JP2750561B2 - Non-magnetic one-component development method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact type non-magnetic one-component developing method for developing an electrostatic latent image using a non-magnetic toner.

[0002]

2. Description of the Related Art In general, in electrophotography, an electric latent image is formed on a photosensitive drum, the latent image is developed with toner, and a toner image is transferred to a transfer material such as paper as necessary. Thereafter, the image is fixed by means such as heating and pressing to obtain a copy. As a developer used in such an electrophotographic method, there are a two-component developer including a toner and a carrier, and a one-component developer having both functions of a toner and a carrier. One-component developers are further classified into magnetic one-component developers and non-magnetic one-component developers. The two-component developer has excellent electrophotographic properties such as transferability, fixability, and environmental resistance, but requires a toner concentration sensor to control the mixing ratio of toner and carrier, and has a short developer life. And a problem that the stirring mechanism of the developer becomes complicated. On the other hand, the magnetic one-component developer does not require the above-mentioned toner concentration sensor, and can easily reduce the size of the developing device, but has a problem that the fixing property is inferior because it contains magnetic particles. In view of such a background, a method using a non-magnetic toner as a one-component developer has recently been proposed and put into practical use in order to achieve both the simplification of the apparatus and the fixing characteristics.

A one-component developing method using a non-magnetic toner includes a contact type non-magnetic one-component developing method in which a developing roller carrying a developer is brought into contact with a photosensitive drum having an electrostatic latent image to perform development. There is a non-contact type non-magnetic one-component developing method in which a certain gap is provided between a roller and a photosensitive drum to fly and develop non-magnetic toner on a developing roller. In the non-contact type non-magnetic one-component developing method, since the thin layer of the developer must be formed uniformly on the developing roller, the distance between the developer and the layer regulating member is designed to be very small. As a result, in the conventional non-magnetic one-component developing method, the mechanical load given to the developer is large, and the problem that the developer is fused to the layer regulating member due to frictional heat generated by the contact and sliding occurs. I was When the developer is fused to the layer regulating member, the triboelectricity of the developer is impaired, and the developer becomes difficult to be charged. As a result, the phenomenon that the developer adheres to the non-image area, that is, the fog or the developer This causes a problem of so-called scattering.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional situation. Therefore, an object of the present invention is to provide a non-magnetic one-component developer which does not fuse with the layer-regulating member when contacted with the layer-regulating member and can obtain good developability without fogging or scattering. An object of the present invention is to provide a developing method.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a non-magnetic one-component developer having at least 13 carbon atoms can be used.
Addition of organic peroxide having alkyl group to polymerizable monomer
After dispersing , using a spherical toner by a suspension polymerization method to which a polymerization initiator was added , and further, by adhering fine particles containing cerium oxide, silicon carbide or magnetic particles to the surface of the spherical toner, The present inventors have found that it is possible to provide a non-magnetic one-component developing method having good developability without fusing the toner to the layer regulating member, which is the object, and have completed the present invention. That is, in the present invention, a non-magnetic one-component developer is supplied to a developing roller, a thin layer of the non-magnetic one-component developer is formed on the surface of the developing roller by a layer regulating member, and a charge is given to the photosensitive drum. A non-contact type non-magnetic one-component developing method in which the non-magnetic one-component developer is caused to fly by a potential difference from a roller and developed in a non-contact manner on a photosensitive drum holding an electrostatic latent image, and then transferred to a transfer material. hand,
The non-magnetic one-component developer is an alkyl having 13 or more carbon atoms.
Organic peroxide having a group is added to the polymerizable monomer and dispersed.
And a fine particle containing at least one selected from cerium oxide, silicon carbide and magnetic particles is adhered to the surface of a non-magnetic toner obtained by a suspension polymerization method to which a polymerization initiator is added. This is a non-magnetic one-component developing method.

Hereinafter, the present invention will be described in detail. FIG.
FIG. 1 is a schematic configuration diagram of a developing device used in a non-contact non-magnetic one-component developing method of the present invention. In the figure, 1 is a photosensitive drum, 2
Is a hopper, 3 is a non-magnetic one-component developer, 4 is a layer regulating member, 5 is a developing roller using an aluminum sleeve that carries the non-magnetic one-component developer, and 6 is a non-magnetic one-component developer leakage prevention member. , 7 are agitators. In this developing device, an electrostatic latent image is formed on the photosensitive drum 1 by a known electrophotographic method. A non-magnetic one-component developer 3 is accommodated in the hopper 2. The non-magnetic one-component developer 3 is supported on the developing roller 5 by a layer regulating member 4 so as to have a constant layer thickness. Electric charge is applied by friction with the regulating member 4. The developing roller 5 is provided with a gap of 120 μm to 300 μm with the photosensitive drum 1. A DC or AC voltage bias is applied to the developing roller. The non-magnetic one-component developer carried on the developing roller 5 is transported by the rotation of the developing roller 5 and flies to the surface of the photosensitive drum 1 due to a potential difference between the photosensitive drum 1 having an electrostatic latent image and the developing roller 5. Then, the electrostatic latent image is visualized in a non-contact manner.

Next, the non-magnetic toner constituting the non-magnetic one-component developer according to the present invention will be described in detail. Non-magnetic toners include colorants and alcohols having 13 or more carbon atoms as polymerizable monomers.
Colored particles obtained by adding a polymerization initiator to a dispersion in which an organic peroxide having a kill group is dispersed, and then subjecting the polymerizable monomer to suspension polymerization in an aqueous medium. Examples of the polymerizable monomer used in the present invention include the following compounds. 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 -Styrene such as -butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene and derivatives thereof; ethylenically unsaturated such as ethylene, propylene, butylene and isobutylene Monoolefins; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; organic acid vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; methacrylic acid, methyl methacrylate, and methacrylic acid Ethyl acrylate, propyl methacrylate, n-butyl methacrylate Methacrylic acid n- octyl, dodecyl methacrylate, 2-ethylhexyl methacrylate,
Methacrylic acid such as stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate; and derivatives thereof; acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, and propyl acrylate , N-octyl acrylate, dodecyl acrylate,
Acrylic acid and its derivatives such as 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate and phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl methyl ketone and vinyl hexyl ketone And N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole and N-vinylpyrrolidone; vinylnaphthalenes; acrylonitrile, methacrylonitrile, acrylamide and the like. These monomers are used alone or in combination of two or more. It is preferable to use styrene or a styrene derivative alone or as a mixture with another monomer in order to enhance the environmental characteristics and durability of the non-magnetic toner.

Examples of the colorant include black colorants such as carbon black, acetylene black, lamp black, channel black, and aniline black;
If a chromatic color, there may be mentioned Farnal Blue, Permanent Blue, Nigrosine Blue, phthalocyanine cyan pigment, rose bengal, xanthene magenta dye, quinacridone magenta pigment, monoazo red pigment, disazo yellow pigment, etc. However, the present invention is not limited to these.

The non-magnetic toner constituting the present invention is manufactured through the following steps. First, a dispersion containing a polymerizable monomer and a colorant is prepared. At this time, it is necessary to add an organic peroxide to the dispersion in order to uniformly disperse the colorant in the polymerizable monomer . In particular, an organic peroxide having an alkyl group having 13 or more carbon atoms in the longest carbon atom chain is required.
is there. Examples of such an organic peroxide include the following compounds. Stearyl peroxide, palmityl peroxide, behenyl peroxide, myristyl peroxide, stearyl peroxyphenoxy acetate, myristyl peroxyphenoxy acetate, α
-Cumyl peroxystearate, α-cumyl peroxy myristate, t-butyl peroxy stearate, t-butyl peroxy myristylate, α-cumyl peroxy behenate, α-cumyl peroxy acetylate, t-butyl peroxybehenate, t-butyl peroxycetylate and the like. The amount of the above organic peroxide used is
It is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the polymerizable monomer.

Colorant and alkyl group having 13 or more carbon atoms
As a method for dispersing the organic peroxide having the above in the polymerizable monomer, a method in which the dispersion is heated while stirring is used. In that case, you may use an ultrasonic dispersion machine etc. together. The heating temperature is 40-140 ° C, and the heating time is 30 minutes to several hours. Next, when a polymerization initiator is added to the dispersion and the polymerizable monomer is subjected to suspension polymerization in an aqueous medium, a non-magnetic toner is obtained. The polymerization initiator used in the present invention is preferably soluble in a polymerizable monomer. Examples of such a polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis-4-methoxy-2, 4-
Dimethyl valeronitrile, other azo-based or diazo-based polymerization initiators, such as benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate, and other peroxide-based polymerization initiators. In the present invention, it is preferable to use a combination of two or more of the above-mentioned polymerization initiators for the purpose of controlling the molecular weight and the molecular weight distribution or controlling the reaction time. If necessary, a water-soluble polymerization initiator such as ammonium persulfate and potassium persulfate may be used in combination. The amount of the polymerization initiator to be used is generally 0.1 to 20 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the polymerizable monomer. When the polymerization initiator is less than 0.1 part by weight, the molecular weight of the product polymer becomes so large that the molecular weight of the product polymer does not satisfy the properties as a non-magnetic toner. On the other hand, when the polymerization initiator exceeds 20 parts by weight, the polymerization product Is not preferred because the molecular weight becomes too low.

The above suspension polymerization reaction is preferably carried out in the presence of a suspension stabilizer. Generally, in suspension polymerization, a surfactant having a hydrophilic group and a hydrophobic group in a molecule is often used as a suspension stabilizer. The suspension stabilizer has a polar group such as a hydroxyl group, a carboxyl group and a salt thereof, a sulfone group and a salt thereof as a hydrophilic group, and is composed of a nonpolar group such as an aliphatic group and an aromatic group as a hydrophobic group. And has the ability to prevent and stabilize the coalescence of the monomer composition particles formed by the granulation process. Examples of such suspension stabilizers include polyvinyl alcohol, casein, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, cellulose derivatives such as ethyl cellulose, starch and derivatives thereof,
Examples thereof include poly (meth) acrylic acid and salts thereof. These suspension stabilizers function to coat the surface of the droplets during the polymerization reaction and prevent coalescence and agglomeration of the droplets.

In producing the nonmagnetic toner of the present invention, a crosslinking agent such as divinylbenzene may be added for suspension polymerization in order to improve blocking resistance and durability. Further, if necessary, a charge control agent may be added. Examples of such a charge control agent include a nigrosine dye, a quaternary ammonium salt or the like if it is positively chargeable, and a metal of an organic compound having a carboxyl group, a sulfonate or a nitrogen-containing group if it is negatively chargeable. Complexes, metal-containing dyes and the like. In the present invention, the suspension polymerization reaction is usually carried out by
The polymerization is performed at a polymerization temperature of 50 ° C. or higher, and the temperature is set in consideration of the decomposition temperature of the polymerization initiator. If the set temperature is too high, the polymerization initiator is rapidly decomposed, which affects the molecular weight and the like, which is not preferable. In addition, neutral salts such as sodium chloride and sodium sulfate may be added to the aqueous medium for the purpose of preventing emulsification. For the purpose of preventing coalescence of the monomer composition particles formed in the granulation step, a thickener such as glycerin or ethylene glycol may be added.

The above non-magnetic toner preferably has a volume average particle diameter of 12 μm or less, preferably 3 to 9.5 μm. If it is less than 3 μm, sufficient fluidity cannot be obtained. On the other hand, if it is larger than 9.5 μm, the reproducibility of pixels such as fine lines and characters deteriorates.

Next, the fine particles adhered to the surface of the non-magnetic toner will be described in detail. The non-magnetic one-component developer according to the present invention adheres to the surface of the non-magnetic toner fine particles containing at least one selected from fine particles of cerium oxide or silicon carbide and magnetic particles. Fine particles of cerium oxide or silicon carbide are desirably used in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the nonmagnetic toner. If the amount is less than 0.1 part by weight, the polishing effect of the fine particles of cerium oxide or silicon carbide on the layer regulating member is insufficient, and the non-magnetic toner is easily fused to the layer regulating member. On the other hand, if it is more than 1 part by weight, the addition is excessive, and the chargeability of the non-magnetic one-component developer may be hindered. The magnetic particles are desirably used in the range of 0.1 to 5 parts by weight based on 100 parts by weight of the non-magnetic toner. If the amount is less than 0.1 parts by weight, the polishing effect of the magnetic particles on the layer regulating member is insufficient, and the non-magnetic toner is easily fused to the layer regulating member. On the other hand, if the amount is more than 5 parts by weight, the addition is excessive, and the chargeability of the non-magnetic one-component developer may be hindered. As magnetic particles, spinel, perovskite, hexagonal, garnet, ferrite having an orthoferrite structure, magnetite, or the like is applied crystallographically. The structure of ferrite is nickel, zinc, manganese, magnesium, copper, lithium, barium, vanadium, chromium,
It is a sintered body of an oxide such as calcium and a trivalent iron oxide. The particle diameter of the fine particles of cerium oxide or silicon carbide and the magnetic particles is preferably in the range of 0.05 to 2 μm.
When the thickness is less than 0.05 μm, the non-magnetic toner easily adheres to the layer regulating member because the polishing effect on the layer regulating member is insufficient. On the other hand, if it is larger than 2 μm, the adhesion to the non-magnetic toner particles is poor, which may cause separation, scattering or fogging. Further, the fine particles to be adhered to the surface of the non-magnetic toner according to the present invention, in addition to the cerium oxide, silicon carbide and magnetic particles, for example, hydrophobic alumina, carbon black, other fine particles such as hydrophobic silica, the non-magnetic toner They may be mixed and used for the purpose of controlling triboelectric charging and controlling conductivity. However, in this case, it is desirable that the ratio of the specific particles composed of cerium oxide, silicon carbide, and magnetic particles to the total fine particles is 0.05% by weight or more.

As means for adhering fine particles containing cerium oxide, silicon carbide or magnetic particles to the surface of the non-magnetic toner, a non-magnetic toner and the above-mentioned particles are mixed at a predetermined ratio, and a turbine type stirrer, a Henschel mixer ,
There is a method of stirring using a stirrer such as a super mixer. Further, as the stirring means, a device called a surface reforming machine such as a Nara hybridization system manufactured by Nara Machinery Co., Ltd. or an angmill manufactured by Hosokawa Micron Corporation may be used. In the present invention, the expression that the particles are attached to the surface of the non-magnetic toner means that the particles are adhered by being sprayed on the surface of the non-magnetic toner, and that at least the particles are attached to the surface of the non-magnetic toner. A state in which a part is buried and fixed. In this case, in order to embed and fix the particles, a surface modifying means such as the above-mentioned Nara Hybridization System manufactured by Nara Machinery Co., Ltd. or Ongmill manufactured by Hosokawa Micron Corporation is used.

[0016]

In order to prevent the non-magnetic one-component developer from being fused to the layer regulating member, the non-magnetic one-component developer needs to have good lubricity in contact and sliding with the layer regulating member. It is. The non-magnetic toner by the suspension polymerization method, which constitutes the present invention, has a good lubricity at the time of contact with the layer regulating member due to its shape because it is a spherical substance. Alternatively, by adhering at least one selected from silicon carbide fine particles and magnetic particles, it is possible to prevent the non-magnetic toner from fusing the developer to the layer regulating member. That is, at the pressure contact portion between the developing roller and the layer regulating member, the resin component of the non-magnetic one-component developer pressed and fused to the layer regulating member is polished by fine particles and magnetic particles of cerium oxide or silicon carbide, and It is possible to prevent the components constituting the developer from being fused.

[0017]

The present invention will be described below with reference to examples. In the examples, parts are parts by weight. Example 1 20 g of stearyl peroxide was dissolved in a mixed solution of 800 g of styrene and 200 g of n-butyl acrylate, and 120 g of carbon black (Mitsubishi Kasei Industries # 40) was further dissolved.
And 30 g of a nigrosine dye (Bontron N04 manufactured by Orient Chemical Co., Ltd.) were added and stirred. With further stirring, the mixture was heated at 40 ° C. for 4 hours. 25 g of 2,2′-azobisisobutyronitrile was added to the obtained slurry.
Was mixed and dissolved. To this solution was added a polyacrylic acid aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd., about 25%, 8000 to 12000 cp, 2
5 ° C.) 80 g and sodium sulfate 45 g were mixed with distilled water 5
A solution dissolved in 000 g was added, and the mixture was stirred at 10,000 rpm for 20 minutes with a stirrer (Homomixer M type) to obtain a dispersion containing a polymerizable monomer and a colorant. This dispersion was added to a 5-liter separable flask equipped with a reflux tube. After the inside of the reaction vessel was replaced with nitrogen for 30 minutes, the mixture was stirred at 300 rpm for 9 hours with a stirrer having a turbine-type stirring blade having a diameter of 50 mm while heating to 95 ° C. Thereafter, while maintaining the stirring, the inner solution was cooled to room temperature, the polymer particles were separated by filtration, washed well with water, and dried to obtain a spherical non-magnetic toner. The particle diameter of the obtained spherical non-magnetic toner is measured with a Coulter counter (aperture 10).
0 μm), the volume average particle diameter of the non-magnetic toner was 6.2 μm. Next, 0.1 part of cerium oxide fine particles (particle size: about 0.5 μm, manufactured by Nikki) was added to 100 parts of the non-magnetic toner.
By stirring with a Henschel mixer for 2 minutes, a non-magnetic one-component developer used in the present invention was obtained.

Example 2 0.3 parts of fine particles of cerium oxide (particle size: about 0.5 μm, manufactured by Nikki) and 0 parts of hydrophobic alumina (RFY-C, manufactured by Nippon Aerosil Co.) were added to the non-magnetic toner of Example 1. .1
A non-magnetic one-component developer used in the present invention was obtained in the same manner as in Example 1 except that 5 parts were simultaneously added.

Example 3 0.3 parts of fine particles of cerium oxide (particle size: about 0.5 μm, manufactured by Nikki) and carbon black (# 40, manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) were added to the non-magnetic toner of Example 1. A non-magnetic one-component developer used in the present invention was obtained in the same manner as in Example 1 except that 1 part was simultaneously added.

Example 4 The procedure of Example 1 was repeated, except that 0.1 part of silicon carbide fine particles (particle size: about 0.5 μm, manufactured by Hakusui Chemical Co., Ltd.) was added to the non-magnetic toner of Example 1. Thus, a non-magnetic one-component developer used in the present invention was obtained.

Example 5 To the non-magnetic toner of Example 1, 0.3 part of silicon carbide fine particles (particle size: about 0.5 μm, manufactured by Hakusui Chemical Industry Co., Ltd.) and hydrophobic alumina (RFY-C manufactured by Nippon Aerosil Co., Ltd.) ) 0.
Except that 15 parts were added at the same time as in Example 1,
A non-magnetic one-component developer used in the present invention was obtained.

Example 6 0.2 parts of silicon carbide fine particles (particle size: about 0.5 μm, manufactured by Hakusui Chemical Industry Co., Ltd.) and carbon black (# 40 manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) were added to the non-magnetic toner of Example 1. A non-magnetic one-component developer used in the present invention was obtained in the same manner as in Example 1 except that 0.1 part was simultaneously added.

Example 7 The procedure of Example 1 was repeated, except that 0.3 parts of magnetic particles (EPT-500 manufactured by Toda Kogyo Co., Ltd., particle diameter: about 0.5 μm) were added to the non-magnetic toner of Example 1. Thus, a non-magnetic one-component developer used in the present invention was obtained.

Example 8 To the non-magnetic toner of Example 1, 0.5 part of magnetic particles (EPT-500 manufactured by Toda Kogyo Co., Ltd., particle size of about 0.5 μm) and hydrophobic alumina (RFY-C manufactured by Nippon Aerosil Co., Ltd.) )
A non-magnetic one-component developer used in the present invention was obtained in the same manner as in Example 1 except that 0.15 part was simultaneously added.

Example 9 With respect to the non-magnetic toner of Example 1, 0.5 parts of magnetic particles (EPT-500 manufactured by Toda Kogyo Co., Ltd., particle size: about 0.5 μm) and carbon black (# 40 manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) 0.1
And a non-magnetic one-component developer used in the present invention was obtained in the same manner as in Example 1 except that parts were simultaneously added.

Comparative Example 1 Raw materials were mixed in the following composition, and were subjected to hot melt kneading with an extruder, followed by pulverization and classification to obtain an average particle diameter of 6.5 μm.
m of non-magnetic toner was obtained. The non-magnetic toner was used as a non-magnetic one-component developer for comparison.

Comparative Example 2 To 100 parts of the non-magnetic toner of Comparative Example 1, 0.3 part of hydrophobic alumina (RFY-C manufactured by Nippon Aerosil Co., Ltd.) was added and mixed in the same manner as in Example 1. Thus, a non-magnetic one-component developer for comparison was obtained.

Comparative Example 3 The non-magnetic toner of Example 1 was directly used as a non-magnetic one-component developer for comparison.

Using a non-magnetic one-component developer obtained by the above operation, a remodeling machine (developing bias of a commercially available magnetic printer (trade name: L-880 manufactured by Kyocera Corporation) having a developing mechanism shown in FIG. A print test was carried out using a DC voltage of -100 V and a surface potential of the photoconductor modified to -900 V). In each of the non-magnetic one-component developers of Examples 1 to 9, the developer did not fuse to the layer regulating member. On the other hand, in the non-magnetic one-component developers of Comparative Examples 1 to 3, the developer was fused to the layer regulating member and scattered. Table 1 shows the results obtained by measuring the solid image of the non-magnetic one-component developer transferred from the photosensitive drum onto the transfer paper with a Macbeth reflection densitometer and the fog results of measuring the non-image portion with a Hunter colorimeter. . As is clear from Table 1, it was confirmed that the non-magnetic one-component developing method of the present invention had a sufficient image density and reduced fog as compared with the comparative example.

[0030]

[Table 1]

[0031]

According to the present invention, as described above, the number of carbon atoms is 13 or more.
Addition of an organic peroxide having an alkyl group to the polymerizable monomer
Then, by using a non-magnetic one-component developer in which specific fine particles are mixed and adhered to a spherical non-magnetic toner by a suspension polymerization method in which a polymerization initiator is added , the developer is fused to the layer regulating member. There was no adhesion and good development characteristics were obtained.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a non-contact type non-magnetic one-component developing apparatus for carrying out the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor drum 2 hopper 3 non-magnetic one-component developer 4 layer regulating member 5 developing roller 6 developer leakage preventing member 7 stirrer

Continuation of the front page (56) References JP-A-3-293364 (JP, A) JP-A-4-9070 (JP, A) JP-A-60-179748 (JP, A) JP-A-53-81127 (JP) , A) JP-A-4-338977 (JP, A)

Claims (1)

(57) [Claims] 1. A non-magnetic one-component developer is supplied to a developing roller, and a thin layer of the non-magnetic one-component developer is formed on a surface of the developing roller by a layer regulating member and is given an electric charge. A non-contact type non-magnetic one-component developing method in which the non-magnetic one-component developer is caused to fly by a potential difference with the photosensitive drum holding an electrostatic latent image in a non-contact manner, and then transferred to a transfer material. An organic peracid in which the non-magnetic one-component developer has an alkyl group having 13 or more carbon atoms
After adding and dispersing the compound to the polymerizable monomer, the polymerization initiator
Characterized in that fine particles containing at least one selected from cerium oxide, silicon carbide and magnetic particles are adhered to the surface of a non-magnetic toner obtained by a suspension polymerization method to which Magnetic one-component development method.