JP2001272821A - Method for manufacturing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing toner which does not cause irregular printing, background fog or fluctuation in electrification during continuous printing. SOLUTION: The method relates to the manufacture of toner containing toner particles having 4 to 15 μm volume average particle size and an external additive including polymer fine particles having 0.1 to 1 μm particle size obtained from at least one kind selected from acrylic monomers, methacrylic monomers and styrene monomers. The toner particles and the polymer fine particles are separately prepared from monomers in water by a polymerization method, and then uniformly mixed in water in one vessel and dried to directly externally add the polymer fine particles to the toner particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner. The toner obtained by the method of the present invention can be used in an electrophotographic copying machine, an electrophotographic printer, an electrostatic recording device, and the like.

[0002]

2. Description of the Related Art U.S. Pat.
The method described in US Pat. No. 691, for example, is well known, but generally employs a photoconductive insulator (such as a photo-condrum), and forms a uniform electrostatic charge on the photoconductive insulator by corona discharge or the like. To form an electrostatic latent image by irradiating a light image on the photoconductive insulator by various means, and then visualize the latent image with development using a fine powder called a toner, if necessary. After transferring the toner image onto paper or the like, the toner image is melted by pressurization, heating, solvent vapor, light, or the like, and fixed on paper or the like to obtain a printed matter. As a toner for developing these electrostatic latent images, a toner obtained by dispersing a colorant such as a dye or carbon black in a binder resin made of a natural or synthetic polymer substance is finely pulverized to about 1 to 30 μm. Particles are used.

Conventionally, in an electrophotographic copying machine or an electrophotographic printer, generally, an electrostatic image is formed by exposing a uniformly charged photoreceptor surface in accordance with image information for forming light with a laser or the like using a laser or the like. Then, the charged toner conveyed to the contact portion with the photoreceptor by the toner carrier is adhered by an electric force, and the electrostatic image is visualized, that is, developed. Then, after a visible image of the toner is transferred onto recording paper by an electric force, the toner is fixed by heat, pressure, light, or the like, thereby obtaining a copy or a print. In such an image forming method,
Conventionally, in a non-magnetic one-component developing machine, a layer thickness regulating member as shown in FIG. 1 has been used to regulate the amount of toner adhered to a toner carrier, and a styrene-acryl resin or a polyester resin is used as a toner binder. Was used. The layer thickness regulating member uses a conductive metal blade and provides a potential difference between the layer and the toner carrier. That is, in the case of using a negatively chargeable toner, the toner carrier has a -100
−500V, and 50% from the toner carrier to the layer thickness regulating member.
A bias of ~ 200V lower is applied. As a result, when the negatively chargeable toner on the toner carrier passes through the layer thickness regulating member, it is usually frictionally charged and receives a negative charge injection from the layer thickness regulating member. As described above, the amount of charge of the toner is stabilized from high temperature and high humidity to low temperature and low humidity by frictional charging and charge injection.

In addition, when the toner is charged by the layer thickness regulating member, the toner is strongly rubbed by the layer thickness regulating member and the toner carrier. For this reason, if a low-strength material is contained in the toner, the material is fused to the layer thickness regulating member and the toner carrier due to pressure. When a foreign matter is fused to the layer thickness regulating member and the toner carrier, the toner layer thickness becomes non-uniform, and the toner causes poor charging, so that white streaks or black streaks are generated on the paper.

Further, in the related art, in an electrophotographic copying machine, an electrophotographic printer, or the like, when a toner image on a photoreceptor is transferred onto a recording sheet, a corona transfer method in which corona discharge is performed from the back side of the recording sheet is widely used. ing. However, in the corona transfer method, a high voltage of several kilovolts is required for corona discharge, which leads to an increase in the cost of the apparatus, and the ozone generated by the discharge damages the components of the apparatus, and particularly, the life of the photoconductor. There was a problem of shortening. Further, there is a problem that ozone causes discomfort to a user of the apparatus, and that if the concentration is high, it is harmful to the human body. In order to solve this problem, there is an image forming method in which transfer is performed by bringing a transfer roller into close contact with the back surface of a recording sheet. Such an image forming method transfers a toner image by bringing a conductive transfer roller to which a constant voltage is applied from the back side of the recording paper, and applies a voltage of several hundred V to 2.0 kV to the transfer roller. Can be transferred. In this scheme,
There is almost no problem of ozone generation, and the adhesion between the photosensitive member and the recording paper is good, so that toner scattering and image disturbance are small. In such an image forming method, a transfer roller to be used and a photoconductor are disposed in pressure contact, a transfer medium such as paper or OHP is passed between them, and a bias is applied between the transfer roller and the photoconductor to remove toner. The image is formed by transferring the image to paper. However, in this image forming method, since the toner image on the photoreceptor is transferred onto paper by applying pressure, the center portion of the line image is compressed, so that the hollow portion of the character is generated (FIG. 6). The hollowing of this character was particularly noticeable in OHP.

Japanese Patent Application Laid-Open No. Sho 56-64352 discloses that toner particles are mixed (externally added) with fine particles charged to the opposite polarity to the toner particles in order to improve the charging characteristics and cleaning characteristics of the toner. JP-A-54-45133, JP-A-60-188681, JP-A-60-186852, JP-A-60-18
It is known in 6854 and others. When polymer fine particles are externally added as fine particles having a polarity opposite to that of the toner particles, the dried powder toner and polymer fine particles are externally added using a Henschel mixer or a super mixer. However, when polymer particles produced by emulsion polymerization or soap-free emulsion polymerization are dried, the particle size is small,
The particles strongly agglomerate. For this reason, the toner and the polymer fine particles are dry-mixed as described above, and the aggregation of the polymer fine particles does not melt as expected even if the polymer fine particles are externally added to the surface of the toner, and as a result, the polymer fine particles are externally added. Not only does the fluidity of the toner deteriorate, but also because of the non-uniform mixing of the toner and the polymer particles, the polymer particles are easily removed from the toner, and the polymer particles sometimes contaminate the photoreceptor. That is, since the polymer fine particles have a spherical shape, they pass through the photosensitive member cleaning blade, form a film on the photosensitive member, and cause print unevenness and background fog. Apart from this, the charge amount distribution is widened due to uneven mixing of the toner and the polymer fine particles, causing fogging and charge fluctuation during continuous printing.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a toner which does not cause unevenness in printing, fogging of a background portion, or charge fluctuation during continuous printing.

[0008]

In order to solve the above-mentioned problems, the present invention provides toner particles having a volume average particle size of 4 to 15 μm and at least one selected from acrylic monomers, methacrylic monomers, and styrene monomers. And an external additive containing polymer fine particles having a particle size of 0.1 to 1 μm, the method comprising:
The toner particles and the polymer fine particles are separately formed by a polymerization method from a monomer in water, then uniformly mixed in water in the same container, and then dried to directly add the polymer fine particles to the toner particles. It is characterized by doing.

[0009]

According to the present invention, it has been found that by employing the above-described structure, a toner which does not cause fogging in the background portion at high temperature and high humidity and can maintain good print quality for a long period of time can be obtained. Was done. This is considered for the following reason. That is, at normal temperature and normal humidity,
In the toner, charge injection from the film thickness regulating member is dominant, and reverse charge injection from the developer carrier hardly occurs. However, high temperature and high humidity conditions (for example, 40 ° C., 8
At 0% RH), the inherently insulative toner has low resistance and is more susceptible to reverse charge injection from the developer carrier as well as charge injection from the layer thickness regulating member. Further, even in the case of a non-magnetic insulating toner manufactured to have one of the positive and negative polarities, there are variations in its characteristics due to manufacturing conditions and the like. Therefore, for example, when the toner to be used is a toner to be charged to a negative polarity, in a high temperature and high humidity state,
Positively charged toner is generated in combination with negatively charged toner. The positively charged toner appears as a fog on the background of the electrostatic latent image formed on the image carrier. Therefore, in the present invention, as a means for preventing the reverse charging of the toner, fine particles charged to a polarity opposite to the charging polarity of the toner are used for the non-magnetic insulating toner charged to one of the positive and negative polarities. Is added externally. By externally adding the oppositely charged fine particles, only a very small part of the surface of the non-magnetic insulating toner appears to have positive charging properties. Therefore, the toner
Substantially, the positive charge appears to have a high resistance to the positive charge, so that the positive charge from the developing carrier is hardly injected, and it is considered that the oppositely charged toner can be prevented. Since no reversely charged toner is generated, it is possible to suppress the fogging of the background portion. By the way, in order to prevent reverse charging of the non-magnetic insulative toner of negative charge, as the resin fine particles charged to positive polarity, a radically polymerizable monomer containing 90 parts by weight or more of styrene monomer is used by using an azo initiator. Resin fine particles prepared in this manner can be used.

When the amount of the resin fine particles is 0.05 parts by weight or less with respect to the toner, the effect is small. On the other hand, if it exceeds 0.75 parts by weight, there is no fogging of the toner background, but finely charged resin fine particles are developed on the printing background of the latent image carrier (photoreceptor), and it adheres strongly to the latent image carrier. I do. The strongly adhered resin particles hinder the formation of the latent image on the latent image carrier, and are also caught between the latent image carrier and the cleaning blade, causing the latent image carrier to be scraped during continuous printing, resulting in a latent image. An obstacle such as a decrease in the surface potential of the carrier occurs. For this reason, the external addition amount of the resin fine particles is
0.05 to 0.75 parts by weight shows good characteristics, but more preferably 0.2 to 0.6 parts by weight. The particle size of the resin fine particles is preferably 0.1 to 1 μm. Fine particles of 0.1 μm or less are extremely troublesome to manufacture, expensive, and 1 μm
Larger particles will separate from toner particles,
Good effect cannot be obtained.

Here, as the monomer copolymerizable with the styrene monomer for producing the resin fine particles, there are acrylic or methacrylic monomers such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, and the like.
Α- such as n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc.
Methylene fatty acid monocarboxylic acid esters, methyl acrylate, ethyl acrylate, n-butyl acrylate,
There are acrylates such as isobutyl acrylate. These can be used alone or as a mixture.

The reason why styrene monomer is contained in the resin fine particles in an amount of 90 parts by weight or more is as follows. That is, since styrene has a benzene ring, it becomes strong when polymerized from acrylic or methacrylic monomers. At the time of continuous printing, in the non-magnetic one-component system, charging is performed by strongly rubbing the toner with a layer thickness regulating member. At this time,
When the amount of the acrylic or methacrylic material is more than 10 parts by weight, the produced resin fine particles are crushed between the layer thickness regulating member and the toner, and are fused to the layer thickness regulating member. If this continues,
The toner layer of the toner carrier becomes non-uniform, and uneven printing such as black streaks and white streaks occurs. Therefore, the styrene monomer needs to be contained in an amount of 90 parts by weight or more based on the total amount of the monomers.
Incidentally, since this toner is strong, when it is used in an electrophotographic image forming apparatus using a transfer roller, the potential of the photoreceptor is quickly reduced when the transfer roller and the photoreceptor are rubbed. To cope with this, the pressing force of the transfer roller is set to 170
g / cm ² . In this case, the potential reduction time of the photoconductor could be after printing of 1 to 35 sheets.

As azo initiators, 2,2'-azobis (2-amidinopropane) hydrochloride,
2'-azobis [2- (5-methyl-2-imidazoin-2-yl) propane] dihydrochloride and the like.
As commercial products, V-50, VA-041, VA-04
4, VA-054, VA-058, VA-059, VA
Water-soluble azo-based initiators such as -060, VA-080 and VA-086 (Wako Pure Chemical Industries) can be used. Also, well-known water-soluble initiators include peroxide initiators such as hydrogen peroxide and persulfate initiators such as potassium persulfate. However, since the initiator used for soap-free emulsion polymerization needs to be water-soluble, the abundance on the resin particle surface increases. Further, since the initiator is bonded to the molecular terminals of the resin particles, the initiator easily affects the charging characteristics of the resin. That is, in soap-free emulsion polymerization, resin fine particles using an azo-based initiator tend to be positively charged with a nitrogen atom in the molecule of the azo-based initiator, so that the resin fine particles made from the initiator also have a positive chargeability. Have. However, the peroxide-based and persulfate-based initiators exhibit negative chargeability because the resin surface becomes acidic. Therefore, the fine particles prepared with the peroxide-based and persulfate-based initiator are hardly charged with respect to the negatively-chargeable toner. Therefore, the type of the monomer and the selection of the initiator used when preparing the resin fine particles are the most important. In order to obtain the resin fine particles having the positive charge property with respect to the negatively chargeable toner, the styrene monomer is 90 parts by weight or more. It is necessary to carry out a soap-free emulsion polymerization of the contained radical-polymerizable monomer using an azo-based initiator. For the above reasons,
By externally adding the resin fine particles to the negatively charged toner, the background fog at high temperature and high humidity was improved.

Further, these toners may be used in combination with external additives such as silica, alumina and titanium oxide for the purpose of improving the fluidity and the like. According to the present invention, furthermore, it is possible to satisfactorily suppress the hollowing of characters when transferring the toner image from the back surface of the recording paper with the transfer roller in close contact.

In this case, if the amount of the resin fine particles is less than 0.05 part by weight, the effect is not sufficient. If the amount is more than 1.0 part by weight, the resin particles fall off the toner and contaminate the image carrier.

The cause of voids in characters during transfer is considered as follows. That is, the toner image on the photoreceptor is strongly compressed by the roller during transfer. The compression is higher at the center of the character, and this compression of the toner causes the high-fluidity toner to be packed tightly between the toners and adheres strongly to the photoreceptor, thereby inhibiting transfer.

In the present invention, 0.1 μm to 1 μm of the toner
Since the fine particles of μm are mixed with the toner particles, that is, externally added, the fluidity of the toner can be reduced, the toner is less likely to be compressed, and the closest packing between the toners can be prevented. Furthermore, by externally adding fine particles having the opposite charge to the toner particles to the toner particles, the mirror image force between the image carrier and the toner can be reduced, and the toner adhesion to the image carrier can be reduced. Accordingly, even when a transfer roller is used, it is possible to prevent a gap in the transfer. Incidentally, positively charged fine particles may be externally added to the negatively charged toner.

Here, as the azo-based initiator, the above-mentioned azo-based initiator can be used. Well-known water-soluble initiators include peroxides such as hydrogen peroxide and persulfate initiators such as potassium persulfate.
However, since the initiator used for emulsion polymerization needs to be water-soluble, the abundance on the resin particle surface increases. Further, since the initiator is bonded to the molecular terminals of the resin particles, the initiator easily affects the charging characteristics of the resin. That is, in the emulsion polymerization, the fine resin particles using an azo-based initiator are easily charged positively with the nitrogen atom in the molecule of the azo-based initiator, so that the fine resin particles formed from the initiator also have a positive charging property. However, peroxide-based and persulfate-based initiators exhibit negative chargeability because the resin surface becomes acidic. Therefore, the fine particles obtained with the peroxide-based and persulfate-based initiator are hardly charged with respect to the negatively charged toner. Therefore, it is extremely important to select the type of monomer and the initiator used when producing the resin fine particles.

The reason why styrene and methyl methacrylate are selected as monomers is that styrene and methyl methacrylate resins have a glass transition temperature of about 100 ° C.
Which is higher than an average acrylic or methacrylic resin. If the glass transition temperature is low, the produced resin fine particles are fused to toner and other members of a developing machine, and the function thereof is lost by continuous printing. As described above, since styrene and methyl methacrylate are selected so that the glass transition temperature is about 100 ° C. or higher, no fusion of the toner occurs in the non-magnetic one-component developing machine. In addition, the reason that styrene is set to 15 parts by weight or less based on all monomers is that the homopolymer of styrene has a benzene ring in its molecular structure, so that it becomes very hard, and the pressure of the transfer roller during continuous printing causes the resin fine particles to become fine. To hurt. In this case, the pressing force of the transfer roller against the photosensitive member was set at about 175 g / cm ² . As a result, the potential reduction period of the photosensitive member could be extended to 40,000 sheets or more.

Next, as a method for producing this toner,
(1) a method of producing a toner by a conventionally known pulverization method, (2) a method of producing a toner directly from a monomer capable of radical polymerization in water by a suspension polymerization method, and (3) an emulsion polymerization of a monomer capable of radical polymerization in water. And (4) forming seed polymer particles having a particle size of 0.1 to 2 μm with a monomer, an initiator and water, and then forming the same with a water-insoluble substance, a monomer and There is a method in which after swelling with a colorant, a monomer component is polymerized in the particles and the particle size is increased to produce the monomer. Of these, the toner may be manufactured by any method.However, in the methods (2) to (4), since the toner is manufactured in an aqueous system, the toner easily absorbs moisture in the air, and has a low temperature and high humidity. Easy to resist. Accordingly, if resin fine particles are externally added to the toners manufactured by the methods (2) to (4), the fogging margin can be greatly increased.

In the present invention, the volume average particle diameter is 4 to 15
A method for producing a toner comprising: toner particles having a particle diameter of 0.1 μm; and an external additive containing polymer fine particles having a particle diameter of 0.1 to 1 μm obtained from at least one selected from an acrylic monomer, a methacrylic monomer, and a styrene monomer. As the above, the toner particles and the polymer fine particles are separately formed in water by a polymerization method from a monomer, and then uniformly mixed in water in the same container, and then dried, so that the polymer fine particles are directly added to the toner particles. The method of external addition is used.

The dispersant used here is preferably a mixture of water and alcohol. The polymer fine particles are produced by using a radically polymerizable monomer and using a known emulsion polymerization method or a soap-free emulsion polymerization method.

A toner containing a colorant is also polymerized from a monomer which can be radically polymerized in water, and the following three methods can be used for producing such a toner. (1) Produced by suspension polymerization method. (2) It is produced by aggregating fine particles prepared by an emulsion polymerization method or a soap-free emulsion polymerization method. (3) Using the fine particles prepared by the emulsion polymerization method or the soap-free emulsion polymerization method as seed particles, swelling them with a water-insoluble substance, the monomers and the coloring agent, and then polymerizing the monomer components in the particles to form particles. Manufacture by enlarging.

Next, the polymer fine particles and the toner separately formed in this way and dispersed in water are transferred to the same container, mixed, and dried. By taking such a step, the polymer fine particles and the toner can be almost completely and uniformly dispersed.

The monomer used in the production of the polymer fine particles and the toner may be a monomer having one ethylenically unsaturated bond in one molecule. For example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p
-Chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn
-Nonylstyrene, pn-octylstyrene, pn
Styrene and derivatives thereof such as hexyl styrene and pn-dodecyl styrene, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; halogenation such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride. Vinyls. Vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, methacrylic acid -2-Ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc., α-methylene fatty acid monocarboxylic esters, methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic Acrylates such as isobutyl acid, vinyl methyl ether, vinyl ethyl ether, vinyl ethers such as vinyl isobutyl ether,
Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone, n-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, vinyl naphthalenes, acrylonitrile, methacrylic There are acrylic acid and methacrylic acid derivatives such as lonitrile and acrylamide. These can be used alone or as a mixture.

As the emulsifier used in the emulsion polymerization method, a known emulsifier, for example, a soap, a cationic activator, an anionic activator, a fluorine activator and the like can be used. Generally, the amount of these emulsifiers used is preferably from 0.01 to 1% by weight, more preferably from 0.1 to 0.5% by weight, based on water. As a suspending agent, polyvinyl alcohol or the like is used, and its use amount is preferably 0.01 to 1% by weight, more preferably 0.1 to 0.5% by weight, based on water.

As the polymerization initiator, an oil-soluble initiator is usually used in suspension polymerization, and a water-soluble initiator is used in emulsion polymerization. In the emulsion polymerization, an oil-soluble initiator may be used in combination. Further, the polymerization may be performed by heat, or may be performed by light or γ-ray. Known thermal polymerization initiators include, for example, persulfates such as potassium persulfate, azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate, and the like. It can also be used. As the photopolymerization initiator, any known initiator may be used. For example, benzoin, benzoin methyl ether, benzoin propyl ether, benzyl, benzophenone, 3,3 ′, 4,
4'-tetra- (t-butylperoxycarbonyl) benzophenone and the like can be used. Usually, the amount of these polymerization initiators used is generally about 0.01 to 1% by weight of the polymerizable mixture.
0%, especially 0.05-5% by weight is sufficient.

As the coloring agent, known pigments and dyes can be used. For example, black pigments include channel black and furnace black, and colored pigments include cadmium yellow, pyrazolone red, phthalocyanine blue B, and phthalocyanine green. Dyes include CI Direct Red 1 and CI Direct Blue 1.

By externally adding the polymer fine particles to the toner using the above-mentioned method, the polymer fine particles are uniformly dispersed on the toner surface, and a toner exhibiting excellent printing characteristics with a sharp charge distribution of the toner for a long time can be obtained. Can be.

[0030]

Examples of the present invention will be described below. However, the invention is not limited by these examples. (A) Description of Image Forming Apparatus FIG. 1 is a cross-sectional view of an image forming apparatus used in Examples and Comparative Examples, and FIG. 2 is a configuration of a process unit to which a non-magnetic one-component developer used in Examples and Comparative Examples is applied. FIG. 3 and FIG. 3 are illustrations of the image forming apparatus used in the examples and comparative examples.
A printer device is shown as an image forming apparatus. In the apparatus cross-sectional view of FIG. 1, reference numeral 2 denotes a process unit, which is provided above the paper cassette 12, and which is described later with reference to FIG. 4, and 6 denotes a heat fixing device, which is sandwiched between a heat roller 60 and a backup roller 61. This is for fixing the toner image on the sheet, and is provided with a cleaning roller 62 for removing the toner adhered to the heat roller 60. Reference numeral 7 denotes an optical unit which scans the light of a semiconductor laser driven by image information with a polygon mirror and irradiates the photosensitive drum 40 of the process unit 2 through the developing unit 5 as indicated by a dotted arrow in FIG. Reference numeral 8 denotes a paper separating unit, which has a discharge electrode and discharges a charge having a polarity opposite to the potential of the paper back surface on the back surface of the transferred paper, discharges the paper back surface, and transfers the paper to the photosensitive drum 40. Is to be separated from Reference numeral 30 denotes a pickup roller that picks up the paper in the paper cassette 12, reference numeral 31 denotes a registration roller, which conveys the leading edge of the paper picked up by the pickup roller 30, and reference numeral 32 denotes a manual feed guide. The sheet is opened to the right and guides the manual feed paper to the manual feed roller 33. Reference numeral 33 denotes a manual feed roller, which feeds the paper inserted from the manual feed guide 32 to the process unit 2.
Is to be transported. Reference numeral 34 denotes a cover shaft, which serves as a rotation shaft of the front cover 10, and reference numeral 36 denotes a discharge roller, which discharges the sheet that has passed through the heat fixing device 6 to the stacker 14.

In the configuration diagram of the process unit in FIG. 2, the process unit 2 includes a drum cartridge 4 and
The developing device 5 includes a drum cartridge 4
Are detached from the drum cartridge 4 by removing the pins.
Explaining the structure of the drum cartridge 4, reference numeral 40 denotes a photosensitive drum, which is formed by forming an organic photosensitive material layer (such as OPC) 400 on the surface of a cylindrical base 401 made of aluminum or the like, and rotated counterclockwise as shown in the figure. Reference numeral 41 denotes a charging roller, which is constituted by a conductive rotating brush charger in which conductive rayon fibers are woven into a core metal and planted, and uniformly charges the photosensitive drum 40 to about -600 V to -700 V. . Reference numeral 42 denotes a transfer roller, which is provided on the drum cartridge 4 and is made of a conductive porous rubber material, for example, a porous foamed polyurethane sponge material. The transfer roller 42 is pressed against the photosensitive drum 40, and a transfer voltage is applied thereto. Reference numeral 43 denotes a unit for transferring the toner image onto paper, reference numeral 43 denotes a waste toner box, a unit for scraping residual toner on the photosensitive drum 40 by a scraping blade 44, and accommodating the drum cartridge 45; Reference numeral 46 denotes a roller cover for holding the transfer roller 42. Next, the configuration of the developing device 5 will be described. Reference numeral 50 denotes a developing roller, which is formed of a conductive elastic roller, preferably a conductive porous rubber material, for example, a conductive porous foamed polyurethane sponge material. Is rotated clockwise as shown in FIG. 3 to hold the non-magnetic one-component toner with the holding force of the surface thereof and transport it to the photosensitive drum 40, and is pressed against the photosensitive drum 40 so as to have a predetermined nip width, In addition, a developing bias voltage of -300 V is applied via the power supply 50a. Reference numeral 51 denotes a layer thickness regulating blade, which regulates the layer thickness of the toner adhered to the developing roller 50 to a predetermined thickness, is formed of a 0.1 mm thick stainless steel plate, and is pressed against the developing roller 50, for example, A negative voltage of −400 V is applied via the power supply 51a,
At the time of regulating the toner layer thickness, a negative charge is injected into the toner, the toner is forcibly charged negatively, and the toner is stably charged even at high humidity and high temperature. A reset roller 52 is made of a conductive sponge material, is in contact with the developing roller 50, and is rotated in the same direction as the developing roller 50. The reset roller 52 scrapes toner from the developing roller 50 on the right side of FIG. A bias voltage of -400 V is applied via 52a, and acts to supply toner to the developing roller 50 on the left side of the drawing. Reference numerals 53 and 54 denote paddle rollers which rotate to stir and charge the non-magnetic one-component toner in the developing device 5 and to reset the toner.
55 is a cassette accommodating portion, which accommodates the toner cassette 56. Reference numeral 56 denotes a toner cassette which contains a one-component non-magnetic toner and is detachably set in the cassette accommodating portion 55. Reference numeral 57 denotes a toner supply lever, which is provided in the toner cassette 56, rotates, and A device for supplying the toner in the cassette 56 into the developing device 5, 58 is a handle, provided in the toner cassette 56 and used for holding the toner cassette 56 by hand, 59 is a paper guide rib, and a roller cover Along with 46, the sheet guides the sheet between the photosensitive drum 40 and the transfer roller 42.

The operation of this printer will be described with reference to FIGS. 1 to 3. The paper in the paper cassette 12 is picked up by a pickup roller 30, abutted against a registration roller 31, the leading ends thereof are aligned by the registration roller 31, and a U-shaped conveyance path is used. 3 is conveyed toward the photosensitive drum 40. On the other hand, when the sheet is picked by the registration roller 31, image exposure on the photosensitive drum 40 by the optical unit 7 is started, and the photosensitive drum 4 charged to -600V by the charging roller 41 is started.
The potential of the image exposure portion of 0 becomes zero, and an electrostatic latent image corresponding to the image is formed. In the developing device 5, the developing roller 50
Since the bias voltage of 400 V is applied, the negatively charged toner adheres to the image exposure portion of the photosensitive drum 40 where the potential is zero, and a toner image is formed. This photosensitive drum 4
The toner image of No. 0 is transferred to the sheet conveyed by the registration roller 31 by the transfer roller 42 by electrostatic force and pressure, and the sheet electrostatically absorbed by the photosensitive drum 40 is charged by the supply charge of the sheet separating unit 8. When the potential on the back surface of the paper is removed, the paper is separated from the photosensitive drum 40. The separated sheet is sent to the heat fixing device 6, the toner image on the sheet is thermally fixed by the heat roller 60 of the heat fixing device 6, and is discharged to the stacker 14 by the discharge roller 36.
Similarly, the paper inserted by tilting the manual feed guide 32 is
The toner image on the photosensitive drum 40 is conveyed by the manual feed roller 33 in the direction of the photosensitive drum 40 and transferred by the transfer roller 42 by electrostatic force and pressure.
The sheet electrostatically attracted to the sheet is separated from the photosensitive drum 40 by the charge supplied to the sheet separating unit 8 and sent to the heat fixing unit 6, and the toner image on the sheet is thermally fixed by the heat roller 60 of the heat fixing unit 6. Then, the sheet is discharged to the stacker 14 by the discharge roller 36.

3, the front cover 10 is opened to the entire right side of the figure around the cover shaft 34. The front cover 10 includes a manual feed guide 32 and a manual feed roller. 33 and the paper separating unit 8
And a heat fixing device 6 and an upper discharge (drive) roller 36 a among the discharge rollers 36. The upper cover 11 is opened to the upper part of the apparatus above the figure around a shaft (not shown), and a lower discharge (pinch) roller 36b among the discharge rollers 36 is provided. Therefore, as shown in FIG. 3, when the front cover 10 is opened, the U-shaped conveyance path 3 from the registration roller 31 to the discharge roller 36 is opened, which is convenient for removing jammed paper. At this time, since the transfer roller 42 is provided on the process unit 2 side, the portion of the photosensitive drum 40 is not opened, but the transfer roller 42 is displaced in opposition to the photosensitive drum 40 (parallelism, position). Since the transfer operation cannot be performed satisfactorily, the transfer unit is provided on the process unit 2 side. Even if this portion is not opened, it does not mean that there is no problem in removing the jammed paper. Similarly, the reason why the entire heat fixing device 6 is provided on the front cover 10 is that when the heat fixing device 6 is divided so that the transport path can be opened, a part of the heat fixing device 6 is installed on the process unit 2. This is because it is inconvenient to take out the process unit 2, and even if this portion is not opened, there is no problem in removing jammed paper. In opening the cover, as shown in FIG. 1, the front cover 10 is disposed on the upper cover 11 at a discharge portion so that the upper cover 11 is not opened unless the front cover 10 is opened. . Therefore, as shown in FIG. 3, when the front cover 10 is opened and the upper cover 11 is opened, the upper part of the apparatus and a part of the entire surface are opened, and the toner cassette is maintained while the process unit 2 is installed from the front side of the apparatus. The toner cassette 56 can be easily removed and attached, and only the toner cassette 56 can be replaced. Further, since the front surface of the apparatus is opened by the front cover 10 and the upper part of the apparatus is opened by the upper cover 11, the process unit 2 can be easily taken out and attached, and even if the process unit 2 is large, replacement is easy. For this reason, the process unit 2 can be enlarged, and the developing device 5 in the process unit 2 can be enlarged, so that the amount of developer contained can be increased and the replacement cycle can be greatly extended. Further, since the developer can be supplied by replacing only the toner cassette 56, the replacement cycle can be further extended.

In the above embodiment, the following modifications are possible. (1) In the above-described embodiment, the process unit 2 is described as an electrophotographic mechanism of a charging, exposing, and developing type. However, the process unit 2 can be applied to another recording type that performs development. (2) Although the process unit 2 is replaceable by the user, the present invention can also be applied to a unit that cannot be replaced by the user. (3) The sheet PP is not limited to paper, and other media can be used. (4) The image forming apparatus has been described as a printer, but may be another image forming apparatus such as a copying machine or a facsimile.

(B) Preparation of fine particles Resin fine particles A 28 g of styrene, 2 g of butyl acrylate and 57 g of water were placed in a four-necked flask and placed in an oil bath at 80 ° C. 300 times /
For 5 minutes, and after purging with nitrogen for 15 minutes, V-5
0 (azo-based water-soluble initiator, Wako Pure Chemical Industries) was dissolved in 10 parts by weight of water, injected with a syringe, and polymerized for 4 hours. The average particle size of the obtained particles was about 0.4 μm. This particle
For 0.5 g, non-coated carrier (KBN-100,
(Hitachi Metals) 9.5 g was placed in a 50 cc polybin, stirred for 10 minutes, and the charge amount was measured by blow-off. As a result, +
335 μC / g. The glass transition temperature is 90
° C.

Resin Fine Particles B 28 g of styrene, 2 g of butyl acrylate and 57 g of water were placed in a four-necked flask and placed in an oil bath at 80 ° C. 300 times /
After stirring for 15 minutes and performing nitrogen replacement for 15 minutes, potassium peroxodisulfate (manufactured by Junsei Chemical) was dissolved in 10 parts by weight of water, injected with a syringe, and polymerized for 4 hours. The average particle size of the obtained particles was about 0.4 μm. This particle
For 0.5 g, non-coated carrier (KBN-100,
9.5 g was placed in a 50 cc poly bottle, stirred for 10 minutes, and the charge amount was measured by blow-off. as a result,
-55 [mu] C / g. The glass transition temperature is 89
° C.

Resin Fine Particles C 28 g of styrene, 2 g of butyl acrylate and 57 g of water were placed in a four-necked flask and placed in an oil bath at 80 ° C. 300 times /
After performing stirring for 15 minutes and performing nitrogen replacement for 15 minutes, a hydrogen peroxide solution was dissolved in 10 parts by weight of water and injected with a syringe.
The polymerization was carried out for 4 hours. The average particle size of the obtained particles is about 0.4
μm. To 0.5 g of the particles, 9.5 g of a non-coated carrier (KBN-100, manufactured by Hitachi Metals) was placed in a 50 cc polybin, stirred for 10 minutes, and the charge amount was measured by blow-off. As a result, it was -205 μC / g. The glass transition temperature was 85 ° C.

Resin fine particles D 24 g of styrene, 6 g of butyl acrylate (20 parts by weight of the whole monomer) and 57 g of water were placed in a four-necked flask.
After stirring 300 times / minute in an oil bath at 80 ° C. and performing nitrogen replacement for 15 minutes, V-50 (azo water-soluble initiator,
Was dissolved in 10 parts by weight of water, injected with a syringe, and polymerized for 4 hours. The average particle diameter of the obtained particles was about 0.4 μm. To 0.5 g of the particles, 9.5 g of a non-coated carrier (KBN-100, manufactured by Hitachi Metals) was placed in a 50 cc polybin, stirred for 10 minutes, and the charge amount was measured by blow-off. As a result, it was +117 μC / g. The glass transition temperature was 80 ° C.

Resin fine particles E 10 parts by weight of methyl methacrylate, 90 parts by weight of styrene, and 157 parts by weight of water were placed in a four-necked flask, and stirred in an oil bath at 80 ° C. 300 times / min. Was carried out, V-50 (azo-based water-soluble initiator, manufactured by Wako Pure Chemical Industries) was dissolved in 10 parts by weight of water, and injected with a syringe.
Polymerized for hours. As a result, the particle size dispersed in water 0.5μ
m polymer fine particles were obtained.

Resin fine particles F 90 parts by weight of methyl methacrylate, 10 parts by weight of styrene, 157 parts by weight of water, Neogen SC (manufactured by Daiichi Kogyo Seiyaku)
0.2 parts by weight was placed in a four-necked flask, stirred at 80 ° C. in an oil bath at 300 times / minute, and purged with nitrogen for 15 minutes. Then, 10 parts of potassium peroxodisulfate (manufactured by Junsei Chemical) was added.
It was dissolved in water by weight, injected with a syringe, and polymerized for 4 hours. As a result, polymer fine particles having a particle size of 0.1 μm dispersed in water were obtained.

Resin fine particles G 10 g of styrene, 90 g of methyl methacrylate and 15 g of water
7 g in a four-necked flask and placed in an oil bath at 80 ° C. for 30 minutes.
After stirring 0 times / minute and performing nitrogen replacement for 15 minutes,
V-50 (azo water-soluble initiator, manufactured by Wako Pure Chemical Industries) was dissolved in 10 parts by weight of water, injected with a syringe, and polymerized for 4 hours. The average particle diameter of the obtained particles was about 0.4 μm. For 0.5 g of the particles, a non-coated carrier (KB)
(N-100, manufactured by Hitachi Metals) 9.5 g was placed in a 50 cc poly bottle, stirred for 10 minutes, and the charge amount was measured by blow-off. As a result, it was +235 μC / g. The glass transition temperature was 100 ° C.

Resin fine particles H 10 g of styrene, 90 g of methyl methacrylate and 15 g of water
7 g in a four-necked flask and placed in an oil bath at 80 ° C. for 30 minutes.
After stirring 0 times / minute and performing nitrogen replacement for 15 minutes,
Potassium peroxodisulfate (manufactured by Junsei Chemical) was dissolved in 10 parts by weight of water, injected with a syringe, and polymerized for 4 hours.
The average particle size of the obtained particles was about 0.4 μm. To 0.5 g of the particles, a non-coated carrier (KBN-10) was used.
0, made by Hitachi Metals)
After stirring for minutes, the charge amount was measured by blow-off. As a result, it was -155 µC / g. The glass transition temperature was 101 ° C.

Resin fine particles I 10 g of styrene, 90 g of methyl methacrylate and 15 g of water
7 g in a four-necked flask and placed in an oil bath at 80 ° C. for 30 minutes.
After stirring 0 times / minute and performing nitrogen replacement for 15 minutes,
Hydrogen peroxide solution was dissolved in 10 parts by weight of water, injected with a syringe, and polymerized for 4 hours. The average particle size of the obtained particles was about 0.4 μm. To 0.5 g of the particles, 9.5 g of a non-coated carrier (KBN-100, manufactured by Hitachi Metals) was added.
After placing in a 0 cc polybin and stirring for 10 minutes, the charge amount was measured by blow-off. As a result, it was -125 µC / g. The glass transition temperature was 101 ° C.

Resin fine particles J 30 g of styrene, 70 g of methyl methacrylate and 15 g of water
7 g in a four-necked flask and placed in an oil bath at 80 ° C. for 30 minutes.
After stirring 0 times / minute and performing nitrogen replacement for 15 minutes,
V-50 (azo water-soluble initiator, manufactured by Wako Pure Chemical Industries) was dissolved in 10 parts by weight of water, injected with a syringe, and polymerized for 4 hours. The average particle size of the obtained particles was about 0.4 μm.
Non-coated carrier (KBN-
100, made by Hitachi Metals) Put 9.5g in 50cc poly bottle,
After stirring for 10 minutes, the charge amount was measured by blow-off. As a result, it was +217 μC / g. The glass transition temperature was 102 ° C.

Resin fine particle K 10 g of styrene, 2-ethylhexyl methacrylate 9
0 g and 157 g of water were placed in a four-necked flask, stirred 300 times / min in an oil bath at 80 ° C., and purged with nitrogen for 15 minutes. Then, V-50 (azo-based water-soluble initiator, Was dissolved in 10 parts by weight of water and injected with a syringe.
Polymerized for hours. The average particle size of the obtained particles is about 0.4μ
m. To 0.5 g of the particles, 9.5 g of a non-coated carrier (KBN-100, manufactured by Hitachi Metals) was placed in a 50 cc polybin, stirred for 10 minutes, and the charge amount was measured by blow-off. As a result, it was +135 μC / g. The glass transition temperature was 40 ° C.

(C) Production of toner Toner A (pulverization method) Styrene-acrylic resin (CPR) is used as a binder resin.
-300, manufactured by Mitsui Toatsu) (90 parts by weight) and carbon black (Black Pearls L; average particle size: 2.) as a coloring material.
4mμ, specific surface area: 138m ² / g; manufactured by Cabot Corporation)
5 parts by weight, 1 part by weight of an azo dye (manufactured by Bontron S-34 Orient Chemical), and 4 parts by weight of propylene wax (Viscol 550P manufactured by Sanyo Chemical) are melted and kneaded at 160 ° C. for 30 minutes using a pressure kneader to form a toner mass. Obtained.
The cooled toner mass is reduced to approx.
2 mm coarse toner was obtained. Next, the coarse toner is finely pulverized using a jet mill (PJM pulverizer, manufactured by Nippon Pneumatic Industries), and the pulverized material is classified into an air classifier (manufactured by Alpine).
To obtain a toner A having a particle size of 5 to 20 μm.
For 0.5 g of this toner, a non-coated carrier (KBN)
(9.5, manufactured by Hitachi Metals), 9.5 g was placed in a 50 cc polybin, stirred for 10 minutes, and the charge amount was measured by blow-off. As a result, it was -10 μC / g.

Toner B (emulsion polymerization) Monomer Styrene (manufactured by Wako Pure Chemical) 90 parts by weight Butyl acrylate (manufactured by Wako Pure Chemical) 10 parts by weight n-butyl methacrylate (manufactured by Wako Pure Chemical) 5 parts by weight Colorant carbon black ( 2 parts by weight Azochrome dye (S-34, manufactured by Orient) 2 parts by weight Emulsifier Neogen SC (manufactured by Daiichi Kogyo Seiyaku) 0.2 parts by weight Thermal polymerization initiator N-50 (manufactured by Wako Pure Chemical Industries, Ltd.) ) 0.2 parts by weight

The monomer, colorant and wax were stirred for 53 minutes using a disperser (Yamato Kagaku) to prepare a monomer composition. Next, this monomer composition was placed in 500 parts by weight of distilled water to which a polymerization initiator and an emulsifier had been added, and a disperser (4,000 rpm) was added at room temperature (20 ° C.).
And stirred for 3 minutes. After that, the disperser was changed to a three-one motor, and the mixture was heated to 60 ° C. while stirring at 100 rpm to completely polymerize the monomer composition (1).
３3 μm). Next, the resulting fine particles dispersed in water are heated to 80 ° C. to aggregate the particles, and the average particle diameter dispersed in water is 6 μm.
m was obtained. For 0.5 g of this toner,
Non-coated carrier (KBN-100, manufactured by Hitachi Metals)
9.5 g was placed in a 50 cc polybin, stirred for 10 minutes, and the charge amount was measured by blow-off. As a result, -11 μC /
g.

Toner C (suspension polymerization) Monomer Styrene (manufactured by Wako Pure Chemical) 90 parts by weight Butyl acrylate (manufactured by Wako Pure Chemical) 10 parts by weight Colorant Carbon black (150T, manufactured by Degussa) 2 parts by weight Azochrome dye ( S-34, manufactured by Orient) 2 parts by weight Suspension polyvinyl alcohol (manufactured by Wako Pure Chemical) 0.2 part by weight Thermal polymerization initiator N-65 (manufactured by Wako Pure Chemical) 0.2 part by weight Benzoin (manufactured by Midori Kagaku) ) 0.2 parts by weight

The above monomer, colorant and wax were stirred for 3 minutes using a disperser (manufactured by Yamato Kagaku) to prepare a monomer composition. Next, this monomer composition was placed in 500 parts by weight of distilled water to which a polymerization initiator and a suspending agent had been added, and the mixture was dispersed at room temperature (20 ° C.) with a disperser (4,000 rpm).
And stirred for 3 minutes. Thereafter, the mixture was heated to 60 ° C. and a xenon lamp was turned on to completely polymerize the monomer composition. As a result, a negatively chargeable toner having an average particle diameter of 6 μm dispersed in water was obtained. For 0.5 g of this toner, 9.5 g of non-coated carrier (KBN-100, manufactured by Hitachi Metals)
Was placed in a 50 cc polybin, stirred for 10 minutes, and the charge amount was measured by blow-off. As a result, it was -11 μC / g.

Preparation of Toner D (d) Seed Particles 29 parts by weight of styrene and 57 parts by weight of water are placed in a four-necked flask, and stirred in an oil bath at 80 ° C. 300 times / min.
After performing nitrogen replacement for 15 minutes, potassium peroxodisulfate was dissolved in 10 g of water, and injected with a syringe.
The polymerization was carried out for 8 hours. The average particle diameter of the obtained particles is about 1 μm.
m.

(Swelling of Seed Particles) The polymer particles 1 part by weight Lauryl chloride (manufactured by Wako Pure Chemical) 4 parts by weight Water 25 parts by weight Benzoyl peroxide (manufactured by Wako Pure Chemical Industries) 2.5 parts by weight 1,2-dichloroethane ( 12 parts by weight Sodium lauryl sulfate (Tokyo Kasei Kogyo) 0.25 parts by weight Acetone 4 parts by weight

Using the polymer particles as seed particles, a toner was produced in the following swelling process. First, benzoyl peroxide was dissolved in 1,2-dichloroethane, and sufficiently emulsified and dispersed with a homogenizer together with the remaining reagents. This mixture and the seed particles were placed in a four-necked flask, and 35
Stirring was performed at 400 ° C./min for 10 hours at a temperature of 400 ° C., and the water-insoluble substance containing the initiator was absorbed by the seed particles.

(E) Preparation of toner particles Styrene (manufactured by Wako Pure Chemical Industries) 82 parts by weight n-butyl acrylate (manufactured by Wako Pure Chemical Industries) 10 parts by weight Sodium lauryl sulfate (manufactured by Tokyo Chemical Industry) 0.25 parts by weight Mitsubishi Carbon Black MA-600 (Mitsubishi Chemical) 5 parts by weight S-34 (Orient) 3 parts by weight

A monomer, sodium lauryl sulfate, and 200 parts by weight of water were added to the above latex by emulsifying and dispersing.
The solution was stirred at 400 ° C./min at 30 ° C. for 24 hours for absorption.
Carbon black and S-34 are homogenized in water 10
A solution sufficiently dispersed in 0 parts by weight was added, and the temperature was increased to 70 ° C. with stirring in the same manner to carry out polymerization for 24 hours.
The conversion rate of the finally obtained toner was 80%, the average particle diameter was 6.0 μm, and the degree of dispersion of the particle diameter was 5%. For 0.5 g of this toner, a non-coated carrier (KBN-10)
0, made by Hitachi Metals)
After stirring for minutes, the charge amount was measured by blow-off. As a result, it was -10 μC / g.

Toner E (emulsion polymerization) Monomer Styrene (manufactured by Wako Pure Chemical) 45 parts by weight Butyl acrylate (manufactured by Wako Pure Chemical) 10 parts by weight n-butyl methacrylate (manufactured by Wako Pure Chemical) 5 parts by weight Colorant carbon black ( 2 parts by weight Azochrome dye (S-34, manufactured by Orient) 2 parts by weight Emulsifier Neogen SC (manufactured by Daiichi Kogyo Seiyaku) 0.2 parts by weight Thermal polymerization initiator N-50 (manufactured by Wako Pure Chemical Industries, Ltd.) ) 0.2 parts by weight Magnetic powder KBC-100 (manufactured by Kanto Denka) 45 parts by weight

The above monomer, colorant and wax were stirred for 3 minutes using a disperser (manufactured by Yamato Kagaku) to prepare a monomer composition. Next, this monomer composition was placed in 500 parts by weight of distilled water to which a polymerization initiator and an emulsifier had been added, and a disperser (4,000 rpm) was added at room temperature (20 ° C.).
And stirred for 3 minutes. After that, the disperser was changed to a three-one motor, and the mixture was heated to 60 ° C. while stirring at 100 rpm to completely polymerize the monomer composition (1).
３3 μm). Next, the resulting fine particles dispersed in water are heated to 80 ° C. to aggregate the particles, and the average particle diameter dispersed in water is 6 μm.
m was obtained.

Toner F (suspension polymerization) Monomer Styrene (manufactured by Wako Pure Chemical) 45 parts by weight Butyl acrylate (manufactured by Wako Pure Chemical) 10 parts by weight Colorant Carbon black (150T, manufactured by Degussa) 2 parts by weight Azochrome dye (S-34, manufactured by Orient) 2 parts by weight Suspension polyvinyl alcohol (Wako Pure Chemical) 0.2 parts by weight Thermal polymerization initiator N-65 (Wako Pure Chemicals) 0.2 parts by weight Benzoin (manufactured by Midori Kagaku) ) 0.2 parts by weight Magnetic powder KBC-100 (manufactured by Kanto Denka) 45 parts by weight

The above monomer, colorant and wax were stirred for 3 minutes using a disperser (manufactured by Yamato Scientific Co., Ltd.) to prepare a monomer composition. Next, this monomer composition was placed in 500 parts by weight of distilled water to which a polymerization initiator and a suspending agent had been added,
The mixture was stirred at room temperature (20 degrees) using a disperser (4,000 rpm) for 3 minutes. Thereafter, the mixture was heated to 60 ° C. and a xenon lamp was turned on to completely polymerize the monomer composition. As a result, a negatively chargeable toner having an average particle diameter of 6 μm dispersed in water was obtained. To 0.5 g of the toner, 9.5 g of a non-coated carrier (KBN-100, manufactured by Hitachi Metals) was placed in a 50 cc polybin, stirred for 10 minutes, and the charge amount was measured by blow-off. As a result, it was -11 μC / g.

Example 1 Toner A was silica (R972D, Nippon Aerosil) 0.3
Parts by weight and 0.05 parts by weight of resin fine particles A were externally added for 3 minutes at a rotation speed of 650 rpm using a Henschel mixer.
After charging the toner into the apparatus shown in FIG.
Left for 12 hours in RH environment. Thereafter, printing was performed, and the background fog of the paper was observed. As a result, there was no background fog, and good printing was obtained. In order to measure the charge distribution of the toner, an apparatus equipped with the present developing device in an E-SPART analyzer manufactured by Hosokawa Micron was used (FIG. 5), and the charge distribution of the toner was measured (FIG. 5). Further, continuous printing of 20,000 sheets was performed in the high-temperature and high-humidity environment described above. As a result, there was no fusion of the toner to the layer-thickness regulating member and the toner carrier, and good printing characteristics as in the initial stage were obtained.

Example 2 Toner A was made of silica (R972D, manufactured by Nippon Aerosil)
0.3 parts by weight of the resin fine particles A and 0.7 parts by weight of the resin fine particles A were externally added for 3 minutes at a rotation speed of 650 rpm using a Henschel mixer. After charging this toner into the apparatus shown in FIG.
It was left in an 80% RH environment for 12 hours. Thereafter, printing was performed, and the background fog of the paper was observed. As a result, there was no background fog, and good printing was obtained. Although continuous printing of 20,000 sheets was performed in this environment, the toner was not fused to the layer thickness regulating member or the toner carrier, and good printing characteristics as in the initial stage were obtained.

Example 3 Toner A was silica (R972D, manufactured by Nippon Aerosil)
0.3 parts by weight and 0.5 parts by weight of the resin fine particles A were externally added for 3 minutes at a rotation speed of 650 rpm using a Henschel mixer. After charging this toner into the apparatus shown in FIG.
It was left in an 80% RH environment for 12 hours. Thereafter, printing was performed, and the background fog of the paper was observed. As a result, there was no background fog, and good printing was obtained. Although continuous printing of 20,000 sheets was performed in this environment, the toner was not fused to the layer thickness regulating member or the toner carrier, and good printing characteristics as in the initial stage were obtained.

Comparative Example 1 Toner A was made of silica (R972D, manufactured by Nippon Aerosil)
0.3 parts by weight and 0.04 parts by weight of the resin fine particles A were externally added at 650 rpm for 3 minutes using a Henschel mixer. After charging this toner into the apparatus shown in FIG.
It was left in an 80% RH environment for 12 hours. Thereafter, printing was performed, and the background fog of the paper was observed. As a result, some background fog was recognized.

Comparative Example 2 Toner A was silica (R972D, manufactured by Nippon Aerosil)
Only 0.3 parts by weight was externally added for 3 minutes at 650 rpm using a Henschel mixer. After this toner was put into the apparatus shown in FIG. 3, it was left in an environment of 40 ° C. and 80% RH for 12 hours. Thereafter, printing was performed and the background fog of the paper was observed. As a result, the entire surface of the paper was stained by the background fog. Further, the charge amount distribution of this toner was measured, and
(FIG. 5).

Comparative Example 3 Toner A was silica (R972D, manufactured by Nippon Aerosil)
0.3 parts by weight and 3 parts by weight of the resin fine particles A were externally added at 650 rpm for 3 minutes using a Henschel mixer. After charging the toner into the apparatus shown in FIG.
It was left in a 0% RH environment for 12 hours. Thereafter, printing was performed, and when the background fog of the paper was observed, there was no background fog. However, since the particles A were selectively discharged to the printing background portion of the photoconductor drum, the photoconductor became white and continuous. Printing is blurred with printing. In addition, particles were accumulated on the cleaning blade, the photoreceptor was shaved, and the bright portion potential increased by -50 V and the dark portion potential decreased by -100 V.

Comparative Example 4 Toner A was silica (R972D, manufactured by Nippon Aerosil)
0.3 parts by weight and 0.5 parts by weight of resin fine particles B were externally added for 3 minutes at a rotation speed of 650 rpm using a Henschel mixer. After charging this toner into the apparatus shown in FIG.
It was left in an 80% RH environment for 12 hours. Thereafter, printing was performed and the background fog of the paper was observed. As a result, the entire surface of the paper was stained by the background fog.

Comparative Example 5 Toner A was silica (R972D, manufactured by Nippon Aerosil)
0.3 parts by weight and 0.5 parts by weight of the resin fine particles C were externally added for 3 minutes at a rotation speed of 650 rpm using a Henschel mixer. After charging this toner into the apparatus shown in FIG.
It was left in an 80% RH environment for 12 hours. Thereafter, printing was performed and the background fog of the paper was observed. As a result, the entire surface of the paper was stained by the background fog.

Comparative Example 6 Silica (R972D, manufactured by Nippon Aerosil Co., Ltd.) was used as toner A
0.3 parts by weight and 0.5 parts by weight of the resin fine particles D were externally added for 3 minutes at a rotation speed of 650 rpm using a Henschel mixer. After charging this toner into the apparatus shown in FIG.
It was left in an 80% RH environment for 12 hours. Thereafter, printing was performed and the background fog of the paper was observed. As a result, the background fog was good. Then, when continuous printing was performed, the resin fine particles D were fused to the layer thickness regulating member on 5000 sheets, and white streaks were generated in printing.

Example 4 Toner B used silica (R972D, manufactured by Nippon Aerosil)
0.3 parts by weight and 0.5 parts by weight of the resin fine particles A were externally added for 3 minutes at a rotation speed of 650 rpm using a Henschel mixer. After charging this toner into the apparatus shown in FIG.
It was left in an 80% RH environment for 12 hours. Thereafter, printing was performed, and the background fog of the paper was observed. As a result, there was no background fog, and good printing was obtained. Although continuous printing of 20,000 sheets was performed in this environment, good printing characteristics were obtained, which were the same as those in the initial stage.

Example 5 Toner C was silica (R972D, manufactured by Nippon Aerosil)
0.3 parts by weight and 0.5 parts by weight of the resin fine particles A were externally added for 3 minutes at a rotation speed of 650 rpm using a Henschel mixer. After charging this toner into the apparatus shown in FIG.
It was left in an 80% RH environment for 12 hours. Thereafter, printing was performed, and the background fog of the paper was observed. As a result, there was no background fog, and good printing was obtained. Although continuous printing of 20,000 sheets was performed in this environment, good printing characteristics were obtained, which were the same as those in the initial stage.

Example 6 Toner D was silica (R972D, manufactured by Nippon Aerosil)
0.3 parts by weight and 0.5 parts by weight of the resin fine particles A were externally added for 3 minutes at a rotation speed of 650 rpm using a Henschel mixer. After charging this toner into the apparatus shown in FIG.
It was left in an 80% RH environment for 12 hours. Thereafter, printing was performed, and the background fog of the paper was observed. As a result, there was no background fog, and good printing was obtained. Although continuous printing of 20,000 sheets was performed in this environment, good printing characteristics were obtained, which were the same as those in the initial stage.

Example 7 A toner A and a dispersion solution of fine resin particles E were mixed (toner /
Polymer fine particles = 100 / 0.5), and stirred with a three-one motor to obtain a uniform dispersion of toner and resin fine particles.
Dry at ℃. 200 g of the toner was put into the apparatus shown in FIG. 3 and a printing test was carried out. As a result, good printing quality was obtained without uneven printing or fogging. Next, when continuous printing of 50k sheets was performed, the charge amount was 15 ± 2 μC.
/ G, and the printing quality was good.

Example 8 Toner B and a dispersion solution of resin fine particles E were mixed (toner /
Polymer fine particles = 100 / 0.5), and stirred with a three-one motor to obtain a uniform dispersion of toner and resin fine particles.
Dry at ℃. 200 g of the toner was put into the apparatus shown in FIG. 3 and a printing test was carried out. As a result, good printing quality was obtained without uneven printing or fogging.

Example 9 A toner C and a dispersion solution of resin fine particles E were mixed (toner /
Polymer fine particles = 100 / 0.5), and stirred with a three-one motor to obtain a uniform dispersion of toner and resin fine particles.
Dry at ℃. 200 g of the toner was put into the apparatus shown in FIG. 3 and a printing test was carried out. As a result, good printing quality was obtained without uneven printing or fogging.

Example 10 Toner D and a dispersion solution of fine resin particles E were mixed (toner /
Polymer fine particles = 100 / 0.5), and stirred with a three-one motor to obtain a uniform dispersion of toner and resin fine particles.
Dry at ℃. 200 g of the toner was put into the apparatus shown in FIG. 3 and a printing test was carried out. As a result, good printing quality was obtained without uneven printing or fogging.

Example 11 Toner B and a dispersion solution of fine resin particles F were mixed (toner /
Polymer fine particles = 100 / 0.5), and stirred with a three-one motor to obtain a uniform dispersion of toner and resin fine particles.
Dry at ℃. 200 g of the toner was put into the apparatus shown in FIG. 3 and a printing test was carried out. As a result, good printing quality was obtained without uneven printing or fogging.

Example 12 Toner B and a dispersion solution of fine resin particles F were mixed (toner /
Polymer fine particles = 100 / 0.5), and stirred with a three-one motor to obtain a uniform dispersion of toner and resin fine particles.
Dry at ℃. A two-component developer is prepared using 30 g of the toner and 590 g of the ferrite carrier.
As a result of performing a printing test using 6174 (manufactured by Fujitsu), good printing quality was obtained without printing unevenness or fogging.

Example 13 Toner E and a dispersion solution of fine resin particles F were mixed (toner /
Polymer fine particles = 100 / 0.5), and stirred with a three-one motor to obtain a uniform dispersion of toner and resin fine particles.
Dry at ℃. A 1.5-component developer was prepared using 150 g of the toner and 36 g of the ferrite carrier, and a printing test was carried out using a printer FMLBP112 (manufactured by Fujitsu). As a result, good print quality was obtained without uneven printing or fogging.

Comparative Example 7 A dispersion solution of the toner B and the resin fine particles E was dried at 60 ° C., respectively. This toner and resin fine particles were mixed with a Henschel mixer (toner / polymer fine particles = 100/0.
Five). 200 g of the toner is put into the apparatus shown in FIG.
As a result of the printing test, it adhered to the printing background portion on the photosensitive member, and uneven printing occurred on 20 sheets.

Comparative Example 8 A dispersion solution of toner B and resin fine particles F was dried at 60 ° C., respectively. This toner and resin fine particles were mixed with a Henschel mixer (toner / polymer fine particles = 100/0.
Five). 30 g of this toner and 590 g of ferrite carrier
To prepare a two-component developer using a printer F6174.
As a result of performing a printing test using (manufactured by Fujitsu), fog appeared from the beginning.

Comparative Example 9 A dispersion solution of toner E and resin fine particles E was dried at 60 ° C., respectively. This toner and polymer fine particles were mixed with a Henschel mixer (toner / polymer fine particles = 100/0.
Five). 150 g of this toner and 36 g of ferrite carrier
To produce a 1.5-component developer using a printer FMLBP
As a result of a print test using the 112 (manufactured by Fujitsu),
The toner adhered to the printing background portion on the photoreceptor, and printing unevenness occurred on 100 sheets.

Example 14 Toner B was silica (R972D, manufactured by Nippon Aerosil Co., Ltd.)
0.1 parts by weight and 0.05 parts by weight of resin fine particles G were externally added at a rotation speed of 650 rpm for 3 minutes using a Henschel mixer. The toner was transferred by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine using a urethane rubber roller of a printer F6144A1 (manufactured by Fujitsu). As a result, good printing was obtained without any hollow in the characters. Further, continuous printing of 20,000 sheets was performed in the high-temperature, high-humidity environment described above. However, the photoconductor of the OPC was only scraped by 0.8 μm, and good printing characteristics as in the initial stage were obtained.

Example 15 Toner B used silica (R972D, manufactured by Nippon Aerosil Co., Ltd.)
0.1 parts by weight and 0.9 parts by weight of the resin fine particles G were externally added at a rotation speed of 650 rpm for 3 minutes using a Henschel mixer. The toner was transferred by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine of a printer F6144A1 (manufactured by Fujitsu). As a result, good printing was obtained without any voids in the characters. In addition, 20,000 sheets were continuously printed in the high-temperature, high-humidity environment described above.
Only 0.8 μm was scraped, and good printing characteristics were obtained, which were the same as those at the initial stage.

Example 16 Toner B used silica (R972D, manufactured by Nippon Aerosil Co., Ltd.)
0.1 parts by weight and 0.5 parts by weight of the resin fine particles G were externally added for 3 minutes at 650 rpm using a Henschel mixer. The toner was transferred by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine of a printer F6144A1 (manufactured by Fujitsu). As a result, good printing was obtained without any voids in the characters. In addition, 20,000 sheets were continuously printed in the high-temperature, high-humidity environment described above.
Only 0.8 μm was scraped, and good printing characteristics were obtained, which were the same as those at the initial stage.

Comparative Example 10 Toner B was silica (R972D, manufactured by Nippon Aerosil)
0.1 parts by weight and 0.04 parts by weight of resin fine particles G were externally added at a rotation speed of 650 rpm for 3 minutes using a Henschel mixer. The toner was transferred by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine of a printer F6144A1 (manufactured by Fujitsu). As a result, hollow characters occurred.

Comparative Example 11 Toner B was used with silica (R972D, manufactured by Nippon Aerosil Co., Ltd.)
0.1 parts by weight, using a Henschel mixer, rotation speed
External addition was performed at 650 rpm for 3 minutes. The toner was transferred by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine of a printer F6144A1 (manufactured by Fujitsu).
As a result, hollow characters occurred. This printing was compared with the printing of Example 14 (FIG. 7).

Comparative Example 12 Toner B was silica (R972D, manufactured by Nippon Aerosil)
0.1 parts by weight and 2 parts by weight of resin fine particles G were externally added for 3 minutes at 650 rpm using a Henschel mixer. This toner is used in a printer F6144A1 (manufactured by Fujitsu).
When a transfer was performed by applying a constant voltage of 1.2 KV using the roller transfer remodeling machine, particles G adhered to the photoreceptor drum, so that the photoreceptor became white and printing was blurred with continuous printing. Further, particles are accumulated on the cleaning blade, the photoreceptor is shaved, and the light portion potential is -50V.
As a result, the dark portion potential decreased by -100 V.

Comparative Example 13 Toner B used silica (R972D, manufactured by Nippon Aerosil)
0.1 parts by weight and 0.5 parts by weight of the resin fine particles H were externally added for 3 minutes at 650 rpm using a Henschel mixer. The toner was transferred by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine of a printer F6144A1 (manufactured by Fujitsu). As a result, voids in the printed characters were not eliminated.

Comparative Example 14 Toner B used silica (R972D, manufactured by Nippon Aerosil Co., Ltd.)
0.1 parts by weight and 0.5 parts by weight of the resin fine particles I were externally added for 3 minutes at 650 rpm using a Henschel mixer. The toner was transferred by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine of a printer F6144A1 (manufactured by Fujitsu). As a result, voids in the printed characters were not eliminated.

Comparative Example 15 Toner B was silica (R972D, manufactured by Nippon Aerosil)
0.1 parts by weight and 0.5 parts by weight of resin fine particles J were externally added at a rotation speed of 650 rpm for 3 minutes using a Henschel mixer. The toner was transferred by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine of a printer F6144A1 (manufactured by Fujitsu). As a result, it was good for the void in the characters. Then, when continuous printing was performed, printing became blurred on 10,000 sheets. At this time, the abrasion of the photoreceptor reached 8 μm, the bright portion potential increased by −50 V, and the dark portion potential decreased by −100 V.

Comparative Example 16 Toner B used silica (R972D, manufactured by Nippon Aerosil)
0.1 parts by weight and 0.5 parts by weight of the resin microparticles K were externally added at 650 rpm for 3 minutes using a Henschel mixer. The toner was transferred by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine of a printer F6144A1 (manufactured by Fujitsu). As a result, it was good for the void in the characters. Then, when continuous printing was performed, a fused film of resin was formed on the photoreceptor surface on 2,000 sheets, and the printing became thin.

Example 17 Toner A was silica (R972D, manufactured by Nippon Aerosil Co., Ltd.)
0.1 parts by weight and 0.5 parts by weight of the resin fine particles G were externally added for 3 minutes at 650 rpm using a Henschel mixer. The toner was transferred by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine of a printer F6144A1 (manufactured by Fujitsu). As a result, good printing was obtained without any voids in the characters. In addition, 20,000 sheets were continuously printed in the high-temperature, high-humidity environment described above.
Only 0.8 μm was scraped, and good printing characteristics were obtained, which were the same as those at the initial stage.

Example 18 Toner F was silica (R972D, manufactured by Nippon Aerosil)
0.1 parts by weight and 0.5 parts by weight of the resin fine particles G were externally added for 3 minutes at 650 rpm using a Henschel mixer. The toner was transferred by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine of a printer FMLBP112 (manufactured by Fujitsu). As a result, good printing was obtained without any voids in the characters. In addition, 20,000 sheets were continuously printed in the high-temperature, high-humidity environment described above.
Only 1.2 μm was scraped off, and good printing characteristics were obtained, which were the same as those at the initial stage.

Example 19 Toner D was silica (R972D, manufactured by Nippon Aerosil Co., Ltd.)
0.1 parts by weight and 0.5 parts by weight of the resin fine particles G were externally added for 3 minutes at 650 rpm using a Henschel mixer. This toner is transferred to printer F6144A1 (Fujitsu)
The transfer was performed by applying a constant voltage of 1.2 KV using a roller transfer remodeling machine of No. As a result, good printing was obtained without any voids in the characters. In addition, 20,000 sheets were continuously printed in the high-temperature, high-humidity environment described above.
Only 1.0 μm was scraped off, and good printing characteristics were obtained, which were the same as those at the initial stage.

[0095]

According to the present invention, in a non-magnetic one-component developing system, even when continuous printing is performed in a high-temperature and high-humidity environment, there is no background fog and a non-magnetic one which can maintain good print quality for a long time. A one-component developing toner is provided. Further, there is provided a method of manufacturing a toner for developing an electrostatic image, which does not cause unevenness in printing, fogging of a background portion, or charge fluctuation during continuous printing. There is provided a method capable of maintaining good printing quality for a long period without hollowing.

[Brief description of the drawings]

FIG. 1 is a sectional view of an image forming apparatus used in Examples and Comparative Examples.

FIG. 2 is a configuration diagram of a process unit to which a non-magnetic one-component developer used in Examples and Comparative Examples is applied.

FIG. 3 is an explanatory diagram of an image forming apparatus used in Examples and Comparative Examples.

FIG. 4 is a diagram showing a structure of an analyzer for measuring a charge distribution of a toner.

FIG. 5 is a graph showing a charge amount distribution of toner in Example 1 and Comparative Example 1.

FIG. 6 is a schematic diagram showing the middle of a character.

FIG. 7 is a comparison diagram of printing between Example 14 and Comparative Example 11.

[Explanation of symbols]

 2 Process Unit 4 Drum Cartridge 5 Developing Unit 6 Thermal Fixing Unit 7 Optical Unit 8 Paper Separation Unit 10 Front Cover 12 Paper Cassette 14 Stacker 14 30 Pickup Roller 31 Registration Roller 32 Manual Feed Guide 33 ... Manual feed roller 34 ... Cover shaft 36 ... Discharge roller 40 ... Photosensitive drum 41 ... Charge roller 42 ... Transfer roller 43 ... Waste toner box 44 ... Scraping blade 45 ... Handle 46 ... Roller cover 50 ... Developing roller 50a ... Power supply 51 ... Layer thickness regulating blade 52 Reset roller 53, 54 Paddle roller 55 Cassette storage unit 56 Toner cassette 57 Toner supply lever 58 Handle 59 Paper guide rib 60 Heat roller 61 Backup roller 62 Cleaning roller

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Norio Saruwatari Fujitsu Limited, 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa

Claims (1)

[Claims] 1. An external additive comprising toner particles having a volume average particle size of 4 to 15 μm and polymer fine particles having a particle size of 0.1 to 1 μm obtained from at least one selected from an acrylic monomer, a methacrylic monomer, and a styrene monomer. Wherein the toner particles and the polymer fine particles are separately formed in water by a polymerization method from a monomer, and then uniformly mixed in water in the same container. Wherein the polymer fine particles are directly externally added to the toner particles by drying.