Sysmex Corporation), and analyzed using analysis software FPIA-2100 Data Processing Program for FPIA version 00-10.
Specifically, 0.1% to 0.5 ml of 10% by weight surfactant [alkylbenzene sulfonate, Neogen SC-A (Daiichi Kogyo Seiyaku Co., Ltd.)] was added to a glass 100 ml beaker, and each toner was added. 0.1g-0.5g was added and it stirred with the microspatel, and 80 ml of ion-exchange water was then added.
The obtained dispersion was subjected to a dispersion treatment for 3 minutes with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.).
The shape and distribution of the toner were measured using the FPIA-2100 until the concentration of the dispersion reached 5,000 to 15,000 / μL. In this measurement method, it is important that the concentration of the dispersion is 5,000 / μL to 15,000 / μL from the viewpoint of measurement reproducibility of the average circularity. In order to obtain the concentration of the dispersion, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant to be added and the amount of toner. Similar to the measurement of the toner particle size described above, the amount of the surfactant varies depending on the hydrophobicity of the toner. If it is added in a large amount, noise due to bubbles is generated, and if it is too small, the toner cannot be sufficiently wetted. It will be enough. Further, the toner addition amount varies depending on the particle size, and it is necessary to decrease the small particle size and to increase the large particle size. When the volume average particle size of the toner is 3 μm to 10 μm, the toner amount is 0.1. By adding ˜0.5 g, the dispersion concentration can be adjusted to 5,000 / μL to 15,000 / μL.

The volume average particle diameter of the toner is not particularly limited and may be appropriately selected depending on the intended purpose. For example, it is preferably 3 μm to 10 μm, and more preferably 3 μm to 8 μm.
When the volume average particle size is less than 3 μm, in the case of a two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be reduced. Therefore, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the variation in the toner particle size may increase.

The ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) in the toner is preferably 1.00 to 1.25, more preferably 1.10 to 1.25.
The volume average particle diameter, and the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) are measured using a particle size analyzer Multisizer III (manufactured by Beckman Coulter, Inc.). Measurement was performed at 100 μm, and analysis was performed with analysis software Beckman Coulter Multisizer 3 Version 3.51.
Specifically, 0.5 ml of 10% by weight surfactant [alkylbenzene sulfonate, Neogen SC-A (Daiichi Kogyo Seiyaku Co., Ltd.)] was added to a 100 ml glass beaker, and 0.5 g of each toner was added. Next, 80 ml of ion-exchanged water was added.
The obtained dispersion was subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser W-113MK-II (manufactured by Honda Electronics Co., Ltd.).
The dispersion was measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter) as a measurement solution.
In the measurement, the toner sample dispersion was dropped so that the concentration indicated by the apparatus was 8 ± 2%.
In this measurement method, it is important that the concentration is 8 ± 2% from the viewpoint of the reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.

Although the charge amount of the toner varies depending on the actual use process, it cannot be determined unconditionally. However, in the combination with the carrier particles according to the configuration of the present invention, the saturation charge amount is 3 μC / g to 40 μC in absolute value. / G is preferable, and 5 μC / g to 30 μC / g is more preferable.
The coloration of the toner is not particularly limited and may be appropriately selected according to the purpose, and may be at least one selected from black toner, cyan toner, magenta toner, and yellow toner. Can be obtained by appropriately selecting the type of the colorant, and is preferably a color toner.

<Container with developer>
The developer-containing container used in the present invention is obtained by accommodating the developer of the present invention in a container.
There is no restriction | limiting in particular as said container, It can select suitably from well-known things, For example, what has a developer container main body and a cap etc. are mentioned suitably.
The size, shape, structure, material and the like of the developer container main body are not particularly limited and can be appropriately selected according to the purpose. For example, the shape is preferably cylindrical. A spiral irregularity is formed on the peripheral surface, and the toner as the contents can be transferred to the discharge port side by rotating, and a part or all of the spiral part has a bellows function, etc. Particularly preferred.
The material of the developer container main body is not particularly limited, and those having good dimensional accuracy are preferable. For example, a resin is preferably used. For example, polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin , Polyacrylic acid, polycarbonate resin, ABS resin, polyacetal resin and the like are preferable.
The developer-containing container of the present invention is easy to store, transport, etc., has excellent handleability, and is suitably used for replenishing the developer by being detachably attached to the process cartridge and image forming apparatus of the present invention described later. can do.

<Process cartridge>
The process cartridge used in the present invention develops an electrostatic latent image carrier carrying an electrostatic latent image and the electrostatic latent image carried on the electrostatic latent image carrier using a developer to make it visible. Development means for forming an image, and other means appropriately selected as necessary.
The developing means includes at least a developer container that contains the developer of the present invention, and a developer carrier that carries and conveys the developer contained in the developer container. Furthermore, a layer thickness regulating member for regulating the thickness of the toner layer to be carried may be provided.
The process cartridge can be detachably mounted on various electrophotographic image forming apparatuses, and is preferably detachably mounted on an image forming apparatus used in the present invention described later.

Here, for example, as shown in FIG. 1, the process cartridge contains an electrostatic latent image carrier (101), and charging means (102), developing means (104), transfer means (108), cleaning means. (107) and other means as required. In FIG. 1, (103) indicates exposure by an exposure means, and (105) indicates a recording medium.
Next, the image forming process by the process cartridge shown in FIG. 1 will be described. The electrostatic latent image carrier (101) is charged by the charging means (102) and rotated by the exposure means (not shown) while rotating in the arrow direction. By exposure (103), an electrostatic latent image corresponding to the exposure image is formed on the surface.
The electrostatic latent image is developed by the developing means (104), and the obtained visible image is transferred to the recording medium (105) by the transfer means (108) and printed out. Next, the surface of the latent electrostatic image bearing member after the image transfer is cleaned by a cleaning unit (107), further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

(Image forming method and image forming apparatus)
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, and a fixing step, and further other steps appropriately selected as necessary, for example, a static elimination step, a cleaning step, and a recycling step. , Including control steps.
The image forming apparatus used in the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit, and further appropriately selected as necessary. The other means, for example, a static elimination means, a cleaning means, a recycling means, a control means, etc. are provided.

The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
The electrostatic latent image carrier (sometimes referred to as “electrophotographic photoreceptor”, “photoreceptor”, “image carrier”) is not particularly limited in terms of material, shape, structure, size, and the like. Although it can be appropriately selected from known ones, the shape is preferably a drum shape, and examples of the material thereof include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors such as polysilane and phthalopolymethine. (OPC) and the like. Among these, amorphous silicon or the like is preferable in terms of long life.

The electrostatic latent image can be formed by, for example, uniformly charging the surface of the electrostatic latent image carrier and then exposing it like an image, and by the electrostatic latent image forming means. Can do.
The electrostatic latent image forming means includes at least a charger that uniformly charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise. .
The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roll, brush, film, rubber blade, etc. Non-contact charger using corona discharge such as a charger, corotron and scorotron.

Further, the charger is preferably one that is arranged in contact or non-contact with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by applying DC and AC voltages in a superimposed manner.
Further, the charger is a charging roller disposed in a non-contact proximity to the electrostatic latent image carrier via a gap tape, and the electrostatic latent image is carried by applying a direct current and an alternating voltage to the charging roller. Those that charge the body surface are preferred.
The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device.
The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger to an image to be formed, and is appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, a back light system in which imagewise exposure is performed from the back surface side of the electrostatic latent image carrier may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image using the developer of the present invention to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the developer of the present invention, and can be performed by the developing unit.
The developing means is not particularly limited as long as it can be developed using the developer of the present invention, and can be appropriately selected from known ones, for example, containing the developer of the present invention, Suitable examples include those having at least a developer capable of bringing the developer into contact or non-contact with the electrostatic latent image, and more preferably a developer equipped with the developer-containing container of the present invention.

The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multicolor developing unit. Well, for example, a developer comprising a stirrer that frictionally stirs and charges the developer and a rotatable magnet roller is preferable.
In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.

The transfer can be performed, for example, by charging the latent electrostatic image bearing member (photosensitive member) with the transfer charger using the visible image, and can be performed by the transfer unit.
The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.
The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. There may be one transfer means or two or more transfer means.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing unit, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable.
Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The fixing device includes a heating body including a heating element, a film in contact with the heating body, and a pressure member in pressure contact with the heating body through the film, and the film and the pressure member It is preferably a unit that heats and fixes a recording medium on which an unfixed image is formed. The heating in the heating and pressing means is usually preferably 80 to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrostatic latent image carrier. Preferably mentioned.

The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier, and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited as long as it can remove the electrophotographic toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Suitable examples include brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

The control step is a step of controlling each of the steps, and can be suitably performed by a control unit.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

One mode for carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG.
An image forming apparatus (100) shown in FIG. 2 includes a photosensitive drum (10) as the electrostatic latent image carrier (hereinafter referred to as “photosensitive member (10)”) and a charging roller (20) as the charging means. An exposure device (30) as the exposure means, a development device (40) as the development means, an intermediate transfer member (50), and a cleaning device (60) as the cleaning means having a cleaning blade, A neutralizing lamp (70) as the neutralizing means.

The intermediate transfer member (50) is an endless belt, and is designed to be movable in the direction of the arrow in the figure by three rollers (51) that are arranged on the inner side and stretch the belt. A part of the three rollers (51) also functions as a transfer bias roller capable of applying a predetermined transfer bias (primary transfer bias) to the intermediate transfer member (50).
An intermediate transfer body cleaning blade (90) is disposed in the vicinity of the intermediate transfer body (50), and a visible image (toner image) is transferred (secondary transfer) to the recording medium (95). A transfer roller (80) serving as the transfer means to which a transfer bias for applying the transfer bias can be applied.
Around the intermediate transfer member (50), there is a corona charger (58) for applying a charge to the visible image on the intermediate transfer member (50) in the rotational direction of the intermediate transfer member (50). An electrostatic latent image carrier (photosensitive drum) (10) and an intermediate transfer member (50) are disposed between the contact portion and the contact portion between the intermediate transfer member (50) and the recording medium (95). Yes.

  The developing device (40) includes a developing belt (41) as a developer carrier, and a black developing unit (45K), a yellow developing unit (45Y), and a magenta developing unit (45M) provided around the developing belt (41). ) And a cyan developing unit (45C). The black developing unit (45K) includes a developer container (42K), a developer supply roller (43K), and a developing roller (44K). The yellow developing unit (45Y) includes a developer container (42Y), a developer supply roller (43Y), and a developing roller (44Y). The magenta developing unit (45M) includes a developer container (42M), a developer supply roller (43M), and a developing roller (44M). The cyan developing unit (45C) includes a developer container (42C), a developer supply roller (43C), and a developing roller (44C). The developing belt (41) is an endless belt, and is rotatably stretched by a plurality of belt rollers, and a part thereof is in contact with the electrostatic latent image carrier (photosensitive drum) (10).

In the image forming apparatus (100) shown in FIG. 2, for example, the charging roller (20) uniformly charges the photosensitive drum (10). An exposure device (30) performs imagewise exposure on the photosensitive drum (10) to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum (10) is developed by supplying toner from the developing device (40) to form a visible image (toner image).
The visible image (toner image) is transferred (primary transfer) onto the intermediate transfer member (50) by the voltage applied from the roller (51), and further transferred onto the transfer paper (95) (secondary transfer). The As a result, a transfer image is formed on the transfer paper (95). The residual toner on the photoconductor (10) is removed by the cleaning device (60), and the charge on the photoconductor (10) is once removed by the charge eliminating lamp (70).

Another mode for carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG.
The image forming apparatus (100) shown in FIG. 3 does not include the developing belt (41) in the image forming apparatus (100) shown in FIG. 3, and a black developing unit (45K), Except that the yellow developing unit (45Y), the magenta developing unit (45M), and the cyan developing unit (45C) are directly opposed to each other, the image forming apparatus (100) shown in FIG. 2 has the same configuration. The same effect is exhibited. In FIG. 3, the same components as those in FIG. 2 are denoted by the same reference numerals.

Another mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG.
The tandem image forming apparatus shown in FIG. 4 is a tandem type color image forming apparatus.
The tandem image forming apparatus includes a copying machine main body (150), a paper feed table (200), a scanner (300), and an automatic document feeder (ADF) (400).
The copying machine main body (150) is provided with an endless belt-like intermediate transfer member (50) at the center. The intermediate transfer member (50) is stretched around the support rollers (14), (15), and (16), and can rotate clockwise in FIG. An intermediate transfer body cleaning device (17) for removing residual toner on the intermediate transfer body (50) is disposed in the vicinity of the support roller (15). The intermediate transfer member (50) stretched between the support roller (14) and the support roller (15) has four image forming units (18) of yellow, cyan, magenta, and black along the conveyance direction. A tandem developing device (120) arranged opposite to each other is arranged. An exposure device (21) is disposed in the vicinity of the tandem developing device (120).

A secondary transfer device (22) is disposed on the side of the intermediate transfer member (50) opposite to the side on which the tandem developing device (120) is disposed. In the secondary transfer device (22), a secondary transfer belt (24), which is an endless belt, is stretched between a pair of rollers (23), and a recording medium (on which the secondary transfer belt (24) is conveyed) The transfer paper) and the intermediate transfer member (50) can contact each other.
A fixing device (25) is disposed in the vicinity of the secondary transfer device (22). The fixing device (25) includes a fixing belt (26) that is an endless belt, and a pressure roller (27) that is pressed against the fixing belt (26).
In the tandem image forming apparatus, in the vicinity of the secondary transfer device (22) and the fixing device (25), a sheet reversing device (28) for reversing the transfer paper for image formation on both sides of the transfer paper. ) Is arranged.

Next, full color image formation (color copying) using the tandem developing device (120) will be described.
That is, first, a document is set on the document table (130) of the automatic document feeder (ADF) (400) or the automatic document feeder (400) is opened and the contact glass (32) of the scanner (300) is opened. A document is set on the document and the automatic document feeder (400) is closed.

  When a start switch (not shown) is pressed, when a document is set on the automatic document feeder (400), the document is transported and moved onto the contact glass (32). ) Immediately after the document is set on the scanner (300), the first traveling body (33) and the second traveling body (34) travel. At this time, light from the light source is irradiated by the first traveling body (33) and reflected light from the document surface is reflected by the mirror in the second traveling body (34), and is read through the imaging lens (35). The color original (color image) is read at (36), and is read as black, yellow, magenta and cyan image information.

  Each image information of black, yellow, magenta, and cyan is stored in each image forming means (18) (black image forming means, yellow image forming means, magenta image forming means, tandem type developing device (120), And cyan image forming means), and each image forming means forms toner images of black, yellow, magenta, and cyan. That is, each image forming means (18) (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem developing device (120) is as shown in FIG. Electrostatic latent image carrier (photosensitive drum) (10) (black electrostatic latent image carrier (10K), yellow electrostatic latent image carrier (10Y), magenta electrostatic latent image carrier, respectively. (10M), a cyan electrostatic latent image carrier (10C), a charging device (160) for uniformly charging the electrostatic latent image carrier (photosensitive drum) (10), and each color image information The electrostatic latent image carrier is exposed (L in FIG. 5) like each color image corresponding image, and an electrostatic latent image corresponding to each color image is formed on the electrostatic latent image carrier. An exposure apparatus to be formed, and the electrostatic latent image for each color toner (black toner) A developing device (61) for developing a toner image using each color toner by developing with a yellow toner, a magenta toner, and a cyan toner, and for transferring the toner image onto the intermediate transfer member (50). A transfer charger (62), a cleaning device (63), and a static eliminator (64) are provided, and each monochrome image (black image, yellow image, magenta image, and Cyan image) can be formed.

  The black image, the yellow image, the magenta image, and the cyan image formed in this way are respectively transferred onto the intermediate transfer member (50) that is rotationally moved by the support rollers (14), (15), and (16). A black image formed on the electrostatic latent image carrier (10K), a yellow image formed on the yellow electrostatic latent image carrier (10Y), and a magenta electrostatic latent image carrier (10M). The formed magenta image and the cyan image formed on the cyan electrostatic latent image carrier (10C) are sequentially transferred (primary transfer). Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member (50) to form a composite color image (color transfer image).

On the other hand, in the paper feed table (200), one of the paper feed rollers (142) is selectively rotated so that the sheet (recording paper) is fed from one of the paper feed cassettes (144) provided in the paper bank (143). ), Separated one by one by the separation roller (145), sent to the paper feed path (146), and conveyed by the conveyance roller (147) to the paper feed path (148) in the copier body (150). Guide and stop against the registration roller (49). Alternatively, the sheet feed roller (142) is rotated to feed out the sheets (recording paper) on the manual feed tray (54), separated one by one by the separation roller (145), and put into the manual feed path (53). Stop against the registration roller (49). The registration roller (49) is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet.
Then, the registration roller (49) is rotated in synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member (50), and the intermediate transfer member (50), the secondary transfer device (22), The sheet (recording paper) is fed between the sheets, and the composite color image (color transfer image) is transferred (secondary transfer) onto the sheet (recording paper) by the secondary transfer device (22). A color image is transferred and formed on (recording paper). The residual toner on the intermediate transfer member (50) after the image transfer is cleaned by the intermediate transfer member cleaning device (17).

  The sheet (recording paper) on which the color image has been transferred is conveyed by the secondary transfer device (22) and sent to the fixing device (25). In the fixing device (25), heat and pressure are applied. The composite color image (color transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw (55) and discharged by the discharge roller (56) and stacked on the discharge tray (57), or switched by the switching claw (55) and the sheet is reversed. The image is reversed by the device (28) and guided again to the transfer position, and an image is recorded also on the back surface. Then, the image is discharged by the discharge roller (56) and stacked on the discharge tray (57).

  The image forming apparatus and the image forming method of the present invention have excellent adhesion between the coating layer and the core material, and even when the developer is stirred for a long time, the image quality is hardly deteriorated due to the toner spent and film removal of the coating layer. Since the two-component developer containing the carrier according to the invention is used, it is possible to provide an image with less toner scattering and scumming over a long period of time.

Examples of the present invention will be described below, but the present invention is not limited to the following examples.
"toner"
(Toner Production Example 1)
-Synthesis of organic fine particle emulsion-
In a reaction vessel in which a stir bar and a thermometer are set, 683 parts by weight of water, sodium salt of ethylene oxide methacrylate adduct sulfate 11 parts by weight of Eleminol RS-30 (manufactured by Sanyo Chemical Industries), 166 parts by weight of methacrylic acid Parts, 110 parts by mass of butyl acrylate, and 1 part by mass of ammonium persulfate were stirred at 3,800 rpm for 30 minutes to obtain a white emulsion.
The system was heated to raise the system temperature to 75 ° C. and reacted for 4 hours.
Further, 30 parts by mass of a 1% by mass ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 6 hours to form a vinyl-based resin (methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt copolymer). An aqueous dispersion [fine particle dispersion 1] was obtained.
The obtained [Fine Particle Dispersion 1] was measured with a particle size distribution analyzer LA-920 (manufactured by Horiba Seisakusho), and the volume average particle size was 110 nm. Further, a portion of the obtained [fine particle dispersion 1] was dried to isolate the resin component. The glass transition temperature (Tg) of the resin was 58 ° C., and the weight average molecular weight was 130,000.

-Preparation of aqueous phase-
990 parts by weight of water, 83 parts by weight of [Fine Particle Dispersion 1], 37 parts by weight of a 48.3% by weight aqueous solution of sodium dodecyldiphenyl ether disulfonate, Eleminol MON-7 (manufactured by Sanyo Chemical Industries), and 90 parts by weight of ethyl acetate The mixture was stirred to obtain a milky white liquid. This is designated as [Aqueous Phase 1].

-Synthesis of low molecular weight polyester-
229 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 529 parts by mass of bisphenol A propylene oxide 3-mole adduct, 208 parts by mass of terephthalic acid, adipic acid 46 parts by mass and 2 parts by mass of dibutyltin oxide were added, reacted at 230 ° C. under normal pressure for 7 hours, further reacted at 5 to 15 mmHg under reduced pressure for 5 hours, and then trimellitic anhydride 44 mass in the reaction vessel. A low molecular weight polyester 1 was obtained by reacting at 180 ° C. for 3 hours under normal pressure.
[Low molecular polyester 1] had a number average molecular weight of 2,300, a weight average molecular weight of 6,700, a glass transition temperature (Tg) of 43 ° C., and an acid value of 25 mgKOH / g.

-Synthesis of intermediate polyester and prepolymer-
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 682 parts by mass of bisphenol A ethylene oxide 2 mol adduct, 81 parts by mass of bisphenol A propylene oxide 2 mol adduct, 283 parts by mass of terephthalic acid, 22 parts by mass of merit acid and 2 parts by mass of dibutyltin oxide were added, reacted at 230 ° C. for 7 hours under normal pressure, and further reacted for 5 hours at a reduced pressure of 10 mmHg to 15 mmHg to obtain [Intermediate Polyester 1].
[Intermediate Polyester 1] had a number average molecular weight of 2,200, a weight average molecular weight of 9,700, a glass transition temperature (Tg) of 54 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 52 mgKOH / g.
Next, 410 parts by mass of [Intermediate Polyester 1], 89 parts by mass of isophorone diisocyanate, and 500 parts by mass of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe. By reacting for a time, [Prepolymer 1] was obtained.
[Prepolymer 1] had a free isocyanate mass% of 1.53%.

-Synthesis of ketimine-
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts by mass of isophoronediamine and 75 parts by mass of methyl ethyl ketone were charged and reacted at 50 ° C. for 4 hours and half to obtain [ketimine compound 1].
The amine value of the obtained [ketimine compound 1] was 417.

-Production of master batch (MB)-
1,200 parts by mass of water, 540 parts by mass of carbon black Printex 35 (manufactured by Dexa) [DBP oil absorption = 42 ml / 100 mg, pH = 9.5] and 1,200 parts by mass of polyester resin were added, and a Henschel mixer (Mitsui Mine) was added. The mixture was kneaded at 110 ° C. for 1 hour using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch 1].

-Preparation of oil phase-
378 parts by mass of [Low molecular polyester 1], 100 parts by mass of carnauba wax, and 947 parts by mass of ethyl acetate are charged in a container in which a stir bar and a thermometer are set, and the temperature is raised to 80 ° C. with stirring. The temperature was kept at 5 ° C. for 5 hours, and then cooled to 30 ° C. in 1 hour. Next, 500 parts by mass of [Masterbatch 1] and 500 parts by mass of ethyl acetate were charged into the container and mixed for 1 hour to obtain [Raw material solution 1].
[Raw material solution 1] 1,324 parts by mass were transferred into a container, and using a bead mill Ultra Visco Mill (manufactured by IMEX), a liquid feed speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads were added. Carbon black and wax were dispersed under the conditions of 80% by volume filling and 3 passes.
Next, 1,324 parts by mass of a 65% by weight ethyl acetate solution of [low molecular weight polyester 1] was added, and the mixture was subjected to two passes with a bead mill under the above conditions to obtain [Pigment / Wax Dispersion 1]. The solid content concentration of [Pigment / Wax Dispersion 1] (130 ° C., 30 minutes) was 50 mass%.

-Emulsification and solvent removal-
[Pigment / Wax Dispersion 1] 749 parts by mass, [Prepolymer 1] 115 parts by mass, and [Ketimine Compound 1] 2.9 parts by mass are placed in a container, and TK homomixer (manufactured by Tokushu Kika Co., Ltd.) is used. After mixing at 5,000 rpm for 2 minutes, 1,200 parts of [Aqueous phase 1] was added to the container and mixed with a TK homomixer at 13,000 rpm for 25 minutes to obtain [Emulsion slurry 1].
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and the solvent was removed at 30 ° C. for 8 hours, followed by aging at 40 ° C. for 24 hours to obtain [Dispersion slurry 1].

-Washing and drying-
[Dispersion Slurry 1] 100 parts by mass were filtered under reduced pressure, and then washed and dried as follows.
(1) 100 parts by mass of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2) 100 parts by mass of a 10% by mass aqueous sodium hydroxide solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure. (3) 100 parts by mass of 10% by mass hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered.
(4) Add 300 parts by mass of ion-exchanged water to the filter cake of (3), mix with a TK homomixer (10 minutes at 12,000 rpm) and then filter twice to obtain [Filter cake 1]. It was.
[Filter cake 1] was dried at 45 ° C. for 48 hours in a circulating dryer. Thereafter, the toner base particles having a volume average particle size of 6.1 μm, a number average particle size of 5.4 μm, and an average circularity of 0.972 were prepared by sieving with a mesh of 75 μm.

-External toner addition-
Next, 100 parts by mass of the obtained toner base particles were mixed with 0.7 part by mass of hydrophobic silica and 0.3 part by mass of hydrophobic titanium oxide using a Henschel mixer to prepare the toner of Production Example 1.

《Career》
(Carrier binder resin production example 1)
<Preparation of binder resin 1 aqueous dispersion>
The homogeneous solution mixed with the following formulation was ice-cooled, emulsified with a high-pressure homogenizer while adding an emulsifier and stirring.
Component (A): Dimethyldimethoxysilane: 20 parts by mass Partial condensate of methyltrimethoxysilane hydrolysis product (Mw = 1400)
(X40-9220 manufactured by Shin-Etsu Chemical Co., Ltd.) ... 27 parts by mass (B) component, methyl methacrylate ... 30 parts by mass, butyl methacrylate ... 30 parts by mass, 2-hydroxyethyl methacrylate ... 2 parts by mass, acrylic acid, 2.8 parts by mass (C) component, γ-methacryloxytrimethoxysilane, 1.4 parts by mass emulsifier, sodium dodecylbenzenesulfonate, 1 part by mass Was placed in a separable flask and purged with nitrogen while stirring. Then, potassium persulfate (0.7 parts by mass) as a polymerization initiator was added, and a polymerization reaction was carried out at 65 ° C. for 4 hours.
The following materials were added as curing accelerators to the aqueous dispersion 1 obtained after polymerization to obtain a binder resin 1 aqueous dispersion.
Curing accelerator / oxazoline-based aqueous emulsion K2020 (manufactured by Nippon Shokubai Co., Ltd.) ... 5 parts by mass-Dibutyltin dilaurate 2% aqueous dispersion--2 parts by mass

(Carrier binder resin production example 2)
<Preparation of binder resin 2 aqueous dispersion>
The homogeneous solution mixed with the following formulation was ice-cooled, emulsified with a high-pressure homogenizer while adding an emulsifier and stirring.

Component (A): Dimethyldimethoxysilane: 8 parts by mass: X40-9220 (manufactured by Shin-Etsu Chemical Co., Ltd.): 67 parts by mass (B) Component: Methyl methacrylate: 22 parts by mass: Butyl methacrylate 22 parts by mass 2-hydroxyethyl methacrylate 2 parts by mass Acrylic acid 3 parts by mass (C) component γ-methacryloxytrimethoxysilane 1 part by weight emulsifier sodium dodecylbenzenesulfonate ... 1 part by mass This product was put into a separable flask, and after stirring and replacing with nitrogen, potassium persulfate (0.7 parts by mass) as a polymerization initiator was added, and the mixture was stirred at 65 ° C for 4 hours. A polymerization reaction was performed.
The following materials were added as curing accelerators to the aqueous dispersion 2 obtained after the polymerization to obtain a binder resin 2 aqueous dispersion.
Curing accelerator / oxazoline-based aqueous emulsion K2020 (manufactured by Nippon Shokubai Co., Ltd.) ... 5 parts by mass-Dibutyltin dilaurate 2% aqueous dispersion--2 parts by mass

(Carrier binder resin production example 3)
<Preparation of binder resin 3 aqueous dispersion>
The homogeneous solution mixed with the following formulation was ice-cooled, emulsified with a high-pressure homogenizer while adding an emulsifier and stirring.
Component (A): Dimethyldimethoxysilane: 8 parts by mass: X40-9220 (manufactured by Shin-Etsu Chemical Co., Ltd.): 8 parts by mass (B) Component: Methyl methacrylate: 47 parts by mass: Butyl methacrylate · 47 parts by mass · 2-hydroxyethyl methacrylate · · 4 parts by mass · Acrylic acid · · · 4 parts by mass (C) component · γ-methacryloxytrimethoxysilane ... 1 part by mass emulsifier · Sodium dodecylbenzenesulfonate ... 1 part by mass This product was put into a separable flask, and after stirring and replacing with nitrogen, potassium persulfate (0.7 parts by mass) as a polymerization initiator was added, and the mixture was stirred at 65 ° C for 4 hours. A polymerization reaction was performed.
The following materials were added as curing accelerators to the aqueous dispersion 3 obtained after polymerization to obtain a binder resin 3 aqueous dispersion.
Curing accelerator / oxazoline-based aqueous emulsion K2020 (manufactured by Nippon Shokubai Co., Ltd.) ... 5 parts by mass-Dibutyltin dilaurate 2% aqueous dispersion--2 parts by mass

(Carrier binder resin production example 4)
<Preparation of binder resin 4 aqueous liquid>
2-Propanol (150 parts by mass) was charged into a 500 ml flask equipped with a stirrer, thermometer, condenser, nitrogen gas inlet tube, and dropping device, and heated to 80 ° C. in a nitrogen atmosphere. Next, a monomer solution in which the following materials were dissolved was continuously dropped into the reaction vessel over 2 hours, aged for 4 hours, and then cooled to room temperature.
Silicone macromonomer: 50 parts by mass However, the silicone macromonomer has the following structure.
R1 = R2 = methyl group, n = about 120

・メチルメタクリレート ・・・３０質量部
・２−ヒドロキシエチルメタクリレート ・・・２０質量部
・２，２’−アゾビスイソブチロニトリル ・・・０．５質量部
次に、トリエチルアミン水溶液でｐＨ７に調整した後再度加熱し、２−プロパノールを系外に除去し合成樹脂を得た。そこに水溶性メラミン樹脂 サイメル３５０（三井サイアナミッド社製）（２質量部）及び水を添加し、結着樹脂４水性液とした。

· Methyl methacrylate ··· 30 parts by mass · 2-hydroxyethyl methacrylate · · · 20 parts by mass · 2,2'-azobisisobutyronitrile ··· 0.5 parts by mass Then, the mixture was heated again to remove 2-propanol out of the system to obtain a synthetic resin. Water-soluble melamine resin Cymel 350 (manufactured by Mitsui Cyanamid Co., Ltd.) (2 parts by mass) and water were added thereto to obtain a binder resin 4 aqueous solution.

<Preparation of carrier 1>
The following formulation was dispersed with a homomixer for 10 minutes to prepare a coating layer solution.
-Binder resin 1 water dispersion (solid content 41% by mass) ... 200 parts by mass-Alumina fine particles (Sumitomo Chemical Co., Ltd. Sumirakondam AA-04 particle size 0.4 µm) ... 40 parts by mass-Aminosilane cup Ring agent (manufactured by Dow Corning Toray, SH6020, solid content 100% by mass) ... 3.8 parts by mass Next, ferrite powder (saturated magnetic moment 65 emu / g at 1 k gauss) is used as a core material, [Coating layer solution 1] was applied on the surface of the core material so as to have a thickness of 0.2 μm using a rolling fluid coating apparatus and dried.
The obtained carrier was allowed to stand in an electric furnace at 140 ° C. for 60 minutes and fired. After cooling, the ferrite powder bulk was pulverized using a sieve having an opening of 90 μm to obtain carrier 1.
When the particle size distribution of the obtained carrier 1 was measured with a Microtrac particle size distribution model Model HR9320-X100 (manufactured by Nikkiso Co., Ltd.), the weight average particle size (Dw) was 39.8 μm, and the number average particle size (Dn) was 33. .3 μm and Dw / D was 1.20.

<Production of Carrier 2>
The following formulation was dispersed with a homomixer for 10 minutes to prepare a coating layer solution, which was coated in the same manner as in Example 1 to produce Carrier 2.
-Binder resin 1 aqueous dispersion (solid content 41% by mass) ... 190 parts by mass-Alumina fine particles (Sumitomo Chemical Co., Ltd. Sumirakondam AA-04 particle size 0.4 µm) ... 40 parts by mass-Aminosilane cup Ring agent (Toray Dow Corning Co., Ltd., SH6020, solid content: 100% by mass) 15 parts by mass The particle size distribution of the obtained carrier 2 is measured with a Microtrac particle size distribution model Model HR9320-X100 (manufactured by Nikkiso Co., Ltd.) When measured, the weight average particle diameter (Dw) was 39.5 μm, the number average particle diameter (Dn) was 33.2 μm, and Dw / D was 1.19.

<Preparation of carrier 3>
The following formulation was dispersed with a homomixer for 10 minutes to prepare a coating layer solution, which was coated in the same manner as in Example 1 to produce carrier 3.
-Binder resin 1 aqueous dispersion (solid content 41% by mass) ... 150 parts by mass-Alumina fine particles (Sumitomo Chemical Co., Ltd. Sumirakondam AA-04 particle size 0.4 µm) ... 70 parts by mass-Aminosilane cup Ring agent (Toray Dow Corning Co., Ltd., SH6020, solid content: 100% by mass) ... 6.6 parts by mass The particle size distribution of the obtained carrier 3 was measured using a Microtrac particle size distribution model Model HR9320-X100 (manufactured by Nikkiso Co., Ltd.) ), The weight average particle diameter (Dw) was 39.1 μm, the number average particle diameter (Dn) was 33.1 μm, and Dw / D was 1.18.

<Preparation of carrier 4>
The following formulation was dispersed with a homomixer for 10 minutes to prepare a coating layer solution, which was coated in the same manner as in Example 1 to produce carrier 4.
-Binder resin 2 aqueous dispersion (solid content 43% by mass) ... 200 parts by mass-Alumina fine particles (Sumitomo Chemical Co., Ltd. Sumirakondam AA-04 particle size 0.4 µm) ... 40 parts by mass-Aminosilane cup Ring agent (Toray Dow Corning Co., Ltd., SH6020, solid content: 100% by mass) ... 3.8 parts by mass The particle size distribution of the obtained carrier 4 was measured using a Microtrac particle size distribution model Model HR9320-X100 (manufactured by Nikkiso Co., Ltd.) ), The weight average particle diameter (Dw) was 38.8 μm, the number average particle diameter (Dn) was 33.6 μm, and Dw / D was 1.15.

<Preparation of carrier 5>
The following formulation was dispersed with a homomixer for 10 minutes to prepare a coating layer solution, which was coated in the same manner as in Example 1 to produce carrier 5.
-Binder resin 3 aqueous dispersion (solid content 44% by mass) ... 200 parts by mass-Alumina fine particles (Sumitomo Chemical Co., Ltd. Sumirakondam AA-04 particle size 0.4 µm) ... 40 parts by mass-Aminosilane cup Ring agent (Toray Dow Corning Co., Ltd., SH6020, solid content: 100% by mass) ... 3.8 parts by mass The particle size distribution of the obtained carrier 5 was measured using a Microtrac particle size distribution model Model HR9320-X100 (Nikkiso Co., Ltd. ), The weight average particle diameter (Dw) was 38.8 μm, the number average particle diameter (Dn) was 34.1 μm, and Dw / D was 1.20.

(Comparative Example 1)
<Preparation of carrier 6>
The carrier 6 was produced by adding pure water (100 parts by mass) to the binder resin 4 aqueous liquid (100 parts by mass) to prepare a coating solution, and coating was performed in the same manner as in Example 1.
When the particle size distribution of the obtained carrier 6 was measured with a Microtrac particle size distribution meter (Model HR9320-X100, manufactured by Nikkiso Co., Ltd.), the weight average particle size (Dw) was 39.2 μm, and the number average particle size (Dn) was It was 34.1 μm and Dw / D was 1.15.

(Comparative Example 2)
<Preparation of carrier 7>
Binder 4 was prepared by adding pure water (100 parts by mass) to an aqueous liquid (100 parts by mass) to prepare a coating solution, and coating was performed in the same manner as in Example 2 to prepare carrier 7.
When the particle size distribution of the obtained carrier 7 was measured with a Microtrac particle size distribution analyzer (model HR9320-X100, manufactured by Nikkiso Co., Ltd.), the weight average particle size (Dw) was 39.2 μm, and the number average particle size (Dn) was 34.6 μm and Dw / D was 1.17.

-Production of developer-
The produced [Toner 1] and [Carriers 1 to 7] were adjusted at a ratio such that the carrier coverage with the toner was 50%, and stirred with a tumbler mixer (manufactured by Shinmaru Enterprises Co., Ltd.). And the developer of Comparative Examples 1-2 was produced.
Using each developer thus obtained, peeling and scraping of the coating layer, toner spent property, image density, toner scattering property, and background stain were evaluated as follows. The results are shown in Table 1.

<Evaluation of peeling and shaving of coating layer>
Each developed developer was evaluated for 200,000 sheets using a tandem color image forming apparatus imagio Neo450 (manufactured by Ricoh Co., Ltd.). did.
〔Evaluation criteria〕
A: Ratio of resistance after 200,000 sheets run / initial resistance within 1 to 1/10 ○: Ratio of resistance after 200,000 sheets run / initial resistance of run within 1/10 to 1/100 Δ: Resistance ratio after 200,000 sheets run / initial resistance of run is within 1/100 to 1/1000 ×: Resistance ratio after 200,000 sheets run / initial resistance is less than 1/1000 The amount of resistance reduction in the term "Initial carrier is put between resistance measuring parallel electrodes: gap 2mm electrode, DC200V is applied and the resistance value after 30 sec is a high resist meter High Resistance Meter (manufactured by Yokogawa Hewlett-Packard Co., Ltd.) From the value (R1) obtained by converting the value measured in step 1 into the volume resistivity, the carrier in which the toner in the developer after running was removed by the blow-off device was measured by the same method as the resistance measurement method. Good value to the amount obtained by subtracting the (R2), the target value is 2.0 [Log (Ω · cm)] below.
Moreover, since the cause of resistance reduction is detachment | desorption from the core material of the coating layer of a carrier, the amount of resistance reduction can be suppressed by reducing scraping.

<Evaluation of toner spent property>
Using the developed developer tandem type color image forming apparatus imagio Neo450 (manufactured by Ricoh Co., Ltd.), the toner density is controlled so that the image density of the 20% image area becomes 1.4 ± 0.2. However, the change in the charge amount (μc / g) of the developer after output of 200,000 sheets was evaluated according to the following criteria in comparison with the initial agent before output. The charge amount was measured by a blow-off method.
〔Evaluation criteria〕
◎: Ratio of charge amount after 200,000 sheets run / initial charge amount within 0-15% ○: Ratio of charge amount after 200,000 sheets run / initial charge amount within 15-30% △: Ratio of charge amount after 200,000 sheet run / initial charge amount within 30 to 50% ×: Ratio of charge amount after 200,000 sheet run / initial charge amount is greater than 50% Toner spent on carrier As a result, the composition of the outermost surface of the carrier changes and the charge amount decreases. It is determined that the smaller the ratio of the charge amount before and after the run, the less the toner spent on the carrier.

<Evaluation of image density>
Next, each developer obtained is attached to a copy paper (TYPE6000 <70W>, manufactured by Ricoh Co., Ltd.) using a tandem color image forming apparatus imagio Neo 450 (manufactured by Ricoh Co., Ltd.). A solid image of 1.00 ± 0.05 mg / cm ² was formed. The solid image was repeatedly formed on 200,000 copy sheets.
The image density of the obtained solid image was observed visually at the initial stage and after endurance of 200,000 sheets, and evaluated based on the following criteria. Note that the higher the image density obtained, the higher the density image can be formed. This evaluation corresponds to an example of the developer and the image forming method of the present invention.
〔Evaluation criteria〕
A: The image density did not change at the initial stage and after endurance of 200,000 sheets, and high image quality was obtained. O: After endurance of 200,000 sheets, the image density was slightly decreased, but high image quality was obtained. Δ: 20 Image density decreased and image quality deteriorated after endurance of 10,000 sheets. ×: Image density significantly decreased and image quality significantly decreased after endurance of 200,000 sheets.

<Evaluation of toner scattering property>
The degree of toner contamination in the machine when a chart with an image area ratio of 5% is output continuously by using a tandem color image forming apparatus imagio Neo 450 (manufactured by Ricoh Co., Ltd.) according to the following criteria is 4 Rated by stage.
〔Evaluation criteria〕
A: There is no toner contamination in the image forming apparatus and it is in a good state. ○: There is no toner contamination in the image forming apparatus and it is in a good state. Δ: There is toner contamination in the image forming apparatus, but it is actually used. Possible level ×: Toner contamination in the image forming apparatus is severe and is not practically usable.

<Evaluation of dirt>
The degree of background stain on the background of the image when the 200% continuous image chart with an image area ratio of 5% is output continuously using the tandem color image forming apparatus imagio Neo 450 (manufactured by Ricoh Co., Ltd.) is visually observed according to the following criteria. evaluated.
〔Evaluation criteria〕
○: No background stain on the image background △: Some background stain on the image background ×: Background stain on the image background

<Comprehensive evaluation>
From the above evaluation results, the following criteria were used for overall evaluation.
〔Evaluation criteria〕
◎: Very good ○: Good △: Bad ×: Extremely bad

表１から、本発明のキャリアは製造性において優れており、また本発明のキャリアを含有する現像剤は充分安定した帯電性を示し且つ耐久性においても優れていることが分かる。

From Table 1, it can be seen that the carrier of the present invention is excellent in manufacturability, and the developer containing the carrier of the present invention exhibits sufficiently stable charging properties and is excellent in durability.

(About Figure 1)
DESCRIPTION OF SYMBOLS 101 Electrostatic latent image carrier 102 Charging means 103 Exposure by exposure means 104 Development means 105 Recording medium 107 Cleaning means 108 Transfer means

(About Figures 2 and 3)
DESCRIPTION OF SYMBOLS 10 Photosensitive drum 20 Charging roller 30 Exposure apparatus 40 Developing apparatus 41 Developing belt 42K Developer accommodating part 42Y Developer accommodating part 42M Developer accommodating part 42C Developer accommodating part 43K Developer supply roller 43Y Developer supply roller 43M Developer supply Roller 43C Developer supply roller 44K Development roller 44Y Development roller 44M Development roller 44C Development roller 45K Black development unit 45Y Yellow development unit 45M Magenta development unit 45C Cyan development unit 50 Intermediate transfer member 51 Roller 58 Corona charger 60 Cleaning device 70 Static discharge lamp 80 Transfer roller 90 Intermediate transfer member cleaning blade 95 Recording medium 100 Image forming apparatus

(About FIGS. 4 and 5)
10K Black electrostatic latent image carrier 10Y Yellow electrostatic latent image carrier 10M Zenta electrostatic latent image carrier 10C Cyan electrostatic latent image carrier 10 Electrostatic latent image carrier 14 Support roller 15 Support roller 16 Support roller 17 Intermediate transfer member cleaning device 18 Image forming means 21 Exposure device 22 Secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet reversing device 32 Contact glass 33 First traveling body 34 Second traveling member 35 Imaging lens 36 Reading sensor 49 Registration roller 50 Intermediate transfer member 52 Separating roller 53 Manual feed path 54 Manual feed tray 55 Switching claw 56 Discharge roller 57 Discharge tray 61 Developing device 62 Transfer charger 63 Cleaning device 64 Static eliminator 120 Tandem developer 130 Document base 142 Paper feed roller 14 Paper bank 144 sheet cassette 145 separating roller 146 feed path 147 transport rollers 148 feed path 150 copying apparatus main body 160 a charging device 200 feeder table 300 Scanner 400 automatic document feeder (ADF)
L exposure

JP 58-108548 A JP 54-1555048 A JP 57-40267 A JP 58-108549 A JP 59-166968 A Japanese Patent No. 3120460 JP-A-9-160304 JP-A-8-6307 Japanese Patent No. 2683624 JP-A-5-127431 JP 2006-178508 A

Claims (7)

  A carrier having a core material and a coating layer formed on the surface of the core material, wherein the coating layer is formed using a composite resin containing a polysiloxane segment and a segment generated by radical polymerization; In the presence of (A) a partial condensate of organosilane, the composite resin comprises (B) a radical polymerizable monomer, (C) a condensation reactive group capable of performing a condensation reaction with the partial condensate of organosilane, and radical polymerization. A carrier for a dry two-component developer, which is obtained by radical emulsion polymerization of a vinyl crosslinking agent having a reactive group.   2. The weight mixing ratio of the (A) organosilane partial condensate in the composite resin and the (B) radical polymerizable monomer is 20 to 60:80 to 40, according to claim 1. Electrophotographic carrier.   3. The electrophotographic carrier according to claim 1, wherein the carrier coating layer contains fine particles.   The electrophotographic carrier according to claim 3, wherein the fine particles contain at least conductive fine particles.   The electrophotographic carrier according to claim 1, wherein the coating layer contains an aminosilane coupling agent.   6. A two-component developer comprising the carrier according to claim 1 and a toner.   An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image using the two-component developer according to claim 6 to form a visible image An image forming method comprising: a developing step for transferring, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium.

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