JP2002258531A - Electrophotographic toner and image forming method - Google Patents

Abstract

[PROBLEMS] An electronic device for a one-component developer that prevents a developing sleeve and a layer thickness regulating member (blade or roller) from being contaminated by fusion and also prevents photoconductor filming even in long-term use. Provide photographic toner. SOLUTION: In the electrophotographic toner for a one-component developer, as a binder resin, there is no THF insoluble matter, and the content ratio of a component having a molecular weight of 500 or less in a molecular weight distribution by gel permeation chromatography is 4% by weight or less. Yes, use a polyester resin having one peak in the molecular weight region of 3,000 to 9000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a toner used as a developer for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like, and an electrophotographic developing apparatus using the toner. About. More specifically, an external additive for electrophotographic toner, an electrophotographic toner, an electrophotographic developer, and an electrophotographic developer used for a copier, a laser printer, and a plain paper fax machine using a direct or indirect electrophotographic developing method. Related to the device. Further, the present invention relates to an electrophotographic toner, an electrophotographic developer, and an electrophotographic developing device used for a full-color copying machine, a full-color laser printer, a full-color plain paper facsimile, etc. using a direct or indirect electrophotographic multicolor image developing system.

[0002]

2. Description of the Related Art A developer used in electrophotography, electrostatic recording, electrostatic printing, and the like is, for example, once applied to an image carrier such as a photosensitive member on which an electrostatic image is formed in a developing process. After being adhered and then transferred from the photoreceptor to a transfer medium such as transfer paper in a transfer step, it is fixed on the paper surface in a fixing step. At this time, as a developer for developing an electrostatic image formed on the latent image holding surface, a two-component developer composed of a carrier and a toner and a one-component developer (a magnetic toner, Non-magnetic toner) is known. In the two-component developing method, the developer deteriorates due to the toner particles adhering to the carrier surface, and the toner concentration in the developer decreases because only the toner is consumed.
The mixing ratio with the carrier must be maintained at a constant ratio, which causes a disadvantage that the developing device becomes large. On the other hand, the one-component developing method does not have the above-mentioned drawbacks and has advantages such as downsizing of the apparatus, so that the developing method is becoming mainstream.

In recent years, office automation and colorization in offices have been further advanced, and not only copying of conventional manuscripts consisting only of characters, but also manuscripts including graphs and the like created by a personal computer are output by a printer and used for presentation. Opportunities to copy a large number of documents as materials are increasing. Many of printer output images are solid images, line images, and halftone images, and accordingly, the market demand for image quality is changing, and demands for high reliability and the like are further increasing.

Heretofore, an electrophotographic process using a one-component developer has a magnetic one-component developing method using a magnetic toner,
It is classified into a non-magnetic one-component developing method using a non-magnetic toner. The magnetic one-component developing method uses a developer carrier provided with a magnetic field generating means such as a magnet inside, holds a magnetic toner containing a magnetic substance such as magnetite, and develops a thin layer by a layer thickness regulating member. In recent years, a large number of printers have been put to practical use. On the contrary,
In the non-magnetic one-component developing method, since the toner does not have a magnetic force, a toner supply roller or the like is pressed against the developer carrier to supply the toner onto the developer carrier and electrostatically hold the toner. And develop the film. It has the advantage of being able to cope with colorization because it does not contain a colored magnetic material.Because it does not use a magnet for the developer carrier, it is possible to reduce the weight and cost, and in recent years it has been put to practical use in small full-color printers etc. I'm starting. However, at present, there are still many problems to be improved in the one-component developing system.

In the two-component developing system, a carrier is used as a means for charging and transporting the toner. The toner and the carrier are sufficiently stirred and mixed in the developing device, and then transported to the developer carrier to be developed. It is possible to maintain stable charging and conveyance even when used for a long time, and it is easy to cope with a high-speed developing device.

On the other hand, in the one-component developing system, since there is no stable charging and transporting means such as a carrier, charging and transporting defects due to long-time use and high speed are likely to occur. That is, in the one-component developing method, after the toner is conveyed onto the developer carrying member, the toner is thinned and developed by the layer thickness regulating member, but the toner and the developer carrying member, the layer thickness regulating member and the like are charged by friction. Since the contact and frictional charging time with the member is very short, the amount of low-charge and reverse-charge toner tends to increase more than in the two-component developing method using a carrier.

In particular, in a non-magnetic one-component developing method, toner (developer) is usually conveyed by at least one toner conveying member, and an electrostatic latent image formed on a latent image carrier is conveyed by the conveyed toner. Although a developing unit is employed, the thickness of the toner layer on the surface of the toner conveying member must be reduced as much as possible. This is that also the case to use a carrier are very small diameter or a two-component developer, also use a higher electric resistance as a toner used, in particular a one-component developer In such a case, it is necessary to charge the toner by a developing device, so that the layer thickness of the toner must be significantly reduced. This is because if the toner layer is thick, only the vicinity of the surface of the toner layer is charged, and it is difficult to uniformly charge the entire toner layer. For this reason, the toner is required to maintain a more rapid charging speed and an appropriate charging amount.

As for the binder resin, in order to impart sharp meltability and fixability to the binder resin for a full-color toner, a method of reducing the molecular weight and softening temperature of the resin has been adopted. Since the resin strength of the binder resin is impaired, there has been a problem that when the linear velocity is increased, fusion to the surface of the sleeve occurs, whereby the durability decreases and filming easily occurs. In order to prevent such toner from being fused and filmed to a sleeve or a blade, a method of introducing a crosslinking agent into a binder resin or increasing the glass transition temperature of the resin has been adopted. However, sufficient strength cannot be imparted even to such a binder resin, and the fusion of the toner to the sleeve or the blade and the occurrence of filming cannot be sufficiently solved.

[0009]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a resin charge control agent having excellent compatibility with a binder resin, excellent transparency of a toner-fixed image, and excellent stability. The purpose is to solve the problem.

That is, the object of the present invention is as follows. (1) Even when used for tens of thousands of sheets or more, an electrophotographic toner, developer, and the like, which prevent the developing sleeve and the layer thickness regulating member (blade or roller) from being contaminated by fusion and prevent photoreceptor filming. To provide an image forming method. (2) To provide an electrophotographic toner, a developer, and an image forming method with less toner scattering in a developing machine even during long-term use. (3) Toners for electrophotography which make it possible to use the developing unit and the photoreceptor unit for a long period of time, thereby reducing the burden on the environment and reducing the time and effort for replacing the user.
To provide a developer and an image forming method. (4) Sharp melt properties and color developability as full color,
Provided is an electrophotographic toner which has excellent filming properties without fusing to a sleeve and a blade without impairing fixability and blocking resistance. (5) In a toner production process including a process of kneading, pulverizing, and classifying a toner, there is no sticking in the pulverization process, and a high productivity electrophotographic toner that is not excessively pulverized and has a large pulverization amount per unit time. To provide.

[0011]

Means for Solving the Problems The inventors of the present invention focused on a binder resin, which is a component of an electrophotographic toner for a one-component developer, in order to solve such a problem, and as a result, a specific The inventors have found that the object can be achieved by using a polyester resin, and have reached the present invention. That is, the specific polyester resin is T
There is no HF insoluble matter, and the content of components having a molecular weight of 500 or less in the molecular weight distribution by gel permeation chromatography is 4% by weight or less, and the molecular weight is 3000 or less.
It has one peak in the region of ９9000.

The present invention has been made based on the above findings, and has the following aspects. (1) An electrophotographic toner for a one-component developer comprising at least a polyester resin as a binder resin and a colorant, wherein the polyester resin has no THF-insoluble components,
In the molecular weight distribution in the gel permeation chromatography, the content of the component having a molecular weight of 500 or less was 4%.
A toner for electrophotography, which is a polyester resin having a weight percent or less and one peak in a molecular weight region of 3,000 to 9000. (2) The electrophotographic toner as described in (1) above, wherein the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of the polyester resin is 2 to 10. (3) A one-component developing method using the electrophotographic toner according to the above (1) or (2), comprising a conveying member, a toner layer thickness regulating member, and a toner replenishment auxiliary member;
Using a developing device in which the toner layer thickness regulating member and the toner conveying member are in contact with each other, the toner thinned on the toner conveying member is supplied to the surface of the electrostatic latent image carrier to develop the latent image. A one-component developing method. (4) Set the toner conveying member to 160 mm / sec or more, 28
The one-component developing method according to the above (3), wherein the rotation is performed at 0 mm / sec or less. (5) a latent image forming step of forming a latent image on the latent image holding member, a developing step of developing the latent image using a developer on a developer carrier, and transferring the developed toner image onto a transfer member And a fixing step of heating and fixing the toner image on the transfer body, wherein the toner for electrophotography according to (1) or (2) is used as the toner for one-component developer. Image forming method. (6) The image forming method according to the above (5), wherein the developing step comprises forming a thin layer of the developer on the developer carrying member and developing it with or without contacting the latent image holding member. (7) Divided into multiple colors formed on the electrostatic image carrier by a plurality of multicolor developing devices including a developing roll and a regulating member for uniformly regulating the layer thickness of the developer supplied on the developing roll. The developed electrostatic latent image is developed on a plurality of electrostatic image carriers corresponding to each color by a developer corresponding to each color, and a transfer unit is provided on the surface of the electrostatic image carrier via a transfer material. An electrophotographic developing method using an electrophotographic recording device that electrostatically transfers the toner image onto the transfer material in contact with the electrophotographic image forming apparatus, wherein the toner according to (1) or (2) is used as a toner for a one-component developer. An image forming method using a photographic toner. [Detailed description of the invention]

Hereinafter, the present invention will be described in detail. The polyester resin used as a binder in the present invention is obtained by condensation polymerization of an alcohol component and a carboxylic acid component. Examples of the alcohol component used include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, , 3-
Diols such as propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, and other divalent Alcohol monomers can be mentioned. Examples of the carboxylic acid component include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, and malonic acid. And acid anhydrides or lower alkyl esters thereof, dimers of linoleic acid, and other divalent organic acid monomers.

The polyester resin used in the present invention includes not only the above-mentioned difunctional monomer, but also a trivalent or higher polycarboxylic acid monomer as a carboxylic acid component of a trifunctional or higher polyfunctional monomer. It is a polymer containing the acid anhydride. Examples of such a polyfunctional monomer which is a trivalent or higher polyvalent carboxylic acid monomer include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4- Cyclohexanetricarboxylic acid, 2,
5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-
Dicarboxyl-2-methyl-2-methylenecarboxylpropane, tetra (methylenecarboxyl) methane,
Examples thereof include 1,2,7,8-octanetetracarboxylic acid, embolic trimer acid, and acid anhydrides thereof. It is necessary that the carboxylic acid component of the above trifunctional or higher polyfunctional monomer be contained in a proportion of 15 to 20 mol%.

The trihydric or higher polyhydric alcohol used in the present invention may be any of those generally known as trihydric or higher polyhydric alcohols. For example, glycerin, 1,
1,1-trimethylolethane, 1,1,1-trimethylolpropane, 1,1,1-trimethylolbutane,
Examples thereof include pentaerythritol, 1,1,2,2-tetramethylolethane, 1,1,3,3-tetramethylolpropane, sorbitol, and polyvinyl alcohol. These are used in one kind or in a mixture of two or more kinds. Among the above-mentioned trihydric or higher polyhydric alcohols, glycerin, 1,1,1-trimethylolpropane, and pentaerythritol are preferred in terms of esterification reactivity and cost. These are used in an amount of 15 to 40 m with respect to the total acid component.
ol% is preferable, and 15 to 30 mol% is particularly preferable in consideration of reaction control.

The production method for obtaining the polyester of the present invention is not particularly limited, and the esterification reaction can be performed by a known method. The transesterification can be performed by a known method, and in this case, a known transesterification catalyst can be used. Examples include magnesium acetate, zinc acetate, manganese acetate, calcium acetate, tin acetate, lead acetate, titanium tetrabutoxide and the like. The polycondensation reaction can be performed by a known method, and in this case, a known polymerization catalyst can be used. Specific examples include antimony trioxide and germanium dioxide.

The binder resin of the present invention is free from THF-insoluble components, has a molecular weight distribution of not more than 500% in the molecular weight distribution by gel permeation chromatography, not more than 4% by weight, and has one peak in the molecular weight region of 3,000 to 9000. It is to have. When the THF-insoluble matter enters, the gloss decreases and the transparency decreases, and OHP
High quality images cannot be obtained when using sheets. When the content of the component having a molecular weight of 500 or less is 4% by weight or more, the blade or the sleeve is contaminated by being used for a long period of time, and filming easily occurs.

The ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of the binder resin of the present invention is preferably 2 to 10. When Mw / Mn exceeds 10, a glossy high-quality image cannot be obtained when the toner is fixed as a toner. Further, when Mw / Mn is less than 2, there is a problem that productivity is reduced in a pulverizing step in producing a toner.

A method has been proposed in which toner particles and inorganic powders such as various metal oxides are added and mixed for use in order to improve the flow characteristics and charging characteristics of the toner. This additive is used as an external additive. is called. In addition, if necessary, a method of treating with a specific silane coupling agent, a titanate coupling agent, a silicone oil, an organic acid, or the like, for the purpose of modifying the hydrophobicity, charging characteristics, etc. of the surface of the inorganic powder, coating with a specific resin A method of doing so has also been proposed.

Examples of the inorganic powder include silicon dioxide (silica), titanium dioxide (titania), aluminum oxide, zinc oxide, magnesium oxide, cerium oxide,
Iron oxide, copper oxide, tin oxide and the like are known. Particularly, silica fine particles obtained by reacting silica or titanium dioxide fine particles with an organic silicon compound such as dimethyldichlorosilane, hexamethyldisilazane, or silicone oil to replace the silanol groups on the surface of the silica fine particles with an organic group and making the silica fine particles hydrophobic are used.

According to the present invention, in the image forming method in which the developing step is to form a thin layer of the developer on the developer carrier and develop it in contact or non-contact with the latent image carrier, at least polyester as the binder resin An electrophotographic toner for a one-component developer comprising a resin and a colorant, wherein the polyester resin has no THF-insoluble content, and has a content ratio of a component having a molecular weight of 500 or less in a molecular weight distribution by gel permeation chromatography. An electrophotographic toner or a weight average molecular weight (Mw) or a number average molecular weight (M) of 4% by weight or less and a polyester resin having one peak in a molecular weight range of 3000 to 9000;
An image forming method is provided, wherein an electrophotographic toner using a polyester resin having a ratio Mw / Mn of n of 2 to 10 is used.

According to the present invention, a latent image forming step of forming a latent image on a latent image holding member, a developing step of developing the latent image using a developer on a developer carrying member, and transferring the developed toner image In an image forming method having a transfer step of transferring onto a body and a fixing step of heating and fixing a toner image on a transfer body, an electrophotographic method comprising at least a polyester resin as a binder resin and a colorant as a developer toner. Toner,
A polyester resin which is free from THF-insoluble components, has a content of a component having a molecular weight of 500 or less in a molecular weight distribution by gel permeation chromatography of 4% by weight or less, and has one peak in a region of a molecular weight of 3000 to 9000; An image characterized by using an electrophotographic toner or an electrophotographic toner using a polyester resin having a ratio Mw / Mn of weight average molecular weight Mw to number average molecular weight Mn of 2 to 10. A method of forming is provided.

Further, according to the present invention, a multi-color developing apparatus including a developing roll and a developing blade for uniformly regulating the layer thickness of the developer supplied on the developing roll is provided.
The multi-colored electrostatic latent image formed on the electrostatic image carrier is developed on a plurality of electrostatic image carriers corresponding to each color by a developer corresponding to each color. In an electrophotographic developing method using an electrophotographic recording device that sequentially transfers the toner image to the transfer material by bringing a transfer unit into contact with the surface of the charge image carrier via a transfer material, the developer toner is What is claimed is: 1. An electrophotographic toner comprising at least a polyester resin as a binder resin and a colorant, wherein the polyester resin has no THF-insoluble content and a content of a component having a molecular weight of 500 or less in a molecular weight distribution by gel permeation chromatography. Is 4% by weight or less and a polyester resin having one peak in a molecular weight region of 3,000 to 9000. Further, the image forming method of the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is characterized by using the electrophotographic toner using the polyester resin is 2 to 10 is provided.

As the coloring agent, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (1
0G, 5G, G), cadmium yellow, yellow iron oxide, ocher, graphite, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow ( G, G
R), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Tan, Lead Zhu, Cadmium Red, Cad Muum Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Phisaed Red, Parachlor Ortho Nitroaniline Red, Risor Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine Min BS, Permanent Red (F2R, F4R, FRL, FRL)
L, F4RH), Fast Scarlet VD, Belcan Fast Rubin B, Brilliant Scarlet G, Lisor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F
2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Museum, Eosin Lake,
Rhodamine lake B, rhodamine lake Y, alizarin lake, thioindigo red B, thioindigo maroon, oil red, 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 (R
S, BC), indigo, ultramarine, navy blue, anthraquinone blue, fast violet B, methyl violet lake, cobalt violet, manganese violet, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Titanium Oxide, Zinc White, Lithobon and mixtures thereof can be used. The amount used is generally 0.1 to 50 parts by weight based on 100 parts by weight of the binder resin.

In order to give the produced developer a releasability, it is preferable to include a wax in the produced developer. The wax has a melting point of 40 to 120.
° C, and particularly preferably 50 to 110 ° C. If the melting point of the wax is too high, the fixability at low temperatures may be insufficient, while if the melting point is too low, the offset resistance and durability may decrease. The melting point of the wax can be determined by differential scanning calorimetry (DSC). That is, the melting peak value when a few mg of the sample is ripened at a constant heating rate, for example (10 ° C./min), is defined as the melting point.

Examples of the wax usable in the present invention include solid paraffin wax, microwax, rice wax, fatty acid amide wax, fatty acid wax, aliphatic monoketones, fatty acid metal salt wax, and fatty acid ester wax. And partially saponified fatty acid ester waxes, silicone varnishes, higher alcohols, carnauba waxes, and the like. Polyolefins such as low molecular weight polyethylene and polypropylene can also be used. In particular, a polyolefin having a softening point of 70 to 150 ° C by a ring and ball method is preferable,
Further, a polyolefin having a softening point of 120 to 150 ° C is preferable.

Examples of the cleaning property improving agent for removing the post-transfer developer remaining on the photoreceptor and the primary transfer medium include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, for example, fine particles of polymethyl methacrylate, Examples include polymer fine particles produced by soap-free emulsion polymerization of polystyrene fine particles and the like. Polymer fine particles have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.
Are preferred.

Next, a method for producing a toner will be described. As a method for producing the toner of the present invention, a step of mechanically mixing a developer component containing at least a binder resin, a main charge control agent and a pigment, a step of melt-kneading, a step of pulverizing, and a step of classifying Can be applied. In addition, in the step of mechanically mixing or the step of melt-kneading, powder other than the particles serving as products obtained in the step of pulverization or classification may be returned and reused.

The powder (by-product) other than the particles to be the product referred to here is subjected to the step of melt-kneading, and then to the fine particles and coarse particles other than the components to be the products having the desired particle diameters obtained in the pulverizing step, and subsequently. It means fine particles and coarse particles other than the components that are generated in the classification step and have a desired particle size. In the mixing step or the melt-kneading step of such a by-product, it is preferable to mix the raw material and preferably the by-product 1 at a weight ratio of the other raw material 99 to the by-product 50 to the by-product 50. At least a binder resin, a main charge control agent and a pigment,
The mixing step of mechanically mixing the developer components including the by-products may be performed under ordinary conditions using a conventional mixer or the like using rotating blades, and is not particularly limited.

After the above-mentioned mixing step is completed, the mixture is then charged into a kneader and melt-kneaded. As the melt kneader, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. For example, a KTK twin screw extruder manufactured by Kobe Steel, a TEM extruder manufactured by Toshiba Machine Co., a twin screw extruder manufactured by KCK, a PCM twin screw extruder manufactured by Ikegai Iron Works, Bus A co-kneader or the like is preferably used. It is important that the melt-kneading is performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be cut. Specifically, the melt-kneading temperature should be determined with reference to the softening point of the binder resin. If the temperature is lower than the softening point, cutting is severe, and if the temperature is too high, dispersion does not proceed.

After the completion of the above-mentioned melt-kneading process, the kneaded material is then pulverized. In this pulverization step, it is preferable to first perform coarse pulverization and then finely pulverize. In this case, a method of crushing by colliding with a collision plate in a jet stream, crushing by colliding particles in a jet stream, or crushing by a narrow gap between a mechanically rotating rotor and a stator is preferably used.

After the completion of the pulverizing step, the pulverized product is classified in an air stream by centrifugal force or the like, thereby producing a developer having a predetermined particle size, for example, an average particle size of 5 to 20 μm. Further, when preparing the developer, the hydrophobic silica fine particles mentioned above are further added to the developer manufactured as described above in order to enhance the fluidity, preservability, developability and transferability of the developer. Inorganic fine particles such as powder may be added and mixed.

For mixing the external additive, a general powder mixer is used, but it is preferable to equip a jacket or the like so that the internal temperature can be adjusted. In order to change the history of the load applied to the external additive, the external additive may be added during or gradually. Of course, the rotation speed, rolling speed, time, temperature, etc. of the mixer may be changed. A strong load may be applied first, followed by a relatively weak load, or vice versa. Examples of mixing equipment that can be used include a V-type mixer, a rocking mixer, a Lodige mixer, a Nauta mixer,
Henschel mixer and the like.

The magnetic carrier may have a particle size of 20 to 20.
Conventionally known materials such as iron powder, ferrite powder, magnetite powder and magnetic resin carrier of about 0 μm can be used.
Further, as the coating material, an amino resin, for example, urea-
Examples include a formaldehyde resin, a melamine resin, a benzoguanamine resin, a urea resin, a polyamide resin, and an epoxy resin. Also, polyvinyl and polyvinylidene resins, for example, acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins such as polystyrene resins and styrene acrylic copolymer resins, polychlorinated resins Halogenated olefin resin such as vinyl, polyester resin such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride Fluoro terpolymers such as terpolymers, etc. and non-fluoride monomers including the can be used, the silicone resin is excellent in terms of developer life and.

If necessary, a conductive powder or the like may be contained in the coating resin. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide and the like can be used. These conductive powders preferably have an average particle size of 1 μm or less. When the average particle size is larger than 1 μm,
It becomes difficult to control the electric resistance.

Next, a full-color image developing method will be described. In the non-magnetic one-component developing method using a conductive brush according to the present invention, the non-magnetic one-component developing method uses a full-color toner having a specific degree of circularity to sequentially perform development many times, and sequentially superimposes and transfers onto a transfer medium. In a component full-color process, the effect can be effectively utilized particularly for uniform reproducibility of halftone.

The full-color non-magnetic one-component image forming method of the present invention is achieved by a multi-color developing apparatus having a developing roller and a developing blade for uniformly regulating a layer thickness of a developer supplied on the developing roller. In this method, an electrostatic latent image divided into each color is sequentially developed on a plurality of photoconductors corresponding to each color by a developer of a color corresponding to each color, and is transferred to a transfer medium.

In this case, it is preferable that the developing is performed by a reversal developing method in which the polarity of the electrostatic latent image on the photosensitive member and the polarity of the non-magnetic one-component developer are the same. Further, it is preferable that the developing is performed by rotating the developing roller at a higher speed than the photoconductor by directly contacting the electrostatic latent image on the photoconductor with the developing roller.

[0039]

The present invention will be described below in detail with reference to examples. In addition, the physical property of the polyester resin in an Example and a comparative example was measured by the following measuring methods. The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (HCL-8200 manufactured by Tosoh Corporation) as follows. Stabilize the column in a heat chamber at 40 ° C., and add TH as a solvent to the column at this temperature.
F at a flow rate of 1 ml / min.
A THF sample solution of the resin adjusted to 0.6% by weight
Measure by injecting ~ 200 μl. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical
Co. or Toyo Soda Kogyo Co., Ltd. has a molecular weight of 6 × 1
0 ² , 1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ ,
1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2
It is appropriate to use a sample of × 10 ⁶ and 4.48 × 10 ⁶ and use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.
The present invention is not limited to only these examples. In the following examples, parts and percentages are by weight unless otherwise specified.

<Example 1> A magenta base toner A was obtained by blending the following components. Binder resin 100 parts of polyester resin a (molecular weight 500 or less: 2%) (molecular weight peak: 6500) (Mw / Mn: 5.9) Coloring agent Quinacridone-based magenta pigment 4 parts Charge control agent Salicylic acid zinc compound 4 parts

<Example 2> A magenta base toner B was obtained by blending the following components. Binder resin Polyester resin b 100 parts (Molecular weight 500 or less: 2.4%) (Molecular weight peak: 7500) (Mw / Mn: 3.0) Colorant Quinacridone-based magenta pigment 4 parts Charge control agent Salicylic acid zinc compound 4 parts

Example 3 A magenta base toner C was obtained by blending the following components. Binder resin 100 parts of polyester resin c (molecular weight 500 or less: 2.2%) (molecular weight peak: 6800) (Mw / Mn: 9.5) Coloring agent Quinacridone-based magenta pigment 4 parts Charge control agent Salicylic acid zinc compound 4 parts

Comparative Example 1 A magenta base toner D was obtained by blending the following components. Binder resin Polyester resin d 100 parts (Molecular weight 500 or less: 3.8%) (Molecular weight peak: 9700) (Mw / Mn: 1.7) Coloring agent Quinacridone-based magenta pigment 4 parts Charge control agent Salicylic acid zinc compound 4 parts

Comparative Example 2 A magenta base toner E was obtained by blending the following components. Binder resin Polyester resin e 100 parts (Molecular weight 500 or less: 4.4%) (Molecular weight peak: 6500) (Mw / Mn: 5.7) Coloring agent Quinacridone-based magenta pigment 4 parts Charge control agent Salicylic acid zinc compound 4 parts

Example 4 A magenta base toner F was obtained by blending the following components. Binder resin 100 parts of polyester resin f (molecular weight 500 or less: 2.8%) (molecular weight peak: 6500) (Mw / Mn: 1.8) Coloring agent Quinacridone-based magenta pigment 4 parts Charge control agent Salicylic acid zinc compound 4 parts

Comparative Example 3 A magenta base toner G was obtained by blending the following components. Binder resin polyester resin g 100 parts (molecular weight 500 or less: 2.7%) (molecular weight peak: 2600) (Mw / Mn: 10.5) Coloring agent Quinacridone-based magenta pigment 4 parts Charge control agent Salicylic acid zinc compound 4 parts

The images obtained using the toners of the above Examples and Comparative Examples were evaluated for the following evaluation items using various image evaluation machines. The evaluation results are shown in [Table] below. (Evaluation item)

<Filming> An image chart having a 5% image area was continuously run up to 100,000 sheets using a full-color laser printer, Ipsio 5000 (manufactured by Ricoh Co., Ltd.), and evaluated. The occurrence of toner filming on the developing roller or the photoconductor was observed.が indicates no filming, Δ indicates filming on streaks, and × indicates filming as a whole. Only the filming evaluation was performed using a modified machine (sleeve linear speed 300 mm / se).
The same evaluation was performed in c). (Comparative Examples 5 to 8)

<Transparency> 1 at a fixing speed of 90 mm / sec.
At 60 ° C., samples were prepared with OHP sheets. This was measured for transparency using a haze meter (Suga Test Machine Co., Ltd.). ○, 30 with haze degree of 15% or less
% Or less and 30% or more were evaluated as x.

<Glossiness> Toner development amount is 1.0 mg / c
m 2 was fixed at 160 ° C., and these fixed image samples were adjusted to a light emitting angle and a light receiving angle of 60 ° C. using a gloss meter (VG-1D) (manufactured by Nippon Denshoku Co., Ltd.).
The 0-switch SW was set to S, the 0 preparation and the standard plate were used, and after setting the standard, the image was placed on the sample table and measured.
の も の for glossiness of 20% or more, × for less than 20%
Was evaluated.

<Pulverizability> The kneaded material was adjusted with a collision mill (I-2 type mill, manufactured by Nippon Pneumatic Industries, Ltd.) using a jet mill to obtain colored particles having a volume average diameter of 6.5 μm. At that time, the pulverization amount per unit time (Kg / H) was measured. 2.0 (Kg / H) or more was rated as ○, and less than 2.0 (Kg / H) was rated as x.

[0052]

[Table 1]

As is clear from the results shown in the above table, when the polyester resin as the binder resin of the electrophotographic toner satisfies the molecular weight requirement specified in the present invention, the electrophotographic toner is filled. It can be seen that the film has excellent image quality, image transparency and glossiness.

[0054]

According to the present invention, after continuous printing for a long period of time, there is no filming on the photosensitive member, the developer layer thickness regulating member or the developing sleeve, and the high quality output image equivalent to the initial image can be maintained. A photographic toner is obtained. Because of this long-term durability, the life of the developing unit and photoreceptor unit can be prolonged, and the amount of recyclables and waste generated after use is small, and the user has less trouble replacing these image forming units. It becomes possible to do. Furthermore, in the production step of pulverizing the toner, an electrophotographic toner having good productivity can be obtained.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroyuki Fushimi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Osamu Uchinokura 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Shinichiro Yagi 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (Reference) 2H005 AA01 CA08 EA06 2H077 AD02 AD06 AD13 AD23 BA03 EA14 EA15 EA16 GA03 GA13

Claims (7)

[Claims] 1. An electrophotographic toner for a one-component developer comprising at least a polyester resin as a binder resin and a colorant, wherein the polyester resin has no THF-insoluble content and is free from gel permeation chromatography. In the molecular weight distribution, the content of the component having a molecular weight of 500 or less is 4% by weight or less, and the molecular weight is 3000 to 9000.
Characterized in that it is a polyester resin having one peak in the region of 2. The polyester resin has a weight average molecular weight Mw.
2. The electrophotographic toner according to claim 1, wherein the ratio Mw / Mn of the number average molecular weight Mn to Mw / Mn is 2 to 10. 3. A one-component developing method using the toner for electrophotography according to claim 1, comprising a conveying member, a toner layer thickness regulating member, and a toner replenishment auxiliary member, and further comprising a toner layer thickness regulating member. Using a developing device in which the member and the toner conveying member are in contact with each other, supplying the thinned toner on the toner conveying member to the surface of the electrostatic latent image carrier to develop the latent image. one-component developing method of. 4. The one-component developing method according to claim 3, wherein the toner conveying member is rotated at a speed of 160 mm / sec or more and 280 mm / sec or less. 5. A latent image forming step of forming a latent image on a latent image holding member, a developing step of developing the latent image using a developer on a developer carrier, and a step of transferring the developed toner image onto a transfer member. 3. An image forming method comprising a transfer step of transferring to a toner image and a fixing step of heating and fixing a toner image on a transfer body, wherein the toner for electrophotography according to claim 1 or 2 is used as a toner for a one-component developer. Image forming method. 6. The image forming method according to claim 5, wherein in the developing step, a thin layer of the developer is formed on the developer carrying member, and the developing is performed in contact with or not in contact with the latent image holding member. 7. A multi-color developing device provided with a developing roller and a plurality of multi-color developing devices having a regulating member for uniformly regulating a layer thickness of a developer supplied on the developing roll, the multi-color formed on the electrostatic image carrier. The electrostatic latent image divided into a plurality of electrostatic latent images is developed on a plurality of electrostatic image carriers corresponding to each color by a developer corresponding to each color, and is transferred to the surface of the electrostatic image carrier via a transfer material. 3. An electrophotographic developing method using an electrophotographic recording apparatus for sequentially electrostatically transferring the toner image to the transfer material by contacting means, wherein the toner is a toner for a one-component developer. An image forming method characterized by using a toner for printing.