JP2000298394A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method by which a developer is stably conveyed over a long period of time and a stable image free from unevenness in image density and excellent in image quality and fixability is obtained. SOLUTION: The image forming method includes a latent image forming step, a developer conveying step and a developing step. The developer has at least a toner and the surface of a developer support satisfies the relation of 200 >=Rz×20>=Sm [where Rz is ten-point average roughness (μm) and Sm is the average spacing between protrusions]. Toner particles in the toner contain 1 to 15 wt.% wax, the area proportion of the wax exposed to the surfaces of the toner particles is <=50% and the proportion of particles having <=4 μm in the particle size distribution of the toner particles is <=20 number %. The toner may consist of toner particles containing at least a wax, fine particles having 20 to 100 mμm number average particle diameter and abrasive grains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method utilizing an electrophotographic method and an electrostatic recording method. More specifically, the present invention relates to an image forming method for developing an electrostatic latent image formed on a surface of an electrostatic latent image carrier using a developer carried on the surface of the developer carrier.

[0002]

2. Description of the Related Art Conventionally, when an image is formed in a copying machine, a laser beam printer or the like, the Carlson method is generally used. In a conventional image forming method, an electrostatic latent image formed on the surface of a photoconductor (electrostatic latent image carrier) by optical means or the like is developed in a developing process, and then is transferred to a recording medium such as a recording paper in a transfer process. And then fixed to the recording medium in a fixing step, typically by heat and pressure. Since the photoconductor is used repeatedly, a cleaning device is provided to remove residual toner remaining on the surface of the photoconductor after the transfer process.

There are two types of developing methods used for developing the electrostatic latent image: a one-component developing method using only toner and a two-component developing method using a two-component developer composed of toner and carrier. In the component development method, the toner is frictionally charged by stirring the toner and the carrier.
By selecting the characteristics of the carrier and the stirring conditions, the amount of triboelectric charge of the toner can be controlled to a considerable extent, so that it has excellent characteristics such as high image quality reliability.

On the other hand, a toner used in an electrophotographic process is generally a binder resin (for example, a polyester resin,
Styrene-acrylic resin, epoxy resin, etc.), add a colorant, a charge control agent, a release agent, etc., melt-knead them, uniformly disperse them, pulverize them to a predetermined particle size, and then use a classifier to excess It can be obtained by a pulverization / classification process for removing fine dust and fine powder.

In recent years, with the demand for higher image quality, it has been desired to reduce the particle size of the toner. In addition, from the demand for energy saving, it is desired that the binder resin has a low glass transition and a low softening point so that the binder resin can be fixed at a lower temperature.

On the other hand, in a color toner mounted on a full-color copying machine or a printer, it is necessary to sufficiently mix multicolored color toners in a fixing process. At this time, color reproducibility and transparency of an OHP image are important. It is becoming. In order to enhance the color mixing property of the color toner, it is generally desired to use a sharp-melt low-molecular-weight resin as the binder resin as compared with the black toner.

Conventionally, a black toner having a relatively high melting point, such as polyethylene or polypropylene, having high crystallinity has been used to obtain offset resistance during fixing. When such a high melting point wax is used, the transparency of the OHP image is impaired.

[0008] For this reason, ordinary full-color color toners do not contain wax, and in order to obtain offset resistance at the time of fixing, the surface of the heat-fixing roller is made of silicone rubber or fluorine which has excellent releasability from the toner. Formed of resin,
Further, a method of supplying a releasing liquid such as silicone oil to the surface is adopted. Although this method is extremely effective in preventing the offset phenomenon of the toner, it has a problem that an apparatus for supplying the release liquid is required. This is contrary to the recent reduction in size and weight of the device, and the release liquid may be heated to evaporate to give an unpleasant odor, or may cause contamination in the device.

Therefore, a toner having a small particle size, which is formed by a pulverizing / classifying method and is composed of a sharp-melting binder resin, a colorant, and a low-melting wax, is being studied.

Further, in order to give the toner itself an offset resistance at the time of fixing so that the transparency of the OHP image is not impaired, a method of limiting the viscosity of the toner (JP-A-1-133)
Nos. 065, 2-161466, 2-10
No. 0059, No. 3-229265), a method of incorporating a wax such as a releasable resin into the toner (Japanese Patent Publication No. 52-3304), and a method of limiting the melt viscosity of the wax (Japanese Unexamined Patent Publication No. No. 260659, 3-1
No. 22660), a method of limiting the diameter of the wax domain and the abundance of the wax on the toner surface (JP-A-7-8)
No. 4398) and a method of limiting the shape of a wax domain (Japanese Patent Laid-Open No. 6-161145) has been proposed.

When a two-component developer having such a toner and a carrier is carried on the surface of a developer carrying member, and the electrostatic latent image on the surface of the electrostatic latent image carrying member is developed, the developer is usually used. The developer layer regulating member opposing the carrier forms an appropriate and uniform developer layer on the developer carrier, and is conveyed to the developing area.

However, when a two-component developer having the above-mentioned toner is used in a developing device having such a developer layer regulating member, when the image is repeatedly formed, the toner becomes a conventional black toner. Since the toner is more easily deformed than the color toner containing no toner or wax, and contains a large amount of small particle size toner, and the small particle size toner has relatively increased adhesiveness, the toner is subjected to a mechanical load so that the developer carrier The developer is adhered so as to be rubbed on the surface, so that the surface of the developer carrying member becomes contaminated. This is probably because the toner has an exposed portion of the wax on its surface.

As the contamination of the surface of the developer carrier progresses, the amount of the developer carried on the surface of the developer carrier changes, and the amount of toner used for development also changes. Density unevenness appears inside the printed image, which degrades the print image quality.

In order to improve the problem of the toner contamination on the surface of the developer carrying member, a method of polishing the surface of the developer carrying member with large spherical particles has been proposed (Japanese Patent Laid-Open No. 5-19632). I have. However, in the case of a developer containing a toner composed of a sharp-melting binder resin and a low-melting-point wax, although the effect is initially effective when the image repetition durability test is carried out, after the test, it is effective on the surface of the developer carrier after the test. Contamination was observed. In addition, a method of using a spherical toner and defining a center line average roughness (Ra) and an average interval (Sm) of irregularities on the surface of the developer carrying member (Japanese Patent Laid-Open No. 8-15979).
Japanese Patent Application Laid-Open No. H11-176,878), although uniform developer transport was achieved by this method, contamination was observed on the surface of the developer carrier after the test.

[0015]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming method capable of stably transporting a developer over a long period of time, having no image density unevenness, having excellent image quality and fixing properties, and obtaining a stable image. Is to provide.

[0016]

Means for Solving the Problems The present inventors have intensively studied and studied from a different point of view in order to improve the above-mentioned disadvantages in the prior art, and as a result, the following first present invention, Alternatively, by adopting the configuration of the second aspect of the present invention, the above-mentioned problem has been successfully solved.

According to a first aspect of the present invention, at least a latent image forming step of forming an electrostatic latent image on a surface of an electrostatic latent image carrier, and a developing step of carrying a developer on the surface of the developer carrier and transporting the developer to a developing area An image forming method comprising: a developer transporting step; and a developing step of developing an electrostatic latent image on the surface of the electrostatic latent image carrier with a developer carried on a surface of the developer carrier in a developing area. The developer has a toner comprising at least toner particles, the toner particles contain at least 1 to 15% by weight of a wax, and the exposed area ratio of the wax on the surface of the toner particles is 50% or less; In the particle size distribution of toner particles, the ratio of 4 μ or less is 20% by number.
Wherein the surface of the developer carrying member has the following formula (1)
Which satisfies the following relationship:

200 ≧ Rz × 20 ≧ Sm (1) In the above formula (1), Rz represents the ten-point average roughness (μm) of the surface of the developer carrier, and Sm is the surface roughness of the developer carrier. Indicates the average interval (μm) of the unevenness.

According to the image forming method of the first aspect of the present invention, when the developer carried on the developer carrier is transported to the developing zone, uniform and stable transport over a long period of time is possible. Since the contamination of the body surface with the toner component is suppressed, there is no problem in developability in the development area for a long period of time, and a high-quality image without image density unevenness can be stably obtained.

According to a second aspect of the present invention, at least a latent image forming step of forming an electrostatic latent image on the surface of an electrostatic latent image carrier, and a developing step of carrying a developer on the surface of the developer carrier and transporting the developer to a developing area An image forming method comprising: a developer transporting step; and a developing step of developing an electrostatic latent image on the surface of the electrostatic latent image carrier with a developer carried on a surface of the developer carrier in a developing area. The developer comprises a toner, and the toner comprises toner particles containing at least wax, fine particles having a number average particle diameter of 20 nm or more and 100 nm or less, and abrasive particles, and the surface of the developer carrier is , The following equation (1)
Which satisfies the following relationship:

200 ≧ Rz × 20 ≧ Sm (1) In the above formula (1), Rz represents the ten-point average roughness (μm) of the surface of the developer carrier, and Sm is the surface roughness of the developer carrier. Indicates the average interval (μm) of the unevenness.

According to the image forming method of the second aspect of the present invention, when the developer carried on the developer carrier is transported to the developing zone, uniform and stable transport over a long period of time is possible. Since the contamination of the body surface by the toner component is suppressed, there is no problem in the developing property in the developing region over a long period of time, and it is possible to stably obtain a high-quality image without image density unevenness.

In the second aspect of the present invention, the toner particles are composed of at least a binder resin, a colorant, and a wax, and the melt viscosity of the toner is in a range of 80 to 120 ° C. It is preferably 10 ³ to 10 ⁶ poise. Further, in the second invention, the fine particles are:
It is preferably inorganic fine particles, and more preferably silica.

In the present invention (hereinafter, simply referred to as "the present invention" means both "the first present invention" and "the second present invention"), the developer carrying The ten-point average roughness Rz of the body surface is preferably 0.5 μm or more, and the surface of the developer carrying member is preferably polished with glass beads.

In the present invention, the melting point of the wax is preferably in the range of 80 to 120 ° C., and the melt viscosity of the wax at 120 ° C. is preferably 200 centipoise or less.

Further, in the present invention, the toner is preferably a color toner, and the volume average particle diameter of the toner particles is preferably in a range of 3 to 10 μm. It is preferable that the binder resin includes a resin, a colorant, and a wax, and the binder resin is a polyester.

The above-mentioned "first invention" and "second invention" alone can sufficiently achieve the effects aimed at by the present invention, respectively, but "the first invention" and "the second invention" With the configuration having both of the configurations of the "second invention", it is possible to achieve the effect aimed at by the invention at a higher level.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below for each configuration. 1. Configuration Common to First and Second Inventions [Developer Carrier] In the present invention, the surface of the developer carrier satisfies the relationship of the following formula (1). 200 ≧ Rz × 20 ≧ Sm (1) In the above formula (1), Rz represents a ten-point average roughness (μm) of the surface of the developer carrying member, and Sm is an average of irregularities on the surface of the developer carrying member. Indicates the interval (μm).

The details of the ten-point average roughness Rz and the average interval Sm of irregularities are specified in JIS B0601. When using a developer carrier having a relatively large surface roughness as described above, if the toner to be used has a large amount of fine powder components, the toner having a small particle diameter is fused to the concave portion on the surface of the developer carrier, and development is performed. Although the surface of the developer carrier is contaminated, the particle size distribution of the toner used in the present invention is appropriately controlled as described later, and the surface of the developer carrier is not contaminated.

Rz × 20>Sm> 200 or Rz × 20>
In the case of the developer carrying member having a surface condition of 200> Sm, the unevenness of the surface of the developer carrying member becomes very large with respect to the toner particles having a small particle diameter (described later) targeted in the present invention. In some cases, toner adheres so that the toner is embedded in the concave portions of the unevenness, and the surface of the developer carrying member may be contaminated with the toner.

On the other hand, in the case of a developer carrier having a relatively small surface roughness satisfying the relationship of Rz × 20 ≦ Sm, the toner is difficult to adhere to the surface of the developer carrier due to the smoothness of the surface, and the toner is contaminated. However, it is difficult to use a control technique for uniformly forming small irregularities on the surface of the developer carrying member, and it is difficult to use it in terms of cost. Further, in the second aspect of the present invention, abrasion of the surface of the developer carrier by abrasive particles (described later) partially occurs due to long-term use, and eventually, uneven transport of the developer occurs, and Density unevenness is observed in the middle solid image. The ten-point average roughness Rz of the surface of the developer carrier is 0.5 μm
The above conditions are preferable in that the toner layer can be uniformly and stably formed on the surface of the developer carrying member.

As a method of roughening the surface of the developer carrying member to the above-mentioned predetermined surface condition defined in the present invention, for example, a sand blast method of polishing the surface using irregular particles or regular particles as abrasive grains, Sandpaper method in which the surface of the developer carrier is rubbed in a predetermined direction with sandpaper having irregularities formed in the circumferential direction of the sleeve, a method by chemical treatment, a method of forming a convex portion on the coated resin layer after coating with a resin, etc. Can be mentioned.

In the present invention, it is preferable that the roughened surface of the developer carrier does not have sharp projections. By using the developer carrier having such a surface state, fusing and contamination of toner become remarkable. Can be suppressed. In order to obtain such a surface state, it is preferable to adopt a sand blast method of polishing the surface using spherical glass beads as abrasive grains as a surface roughening method.

As a material of the developer carrying member in the present invention, a known material can be used. For example, metals such as aluminum, stainless steel and nickel; those coated with carbon, resin elastomer and the like; natural rubber;
An elastic body such as silicone rubber, urethane rubber, butadiene rubber, or chloroprene rubber processed into a non-foamed, foamed or sponge form; carbon, resin elastomer processed on these non-foamed, foamed or sponge form And the like; and the like.

The shape of the developer carrying member in the present invention is not particularly limited, and examples thereof include a cylindrical shape and a sheet shape. In the case of a so-called developing sleeve in which the developer carrying member is cylindrical, the diameter is 10 mm to 3 mm.
It is preferably 5 mm in terms of development efficiency and suppression of toner fusion, and more preferably 15 mm to 27 mm. When a two-component developer of a non-magnetic toner and a magnetic carrier is used as the developer, a magnetic field generating means such as a magnet is included inside the developer carrier.

[Developer] The developer used in the present invention has a toner composed of at least toner particles (a portion of the toner excluding external additives, ie, a toner particle main body).

A) Toner The toner of the present invention comprises at least toner particles and, if necessary, other external additives (in the second present invention, fine particles and abrasive particles are essential components.
This will be described later. ). The toner particles include at least a binder resin, a colorant, and a wax.

The binder resin is not particularly limited, but styrenes such as styrene and chlorostyrene,
Monoolefins such as ethylene, propylene, butylene and isoprene, vinyl acetate, vinyl esters such as vinyl propionate, vinyl benzoate and vinyl acetate, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, A-methylene aliphatic monocarboxylic acid esters such as phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate, vinyl ether such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether, vinyl methyl ketone, and vinyl Homopolymers or copolymers of vinyl ketone such as hexyl ketone and vinyl isopropenyl ketone can be exemplified. Particularly typical binder resins include polystyrene and styrene-acrylic acid. Kill copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene, polypropylene, and the like. , Polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin, and wax. Among these, it is particularly effective for the present invention to use polyester as the binder resin. For example, a linear polyester resin comprising a polycondensate containing bisphenol A and a polyvalent aromatic carboxylic acid as main monomer components can be preferably used.

The polyester resin used as the binder resin in the present invention is synthesized from a polyol component and a polycarboxylic acid component by polycondensation. Examples of the polyol component used include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3 butanediol, diethylene glycol, triethylene glycol, 1,5-butanediol,
6-hexanediol, neopentyl glycol, cyclohexanedimethanol, hydrogenated bisphenol A, bisphenol-A ethylene oxide adduct, bisphenol-A propylene oxide adduct, and the like. As the polyol component, maleic acid, fumaric acid,
Phthalic acid, isophthalic acid, terephthalic acid, succinic acid, dodecenylsuccinic acid, trimellitic acid, pyromellitic acid,
Cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropanetetramethylenecarboxylic acid and And their anhydrides.

In the present invention, the binder resin includes a softening point of 90 to 150 ° C., a glass transition point of 55 to 75 ° C., a number average molecular weight of 2000 to 6000, and a weight average molecular weight of 8000 to 1
Resins showing 50,000, an acid value of 5 to 30, and a hydroxyl value of 5 to 40, respectively, are particularly preferred.

The colorant is not particularly limited, but includes carbon black, nigrosine, aniline blue, calcoil blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow,
Methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, C.I. I. Pigment Red 48: 1,
C. I. Pigment Red 122, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Yellow 9
7, C.I. I. Pigment Yellow 12, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 15: 3 and the like can be exemplified.

The problem of contamination due to toner adhesion to the developer carrying member was particularly remarkable in a so-called color toner using colored particles other than black. However, it is possible to provide an image forming method in which contamination of the developer carrier is suppressed, stable developer transport over a long period of time, no image density unevenness, excellent image quality, excellent fixability, and a stable image can be obtained. . In the case of a black toner, since carbon black is generally used as a colorant, the electrostatic adhesion to a developer carrier is weak, and contamination is unlikely to occur.

The amount of the colorant to be added is not particularly limited, and may be appropriately selected depending on the type of the colorant to be used, the desired color density, and the like. About 20% by weight, more preferably about 3 to 12% by weight.

In the present invention, wax must be contained in the toner particles in order to impart offset resistance to the toner itself. In recent years, full-color copying machines,
In the printer, in the fixing process, an anti-offset liquid is supplied to the heat fixing roll to prevent contamination and offset of the roll, but a mechanism for that is required, which makes the apparatus smaller and lighter. In the opposite direction to In addition, the offset prevention liquid may be heated and evaporated to give an unpleasant odor, or may cause contamination in the machine. Accordingly, in the present invention, a wax is contained in the toner particles in order to obtain good fixability in a state where no anti-offset liquid is used in the fixing step or in a case where the anti-offset liquid is used in an extremely small amount.

Examples of the wax used in the present invention include paraffin wax and its derivatives, montan wax and its derivatives, microcrystalline wax and its derivatives, Fischer-Tropsch wax and its derivatives, and polyolefin wax and its derivatives. Derivatives include oxides, polymers with vinyl monomers, and graft-modified products. In addition, alcohols, fatty acids, vegetable waxes, animal waxes, mineral waxes, ester waxes, acid amides and the like can also be used.

The wax used in the present invention has an endothermic onset temperature of 4 on a DSC curve measured by a differential scanning calorimeter.
0 ° C. or higher, more preferably 50 ° C.
That is all. If the temperature is lower than 40 ° C., toner aggregation may occur in a copying machine or a toner bottle. The endothermic onset temperature depends on the low molecular weight one of the molecular weight distributions constituting the wax and the type and amount of the polar group having the structure. In general, when the molecular weight is increased, the endothermic onset temperature increases with the melting point, but this method impairs the inherent low melting temperature and low viscosity of the wax. Therefore, it is effective to select and remove only those having a low molecular weight in the molecular weight distribution of the wax. Examples of the method include methods such as molecular distillation, solvent separation, and gas chromatography.

The wax used in the present invention has a melting point of 8
It is preferably in the range of 0 to 120 ° C, more preferably in the range of 80 to 100 ° C. When the melting point is less than 80 ° C., the change temperature of the wax is too low, the blocking resistance is poor, and the developing property is deteriorated when the temperature in the apparatus is increased. If the temperature exceeds 120 ° C., the change temperature of the wax is too high, and there is no problem if fixing is performed at a high temperature, but this is not desirable from the viewpoint of energy saving.

Further, the wax used in the present invention may be selected from the group consisting of 12
The melt viscosity at 0 ° C. is preferably 200 centipoise or less, more preferably 1 to 200 centipoise, and further preferably 1 to 100 centipoise.
It is within the range of centipoise. If the melt viscosity is higher than 200 centipoise, the elution from the toner is weak, and the fixing and releasability may be insufficient.

In the present invention, the melt viscosity of the wax was measured using a kinematic viscometer (Cannon-Phenonsuke viscometer: Shibata Kagaku Kikai Co., Ltd.). Specifically, it is as follows. The kinematic viscometer was set so that the outflow time was 200 seconds or longer, and the molten wax to be measured was placed in a thermostat kept at the temperature of the measurement target (120 ° C.). After allowing the wax and the kinematic viscometer to stabilize at the temperature to be measured after standing for 10 minutes or more, the wax was sucked up and allowed to flow down, and the flowing time was measured to calculate the melt viscosity.

The amount of the wax used in the present invention added to the toner particles will be described later. Toner particles include
In addition to the binder resin, the colorant, and the wax, one or more charge control agents that adjust the charge amount of the toner may be included as an internal additive. Further, a petroleum-based resin may be contained in order to satisfy the pulverizability and heat preservability of the toner particles. The petroleum-based resin is synthesized from diolefins and monoolefins contained in a cracked oil fraction by-produced from an ethylene plant that produces ethylene, propylene, etc. by steam cracking of petroleum. By using a petroleum-based resin and a wax for preventing offset, the petroleum-based resin acts as a wax dispersing agent, so that the dispersion of the wax in the binder resin is remarkably improved, and the wax on the surface of the toner particles is dispersed. Exposure rate can be reduced. As a result, the offset resistance is significantly improved while maintaining the low-temperature fixability, and the pulverizability is good.
It is also possible to improve the occurrence of image defects due to wax filming on the electrostatic latent image carrier and the deterioration of charging due to impact on the carrier.

The volume average particle diameter of the toner particles used in the present invention is preferably in the range of 3 to 10 μm because of the recent demand for smaller toner particles for higher image quality. Preferably, it is more preferably in the range of 3 to 9 μm, even more preferably in the range of 4 to 9 μm. If the volume average particle diameter of the toner particles is larger than 10 μm, reproducibility of fine lines of an image becomes insufficient, and it is difficult to achieve high image quality. On the other hand, if it is smaller than 3 μm, the electrostatic adhesion becomes larger than the gravity, and it becomes difficult to handle as a powder.

In the toner particles used in the present invention,
The addition of the internal additive to the inside of the toner particles is performed by a kneading process. The kneading at this time can be performed using various types of heating kneaders. As a heating kneader, a three-roll type, a single screw type, a twin screw type, a Banbury mixer type and the like are known.

The method for producing the toner particles used in the present invention is not particularly limited. The pulverization of the kneaded material can be performed by a pulverizer such as a micronizer, Ulmax, Jet-o-mizer, KTM (Krypton), and a turbo mill. Furthermore, it can be carried out by I-type Jet-Mill. Classification of the crushed pulverized material, for example, elbow jet using the COANDER effect,
A wind classifier can be used. Further, as subsequent steps, a hybridization system (manufactured by Nara Machinery Works), a mechanofusion system (manufactured by Hosokawa Micron), a crypton system (manufactured by Kawasaki Heavy Industries)
The shape can be changed using, for example. In addition, spheroidization or the like by hot air can be performed.

Further, in order to further improve the long-term storage property, fluidity, developability and transferability of the toner, the toner used in the present invention (the second present invention is a feature of the present invention). Fine particles and abrasive particles), inorganic powders,
Resin powder may be added alone or in combination. As the inorganic powder, for example, carbon black, silica, alumina,
Titania, zinc oxide, etc .;
Spherical particles such as MA, nylon, melamine, benzoguanamine, and fluorine, and amorphous powders such as vinylidene chloride and metal salts of fatty acids. When these inorganic powders and resin powders are added, the respective addition amounts are preferably 0.2 to 4% by weight, more preferably 0.5 to 3% by weight, based on the toner particles. It is.

B) Carrier The developer in the present invention can be a two-component developer comprising the toner and the carrier. The carrier that can be used in the present invention is not particularly limited as long as it is a known carrier, for example, an iron powder-based carrier, a ferrite-based carrier, or a surface-coated ferrite carrier,
Any carrier such as a magnetic material-dispersed carrier can be used without any problem.

The mixing ratio (weight ratio) of the toner and the carrier of the developer used in the present invention is in the range of toner: carrier = 1: 100 to 30: 100, preferably 3: 100 to 20: The range is about 100.

2. Configurations Specific to the First Present Invention In the first present invention, in addition to the configurations common to the present invention described above, toner particles in the toner are as follows:
It has a unique configuration.

When the amount of wax added in the toner particles is 1 to
It contains 15% by weight. In the first aspect of the present invention, the amount of the wax added to the toner particles is 1 to 15% by weight, more preferably 1 to 10% by weight, and still more preferably 3 to 10% by weight.
-10% by weight. If the amount of the wax is less than 1% by weight, sufficient fixing latitude (the temperature range of the fixing roll in which the toner image can be fixed without offsetting the toner) cannot be obtained. As the amount of wax increases, contamination of the surface of the developer carrying member easily occurs.

The exposed area ratio of the wax on the surface of the toner particles is 50% or less. In the first aspect of the present invention, the exposed area ratio of the wax on the surface of the toner particles is 50% or less, and more preferably 30% or less. If the exposed area ratio of the wax is more than 50%, the amount of the wax detached and released from the toner particles increases, or the adhesion strength between the developer carrier surface and the toner is affected by the wax exposed on the toner surface. Because the toner is fused to the surface of the developer carrier due to the influence of the increase, the contamination of the surface of the developer carrier is likely to occur. Further, the powder fluidity of the toner may be deteriorated, and free wax may adhere to the surface of the electrostatic latent image carrier, so that an electrostatic latent image may not be accurately formed.
Also, because wax is less transparent than the binder resin,
In some cases, the transparency of an image such as an OHP image is reduced, resulting in a darkened projected image.

On the other hand, the smaller the exposed area ratio of the wax on the surface of the toner particles, the less the above-mentioned problem occurs. Therefore, there is no lower limit. The exposed area ratio of the wax on the surface of the toner particles refers to the area ratio (%) of the exposed wax to the total surface area of the toner particles, and can be measured using an X-ray photoelectron spectroscopy (XPS). it can. In XPS, first, the spectra of the materials constituting the toner particles, that is, the binder resin, the colorant, and the wax, are measured, and the spectra of the toner particles are fitted with the spectra of the respective materials. The area ratio of exposure to the particle surface can be determined. Using the value of the wax at this time, the exposed area ratio of the wax can be obtained.

In the particle size distribution of the toner particles, the ratio of 4 μ or less is 20% by number or less. In the first invention,
Further, in the particle size distribution of the toner particles, the ratio of 4 μm or less is 20% or less, and more preferably 18% or less. If the ratio of 4 μm or less is larger than 20%, in other words, if the fine powder component in the toner particles is too large, the toner of the fine powder component that is applied to the concave portions on the surface of the developer carrier fuses and the surface of the developer carrier is fused. Is contaminated with toner, and as a result, image density unevenness is likely to occur.

According to the first aspect of the present invention, by combining the above-mentioned constitutions, contamination of the surface of the developer carrier is prevented while securing sufficient fixing latitude, and stable developer conveyance over a long period of time becomes possible. As a result, a stable image having no image density unevenness, excellent image quality and fixability, and a stable image can be obtained.

In other words, even if the fine powder is merely small in the particle size of the toner particles (4% or less in particle size distribution is 20% or less), the exposed area ratio of the wax on the toner particle surface is large (more than 50%). In addition, the surface of the developer carrying member is contaminated with toner, and even if the exposed area ratio of the wax on the toner surface is small (50% or less), fine particles are large in the toner particle size (4 μm or less in particle size distribution is 20%). %
In this case, the surface of the developer carrying member is contaminated with toner. When the surface of the developer carrier is contaminated with toner in this way, it is difficult to uniformly hold the toner on the surface of the developer carrier, and the amount of toner transport becomes unstable, resulting in uneven image density. Is more likely to occur.

3. Configuration Specific to the Second Present Invention In the second present invention, in addition to the above-mentioned configuration common to the present invention, the toner has a number average particle diameter of 20 nm or more and 100 nm or less.
The following fine particles and abrasive particles are included as external additives.

[Fine Particles] The fine particles added to the surface of the toner particles have a volume average particle diameter of 20 nm to 100 nm.
It is essential that the thickness be equal to or less than 20 nm, and preferably 20 nm to 80 nm. If it is less than 20 nm, sufficient transferability cannot be imparted to the toner, and if it is more than 100 nm, the amount of addition necessary to impart sufficient transferability to the toner becomes too large, which may affect the chargeability of the toner. And the toner particles are separated from the toner particles, so that the surface of the developer carrier and the surface of the electrostatic latent image carrier become heavily contaminated.

Examples of the material of the fine particles include carbon black, silica, alumina, titania, zinc oxide, and resin powder. Examples of the resin powder include spherical particles such as PMMA, nylon, melamine, benzoguanamine, and fluorine, and irregular shaped powders such as vinylidene chloride and fatty acid metal salts. When the fine particles are not deformed by an external mechanical load, the particles are hardly deformed even in contact with the carrier on the surface of the toner particles, and transferability can be maintained. Therefore, among the above specific examples, inorganic fine particles such as hard silica and alumina are used as the material. Preferred, particularly preferred is silica. These fine particles are preferably added in an amount of 0.5 to 4% by weight, more preferably 0.5 to 3% by weight, based on the toner particles.

[Abrasive Particles] Further, abrasive particles are added to the surface of the toner particles. By adding the abrasive particles, contaminants on the developer carrier can be scraped off, and contamination of the developer carrier can be suppressed.

Specific examples of the abrasive particles include particles of strontium titanate, cerium oxide, silicon carbide, magnetite and the like, and inorganic oxides are preferred. More preferably, cerium oxide is used. These abrasive particles may be treated with a coupling agent such as a silane coupling agent or a titanium coupling agent, silicone oil or another organic compound.

The number-average particle diameter of the abrasive particles is set to 0.1.
The range is preferably from 0.4 to 5 μm, more preferably 0.3 to 5 μm.
２2 μm. If the number average particle size is less than 0.04 μm, the polishing effect is not sufficient, and if the number average particle size is more than 5 μm, the abrasion and scratches of the electrostatic latent image carrier are increased, which may undesirably cause image deterioration. Further, the abrasive particles are added so as to be preferably 0.1 to 4% by weight, more preferably 0.3 to 2% by weight, based on the toner particles.

In the second aspect of the present invention, the amount of the wax added to the toner particles is preferably 1 to 15% by weight, more preferably 1 to 10% by weight, and still more preferably 3 to 10% by weight. It is.

If the amount of the wax is less than 1% by weight, sufficient fixing latitude (the temperature range of the fixing roll in which the toner image can be fixed without offsetting the toner) cannot be obtained.
On the other hand, if the content is more than 15% by weight, the amount of wax detached and released from the toner increases, and the surface of the developer carrying member is easily contaminated. Further, the powder fluidity of the toner may be deteriorated, and free wax may adhere to the surface of the electrostatic latent image carrier, so that an electrostatic latent image may not be accurately formed.
Also, because wax is less transparent than the binder resin,
In some cases, the transparency of an image such as an OHP image is reduced, resulting in a darkened projected image.

In the second aspect of the present invention, the toner (including the external additive) preferably has a melt viscosity of 10 ² to 10 ⁶ poise at any temperature in the range of 80 to 120 ° C. , 10 ⁶ poise at 80 ° C. or less, and preferably 120 ° C. 10 ² poises or more at the time of. If the melt viscosity is higher than 10 ⁶ poise at any temperature in the range of 80 to 120 ° C., even when applied to the second aspect of the present invention, the power consumption during fixing increases, which is not preferable. On the other hand, if the temperature is lower than 10 ² poise at 120 ° C., the spread of the toner in the horizontal direction on the surface of the transfer material at the time of fixing becomes strong, for example, the image becomes a blurred fine line, or the transfer material is In the case of the type in which the toner penetrates, there may be a defect that the toner is soaked too much and the color development becomes poor.

In the second embodiment of the present invention, the term "melt viscosity of toner" refers to the melt viscosity measured by a hot elevated flow tester, and is specifically measured by the following method.

As a measuring apparatus, a hot elevated flow tester (Shimadzu flow tester) was used. A load of 10 kgf was applied to the sample molded by pressure with a plunger at a constant temperature, and a nozzle having a diameter of 1 mm and a length of 1 mm was applied. The extruder was extruded, and the descending amount of the plunger of the flow tester was measured according to the extruded amount. The outflow velocity was measured at each temperature, and the apparent viscosity was determined by the following equation (2).

Η ′ = TW ′ / DW ′ = πPR ² / 8LQ (2) where TW ′ = PR / 2L (2-2) DW ′ = 2Q / πR ³ (2) -3) η ': Apparent viscosity (Poise) TW': Apparent shear stress (dyne / cm ² ) of pipe wall DW ': Apparent shear rate (sec ^-1 ) of pipe wall Q: Outflow velocity (cm ³⁾ / Sec = ml / sec) P: Extrusion pressure (dyne / cm ² ) [10 kgf = 980
× 10 ⁴ dynes] R: radius of nozzle (cm) L: length of nozzle (cm)

4. Overall Configuration Common to First and Second Inventions Both the first and second inventions have at least a latent image forming an electrostatic latent image on the surface of the electrostatic latent image carrier. An image forming step, a developer carrying step of carrying a developer on the surface of the developer carrier and carrying the developer to a developing area, and the developer carried on the surface of the developer carrier in the developing area, the electrostatic latent image carrier And a developing step of developing the electrostatic latent image on the surface.

In the latent image forming step, an electrostatic latent image is formed on the surface of the electrostatic latent image carrier by a general method applied in electrophotography and electrostatic recording. That is, a laser optical system or an LE
An electrostatic latent image is formed by a D array or the like.

In the developer transport step, a developer layer composed of a toner and a carrier is formed on the surface of the developer carrier which is arranged opposite to the electrostatic latent image carrier (the developer is carried). It is transported to the development area. At this time, in order to form an appropriate and uniform developer layer on the developer carrying member, it is desirable to dispose a developer layer regulating member facing the developer carrying member. Generally, by disposing the developer layer regulating member, the toner adheres so as to be rubbed against the surface of the developer carrier by a mechanical load, and contamination is seen on the surface of the developer carrier. In the second aspect of the present invention, by appropriately controlling the surface state of the developer carrier, the amount of wax exposure of the toner particles, the particle size distribution of the toner particles, and the like, the surface state of the developer carrier is appropriately controlled and the toner By adding an appropriate external additive to the toner, contamination of the surface of the developer carrying member can be suppressed, and high transportability can be secured. Therefore, according to the present invention, even when the developer layer regulating member is provided, there is no such a problem as described above, a uniform developer layer is formed on the surface of the developer carrier for a long time, and the developer is stably formed. Thus, a high-quality image without image density unevenness can be stably obtained.

In the developing step, the electrostatic latent image is held by supplying electrostatically the charged toner in the developer layer by the developer carried on the surface of the developer carrier in the developing area. Develop the electrostatic latent image on the body surface.

The developed image is generally transferred from the electrostatic latent image carrier to a transfer material such as paper in a transfer step. Further, the transferred image is fixed to a transfer material by a fixing roll or the like in a fixing step.

When a fixing roll is used in the fixing step, the surface of the fixing roll should be
It is preferable that the toner is formed of a material having excellent releasability from the toner, such as silicone rubber or a fluororesin. At this time, it is effective that no releasing liquid such as silicone oil is supplied to the surface of the fixing roll, or that the amount of releasing liquid is as small as possible. The releasable liquid is effective for fixing latitude, but it transfers to the material to be fixed, so it has stickiness, it can not be taped, it can not be written with Magic (registered trademark) There are problems such as. This is remarkable for OHP. In addition, since the release liquid cannot make the surface of the fixing surface smooth, it also causes a decrease in OHP transparency.

According to the structure of the present invention, sufficient fixing latitude is exhibited. Therefore, when the releasing liquid is supplied to the surface of the fixing roll, the amount may be small.
It may be 1 μl or less per sheet. With such a supply amount, the above-mentioned problems can be substantially avoided.

After the toner image on the surface is transferred, the electrostatic latent image remaining on the surface of the electrostatic latent image carrier is removed by a predetermined static elimination means, and the electrostatic latent image carrier is further cleaned by a cleaning means.
Residual toner is removed. Then, the surface of the electrostatic latent image carrier is uniformly charged by the charging means in order to be subjected to the latent image forming step again.

[0084]

EXAMPLES Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In addition,
Unless otherwise specified, all “parts” in the text indicate “parts by weight”.

First, the physical properties of the wax used in Examples and Comparative Examples are shown in Table 1 below.

[0086]

[Table 1]

A: First Example of the Present Invention <Examples 1 to 3 and Comparative Examples 1 to 7> The physical properties of the petroleum resins used in the first examples and comparative examples of the present invention are shown in Table 2 below. Shown in

[0088]

[Table 2]

[Production of Toner Particles] (Toner Particles 1-1) Linear Polyester (Linear polyester selected from terephthalic acid / bisphenol A / ethylene oxide adduct / bisphenol A / propylene oxide adduct / cyclohexanedimethanol) Polyester: Tg = 60 ° C., Mn = 3,600, Mw = 33,000, acid value = 10, hydroxyl value = 19) 80 parts ・ Magenta pigment (CI Pigment Red 57) 5 parts ・ Petroleum Resin A 10 parts ・ Wax 1-A 5 parts

The above mixture is kneaded with an extruder,
After pulverizing with a pulverizer of a surface pulverizing method, fine particles and coarse particles were classified by an air classifier to obtain magenta toner particles 1-1 having a number average particle diameter d ₅₀ = 6.5 μm. The toner particles 1-1
Was 23% by number and the wax exposed area ratio on the surface was 18%.

(Toner Particles 1-2) In the toner particles 1-1, except that the wax 1-A was replaced by the wax 1-B and the petroleum resin A was replaced by the petroleum resin B,
In the same manner as -1, magenta toner particles 1-2 having a number average particle diameter d ₅₀ = 7.5 μm were obtained. The toner particles 1-
The ratio of 2 of 4 μm or less was 10% by number, and the exposed area ratio of the wax on the surface was 32%.

(Toner Particles 1-3) Toner particles 1-1 are the same as toner particles 1-1 except that the kneading conditions and the classification conditions of the extruder are changed without using petroleum resin A.
In the same manner as in the above, magenta toner particles 1-3 having a number average particle diameter d ₅₀ = 6.5 μm were obtained. The ratio of the toner particles 1-3 of 4 μm or less was 29 number%, and the exposed area ratio of the wax on the surface was 56%.

(Toner Particles 1-4) In the same manner as the toner particles 1-1, except that the petroleum resin A was not used and the amount of the wax 1-A added was 15 parts. Thus, magenta toner particles 1-4 having a number average particle diameter d ₅₀ = 6.5 μm were obtained. The ratio of the toner particles 1-4 of 4 μm or less is 18% by number, and the surface area of the exposed wax is 5%.
2%.

(Toner particles 1-5) Linear polyester (linear polyester obtained from terephthalic acid / bisphenol A / ethylene oxide adduct / bisphenol A / propylene oxide adduct / cyclohexanedimethanol: Tg = 70 ° C.) , Mn = 4,600, Mw = 38,000, acid value = 11, hydroxyl value = 23) 82 parts ・ Cyan pigment (Β-type phthalocyanine: CI pigment blue 15: 3) 5 parts ・ Petroleum 5 parts of resin C ・ 8 parts of wax 1-C

After the above mixture was preliminarily mixed, the mixture was kneaded with an extruder and pulverized with a jet mill. The particles were classified by an air classifier to obtain cyan toner particles 1-5 having a number average particle diameter d ₅₀ = 7.8 μm. The ratio of the toner particles 1-5 of 4 μm or less was 15% by number, and the exposed area ratio of the wax on the surface was 34%.

(Toner Particle 1-6) A magenta toner particle having a number average particle diameter d ₅₀ = 7.4 μm was obtained in the same manner as the toner particle 1-5, except that the classification conditions were changed. 1-6 was obtained. The toner particles 1-6-4
The ratio of μm or less was 28 number%, and the exposed area ratio of the wax on the surface was 37%.

(Toner Particles 1-7) The toner particles 1-5 were prepared in the same manner as the toner particles 1-5 except that the petroleum resin C was not used and the kneading conditions of the extruder were changed. Thus, magenta toner particles 1-7 having d ₅₀ = 7.8 μm were obtained. The ratio of the toner particles 1-7 of 4 μm or less is 15% by number, and the wax exposed area ratio of the surface is 55%.
%Met.

(Toner Particles 1-8) Magenta toner particles having a number average particle diameter d ₅₀ = 4.5 μm in the same manner as the toner particles 1-1, except that the classification conditions were changed. 1-8 was obtained. The toner particles 1-8-4
The ratio of μm or less was 38 number%, and the exposed area ratio of the wax on the surface was 23%.

[Preparation of Developer] Toner particles 1 obtained
To 100 parts of each of Nos. 1 to 1-8, 1.0 part of negatively chargeable silica having a number average particle diameter of 40 nm and 0.5 part of negatively chargeable titania having a number average particle diameter of 40 nm were added. 1 to 1-8. Further, 100 parts of a carrier in which ferrite having a particle diameter of 50 μm was coated with 0.5 μm of a styrene-methyl methacrylate copolymer was added to 6 parts of each of the obtained toners, and mixed to obtain eight kinds of developers.

[Production of Blast Sleeve (Developer Carrier)] (Blast Sleeve 1-1) Commercially available electrophotographic copying machine (A
-Developing sleeve (material: SUS, diameter 3) used in a developing machine of Color 635 (manufactured by Fuji Xerox Co., Ltd.)
(0 mm) was sandblasted with spherical glass beads using a pneumatic blaster (manufactured by Fuji Seisakusho) to produce a blast sleeve 1-1 with Rz = 4.0 μm and Sm = 55 μm. (200> Rz × 20 = 80
> Sm = 55)

(Blast Sleeve 1-2) The blast sleeve 1-1 was changed except that the conditions for the sand blast treatment were changed.
A blast sleeve 1-2 having Rz = 5.3 μm and Sm = 100 μm was produced in the same manner as in the above. (200> Rz ×
20 = 106> Sm = 100)

(Blast Sleeve 1-3) Rz was obtained in the same manner as in the blast sleeve 1-1 except that the spherical glass beads used for the sandblasting treatment were replaced with alumina particles.
= 11.8 µm, Sm = 180 µm blast sleeve 1-3 was produced. (Rz × 20 = 236>200> S
m = 180)

[Image Output Durability Test] An image output durability test was performed using the obtained developer (toner) and blast sleeve in combinations shown in Table 3 below. Specifically, using an electrophotographic copying machine (A-Color 635, manufactured by Fuji Xerox Co., Ltd.), the developing sleeves were replaced with the blast sleeves shown in Table 3 below, and the corresponding developing agents were charged, and 20,000 was added. A copy test was performed on each sheet, and each evaluation shown below was performed.

(Image Density Uniformity) After performing a copy test of 20,000 sheets, the following evaluation was continuously performed. A4
A solid unfixed toner image having a length of 10 cm and a width of 15 cm was prepared on the transfer paper so that the toner amount was 0.6 to 0.8 mg / cm ² . Next, the A-Color 635 is set so that the fixing roll temperature can be freely set and monitored.
Using a modified version of the above, the supply of release agent oil to the fixing roll was stopped, and a fixing test was performed in a state where the release agent oil was not substantially present on the surface of the fixing roll (surface temperature of the fixing roll: 155 ° C.). With respect to the obtained fixed image, the image portion 5
The density at each location was measured with a spectrophotometer (X-Rite), and the density difference between the highest density part and the lowest density part was used as an evaluation index of image density uniformity. The results are summarized in Table 3 below.

(Contamination of Developing Sleeve) Regarding toner contamination on the developing sleeve (blast sleeve),
After the zero-copy test, the developing sleeve is blown off with compressed air, and the density of the developing sleeve surface is measured at three points using a spectrophotometer (X-Rite). After the measurement, the average density difference Δ between the two was obtained, and this was used as an evaluation index for developing sleeve contamination. The results are summarized in Table 3 below.

[0106]

[Table 3]

As is clear from the results in Table 3, the first
In the case of the combination of the developer and the developing sleeve of Examples 1 to 3 of the present invention, toner contamination on the surface of the developing sleeve was small, and image density unevenness was also small. No density unevenness was observed. On the other hand, in Comparative Examples 1 to 7, toner contamination on the surface of the developing sleeve occurred, and the developer layer on the developing sleeve became uneven, and density unevenness was observed in the solid image of the copy. . Then, image density unevenness due to the occurrence of density unevenness was observed, and it became clear that the image quality deteriorated.

B: Second Embodiment of the Present Invention <Examples 4 to 7, and Comparative Examples 8 to 10>

(Toner particles 2-1) Linear polyester (Linear polyester obtained from terephthalic acid / bisphenol A / ethylene oxide adduct / cyclohexanedimethanol: Tg = 62 ° C., Mn = 4,000, Mw) = 35,000, acid value = 12, hydroxyl value = 25) 92 parts-Magenta pigment (CI Pigment Red 57) 3 parts-Wax 1-A 5 parts

The above mixture is kneaded with an extruder,
After pulverizing with a pulverizer of a surface pulverizing method, fine particles and coarse particles were classified by an air classifier to obtain magenta toner particles 2-1 having a number average particle diameter d ₅₀ = 6.7 μm. The toner particles 2-1
Was 16% by number and the wax exposed area ratio on the surface was 41%.

(Toner Particle 2-2) The number average particle diameter d ₅₀ of the toner particle 2-1 was changed in the same manner as the toner particle 2-1 except that the wax 1-A was replaced with the wax 1-D.
= 7.8 μm magenta toner particles 2-2 were obtained. The ratio of the toner particles 2-2 of 4 μm or less is 24% by number,
The exposed area ratio of the wax on the surface was 58%.

(Toner Particles 2-3) The number average particle diameter d ₅₀ of the toner particles 2-1 was changed in the same manner as the toner particles 2-1 except that the wax 1-A was replaced with the wax 1-C.
= 7.6 μm of magenta toner particles 2-3 were obtained. The ratio of the toner particles 2-3 having a particle size of 4 μm or less was 19% by number, and the exposed area ratio of the wax on the surface was 38%.

(Toner particles 2-4) Linear polyester (linear polyester selected from terephthalic acid / bisphenol A / ethylene oxide adduct / bisphenol A / propylene oxide adduct / cyclohexanedimethanol: Tg = 70 ° C.) , Mn = 4,600, Mw = 38,000, acid value = 11, hydroxyl value = 23) 92 parts ・ Cyan pigment (Β-type phthalocyanine: CI Pigment Blue 15: 3) 3 parts ・ Wax 1-A 5 parts

After premixing the above mixture, the mixture was kneaded with an extruder and pulverized with a jet mill. The particles were classified by an air classifier to obtain cyan toner particles 2-4 having a number average particle diameter d ₅₀ = 7.1 μm. 4 μm of the toner particles 2-4
The following ratio was 11% by number, and the wax exposed area ratio on the surface was 42%.

[Preparation of developer] Toner particles 2 obtained
For each 100 parts of each of Nos. 1 to 2-4, 1.0 part of negatively chargeable silica having a number average particle diameter of 40 nm and a number average particle diameter of 40 parts
Toner 2-1 to 2-4 were obtained by adding 0.5 part of negatively chargeable titania having a particle diameter of 0.4 nm and 0.4 part of cerium oxide (number average particle diameter: 0.8 μm) as abrasive particles. Further, in the preparation of the toner 2-1, the toner prepared without adding only cerium oxide was referred to as a toner 2-5. Table 4 below summarizes the results of measuring the melt viscosities of the obtained toners 2-1 to 2-5 by the above-described method using a thermal elevated flow tester.

Further, 100 parts of a carrier obtained by coating a ferrite having a particle diameter of 50 μm with 0.2 μm of a styrene-methyl methacrylate copolymer was added to 6 parts of each of the obtained toners, and mixed to obtain five types of developers. Was.

[Production of Blast Sleeve (Developer Carrier)] (Blast Sleeve 2-1) Commercially available electrophotographic copying machine (A
-Developing sleeve (material: SUS, diameter 3) used in a developing machine of Color 635 (manufactured by Fuji Xerox Co., Ltd.)
(0 mm) was sandblasted with alumina particles using a pneumatic blaster (manufactured by Fuji Seisakusho) to produce a blast sleeve 2-1 with Rz = 4.9 μm and Sm = 61 μm. (200> Rz × 20 = 98>
Sm = 61)

(Blast Sleeve 2-2) The blast sleeve 2-1 was changed except that the conditions for the sandblasting were changed.
A blast sleeve 2-2 with Rz = 2.8 μm and Sm = 43 μm was produced in the same manner as in Example 1. (200> Rz × 2
0 = 56> Sm = 43)

(Blast Sleeve 2-3) The blast sleeve 2-1 was changed except that the conditions of the sand blast treatment were changed.
A blast sleeve 2-3 having Rz = 2.0 μm and Sm = 45 μm was produced in the same manner as in Example 1. (200> Sm = 4
5> Rz × 20 = 40)

(Blast Sleeve 2-4) The blast sleeve 2-1 was changed except that the conditions for the sand blast treatment were changed.
Rz = 10.8 μm, Sm = 110 μm
A blast sleeve 2-4 was produced. (Rz × 20 =
216>200> Sm = 110)

[Image Endurance Test] An image endurance test was carried out using the obtained developer (toner) and blast sleeve in combinations shown in Table 4 below. Specifically, using an electrophotographic copying machine (A-Color 635, manufactured by Fuji Xerox Co., Ltd.), the developing sleeves were replaced with the blast sleeves shown in Table 4 below, and the corresponding developing agents were charged, and 20,000 was added. A copy test was performed on each sheet, and each evaluation shown below was performed.

(Offset Resistance) After performing a copy test of 20,000 sheets, the following evaluation was continuously performed. A4
A solid unfixed toner image having a length of 10 cm and a width of 15 cm was prepared on the transfer paper so that the toner amount was 0.6 to 0.8 mg / cm ² . Next, the A-Color 635 is set so that the fixing roll temperature can be freely set and monitored.
Using a modified version of the above, the supply of release agent oil to the fixing roll was stopped, and a fixing test was performed in a state where the release agent oil was not substantially present on the surface of the fixing roll. In the fixing test, the unfixed toner image was fixed by using a transfer sheet holding the toner image at each surface temperature while gradually changing the surface temperature of the fixing roll. At this time, observation was made as to whether or not toner fouling from the fixing roll occurred in the margin of the paper, and a temperature area where no fouling occurred was defined as a non-offset temperature area, and this was used as an index for evaluating anti-offset properties. The results are summarized in Table 4 below.

(Contamination of Developing Sleeve) Contamination of the developing sleeve was evaluated by the method and the evaluation index described in the above “A: First Embodiment of the Present Invention”. The results are summarized in Table 4 below.

[0124]

[Table 4]

As is clear from the results in Table 4 above, the second
In the case of the combination of the developer and the developing sleeve of Examples 1 to 4 of the present invention, the toner contamination on the surface of the developing sleeve was small, and there was no problem in the obtained image.

Further, the fixing property of the toner in the developers of Examples 1 to 4 is good, and even if the release roller oil is not used for the fixing roll, the toner spreads from a low temperature to a high temperature in a non-offset temperature region. And showed a wide latitude.

On the other hand, in Comparative Examples 1 and 3, toner contamination on the surface of the developing sleeve occurred, and the developer layer on the developing sleeve became uneven, so that density unevenness was observed in the solid image of the copy. Became. In Comparative Example 2, although the toner contamination on the surface of the developing sleeve was small, a part of the developing sleeve was abraded differently from other parts, and the transport amount of the developer was increased in that part. The density was light and dark.

[0128]

According to the present invention, it is possible to provide an image forming method capable of stably transporting a developer for a long period of time, free from image density unevenness, excellent in image quality and fixability, and capable of obtaining a stable image. it can.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiro Oya 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Kaori 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Koichi Hamano 1600 Takematsu, Minami Ashigara, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Kotaro Yoshihara 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. Address F-term in Fuji Xerox Co., Ltd. (reference) 2H005 AA06 AA08 CA14 CB07 CB13 EA05 EA07 EA10 2H077 AD02 AD06 EA03 FA03 FA13 FA22 GA13

Claims (2)

[Claims] At least a latent image forming step of forming an electrostatic latent image on the surface of an electrostatic latent image carrier, and a developer transporting step of carrying a developer on the surface of the developer carrier and transporting the developer to a developing area;
A developing step of developing an electrostatic latent image on the surface of the electrostatic latent image carrier with the developer carried on the surface of the developer carrier in the development region, wherein the developer is at least A toner comprising toner particles, wherein the toner particles contain at least 1 to 15% by weight of wax, and the exposed area ratio of the wax on the surface of the toner particles is 50% or less; , The ratio of 4 μ or less is 20
% Or less, and the surface of the developer carrying member satisfies the relationship of the following formula (1). 200 ≧ Rz × 20 ≧ Sm (1) In the above formula (1), Rz represents a ten-point average roughness (μm) of the surface of the developer carrying member, and Sm is an average of irregularities on the surface of the developer carrying member. Indicates the interval (μm). 2. At least a latent image forming step of forming an electrostatic latent image on the surface of the electrostatic latent image carrier, and a developer transporting step of carrying the developer on the surface of the developer carrier and transporting the developer to a developing area;
A developing step of developing an electrostatic latent image on the surface of the electrostatic latent image carrier with a developer carried on the surface of the developer carrier in a development area, wherein the developer is a toner. Wherein the toner is composed of toner particles containing at least wax, fine particles having a number average particle diameter of 20 nm or more and 100 nm or less, and abrasive particles, wherein the surface of the developer carrying member has the following formula (1) An image forming method characterized by satisfying the following relationship: 200 ≧ Rz × 20 ≧ Sm (1) In the above formula (1), Rz represents a ten-point average roughness (μm) of the surface of the developer carrying member, and Sm is an average of irregularities on the surface of the developer carrying member. Indicates the interval (μm).